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Biomedical subjects

M Jacob

Publications and source records attributed to M Jacob.

At least 55 records · Page 3Linked to original sources
PubMed1993

Intrafamilial transmission of leprosy in Vellore Town, India.

A hospital-based study was done from 1968 to 1991 to determine the risk and extent of intrafamilial transmission of leprosy in relation to the characteristics of the index cases and contacts in urban areas in India. Families were examined by doctors annually. Skin smears were done for contacts of multibacillary (MB) leprosy patients. Person years of follow up were computed for each contact and used as the denominator for computation of incidence rates. Specific rates were computed by age, sex, type of leprosy, smear in index cases, age at registration, and sex of contacts. Of the 120 index cases (81 males, 39 females) 44% were MB; 410 contacts (186 males, 224 females) and 14 co-prevalent cases were registered. The cumulative years of follow up was 2725 years. Fourteen contacts developed the disease (9 TT, 3 indeterminate, and 2 BT); 85.7% were in the 0-14 age group; 12 of 14 patients were detected to have leprosy during the first 5 years. The incidence rate (IR) was 5.1/1000 (males 5.15, females 5.12). The IR was 7.3/1000 and 2.3/1000 among contacts of MB and paucibacillary leprosy patients (p < 0.05). The IR in multiple-case families was 1.8. The importance of active surveillance by a hospital-based survey is emphasized. It should be designed to focus on children younger than 15 years and should be limited to 5 years of follow up.

Adolescent↗
PubMed1993

The avian prechordal head region: a morphological study.

The axial mesoderm of the anterior head region was investigated in young chick and quail embryos by light and electron microscopy. Semithin sections showed that the axial head mesoderm consists of the head process and prechordal mesoderm. At the anterior end of the prechordal mesoderm, a group of columnar epithelial cells formed a pit-like structure. The bases of these columnar cells extended to the neural plate, thus limiting the prechordal mesoderm anteriorly. The cells lining the pit-like structure at its anterior end joined a cell accumulation made up of cells of mesenchymal character. Electron microscopy revealed that the columnar cells forming the pit-like structure were covered by a basal lamina which was discontinuous on its anterior aspect. No basal lamina was recognisable between the columnar epithelial cells and mesenchymal cells joining them anteriorly. The columnar epithelial cells bordering the prechordal mesoderm anteriorly were therefore assumed to be part of the endodermal germ layer. In agreement with the findings of other authors, it is proposed to term these axially located columnar cells of the endoderm the prechordal plate and to distinguish them from the prechordal mesoderm arising during gastrulation. For the mesenchymal cell accumulation anterior to the prechordal plate, participation in the formation of the prosencephalic mesenchyme is assumed. This implies that the definitive endodermal germ layer, like the ectodermal one represented by the neural crest, may also be able to contribute to mesenchyme formation in the head.

Animals↗
PubMed1993

Selection between a natural and a cryptic 5' splice site: a kinetic study of the effect of upstream exon sequences.

To study the mechanism of selection of 5' splice sites, we first analyzed the in vitro time course of appearance of intermediates and products of splicing at a natural and at a cryptic 5' splice site. Our model system was a transcript derived from the early transcription unit 3 of adenovirus-2 harboring a cryptic 5' splice site Dcr1, 74 nucleotides downstream of the natural site D1. When studied in isolation, the two sites have different kinetics of splicing, Dcr1 being spliced markedly more slowly than D1. The upstream exon, shown elsewhere to have a positive effect on the selection of D1, has no influence on these kinetics; thus, it does not affect selection by modifying the kinetics of splicing. Nevertheless, this exon is of crucial importance for the exclusive selection of D1. We demonstrate that the cryptic site is recognized in all cases, but that exons harboring a potential stem-loop structure (HP1) prevent Dcr1 usage. The data suggest that the upstream exon sequences play the role of a cis-acting selector for the natural 5' splice site. The intrinsically rapid and efficient kinetics of splicing at the natural site and the selector function of the exon sequence may result in the exclusive use of the D1 site in the natural context.

Adenoviridae↗
PubMed1992

Food safety: action to protect the consumer.

Food safety issues have been headline news frequently in recent years. A review of food legislation was started in 1984 and led to the Food Safety Act 1990. This Act, which may prove to be the last major piece of independent British food law, provides food authorities with new powers to prevent the distribution of contaminated food and ensure that proper practices are being carried out by food businesses, and establishes a registration system for food businesses. Other developments include a new system for the inspection of food premises and plans to introduce a requirement for hygiene training for food handlers. The process of European harmonisation will require a further series of changes--forthcoming proposals provide for quality standards for laboratories, and more frequent inspection requirements covering a wide range of products.

Consumer Product Safety↗
PubMed1992

An outbreak of Salmonella dublin infection in England and Wales associated with a soft unpasteurized cows' milk cheese.

