kuru disease
Introduction
Introduction to Kuru disease Kuru disease is only found in the Fore ethnic group in the eastern plateau of New Guinea, with a population of only 30,000 to 40,000, due to religious ceremonies participating in cannibalism. In 1 year, more than 200 people died of tremors and dysfunctional walks. The locals called this Kuru. In the United States, NIHGajdusek in view of Kuru brain changes and sheep scrapie is very similar, but Kuru brain was ground and inoculated into the brain of the orangutan, 13 months after the animal developed. He believes that the pathogen of the disease is a special kind of lentivirus called extraordinary lentivirus. At present, this disease has been favored as a transmissible neurodegenerative disease caused by mutant prion protein, also known as prion disease or protein particle disease, thus negating the unusual lentivirus infection theory advocated by Gajdusek many years ago. basic knowledge The proportion of sickness: 0.0001% - 0.0003% Susceptible people: no specific population Mode of infection: digestive tract spread complication:
Cause
Cause of Kuru disease
(1) Causes of the disease
It is believed that the scorpion venom itself can enter itself or spontaneously due to genetic variation. For infectious prion diseases, scorpion venom can enter the human body through oral, injection or surgical procedures, and invade the scorpion after entering the human body. Possible pathways for brain tissue include direct neurotransmission from the site of infection, first replication in the mononuclear macrophage system followed by neuronal spinal cord diffusion and blood-borne diffusion.
(two) pathogenesis
The pathogenesis of scorpion venom disease is still not very clear. The starting point of scorpion venom is PrPsc transformation of PrPc, which makes PrPsc accumulate in the central nervous system. How does PrPsc cause nerve cell damage remains to be elucidated? Related research suggests that PrPsc has Neurocytotoxicity can cause neuronal apoptosis (apoptosis); PrPc is soluble, transformed into insoluble PrPsc, precipitates into amyloid plaques in brain tissue and causes damage; complex formed by the combination of PrPc and copper atoms It has a similar activity to superoxide dismutase (SOD). When PrPc is changed to form PrPsc, it causes PrPc deficiency, which reduces the SOD activity of nerve cells, thereby increasing the sensitivity to oxidative damage caused by superoxide and the like, and allowing nerves. The sensitivity of cells to the toxicity of high glutamic acid and high copper increases, eventually leading to neuronal degeneration and death.
Prevention
Kuru disease prevention
In view of the fact that there is no effective treatment for scorpion venom disease, it is extremely important to prevent it. There is no vaccine-susceptible population.
1. Control the source of infection to slaughter scorpion venomous diseases and suspected sick animals, and properly handle the carcasses of animals, effectively killing scorpion venom methods including incineration, autoclaving at 132 ° C for 1 h, 5% calcium hypochlorite or 1 mol /L sodium hydroxide for 60min soaking, etc.; restricting or prohibiting the production of medical products derived from blood products and animal materials in infected areas; patients with scorpion venom and any neurodegenerative diseases, who have received organ extracting hormone therapy, Those with a family history of scorpion venom and those who have lived in the affected area for a certain period of time are not allowed to serve as donors of organs, tissues and body fluids; they are monitored for hereditary prion family, and genetic counseling and eugenics screening.
2. Cut off the transmission route to eliminate the abuse of human tissue, do not eat animal meat and products of scorpion venom disease, do not feed animals with animal tissue feed, medical procedures strictly follow the disinfection procedures, and advocate the use of disposable neurosurgical instruments.
Complication
Kuru disease complications Complication
Ataxia, tremors, dementia, due to mental, consciousness, and intellectual disabilities, can lead to dysfunction and disorders of various systems, such as eating difficulties, cough, lung infections, long-term bed-ridden sores.
Symptom
Kuru disease symptoms common symptoms debilitating involuntary movement gait instability dysphagia dementia eyeball tremor muscle atrophy movement disorder trembling insomnia
The clinical course of Kuru disease is very regular, the cerebellar ataxia gradually gains weight, and finally the patient loses exercise ability and dies. The course of the disease is usually from March to September, and can usually be divided into three stages:
The first stage is the walkable period. Before others discover the abnormality of the patient, the patient first notices that he is ill. Some patients complain of forehead symptoms such as headache and limb pain. The patient feels that the standing and gait are unstable, and often he still feels conscious. Voice, abnormal movement of the hands and eyes, tremor of the trunk, gait and ataxia cause instability, the earliest symptoms of the disease, ambiguous speech (consonant dysfunction), and gradually gain weight, eye movement disorders However, there is no real nystagmus; the patient often presents with esotropia and persists. The tremor is initially indistinguishable from chills. The patient is excessively trembling. The movement disorder occurs first in the lower limbs and then gradually affects the upper limbs. The patient often cripples when standing up, as if angry. In order to maintain balance while standing, the toes firmly grasp the ground, and can not stand on one foot for a few seconds at the beginning of the disease. This is a useful clue to the diagnosis of this disease. Most patients still work in the garden at this stage. In order to engage in its normal activities and participate in the social life of the village, at the end of this stage, the patient can walk around the village without a helper.
