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Warrell DA. Bites by dark green pit vipers in Bangkok. Am J Trop Med Hyg 1990; 42:623-4. [PMID: 2372090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Pukrittayakamee S, Nontprasert A, White NJ, Warrell DA, Bunnag D. Characterization of a monoclonal antibody that neutralizes the hyaluronidase activity of Russell's viper venom. THE SOUTHEAST ASIAN JOURNAL OF TROPICAL MEDICINE AND PUBLIC HEALTH 1990; 21:231-7. [PMID: 2237592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Three monoclonal antibodies (WPN1, WPN2 and WPN3) raised against a partially purified fraction of Russell's viper venom (RVV) were characterized. All three monoclonal antibodies reacted with crude RVV when tested by ELISA, but only two (WPN1, WPN2) neutralized its hyaluronidase activity. WPN1 was the more potent and was effective at an antigen: antibody ratio of 1:3. Furthermore, WPN1 was shown to recognize only the 14,000 MW component of crude RVV. This has been identified in a previous study to be hyaluronidase. This antibody was also found to recognize some components of Calloselasma rhodostoma venom which also possesses potent hyaluronidase activity. The potential therapeutic role of antibodies that neutralize the hyaluronidase component of snake venoms should be investigated further.
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Looareesuwan S, Phillips RE, Karbwang J, White NJ, Flegg PJ, Warrell DA. Plasmodium falciparum hyperparasitaemia: use of exchange transfusion in seven patients and a review of the literature. THE QUARTERLY JOURNAL OF MEDICINE 1990; 75:471-81. [PMID: 2201995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
During the last 15 years, at least 35 patients with severe falciparum malaria or babesiosis have recovered following treatment by exchange of up to 10 l of blood. In a patient treated in Manchester, a parasitaemia of 2.10 X 10(6) microliters (42 per cent) was virtually eliminated over eight hours by a 3.5 litre exchange blood transfusion. However, the equipment and amounts of compatible blood required for total exchange are rarely available in areas endemic for malaria and the risks of the procedure, including transfusion-related infections, are high. Partial exchange transfusion with one to two litres of blood carried out over two to seven hours, reduced Plasmodium falciparum parasitaemias of 0.33-1.48 X 10(6)/microliters (13-38 per cent) to 0.11-0.81 X 10(6) (4-17 per cent) in six Thai patients who were receiving intravenous quinine. The reduction in parasitaemia ranged from 0.13-0.67 X 10(6) microliters (9-12 per cent) within six hours. During the same period, parasitaemia in 13 patients with cerebral malaria treated with chemotherapy alone showed little reduction from initial levels of 0.20-1.74 X 10(6)/microliters (11-42 per cent). One of the patients who were treated with exchange transfusion died with intractable hypotension before the procedure could be completed and two others developed oliguric renal failure which was controlled by peritoneal dialysis. Partial exchange transfusion is a promising and practical alternative to total exchange where facilities are limited. It deserves further assessment in the rural tropics.
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154
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Ho M, Silamut K, White NJ, Karbwang J, Looareesuwan S, Phillips RE, Warrell DA. Pharmacokinetics of three commercial antivenoms in patients envenomed by the Malayan pit viper, Calloselasma rhodostoma, in Thailand. Am J Trop Med Hyg 1990; 42:260-6. [PMID: 2316795 DOI: 10.4269/ajtmh.1990.42.260] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The pharmacokinetics of 3 monospecific antivenoms were compared in patients envenomed by the Malayan pit viper, Calloselasma rhodostoma. There was a biphasic decline in serum concentrations following intravenous administration. The initial rapid decline was attributable to the formation of venom-antivenom complexes, as the fall in antivenom during this phase was positively correlated with the initial venom concentration (P = 0.045). The total apparent volume of distribution for each antivenom was 1.5-3 times larger than that of the central compartment, which suggests some tissue distribution in addition to complex formation. This was marked for antivenom from the Government Pharmaceutical Organization of Thailand which contained mostly F(ab)2 fragments. The terminal elimination half time was shorter for Twyford antivenom of caprine origin. Systemic clearance was lower for Thai Red Cross antivenom. In 8 of the 26 patients who experienced recurrence of non-clotting blood after initial response to antivenom, serial measurements of plasma venom and antivenom concentrations revealed that recurrence of venom antigenemia and non-clotting blood bore no direct relation to the elimination half-life of the antivenom used, but non-clotting blood recurred when serum antivenom levels fell below 10-20% of the total given. There is no substitute for close monitoring of envenomed patients so that indications for further antivenom can be detected promptly.
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155
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Theakston RD, Phillips RE, Warrell DA, Galagedera Y, Abeysekera DT, Dissanayaka P, de Silva A, Aloysius DJ. Envenoming by the common krait (Bungarus caeruleus) and Sri Lankan cobra (Naja naja naja): efficacy and complications of therapy with Haffkine antivenom. Trans R Soc Trop Med Hyg 1990; 84:301-8. [PMID: 2389328 DOI: 10.1016/0035-9203(90)90297-r] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In Anuradhapura, Sri Lanka, 5 patients proved to have been bitten by common kraits (Bungarus caeruelus) and 2 by Sri Lankan cobras (Naja naja naja) were investigated. In all the cases of krait bite the patients were bitten while they were asleep: local signs were negligible but 4 developed symptoms of systemic envenoming including paralysis, muscle pain and tenderness and abdominal pain. Mild myoglobinaemia was found in one case. Of the 2 patients bitten by cobras, one developed severe local swelling which progressed to necrosis and the other local swelling and respiratory paralysis. Response to polyspecific antivenom (Haffkine, India) was neither rapid nor convincing. Venom antigenaemia became undetectable within 2 h of the start of antivenom treatment, but recurred 25 and 65 h later in 2 cases. Among a group of 27 patients treated with this antivenom (including 21 bitten by Russell's vipers), the incidence of early anaphylactic and pyrogenic reactions was high at 52% and 65% respectively. Anticholinesterase did not improve paralysis in 2 patients bitten by kraits. The respiratory failure in 2 patients was successfully treated by mechanical ventilation for 8 and 30 h. These observations confirm the importance of neurotoxic symptoms following bites by these species but also suggest a contributory role of generalized rhabdomyolysis in krait victims and emphasize the problem of severe local tissue necrosis in cobra victims. There is a need for safer and more potent antivenoms for use in Sri Lanka.
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Warrell DA. Snake venoms in science and clinical medicine. 1. Russell's viper: biology, venom and treatment of bites. Trans R Soc Trop Med Hyg 1989; 83:732-40. [PMID: 2533418 DOI: 10.1016/0035-9203(89)90311-8] [Citation(s) in RCA: 150] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Russell's viper, Vipera russelli (Shaw), is distributed erratically in 10 south Asian countries and is a leading cause of fatal snake bite in Pakistan, India, Bangladesh, Sri Lanka, Burma and Thailand. In Burma it has been the 5th most important cause of death. Its venom is of great interest to laboratory scientists and clinicians. The precoagulant activity of the venom was used by Macfarlane and others to elucidate the human clotting cascade. Up to 70% of the protein content is phospholipase A2, present in the form of at least 7 isoenzymes. Possible clinical effects of the enzyme include haemolysis, rhabdomyolysis, pre-synaptic neurotoxicity, vasodilatation and shock, release of endogenous autacoids and interaction with monoamine receptors. Russell's viper bite is an occupational hazard of rice farmers throughout its geographical range. Defibrination, spontaneous haemorrhage, shock and renal failure develop with frightening rapidity. In several countries, Russell's viper bite is the commonest cause of acute renal failure. There is a fascinating geographical variation in the clinical manifestations, doubtless reflecting differences in venom composition. Conjunctival oedema is unique to Burma, acute pituitary infarction to Burma and south India, and rhabdomyolysis and neurotoxicity to Sri Lanka and south India. Treatment with potent specific antivenom rapidly controls bleeding and clotting disorders, but may not reverse nephrotoxicity and shock. Causes of death include shock, pituitary and intracranial haemorrhage, massive gastrointestinal haemorrhage and acute tubular necrosis or bilateral renal cortical necrosis. The paddy farmer and the Russell's viper coexist in fragile symbiosis. The snake controls rodent pests but inevitably interacts with man, often with mutually disastrous results.
