What Are the Different Types of Herpes Medication?
HerpesSimplex is a viral skin disease caused by the viral herpes virus. Divided into herpes simplex and shingles, herpes simplex (herpessimplex) is a skin disease caused by herpes simplex virus, which invades the junction of skin and mucous membranes, and presents as localized clustered vesicles and herpes zoster ) Is caused by herpes virus, dense viral vesicles and neuralgia distributed along the peripheral nerve bands, and local lymphadenopathy are the main features of acute viral skin disease.
Viral herpes
- HerpesSimplex is a viral skin disease caused by the viral herpes virus. Divided into herpes simplex and shingles, herpes simplex (herpessimplex) is a skin disease caused by herpes simplex virus, which invades the junction of skin and mucous membranes, and presents as localized clustered vesicles and herpes zoster ) Is caused by herpes virus, dense viral vesicles and neuralgia distributed along the peripheral nerve bands, and local lymphadenopathy are the main features of acute viral skin disease.
Etiology of viral herpes
- The disease is caused by the viral herpes (Herpes Simplex Virus, HSV) of the DNA virus. Human viral herpes is divided into two types, namely viral herpes type (HSV-) and viral herpes type (HSV-). Type I mainly causes infections of skin, mucous membranes (oral mucosa) and organs (brain) outside the genitals. Type mainly causes skin and mucous membrane infections in the genital area. These two types can be determined by fluorescent immunoassay and cell culture method.
- Humans are the only natural host of viral herpes. The virus enters the body through the asthmatic tract, oral cavity, genital mucosa, and broken skin. It inhabits the human recreational mucosa, blood, saliva, and learns that it knows the ganglion cells. Primary infections are mostly recessive, and most are asymptomatic or subclinical, with clinical symptoms appearing only in individuals. After the primary infection occurs, the virus can remain in the body for a long time. About 50% of healthy people are carriers of the virus. HSV does not produce long-lasting immunity in the human body. Whenever the body's proportional force decreases, such as fever, gastrointestinal disorders, menstruation, pregnancy, lesion infection, and motivational changes, the hidden HSV in the body is activated and becomes ill.
- Studies have shown that patients with recurrent viral herpes can have cellular immune deficiency. HSV- is usually thought to be associated with cervical cancer.
Pathogenesis of viral herpes
- Herpes simplex is caused by the herpes simplex virus (divided into type I and type II). The human body is its only natural host. When the body's resistance decreases, the disease is promoted. The pathological manifestations are intraepidermal blister, epidermal necrosis, and multinucleated epithelium. Inflammation of cells, eosinophilic nucleus inclusion bodies, and significant neutrophils and lymphocytes. Shingles is activated by the latent varicella-zoster virus in the body. This virus has been latent in the nerve cells of the body for a long time since it first infected the patient. It is induced when the immune function is low. Its histopathology is similar to the former, but the latter The inflammation is heavier than the former.
Clinical manifestations of viral herpes
- Herpes simplex is clinically divided into two types, the original type and the recurrent type. The original type is herpes gingival stomatitis, herpes external vaginitis, inoculated herpes simplex, herpes eczema, disseminated herpes simplex, and newborns. Herpes, etc.
- Viral herpes
- After HSV, immunity can be quickly generated. The lesions are limited to the surface of the skin and mucous membranes, and HSV occurs in newborns and people with immunodeficiency (such as organ transplants, patients receiving immunosuppressive agents and antitumor treatment) whose immune function is not yet mature. When infected, the lesion often spreads throughout the body, such as the brain, liver, lungs, eyes, adrenal glands, and skin and mucous membranes. It is very ill and has a high mortality rate. When the skin has extensive damage such as eczema and burns, HSV infection often manifests as generalized herpes of the skin and mucous membranes, and can cause systemic disseminated lesions with a serious condition. In pregnant women with genital herpes, HSV is transmitted to the fetus through an ascending infection of the cervix, causing congenital infections, causing stillbirth, miscarriage, premature birth and congenital malformations. The virus can also cause neonatal infections through the birth canal during delivery. The incubation period of HSV infection is 2-12 days, with an average of 6 days. Different clinical types may have different clinical manifestations.
Diagnosis of viral herpes
- According to the clustered blisters at the junction of the skin and mucous membranes, the subjective symptoms are mild and the skin lesions have a burning sensation. The disease course is short, recurring, and can occur when fever or gastrointestinal disorders occur.
