Biomedical subjects

L D Ormerod

Publications and source records attributed to L D Ormerod.

61 records · Page 4Linked to original sources

PubMed1976

Pathophysiologic studies in human rabies.

Six patients with proved rabies were studied with a combination of clinical, physiologic and pathologic technics. Three were given a type of intensive care but died with evidence of respiratory failure. Although circulatory failure did not develop in any of the six patients, three had supraventricular arrhythmias: interstitial myocarditis was found in one of these and rabies virus was isolated from the myocardium of another. Inspiratory muscle spasm was the dominant clinical feature in all cases. This occurred as part of the hydrophobic response and followed stimulation of the upper respiratory tract and skin. Hydrophobia may represent an exaggerated respiratory tract irritant reflex with associated arousal. Later in the course of the disease, various patterns of periodic and ataxic breathing were observed. Widespread brain stem encephalitis was discovered at autopsy, with particular involvement of the neighborhood of the nucleus ambiguous in two of three patients examined. In one patient cerebral metabolism was grossly abnormal, with greatly reduced cerebral oxygen consumption suggesting irreversible brain damage. Respiratory and circulatory disturbances may well be immediate causes of death in patients with rabies, but the present studies reemphasize the severity of the encephalitis which remains the ultimate barrier to survival. In the developing countries in which rabies is still a major problem and in which the cost precludes intensive care, the clinical management of rabies can aim only to reduce suffering by heavy sedation.

Adolescent↗

PubMed1976

Bites by the night adder (Causus maculatus) and burrowing vipers (genus Atractaspis) in Nigeria.

Nineteen patients proven to have been bitten by the small African adders Causus maculatus, Atractapis dahomeyensis and A. microlepidota were studied in the Nigerian savanna region. One of the patients bitten by C. maculatus was drowsy, hypotensive and flaccid on admission but recovered without treatment. Mild or moderate local swelling, local lymphadenitis and mild fever were the only other features in this group. None of the patients bitten by Atractaspis had signs of systemic envenoming apart from moderate fever. Local blistering appeared in two cases but did not progress to necrosis. No patient showed any disturbance of blood coagulation, or evidence of spontaneous hemorrhage or of cranial nerve lesions. The small literature on the effects of Causus and Atractaspis venoms in man and in laboratory animals is reviewed. It appears that bites by these species are very unlikely to cause serious ill effects. A few deaths from Atractaspis bites have been reported, but the danger from these species has been exaggerated.

Adolescent↗

PubMed1976

Snake venom ophthalmia and blindness caused by the spitting cobra (Naja nigricollis) in Nigeria.

Venom entered the eyes of 9 patients spat at by the spitting cobra, Naja nigricollis. In 5 the only effect was a simple conjunctivitis but 4 had corneal ulceration, 1 developed anterior uveitis indicating absorption of venom in the anterior chamber, and 2 were permanently blinded. Treatment of this rare emergency is discussed: immediate irrigation of the eye with water, careful examination for corneal abrasion, and prevention of secondary infection are recommended. The value of local specific antivenom is unproven.

Adult↗

PubMed1976

Necrosis, haemorrhage and complement depletion following bites by the spitting cobra (Naja nigricollis).

The Spitting Cobra, Naja nigricollis, is widely and densely distributed in Africa. Fourteen patients with proven N. nigricollis bites, who were seen in the savanna region of Nigeria, did not exhibit the neurological signs, such as cranial nerve lesions and respiratory paralysis, expected following Elapid poisoning. All had local swelling, in eight cases involving the entire limb, and ten developed local tissue necrosis. Spontaneous haemorrhage was detected in three cases and was the probable cause of death in one of them; the other death in this series was unexplained. Haematological abnormalities included prolonged clot lysis anf failure of clot retraction due to a platelet defect. There was no specific deficit in clotting factors and a delayed rise in fibrin degradation products was attributed to extensive tissue damage at the site of the bit. Most patients showed depletion of complement component C3 and glycine-rich beta-glycoprotein (GBG), suggesting activation of the alternative pathway of complement fixation. There was evidence of hepatocellular damage in two out of six patients investigated. There was no evidence that specific polyvalent antivenoms, used in doses of up to 80 ml, prevented any of the effects of N. nigricollis venom. Clinical laboratory diagnosis is discussed. In the past many bites were wrongly classified as viper bites on the basis of clinical findings. Immunodiagnosis is a promising method for assessing the true importance of N. nigricollis bite in West Africa.

Adolescent↗

PubMed1975

Bites by puff-adder (Bitis arietans) in Nigeria, and value of antivenom.

Ten patients bitten by the puff-adder (Bitis arietans) were studied in the North of Nigeria. Six showed severe local signs, and four also had evidence of systemic envenoming, including spontaneous bleeding with thrombocytopenia, hypotension, and bradycardia. Two patients died after developing circulatory collapse and renal failure. Antivenom and intravenous fluid restored blood pressure in two hypotensive patients, and antivenom probably prevented the development of local necrosis in four others with massive local swelling. Victims of B arietans who have swelling of more than half the bitten limb or show signs of systemic envenoming should be given at least 80 ml of specific polyvalent antivenom and watched carefully for signs of circulatory collapse. Debridement of necrotic tissue may be necessary.

Adolescent↗

PubMed1974

Immunodiagnosis of snake bite.

Management of a patient with snake bite is influenced by the nature of the offending snake. Species diagnosis based on the patient's history and physical signs is often unreliable and the possibility of making a species diagnosis by immunological means has therefore been investigated. Wound aspirates, blister fluids, sera, and urine samples from patients with snake bite were examined for the presence of species-specific venoms using immunodiffusion. A positive species diagnosis was made in 40 out of 101 patients. Immunodiagnosis was especially successful in patients bitten by the puff adder, Bitis arietans, and the African spitting cobra, Naja nigricollis. A higher success rate could probably be achieved using more specific antisera and more sensitive assay techniques.

Animals↗

PubMedDate not supplied

An immunopathologic evaluation of lymph nodes from monkey and man with acquired immune deficiency syndrome and related conditions.

Morphology and immunostaining of lymph nodes taken from rhesus monkeys and man are compared. The monkeys were inoculated with biologic materials known to transmit simian acquired immune deficiency syndrome (SAIDS) and the human biopsies were obtained from homosexual men with persistent generalized lymphadenopathy syndrome or acquired immune deficiency syndrome (AIDS). The lymph nodes from monkey and man share common immunohistochemical features, ranging from exhuberant follicular hyperplasia to lymphocyte depletion stage. The follicular hyperplasia differed from reactive controls by the larger follicular size and disorganization within the follicular centers as well as an increase in the number of cells with the T suppressor/cytotoxic phenotype. The lymphocyte depletion stage showed a loss of reactive follicles and small T lymphocytes with a predominance of mature monocytes/macrophages. Most monkeys and humans with the lymphocyte depletion morphology fulfilled the case definitions for AIDS and SAIDS while those with follicular hyperplasia usually had 'prodromal' findings. The simian agent is associated with alterations in lymph node morphology and immunostaining which parallel the changes seen in spontaneous human cases supporting a similar pathogenesis for AIDS and SAIDS.

Acquired Immunodeficiency Syndrome↗