Severe cutaneous Mycobacterium chelonei infection following a yellow jacket sting.
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Biomedical subjects
Publications and source records attributed to S Kumar.
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To assess the effects of an LHRH analog (LHRH-ethylamide des gly10 D-Leu6) on the function of the cryptorchid testis, an animal model was created, using prepubertal male Sprague-Dawley rats (21 days old). The animals were divided into six groups: 1) sham operated; 2) sham + LHRH treated; 3) cryptorchid; 4) cryptorchid + LHRH treated; 5) cryptorchid and orchidopexed; 6) cryptorchid, LHRH treated and orchidopexed. Two weeks post cryptorchidism, the animals were treated with either saline or LHRH-analog (one microgram./rat/day) subcutaneously for a total of twenty five days. Orchidopexy was performed following hormonal treatment. The effects of treatment were assessed in terms of body and reproductive organ weights, serum testosterone and LH levels, sperm counts and motility and fertility. The results demonstrated that experimental cryptorchidism impaired reproductive function, which was restored by orchidopexy, alone. Treatment of cryptorchid rats (groups 4 and 6) with LHRH did not produce any lasting improvement in spermatogenesis or fertility.
Branchiootorenal syndrome is an autosomal dominant disorder that affects an estimated 2% of profoundly deaf children. In addition to hearing impairment, it is characterized by a lop-ear deformity, preauricular pits, branchial cleft sinus tracts, and renal anomalies. The pathogenesis of the disease remains unknown; however, the defective gene has been localized to chromosome 8q by family linkage studies.
Lipomatous tumours of the parapharyngeal space are rare. A case of lipoma of the parapharyngeal space is reported for its rarity, characteristic radiological findings, and effect on growth of the facial bones.
The results of single modality treatment using surgery or radiotherapy alone in advanced head and neck cancers are known to be unsatisfactory. The present study analyses 252 cases with stage III and IV resectable cancers of the head and neck region selected to be treated by a combined regime of pre- or post-operative radiation and radical surgery. Only 193 patients completed the treatment protocol. There were 58 cases (33.5 per cent) who failed either at primary or regional sites or both. Nine cases (five per cent) developed distant metastasis. Absolute and determinate four year disease-free survival was 55 per cent and 61 per cent respectively. Early lesions (stage I and II) have been excluded from the study. The study indicates that a reduction in primary and regional failures correlates well with a combined therapy, though prolonged treatment may affect patients' compliance to some extent.
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Entamoeba histolytica can reduce nitro-blue tetrazolium (NBT) in Hank's balanced salt solution to almost the same extent as in Eagle's minimal medium. Further, this reduction was stimulated only to a minor degree by glucose, pyruvate and DL-serine, substrates known to support respiratory activity (O2 uptake) in E. histolytica. However, both NADH and NADPH increased NBT reduction several-fold, the effect being greater with NADPH. A sizeable proportion of this endogenous dye-reducing capability (in Hank's solution) was associated with low-speed sediments obtainable from amoebic homogenates, which also shared the bulk of 125I labelling (when the homogenates were prepared after surface labelling with Na 125I). Conversion of the dye to formazan was strongly inhibited by -SH blocking agents, but was not influenced by rotenone and antimycin A. The activity was also inhibited by H2O2, but stimulated by catalase. Superoxide dismutase only slightly curtailed NBT reduction in intact cells, but inhibited it in homogenates in a concentration-dependent manner to a maximal extent of 33%. Almost the same degree of curtailment of this activity was induced by anaerobic conditions. Both concanavalin A (Con A) and phorbol myristate acetate stimulated the activity in intact cells, though the effect of Con A was nullified by alpha-methyl mannoside. Both NBT-reducing capability and alcohol dehydrogenase activities were higher in the more virulent IP:106 strain, and they increased with time in cultures of NIH:200 in a cholesterol-enriched environment.
Serious hepatotoxicity may develop in chronic alcoholics while they are taking therapeutic doses of acetaminophen. The mechanism of increased susceptibility involves induction of isoenzymes of the cytochrome P-450 system by alcohol and depletion of hepatic glutathione reserves, both of which can result from chronic alcohol ingestion and both of which affect the metabolism of acetaminophen. Chronic alcoholics with acetaminophen hepatotoxicity usually seek help after jaundice and clinical liver disease have already developed. At presentation, the blood acetaminophen level is often low or unmeasurable. Features that should immediately suggest acetaminophen hepatotoxicity in a chronic alcoholic include an aspartate amino-transferase level of more than 1,000 IU/L and, sometimes, a very long prothrombin time. The diagnosis can be distinguished from that of suicidal ingestion or alcoholic hepatitis by means of routine laboratory tests and a carefully taken history.
