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Biomedical subjects

M Rao

Publications and source records attributed to M Rao.

At least 199 records · Page 11Linked to original sources
PubMed1991

Screening for undescended testes.

There is a general consensus among surgeons and paediatricians that cryptorchidism should be detected and treated by the age of 5 years, if not earlier. In reality, incomplete descent is often detected well beyond the age of 5. The effectiveness of local screening was assessed by reviewing the screening history and subsequent management of boys treated for undescended testes between 1983 and 1986. The detection rates for undescended testes in the boys under 5 years were low both for doctors and health visitors. In contrast, the school entry medical examination for 5 and 6 year olds had a higher screening yield. Over 40% of cases came to light as a result of parents recognising the condition and seeking medical opinion. Late detection had also occurred in some boys who had had previous genital surgery or examination. Methods to improve early detection and ways of monitoring proposed changes are discussed.

Age Factors↗
PubMed1991

[Pathological and clinical features of primary ventricular hemorrhage due to moyamoya disease].

The clinical and pathological features of 20 cases of moyamoya disease complicated with primary intraventricular hemorrhage (PIVH) and verified by CT scanning, cerebral angiography and autopsy were reported. It seemed to the author that moyamoya disease appeared to be prone to cause PIVH, this hemorrhage being likely due to ischemic malacia in the ventricular wall. The tortuous, abnormal network vessels ruptured and bled as a result of infarction and damage of the walls of the miliary aneurysms. PIVH might be divided into two types: the panventricular hemorrhage and partial ventricular hemorrhage, according to the amount of blood that filled into the ventricles. 6 cases of the panventricular type were fatal. The symptoms were in conformity with the traditional concept of the most critical, intraventricular hemorrhage. The external ventricular drainage in combination with lumber puncture drainage would be the better way of treatment for these patients. 14 cases of the partial ventricular hemorrhage type showed the clinical features of acute subarachnoid hemorrhage (SAH). The treatment was similar to SAH too, and the prognosis was much better. It would be worth noting that moyamoya disease should be a factor not to be neglected in causing PIVH.

Adolescent↗
PubMed1991

Childhood asthma mortality: the Brooklyn experience and a brief review.

Pediatric asthma mortality is a perplexing and increasingly serious problem. Although many possible etiologic factors have been suggested, clear relationships are yet to be delineated. In addition to reviewing the literature, we studied the clinical and pathologic features of 14 local pediatric asthma deaths that occurred over a 7-year period. Thirteen of 14 children were African-American. Nine of 14 children (64.3) were older than 10 years of age, and 11 of 14 (78.6) were males. Based on a history of clinical features, 10 of the 14 children were characterized as severe asthmatics. Despite the fact that the majority of the children were regarded as severe asthmatics, only 1 of 14 had been evaluated with pulmonary function testing, and only 2 of 14 were receiving corticosteroids. Furthermore, only 2 of 14 were regarded as having good medical follow-up for their asthma. Ten of 14 children died suddenly secondary to asthma. One child was possibly abusing sympathomimetic inhalers, and none had evidence of toxic serum levels of theophylline. Six of 14 children (all adolescents) who died suddenly were negative on urine toxicology screening for cocaine, heroin, etc. Pathologic findings available for 10 children revealed mainly mucus plugging of the airways and collapse of various segments of the lungs, as well as pneumonia and pneumothorax in one child. In this group of children with sudden deaths (except for one child with pneumothorax), no other cause of death could be found.

Adolescent↗
PubMed1991

Laminarinase from Penicillium funiculosum and its role in release of beta-glucosidase.

An extracellular laminarinase (1----3)-beta-glucan glucohydrolase (EC 3.2.1.6) was purified from culture filtrates of Penicillium funiculosum. It was homogeneous on polyacrylamide gel electrophoresis in the presence and absence of sodium dodecyl sulfate. It had a Mr of 14,000 and isoelectric point of pH 4.2. The apparent Km value for lamimarinase was 8.3 mg/ml and Vmax was 8 mumol/min/mg. The distribution of beta-glucosidase activity in two different species of Penicillium showed that P. funiculosum had a higher ratio of extracellular to cell wall bound activity than Penicillium janthinellum. Treatment of mycelia of both species with NaCl, EDTA, Triton X-100, or proteolytic enzymes did not release the cell wall bound beta-glucosidase. Incubation of the mycelia with the laminarinase released 2-4 times more beta-glucosidase than the estimated cell bound activity in P. janthinellum and P. funiculosum.