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158
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Warrell DA. Cerebral malaria. THE QUARTERLY JOURNAL OF MEDICINE 1989; 71:369-71. [PMID: 2690175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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159
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Molyneux ME, Looareesuwan S, Menzies IS, Grainger SL, Phillips RE, Wattanagoon Y, Thompson RP, Warrell DA. Reduced hepatic blood flow and intestinal malabsorption in severe falciparum malaria. Am J Trop Med Hyg 1989; 40:470-6. [PMID: 2729505 DOI: 10.4269/ajtmh.1989.40.470] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We have studied intestinal function and liver blood flow in Thai adults with complicated and uncomplicated falciparum malaria. The absorption of 3 orally administered test sugars, D-xylose, 3-O-methyl-D-glucose, and L-rhamnose, was greatly reduced in complicated malaria, while the lactulose/rhamnose absorption ratio was significantly increased. Hepatic blood flow was concomitantly reduced in severe malaria. These deviations reverted to normal in convalescence. Neither sugar absorption nor liver blood flow was reduced in uncomplicated falciparum malaria.
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160
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Ratcliffe PJ, Pukrittayakamee S, Ledingham JG, Warrell DA. Direct nephrotoxicity of Russell's viper venom demonstrated in the isolated perfused rat kidney. Am J Trop Med Hyg 1989; 40:312-9. [PMID: 2929855 DOI: 10.4269/ajtmh.1989.40.312] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Envenoming by Russell's Viper (Vipera russelli) is an important cause of acute renal failure. The mechanism of renal damage is unresolved. It is difficult to obtain evidence of a direct nephrotoxic action because of the coincidental disturbance to the systemic circulation. We studied the action of Russell's Viper venom on the function of the isolated perfused rat kidney. Direct nephrotoxic action was indicated by a dose dependent decrease in inulin clearance and an increase in fractional excretion of sodium seen at venom concentrations down to 50 ng/ml, a concentration likely to be achieved in the human circulation after envenoming. The isolated perfused kidney was also used to assess the efficiency of antivenom and for a comparison with snake venoms from the Thai cobra (Naja kauothia) and the Nigerian Saw-Scaled Viper (Echis ocellatus).
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161
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Than-Than, Francis N, Tin-Nu-Swe, Myint-Lwin, Tun-Pe, Soe-Soe, Maung-Maung-Oo, Phillips RE, Warrell DA. Contribution of focal haemorrhage and microvascular fibrin deposition to fatal envenoming by Russell's viper (Vipera russelli siamensis) in Burma. Acta Trop 1989; 46:23-38. [PMID: 2566258 DOI: 10.1016/0001-706x(89)90013-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In Burma, clinicopathological studies were carried out in three young farmers who died 15, 52 and 36 h after being bitten by Russell's vipers. Clinical features included local swelling, spontaneous systemic bleeding, defibrination, shock, cardiac arrhythmia, hypoglycaemia, coma and oliguria. On admission to hospital, 15, 48 and 21 h after the bites, serum venom antigen concentrations ranged from 50 to 130 ng/ml. Autopsies revealed widespread congestion and bleeding in the lungs, gastrointestinal and renal tracts, adrenals, heart, brain and anterior pituitary. There was histopathological evidence of focal haemorrhage and fibrin deposition at the site of the bite and in the pituitary, lungs and kidneys and acute tubular necrosis. Deposition of fibrin microthrombi results from the action of venom procoagulants. Shock was attributed to increased capillary permeability, revealed clinically by conjunctival oedema. Acute pituitary/adrenal failure in one case was explained by fibrin deposition and haemorrhage in the anterior pituitary--resembling Sheehan's syndrome. Acute tubular necrosis resulted from ischaemia caused by fibrin deposition and to prerenal factors. An intractable cardiac tachyarrhythmia may have been caused by subendocardial and myocardial haemorrhages.
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162
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Warrell DA. Treatment of severe malaria. J R Soc Med 1989; 82 Suppl 17:44-50; discussion 50-1. [PMID: 2693726 PMCID: PMC1291940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In the treatment of severe Plasmodium falciparum infection antimalarial drugs should, ideally, be given by controlled rate intravenous infusion until the patient is able to swallow tablets. In cases where infection has been acquired in a chloroquine resistant area, and where it has broken through chloroquine prophylaxis or where the geographical origin or species are uncertain, quinine is the treatment of choice. When access to parenteral quinine is likely to be delayed, parenteral quinidine is an effective alternative. A loading dose of quinine is recommended in order to achieve therapeutic plasma concentrations as quickly as possible. In the case of chloroquine sensitive P. falciparum infection, chloroquine, which can be given safely by slow intravenous infusion, may be more rapidly effective and has fewer toxic effects than quinine. There is limited experience with parenteral administration of pyrimethamine sulphonamide combinations such as Fansidar, and resistance to these drugs has developed in South East Asia and elsewhere. Mefloquine and halofantrine cannot be given parenterally. Qinghaosu derivatives are not readily available and have not been adequately tested outside China. Supportive treatment includes the prevention or early detection and treatment of complications, strict attention to fluid balance, provision of adequate nursing for unconscious patients and avoidance of harmful ancillary treatments. Anaemia is inevitable and out of proportion to detectable parasitaemia. Hypotension and shock ('algid malaria') are often attributable to secondary gram-negative septicaemia requiring appropriate antimicrobial therapy and haemodynamic resuscitation. Many patients with severe falciparum malaria are hypovolaemic on admission to hospital and require cautious fluid replacement. Failure to rehydrate these patients may lead to circulatory collapse, lactic acidosis, renal failure and severe hyponatraemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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Looareesuwan S, Viravan C, Warrell DA. Factors contributing to fatal snake bite in the rural tropics: analysis of 46 cases in Thailand. Trans R Soc Trop Med Hyg 1988; 82:930-4. [PMID: 3257001 DOI: 10.1016/0035-9203(88)90046-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Records of 46 cases of fatal bites by identified snakes from 15 provincial hospitals throughout Thailand contained sufficient information for detailed analysis. Bungarus candidus and Calloselasma rhodostoma were each responsible for 13 deaths, Naja kaouthia for 12, Vipera russelli for 7 and B. fasciatus for one. Major causes of death among elapid victims were respiratory failure (26) and complications of prolonged mechanical ventilation (10), and among viper victims shock (12), intracranial haemorrhage (9), complications of local wound necrosis (7) including tetanus (2), and renal failure (2). Factors contributing to fatal outcome included inadequate dose of antivenom (15 cases), misidentification of the snake leading to use of the wrong antivenom (12), problems associated with mechanical ventilation (10), and delayed arrival in hospital after traditional (herbal) treatment (10). Similar problems have been identified in other tropical countries. Education of medical staff and the patient population at highest risk could reduce snake bite mortality.
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Warrell DA, Warrell MJ. Human rabies and its prevention: an overview. REVIEWS OF INFECTIOUS DISEASES 1988; 10 Suppl 4:S726-31. [PMID: 3060958 DOI: 10.1093/clinids/10.supplement_4.s726] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Human rabies is underreported, but it clearly is still a frequent medical problem that is virtually confined to tropical countries. Rabies encephalitis remains essentially incurable, and most patients die at home, their terrible symptoms unpalliated by sedatives or analgesics. Recent attempts to cure rabies in well-equipped intensive care units have failed, a situation reemphasizing the importance of preventive measures. The great advances that have been made in understanding the rabies virus and the associated improvements in rabies vaccines have had little or no impact in the tropical endemic zone. Most patients who have been exposed to rabies are still given nervous tissue vaccines for postexposure prophylaxis. An urgent priority is the development of a regimen using tissue culture vaccine that is sufficiently economical to replace nervous tissue vaccine. This has been achieved in China with primary hamster kidney cell vaccine.
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Warrell DA, White NJ, Veall N, Looareesuwan S, Chanthavanich P, Phillips RE, Karbwang J, Pongpaew P, Krishna S. Cerebral anaerobic glycolysis and reduced cerebral oxygen transport in human cerebral malaria. Lancet 1988; 2:534-8. [PMID: 2900921 DOI: 10.1016/s0140-6736(88)92658-x] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In 12 patients comatose with cerebral malaria, cerebral blood flow was 52.2 (SE 4.0) ml/100 g per min, within the reported range for healthy controls, but cerebral vascular resistance was raised at 1.66 (0.19) mm Hg/ml per 100 g per min. Cerebral oxygen consumption (1.90 [0.23] ml/100 g per min), and cerebral arteriovenous oxygen content difference (3.5 [0.43] ml/dl) were subnormal, while cerebral venous pO2 (5.7 [0.2] kpA) was raised. After recovery of consciousness there were significant decreases in arterial lactate concentration (2.44 [0.45] to 1.19 [0.45] mumol/l) and cerebral lactate production (17.4 [7.9] to 5.6 [1.1] mmol/100 g per minute). These results provide evidence of cerebral anaerobic glycolysis associated with inadequate oxygen delivery to the brain consistent with either inhibition of cerebral oxidative metabolism or the microcirculatory obstruction envisaged in the "mechanical" hypothesis for cerebral malaria.
