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Biomedical subjects

V Sitprija

Publications and source records attributed to V Sitprija.

At least 37 records · Page 2Linked to original sources
PubMed2000

Detection of rabies virus antigen in dog saliva using a latex agglutination test.

Dog bites are responsible for more than 90% of human rabies deaths in Asia. We developed a simple and inexpensive test based on latex agglutination (LA) for rabies virus antigen detection in dog saliva. Rabies virus antigen could be detected by agglutination on a glass slide using latex particles coated with gamma globulin. By evaluation of paired saliva-brain specimens from 238 dogs, the LA test using saliva was 99% specific and 95% sensitive compared to the fluorescent antibody test (FAT) on brain smears. The advantages of the LA test over the standard FAT are that it is comparatively simple and there is no need to kill the animal before examination.

Animals↗
PubMed2000

Mediators and renal hemodynamics in Russell's viper envenomation.

The effects of Russell's viper venom on vasoactive mediators and renal hemodynamics were studied in five mongrel dogs. Intravenous administration of Russell's viper venom to the dogs caused a reduction of mean arterial pressure, renal blood flow, and glomerular filtration rate. The filtration fraction was decreased. This was accompanied by a rise in plasma norepinephrine, endothelin, 6-keto-PGF1 alpha, a stable metabolite of PGI2, and TXB2, a metabolite of TXA2. Plasma levels of epinephrine and dopamine showed no significant changes. The increase of plasma levels of both vasodilatator and vasoconstrictor were critical to systemic and renal hemodynamics. While vasodilatation predominated in the systemic circulation and resulted in hypotension, vasoconstriction played a major role in decreasing renal hemodynamics. Decreased renal blood flow and decreased glomerular filtration rate were the result of renal vasoconstriction and hypotension.

Animals↗
PubMed1999

Environmental distal renal tubular acidosis in Thailand: an enigma.

Distal renal tubular acidosis is a common health problem in northeastern Thailand, with the population background of the low potassium intake, low urine citrate, and decreased red blood cell Na-K adenosine triphosphatase (ATPase) activity and the environment of the high soil vanadium. The disease is usually seen in the people with low socioeconomic status in summer. The patients have decreased gastric acidity and low urine potassium. There are varying degrees of renal function from normal to impairment. Gastric hypoacidity is an important clue. Defects in H-K ATPase and anion exchange (AE2) mechanism are considered. The urine vanadium is higher in the patients than that of normal rural northeastern villagers. Inhibition of H-K ATPase by vanadium seems possible and requires more supporting evidence. AE1 gene mutation is noted in few patients. The cause of dRTA is not apparent. The AE2 gene and H-K ATPase gene remain to be studied. Both environmental and genetic factors could contribute to the pathogenesis of the disease.

Acidosis, Renal Tubular↗
PubMed1999

Renal pathology and HIV infection in Thailand.

The existence of a human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) as a distinct disease entity characterized by glomerulosclerosis is well established in North America and Western Europe. Although the large number of HIV-infected cases overwhelm the Asian countries, no cases of HIVAN are documented in the literature. We studied 26 cases of HIV-infected Thai patients with proteinuria greater than 1.5 g/d of protein during 1995 and 1996. None of the patients were treated with antiretroviral drugs at the time of renal biopsy. Intravenous drug addiction and sexual transmission were risk factors in 11 and 15 patients, respectively. Pathological examinations were performed by light microscopic and immunoperoxidase study. Mesangial proliferative glomerulonephritis was found in 17 cases, immunoglobulin A (IgA) nephropathy in 2 cases, and diffuse proliferative glomerulonephritis and interstitial nephritis secondary to cryptococcal infection in 2 cases each. One case each had membranous glomerulopathy, membranoproliferative glomerulonephritis, and granulomatous interstitial nephritis secondary to tuberculosis. The renal pathological findings of HIVAN with the unique features described in previous literature were not evident in these patients. Although the data in this study are limited to 26 HIV-infected Thai patients, we believe that HIVAN is uncommon in the Asian HIV-infected population.

Adolescent↗
PubMed1999

Antibody response after a four-site intradermal booster vaccination with cell-culture rabies vaccine.