Cell Wall↗
PubMed1990

Chemical modification of xylanases: evidence for essential tryptophan and cysteine residues at the active site.

N-Bromosuccinimide (NBS) completely inactivated xylanases from Chainia and alkalophilic and thermophilic (AT) Bacillus with a concomittant decrease in absorption at 280 nm and with second-order rate constants of 10,500 and 5000 M-1.min-1, respectively at pH 6.0 and 25 degrees C. The kinetic analysis of inactivation indicated that one and three tryptophan residues were essential for the xylanase activity from Chainia and Bacillus, respectively. The xylanases were also inhibited by 2-hydroxy-5-nitrobenzyl bromide (HNBB). The modification of cysteine residues by p-hydroxymercurybenzoate (PHMB) and N-ethylmaleimide did not cause a loss in activity of the xylanase from Bacillus, whereas that from Chainia was completely inactivated. The kinetics of inactivation revealed the involvement of one cysteine residue for xylanase from Chainia with a second-order rate constant of 50,000 M-1.min-1. The PHMB-modified enzyme failed to show the presence of titrable -SH groups. Xylan afforded complete protection against inactivation by NBS, HNBB and PHMB, indicating the involvement of tryptophan and cysteine residues at the substrate-binding region of the enzyme.

Bacillus↗
PubMed1990

Seroepidemiologic evaluation of anti-toxic and anti-colonization factor immunity against infections by LT-producing Escherichia coli in rural Bangladesh.

To evaluate serologic immunity against clinical infections by heat-labile enterotoxin-producing Escherichia coli (LT-ETEC) in rural Bangladesh, 124 children and adult women with LT-ETEC diarrhea (cases) were compared with 347 age-matched community controls. In paired acute-convalescent sera from the cases, IgG anti-CFA I and anti-CFA II antibody titers increased eight-to ninefold after infection by LT-ETEC with the homologous CFA, and IgG anti-LT antibody titers increased fourfold for all LT-ETEC infections. Anti-CFA and anti-LT titers peaked in controls aged 12-23 months, the age group with the highest incidence of ETEC infections. However, antibody titers were similar in acute sera from cases and in sera from controls. Although serum IgG anti-CFA and anti-LT antibodies rose in response to LT-ETEC infections and paralleled the age-specific incidence of ETEC in the community, these antibodies were not associated with a lower risk of LT-ETEC diarrhea.

Adolescent↗
PubMed1990

Infective endocarditis due to Streptococcus sanguis I occurring on a normal mitral valve.

We report a 64 year old lady in whom infective endocarditis of the mitral valve occurred with no previous underlying heart disease. Streptococcus sanguis I was isolated on blood culture and 2-D echo cardiography showed a vegetation on the anterior mitral leaflet. The viridans group of streptococci are classically associated with subacute endocarditis occurring on structurally abnormal valves, but involvement of a normal valve by these organisms is rare.

Echocardiography↗
PubMed1989

Molecular structure and expression of the murine lymphocyte low-affinity receptor for IgE (Fc epsilon RII).

The cDNA encoding the murine low-affinity receptor for IgE (Fc epsilon RII) has been isolated from a cDNA library prepared from B cells activated with lipopolysaccharide and interleukin 4. It encodes a 37-kDa protein of 331 amino acids with two potential N-linked glycosylation sites. Analogous to its human counterpart, there is no signal sequence and the putative transmembrane region is close to the amino terminus, indicating an inverse membrane orientation with the carboxyl terminus at the cell exterior. The predicted murine Fc epsilon RII amino acid sequence demonstrates a 57% identity with its human counterpart. The murine sequence has an additional internal repeat motif of 21 amino acids giving four repeats as compared to three in the human sequence. Furthermore, the murine Fc epsilon RII is truncated at the carboxyl terminus and the Arg-Gly-Asp sequence, a common recognition site of integrin receptors, which is found in the reverse configuration in human Fc epsilon RII, is missing. B cells activated with interleukin 4 and lipopolysaccharide have an increased amount of Fc epsilon RII mRNA as compared with resting or lipopolysaccharide-stimulated B cells. Con A-activated normal T cells, the TH-2 cell line D10, as well as the macrophage cell line J774 have no detectable Fc epsilon RII mRNA. Expression analysis using transiently transfected COS cells revealed that recombinant murine Fc epsilon RII binds anti-Fc epsilon RII as well as mouse and rat IgE but does not bind human IgE or mouse IgG. Fc epsilon RII expressed in COS cells has a molecular mass of 45 kDa whereas the Fc epsilon RII from B-cell lines is a 49-kDa protein.

