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Biomedical subjects

R Joseph

Publications and source records attributed to R Joseph.

At least 37 records · Page 2Linked to original sources
PubMed2000

Assessment of in vivo chromosomal aberrations--potency of zinc mercapto benzo thiazole.

Chromosomal aberrations are microscopically visible changes in the chromosome structure. The double-stranded breaks are the ultimate DNA lesions for chromosomal aberrations. The purpose of the present study was to evaluate the induction of chromosomal aberrations by the rubber accelerator zinc mercapto benzo thiazole (ZMBT). The experiment was designed with five groups, each composed of four Swiss albino mice. The first three groups received ZMBT at 1920, 960, and 480 microg/20 g animal. The remaining two groups were the vehicle (cotton seed oil) and positive (methyl methane sulphonate) controls. Animals were given a single dose of test and control samples by IP injection. Colchicine (20 microg/animal) was administered 90 minutes before sacrificing the animals. All the animals were sacrificed at the end of 36 h by cervical dislocation. Bone marrow preparations were made, stained with Giemsa stain, and examined for chromosomal abnormalities. The results indicated a lack of incidence of chromosomal abnormalities in the test and control groups. However, significant chromosomal abnormalities such as gaps, breaks, and translocations were observed in the positive control group. Hence, the study concluded that ZMBT at different concentrations fails to induce structural chromosomal aberrations in bone marrow cells.

Animals↗
PubMed2000

A case report on the perinatal management of a 30-week preterm baby with congenital complete heart block.

INTRODUCTION: Congenital complete heart block is an uncommon condition in the newborn, but is known to occur with maternal systemic lupus erythematosus. CLINICAL PICTURE: This paper presents one such baby with complete heart block who was born premature (after a gestation of 30 weeks) and weighing 759 g. TREATMENT: Continuous isoprnaline infusion was initially used to support the baby while her other neonatal problems were treated. A Medtronics VV1 pacemaker was subsequently inserted to maintain a heart rate that would be more physiologically acceptable for the patient. OUTCOME: This baby is currently thriving well, having been followed up for one year. CONCLUSIONS: The management issues, encompassing maternal and neonatal problems, and a review of current literature on this condition are discussed.

Adult↗
PubMed1999

Strain improvement of Aspergillus sp. and Penicillium sp. by induced mutation for biotransformation of alpha-pinene to verbenol.

Variants of Aspergillus sp. and Penicillium sp. obtained after treatment with colchicine, ethyl methanesulphonate (EMS), or ultraviolet (UV) irradiation indicated varying levels of significant increases in their efficiency to transform alpha-pinene to verbenol. In case of Aspergillus sp. the UV-induced variant was the best performer with a 15-fold increase in biotransformation efficiency compared to the wild type. In case of colchicine and EMS-induced variants the biotransformation increases were 2- and 8-fold, respectively. The UV-induced variant of Penicillium sp. was capable of eight fold increase in efficiency while the colchicine- and EMS-induced variants were 1.5- and 2-fold, respectively. The variants were characterised with respect to changes in colony morphology, spore dimension, DNA content, and products formed, viz. verbenol and verbenone.

Aspergillus↗
PubMed1999

Tensile set behavior of Foley catheter balloons.

The removal of indwelling urinary balloon catheters from patients is usually associated with many problems. The problems such as balloon deflation failure; encrustations on balloons, eyes, and lumen; and catheter associated infections are widely discussed in the literature. The tensile set exhibited by the catheter balloon material could also play a role and further complicate the removal process. This article addresses this issue by comparing the tensile set behavior of the balloon material from three commercially available Foley catheters. The balloon materials were subjected to aging in synthetic urine at 37 degrees C for 28 days to simulate clinical conditions. The deflation time of catheter balloons aged in similar conditions were also measured. It was found that different brands of catheters exhibited statistically significant differences in their properties. The tensile set data of the aged samples could be correlated with the deflation time of the balloons. The clinical significance of the tensile set is also highlighted.

Biocompatible Materials↗
PubMed1999

Surveillance behavior of women with a reported family history of colorectal cancer.