Viral herpes treatment principles
- Systemic treatment of herpes simplex should be symptomatic, antiviral and immunotherapy. Local treatment is based on the principles of dryness, convergence and prevention of infection. Corticosteroid hormone ointment should be avoided because it can inhibit interferon in serum.
- Shingles should also be treated with systemic and local therapies. The principles are antibacterial virus, anti-inflammatory, analgesic, local protection, prevention of secondary infection, shortening the course of disease, etc.
Viral herpes commonly used drugs
- Herpes simplex
- Topical
- Antiviral agent: 40% herpes solution of dimethyl sulfoxide, acyclovir, phthalobutylamine, blazepam, etc.
- Antibacterial and antipruritic agents: camphor, gentian violet, calamine lotion, etc. Anti-infectives antibiotics
- Internal use
- Antiviral agents: acyclovir, arabinosine, interferon, interferon inducer, etc.
- Immunization agents: levamisole, transfer factors, etc.
- Shingles
- Systemic medication
- Analgesics: cranial pain, analgin, carbamazepine, amitriptyline, doxepin, imipramine, amide imidazine, phenytoin sodium, cyprotin, Telten, etc.
- Antiviral agents: morpholinidine, cytarabine, acyclovir and the like.
- Immunization agents: transfer factor, placental globulin, gamma globulin immune serum, etc.
- external use
- Analgesics: 1% dacronin, 5% benzocaine, 1% phosphoacetic acid, blazepine, etc.
Viral herpes treatment
- For the treatment of viral herpes, there are still many problems left unsolved. The treatment has not completely eliminated the virus and prevented the recurrence of the disease. The current treatment is divided into general treatment, antiviral treatment and traditional Chinese medicine treatment, these treatments are all necessary. General treatment is actually symptomatic treatment, while antiviral treatment is cause treatment. Traditional Chinese medicine and traditional Chinese medicine treatment are mostly based on syndrome differentiation, and both the symptoms and the symptoms can effectively prevent recurrence.
- Oral administration, 0.2 g / time, once / 4 hours or 1 g / d, divided. The course of treatment depends on the condition, ranging from a few days to half a year. Decrease the amount of renal insufficiency.
- Intravenous infusion, 5mg / time, added to 5% -10% glucose injection. The instillation time is 1 hour, once every 8 hours, for 7 consecutive days. Children under 12 years of age are administered at a dosage of 0.25g / m2. Renal insufficiency is reduced; creatinine clearance is reduced to once every 24 hours from 10 to 25 ml / m2 per minute; clearance is reduced to 2.5 mg / kg from 0 to 10 ml / m2 per minute and administered every 24 hours .
- Adverse reactions and precautions: Intravenous administration, occasional drug rash, nausea, sweating, hypotension, hematuria and creatinine levels increased, and returned to normal after discontinuation. There are no obvious adverse reactions when taken orally, and probenecid can slow the excretion of the product, prolong the half-life, and accumulate drug in the body.
- Dosage form and specifications] Tablet: 0.2g / tablet, 0.4g / tablet. Capsule: 0.2g / powder. Powder injection: (lyophilized sodium salt), 0.25g / piece, 0.5g / piece. Eye drops: 0.1%, 8ml / bottle.
- Adenosine (Vidarabine)
- Function and use: After entering the human body, it is phosphorylated in cells to form mono-, di-, tri-, and phosphate, which then competitively inhibit the bacterial DNA polymerase activity.
- Internal dynamics: after intravenous drip, nitrogen is rapidly removed in the body to become arabinose hypoxanthine, and
- Shingles
- Dosing schedule: intravenously, 10-15mg / kg.d, dissolved with 5% glucose injection, diluted to 0.7mg / ml and dripped, finished in 8-12 hours, the course of treatment is 5-15 days. Shingles: 10mg / kg, for 5 consecutive days, also dissolved with grapevine injection.
- Adverse reactions and precautions: gastrointestinal and neurological reactions, which have an effect on liver and kidney function, inhibit bone marrow and cause teratogenesis, pregnant women are disabled, prominent adverse reactions are myalgia, nausea, vomiting, loss of appetite, weakness , Weight loss, tremor. Allopurinol has xanthine oxidase inhibitory effect, and the elimination of right arabinose hypoxanthine slows down and accumulates, which can cause more serious neurotoxicity reactions.
