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Biomedical subjects

V Sitprija

Publications and source records attributed to V Sitprija.

At least 55 records · Page 3Linked to original sources
PubMed1997

Cross-neutralization of Thai cobra (Naja kaouthia) and spitting cobra (Naja siamensis) venoms by Thai cobra antivenom.

The neutralizing capacity of antivenom prepared against Thai cobra (Naja kaouthia) venom was compared in mice using the homologous venom and that of spitting cobra (Naja siamensis). The amounts of antivenoms neutralizing a dose of 4 LD50 of the test venom were determined. Four antivenom preparations were used: three purified antivenoms and a crude antivenom, which were made using N. kaouthia venom only. Almost the same neutralizing capacity was obtained with the purified antivenoms, whereas a slightly lower capacity was seen with the crude antivenom. However, ratios of the amounts of four antivenoms neutralizing the homologous and heterologous test venoms were almost constant. These results indicated that Thai cobra antivenom possesses neutralizing capacity against spitting cobra venom.

Animals↗
PubMed1997

Glomerular endothelial dysfunction determines disease progression: a hypothesis.

A glomerular endothelial function with its hemodynamic impact is proposed to determine disease progression. In the clinical settings associated with an intact endothelial function, such as minimal-change steroid-sensitive nephrosis, the early phase of diabetes mellitus and the early stage of an experimental model of renal ablation in animals, it was observed that adequate renal perfusion correlates with the intact structure and function of the nephron with no evidence of disease progression. In contrast, the clinical settings associated with endothelial dysfunction, such as chronic glomerulonephropathy, the late stage of diabetes mellitus and a renal ablation model in animals, are usually associated with a reduction in renal perfusion. The magnitude of renal hypoperfusion observed in all forms of chronic glomerulonephropathies is proportional to the degree of clinical severity. A progressive pattern of renal hypoperfusion is uniquely observed when disease severity progresses. In this context, a new therapeutic maneuver aiming to improve renal perfusion is proposed for treating glomerulonephropathy with disease progression and preventing it from developing to end-stage renal disease.

Animals↗
PubMed1997

Renal dysfunction in glomerulonephropathy associated with rapid onset renal failure.

Eight patients between the ages of 5 and 26 years developed a rapid decline of renal function with a period of oliguria or anuria which ranged between 1 and 21 days. The initial assessment of renal function revealed a severe degree of glomerular, tubular, and vascular abnormalities. The magnitude of the renal dysfunction was quantified and expressed in terms of a clinical score. The degree of glomerular and tubular dysfunction was inversely proportional to the renal plasma flow and peritubular capillary blood flow, respectively. Similar findings have been observed in a variety of other glomerulonephropathies where a relationship exists between the reduction of peritubular capillary blood flow and the severity of the tubulointerstitial disease. Evidence to support the position that the reduction of peritubular capillary blood flow plays a primary role in inducing tubulointerstitial disease is as follows: (i) A reduction of peritubular capillary blood flow has been documented in mesangial proliferative nephrosis with steroid resistance prior to the detection of tubulointerstitial disease. (ii) Ischemic insults are capable of inducing tubulointerstitial disease in the experimental setting of renal artery occlusion in animals. (iii) As demonstrated in the present report, an improvement of tubular function can be achieved following an increase in peritubular capillary blood flow with therapy designed to enhance renal perfusion.

Acute Kidney Injury↗
PubMed1997

Cell-mediated immunosuppression in mice by street rabies virus not restored by calcium ionophore or PMA.

It is known that rabies virus can suppress the host immune system. In this study we demonstrate a depression of cell-mediated immunity in mice, peripherally infected with Thai street rabies virus. The cell-mediated cytolysis of spleen cells from mice increased transiently on day 5 after infection and declined rapidly thereafter until death. The proliferation of spleen cells stimulated with a T-cell mitogen such as phytohemagglutinin or concanavalin A, was significantly suppressed during the course of infection. There was also a marked suppression of IL-2 secretion in parallel with a decrease of the T-cell proliferative response to mitogen. The suppression of T-cell proliferation was not restored by treatment with a calcium ionophore (A 23187) or phorbol 12-myristate-13 acetate (PMA).