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166
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Phillips RE, Theakston RD, Warrell DA, Galigedara Y, Abeysekera DT, Dissanayaka P, Hutton RA, Aloysius DJ. Paralysis, rhabdomyolysis and haemolysis caused by bites of Russell's viper (Vipera russelli pulchella) in Sri Lanka: failure of Indian (Haffkine) antivenom. THE QUARTERLY JOURNAL OF MEDICINE 1988; 68:691-715. [PMID: 3256900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In Sri Lanka, Russell's viper, Vipera russelli pulchella, kills more people than any other species of snake. At Anuradhapura in the dry central zone of the island we studied 23 patients with systemic envenoming after proven bites. Seventy-three per cent had swelling at the bite site. Neurotoxicity was the commonest sign of systemic envenoming: 82 per cent had external ophthalmoplegia and 77 per cent had ptosis. Incoagulable blood was found in 59 per cent but only 36 per cent had spontaneous bleeding. Other signs included generalized muscle tenderness (32 per cent), black urine (27 per cent) and persistent oliguria (9 per cent). Laboratory studies showed evidence of a severe clotting disorder: fibrinogen was often depleted as were factors V and X. Fibrin degradation products, including cross-linked moieties, were grossly elevated, clear evidence for enhanced fibrinolysis. Intravascular haemolysis, unrelated to G6PD deficiency, was often present. Myoglobin was detected in the plasma of all 19 patients tested (range 100- greater than 8000 ng/ml) and in the urine in 14 of 18 patients (110- greater than 16,000 ng/ml). Venom antigen (16.5-702 ng/ml) was detected by specific ELISA in the serum of all patients. Its concentration fell with the administration of 50-200 ml of Haffkine polyspecific antivenom raised against Indian venoms. Complete permanent clearance of venom antigen from the circulation was seen in only one of 21 patients who were followed until discharge. Blood coagulability was restored between one and 25 h (mean 8.8) after the first dose of antivenom in the 12 surviving patients whose clotting defect could be followed; no dramatic reversal of neuromyotoxic signs was seen. Haffkine antivenom thus has limited efficacy against systemic poisoning by Russell's viper in Sri Lanka.
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167
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Hutton RA, Phillips RE, Warrell DA. Haemostatic disturbances in patients bitten by Russell's viper (Vipera russelli siamensis) in Burma. Br J Haematol 1988; 69:513-20. [PMID: 3408687 DOI: 10.1111/j.1365-2141.1988.tb02408.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Patients who are severely envenomed by Russell's viper develop DIC which is frequently associated with spontaneous bleeding and incoagulable blood. These haemostatic disturbances may be responsible for death or organ/tissue damage both through haemorrhage and microvascular occlusion by fibrin thrombi. The most striking laboratory features of the coagulopathy developing after Russell's viper bite in the 42 patients studied were depletion of fibrinogen (mean 0.09 g/l, range 0-0.6), factor V (6.5 u/dl, range 0-17), factor X (35 u/dl, range 1-85), factor XIIIa (57 u/dl, range 15-82), plasminogen (61 u/dl, range 10-92), antiplasmin (36 u/dl, range 14-62). Protein C (49 u/dl, range 15-100) and platelets (104 x 10(9)/l, range 25-197). Intense fibrinolytic activity was detected in all cases with marked elevation of FDPs (1614 micrograms/ml, range 350-3000), a large proportion of which were cross-linked (1058 micrograms/ml, range 38-3000). The monospecific Burmese antivenom appeared to be very effective in neutralizing the venom procoagulants and in restoring blood coagulability. Moreover, the unexpectedly normal level of AT III provides a theoretical basis for the use of heparin to enhance the inactivation of those serine proteases present before antivenom administration.
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White NJ, Looareesuwan S, Phillips RE, Chanthavanich P, Warrell DA. Single dose phenobarbitone prevents convulsions in cerebral malaria. Lancet 1988; 2:64-6. [PMID: 2898696 DOI: 10.1016/s0140-6736(88)90002-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
48 patients over 6 years of age with strictly defined cerebral malaria were randomised to receive either a single intramuscular injection of phenobarbitone (3.5 mg/kg) or placebo in a double-blind, placebo-controlled study. Phenobarbitone significantly reduced the incidence of subsequent convulsions from 54% to 12.5%, without adverse effects. A single intramuscular injection of phenobarbitone is a simple, cheap, and effective method for prevention of convulsions in cerebral malaria.
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Davis TM, White NJ, Looareesuwan S, Silamut K, Warrell DA. Quinine pharmacokinetics in cerebral malaria: predicted plasma concentrations after rapid intravenous loading using a two-compartment model. Trans R Soc Trop Med Hyg 1988; 82:542-7. [PMID: 3256106 DOI: 10.1016/0035-9203(88)90498-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
To investigate the toxic potential of rapid intravenous quinine administration in severe malaria, the pharmacokinetic properties of low-dose quinine dihydrochloride injection (4 mg/kg body weight, equivalent to 3.3 mg base/kg) followed one hour later by infusion of 16 mg/kg over 3 h were studied in 7 patients with cerebral malaria. Plasma quinine concentrations closely followed a bi-exponential decline. Both the volumes of the central compartment (mean +/- SD: 0.17 +/- 0.10 litre/kg) and total volumes of distribution (0.74 +/- 0.30 litre/kg) were significantly smaller than those previously reported for healthy subjects. Based on the derived pharmacokinetic parameters, predicted plasma quinine concentrations following intravenous injection of the standard therapeutic dose (10 mg salt/kg) over 10-20 min are potentially toxic in severe malaria. Further reductions in administration time would produce disproportionately higher plasma quinine concentrations, especially as the distribution half-time (2.3 +/- 3.2 min) is approached. A theoretical regimen designed to achieve therapeutic, non-toxic plasma quinine concentrations promptly would be 7.0 mg quinine dihydrochloride/kg over 30 min. A subsequent maintenance infusion of 10 mg/kg over 4 h would allow for drug elimination and acute changes in pharmacokinetic parameters due to resuscitation and rehydration.
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170
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Looareesuwan S, Phillips RE, Edwards G, Rodick CL, Chanthavanich P, Supanaranond W, Warrell DA. Mepacrine accumulation during treatment of chloroquine-resistant falciparum malaria. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1988; 82:107-12. [PMID: 3052330 DOI: 10.1080/00034983.1988.11812216] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Oral mepacrine dihydrochloride, 200 mg (158 mg of the base) six-hourly for five doses followed by 100 mg (79 mg of the base) eight-hourly for six days (half dosage for those less than or equal to 50 kg) was given to 21 patients with high-grade chloroquine-resistant falciparum malaria in eastern Thailand. Fifteen patients (71%) had a clinical response [fever clearance time of 81 +/- 35 hours (mean +/- S.D.)] and 13 (62%) had complete clearance of parasitaemia (clearance time 92 +/- 42 hours). Two patients were cured, but 11 patients returned with recurrent parasitaemia between 11 and 40 days after starting treatment. Five patients had an R2 response and three had an R3 response. Mepacrine retains some activity against chloroquine-resistant falciparum malaria but it cannot be recommended for use in Thailand. The doses used, which are those also recommended for giardiasis, led to progressive and potentially toxic mepacrine accumulation. Further evaluation of regimens which produce safer plasma concentration profiles is needed.
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171
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Singh B, Ho M, Looareesuwan S, Mathai E, Warrell DA, Hommel M. Plasmodium falciparum: inhibition/reversal of cytoadherence of Thai isolates to melanoma cells by local immune sera. Clin Exp Immunol 1988; 72:145-50. [PMID: 3293849 PMCID: PMC1541488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The effect of sera on the cytoadherence in vitro of Plasmodium falciparum-infected erythrocytes to melanoma cells was examined. Sera from 19 healthy individuals living in endemic malarious areas in Thailand and 24 patients with P. falciparum malaria were tested against four local P. falciparum isolates. Out of 57 sera examined, 12 (21%) showed significant inhibition (greater than 50%) of cytoadherence for at least one isolate. Anti-malarial IgG antibody titres were determined for all 57 sera and although 11 of the 12 inhibitory sera had relatively high titres, 36 out of 47 sera with similarly high titres showed no significant inhibitory activity. Convalescent sera were no more effective than corresponding acute sera in inhibiting the cytoadherence of erythrocytes infected with any of the four heterologous isolates examined. Sera which significantly inhibited cytoadherence were also capable of reversing cytoadherence, and pooled plasma, from healthy individuals living in malarious areas, was effective in significantly reversing the in vitro cytoadherence of all the five parasite isolates examined. The results confirm the antibody mediated strain-specific nature of the inhibition of cytoadherence and stress the difficulty in selecting immune sera potentially useful for the immunotherapy of cerebral malaria patients in Thailand.
