Biomedical subjects

U Singh

Publications and source records attributed to U Singh.

At least 73 records · Page 4Linked to original sources

PubMed1994

Clinico-haematological profile in acute and chronic Plasmodium falciparum malaria in children.

The clinicohaematological findings of acute state (Group A, 30 patients) and chronic state (Group B, 34 patients) of falciparum malaria in paediatric patients are compared. The children with chronic falciparum malaria were apyrexic and presented with features of moderate to severe anaemia with hepato-splenomegaly. Greater severity of anaemia and haemolysis, higher incidence and severity of neutropenia, atypical lymphocytosis, monocytosis and thrombocytopenia were observed in patients with chronic falciparum malaria as compared to patients with acute falciparum malaria despite lesser degree of parasitaemia in the former as compared to the latter. While mechanical destruction of parasitised RBC's, ineffective and dysplastic erythropoiesis either due to unmasking of border line dierty folic acid deficiency or otherwise, transient hypoplasia of bone marrow, impaired utilization of iron and immune destruction of RBCs with hypersplenism may be the mechanisms for anaemia, transient hypoplasia of bone marrow and hypersplenism may be the factors responsible for thrombocytopenia and neutropenia.

Acute Disease↗

PubMed1994

Clinical, hematological and electrophysiologic study of megaloblastic anemias.

Thirty one cases of megaloblastic anaemia were studied clinically and electrophysiologically. Eight patients had clinical evidence of peripheral neuropathy. MNCV, distal sensory latency, la fibre conduction velocity, proximal conduction velocity and H-reflex amplitude and latency were compared with fourteen age and sex matched healthy controls. MNCV, proximal conduction velocity and H-reflex amplitude were significantly decreased in anaemic subjects while distal sensory latency was increased. No change was seen in la fibre conduction velocity and H-reflex latency. There was no correlation between severity of anaemia and the electrophysiologic abnormalities. MNCV and la fibre conduction velocity improved after correction of anemia.

Adolescent↗

PubMed1993

Protein quality of pigeonpea (Cajanus cajan (L.) Millsp.) as influenced by seed polyphenols and cooking process.

True protein digestibility (TD), biological value (BV), and net protein utilization (NPU) of low-polyphenol pigeonpea cultivars (Nylon, BDN 2, and ICPL 87067) were significantly higher than those of the high polyphenol cultivars (C 11, ICPL 87, and ICPL 151) when whole-seed samples were compared. Most of the polyphenols (80-90%) were concentrated in the seed-coat. Dhal (decorticated split cotyledons) samples of low (Nylon) and high (C 11) polyphenol cultivars revealed no large differences in TD, BV, and NPU values of these cultivars. This indicated an adverse affect of seed-coat polyphenols on protein quality of pigeonpea whole-seed. The cooking process significantly increased TD in both whole seed and dhal samples. BV of both whole-seed and dhal samples was reduced remarkably by cooking. However, NPU of the cooked whole-seed and dhal samples was significantly higher than in the raw samples. No noticeable differences due to cooking were observed in amino acid composition of whole-seed and dhal samples of these cultivars.

Amino Acids↗

PubMed1993

Circanual variation of sperm count and motility in men.

Seasonal variation in rhythmicity of spermatogenesis might be due to external temperature fluctuation which could partially be responsible for decreased sperm counts in summer. Other factor like exposure to light might contribute for the reduction in sperm counts. These facts should be taken into account before diagnosing male fertility.

Adult↗

PubMed1993

Cephalosporins.

Explore the source record for details and available documents.

Bacterial Infections↗

PubMed1992

Site-specific frameshift mutagenesis by a propanodeoxyguanosine adduct positioned in the (CpG)4 hot-spot of Salmonella typhimurium hisD3052 carried on an M13 vector.