Animals↗
PubMed1996

Heterologous antisera and antivenins are essential biologicals: perspectives on a worldwide crisis.

Active immunization against infectious disease is important. However, much of our world faces poverty, social injustice, and warfare, all of which cause universal immunization to remain a distant dream. Agents that provide passive immunity thus remain essential biologicals. The most important of these are human or equine antisera against rabies, tetanus, diphtheria, and snake antivenins. Homologous products are either unavailable or unaffordable in places where they are needed the most. Less expensive heterologous (equine) antisera can be purified and are safe to use, but these antisera are also in short supply. Monoclonal antibodies have been developed but are even less likely to be affordable in poor countries. Several traditional sources of equine antisera are becoming depleted as a result of economic disincentives; a poor reputation based on the high adverse reaction rates of the old, unpurified products; and the activities of animal rights activists who object to the use of horses as blood donors. Purified, pepsin-digested equine antisera are preferred; but developing countries sometimes are forced to make crude products that are less safe or have no specific therapy available at all.

Antivenins↗
PubMed1996

What is an acceptable delay in rabies immune globulin administration when vaccine alone had been given previously?

Rabies immune globulins (RIG) are not always available. Rabies-exposed patients often present to medical centers, particularly in canine rabies infested regions, after a vaccine series has been started without immune globulin administration. It is known that rabies immune globulin can result in suppression of the neutralizing antibody response which usually yields detectable antibodies by day 7. We have shown that it can be administered with a delay of up to 5 days after the start of vaccine treatment without significant antibody suppression within the first month. This study utilized the WHO approved multisite Thai Red Cross intradermal postexposure regimen. Effective use of rabies immune globulin in severe and multiple wounds, particularly in small children, may require dilution of the RIG in normal saline to provide a volume adequate for infiltration of all wounds.

Antibodies, Viral↗
PubMed1996

Low erythrocyte Na/K-pump activity and number in northeast Thailand adults: evidence suggesting an acquired disorder.

Healthy northeastern Thais have a higher erythrocyte sodium concentration and a lower erythrocyte membrane Na,K-adenosine triphosphatase (ATPase) activity than central Thais. To elucidate whether the defect is hereditary or acquired, we studied plasma sodium and potassium and erythrocyte sodium, potassium, Na,K-ATPase activity, and ouabain-binding sites (OBS) in the following groups: healthy newborns of ethnic central Thais (group 1), healthy newborns of ethnic northeast Thais (group 2), healthy adults of central Thailand ethnicity who lived in the rural central region (group 3) or in Bangkok (group 4), healthy adults of northeast Thailand ethnicity who lived in the rural northeast region (group 5) or who migrated to work in Bangkok for at least 1 year (group 6). Erythrocyte Na was higher in group 2 than in group 1. Group 3 had lower erythrocyte Na,K-ATPase activity than group 4, and it was lower in group 5 than in group 6. Among all groups, group 5 had the highest erythrocyte Na (11.6 mmol/L,F < 0.0001) and the lowest Na,K-ATPase activity (63 mmol Pi/mg x h, F < 0.0001) and erythrocyte OBS (397 sites per cell, F < 0.05) than the other adult groups. There was a positive correlation between erythrocyte Na,K-ATPase and erythrocyte OBS (r = .416, P < .0001). Multiple regression analysis demonstrated a correlation between erythrocyte Na as a dependent variable and erythrocyte OBS, plasma potassium, erythrocyte potassium, and erythrocyte Na,K-ATPase (r = .517, P < .0001). The erythrocyte Na,K-ATPase/OBS ratio, an expression of Na,K-ATPase activity equalized for the number of Na,K-pump units, was lowest among rural adults of the central region (group 3) and the northeast region (group 5) (F < 0.0002). Our data suggest that rural dwellers in Thailand tend to have lower erythrocyte Na,K-ATPase activity than urban dwellers and that this is probably acquired after birth. It was more severe among those from the northeast versus the central region, and was less severe among those who migrated to an urban area. This defect in northeast rural dwellers was probably associated with low numbers of Na,K-pump units and a defect of the pump to express activity, whereas in central rural dwellers it was probably associated with the latter condition. We postulate that there might be circulating Na,K-pump inhibitors and metabolic disturbances that cause attenuation of Na,K-ATPase function and synthesis in the northeast Thailand rural population, and that such substances may have an environmental origin. There may be a relationship between these abnormalities and sudden unexpected deaths.