The current World Health Organization recommendation for booster vaccination of previously immunized individuals with potential exposure to rabies is two doses of vaccine intramuscularly or intradermally on days 0 and 3. We report responses to two types of postexposure treatment of healthy individuals who had received preexposure rabies vaccination 1 year previously. Group A individuals received four intradermal doses (one-fifth of the diluent volume of vaccine per dose) on day 0, and group B individuals received two intramuscular doses on days 0 and 3. Immunogenicity of the two booster regimens was assessed by titrating the amount of neutralizing antibody (Nab). We found that the booster doses of vaccine produced remarkable responses in all subjects. Nab titers of > or = 0.5 IU/mL (acceptable antibody level for protection against rabies) were detected in all subjects on day 14, and they were shown to be consistently high 1 year after the booster vaccination. We also found that the Nab titers for group A were significantly higher (two- to eightfold) than those for group B on days 5, 14, 150, and 360 after the initial booster vaccination (P < .05). Our study shows that the four-site intradermal booster regimen with use of one-fifth of the diluent volume of cell-culture rabies vaccine on day 0 is associated with a significantly higher antibody response than is the conventional booster regimen for subsequent postexposure rabies treatment of individuals who have received preexposure rabies vaccination with cell-culture rabies vaccine 1 year previously.

Antibodies, Viral↗
PubMed1999

Genus specific neutralization of Bungarus snake venoms by Thai Red Cross banded krait antivenom.

Thai commercial antivenom raised to Bungarus fasciatus venom neutralized the lethal activity of all Thai Bungarus venoms tested in in vitro neutralization experiments. The neutralizing capacities against B. fasciatus and B. candidus venoms were almost the same, but that against B. flaviceps venom was significantly greater. The efficacy of the antivenom was confirmed in in vivo neutralization experiments also. Results of immunochemical analyses supported results of the animal experiments suggesting the presence of genus specific neutralization.

Animals↗
PubMed1999

Development of reversed passive latex agglutination for detection of Thai cobra (Naja kaouthia) venom.

A simple, rapid, and sensitive diagnostic kit for detecting Thai cobra (Naja kaouthia) venom was developed using latex particles sensitized with venom specific immunoglobulin. The kit is capable of detecting 25-50 ng/ml of Thai cobra venom. The capability was not affected by human plasma. Specificity of the kit was proven using snake venoms from Vipera russelli, Calloselasma rhodostoma, Trimeresurus albolabris, Naja siamensis, Ophiophagus hannah, and Bungarus fasciatus. The diagnostic kit does not lose its capability under refrigeration for two months and by lyophilization.

Chromatography, Affinity↗
PubMed1999

Nephrotoxicity in snake envenomation.

There is a broad spectrum of renal involvement following snake envenomation. At the clinical level the renal manifestation may be absent or minimal. Mild proteinuria with abnormal urinary sediment may be observed. Significant proteinuria is uncommon. Hematuria and hemoglobinuria are seen in envenomation by vipers or crotalids, while myoglobinuria follows envenomation of sea snakes or elapids. Acute renal failure can occur in these snake bites. All renal structures can be involved. Mesangial proliferative glomerulonephritis is common. Tubular necrosis is the important pathological counterpart of acute renal failure. Three mechanisms including hemodynamic alterations, immunologic reactions, and direct nephrotoxicity are incriminated in the pathogenesis of renal lesions.

Acute Kidney Injury↗
PubMed1999

Pathophysiological effects of Russell's viper venom on renal function.

Pathophysiological effects of Russell's viper venom (RVV) on renal function are reviewed. The evidence in experimental animals on the mechanisms of venom action in relation to changes in either extrarenal or intrarenal factors is considered. The cardiovascular system and renal hemodynamics are affected by the venom. Mean arterial blood pressure, heart rate, cardiac output, and renal hemodynamics decrease, while total peripheral vascular resistance and renal vascular resistance increase in the initial post-injection period of envenoming. After the transitory decrease, all parameters for general circulation gradually increase, returning to near normal level within 30 min, while an increase in renal vascular resistance and decreases in renal blood flow and glomerular filtration rate are still apparent 48 h after envenomation. The effects of venom on renal vasoconstriction are discussed. Possible factors, especially humoral factors, inducing these changes are considered. Russell's viper venom is also able to affect renal tubular cells directly. This can be explained based on available data from in vitro studies. Different studies have been performed to investigate venom action in the isolated perfused kidney, changes in the characteristic polarization of the cell membrane, changes in mitochondria activity and changes in Na, K-ATPase activity of the tissue of both the renal cortex and medulla during envenomation.