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Edwards G, Looareesuwan S, Davies AJ, Wattanagoon Y, Phillips RE, Warrell DA. Pharmacokinetics of chloroquine in Thais: plasma and red-cell concentrations following an intravenous infusion to healthy subjects and patients with Plasmodium vivax malaria. Br J Clin Pharmacol 1988; 25:477-85. [PMID: 3289601 PMCID: PMC1387810 DOI: 10.1111/j.1365-2125.1988.tb03332.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
1. Chloroquine diphosphate (15 mg base kg-1) was given by constant rate intravenous infusion to two groups of Thai subjects. Eleven were patients with malaria (10 with Plasmodium vivax and one case with Plasmodium malariae) and 10 were healthy normal volunteers. 2. Plasma and packed red-cell concentrations of chloroquine, electrocardiographic intervals, arterial blood pressure and pulse were measured at frequent intervals. 3. Peak plasma concentrations at the end of the infusion ranged from 979 to 2,900 ng ml-1 in the malaria patients. In the group of healthy subjects the range was 550-2,200 ng ml-1. Values for terminal elimination rate constant, (lambda z) plasma clearance (CL), initial volume of distribution (V1) and volume of distribution at steady state (Vss) were calculated. For the healthy subjects, mean estimates of these parameters were lambda z = 0.062 +/- 0.030 day-1, CL = 597 +/- 238 ml min-1, V1 = 0.66 +/- 0.71 l kg-1 and Vss = 132 +/- 50 l.kg-1 For the group of malaria patients, the corresponding values were lambda z = 0.055 +/- 0.032 day-1, CL = 535 +/- 246 ml min-1, V1 = 0.74 +/- 0.75 l kg-1 and Vss = 136 +/- 64 l kg-1 There was no statistically significant difference in the estimates for any parameter between groups (P less than or equal to 0.05). 4. Chloroquine concentrations in packed red blood cells consistently exceeded those in plasma and showed no consistent change with time throughout the period of study in either group. The median value for the red cell to plasma ratio was between 3 and 4 in each group.(ABSTRACT TRUNCATED AT 250 WORDS)
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Warrell MJ, Looareesuwan S, Manatsathit S, White NJ, Phuapradit P, Vejjajiva A, Hoke CH, Burke DS, Warrell DA. Rapid diagnosis of rabies and post-vaccinal encephalitides. Clin Exp Immunol 1988; 71:229-34. [PMID: 2894908 PMCID: PMC1541427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In an attempt to establish the diagnoses of rabies post-vaccinal encephalitis (PVE) and early rabies encephalitis, paired serum and CSF levels of rabies neutralizing antibody (Rab) and rabies specific-IgM (RIgM) were compared in 12 PVE, 10 rabies and five control patients with similar presenting clinical features. Rapid methods of rabies antigen detection were evaluated in 17 patients. All 12 PVE patients had Rab in their serum and in eight it was also present in the CSF. These same eight had RIgM in the serum, and in seven also in the CSF. The CSF antibodies may have originated in the plasma since six patients had a high albumin quotient indicating leakage across the blood-brain barrier. Among the rabies patients, only the two vaccinated ones had serum Rab; this was also detected in the CSF of one and RIgM was in the CSF of the other. A raised IgG Index, indicating intrathecal synthesis of IgG was seen in five of 12 PVE patients. This did not correlate with the presence of CSF rabies antibody, suggesting production of antibody to other vaccine antigens of neural origin. The diagnosis of rabies encephalitis in life was made by antigen detection in a skin biopsy. No false positive results occurred and the method was as efficient as immunofluorescence of a post-mortem brain biopsy.
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174
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Pukrittayakamee S, Warrell DA, Desakorn V, McMichael AJ, White NJ, Bunnag D. The hyaluronidase activities of some Southeast Asian snake venoms. Toxicon 1988; 26:629-37. [PMID: 3176052 DOI: 10.1016/0041-0101(88)90245-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The hyaluronidase activities of venoms of snakes indigenous to Southeast Asia were investigated. With the exception of the venom of the Malayan krait Bungarus candidus, the elapid venoms had either little or no hyaluronidase activities, whereas the viperid venoms possessed considerable activity. A component of Russell's viper venom with hyaluronidase activities had a mol. wt of approximately 14,000. Neither MP4, a monoclonal antibody raised against the purified Russell's viper venom hyaluronidase toxin, nor a monospecific polyclonal antivenom neutralized the hyaluronidase activities of this purified hyaluronidase component of crude Russell's viper venom. The Russell's viper venom hyaluronidase activities was labile on heating and storage. The significance of these observations to envenomation and antivenom production is discussed.
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175
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Webster HK, Ho M, Looareesuwan S, Pavanand K, Wattanagoon Y, Warrell DA, Hockmeyer WT. Lymphocyte responsiveness to a candidate malaria sporozoite vaccine (R32tet32) of individuals with naturally acquired Plasmodium falciparum malaria. Am J Trop Med Hyg 1988; 38:37-41. [PMID: 3277463 DOI: 10.4269/ajtmh.1988.38.37] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Lymphocyte proliferative responses to the candidate malaria sporozoite vaccine antigen R32tet32 were evaluated in 29 patients with acute Plasmodium falciparum malaria, 20 convalescent patients, 11 nonimmune individuals, and 22 healthy residents of two endemic malarious areas in Thailand. The results indicate that 14 of 20 (70%) convalescent patients and 14 of 22 (64%) residents of endemic areas responded to the R32tet32 antigen. However, only 8 of 29 (28%) patients with acute P. falciparum malaria responded. When 4 of the convalescent patients who remained in a malaria-free area were restudied 5-10 months after the acute infection, they were either not responsive or their responses had greatly diminished. These findings show that sensitization to R32tet32 occurs following a natural P. falciparum infection, but the cellular immune response to sporozoite antigens may be short-lived and may be suppressed during acute P. falciparum malaria.
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176
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Suntharasamai P, Warrell MJ, Viravan C, Chanthavanich P, Looareesuwan S, Supapochana A, Supanaranond JK, Chittamas S, Bijok U, Warrell DA. Purified chick embryo cell rabies vaccine: economical multisite intradermal regimen for post-exposure prophylaxis. Epidemiol Infect 1987; 99:755-65. [PMID: 3428378 PMCID: PMC2249234 DOI: 10.1017/s0950268800066619] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The standard six-dose intramuscular (i.m.) rabies post-exposure vaccine regimen using a new purified chick embryo cell (PCEC) vaccine was compared with two economical multisite intradermal (i.d.) PCEC regimens, a multisite i.m. PCEC schedule and a subcutaneous regimen using a suckling mouse brain (SMB) rabies vaccine manufactured in Thailand. The neutralizing antibody results for the four-site and eight-site i.d. and the standard i.m. PCEC regimens were similar over 3 months. A three-site i.m. PCEC regimen had no advantage. The SMB vaccine gave the lowest antibody levels. Human rabies immune globulin therapy significantly increased the GMT of all groups on day 7, unlike equine antirabies serum (EARS). Both antisera suppressed antibody responses to PCEC on days 14 and 28. Three generalized reactions probably related to EARS were the only serious side effects. An eight-site i.d. PCEC vaccine regimen proved as immunogenic as the routine i.m. schedule and, if implemented as post-exposure prophylaxis, would be the cheapest widely available tissue culture vaccine regimen. The protective efficiency should now be tested in patients bitten by rabid animals.
