PubMed Health⌕ Search

Biomedical subjects

M R Pinto

Publications and source records attributed to M R Pinto.

At least 37 records · Page 2Linked to original sources
PubMed1993

High-pressure injection injuries of the hand: review of 25 patients managed by open wound technique.

This article reviews the outcome of injury of the hand in 25 patients treated at our institution by the open wound technique: wide débridement, drainage, open packing, and delayed closure. The results obtained are superior to those reported in the literature: Among the patients, 84% of the involved hands or fingers were salvaged, 64% had essentially normal hand function at the time of final follow-up, and 92% were able to return to their previous jobs. We propose that aggressive treatment by the open wound technique improves the outcome of high-pressure injection injuries of the hand.

Accidents, Occupational↗
PubMed1992

Purification and characterization of a vitelline coat lysin from Ciona intestinalis spermatozoa.

In Ciona intestinalis a chymotrypsin-like activity is involved in sperm penetration of the egg vitelline coat. A chymotrypsin-like enzyme has been purified from spermatozoa by a protocol including ion exchange chromatography, gel filtration, and native polyacrylamide gel electrophoresis. The purified enzyme resulted homogeneous when analyzed by SDS-PAGE. The molecular weight of the chymotrypsin-like enzyme was estimated to be 35 kDa by gel filtration and 24 KDa by SDS-PAGE in nonreducing conditions. The pH optimum of the enzyme is 8.4 and its activity is enhanced by Ca2+. It shows the highest activity towards the synthetic substrate Suc-Ala-Ala-Pro-Phe-AMC. Furthermore, by electron microscopy, the purified enzyme affects the structure of egg vitelline coat, and thus it fulfills one of the criteria of a lysin.

Amino Acid Sequence↗
PubMed1992

Evidence that metalloendoproteases are involved in gamete fusion of Ciona intestinalis, ascidia.

The use of specific inhibitors and substrates of metalloendoproteases provides evidence that in many systems these enzymes are involved in membrane fusion events. In this study, we investigated whether metalloendoproteases are involved in Ciona sperm-egg fusion. In vitro fertilization assays with the metal chelator 1,10-phenanthroline, specific metalloendoprotease substrates, and the vital stain Hoechst 33342 suggested that a Zn(2+)-dependent metalloendoprotease(s) takes part in Ciona sperm-egg fusion. Furthermore, electrophysiological recordings showed that insemination carried out in the presence of either 1,10-phenanthroline or the substrate CBZ-Gly-Phe-NH2 fails to induce fertilization potential or any other change in membrane potential. These results support the hypothesis that in Ciona intestinalis, a metalloendoprotease(s) is functional in gamete fusion.

Animals↗
PubMed1992

Two cases of listeriosis.

This is the second report of listeriosis in Sri Lanke. It is a disease with a changing clinical pattern. Most cases are from people at the extremes of age and from people with an underlying malignancy of the lymphoproliferative and renal transplant patients. But it is now being increasingly reported in previously healthy people. The two cases presented here are from previously healthy children. Both of them also manifested a rash which helped in the detection of the second case. A rash has not been described in the literature as characteristic or a common feature other than in neo-natal listeriosis.

Child↗
PubMed1991

Gamete self-discrimination in ascidians: a role for the follicle cells.

Gamete self-incompatibility in the hermaphrodite tunicate Ciona intestinalis is a useful system with which to study self-nonself recognition. We have used in vitro fertilization of oocytes isolated from the gonad of Ciona intestinalis to identify the cellular source of self-sterility elements present on the egg envelopes. Here we show for the first time that self-discrimination, which occurs on the egg vitelline coat, is established there in late oogenesis and is contributed or controlled by products of the overlying follicle cells. The acquisition of self-sterility by the oocyte is prevented by the ionophore monensin, which suggests that the follicle cell self-sterility controlling factor is a glycoprotein.

Animals↗
PubMed1990

Chymotrypsin-like enzymes are involved in sperm penetration through the vitelline coat of Ciona intestinalis egg.