- Dosage form and specifications: Injection (powder injection): 0.2g / bottle, 0.5g / bottle, 1g / bottle. Injection: 1g: 5ml.
Viral herpes common sense
- Treatment of several viral herpes
- Herpes simplex is called "heat sore" in traditional Chinese medicine. It occurs at the junction of skin and mucous membranes, especially in the corners of the mouth, lips, and around the nostrils. It is characterized by clusters of small blisters on the basis of erythema, mostly clusters. The blister is transparent and turbid at first, and then eroded, nourished, and crusted after rubbing, and secondary infection may also occur. The course of disease is about 1-2 weeks, and it can recur in situ after healing.
- Hand, foot and mouth disease mostly occurs in pre-school children, especially infants aged one to two. The blisters are the size of sesame, and the blisters are pearly white with red circles around them. It mainly occurs in the flexion of the fingers (toes), the side edges, and the soles of the palms of the hands; the oral mucosa and small blisters in the tongue are easily ulcerated and ulcers are formed. Conscious pain affects eating and infants often drool. The entire course of the disease is about one week and rarely recurs.
- Shingles first has local skin tingling for 1-5 days, and then clusters of small clusters of blisters appear on the face or chest, back, waist and abdomen. The distribution is limited to one side of the body, arranged in a band, and the pain is often severe. After one week, the blisters will begin to dry out and scab, and then they will exfoliate and heal. It usually takes 2-3 weeks. The elderly can have neuralgia. There will be permanent immunity after healing, so no recurrence.
- Chickenpox is common in children under 10 years of age. The blisters are the size of mung beans and are mainly distributed on the head, face, trunk, and the proximal parts of the extremities. The blisters are clear as water droplets on the lotus leaf at first, and then become cloudy. The walls of the blisters are thin and fragile. After 2 to 3 days, the blisters gradually
- Viral herpes
Viral herpes simplex herpes simplex
- Herpessimplex is a common viral infection in children. It is common in all parts of the world. It can be found in local areas such as the skin, oral mucosa, and cornea. It can also cause systemic infection and threaten life.
Causes of viral herpes
- The pathogen is herpesvirushominis, which contains DNA and is morphologically similar to cytomegalovirus, varicella-zoster virus, and Epstein-Barr virus. Many small animals such as rabbits, guinea pigs, cotton rats, mice and voles can be infected. Corneal inoculation in rabbits can cause keratoconjunctivitis. Tissue culture can be performed with chicken embryos, human amniotic cells, human kidney cells, rabbit kidney cells, and rabbit corneal cells. Typical cell lesions are seen, characterized by cell degeneration and agglutination, typical nuclear inclusions and giant cells. . Two types of antigens have been identified: Herpes simplex virus type 1 (HSV-1), which mainly infects the skin and mucous membranes of the mouth, lips, and central nervous system, and occasionally can be found in the external genitalia.
- Herpes simplex virus type 2 (HSV-2) is generally associated with external genital infection and neonatal infection, and occasionally occurs in oral lesions. The virus is widely parasitic on the human body, and minor injuries and close contact are the main factors that spread the infection. The virus can be isolated from a patient's saliva, skin lesions, and stool. Infections are spread particularly in poorly sanitary homes or nurseries. The age of onset is 1 to 4 years, especially in the second year after birth. No obvious seasonality.
Pathogenesis of viral herpes
- Susceptible people have no special antibodies for this disease, and can get primary herpes simplex infection. After the virus invades the human body for the first time, temporary viremia occurs, but the vast majority of patients (over 90%) are only recessive infections without symptoms. There are only a few clinical symptoms, including gingivostomatitis, skin herpes, keratoconjunctivitis, vulvovaginitis, meningoencephalitis, and visceral herpes infections. Because the virus persists in the body (generally considered to be in the peripheral nerves) and has specific antibodies, both recessive and dominant patients become the majority of the population with the virus. These people with the virus are usually not ill, but when the physical strength is weak, adverse environmental factors such as fever, sunlight, injuries, cold, indigestion, menstruation, mental distress or the application of immunosuppressants can cause lips, cheeks, and vulva Herpes may repeat these symptoms and spread the virus to susceptible contacts. Recurrence generally lacks systemic symptoms.