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177
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Looareesuwan S, Merry AH, Phillips RE, Pleehachinda R, Wattanagoon Y, Ho M, Charoenlarp P, Warrell DA, Weatherall DJ. Reduced erythrocyte survival following clearance of malarial parasitaemia in Thai patients. Br J Haematol 1987; 67:473-8. [PMID: 3322362 DOI: 10.1111/j.1365-2141.1987.tb06171.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Erythrocyte survival times were measured in healthy Thai controls and in patients following clearance of asexual P. falciparum or P. vivax parasitaemia. In five controls the mean cell life (MCL) of compatible donor erythrocytes was 89.6 d (mean range 73-101 d) compared with a mean MCL of 56.8 d (range 30-66 d) for autologous erythrocytes in 12 falciparum patients. In one of these patients the survival curve was biphasic with a rapid loss of some labelled cells. The survival of compatible donor erythrocytes was also studied in 10 patients and two types of survival curve could be distinguished. In five patients the cells had a mean MCL of 64.4 d (range 42-90 d). In the others survival curves were curvilinear, suggesting a complex mechanism of cell clearance or the presence of more than one cell population. There was initially a more rapid rate of destruction. In P. vivax malaria the MCL of autologous erythrocytes in seven patients was a mean of 67.2 d (range 34-74 d) and that of compatible donor cells in six patients was 66.8 d (range 54-76 d). In all except one of these patients both autologous and donor cell survival curves could be fitted to straight lines. No increase in cell-bound IgG or C3 was evident in 12 patients tested. The differences between the mean MCL in all the groups of patients and the controls were statistically significant at the 5% level. This indicates an increased rate of erythrocyte destruction following clearance of P. falciparum or P. vivax parasites which is not antibody or complement mediated. The mechanism is unknown, but appears to be extrinsic to the erythrocytes themselves and may result from nonspecific activation of the reticuloendothelial function associated with the parasitic infection.
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178
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Phillips RE, Warrell DA, Moore RA, Burke CW. Acute and chronic pituitary failure resembling Sheehan's syndrome following bites by Russell's viper in Burma. Lancet 1987; 2:763-7. [PMID: 2888987 DOI: 10.1016/s0140-6736(87)92500-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Pituitary function was investigated in 9 patients in shock after Russell's viper bites and in 24 individuals who had been severely envenomed 2 weeks to 24 years previously. 3 out of 9 patients had hypoglycaemia and inappropriately low serum cortisol, plasma growth hormone, and plasma prolactin concentrations. 4 who died had pituitary haemorrhage and 1 had adrenal haemorrhage as well. Of the 24 who had apparently recovered from bites, 7 had clinical features of hypopituitarism and no response in plasma growth hormone or prolactin concentrations to symptom-producing insulin-induced hypoglycaemia. 4 of these 7 had a sluggish serum cortisol response to 'Synacthen Depot' and 5 had an abnormal cortisol response to hypoglycaemia. 4 men with symptoms who were tested had low serum testosterone concentrations; serum thyroxine was also low in these men but not in 2 women with menstrual disturbances and impaired insulin responses. Of the 17 individuals without clinical evidence of endocrine disease, 4 had pituitary hormonal abnormalities. Russell's viper envenoming may thus produce a disorder resembling Sheehan's syndrome.
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Looareesuwan S, Ho M, Wattanagoon Y, White NJ, Warrell DA, Bunnag D, Harinasuta T, Wyler DJ. Dynamic alteration in splenic function during acute falciparum malaria. N Engl J Med 1987; 317:675-9. [PMID: 3306376 DOI: 10.1056/nejm198709103171105] [Citation(s) in RCA: 131] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Plasmodium-infected erythrocytes lose their normal deformability and become susceptible to splenic filtration. In animal models, this is one mechanism of antimalarial defense. To assess the effect of acute falciparum malaria on splenic filtration, we measured the clearance of heated 51Cr-labeled autologous erythrocytes in 25 patients with acute falciparum malaria and in 10 uninfected controls. Two groups of patients could be distinguished. Sixteen patients had splenomegaly, markedly accelerated clearance of the labeled erythrocytes (clearance half-time, 8.4 +/- 4.4 minutes [mean +/- SD] vs. 62.5 +/- 36.5 minutes in controls; P less than 0.001), and a lower mean hematocrit than did the patients without splenomegaly (P less than 0.001). In the nine patients without splenomegaly, clearance was normal. After institution of antimalarial chemotherapy, however, the clearance in this group accelerated to supernormal rates similar to those in the patients with splenomegaly, but without the development of detectable splenomegaly. Clearance was not significantly altered by treatment in the group with splenomegaly. Six weeks later, normal clearance rates were reestablished in most patients in both groups. We conclude that splenic clearance of labeled erythrocytes is enhanced in patients with malaria if splenomegaly is present and is enhanced only after treatment if splenomegaly is absent. Whether this enhanced splenic function applies to parasite-infected erythrocytes in patients with malaria and has any clinical benefit will require further studies.
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180
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Wickramasinghe SN, Phillips RE, Looareesuwan S, Warrell DA, Hughes M. The bone marrow in human cerebral malaria: parasite sequestration within sinusoids. Br J Haematol 1987; 66:295-306. [PMID: 3304391 DOI: 10.1111/j.1365-2141.1987.tb06913.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bone marrow aspirates from patients with cerebral malaria were studied with the light and electron microscopes. Various abnormalities were found including: (1) an increase in plasma cells and macrophages, sometimes to a marked degree; (2) phagocytosis of parasitized red cells by macrophages and of merozoites by neutrophil metamyelocytes, neutrophil granulocytes and macrophages; (3) an increase in the proportion of eosinophil granulocytes and their precursors; (4) the presence of giant metamyelocytes; and (5) morphological abnormalities of erythroblasts, particularly irregularly-shaped nuclei and karyorrhexis. A high percentage of the red cells within marrow sinusoids were parasitized and the parasitized cells were attached to the endothelium. Some marrow sinusoids were packed with and completely obstructed by parasitized cells. Strands of electron-dense material were sometimes found connecting the knobs of parasitized red cells to endothelial cells or to the knobs of adjacent parasitized red cells. A striking finding was a complex interdigitation between cytoplasmic processes developed by some of the parasitized red cells and those developed by the endothelial cells to which they were attached. Occasionally, cytoplasmic processes arising from marginated parasitized red cells completely penetrated the endothelial cell and emerged extravascularly. Several parasitized red cells were also found extravascularly between haemopoietic cells. Sequestration of parasitized red cells within small blood vessels may play a part in the pathogenesis not only of the encephalopathy of cerebral malaria but also of the bone marrow dysfunction in severe malaria.
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Looareesuwan S, White NJ, Warrell DA, Forgo I, Dubach UG, Ranalder UB, Schwartz DE. Studies of mefloquine bioavailability and kinetics using a stable isotope technique: a comparison of Thai patients with falciparum malaria and healthy Caucasian volunteers. Br J Clin Pharmacol 1987; 24:37-42. [PMID: 3304385 PMCID: PMC1386277 DOI: 10.1111/j.1365-2125.1987.tb03133.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
1 A mefloquine hydrochloride tablet (250 mg base equivalent to 4.8 +/- 0.6 mg kg-1; mean +/- s.d.) and deuterium labelled mefloquine hydrochloride solution (250 mg base) were given to six adult male Thai patients with acute falciparum malaria and six healthy Swiss adult male volunteers (equivalent to 3.5 +/- 0.1 mg kg-1). 2 The relative bioavailability of the tablet formulation derived from comparison of the areas under the plasma concentration-time curves was similar in both groups; 87 +/- 11% and 89 +/- 10% (mean +/- s.d.). 3 The rate of drug absorption appeared to be similar in the two groups but peak plasma mefloquine concentrations were approximately three times higher in the Thai patients (1004 +/- 276 ng ml-1 for the tablet and 1085 +/- 280 ng ml-1 for the suspension) compared with the Swiss volunteers (319 +/- 73 ng ml-1 for the tablet, and 369 +/- 121 ng ml-1 for the suspension). 4 Estimates of the oral clearance CLpo of unlabelled mefloquine were significantly lower (17.5 +/- 4.4 ml h-1 kg-1) in the Thai patients compared with 28.8 +/- 3.5 ml h-1 kg-1 in the Swiss volunteers; P less than 0.05). Terminal elimination half-lives were significantly shorter in the patients (10.3 +/- 2.5 days) than in the volunteers (16.7 +/- 1.9 days; P less than 0.005). Differences of a similar magnitude were observed when comparing the pharmacokinetic parameters derived from the deuteromefloquine plasma concentrations. 5 Both genetic and disease related factors are likely to account for the large pharmacokinetic differences between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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Karbwang J, Looareesuwan S, Phillips RE, Wattanagoon Y, Molyneux ME, Nagachinta B, Back DJ, Warrell DA. Plasma and whole blood mefloquine concentrations during treatment of chloroquine-resistant falciparum malaria with the combination mefloquine-sulphadoxine-pyrimethamine. Br J Clin Pharmacol 1987; 23:477-81. [PMID: 3555581 PMCID: PMC1386099 DOI: 10.1111/j.1365-2125.1987.tb03079.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Mefloquine-sulphadoxine-pyrimethamine (MSP) in combination has proved effective against multiple-drug-resistant falciparum malaria, but nothing is known about mefloquine absorption when it is given in this formulation. Nine Thai patients, aged 15-51 years with uncomplicated chloroquine-resistant falciparum malaria, took 11.2-16.7 mg of mefloquine base per kilogram bodyweight as MSP tablets. All patients responded to treatment with fever and parasite clearance times of 61 +/- 29 h (mean +/- s.d.) and 52 +/- 24 h, respectively. The mean apparent absorption half-time (t1/2abs) of mefloquine was 4.89 h (range 2.25-9.72) and mean peak plasma concentration was 1815 ng ml-1 (range 725-3368). Peak plasma mefloquine concentrations in three patients who vomited within 2 h of treatment were 725, 956 and 1972 ng ml-1. There was no significant difference between plasma and whole blood mefloquine concentrations during the first 48 h of treatment. Based on the elimination of parasitaemia, the plasma mefloquine concentrations are adequate for therapy of uncomplicated falciparum malaria although the relationship between plasma concentrations and therapeutic efficacy of mefloquine requires further study.