Malondialdehyde induces frameshift mutations in Salmonella typhimurium strain hisD3052. The ability of propanodeoxyguanosine (PdG), a structural analog of the major malondialdehyde-deoxyguanosine adduct, to induce site-specific frameshift mutations was tested in the (CpG)4 hot-spot of hisD3052 carried on an M13 vector (M13MB102). PdG was introduced at position 6248 of duplex M13MB102 by ligation of the oligonucleotide 5'-CGC(PdG)CGGCATG-3' into a heteroduplex containing an 11-nucleotide gap in the (-)-strand between the SphI and BssHII restriction sites and deoxyuridine in place of thymidine in the (+)-strand. Ligation proceeded with 70% efficiency, and closed circular duplex DNA molecules were isolated in 40% yield. The adducted genome was sensitive to cleavage by SphI but resistant to cleavage by BssHII. Transformation of Escherichia coli strain JM105 with adducted M13MB102 led to 25% reduced survival relative to unadducted M13MB102 and produced frameshift mutations in 2.5% of the progeny phage. All of the mutations were deletions, and 70% occurred by deletion of CpG. Unadducted genomes exhibited a 40-fold lower mutation frequency, and all the mutations were single-base deletions at the sites of ligation of the 11-mer. These results illustrate that PdG, a structural analog of the major malondialdehyde-deoxyguanosine adduct, induces frameshift mutations in M13MB102 and that single-stranded nicks are efficient premutagenic lesions in this recombinant bacteriophage.

Bacteriophage M13↗

PubMed1991

Peanut as a source of protein for human foods.

Peanut has traditionally been used as a source of oil; however, its worldwide annual protein harvest has reached nearly 4.5 million tons. India followed by China and the United States are the major producers of peanut. In recent years, several cereals and legumes-based foods using peanuts as protein supplements have been developed to alleviate protein calories-malnutrition problem. Peanut in the form of flour, protein isolates, and meal in a mixed product have been found to be very desirable from a sensory quality point of view. Peanut protein is deficient with respect to certain essential amino acids, but its true digestibility is comparable with that of animal protein. Even though various processing methods influence the nutritional and sensory quality of peanut fortified human foods available information on these aspects have been reviewed and summarised in this paper in order to optimize the utilization of peanut protein to increase protein value of cereal-based foods in developing countries of the peanut growing regions of the world.

Arachis↗

PubMed1991

Sulfhydryl-dependent attachment of Treponema denticola to laminin and other proteins.

Attachment of Treponema denticola ATCC 35405 to laminin, a major basement membrane protein, and to other proteins was studied. Microdilution plates were coated with the proteins, and the attachment of T. denticola was measured by the enzyme-linked immunosorbent assay technique. Compared with bovine serum albumin (BSA), T. denticola had a high affinity to laminin, fibronectin, fibrinogen, and gelatin, as well as to type I and type IV collagens. Attachment to RGD peptide (Gly-Arg-Gly-Asp-Ser, the integrin recognition sequence) was only about 30% of that to laminin and was comparable to attachment to BSA. Tests with laminin fragments obtained through elastase digestion showed that the spirochetes attached well to an A-chain 140-kDa fragment involved in eukaryote cell attachment but did not attach to a 50-kDa fragment that includes the heparin binding site. Pretreatment of T. denticola with soluble laminin, fibronectin, gelatin, BSA, or fibrinogen had no effect on the attachment of the bacteria to laminin or fibronectin. A wide variety of compounds were tested for their possible inhibitory actions on the attachment. While most treatments of T. denticola ATCC 35405 had little or no effect on the attachment to proteins, sulfhydryl reagents p-chloromercuribenzoic acid (pCMBA) and oxidized glutathione inhibited the attachment by 70 to 99%, depending on the protein. When T. denticola was first allowed to attach to proteins, addition of pCMBA or oxidized glutathione could no longer reverse the attachment. Heat treatment of the spirochetes also markedly reduced the attachment to laminin, gelatin, and fibrinogen but not to BSA. Mixed glycosidase treatment of the spirochetes inhibited the attachment by 20 to 80%. None of the above treatments of the substrate proteins had any marked effect on the spirochete attachment. The results indicate that T. denticola has the capacity to bind to many different kinds of proteins by utilizing specific attachment mechanisms. The binding appears to involve protein SH groups and/or carbohydrate residues on the surface of T. denticola.