An outbreak of Salmonella dublin infection occurred in England and Wales in October to December 1989. Forty-two people were affected, mainly adults, and most lived in south-east England. Microbiological and epidemiological investigations implicated an imported Irish soft unpasteurized cows' milk cheese as the vehicle of infection. A case-control study showed a statistically significant association between infection and consumption of the suspect cheese (p = 0.001). Salmonella dublin was subsequently isolated from cheeses obtained from the manufacturer's premises. Initial control measures included the withdrawal of the cheese from retail sale and a Food Hazard Warning to Environmental Health Departments, as well as a press release, from the Department of Health. Subsequently, a decision was taken by the manufacturer to pasteurize milk used in the production of cheese for the UK market and importation of the cheese resumed in June 1990.

Adolescent↗
PubMed1992

Clinical and laboratory profile of AIDS in India.

The clinical features and results of laboratory investigations of the first 19 Indian patients with AIDS seen in our hospital are presented. Weight loss, fever, and diarrhea were the most common symptoms. Tuberculosis (TB) was the most common secondary infectious disease; among 13 patients, seven had only pulmonary TB, five had pulmonary and extrapulmonary TB, and one had only extrapulmonary TB. Oropharyngeal candidiasis was found in 11 patients. Other secondary infections were predominantly by virulent bacteria. Opportunistic infections other than candidiasis were infrequent; one patient had cryptococcosis, two had symptomatic cryptosporidiosis, one had noncoagulase-positive staphylococcus septicemia, and one had cytomegalovirus retinitis. Reduced lymphocyte counts (particularly of the CD4 subset), anemia, hypoalbuminemia, hyperglobulinemia, and elevated liver enzyme levels were frequent laboratory findings. Six patients are under follow-up, two are lost to follow-up, and 11 have died. Lymphocyte counts less than 500/mm3 were only seen in those patients who subsequently died. Response to antituberculosis therapy was good in several patients. Thus, the clinical profile of Indian patients with AIDS is not different from the common picture of patients of low socioeconomic and poor hygienic standards; patients presented with TB, undernutrition, and multiple infections. Therefore, a large population of patients with AIDS in India will not be recognized unless they are tested for evidence of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Morphometry of mitochondria in the choroidal ependyma of hydrocephalic guineapigs.

Fifteen young guineapigs were made hydrocephalic by intracisternal injection of kaolin and 16 guineapigs were used as control. Volume, number and surface areas of both the outer and inner membranes of the mitochondria of the choroidal ependyma of these animals were studied, using a coherent multipurpose test system. Volume, number and surface area of the outer membrane of the mitochondria did not show any significant difference between the two groups. However, surface area of the inner membrane of the mitochondria including cristae showed a significant decrease in the hydrocephalic animals. This reduction in the surface area could probably be attributed to the reduced activity of the choroidal ependymal cells in obstructive hydrocephalus.

Animals↗
PubMed1991

The role of fibronectin and laminin in development and migration of the avian Wolffian duct with reference to somitogenesis.

It has been suggested that matrix molecules like fibronectin and laminin influence the differentiation and migration of embryonic cells. We investigated the role of these two glycoproteins in somitogenesis as well as in the differentiation and migration of the avian Wolffian (pronephric and mesonephric) duct. At first, we described essential steps in the development of these two organ anlagen by light microscopy, SEM and TEM. To localize fibronectin and laminin more exactly in the actual stages, we used the indirect immunoperoxidase reaction at the light microscopic level and the peroxidase-antiperoxidase technique at the ultrastructural level. Fibronectin was found at the surface of the unsegmented paraxial mesoderm, increasing in the cranial direction, and in the basal laminae of somites and Wolffian duct. The mesenchymal tip of the duct contains a moderate amount of fibronectin. In the two investigated organ anlagen, laminin was found mainly in the basal laminae. The role of fibronectin and laminin was investigated further by using synthetic peptides that mimic the main cell binding domain of either fibronectin or laminin, and that competitively inhibit their cell surface receptors. Thus, the pentapeptides GRGDS, YIGSR, and for control, SHLVE were micro-injected under the ectoderm of 2-day-old embryos. After treatment with GRDS, the Wolffian duct and the segmental plate are more compact. The rounded cells exhibit only short processes and narrow intercellular spaces. At the side of injection the duct shows a delay in migration. After treatment with YIGSR the Wolffian duct migrated laterally over the somatopleure. The basal laminae seem to be incomplete. SHLVE had no effect. Our results suggest that fibronectin is a prerequisite for the migration of the Wolffian duct, and that laminin probably plays a role in guiding the duct. The epithelialization during somitogenesis and differentiation of the duct is a more complex process involving also fibronectin and laminin.