The second stage is the stage of sitting and doing things. The patient can't walk without the help of others. The tremor and movement disorders increase weight, and the rigidity of the limbs often develops, accompanied by extensive clonic or occasional shock-like muscle involuntary movement. Occasionally, acromegaly and chorea-like movements occur especially when the patient is overly panicked due to unstable posture, and even when suddenly stimulated by noise or strong light, deep tendon reflexes are normal, Babinski is negative. There are usually sputum, and knee sputum is also common. Although muscle activity is rare, there is no bundle or true weakness and muscle atrophy. Patients often have emotional instability and can lead to pathological laughter, smile and Laughter slowly stops. This symptom is sometimes seen in the first stage of the disease. Therefore, the newspaper gives the disease an inappropriate synonymous name - laughter, most patients succumb to their disease, carefree Attitude, almost true spirit (happy), some patients, especially young and young male adults, depressed, individual patients to family members or others Adopt aggressive attitude pathological, patients significantly slow thinking, but no serious dementia found no patient had paresthesia.
The third stage is the end of the disease. This period starts from the patient's own inability to sit up, the movement is disordered, the tremor, the speech disorder is more serious, the patient loses the ability to move, the sputum reflexes, the grip reflection occurs, and some patients exhibit pyramidal tracts. Posture and movement disorders, in the end, two incontinence, dysphagia caused by hunger and thirst, the patient's weakness, malnutrition and medullary involvement symptoms, dumb, loss of reactivity, mostly due to hemorrhoids and fallopian pneumonia.
Examine
Kuru disease check
1. Histopathological examination of lesions of brain tissue can be seen in cavernous vacuoles, amyloid plaques, nerve cell loss with gliosis, minimal leukocyte infiltration and other inflammatory reactions.
2. Immunological examination A variety of immunological methods, such as immunohistochemistry, immunoblotting, enzyme-linked immunosorbent assay (ELISA), etc., have been used to detect PrPsc in tissues, anti-PrP27-30 antibody, can be used in isosulfur PrPsc was detected in the diseased tissue after guanidine cyanate and autoclave or proteinase K digestion and dissolved PrPc. Monoclonal antibody 15B3 can only bind to PrPsc, so PrPc and PrPsc can be identified without treatment of dissolved PrPc, including brain and spinal cord. , tonsil, spleen, lymph nodes, retina, conjunctiva and thymus and other tissues, using Western blotting method, can detect a more characteristic brain protein 14-3-3 in cerebrospinal fluid, this protein is a kind The neuronal protein which can maintain the stability of other protein configurations is abundant in normal brain tissue but does not appear in the cerebrospinal fluid. When the scorpion venom is infected, a large amount of brain tissue is destroyed, so that brain protein 14-3-3 leaks into the cerebrospinal fluid.
3. Animal inoculation test The suspicious tissue homogenate is intracerifred or orally inoculated into animals (usually used rats, sheep, etc.) to observe the incidence of the vaccinated animals. After the onset, the brain tissue biopsy has the characteristic pathology of scorpion venom disease. Change, the sensitivity of this method is limited by the inter-species barrier and takes a long time.
4. Molecular biological examination DNA was extracted from peripheral blood leukocytes of patients, PCR amplification and sequencing of PRNP were carried out, and PRNP characteristic mutations of familial hereditary prion diseases were found.
Electroencephalography, brain topography, single photon emission computed tomography (SPECT), CT, magnetic resonance and positron emission tomography (PET) are helpful for diagnosis and identification.
Diagnosis
Diagnosis and diagnosis of Kuru disease
Diagnostic criteria
The diagnosis of scorpion venom depends on the pathological examination of brain tissue, so it is difficult to diagnose before birth.
1. Epidemiological data
Eating foods of suspected animal origin of mad cow disease, receiving organ transplants from donors that may be infected with scorpion venoms, or electrode implantation procedures that may be contaminated with scorpion venoms, using human hormones derived from organs and families with prion diseases History, all help the diagnosis of this disease.
2. Clinical manifestations
Although most of the scorpion venoms are characterized by progressive dementia, ataxia and myoclonus, but different scorpion venoms have their own characteristics, such as sporadic gram-ya disease, the age of onset is large, There is ataxia after dementia, and the age of new variant Ke-Ya disease is milder; Kuru disease has significant tremor, often with dementia after ataxia; Jetsman-Staple-Spike syndrome More than ataxia and other cerebellar damage, rare dementia; fatal familial insomnia is characterized by progressive intractable insomnia.
3. Laboratory inspection
The cavernous pathological changes of brain tissue and the immunological detection of PrPsc positive are of great significance in the diagnosis of this disease. Brain protein 14-3-3 and electroencephalogram PSWCs in cerebrospinal fluid have auxiliary diagnostic value, genetics of PRNP sequence base mutation Analysis can help diagnose the familial prion disease.
Differential diagnosis
Clinical should be differentiated from other types of prion diseases, extrapyramidal diseases, Alzheimer's disease, multi-infarct dementia, multifocal leukoencephalopathy, progressive supranuclear palsy, olive pons cerebellar atrophy, myoclonic epilepsy.