Adult↗
PubMed1996

Failure of postexposure treatment of rabies in children.

Five failures of postexposure treatment of rabies in small children with multiple severe bites on the face and head are discussed. All had received rabies immune globulin and a potent tissue-culture vaccine. However, not all wounds had been infiltrated with immune globulin. Surgical closure prior to wound injection with immune globulin was performed in three cases. Another patient had wounds sutured after an intramuscular injection of immune globulin, without wound infiltration.

Animals↗
PubMed1996

Hypokalemia, high erythrocyte Na+ and low erythrocyte Na,K-ATPase in relatives of patients dying from sudden unexplained death syndrome in north-east Thailand and in survivors from near-fatal attacks.

The sudden unexplained death syndrome (SUDS) is a sudden death of unknown cause in healthy South-East Asians. In Thailand, it is common in the North-East region. We previously reported high incidences of low erythrocyte sodium and potassium-activated adenosine triphosphatase (Na,K-ATPase) activity and of high erythrocyte sodium in North-East Thais and speculated that this metabolic defect might be associated with the high incidence of SUDS in that region. In this communication, we studied plasma sodium and potassium, erythrocyte sodium and potassium, activities of erythrocyte Na,K-ATPase, ouabain-insensitive ATPase and total ATPase in healthy Thai blood donors from Central Thailand (group 1), healthy North-East city dwellers (group 2), relatives of SUDS victims (group 3) and survivors from SUDS-like attacks (group 4). Compared with groups 1 and 2, group 3 and 4 subjects had significantly lower plasma potassium (p < 0.0001), higher erythrocyte sodium (p < 0.0001), lower activities of erythrocyte Na,K-ATPase (p < 0.0001) and of erythrocyte total ATPase (p < 0.0001). In addition, group 4 subjects had lower plasma potassium, higher erythrocyte sodium and lower activity of total ATPase than those of group 3. The findings suggest that the pathogenesis of SUDS could be related to hypokalemia and a membrane sodium/potassium pump defect.

Adult↗
PubMed1996

Renal and systemic hemodynamics, in falciparum malaria.

Renal and systemic hemodynamics, plasma arginine vasopressin, plasma renin activity, plasma norepinephrine, blood volume and water loading test were studied in 10 patients with falciparum malaria without renal failure. Six patients responded to water load normally, while 4 patients had a decreased response to water load. The patients with a normal water load response had normal renal and systemic hemodynamics and a normal hormonal profile. The patients with a decreased response to water load had hyponatremia, hypervolemia, high cardiac index, low systemic vascular resistance, high plasma arginine vasopressin, high plasma renin activity, high plasma norepinephrine, low creatinine and p-aminohippurate clearances, low urine sodium and high urine osmolality. They had a lower mean arterial pressure during the acute phase of the disease than during the recovery phase. The findings suggest that a decreased response to water load is due to peripheral vasodilatation which results in a decreased effective blood volume leading to the release of vasopressin and norepinephrine, increased renin activity and decreased renal hemodynamics.

Adult↗
PubMed1996

Renal dysfunctions in glomerulonephropathy with rapidly declined renal failure.