Amino Acid Sequence↗

PubMed1991

Patterns of erythropoiesis and anaemia in leprosy.

A total of 128 leprosy patients were investigated for the morphological type of anaemia, the underlying disturbances in iron metabolism and patterns of erythropoiesis and other cytomorphological changes in the bone marrow. The anaemia was a mild to moderate degree in paucibacillary (PB) leprosy, while in multibacillary (MB) leprosy it was of a severe degree. Iron deficiency was observed in only a few patients. Impaired iron utilization as observed in a anaemia of a chronic disorder was a common finding in MB leprosy (41.7%) and more so in new cases (50%). Megaloblastic erythropoiesis was also more frequent in MB leprosy (45.2%) as compared to PB leprosy (16%), accounting for the severe degree of anaemia in the former type. In 17.2% of the total patients (MB, 21.4%; PB, 9%) both megaloblastic erythropoiesis and features of impaired iron utilization were observed in bone marrow. Disturbances in iron metabolism and erythropoiesis were also observed but to a lesser degree in patients receiving specific antileprosy treatment. Irrespective of the type of disease and duration of treatment, increasing frequency of acid-fast bacillia (AFB) positivity and granulomas was observed in the bone marrow with an increasing severity of anaemia.

Anemia↗

PubMed1991

Lipid-laden macrophages in bone marrow of leprosy patients.

While conducting a study to observe bone marrow cytomorphological changes in multibacillary leprosy, lipid laden macrophages as seen in sphingolipidoses were noted. The present study was planned to observe the occurrence and morphological characterization of these macrophages in various types of leprosy. Bone marrow records from 48 cases of paucibacillary and 72 cases of multibacillary leprosy were analysed. The macrophages accounting at the most for 3.5% of marrow cells were observed in 5 cases of paucibacillary and 43 cases of multibacillary leprosy with a maximum incidence being observed in patients with ENL (16/17). The lipid present in the cytoplasm of these cells could be derived from the lipid of the cell wall of Mycobacterium leprae. To the best of our knowledge, these cells have not been reported in leprosy so far.

Bone Marrow↗

PubMed1991

Prevalence & spectrum of congenital malformations in a prospective study at a teaching hospital.

A prospective survey for congenital malformations at birth, at a teaching hospital, over a period of two and half years on 9405 consecutive single births has shown that prevalence of major congenital malformations in live births was 1.6 per cent and in still births 16.4 per cent. There was no significant difference in the prevalence of congenital malformations between Hindus (2.0%) and Muslims (2.7%) but amongst Muslims with consanguinity the prevalence of congenital malformation was 4.6 per cent compared to 2.3 per cent in non-consanguineous Muslim spouses (P less than 0.05). Open neural tube defect was the single most common anomaly (31.7% of all malformations) occurring at a rate of 4.7 per 1000 single births, with equal prevalence of anencephaly and meningomyelocoele. Case control study showed that history of concomitant medical illness, drug intake during the first trimester, threatened abortion, hydramnios and pre-eclamptic toxaemia in the current pregnancy were significantly associated with the occurrence of congenital malformations.

Congenital Abnormalities↗

PubMed1991

Isoproterenol fails to produce myocardial necrosis in streptozotocin-induced diabetic rats.

Biochemical alterations in the hearts of non-diabetic and 5 weeks of streptozotocin-induced diabetic rats following isoproterenol (ISO) administration were compared. Serum lactate dehydrogenase (LDH) and myocardial adenosine triphosphate (ATP), creatine phosphate (CP), lactate and glycogen were used as indices of myocardial injury. Hearts from diabetic rats (blood glucose greater than 350 mg/dl), before ISO administration, had normal lactate levels but significantly low high-energy phosphate (HEP) levels and high glycogen levels in comparison to non-diabetic rats. No difference was observed in serum LDH levels between these two groups. ISO administration to non-diabetic rats caused myocardial necrosis as evidenced by a significant depletion of myocardial glycogen and HEPs along with significant myocardial lactate accumulation and an increase in serum LDH. However, the hearts from diabetic rats failed to show any significant HEP depletion, accumulation of lactate and leakage of LDH into serum following ISO-administration, though myocardial glycogen level was significantly lowered. These observations, in conjunction with earlier reports, point to the hypothesis that, in diabetes, there are certain alterations in the sarcolemma which hamper the process by which ISO causes myocardial necrosis.

