Biomedical subjects
Publications and source records attributed to P Suresh.
The aqueous extract of the Cocculus hirsutus aerial parts (100 and 200 mg/kg, p.o.) showed significant diuretic activity and laxative effect in rats. The acute toxicity, orally evaluated in mice, was found to be higher than 3000 mg/kg.
PURPOSE: To evaluate the effectiveness and efficiency of an algorithm in the prevention of ocular surface disease in sedated and unconscious patients in the intensive care unit (ICU). METHODS: The eyes of all sedated and unconscious patients admitted to an ICU between September and December 1998 were managed according to an eye care algorithm. The applications of the preventive measures were assessed by a single observer twice weekly. The lid position, the presence and degree of keratopathy, sedation score, and the treatment received were documented at every assessment. RESULTS: Thirty-four patients were recruited for management according to the eye care algorithm over a period ranging from 1 to 28 days. Four patients were excluded because of failure by staff to adhere to the protocol. In 18 patients no active treatment was required. Out of six patients who had conjunctival exposure and were given ocular lubricants, four maintained clear corneas. No corneal or conjunctival staining was noted in two of the four patients whose lids required closure with Micropore tape for corneal exposure. Use of lid taping and lubricants prevented corneal abrasion in two patients who were prone ventilated. The prevalence of ocular surface abnormalities was 8.7 % where the algorithm was properly followed (23 patients). CONCLUSION: The proposed eye care algorithm appears to be effective in preventing ocular surface abnormalities in the sedated and unconscious patients in the ICU, and efficient in that it may reduce the workload required for critically ill patients.
Olanzapine is a novel antipsychotic effective in reducing positive and negative symptoms of schizophrenia and with a safe side-effect profile. Premarketing trials, however, included only a few elderly patients. Further data are needed regarding the effects of olanzapine in the elderly and those with comorbid medical illness. In this pilot study, 11 hospitalized patients (age range 60-85 years) who manifested symptoms of psychosis related to schizophrenia and schizoaffective disorders were treated with olanzapine (dose range, 5-20 mg/day). Efficacy and safety were assessed by the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale (CGI), Extrapyramidal Symptom Rating Scale (ESRS), Mini-Mental State Examination (MMSE), Calgary Depression Scale For Schizophrenia (CDSS), EKG, physical examination, and various laboratory tests. Seven patients responded to treatment and all of them showed improvement in both positive and negative symptoms, with greater reduction in positive symptoms. Treatment was discontinued in 2 patients whose symptoms showed no improvement or worsened. The CGI showed significant improvement in 9 patients, remained the same in 1, and worsened in 1 patient. ESRS showed significant reduction from baseline to final visit. Of the 10 patients who cooperated for MMSE, 9 had improved scores. The CDSS showed significant reduction in scores from baseline to final visit. No significant changes were noted in laboratory tests, prolactin levels, EKG, and physical examination. Concomitant administration of lorazepam, carbamazepine, divalproex sodium, and lithium carbonate caused no adverse consequences. The reduction of positive and negative symptoms, lack of significant extrapyramidal symptoms and other side effects, and lack of any significant drug interaction suggest that olanzapine may be a safe and effective antipsychotic medication in the elderly.
Thyroid function abnormalities have been associated with psychiatric illness. Even though it is a common practice to assess thyroid function in geropsychiatric patients, a literature search for the past 10 years did not reveal any published studies of assessments of thyroid function abnormalities in acute geropsychiatric populations. A retrospective chart review of 197 acute geropsychiatric inpatients and 14 comparison group patients showed that 40 geropsychiatric patients and 2 comparison group patients had abnormal thyroid function tests (TFfs). The most common abnormality was elevated triiodothyronine uptake (T3U), which was noted in 19 female and 13 male geropsychiatric patients. The difference in the prevalence of TFT abnormalities between the geropsychiatric patients and the comparison group subjects was not statistically significant. Both T3U and free thyroxine index (FTI) were significantly higher in the female geropsychiatric patients than in the female comparison group patients. The abnormalities in T3U and FTI in this study group may be related to an increased prevalence of unidentified systemic illness or to the presence of chronically poor nutrition.