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Edwards G, Davies AJ, Phillips RE, Looareesuwan S, Karbwang J, White NJ, Warrell DA. Plasma concentrations and toxicity of chloroquine after slow intravenous infusion in patients with falciparum malaria. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1987; 81:79-84. [PMID: 3318731 DOI: 10.1080/00034983.1987.11812098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Five male patients with acute Plasmodium falciparum or Plasmodium vivax infections were infused with chloroquine diphosphate (15 mg kg-1) over four hours. Further does of chloroquine diphosphate (5 mg kg-1) were given at 12, 24, 36 and 60 hours. Plasma chloroquine concentrations were determined before and four hours after each dose and then daily until discharge. No serious cardiovascular toxicity was observed, and plasma chloroquine concentrations exceeding the putative minimum inhibitory concentration (MIC) of sensitive P. falciparum strains were reached within four hours of starting treatment. Further doses produced plasma concentrations which were sustained above the putative MIC, but showed no rapid increase into the range associated with toxicity.
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184
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Chapel HM, Warrell DA, Looareesuwan S, White NJ, Phillips RE, Warrell MJ, Supawanta V, Tharavanij S. Intrathecal immunoglobulin synthesis in cerebral malaria. Clin Exp Immunol 1987; 67:524-30. [PMID: 3301098 PMCID: PMC1542621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Local synthesis of immunoglobulin within the central nervous system has been evaluated in 37 patients with acute cerebral malaria; seven patients were also studied in the convalescent phase. There was evidence in the cerebrospinal fluid (CSF) of 21 patients that intrathecal IgG synthesis occurs in the acute phase. There were raised IgG: albumin ratios in 43% of acute patients. Oligoclonal IgG bands or cathodal IgG was seen in the CSF of 43% of patients tested by polyacrylamide electrophoresis. Only eight out of 37 acute patients (22%) had no evidence of intrathecal IgG synthesis by either method. The serial studies showed that most patients had IgG-CSF abnormalities when tested in convalescence. These studies suggest that an immune stimulus (perhaps malarial antigens or mitogens) may be present in the brain in acute cerebral malaria.
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185
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Silamut K, Ho M, Looareesuwan S, Viravan C, Wuthiekanun V, Warrell DA. Detection of venom by enzyme linked immunosorbent assay (ELISA) in patients bitten by snakes in Thailand. BRITISH MEDICAL JOURNAL 1987; 294:402-4. [PMID: 3101897 PMCID: PMC1245411 DOI: 10.1136/bmj.294.6569.402] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The ability of an enzyme linked immunosorbent assay (ELISA) to detect venom was evaluated in 251 patients bitten by four of the commonest poisonous snakes in Thailand. Serum was tested only from patients who brought the snakes that had bitten them. About one third of all bitten patients had detectable venom antigenaemia, though a smaller proportion were symptomatic. Serum venom concentrations on admission correlated with the severity of clinical manifestations. The test was sensitive and specific even for specimens that had been collected and stored under suboptimal conditions. The technique is suitable for forensic use in cases of suspected snakebite. The combination of snake identification and venom antigen detection should be a more reliable means of studying the epidemiology of snakebite than the measurement of venom antibodies in a population.
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186
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Hutton RA, Phillips RE, Warrell DA. Evolution of coagulation abnormalities following Russell's viper bite in Burma. Br J Haematol 1987; 65:193-8. [PMID: 3828227 DOI: 10.1111/j.1365-2141.1987.tb02264.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The evolution of coagulation abnormalities was studied in Russell's viper bite victims who, on admission to hospital, showed no clinical signs of systemic envenoming. Based on the laboratory results and subsequent clinical course, three groups were distinguished. The first group, consisting of five cases, showed no activation of coagulation at any stage. The second group, consisting of six cases, developed mild to moderate abnormalities in some tests, particularly in the aPTT and factor V assay, which corrected to normal without treatment. The third group, consisting of nine patients, developed haemostatic abnormalities as early as 1-2 h after the bite, which progressed to severe defibrination 4-8 h later at which time antivenom was given. Comparison of the haemostatic abnormalities in the three groups suggested that serial monitoring of the serum FDP concentration may be of value in predicting the likelihood of systemic envenoming and progression to complete defibrination.
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187
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White NJ, Looareesuwan S, Edwards G, Phillips RE, Karbwang J, Nicholl DD, Bunch C, Warrell DA. Pharmacokinetics of intravenous amodiaquine. Br J Clin Pharmacol 1987; 23:127-35. [PMID: 3828191 PMCID: PMC1386059 DOI: 10.1111/j.1365-2125.1987.tb03020.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Amodiaquine hydrochloride (3 mg base kg-1) was given by constant rate intravenous injection over 10 min to seven healthy adult male volunteers, and by constant rate infusion (10 mg base kg-1) over 4 h to 10 adult patients admitted to hospital with falciparum malaria. After intravenous injection in volunteers there was considerable variation in plasma concentration profiles between subjects; peak plasma concentrations ranged between 65 and 1921 ng ml-1. A biexponential equation was fitted to the plasma concentration time data and the following estimated pharmacokinetic parameters (geometric mean; range) were derived; lambda 1 = 24.4 (7.6-95.0) h-1, lambda 2 = 0.33 (0.12-0.79) h-1, V1:1.1 (0.3-3.6) 1 kg-1, Vss: 17.4 (2.3-95.9) 1 kg-1 and systemic clearance 13.0 (4.7-56.6) 1 kg-1 h-1. After intravenous infusion there was also considerable variability between patients with post-infusion plasma concentrations ranging between 82 and 836 ng ml-1. The plasma concentration-time profiles were biphasic with the following estimated pharmacokinetic parameters (geometric mean; range) alpha = 1.87 (0.60-8.52) h-1, beta = 0.069 (0.021-0.265) h-1, V1: 4.6 (0.5-29.3) 1 kg-1, Vss: 38.3 (3.7-127.9) 1 kg-1 and systemic clearance CL (1.6-17.3) 1 kg-1 h-1. There was no measurable long terminal elimination phase, and the principal metabolite desethyl amodiaquine was not detected in the plasma samples. There was no serious toxicity in either group. During intravenous injection there was a significant fall in systolic blood pressure in four subjects (mean fall 16 mm Hg) but there was no significant change in heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)
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188
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Chanthavanich P, Suntharasamai P, Warrell MJ, Viravan C, Looareesuwan S, Supanaranond W, Karbwang J, Warrell DA, Phillips RE, Sinhaseni A. Antibody response to suckling mouse brain rabies vaccines for post exposure treatment. Trans R Soc Trop Med Hyg 1987; 81:260-3. [PMID: 3617187 DOI: 10.1016/0035-9203(87)90234-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A new suckling mouse brain vaccine (SMBV) against rabies, produced by the Thai Red Cross Society, was compared with the well established Institut Pasteur SMBV in patients with very low risk rabies contact. The 4 regimens used were the standard daily injections with booster doses of Thai Red Cross vaccine (TRCV) and Institut Pasteur Vaccine (IPV), and a reduced dose scheme of 6 injections as used for tissue culture vaccines. The effect of 20 IU/kg of human rabies immune globulin (HRIG) was tested on each regimen, making 8 groups, a total of 122 patients. Blood samples taken on days 0, 7, 14, 28 and 91 were tested for neutralizing antibody. Only the standard IPV regimen produced antibody in every patient; all had levels greater than 0.5 IU at some stage. Two people (13%) given the standard TRCV produced no detectable antibody (less than or equal to 0.1 IU) throughout the study. The reduced dose regimens gave very low antibody levels. 7% of the IPV and 76% of the TRCV groups failed to produce antibody on any occasion. The antibody response was significantly suppressed by the administration of HRIG. Compared to the original South American SMBV, the vaccines tested induced low levels of short lived antibody. No reduction in the dosage of SMBV should be considered unless the potency of the product is adequate.