Animals↗
PubMed1998

Envenomation of mice by Thai cobra (Naja kaouthia) venom: tolerable venom concentration and exposure time.

Naja kaouthia venom appeared in circulation rapidly after intramuscular injection into mice. The venom concentration attained a maximum level with all doses examined after 20 min. The half value of the maximum level was obtained 1 min after injection when a dose of 4LD50 was used. A critical venom concentration endangering mice was assessed from venom concentration in the sera of mice envenomed with sublethal dose (LD50). A fatal condition was produced within 30 min at a venom concentration of 200-300 ng/ml or within 50 min at a venom concentration of 100-150 ng/ml.

Animals↗
PubMed1998

Safety and efficacy of purified Vero cell rabies vaccine given intramuscularly and intradermally. (Results of a prospective randomized trial).

OBJECTIVES: To determine adverse reactions as a result of pre- and post-exposure rabies vaccination, using the conventional intramuscular, and reduced dose intradermal regimens and purified Vero cell rabies vaccine. DESIGN: A prospective and randomized study of patients exposed to rabies and of subjects in need of pre-exposure rabies vaccination. SETTING: A metropolitan rabies control center in a canine rabies endemic country. PATIENTS: 1198 subjects were recruited between May, 1994 and March, 1996. They were divided into four groups. Patients with suspected or proven rabies exposures were given the vaccine intramuscularly using the conventional regimen, or intradermally using the World Health Organization approved Thai Red Cross schedule. Human or equine rabies immune globulin was administered where indicated. Pre-exposure and post-exposure vaccine recipients were divided randomly into two groups each and given the vaccine either by the intramuscular or intradermal schedules. MEASUREMENTS: All local and systemic adverse reactions were recorded and statistically analyzed. RESULTS: Pruritus at injection sites was the only significant local reaction. It was more common in the intradermal groups. Low-grade fever, the only significant adverse systemic event, was more common in the intramuscular groups and was noted in 8% of all subjects. Eighty-four patients bitten by proven rabid animals were found to be alive and well 3 years later. Forty-four of these had received the intramuscular and 40 the intradermal postexposure regimens with human or equine immune globulin injected into wounds on the first day of treatment. CONCLUSIONS: Purified Vero cell rabies vaccine is safe, carries a very low adverse reaction rate and is effective in preventing rabies in severely exposed subjects when used with human or equine rabies immune globulin.

Adult↗
PubMed1998

Falciparum malaria and the kidney: a model of inflammation.

Renal and renal-related disorders commonly occur in infection with Plasmodium falciparum, which can cause fluid and electrolyte disorders, glomerulonephritis, and acute renal failure (ARF). It appears that ARF and other life-threatening complications in falciparum malaria are not directly caused by the parasite itself but are the result of interaction of mechanical, immunologic, and humoral components. P. falciparum-infected erythrocytes impair microcirculation and cause hemolysis. Glycosylphosphatidylinositol moieties covalently linked to the surface antigens of falciparum malarial parasites appear to act like endotoxin. Glycosylphosphatidylinositol, via CD14, which is a receptor on monocytes, stimulates monocytes to release tumor necrosis factor, which in turn enhances synthesis of various cytokine cascades and mediators. Besides contributing to ARF, these mediators also cause changes in blood volume status. The degree of vasodilatation caused by vasodilating mediators varies with the severity of infection. Increased vascular permeability by the mediators occurs in severe infection, which results in hypovolemia and contributes to ARF. Although the cornerstone of treatment of malaria still is antimalarial drugs, several new modalities of treatment targeting toxin, signal transduction, mediators, and cytokines have great potential.

Acute Kidney Injury↗
PubMed1998

Venomous snakebite in Thailand. I: Medically important snakes.