Eight patients aged between 5 and 26 years developed rapid deterioration of renal function and became oliguric/anuric with duration ranging from 1 to 21 days. The initial functional assessment revealed severe degree of glomerular, tubular, and vascular dysfunctions. The magnitude of renal dysfunction was quantified and expressed in terms of a clinical score. The degree of glomerular and tubular dysfunctions were inversely proportional to the renal plasma flow and peritubular capillary blood flow (PTCB), respectively. Similar findings have been observed in a variety of severe glomerulonephropathies. In this aspect, it is likely that the reduction of peritubular capillary blood flow and tubulointerstitial disease are interrelated. Further evidence to support the primary role of reduction of PTCB in inducing tubulointerstitial disease is provided by the following: (a) Reduction of PTCB is documented in mesangial proliferative nephrosis with steroid resistance prior to the detection of tubulointerstitial disease. (b) Ischemic insult can induce tubulointerstitial disease in experimental setting of renal artery occlusion in animal, (c) Improved tubular function can be achieved following the increase in PTCB with the enhanced renal perfusion therapy.

Adolescent↗
PubMed1996

Maternal antibodies against rabies in Thai puppies. A preliminary study.

Serum antibodies to rabies virus were measured in 32 Thai puppies before primary vaccination. Only five showed evidence of rabies antibody by ELISA testing and they had no rabies virus neutralizing activity detectable by RFFIT. Immunologic ignorance of these young dogs leaves a large part of the canine population susceptible to rabies. This could be one reason for the failure of canine rabies control efforts in Thailand.

Animals↗
PubMed1996

Hepatitis virus and kidney.

Hepatitis A, B and C viruses are major causes of viral hepatitis in human. These infectious agents not only damage liver parenchyma but can also affect renal parenchyma. Hepatitis A virus could produce acute renal failure in a similar fashion to hepatorenal syndrome. Several lines of evidence have shown that chronic hepatitis B virus-infected patients could develop immune complex glomerulopathy. There are convincing data which incriminate hepatitis C virus as the proximate aetiology of certain forms of glomerulonephritis. In post-renal transplanted patients, hepatitis B and C virus could cause increased morbidity and mortality from chronic viral hepatitis. Whether renal transplantation should be performed, either as a donor or as a recipient, in subjects infected with hepatitis B or C virus, is still an issue of controversy.

Hepatitis A↗
PubMed1996

Comparison of separated-lymphocyte and whole-blood lymphocyte proliferation assays for evaluating rabies-induced cellular immunity.

A whole-blood lymphocyte proliferation assay was compared to a standard method requiring the isolation of peripheral blood mononuclear cells (PBMC). Both methods were used to measure the cell-mediated immune responses to rabies in rabies-vaccine recipients. Whole-blood cells gave moderately higher lymphoproliferative responses in terms of stimulation indices than did separated-PBMC. The results obtained from these two methods can be considered equivalent for the purpose of quantitating cellular reactivity to rabies. The use of whole blood has advantages over the standard isolated-PBMC method.

Immunity, Cellular↗
PubMed1995

Value of skin testing for predicting reactions to equine rabies immune globulin.

The high cost of postexposure prophylaxis for rabies is one reason that treatment is inadequate in developing countries. This problem has kindled interest in the use of equine rabies immune globulin, which is a less expensive, yet effective, substitute for human rabies immune globulin. Fatal anaphylaxis is a feared complication of the administration of heterologous serum; therefore, authoritative sources recommend prior skin testing. However, recommendations for methods of administering such a skin test and for its interpretation vary greatly. We embarked on a long-term study to develop guidelines for administration and interpretation of skin test results and to eventually determine a cost-benefit ratio. The skin test is not predictive of serum sickness. Anaphylaxis is rare with modern purified and pepsin-digested equine rabies immune globulins. We consider a skin test to be positive only if a wheal of > 10 mm in diameter, with or without flare, or a wheal of 5-10 mm in diameter with a flare of > 20 mm develops. Long-term studies will be required to answer the remaining questions regarding test criteria and cost benefits.

Adolescent↗