- Infants less than 6 months of age, except for premature babies, often transmit maternal antibodies in the serum, so they rarely occur, even if they occur, the symptoms are not significant. After 1 year of age, the disease is more common, most of which are secondary to upper respiratory tract infection, pneumonia, enteritis or other acute infectious diseases. By adolescence, about 90% have serum antibodies.
Clinical manifestations of viral herpes
- The incubation period is 2 to 20 days, with an average of 6 days.
- Common Symptoms Gingival stomatitis (herpeticgingivostomatitis) is a common type of primary infection in children. It is mostly found in the cheeks, lips, or gums, and can also invade the skin around the lips. At the time of the onset, the blood was congested first, and then round follicles with a diameter of about 2 mm were formed, which quickly ruptured into superficial ulcers, which contained traces of fibrous exudate. Sometimes involving the tongue and soft palate, lymphadenopathy of the submandibular and anterior neck can also occur, with tenderness. Due to local pain, irritability and antifeeding are often manifested. In addition, there are fewer general symptoms, but in primary cases, especially in malnourished and immune-deficient children, the disease is more severe, and dehydration and acidosis can occur. The fever can reach 39-40 ° C and the heat course can be 2 to 3 days. After 3 to 4 days, the pain was mostly relieved, and healed in 2 to 6 days. Local lymphadenopathy lasts longer, sometimes it can be prolonged for 2 to 3 weeks.
- Rare symptoms Primary infections can also occur in the following locations, but are less common. Lung infections are very rare.
- Keratoconjunctivitis: Seeing eyelid redness and swelling with small blisters. Dendritic ulcers and swollen lymph nodes before the ear appear when the cornea is involved. If the lesion is limited to the conjunctiva, most of them recover within 2 weeks, but if the cornea is damaged, it can affect vision, even scarring, and can cause blindness.
- UlVulvovaginitis: The vulva is generally red and swollen, with a shallow flat ulcer of 3 to 4 mm. After 2 weeks, it becomes dry.
- (3) meningoencephalitis: herpes meningoencephalitis is rare, and symptoms can be mild or severe. Those who are mild are similar to benign aseptic meningitis syndrome (see Coxsackie and Ecovirus infection chapter). Difficult speech, disorientation, ataxia and dysfunction of the autonomic nervous system, convulsions and paralysis of one side can be seen in some cases, and optic papillary edema often occurs. Sometimes it can be confused with brain tumors in diagnosis.
- Eczemahepeticum (eczemahepeticum, kaposi'svaricelliformeruption): This is the infection of herpes simplex virus on the basis of infant eczema, which can cause diffuse varicella-like rash. Its typical symptoms are acute fever onset, irritability, followed by partial approval. Herpes and pustules appeared, herpes ruptured within a few days, and dried up around the 8th day after the onset, and the fever subsided naturally. After 3 weeks, the palate was detached, and the original eczema continued. Previously, this condition often needed to be distinguished from eczema.
- Systemic infection: Herpes virus systemic infection can occur in newborns who are born prematurely, malnourished infants or children with cellular immunodeficiency diseases (including children with leukemia, other malignancies, or visceral transplantation). Fever (or hypothermia), progressive jaundice, hepatosplenomegaly, vomiting, lethargy, followed by dyspnea and circulatory failure usually begin 5 to 9 days after birth. At the same time, neurological symptoms such as convulsions can occur. Purple scars can occur due to poor liver function or thrombocytopenia. Such cases can not invade the body surface and lack skin or mucous membrane herpes, so the diagnosis is easily delayed. Severe cases have a short duration and can die within 2 to 4 days. May also be complicated by Pseudomonas aeruginosa sepsis. Pathogens can be isolated from the internal organs.
- Disseminated herpes infections seen in the neonatal period are mainly due to HSV-2, which is rare. Neonatal cases can develop the infection as they pass through the mother's birth canal, or they can be transmitted through contact with family herpes patients.
- Recurrent herpes infection: Recurrent cases that occur during physical decline are far more common than primary ones. They are mainly found on the lips, but also on other skin and mucous membranes. They are generally not accompanied by fever or other systemic symptoms, and only occasionally cause discomfort. Or local neuralgia. The rash turns from blisters to pustules and scabs, develops rapidly, and is milder than the primary case, and local lymphadenopathy is also rare. When recurrent lesions occur, serum-specific antibodies generally remain at their original levels, with only a few cases showing increased titers.