STUDY OBJECTIVE: The present study tested whether the surveillance behavior of women with a family history of colorectal cancer (CRC) differed from that of women without such a history. DESIGN: The study included 72,710 subjects from the population of E3N, a cohort study, part of the European Prospective Investigation on Cancer, investigating risk factors for cancer among women. RESULTS: Fecal occult-blood testing (FOBT) was reported by 19.4% of the women with no CRC in their family and by 21.8% of those with one or more CRC (frequency odds ratio (FOR) = 1.01; ns). The degree of kinship did not influence FOBT. Colonoscopy was reported by 10.9% of women with no CRC in their family; its frequency increased with increasing number of subjects affected by CRC in the family, in particular when it concerned first-degree relatives. Colonoscopy was reported almost four times more frequently by subjects having two or more first-degree relatives with CRC (FOR = 3.55; 95% CI 2.47-5.10) than by those without any affected member; the frequency of colonoscopy increased, though less sharply, among women with second-degree affected relatives, compared with those without any affected relative in their family. CONCLUSION: In conclusion, whereas FOBT was unaffected by family history of CRC, screening colonoscopy was more frequent among women with a reported family history and differed with the degree of kinship of the affected relatives. The high rate of colonoscopy observed among subjects with first- and second-degree relatives is likely due to physician participation in screening decisions.

Adult↗
PubMed1999

The neurology of traumatic "dissociative" amnesia: commentary and literature review.

BACKGROUND: The relationship between traumatic emotional stress, hippocampal injury, memory loss, and traumatic ("dissociative") amnesia was examined. METHOD: A survey of the research on emotional trauma, learning, memory loss, glucocosteroid stress hormones, and the hippocampus was conducted, and animal and human studies were reviewed. RESULTS: It is well documented and has been experimentally demonstrated in animals and humans that prolonged and high levels of stress, fear, and arousal commonly induce learning deficits and memory loss ranging from the minimal to the profound. As stress and arousal levels dramatically increase, learning and memory deteriorate in accordance with the classic inverse U-shaped curve. These memory deficits are due to disturbances in hippocampal activation and arousal, and the corticosteroid secretion which can suppress neural activity associated with learning and memory and induce hippocampal atrophy. Risk and predisposing factors include a history of previous emotional trauma or neurological injury involving the temporal lobe and hippocampus, the repetitive and prolonged nature of the trauma, and age and individual differences in baseline arousal and level of cortisol. CONCLUSIONS: Although some victims may be unable to forget, amnesia or partial memory loss is not uncommon following severe stress and emotional trauma. Even well publicized national traumas may induce significant forgetting. Memory loss is a consequence of glucocosteroids and stress-induced disturbances involving the hippocampus, a structure which normally plays an important role in the storage of various events in long-term memory.

Amnesia↗
PubMed1999

Environmental influences on neural plasticity, the limbic system, emotional development and attachment: a review.

The effects of early environmental influences on neural plasticity, the limbic system, and social and emotional development are reviewed and an illustrative case study is briefly discussed. Deprived or abnormal rearing conditions induce severe disturbance in all aspects of social and emotional functioning, and effect the growth and survival of dendrites, axons, synapses, interneurons, neurons, and glia. The amygdala, cingulate, and septal nuclei develop at different rates which correlate with the emergence of wariness, fear, selective attachments, play behavior, and the oral and phallic stages of development. These immature limbic nuclei are "experience-expectant," and may be differentially injured depending on the age at which they suffer deprivation. The medial amygdala and later the cingulate and septal nuclei are the most vulnerable during the first three years of life. If denied sufficient stimulation these nuclei may atrophy, develop seizure-like activity or maintain or form abnormal synaptic interconnections, resulting in social withdrawal, pathological shyness, explosive and inappropriate emotionality, and an inability to form normal emotional attachments.

Affective Symptoms↗
PubMed1999

Frontal lobe psychopathology: mania, depression, confabulation, catatonia, perseveration, obsessive compulsions, and schizophrenia.

The frontal lobes can be subdivided into major functional neuroanatomical domains, which, when injured, surgically destroyed, or reduced in activity or volume, give rise to signature pathological and psychiatric symptomology. A review of case reports and over 50 years of research, including magnetic resonance imaging, positron emission tomography, and single photon emission computed tomography scans, indicates that apathy, "blunted" schizophrenia, major depression, and aphasic-perseverative disturbance of speech and thought are associated with left lateral as well as bilateral frontal (and striatal) abnormalities. Impulsiveness, confabulatory verbosity, grandiosity, increased sexuality, and mania are associated with right frontal (as well as bilateral) disturbances. Gegenhalten, catatonia, and disturbances of "will" are indicative of medial frontal injuries. Disinhibitory states and obsessive-compulsive perseverative abnormalities are more frequently observed with orbital frontal lobe dysfunction, including frontal-striatal disturbances. These associations, however, are not always clear-cut as patients with the same diagnosis may demonstrate different symptoms that may be due to an additional abnormality in a different region of the brain. Moreover, as the frontal subdivisions are richly interconnected, and as frontal lobe abnormalities are not always discrete or well localized, a wide array of seemingly divergent waxing and waning symptoms may be manifest, sometimes simultaneously, including manic depression and what has been referred to as the "frontal lobe personality."