AIM: To report the clinical consequences of contamination of human donor corneas by herpes simplex virus (HSV) in organ culture. METHODS: Two patients without previous history of ocular HSV infection underwent penetrating keratoplasty (PK), one for keratoconus and the other for Fuchs' endothelial dystrophy. One patient suffered primary graft failure while the other developed a persistent epithelial defect, ultimately resulting in graft failure. Viral culture of swabs taken from both corneas during the early postoperative period was undertaken. The failed donor corneas were examined histopathologically by immunohistochemistry (IHC) for HSV-1 antigens, transmission electron microscopy (TEM), and by polymerase chain reaction (PCR) for HSV DNA. Both failed corneas were replaced within 6 weeks of the initial surgery. The records of the fellow donor corneas were also examined for evidence of infection. RESULTS: HSV was cultured from both corneas during the early postoperative period. Histology of both donor corneas demonstrated a thickened corneal stroma with widespread necrosis of keratocytes and loss of endothelial cells. IHC showed keratocytes positive with antibodies to HSV-1 antigens. TEM demonstrated HSV-like viral particles within degenerating keratocytes. PCR performed on the failed corneal grafts was positive for HSV-1 DNA, whereas PCR performed on the excised host corneal buttons was negative in both patients. Records of the fellow donor corneas showed that one cornea was successfully transplanted into another recipient after 18 days in organ culture, whilst the other was discarded because of extensive endothelial cell necrosis noted after 15 days in organ culture. CONCLUSION: HSV within a donor cornea may cause endothelial destruction in organ culture and both primary graft failure and ulcerative keratitis after transplantation. Endothelial necrosis of a donor cornea in culture also raises the possibility of HSV infection within the fellow cornea.
BACKGROUND AND PURPOSE: Cryptosporidium parvum establishes a parasitic relationship with epithelial cells of the intestine. Infection with this protozoan is resolved in the immunocompetent host, but persistent life-threatening infection develops in the immunocompromised host. We propose that gammdelta T cells in the intestinal mucosa play a role in immunity to C. parvum. METHODS: Intestinal intra-epithelial lymphocyte and lamina propria T-cell subsets were examined in mice infected with C. parvum. The mice are homozygous for a deletion of the TCRalpha chain gene, TCRalpha(-/-) and, therefore, lack conventional alphabeta T cells, but retain a population of T cells with gammadelta T-cell receptors. To examine the contribution of gammadelta T cells to immunity, these mice were treated with monoclonal antibody GL3-3A, specific for this T-cell receptor, then were inoculated with C. parvum oocysts. Lymphocyte subsets and hematoxylin and eosin (H&E)-stained intestinal sections from untreated mice were compared with those from mice treated with either a low dose of GL3-3A for 6 weeks, or a high dose of GL3-3A for 16 weeks. RESULTS: The proportion of gammadelta T cells in the lamina propria increased in infected mice. In mice treated with a low dose of GL3-3A, a population of gammadelta T cells that had characteristics of activated cells, was still evident 6 weeks after inoculation. No C. parvum developmental forms were identified in the intestinal sections of mice under these conditions. However, TCRalpha(-/-) mice treated with a high dose of GL3-3A were depleted of gammadelta T cells, and 50% of the mice were infected with C. parvum. CONCLUSIONS: The gammadelta T cells contribute to protection against C. parvum infection. In the absence of conventional T cells, activation of intestinal gammadelta T cells may prevent infection with this organism.
There is paucity of published data regarding controlled trials with risperidone and olanzapine in elderly psychotic patients. Medical records of 151 hospitalized geropsychiatric patients (risperidone patients n = 114 and olanzapine patients n = 37) were analyzed for demographic data, target symptoms, doses, effects, side effects, comorbid medical conditions and concurrent medications. The mean age of the patients was 71 years. The male: female ratio was essentially the same for both groups. The mean daily dose was 3 mg for risperidone and 10 mg for olanzapine. 78% of the risperidone group and 75% of the olanzapine group appear to have responded to treatment. The discontinuation rates of medication was the same in both groups (22%). Adverse events were reported in 16-17% in both groups. It appears from this study that both risperidone and olanzapine are relatively safe and effective in geropsychiatric patients with comorbid medical illnesses. Controlled studies and head-to-head comparison studies are recommended.