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189
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Pukrittayakamee S, Ratcliffe PJ, McMichael AJ, Warrell DA, Bunnag D. A competitive radioimmunoassay using a monoclonal antibody to detect the factor X activator of Russell's viper venom. Toxicon 1987; 25:721-9. [PMID: 3313812 DOI: 10.1016/0041-0101(87)90122-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A radioimmunoassay (RIA) has been developed for the detection of Russell's viper venom in body fluids. This is a competitive binding technique using a monoclonal antibody directed against the factor X activator of Russell's viper venom. The sensitivity of the test in urine was 4 ng/ml, in 0.1% bovine serum albumin-phosphate buffered saline it was 20 ng/ml and in serum it was 5 micrograms/ml. This was adequate to detect venom in the serum of four patients bitten by Russell's viper. Urine from an isolated kidney preparation perfused with Russell's viper venom contained coagulant activity and was positive using the competitive RIA. Testing of sera from other envenomated patients and pure venom from seven other species of snake indigenous to Thailand revealed RIA cross reactivity between cobra venom and Russell's viper venom. In practice, the absence of coagulant activity in cobra venom clearly distinguishes between the two. Although further development is required to elucidate the serum factors interfering with this assay, this is a promising technique, which is of potential value in the diagnosis and investigation of the pathophysiology of Russell's viper envenomation.
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Tun-Pe, Tin-Nu-Swe, Myint-Lwin, Warrell DA, Than-Win. The efficacy of tourniquets as a first-aid measure for Russell's viper bites in Burma. Trans R Soc Trop Med Hyg 1987; 81:403-5. [PMID: 2961108 DOI: 10.1016/0035-9203(87)90150-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The efficacy of the tourniquets commonly used by Russell's viper bite victims in retarding venom movement from the bite was studied in 37 cases by measuring venom antigen levels by enzyme-linked immunosorbent assay in venous samples taken proximal and distal to the tourniquets and also before and after release of tourniquets. In most cases, the tourniquet did not prevent proximal spread of venom. In 8/37 cases, however, venom antigen assays suggested but did not prove that venom absorption was being delayed by the tourniquet.
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191
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Abstract
The term severe falciparum malaria implies an infection with manifestations and complications which are potentially fatal in man, the natural host for this parasite. Much that has been written on the pathophysiology of animal malarias is of doubtful relevance to the understanding of the mechanism ofPlasmodium falciparuminfection in man. The clinical picture of severeP. falciparuminfection differs in several respects from severe animal malarias, even those of non-human primates. Cerebral dysfunction is the most common severe manifestation of falciparum malaria in man. Coma develops suddenly after a generalized convulsion or gradually towards the end of the first week of illness. There are signs of a symmetrical upper motor neurone lesion and brain-stem dysfunction, but only about 5% of survivors show persisting neurological deficit after 2 or 3 days of unconsciousness. The mortality of cerebral malaria depends on how it is defined and on the predominant age group and other factors. In patients with proved acuteP. falciparuminfection with unrousable coma, in whom other causes of encephalopathy have been excluded, the mortality is between 15 and 50% despite treatment with antimalarial drugs (Warrell, Looareesuwan, Warrell, Kasemsarn, Intaraprasert, Bunnag & Harinasuta, 1982).
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192
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Suntharasamai P, Warrell MJ, Warrell DA, Chanthavanich P, Looareesuwan S, Supapochana A, Phanuphak P, Jittapalapongsa S, Yager PA, Baer GM. Early antibody responses to rabies post-exposure vaccine regimens. Am J Trop Med Hyg 1987; 36:160-5. [PMID: 3812881 DOI: 10.4269/ajtmh.1987.36.160] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The aim of post-exposure rabies vaccine treatment is to induce immunity, measured as neutralizing antibody, as fast as possible. This is especially important in the tropical rabies-endemic areas where simultaneous passive prophylaxis with hyperimmune serum is not practicable in the majority of cases. We compared the rate of production of antibody during the first two weeks, by six vaccine regimens in 118 subjects using two tissue culture vaccines, human diploid cell strain vaccine (HDCSV) and purified Vero cell rabies vaccine (PVRV). No antibody was detected on day 5. On day 7, the highest seroconversion rate was seen in subjects given HDCSV intramuscularly at two sites on days 0 and 3 (7 of 15), but this was not significantly different from the group with the lowest rate: the conventional single-site intramuscular regimen. All subjects had antibody by day 14, at which time the highest geometric mean titer was in the group vaccinated with 0.25 ml doses of diploid cell vaccine given subcutaneously at eight sites. This regimen, together with the standard single-site diploid cell vaccine and an eight-site intradermal regimen of the same product gave significantly higher titers than the two-site intramuscular regimens of either product. No single immunization schedule emerges as best, so the speed of antibody response, economy, and the skill needed for intradermal injection should be considered when deciding on the optimum regimen for use in a particular geographic area.
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193
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Watt G, Theakston RD, Hayes CG, Yambao ML, Sangalang R, Ranoa CP, Alquizalas E, Warrell DA. Positive response to edrophonium in patients with neurotoxic envenoming by cobras (Naja naja philippinensis). A placebo-controlled study. N Engl J Med 1986; 315:1444-8. [PMID: 3537783 DOI: 10.1056/nejm198612043152303] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
To study the ability of anticholinesterase drugs to reverse the potentially fatal paralytic effects of cobra venom, we conducted a placebo-controlled, double-blind crossover trial of intravenous edrophonium (Tensilon) in 10 adults with neurotoxic envenoming caused by bites of the Philippine cobra (Naja naja philippinensis). There was significantly more improvement in ptosis and endurance of upward gaze after edrophonium than after placebo. Five minutes after injection, the mean difference (+/- SD) in the percentage of the iris that was uncovered was 39 +/- 5.47 (70 vs. 31 percent; P less than 0.01), and the mean difference in the number of seconds of upward gaze was 33.1 +/- 9.29 (39.7 vs. 6.6 seconds; P less than 0.01). The expiratory and inspiratory pressures, forced vital capacity, and ability to cough, speak, and swallow also improved after edrophonium. In both the patients who were studied electromyographically, pretreatment and postplacebo responses were typical of myasthenia gravis and became normal after edrophonium. We conclude that anticholinesterases are beneficial in the management of neurotoxic envenoming by Asian cobras (Naja naja), and we recommended a test of edrophonium in any patient with signs of neurotoxic envenoming after snakebite.
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194
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Sriwanthana B, Phanuphak P, Thaweepathomwat M, Warrell MJ, Warrell DA, Suntharasamai P, Baer GM. Effect of inosiplex on the humoral and cell-mediated immune responses to intradermal human diploid cell rabies vaccine. THE SOUTHEAST ASIAN JOURNAL OF TROPICAL MEDICINE AND PUBLIC HEALTH 1986; 17:543-9. [PMID: 2437660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Antigen-stimulated lymphocyte transformation was studied in recipients of intradermal human diploid cell rabies vaccine (HDCV). HDCV was administered intradermally at 8 different anatomical sites, 0.1 ml each, on day 0; followed by another 4-site injection on day 7. Rabies antigen-stimulated in vitro proliferative response was evident as early as 7 days after starting immunization. It reached a peak on day 14 and had declined by day 28. The cellular proliferative response preceded and roughly correlated with the antirabies antibody response. Simultaneous administration of inosiplex, an antiviral and immunopotentiating drug, during the first 10 days of intradermal HDCV immunization did not result in heightened antibody titres or cell-mediated immune response to the vaccine. The number of T cells and the lymphocyte proliferative response to phytohaemagglutinin in inosiplex-treated vaccinees were similarly not significantly different from untreated controls. Our results confirm other previous findings that a specific cell-mediated immune response can be consistently and rapidly induced by an intradermal regimen of HDCV immunization. The addition of inosiplex to this regimen did not enhance the humoral or cell-mediated immune responses to the vaccine. The apparent lack of immunostimulating effect of inosiplex in this setting may be the result of several factors such as the immunization schedule and the immunologic parameters examined.