Bipolar Disorder↗
PubMed1999

A large prospective survey of anti-cardiolipin antibodies in chronic hemodialysis patients.

We prospectively measured anti-cardiolipin antibody (ACLA) levels in 230 chronic hemodialysis (HD) patients over a 2-year period. Twenty-nine percent of HD-patients were found to have elevated IgG-ACLA titers. Males were more likely to have elevated IgG-ACLA titers. Elevated IgG-ACLA titers correlated with shortened AVG survival in HD-patients (mean of 156 vs. 238 days, p<0.05). There was no statistically significant correlation with access survival in AVF-patients. There seemed to be a higher mean IgG-ACLA titer in diabetics but they did not have statistically significant shorter angioaccess survival times. By logistic regression analysis, only IgG-ACLA positivity was predictive of premature angioaccess failure (p<0.05). In a selected subset of 16 patients with frequent angioaccess (AVG) failure and elevated IgG-ACLA levels, coumadin, titrated to an INR of 2 - 3, was found to produce a small (though statistically significant) prolongation of AVG survival.

Adolescent↗
PubMed1999

Newborn screening in Singapore.

Neonatal screening in Singapore for G6PD deficiency started in 1965. Screening for congenital hypothyroidism started in 1981 as a pilot research program and by 1990, it became nationwide. Screening for congenital hypothyroidism is by the measurement of TSH in the cord serum with recall of those exceeding the 99th percentile, by about 3-4 days of life. Treatment is usually started within a week of life. Over 400,000 newborns have been screened and the screening rate has been about 99.95%. The incidence rate is about 1 in 3,000. G6PD activity in the cord blood is measured using semi-quantitative rapid screening tests. Those identified are physically protected from environmental triggers by keeping them in hospital for a variable period of time. Parents are counseled. Data obtained from 22,830 newborns from the National University Hospital revealed incidence rates of 1.62% in all newborns, 3.15% in males and 0.11% in females. The Chinese and Malay males had a higher (3.94% and 2.95%) incidence respectively when compared to the Indian males with (0.66% incidence). The application of the preventive measures has resulted in no report of kernicterus in the last 20 years. Our efforts are now focused on minimizing the recall rate in the case of hypothyroidism screening, reducing the period of stay in hospital in those with G6PD deficiency and considering the introduction of a PKU screening program in Singapore.

Congenital Hypothyroidism↗
PubMed1999

Mass newborn screening for glucose-6-phosphate dehydrogenase deficiency in Singapore.

Recognition of kernicterus as a significant contributor to newborn mortality and morbidity in G6PD deficient babies and the ease with which G6PD deficiency could be detected and kernicterus prevented by avoidance of triggers, led to the establishment of mass newborn screening for G6PD deficiency in 1965. G6PD deficient newborns are identified within a day of birth by measuring the enzyme activity in cord blood. They are then physically protected from triggers by keeping them in the hospital for the first 2 weeks of life after their parents are counseled. Enzyme activity is measured using Wong's in-house modification of the Bernstein's technique or the BM G6PD Deficiency Screening test based on the Beutler assay. Close to 1.6 million newborns, representing practically 100% of all births have been screened. Analysis of data from 22,830 newborns at the National University Hospital reveals an incidence of 1.62% in all newborns. 3.15% in males and and 0.11% in females. A distinct racial variation in the incidence of deficiency was observed in males: Chinese 3.94%, Malays 2.95% and Indians 0.66%. Intermediate deficiency was most frequently identified (1.83%) in Chinese females. With the preventive measures. the incidence of kernicterus has dropped dramatically and there has been, over the last 20 years, no reported cases of kernicterus in newborns with G6PD deficiency. We are now looking at issues like comparing different assay techniques and determining a shorter period of stay in hospital. We believe that all Asians, especially Chinese babies, should be screened for G6PD deficiency, irrespective of which country the child is born.