Animals↗
PubMed1991

A large outbreak of food poisoning of unknown aetiology associated with Stilton cheese.

Between November 1988 and January 1989, a total of 155 people in 36 reported outbreaks suffered gastrointestinal symptoms associated with eating Stilton cheese, produced from unpasteurized cow's milk in the English midlands. Symptoms were suggestive of a staphylococcal illness but extensive laboratory testing of cheeses implicated in several of the outbreaks failed to detect any pathogen, toxin or chemical. Control measures were implemented, and included a voluntary withdrawal of the implicated Stilton cheese from sale on 23 January 1989 and a subsequent decision to use pasteurized milk in production of the cheese.

Abdominal Pain↗
PubMed1991

Identification of a specific exon sequence that is a major determinant in the selection between a natural and a cryptic 5' splice site.

The first intron of the early region 3 from adenovirus type 2 contains a cryptic 5' splice site, Dcr1, 74 nucleotides downstream from the natural site D1. The cryptic site can be activated when the natural site is inactivated by mutagenesis. To investigate the basis for selection between a natural and a cryptic 5' splice site, we searched for cis-acting elements responsible for the exclusive selection of the natural site. We show that both the relative intrinsic strength of the sites and the sequence context affect the selection. A 120-nucleotide segment located at the 3' end of exon 1 enhances splicing at the proximal site D1; in its absence the two sites are used according to their strength. Thus, three cis-acting elements are involved in the silencing of the cryptic site: the sequence of D1, the sequence of Dcr1, and an upstream exonic sequence. We show that the exonic element folds, in solution, into a 113-nucleotide-long stem-loop structure. We propose that this potential stem-loop structure which is located 6 nucleotides upstream of the exon 1-intron junction is responsible for the preferential use of the natural 5' splice site.

Adenoviridae↗
PubMed1991

[Parameters for the formulation of physical-technical characteristics of granules of theophylline obtained by extrusion-spheronization].

Spheroids are prepared from microcrystalline cellulose in binary and compound combination with lactose and theophylline, in certain fixed conditions of extrusion and of spheronisation. The present work envisages the influence of combinated raw materials upon the physical-technique characteristic of the made spheroids. Besides a variation in the granulometric distribution a statical study through analysis of variance brings to the fore that the parameters of formulation contribute to modify the properties of hardness and of friability of the minigranules.

Drug Compounding↗
PubMed1991

[Results of Billroth I and Billroth II stomach resection].

Between 1966 and 1986, Billroth I and Billroth II resections for gastroduodenal ulcers were performed at the Department of Surgery, Friedrich Schiller University, Jena. Early postoperative complications after Billroth II (14.6%) were somewhat rarer than after Billroth I (19.4%), however, bore a greater risk. With a permanent cure accounting for 85%, the comparison of both procedures reveals no significant differences in the late results. In gastric ulcer, Billroth's first method should be given preference because it can be carried out more rapidly in technical respect and takes digestive physiology into account.

Female↗
PubMed1991

Fixed duration MDT in paucibacillary leprosy.

The World Health Organization (WHO) has recommended a fixed duration of multidrug therapy (MDT) for paucibacillary leprosy which is currently widely implemented in India. A clinico-pathological study was initiated in 1984 to assess the efficacy of this regimen. The clinical and histological responses of the patients to MDT were assessed at the end of 6 months, when their treatment was stopped, and at 2 1/2 years, when they were released from surveillance, and compared with the responses of a matched patient group to conventional dapsone (DDS) monotherapy during the same period. Of 28 patients who completed the MDT schedule, there was less than 60% improvement in 33% of them when treatment was stopped at the end of 6 months and in 20% of them at the end of 2 1/2 years. Of 26 patients receiving DDS monotherapy, 37% showed less than 60% improvement at the end of 6 months but only 8.8% had less than 60% improvement at 2 1/2 years. It is concluded that MDT for paucibacillary leprosy as recommended by WHO may not have a major advantage over DDS monotherapy, since about 20% of those patients on MDT continue to have evidence of active disease when discharged from surveillance.

Adolescent↗
PubMed1990

Isolation and typing of herpes simplex viruses in the infections of mouth, respiratory and genital tracts.

A total of 60 herpes simplex virus (HSV) isolates obtained from individuals with genital herpes lesions in the mouth or respiratory illness were typed in this study. The HSV isolation rate in genital herpes was 31%. The typing was done by a direct fluorescent monoclonal antibody technique using commercial reagents. All the 60 Vero cell grown isolates were successfully typed without any indeterminate results. Nine isolates were typed as HSV 1 and 51 as HSV 2. The technique was easy to perform and read. HSV 2 was found to predominate in genital infections and HSV 1 in respiratory infections.

Fluorescent Antibody Technique↗