The binding characteristics of Hoechst 33258 (1), a synthetic bis-benzimidazole, and its structural analog 2, with one of the benzimidazoles replaced by a pyridoimidazole, to the self-complementary decadeoxyribonucleotide sequences d(CGCAATTGCG)2 (A) and d-(CATGGCCATG)2 (B) respectively, were examined using high field 1H-NMR techniques. Selective complexation induced chemical shift changes, the presence of exchange signals and intermolecular NOE contacts between the ligands and the minor groove protons of the oligonucleotides suggest the preferred binding sites as the centrally located AATT segment for complex A1, and the CCAT segment for complex B2. The B-type conformations of the two DNA duplexes are preserved upon complexation, as confirmed by the 2D-NOESY based sequential connectivities involving DNA base and sugar protons. Close intermolecular NOE based contacts between the ligands and their respective DNA sequences were further refined to model the ligand-DNA complexes starting from the computer generated B-type structures for the oligonucleotides. Force field calculations of ligand-DNA interaction energies indicate a more favorable contribution from the van der Waals energy component in the case of complex A1 consistent with its stronger net binding compared with the complex B2. Overall, the incorporation of a pyridinic nitrogen in Hoechst 33258 structure alters its selectivity for base pair recognition from A.T to G.C, resulting largely from the formation of a hydrogen bond between the new basic center and the 2-NH2 group of a guanosine moiety. The rates for the exchange of ligands between the two equivalent binding sites (AATT for 1, and CCAT for 2) of the self-complementary DNA sequences, are estimated from analyses of coalescence of NMR signals to be 189s-1 at 301 K for A1 and 79s-1 at 297 K for B2; which correspond to delta G++ of 13.8 and 18.6 kcal.mol-1 respectively.
Soluble chromium (VI) compounds either alone or in combination with 3-methylcholanthrene (MC) were used to transform non-tumorigenic osteoblast-like human osteosarcoma cells (HOS TE85). The Cr(VI) compounds were highly toxic to these cells with LC50 values in the range of approximately 0.5-1.0 microM. Continuous passaging of the treated cells resulted in sustained increase in anchorage-independent (AI) colony formation. Treatment with Cr(VI) and MC resulted in substantial increase in AI growth. At the XVth passage, a number of individual AI colonies were expanded in culture and used for further studies. The cells are refractory in appearance and grow as 'nests' rather than as monolayers. The cell lines have relatively high plating efficiency (PE) in soft agar and respond to promotional effect of phorbol-12-myristate-13-acetate by an increase in PE and in the size and number of AI colonies. While the isolated cells are not tumorigenic when tested in athymic nude mice, most of the lines possess higher levels of plasminogen activator (PA) activity, considered as one of the markers of transformation. This is also reflected in the increase in the steady state level of urokinase type PA mRNA. These results show that Cr(VI) compounds are capable of promoting human cells to an altered phenotype characteristic of a stage in the carcinogenesis cascade.
Branchio-oto-renal syndrome (BOR) is an autosomal dominant disorder with variable clinical manifestations affecting branchial, renal and auditory development. Varying clinical expression of the disease between different families suggests that multiple loci may be involved. However, the possibility of genetic heterogeneity as the cause of clinical variability cannot be resolved until the gene(s) causing BOR syndrome are mapped. DNA from four generations of a family with autosomal dominant BOR syndrome have been typed with a series of genetic markers on the long arm of chromosome 8. Using two point linkage analysis, a significant lod score of Z = 4.0 at theta = 0.05 was obtained with the D8S165 microsatellite marker. Multipoint analyses with 8q markers place the gene for BOR between the markers D8S87 and D8S165.
The objective of the study was to evaluate, using a prospective cohort study, whether classification of nutritional status by 'Z score' or per cent of reference median alters the prediction of death in malnourished children. The subjects were children with diarrhoea requiring hospitalization due to moderate or severe dehydration and/or associated complications. There were 382 participants under 5 years of age, of whom 37 died (cases), 320 were discharged in a satisfactory condition (controls) and 25 left before diarrhoea was completely cured (lost to follow-up--excluded). Rehydrated weight and recumbent length (under 2 years) or standing height were recorded and the three indices (weight for age, height for age and weight for height) derived as both 'Z scores' and per cents of reference National Centre for Health Statistics (NCHS) medians. Logistic regression, sensitivity specificity curves and Zda test for normalized distances were used to compare the relative utility of these two classification methods in identifying children with a high risk of dying. The per cent of reference median and 'Z scores' were highly correlated (r = 0.9540, 0.9787 and 0.9667, respectively). Both methods yielded virtually identical results in predicting death of malnourished children for all the three indices. It was concluded that 'Z score' and per cent classification of nutrition are equally efficient in predicting death of malnourished children.