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PURPOSE: To assess the prevalence and natural history of ocular surface disease in patients in an intensive care unit (ICU) and to identify any predisposing factors in order to improve eye care management protocols. METHODS: The eyes of all patients admitted to an ICU between February and May 1998 were examined at least weekly. The eyelid position, presence of conjunctival oedema, degree of keratopathy and sedation score were documented at every assessment. RESULTS: Twenty-six patients in an ICU were followed throughout their stay, which ranged from 3 days to 10 weeks. Eleven patients (42%) had some degree of keratopathy, which was detected in the majority in the first week of their stay. The presence of ocular surface disease was closely correlated with the degree of lagophthalmos, which in turn is closely related to the depth of sedation or paralysis. CONCLUSIONS: In this first ever longitudinal study it was found that assessment of lid position in ICU patients is the single most important observation to be carried out. A management algorithm derived from this evidence is based on daily observation and selective lid taping and shows encouraging early results.
Previous control studies carried out in children showed that respiratory infection alters riboflavin metabolism and leads to excessive urinary losses of the vitamin. In order to understand the nature of biochemical changes in riboflavin metabolism during respiratory infection, a study was carried out using the mouse as the experimental model, and Klebsiella pneumoniae as the infective organism. Mice were fed on either a low (0.5 mg/kg)- or high (13.3 mg/kg)-riboflavin semi-synthetic diet. Infection resulted in a 5-6-fold higher excretion of riboflavin in the urine of mice fed on the low-riboflavin diet. Higher erythrocyte FAD levels and lower liver FAD levels were also observed during infection. Of the four enzymes involved in the synthesis and breakdown of the flavin coenzymes studied, the activity of hepatic flavokinase (ATP: riboflavin 5'-phosphotransferase; EC 2.7.1.26) was significantly lower, and that of FAD synthetase (ATP: FMN adenylyltransferase; EC 2.7.7.2) was higher during riboflavin restriction and infection. The activity of FMN (acid) phosphatase (EC 3.1.3.2) was unchanged, whereas FAD (nucleotide) pyrophosphatase (EC 3.6.1.9) activity was significantly higher both with the low-riboflavin diet and during infection. Thyroid hormone is known to modulate flavokinase activity and, hence, thyroid status was assessed. Plasma triiodothyronine (T3) levels were not affected, but thyroxine levels were lower in the mice fed on the low-riboflavin diet. However, plasma T3 was significantly lower during infection, suggesting a mechanistic role for the hormone in the reduction of flavokinase activity.
Three methods of isolating Cryptosporidium parvum oocysts from rat feces were evaluated. Oocysts were initially isolated by sucrose density gradient centrifugation. They were further purified by passage through a glass bead column or a Percoll gradient or by dialysis. Although oocysts recovered from the glass bead column and by dialysis were relatively free of fecal debris, only oocysts recovered from the Percoll gradient were free of bacteria. Recovered oocysts retained their antigenicity and infectivity. The ability to effectively recover oocysts from rat feces suggests that the laboratory rat may be a convenient substitute for ruminants in the propagation and maintenance of C. parvum oocysts for in vitro and in vivo use.
This study was conducted to detect the effect of parenterally administered immunoglobulin isotype G (IgG) on the colonization and clearance of Bordetella avium at the tracheal surface in young turkeys. In two separate experiments, 3-week-old turkeys were infected with B. avium either after or before IgG administration. Comparisons were made between a control group which received an irrelevant IgG (specific for keyhole limpet hemocyanin [KLH]) and the experimental group which received a B. avium-specific IgG. When given before the bacteria, IgG reduced the numbers of colony-forming units (CFUs) in the trachea. As a supplement to non-specific respiratory defense mechanisms, B. avium-specific IgG also appears to inhibit colonization of the tracheal mucosa. In a second experiment designed to study the role of IgG in bacterial clearance, administration of B. avium-specific IgG after bacterial inoculation significantly reduced the number of CFUs on the tracheal surface. These studies support the role of B. avium-specific IgG in resistance to and recovery from B. avium infection.