Viral herpes laboratory test
- When hematoma has severe gingival stomatitis, meningoencephalitis, or herpes eczema, the total number of white blood cells slightly increases.
- Cerebrospinal fluid examination of cerebrospinal fluid in patients with meningoencephalitis showed increased lymphocytes, increased protein, and normal sugar levels, similar to other types of aseptic meningitis syndrome.
- For prionology and serological examinations, see the diagnosis and differential diagnosis section below.
Viral herpes diagnosis
- The diagnosis of primary herpes simplex is based on the following:
- In children with fever and other systemic symptoms, if a vesicular rash appears at the same time, the disease should be suspected. Special attention should be paid to the lips and the skin and mucous membranes nearby. It is even more suspicious to see small follicles or ulcers in the cheeks and gums.
- Pathogens can be isolated from local lesions (including vesicular fluid, throat swabs, cerebrospinal fluid, etc.) within 4 days. If the virus is unconditionally isolated, the contents of the vesicles can be inoculated into the corneal scratches of the rabbit. If the corneal cell smear is examined, typical eosinophilic inclusions can be confirmed, which can confirm the diagnosis.
- Take a scrape specimen from herpes or ulcers, smear for microscopic examination, staining with hematoxylin and eosin can reveal typical nuclear inclusions and multinucleated giant cells, and the pathogen can also be confirmed by immunofluorescence or electron microscopy.
- Duplicate serum tests are very helpful for primary infections. Generally, antibody titers in the healing phase are four times or higher than those in the acute phase.
- Herpes simplex stomatitis must be distinguished from herpes angina caused by enterovirus, which is prevalent in summer and autumn. It is mainly caused by sudden fever, antifeeding, salivation, and pain during swallowing. Occasionally, vomiting and diarrhea are present. The lesions mainly occur in the pharyngeal isthmus and soft palate, and do not involve the buccal mucosa, tongue, and gums like herpes simplex, so identification is easier. In addition, it should be distinguished from infectious impetigo that affects the lips and nostril, and candida albicans vulvovaginitis confined to the vulva.
Viral herpes treatment
- General treatment to keep the mouth and skin clean. If necessary, apply traditional Chinese medicine tin powder, and occasionally give systemic analgesics. When dehydration and acidosis occur, appropriate fluid therapy should be considered. Antibiotics do not affect the course of herpes infection, but they can be used for a short period of time when secondary bacterial infections occur. High-dose gamma globulin has been used to treat neonatal cases with no effective results. Corticosteroids for acute herpetic keratoconjunctivitis can aggravate the condition whether used systemically or locally.
- Specific treatment
- Herpes net: 0.1% idoxuridine (IDU) solution to treat keratoconjunctivitis, eye drops once an hour during the day, once every 2 to 3 hours at night, 1 to 2 drops each time, it works quickly. After the local symptoms disappear, the drug should be continued for several days. Although IDU cannot kill herpes virus, it can hinder DNA synthesis and prevent the virus from multiplying. The natural recovery period of keratitis is 2 weeks, and it will be effective within 3 days after IDU treatment. Herpes® does not prevent recurrence of the infection.
- Adenosine: Use of adeninearabinoside (vidarabine, ara-A) in the early cases of herpesvirus encephalitis or neonatal herpesvirus infection, which has a significant effect, but it must be done before the encephalitis case is unconscious. It works. The dose is 15 mg / (kg · d), intravenous drip, 12 hours daily for 10 consecutive days. If administered immediately within 3 days after the onset of neurological symptoms, disseminated cases can also be controlled, which can reduce mortality and neurological sequelae. This drug can significantly reduce mortality in neonatal cases. It is also effective for herpes keratitis, but this medicine has no effect on local treatment of recurrent herpes labialis. Adenosine is better than cytosinearabinoside (ara-C), which has immunosuppressive effects and has a toxic response to bone marrow, while the former has few side effects. But adenosine did not work in advanced cases. It should also be noted that sometimes systemic symptoms appear before the rash, and it is not appropriate to wait for a typical rash before starting treatment.