Female↗
PubMed1998

Hydroxyapatite-polyethylene composites for bone substitution: effects of ceramic particle size and morphology.

Synthetic hydroxyapatite particles of two median sizes and different morphologies have been used to manufacture hydroxyapatite reinforced high density polyethylene composites (HAPEX) for medical applications. The effects of hydroxyapatite particle size on properties of the resultant composites were investigated using various techniques. It was found that composites with smaller hydroxyapatite particles had higher torsional modulus, tensile modulus and tensile strength, but lower strain to failure. Examination of fracture surfaces revealed that only a mechanical bond existed between the filler and the matrix. It was shown that dynamic mechanical analysis is useful in studying the viscoelastic behaviour of the composite.

Bone Substitutes↗
PubMed1998

Genetic variability and diversity for protein and calcium contents in finger millet (Eleusine coracana (L.) Gaertn) in relation to grain color.

Analysis of 36 genotypes of finger millet (Eleusine coracana (L.) Gaertn) with varying seed colors revealed a wide range of protein and calcium contents. White seeded genotypes had higher protein contents, while brown seeded types had a wide range of values. The brown seeded genotype GE 2500 had the highest protein content. Although protein content had significant negative association with calcium content, white seeded types had moderate levels of calcium. The genotypic coefficients of variability were moderate and high for protein and calcium, respectively. High heritability coupled with high genetic advance indicated their governance by additive gene action. A negative significant correlation was observed between protein content and grain yield. Mahalanobis D2 analysis grouped the 36 genotypes into eight clusters. Clustering pattern failed to indicate any relationship between genetic diversity and geographic diversity. Based on genetic diversity and performance, the genotypes MS 1168, MS 174 and CO 13 were found to be suitable for use as parents in a hybridization program for improving yield; the genotypes MS 1168, MS 174 and MS 2869 for protein and Malawi 1915 and CO 11 for calcium. Protein and calcium contents contributed less to genetic divergence.

Calcium↗
PubMed1998

Traumatic amnesia, repression, and hippocampus injury due to emotional stress, corticosteroids and enkephalins.

The role of stress, arousal, emotional trauma, and corticosteroid and enkephalin secretion on memory and the hippocampus, and the development of traumatic amnesia and repressed memory syndrome are detailed. Animal and human studies are reviewed. Trauma-induced memory deficits appear to be secondary to abnormal neocortical and hippocampal arousal, and corticosteroid and enkephalin secretion which can induce atrophy or seizures within the hippocampus, suppress hippocampal theta activity and long term potentiation, as well as injure hippocampal pyramidal cells. Predisposing factors include individual, age, and sex differences in arousal, and previous emotional trauma or temporal lobe or hippocampal injury. However, as the amygdala processes and stores emotional experiences in memory, patients may also demonstrate trauma related symptoms, including flashbacks as well as shrinking retrograde amnesia.

Adrenal Cortex Hormones↗
PubMed1998

Nutritional quality of lactic fermented bitter gourd and fenugreek leaves.

Pediococcus pentosaceus was selected from isolates obtained from the naturally fermenting bitter gourd and fenugreek leaves based on its high titre and broad spectrum of inhibitory activity against spoilage organisms. This strain was then employed for fermentation of bitter gourd and fenugreek which resulted in a more acceptable product having enhanced fat, pyridoxine and ascorbic acid levels. It was of interest to note that vitamin B12 was formed in the fenugreek as a result of the fermentation.

Developing Countries↗
PubMed1998

Reducing cervical cancer among First Nations women.

First Nations women in British Columbia have a four to six times higher mortality rate from cancer of the cervix than do women in the general population. Their participation in the provincial Cervical Cytology Screening Program (CCSP) is less regular and less frequent than other women in B.C. Likewise, they have more difficulty in obtaining culturally suitable health care services from respectful and consistent professionals. These issues should be of critical concern to nurses, as nurses provide the majority of health services to First Nations people.

British Columbia↗
PubMed1998

Anteriomesenteric duodenal compression syndrome.

We report the case of a 48 year old man who presented with a 4 month history of vomiting and weight loss. Barium studies and upper gastrointestinal endoscopy demonstrated anteriomesenteric duodenal occlusion. We discuss the possible aetiology and significance of his investigation findings and subsequent management.

Humans↗