The effects of Klebsiella pneumoniae infection on red blood cell and liver riboflavin levels and a few flavin enzymes were examined to verify our earlier hypothesis based on human experience that upper respiratory infections result in mobilization of riboflavin from tissues into blood, resulting in a rise in red blood cell riboflavin and an increased saturation of erythrocyte glutathione reductase (EGR) with its coenzyme flavin adenine dinucleotide (FAD; reduction in EGR activation coefficient, AC, values). Thirty-six-day-old male mice fed a diet marginally sufficient in riboflavin were injected with a single sublethal dose of K. pneumoniae. Batches of control, deficient infected and deficient uninfected animals were killed during the peak period of infection and after recovery. Infection brought about a significant rise in basal EGR activity due to greater saturation with coenzyme FAD and a concomitant reduction in EGR-AC values. On recovery, basal EGR activity decreased, and EGR-AC values increased to levels beyond control values, suggesting riboflavin deficiency. In the liver, acyl-coenzyme A dehydrogenase showed a significant decrease and pyridoxamine-phosphate oxidase activity a significant increase. Both the enzymes normalized after recovery. D-amino acid oxidase activity did not change.
Unilateral focal areas of intense, increased renal uptake of Tc-99m oxidronate sodium (technetium-99m HDP) were incidentally detected in the bone scan of a female patient who subsequently gave a history of recent trauma to her flank. Increased renal parenchymal uptake of Tc-99m HDP in this patient was thought to be due to kidney contusion. The case is interesting in itself and for its possible implications regarding the use of radio-labeled phosphate compounds for detection of renal contusion.
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Three-week-old turkeys were injected intravenously with Bordetella avium-specific immunoglobulin G (IgG), and absorbance readings were measured in blood, tracheal washings, and lacrimal secretions using an enzyme-linked immunosorbent assay at various time intervals. IgG was detected in tracheal and lacrimal secretions as early as 5 minutes after injection and peaked at 10 minutes after injection. Thereafter, IgG absorbance declined rapidly, reaching background levels by 24 hours. The absorbance readings of IgG in all three sites were comparable at all times from 10 minutes to 24 hours after administration. The results indicated that movement of IgG from blood to mucosal surfaces in turkeys occurs rapidly.
Antibody response to Bordetella avium was measured in serum and mucosal secretions of experimentally infected turkeys. Two-day-old turkeys were inoculated with B. avium, and four inoculated turkeys and four uninoculated control birds per trial were euthanatized weekly from 1 through 8 weeks postinoculation (PI). Maternal antibody of the IgG isotype, present in all 2-day-old birds sampled, decreased to background levels by 3 weeks of age. Antibody (IgG, IgM, IgA) was detected in serum, tracheal washings, and lacrimal secretions in response to B. avium infection. Regardless of the sample site and isotype, antibody levels peaked at 4-6 weeks PI and then decreased rapidly from 6 to 8 weeks PI. In general, IgM and IgA levels peaked earlier (4-5 weeks PI) but declined more rapidly than IgG levels. Numbers of B. avium in the trachea peaked at 2-3 weeks PI and then decreased rapidly from 4 to 8 weeks PI. Even though no direct causal relationship could be determined, the results indicate that an increasing level of antibody in serum, tracheal washings, and lacrimal secretions is temporally associated with clearance of B. avium from the trachea.
The purpose of this study was to develop a rapid method to distinguish Bordetella avium from closely related Bordetella avium-like and B. bronchiseptica bacteria. A monoclonal antibody of the IgM isotype was produced in Balb/c mice against live B. avium strain 75. The monoclonal antibody, in the form of ascites fluid, was added to a bovine serum albumin-glycine buffer (pH 8.6) and adsorbed to 3.03-microns-diameter latex beads. Optimum concentrations of antibody, beads, and bacteria were determined. The latex bead conjugate was tested against 40 isolates of B. avium, 24 isolates of B. avium-like bacteria, 17 isolates of B. bronchiseptica, two isolates of Alcaligenes faecalis, and several other common genera. Strong agglutination occurred with all B. avium isolates and the two isolates of A. faecalis. Weak agglutination occurred with Staphylococcus aureus and two isolates of B. bronchiseptica. There was no agglutination with any of the B. avium-like isolates. The latex bead agglutination test may be useful as an aid in the identification of B. avium when used in conjunction with other criteria.