Animals↗

PubMed1991

Expression of IgG Fc receptor antigens in placenta and on endothelial cells in humans. An immunohistochemical study.

Expression of leukocyte IgG Fc receptor (Fc gamma R) antigens by placenta, endothelial cells (EC) of normal tissues, and ECs of kidney and skin from subjects with immune complex diseases was studied immunohistochemically using anti-Fc gamma R monoclonal antibodies (MAb). Monoclonal antibodies against all three leukocyte Fc gamma R classes stained placental villous macrophages. Placental villous trophoblasts were stained intensely by anti-Fc gamma RIII MAb 3G8, while both anti-Fc gamma RI (MAb 32) and anti-Fc gamma RII MAbs IV3, KU79, CIKM5, 2E1, KB61, and 41H16) antibodies did not react with these cells. Anti-Fc gamma RII MAbs IV3, KU79, CIKM5, 2E1, KB61, and 41H16 immunostained placental villous capillary EC, in contrast to anti-Fc gamma RI MAb 32 and anti-Fc gamma RIII MAb 3G8, CLB-Granl, and B73.1, which did not bind. Anti-Fc gamma RI MAb 32, anti-Fc gamma RII MAb IV3 and CIKM5, and anti-Fc gamma RIII MAb 3G8 did not react with the ECs of tonsil, liver, kidney, spleen, intestine, lung, or uterus. Similarly no EC staining was seen with these four MAbs in 14 skin and 14 kidney biopsies from subjects with immune-complex diseases. Fc gamma R antigens are expressed constitutively only by placental villous ECs and are not induced on nonplacental ECs by immune-complex-mediated diseases.

Antibodies, Monoclonal↗

PubMed1991

Hypermagnesemia following aluminum phosphide poisoning.

Aluminum phosphide (ALP) is highly toxic to the lungs, heart and blood vessels causing pulmonary edema, shock and arrhythmias. There is massive focal myocardial damage resulting in raised cardiac enzymes. This study included 92 patients of proven ALP poisoning. The age varied between 20-50 years and the majority (74) were females. Clinical manifestations were nausea and vomiting (92), dyspnea and palpitation (72 each), cyanosis (54), hypotension (32) and shock (46) etc. Cardiac arrhythmias were present in 80 cases and hypermagnesemia in 78 patients. Mean serum magnesium level (1.95 +/- 0.18 mE/l) was significantly (p less than 0.01) raised compared to mean magnesium level in control subjects (1.62 +/- 0.26 mEq/l). Hypermagnesemia results from myocardial and liver damage and to our knowledge has not been described in the literature. Of 92 cases studied, 66 died, 60 of whom died within 24 hours of ALP ingestion. Treatment is supportive.

Adolescent↗

PubMed1990

Clara cell 10 kDa protein (CC10): comparison of structure and function to uteroglobin.