Thailand has an abundance of venomous snakes. Among the neurotoxic family Elapidae, there are three species of the genus Naja (cobras), three of the genus Bungarus (kraits), and the king cobra of the genus Ophiophagus. Other Elapidae snakes in Thailand include sea snakes and Asian coral snakes of the genus Calliophis. They have potent venoms but rarely bite humans. Tissue and hemotoxic snakes are represented by family Viperidae, subfamilies Viperinae and Crotalinae. They remain an occupational hazard for farmers and rubber tappers, causing serious morbidity but only rare deaths, since competent treatment is now widely available throughout Thailand. Purified equine antivenin is manufactured locally for the monocled and Siamese spitting cobras (Naja kaouthia and N. siamensis), king cobra (Ophiophagus hannah), banded krait (Bungarus fasciatus), most green pit vipers (Trimeresurus sp.), Malayan pit viper (Calloselasma rhodostoma), and the Siamese Russell's viper (Daboia russelli siamensis).

Animals↗
PubMed1998

Venomous snakebite in Thailand. II: Clinical experience.

We reviewed a total of 2,525 snakebite patients in Bangkok. Of these, 1,415 were bitten by venomous snakes, 91 by neurotoxic snakes of genus Naja or Bungarus and 1,324 by snakes of family Viperidae or Crotalidae. Seventy-one percent of bites were on the lower extremity. There were two fatal cobra bites; both patients were dead on arrival at the hospital. Bites from vipers caused morbidity but no deaths. Species-specific antivenins are effective in reversing respiratory failure from cobra bites and coagulopathies from bites by Viperidae and Crotalidae snakes. However, early respiratory and wound care will save lives even in the absence of specific cobra and krait antivenin. Care of a snakebite victim should consist of immobilization and bandaging of the bitten limb with elastic bandages during transport to the hospital, early surgical debridement of necrotic tissue, appropriate infusion of antivenin, aggressive respiratory support, management of shock and infection, and peritoneal dialysis or hemodialysis. Incision of bite wounds, suctioning, application of ice, and tourniquets are of no proven value and may be dangerous. All snakebite victims in southeast Asia should survive if they receive early competent care.

Adult↗
PubMed1998

Efficacy and cross reactivity of Thai green pit viper antivenom among venoms of Trimeresurus species in Thailand and Japan.

The efficacy of the Thai green pit viper antivenom to neutralize lethal, hemorrhagic, and enzyme activities of Trimeresurus venoms was examined using venoms of Trimeresurus albolabris, T. macrops, and T. flavoviridis (Japanese Habu). Antivenom against Japanese Habu venom was also used to study immunological cross reactivity among Trimeresurus venoms. Thai green pit viper antivenom was comparably effective to Habu antivenom to neutralize all activities. Distinct cross neutralization was demonstrated indicating the presence of genus specific protection by Thai and Japanese Trimeresurus antivenoms. Results of immunoblotting analyses indicated that Thai and Japanese Trimeresurus venoms contain many cross-reactive protein components.

Animals↗
PubMed1998

Effects of Russell's viper venom on human erythrocytes in vitro.

The effects of Russell's viper venom (RVV) on human erythrocytes were studied in vitro with respect to packed cell volume (hematocrit), the erythrocyte morphology, and the effect of antivenom. Venom at various dosages ranging from 50 ng to 120 micrograms increased hematocrit significantly. The maximal effect was detected at 800 ng of venom. The biconcave erythrocytes shown by scanning electron microscopy became sphero-echinocytes. Such altered morphology was observed immediately at 1 minute and reached maximum at 30 minutes. The mild degree of erythrocyte deformation was observed at 60 and 120 min with 100 ng of RVV. There were no morphologic changes when ethylenediaminetetracetate (EDTA) was used as an anticoagulant or when plasma was substituted by isotonic saline, acetar, albumin added acetar solution. Phospholipase A2 at equivalent dose as compared to the venom could also produce the sphero-echinocytosis. The phospholipase A2 inhibitor, p-bromophenacyl bromide markedly reduced the degree of RVV induced sphero-echinocytosis. Verapamil, a phenylalkylamine calcium channel blocker, could not prevent the RVV induced sphero-echinocytosis. Although antivenom could not reverse the RVV induced sphero-echinocytosis, it minimized these effects. The RVV induced sphero-echinocytosis is likely caused by phospholipase A2. Calcium and some plasma factors are required for this process. Early treatment with antivenom plays some role in prevention of RVV induced sphero-echinocytosis which may reduce hypoxic cell injury.

Animals↗