In Ciona intestinalis, sperm penetration through the egg vitelline coat is an essential event of fertilization. We investigated whether trypsin- and chymotrypsin-like enzymes are involved in this event. Inhibitors and peptide substrates for chymotrypsin-like enzymes blocked the overall process of fertilization in a concentration-dependent manner. The inhibitory activity was specifically exerted on the step of sperm penetration. Chymotrypsin-like protease activity was identified in spermatozoa with the fluorogenic synthetic substrate Suc-Ala-Ala-Phe-AMC, which was the most effective substrate in blocking sperm penetration. These data indicate that a chymotrypsin-like protease activity is a sperm lysin of Ciona intestinalis.

Amino Acid Sequence↗
PubMed1990

Microbiological agents associated with childhood diarrhoea in the dry zone of Sri Lanka.

Between March and July, 1987, faecal specimens from 371 diarrhoeal children reporting to four hospitals in the district of Kurunegala, Sri Lanka and from 121 controls with other diseases were investigated for enteric pathogens. All specimens were tested for Shigella spp, Salmonella spp and enteropathogenic Escherichia coli (EPEC). In addition, parasitic pathogens, heat labile enterotoxigenic Escherichia coli (ETEC LT), Campylobacter and rotavirus were sought among subsamples of the cases and controls. One or more pathogens were detected in the faecal specimens of 53.7% of the diarrhoeal children and 19.6% of the controls (P less than 0.001). Rotavirus was the most frequently identified pathogen. Cases (21.9%) were more likely to be positive for rotavirus than controls (6.5%) (p less than 0.05). Among children with diarrhoea the peak prevalence of rotavirus occurred in the 6-11 months age group. Shigella spp were the second most frequently isolated pathogens and the single most common cause of diarrhoea in children over two years of age. Again, cases (16.4%) were more likely to be infected than controls (1.7%) (p less than 0.001). Salmonella spp were isolated from 7.5% of diarrhoeal children and 3.3% of the controls (p greater than 0.10). Other pathogens had prevalence rates of less than 5%. Vomiting was associated with rotavirus diarrhoea (p less than 0.001), and fever with shigellosis (p = 0.02). In view of the different transmission routes and characteristics of the most important pathogens detected in this study it appears unlikely that a single environmental intervention can solve the public health problem posed by diarrhoeal diseases in Sri Lanka.

Acute Disease↗
PubMed1988

Cortical and cancellous bone: age-related changes in morphologic features, fluid spaces, and calcium homeostasis in dogs.

The changes in cortical and cancellous bone that occur with aging were studied by measuring morphologic and physiologic variables for both types of bone in dogs. The percentage area of cortical and cancellous bone, rate of bone formation, vascular volume, bone water, and volume of distribution of calcium tracer all showed statistically significant changes at the time of bone maturity. Canine cortical bone cell volume progressively decreased with advancing age, and cancellous bone cell volume significantly decreased between adult and old dogs. The volume of distribution technique can be used to determine the relative contributions of cortical and cancellous bone to the total body exchangeable calcium ion pool.

Aging↗
PubMed1988

Age-related changes in composition and Ca2+-binding capacity of canine cortical bone extracts.

The variable of age was used to study macromolecules in bone that may mediate in part the in vivo readily exchangeable calcium-binding capacity (VCa2+D). Organic components were extracted from nonmineralized bone with 4 M guanidine-HCl and from both nonmineralized and mineralized bone with 0.1 M EDTA. The composition of pup bone extracts demonstrated an enrichment in protein, hexuronate, sialic acid, organic phosphorus, and bound sulfate when compared with other age groups. In vitro calcium-binding studies identified low-affinity (Kd congruent to 10(-3) M) sites in both types of extracts; high-affinity sites (Kd congruent to 10(-5) M) were only evident in EDTA extracts of bone. Readily exchangeable calcium-binding capacity in vivo was found to decrease from pup (40.7 mM) to adolescent (11.1 mM) to the mature/old groups (2.6/1.2 mM); however, a large difference in low-affinity site number was only observed between pup and adolescent bone extracts. The overall organic composition of EDTA and guanidine-HCl extracts generally reflected the composition of total bone, which dropped dramatically on a dry weight basis from pup to adolescent groups. A similar pattern was observed with the number of low-affinity binding sites measured in vitro. In vitro binding data indicate that nonmineralized matrix of pup bone, extractable by 4 M guanidine-HCl, possesses enough capacity to accommodate approximately 40% of the readily exchangeable pool. As age progresses, other components of the blood-bone exchange process, such as vascularity, may reduce the readily exchangeable calcium pool size below the amount of low-affinity sites measured in vitro.