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195
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Warrell DA, Looareesuwan S, Theakston RD, Phillips RE, Chanthavanich P, Viravan C, Supanaranond W, Karbwang J, Ho M, Hutton RA. Randomized comparative trial of three monospecific antivenoms for bites by the Malayan pit viper (Calloselasma rhodostoma) in southern Thailand: clinical and laboratory correlations. Am J Trop Med Hyg 1986; 35:1235-47. [PMID: 3538922 DOI: 10.4269/ajtmh.1986.35.1235] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Three monospecific antivenoms for Malayan pit viper (MPV) (Calloselasma rhodostoma) were compared in Southern Thailand, where this species is the most common cause of snake bite morbidity. Forty-six patients with proved MPV bites and incoagulable blood, indicating systemic envenoming, were randomly allocated for treatment with Thai Red Cross (TRC), Thai Government Pharmaceutical Organization (GPO), or Twyford Pharmaceutical monospecific antivenoms. Both GPO and Twyford antivenoms produced rapid and permanent restoration of blood coagulability, but TRC antivenom failed in 2/15 cases. Patients in the GPO group showed the greatest increase in plasma fibrinogen concentration during the first 24 hr and had fewer early anaphylactic reactions (6/15) compared with Twyford 8/16 and with TRC 13/15. Pyrogenic reactions occurred more frequently after TRC antivenom (8/15) than GPO (1/15) or Twyford (0/16). Patients requiring more than one dose of antivenom were identifiably more severely envenomed on admission. In an accompanying laboratory study the antivenoms were assessed in rodents using five WHO standard tests of neutralizing activity. Compared with the other two antivenoms TRC was significantly inferior in anti-lethal potency, GPO was superior in anti-hemorrhagic and anti-necrotic potency and Twyford was superior in anti-procoagulant and anti-defibrinogenating potency. The clinical efficacy of these antivenoms against local necrosis remains equivocal. GPO and Twyford antivenoms are recommended for the treatment of systemic envenoming by MPV in an initial dose of 5 ampoules.
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Abstract
By the end of the 1940s, the clinical and pathological features of severe falciparum malaria had been well described by military physicians and pathologists working in theatres of war where the disease was endemic. From that time serious efforts were made to discover the pathophysiology of the severe manifestations of malaria because an understanding of these mechanisms forms an important basis for the clinical management of affected patients. Recently, after a period of neglect, there has been a revival of interest in malaria as a subject for clinical and laboratory research. In this article, Rodney Phillips and David Warrell review aspects of that work and attempt to unravel the mysteries of the pathophysiology of severe malaria in man.
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197
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Merry AH, Looareesuwan S, Phillips RE, Chanthavanich P, Supanaranond W, Warrell DA, Weatherall DJ. Evidence against immune haemolysis in falciparum malaria in Thailand. Br J Haematol 1986; 64:187-94. [PMID: 3530315 DOI: 10.1111/j.1365-2141.1986.tb07586.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Evidence of immune mediated haemolysis was sought in 83 patients with P. falciparum malaria in eastern Thailand. Amongst 73 patients with uncomplicated infection 12 (16.4%) had a weakly positive direct antiglobulin test (DAT). The incidence in 32 children aged 8-16 years was similar to that in adults. Of 10 patients with cerebral malaria, six adults, all of whom were in unrousable coma, had a positive DAT. Erythrocyte-bound IgG1 accounted for the positive DAT in all cases; sensitization with complement or other IgG subclasses was not found. Patients with uncomplicated malaria had a median value of 70 IgG molecules per erythrocyte compared with 65 molecules per cell in 67 healthy controls. This difference was not statistically significant but could account for the lower incidence of a positive DAT in control subjects (4.5%). There was no correlation between the number of IgG molecules per cell and the degree of anaemia during the acute or convalescent phases of the infection. There is no evidence from this study that an immunohaemolytic process contributes to the anaemia of falciparum malaria in eastern Thailand.
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198
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Warrell DA, Looareesuwan S, Phillips RE, White NJ, Warrell MJ, Chapel HM, Areekul S, Tharavanij S. Function of the blood-cerebrospinal fluid barrier in human cerebral malaria: rejection of the permeability hypothesis. Am J Trop Med Hyg 1986; 35:882-9. [PMID: 2429567 DOI: 10.4269/ajtmh.1986.35.882] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We tested the hypothesis that cerebral malaria is caused by blood-brain barrier inflammation and cerebral edema. In a group of 157 Thai patients with strictly defined cerebral malaria, cerebrospinal fluid (CSF) opening pressures were normal in 79% and were lower in fatal cases than in survivors (means +/- 1 SD, 144 +/- 58 and 167 +/- 51 mm CSF, respectively, P = 0.051). CSF: serum albumin ratios (X 10(3)) in 39 of them were significantly higher than in 61 British controls (medians 8.5 and 5.5, respectively, P = 0.04), but were no higher in 7 fatal cases. In a group of 12 patients this ratio was not significantly higher during coma than after full recovery (means +/- 1 SD, 9.0 +/- 6.2 and 6.7 +/- 4.2, respectively, P greater than 0.1). CSF alpha 2-macroglobulin concentrations were always normal. CSF : serum 77Br- ratios were elevated in 11/19 comatose cases but fell to normal 4 to 9 days later in 11/11 cases. Dexamethasone treatment had no significant effect on bromide partition. The percentage of an intravenously administered dose of 125I-human serum albumin detectable per ml of CSF 6 hr after intravenous injection was 2.4 +/- 1.3 X 10(-5) in 14 comatose patients and 4.4 +/- 4.0 X 10(-5) in 9 of them during convalescence (P greater than 0.1). These results demonstrate that the blood-CSF barrier is essentially intact in patients with cerebral malaria and give no support to the idea that cerebral edema is the cause of coma.
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199
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Suntharasamai P, Warrell MJ, Warrell DA, Viravan C, Looareesuwan S, Supanaranond W, Chanthavanich P, Supapochana A, Tepsumethanon W, Pouradier-Duteil X. New purified Vero-cell vaccine prevents rabies in patients bitten by rabid animals. Lancet 1986; 2:129-31. [PMID: 2873399 DOI: 10.1016/s0140-6736(86)91946-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The protective effect of a new, potentially economical tissue-culture rabies vaccine, purified vero-cell rabies vaccine (PVRV), was tested in 106 patients bitten by animals with proven rabies. 0.5 ml PVRV was given intramuscularly on days 0, 3, 7, 14, 28, and 91; 47 patients with severe exposure were also given 20 IU/kg human rabies immune globulin (HRIG). All patients are alive and well after 1 year. Side-effects of treatment were negligible. Rabies neutralising antibody (greater than or equal to 1.6 IU) was demonstrated on day 14 and persisted for 1 year in every case. There was no significant suppression of the antibody response by HRIG. If the untreated mortality is 15%, PVRV is 81% efficient in protecting patients against rabies encephalitis (95% confidence limit). PVRV is likely to replace human diploid-cell strain vaccine as the most widely used tissue-culture rabies vaccine.
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Wattanagoon Y, Phillips RE, Warrell DA, Silamut K, Looareesuwan S, Nagachinta B, Back DJ. Intramuscular loading dose of quinine for falciparum malaria: pharmacokinetics and toxicity. BRITISH MEDICAL JOURNAL 1986; 293:11-3. [PMID: 3524743 PMCID: PMC1340765 DOI: 10.1136/bmj.293.6538.11] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In a study of intramuscular injection of quinine eight adults with moderately severe falciparum malaria resistant to chloroquine were treated with quinine dihydrochloride, being given a loading dose of 20 mg salt (16.7 mg base)/kg followed by three or four eight hourly maintenance doses of 10 mg salt (8.3 mg base)/kg injected into the anterior thigh. All patients responded to treatment. Fever and parasite clearance times (mean (SD) 60 (23) h and 53 (22) h respectively) were comparable with those obtained with intravenous quinine. The mean peak plasma quinine concentration of 11.0 mg/l (34.4 mu mol/l) [corrected] was reached a median of five hours after administration of the loading dose. In all patients plasma quinine concentrations exceeded the high minimum inhibitory concentration for Plasmodium falciparum malaria prevalent in Thailand within four hours of the start of treatment but did not cause toxicity other than mild cinchonism. When intravenous infusion is not possible an intramuscular quinine loading dose is an effective means of starting treatment in patients with moderately severe falciparum malaria who cannot swallow tablets.
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