In order to investigate the hypothesis that the spindle cells of Kaposi's sarcoma originate from dendrocytes, we stained 22 cases of cutaneous and extracutaneous Kaposi's sarcoma for the presence of factor XIIIa. We selected eight lesions from the skin, five from the oral mucosa, four from gastrointestinal mucosa, three from lymph nodes, and one each from esophagus and conjunctiva for this study. The majority of cutaneous and lymph node Kaposi's sarcoma lesions had a considerable number of dendrocytes admixed with the spindle tumor cells. Of the five oral mucosal lesions only three showed a focal presence of dendrocytes. No dendrocytes were observed in the lesions biopsied from the gastrointestinal mucosa, esophagus, and conjunctiva. Our findings suggest that the proliferation of dendrocytes seen within the lesions of Kaposi's sarcoma in the skin and lymph nodes probably represents a nonspecific host response in organs where they are normally present, and it is unlikely that they constitute the neoplastic cells of Kaposi's sarcoma.
We discuss the light-microscopic, immunohistochemical, electron-microscopic, and flow cytometric analysis in a case of invasive transitional cell carcinoma of the renal pelvis with rhabdoid features and glandular metaplasia. This tumor demonstrated in situ rhabdoid transformation of the transitional epithelium, which has not been described before. Electron-microscopic examination of the rhabdoid cells revealed whorled aggregates of intermediate filaments. There was also evidence of mucin-filled intracellular lumina on light and electron microscopy in both in situ and invasive components of the tumor. Our findings lend support to the view that tumors with "rhabdoid" features in adults and perhaps some children represent a heterogeneous group of neoplasms, some of which may just be unusual morphologic variants of a transitional cell carcinoma, in contrast to the distinct clinicopathologic entity of childhood renal rhabdoid tumors.
Dehydroepiandrosterone (DHEA), a C19 adrenal steroid hormone, induces peroxisome proliferation in liver cells and is hepatocarcinogenic in the rat. The present study deals with the phenotypic properties of DHEA-induced liver lesions. A majority of the altered areas (80-87%), neoplastic nodules (> 94%) and hepatocellular carcinomas (HCC, 80-100%) lacked the marker enzymes gamma-glutamyltranspeptidase and placental form of glutathione S-transferase (GSTP). Northern blot analysis of HCC from 4 rats revealed no detectable GSTP mRNA. These HCC, however, showed a marked decrease in the staining of glucose-6-phosphatase and adenosine triphosphatase. These results indicate that the phenotypic properties of liver tumors induced by DHEA and amphipathic carboxylate peroxisome proliferators are similar.
The residual repellent activity of N,N-diethylphenyl-acetamide (DEPA), N,N-diethyl-3-methyl benzamide (DEET) and dimethylphthalate (DMP) against the hard tick Rhipicephalus sanguineus (Latreille) and the soft tick Argas persicus (Oken) from topical application on rabbits and hens respectively in the laboratory have been studied. It was found that a 25% concentration of DEET gave strong repellency (greater than 90%) against larvae and nymphs of R. sanguineus for 15 and 7 days respectively and against A. persicus larvae and nymphs greater than 90% for 11 and 5 days respectively. Strong repellency (greater than 90%) against adults of the hard and soft ticks was observed for 9 and 7 days respectively with 40% DEET. DEPA at 25% concentration showed strong repellency (greater than 90%) against larvae and nymphs of R. sanguineus and A. persicus for 11 and 5 days respectively. Adults of hard and soft ticks were strongly repelled (greater than 90%) for 9 and 5 days respectively by 40% DEPA. DMP was found to be the least effective against all stages of both species of tick.
A comparative study of lectin binding to ensheathed (EnL3) and exsheathed (ExL3) L3 larvae of Necator americanus, Ancylostoma duodenale and Ancylostoma ceylanicum revealed a number of differences between these hookworm species. These differences could provide a novel approach to distinguish infective L3 larvae in field conditions. For example, binding of Ulex europaeus agglutinin (UEA) and Ricinus communis agglutinin (RCA120) to N. americanus EnL3 distinguished them from those of A. duodenale and A. ceylanicum. Furthermore, UEA and RCA120 negative EnL3 could be separated into the two Ancylostoma sps. tested, as Dolichos biflorus agglutinin and Soybean agglutinin bound to EnL3 of A. ceylanicum but not to those of A. duodenale.
A case of Sheehan's syndrome following eclampsia is presented. The clinical features were not recognised early probably because the condition was not suspected, being a rare sequel of eclampsia. Non availability of specialist care may have been partly responsible and is highlighted. Increased awareness of all possible aetiological factors in this condition is necessary for clinicians.