- Acyclovir (acyclovir, acycloguanosine): It is more effective than ara-C. In early cases, only drowsiness and no coma use acycloguanosine [30mg / (kg · d), divided into 3 intravenous injections, combined with 10 ~ 12 days] can reduce the mortality of herpes simplex virus encephalitis.
Viral herpes zoster
- Shingles (HerpesZoster) is a viral infection, also known as lumbar entrapment, string sores, spider sores, etc.
- The disease is caused by varicella-zoster virus (VZV). Currently considered
- Viral herpes
Clinical manifestations of viral herpes
- Occurs in the spring and autumn seasons, more common in adults. Before the rash, there are often precursor symptoms such as fever, burnout, and poor food. After 1-3 days, the affected area becomes flushed, and most clusters of millet to mung bean-like papules appear, which quickly turns into blisters, and the blister wall is tense. Bright, transparent and clarified content, not mutually integrated. The rash is distributed along the cutaneous nerve, with unilateral rashes that do not exceed the midline of the body surface, and are mostly arranged in irregular bands. It is common in intercostal nerves, cervical nerves, trigeminal nerves and lumbosacral nerve innervation areas, such as face, neck, chest and back, waist and abdomen. It can also invade the eyes, ears, oral cavity and genital mucosa, and neuralgia is one of the characteristics , Can occur before or accompanied by rash. Pain radiates along the affected nerves. Elderly patients often experience neuralgia for a long time after the damage subsides. The course of the disease takes about 1-2 weeks. After healing, temporary pigmentation can be left behind without leaving scars. It can also cause erosion or secondary infection due to blister rupture. A few clinical manifestations are atypical, the common ones are:
- Incomplete herpes zoster (stupid type), with only erythema, pimples, and no typical blisters.
- Bullous shingles can form pea-to-cherry blisters.
- hemorrhagic shingles with bloody contents.
- Gangrene-like shingles, gangrene occurs in the center of the rash, and the black rash is not easy to peel off, leaving scars after healing.
- Disseminated herpes zoster, in patients with malignant tumors or old and weak, within a few days of local rash, a chickenpox-like rash appears throughout the body, often accompanied by high fever, which can be complicated by lung and brain damage. Cause death.
The main types of viral herpes
- Squint herpes zoster
- Herpes zoster is sporadic, and it is common to distribute gum from September to November. Clinically seen herpes zoster is associated with the first trigeminal nerve involvement. Red eyelid swelling, conjunctival congestion, blisters, and crusts can be seen, which can involve corneal ulcerative keratitis, and blindness due to scar formation. Severe cases can occur pancreatitis, encephalitis, and even death.
- Ear shingles
- Also known as Remsay-Hunt syndrome, is caused by VZV invasion of the facial and auditory nerves. The clinical features are sharp ear pain and ipsilateral paralysis, occasional hearing loss, and dizziness. May be accompanied by fever, swelling of the local lymph nodes and costal glands.
- Herpes zoster meningitis
- The virus is caused by the retrograde invasion of the central nervous system directly from the anterior and posterior roots of the spinal cord. Most often seen in patients with cranial nerve neck or upper thoracic spinal cord segment invasion. It indicates that there are headache, vomiting, convulsions or other progressive sensory disturbances, but also ataxia and other cerebellar symptoms.
- Visceral shingles
- The virus invades the posterior root of the spinal cord and the visceral nerve fibers of the sympathetic and parasympathetic nerves, causing gastrointestinal or urinary symptoms. When the pleura and peritoneum are violated, irritation symptoms or even effusions occur.
Introduction to viral herpes
- Identification of herpes simplex and shingles:
- Herpes simplex occurs frequently at the junction of the skin and mucous membranes, and is not distributed along the nerve. It often recurs. It is more common in patients with febrile diseases, gastrointestinal disorders, and irregular menstruation.
- The onset of shingles is suddenly or firstly painful. The damage is cluster mung bean-sized blisters on inflammatory erythema, papules, bullae, or blood vesicles appearing between them. The skin between the groups is normal. Distribution, more common unilateral, more common in the intercostal nerve and trigeminal nerve area, the intersection of the upper limb brachial plexus nerve and lower limb sciatic nerve area, occasionally can affect the eye, causing keratitis, iritis, pancreatitis, etc. From 2 to 3 months or more, the local lymph nodes are often enlarged and tender, and in severe cases, they can have fever and pain to varying degrees.