Amino Acid Sequence↗
PubMed1988

Superinduction of low affinity IgE receptors on murine B lymphocytes by lipopolysaccharide and IL-4.

Recent work in both the human and murine systems has demonstrated that IL-4 is capable of specifically inducing the synthesis of the low affinity receptor for IgE (Fc epsilon RII). In addition, in conjunction with LPS, IL-4 will induce IgG1 and IgE synthesis. To analyze the correlation between Fc epsilon RII induction and IgE secretion, Fc epsilon RII and IgE levels were measured by RIA on murine splenic B cells stimulated with LPS and IL-4 over 7 days of culture. Treatment with LPS and IL-4 gave a 20- to 50-fold (day 3) "superinduction" of Fc epsilon RII levels compared with a 3- to 5-fold induction with IL-4 alone; removal of IL-4 resulted in a rapid decline in Fc epsilon RII levels. The cells expressing high Fc epsilon RII levels were determined to be blasts. Superinduction of Fc epsilon RII occurs at 10 U/ml IL-4 and remains relatively constant in the range of 10 to 1000 U/ml. In contrast, with increasing IL-4, IgE levels increase, reaching microgram levels at day 7 with 300 U/ml IL-4. Triggering the cells with anti-Ig, as expected, gave no Ig secretion, and in addition, Fc epsilon RII superinduction by IL-4 and anti-Ig was not seen. PMA is known to block Ig secretion induced by LPS. Concentrations of PMA that totally abrogated IgE secretion had no effect on Fc epsilon RII superinduction, indicating that the latter phenomena can be separated from IL-4-induced Ig secretion. Superinduction also results in higher levels of Fc epsilon RII fragment release into the media. Thus, attempts were made to influence IgE secretion by adding additional purified Fc epsilon RII fragment to the culture. The purified fragment did not have a significant influence on IgE levels in this system.

Adjuvants, Immunologic↗
PubMed1988

Induction and catabolite repression of cellulase in Penicillium funiculosum.

The regulation of endoglucanase synthesis in Penicillium funiculosum is investigated using a method based on the viscosity lowering effect on carboxy methyl cellulose (CMC) by endoglucanase. Cellobiose (1 mg/L) causes induction, whereas glucose (5 g/L) does not repress the enzyme formation. Lactose (5 g/L) has no effect on the synthesis of cellulase. Avicel and cellulose powder (CP) are the best inducers of cellulase and xylanase activity. Both endoglucanase and xylanase activity were induced by CMC, whereas xylan induced only xylanase activity. The effect of protease on induction of cellulase activity is discussed.

Caseins↗
PubMed1988

Mode of action and synergism of cellulases from Penicillium funiculosum.

A 1,4-beta-D-glucan cellobiohydrolase (EC 3.2.1.91) and 1,4-beta-D-glucan glucanohydrolase (EC 3.2.1.4) were purified from the culture filtrates of Penicillium funiculosum by using preparative isoelectric focusing. Both the enzymes were homogeneous on polyacrylamide gel with and without sodium dodecyl sulphate. The mol wt of the cellobiohydrolase and endoglucanase were 14,400 and 25,000 respectively. The purified enzymes were free of beta-glucosidase activity. Acting in isolation, the cellobiohydrolase had little capacity for solubilizing Avicel or Walseth cellulose, but showed increased rates of hydrolysis when combined with endoglucanase. Cellobiose inhibition (50%) was observed in the initial rate of the hydrolysis of Walseth cellulose. It was also observed that cellobiohydrolase initiates the attack on crystalline cellulose.

Cellulase↗