Aging↗
PubMed1987

Localization of the human c-mos gene by in situ hybridization in two cases of acute nonlymphocytic leukemia type M2.

The t(8;21)(q22.1;q22.3) is specific for the FAB-M2 subtype of acute nonlymphocytic leukemia (ANLL). The human c-mos protooncogene is located near the site of rearrangement on chromosome #8, at a position corresponding to band 8q22. The present in situ hybridization studies were performed in order to establish if c-mos is transposed from chromosome #8 to chromosome #21, in two cases of M2-ANLL showing the typical t(8;21). A statistical analysis of the results revealed that the c-mos oncogene was definitely not translocated from chromosome #8 to #21 in one of these patients, and was inconclusive in the other patient. The findings in the former patient suggest that either c-mos is not involved in the etiology of M2-ANLL or, alternatively, if c-mos is important in the pathogenesis of this disease, it must be activated by some mechanism other than transposition of this oncogene to an aberrant position.

Acute Disease↗
PubMed1987

A unique 8;16 translocation in two infants with poorly differentiated monoblastic leukemia.

Acute monoblastic leukemia is nonrandomly associated with abnormalities involving 11q. Two infants, one a neonate and the other 19 months of age, had the same hitherto undescribed karyotypic abnormality, t(8;16)(p11;p13), associated with acute nonlymphocytic leukemia M5a. The older child had an additional translocation, t(10;11)(q11;p15), but the chromosome arms affected were the opposite to those described in acute nonlymphocytic leukemia M5a of childhood. Therefore, it is postulated that genes involved in monocytic differentiation may be situated on 8p11 or 16p13, as well as on 11q.

Bone Marrow↗
PubMed1987

Effects of age on cell size and ion uptake in canine cortical bone.

In cortical bone from dogs of various ages, the uptakes of two bone-seeking isotopes, 85Sr and 99mTc-methylene diphosphonate (MDP), were compared with that of the intracellular cation 42K by using the volume of distribution (VD) technique. The rate of bone remodeling and the osteocyte volume were estimated by morphometric techniques. The percentage cell volume was related to the VD of 42K (r = 0.83; P less than 0.001) and decreased with increasing age. The decline in the VD of 85Sr and 99mTc-MDP with aging was related to the decrease in bone formation (r = 0.90; P less than 0.001). On a logarithmic plot, the cell volume and the VD of 42K had a linear relationship with the rate of new bone formation, the VD of 85Sr, and the VD of 99mTc-MDP. Our results demonstrate that, with increasing age in dogs, the bone formation rate and cell size decrease, as does the uptake of 42K, 99mTc-MDP, and 85Sr.

Aging↗
PubMed1987

Abnormalities of chromosome 12p13 and malignant proliferation of eosinophils: a nonrandom association.

Four patients representing a spectrum of haematological malignancies are reported. Two patients had Philadelphia chromosome negative myeloproliferative disorders, one had acute lymphoblastic leukaemia and one had eosinophilic leukaemia. In each case eosinophilia was present and demonstrated to be part of the malignancy by the association of clonally abnormal metaphases with eosinophil granules. Abnormalities involving the short arm of chromosome 12 (12p13) were a constant feature in all four cases and therefore a nonrandom association between this chromosome region and malignant eosinophil proliferation is proposed.

Acute Disease↗