The cellular localization, functional activities and structures of rat and human Clara cell 10 kDa proteins (CC10) are compared to rabbit uteroglobin. CC10 is present exclusively in the non-ciliated cells of the surface epithelium of the pulmonary airways, whereas uteroglobin is reported to be present in the lung and reproductive organs. There is about 55% identity between the amino acid sequences of rat CC10 and either rabbit uteroglobin or human CC10. The latter two have 61% identity. Using the known structure of uteroglobin as the model, correlations between the structure and function for this group of proteins are made. Substitution of the residues for the rat and human CC10 into the structure of uteroglobin suggests that these proteins may be members of a structurally homologous family. Some of the functional differences may be due to distortion of the hydrophobic pocket in the dimeric protein and a surface hypervariability located on one contiguous helix and beta turn. Rat CC10 and rabbit uteroglobin both, nearly equally, inhibit papain and bind progesterone. Human CC10 does not inhibit papain and has markedly lower progesterone binding (4.6% of rabbit uteroglobin). Antiinflammatory activity of synthetic peptides corresponding to a homologous sequence region of uteroglobin and the two Clara cell proteins was tested. The region chosen has sequence similarity to lipocortin I. The peptides not only failed to inhibit carrageenan-induced foot pad swelling but exacerbated it. All three proteins inhibit pancreatic phospholipase A2. The phospholipase A2 inhibitory effect of CC10 may be important in regulating the inflammatory responses in the lung.

Amino Acid Sequence↗

PubMed1990

Cloning of Bacteroides gingivalis surface antigens involved in adherence.

Despite the acknowledge importance of Bacteroides gingivalis as a periodontal pathogen, relatively little is known about the molecular basis for its pathogenicity. Recombinant DNA technology has created the opportunity to identify and characterize the virulence determinants. A Bact. gingivalis library was prepared in Escherichia coli JM83 with the vector pUC18. The library was screened for surface antigens by colony immunoblot and 337 putative surface antigen recombinants were identified. Two of these clones were found to have haemagglutinating activity. Antiserum raised against one of these clones reacted with a 43 kDa Bact. gingivalis protein that has haemagglutinating activity.

Antigens, Bacterial↗

PubMed1990

Choline deficiency activates phospholipases A2 and C in rat liver without affecting the activity of protein kinase C.

There is evidence to suggest that liver tumor promoters exert their effect through the interference of signal transduction in hepatic cells. Both phospholipase A(2) and phospholipase C play important roles in the generation of second messengers and in the activation of Ca(2+), phospholipid-dependent protein kinase C. Using male Sprague-Dawley rats, we investigated whether liver tumor-promoting regimens of a choline-deficient diet and phenobarbital alter the activities of phospholipase A(2) and phospholipase C in the liver, and extended the study to determine the effect of a choline-deficient diet on protein kinase C activities. Feeding a choline-deficient diet for 1 week increased the activities of both phospholipase A(2) (50%) and phospholipase C (22%), and the activities of both enzymes were more than doubled after 4 weeks. Feeding a phenobarbital diet resulted in a slight decrease in phospholipase A(2) activities at 4 weeks but no significant changes in PLC activities. The protein kinase C activities and its distribution between soluble and particulate fractions remained unchanged after 1, 2, and 4 weeks feeding of a choline-deficient diet. Thus, activation of both phospholipase A(2) and C is distinct for a choline-deficient diet, not shared by phenobarbital diet. Increased activities of these enzymes were not associated with the activation of protein kinase C under the present experimental condition.

Journal Article↗

PubMed1990

Effects of a choline-deficient diet and a hypolipidemic agent on single glutathione S-transferase placental form-positive hepatocytes in rat liver.

Using the placental form of glutathione S-transferase (GST-P) as a marker of carcinogen-initiated hepatocytes, we investigated how a choline-deficient (CD) diet and BR931, a carcinogenic hypolipidemic agent, modify populations of single GST-P-positive hepatocytes. The liver of male Fischer rats (6-7 weeks old) fed a CS or basal diet contained mostly single or double GST-P-positive hepatocytes. Feeding a CD diet for 2-4 weeks led to increases in the number of aggregates of two and three GST-P-positive hepatocytes. By 8-12 weeks, there was an emergence of discrete foci of GST-P-positive hepatocytes consisting of more than 20 hepatocytes. Feeding a BR931 diet for 4-8 weeks resulted in no significant change in the number of single GST-P-positive hepatocytes in the liver as compared to feeding a basal diet. It is suggested that single GST-P-positive hepatocytes in the liver of relatively young rats maintained on a commercial diet may represent endogenously initiated cells. A CD diet promotes endogenously initiated cells to form larger aggregates or foci of GST-P-positive cells.

Animals↗