Biomedical subjects

A Dubey

Publications and source records attributed to A Dubey.

At least 19 recordsLinked to original sources

PubMed2007

Characterization of ionically bound peroxidases from apple (Mallus pumilus) fruits.

Ionically bound peroxidases (POD) were salt extracted from the pulp of four Indian apple varieties, i.e., Golden delicious HP, Golden delicious JK, Red delicious, and Royal delicious. They were precipitated with chilled ethanol. Thermal treatments of partially purified enzymes were given from 40-70 degrees C for 30 minutes. Golden delicious HP peroxidase showed thermostability at 60 degrees C, while three other peroxidases were observed at 50 degrees C. Phenolic compounds (i.e., caffeic acid, ferulic acids, p-coumaric acid, protocatechuic acid) and metal ions (i.e., Cu2+ and Fe2+) activated all apple peroxidases. However, Mn2+ inhibited the peroxidases from Golden delicious HP, Golden delicious JK, and Red delicious, and a substantial increase was observed in Royal delicious peroxidase. Mg2+ inhibited the peroxidases from Golden delicious HP and Red delicious, but marginal activation was reported in peroxidases from Golden delicious JK and Royal delicious. Zn2+ established stimulation in Golden delicious HP and Golden delicious JK peroxidases, but inhibition was observed in peroxidases in Red delicious and Royal delicious.. Methionine, proline, tryptophan, and valine stimulated all four apple peroxidases, but cysteine showed inhibition in Golden delicious JK.

Amino Acids↗

PubMed2005

Men and women have similar Q angles: a clinical and trigonometric evaluation.

The Q angle is an important determinant of patellar tracking, though its clinical relevance is debatable. One controversy centres around any possible differences in its value between men and women. The accepted, though unproven explanation, for the greater Q angle in women is that a woman has a wider pelvis. However, because of the long distance between the pelvis and patella, relative to the distance from the patella to the tibial tuberosity, large changes in the position of the anterior superior iliac spine are necessary to effect significant changes in the Q angle. In our study of 69 subjects, we did not find such large differences in the position of the anterior superior iliac spine, and found a mean difference of only 2.3 degrees between the Q angles of men and women. Furthermore, we found that men and women of equal height demonstrated similar Q angles, with taller people having slightly smaller Q angles. The slight difference in Q angles between men and women can be explained by the fact that men tend to be taller.

Adolescent↗

PubMed2005

Peeping through heart's window: a case report of Fallots tetralogy.

Tetralogy of Fallot is a congenital heart defect. A combination of four abnormalities in heart allow oxygen rich and oxygen-depleted blood to mix. The resulting low-oxygen blood then circulates through the body. A child with the condition tends to develop slowly, eat poorly and grow slowly and may experience "blue" spells on crying and dyspnea on exertion. A 12 year old child with this congenital heart defect and cleft palate with cleft lip is discussed. Details of the latest diagnostic and treatment procedures are also presented.

Child↗

PubMed2005

Dentofacial changes and oral health status in mentally challenged children.

The study was carried out on 69 mentally challenged individuals. They were subjected to detailed clinical evaluation for dentofacial abnormalities and oral health status. Of the 69 mentally handicapped individuals 27 had Downs syndrome and 42 had cerebral palsy. Characteristic facial abnormalities were seen in children with Downs syndrome. In cerebral palsy, fracture maxillary anteriors were more evident. All the Downs syndrome cases had abnormal TMJ movements but in cerebral palsy only 35.7% of individuals had abnormal TMJ movements. In both the groups, submandibular lymph adenopathy was reported. Present study revealed dental caries in 56.0% of the individuals. Fair clinical level of oral hygiene in 60% of the individuals was seen.

Adolescent↗

PubMed2004

Clustering protein sequence and structure space with infinite Gaussian mixture models.

We describe a novel approach to the problem of automatically clustering protein sequences and discovering protein families, subfamilies etc., based on the theory of infinite Gaussian mixtures models. This method allows the data itself to dictate how many mixture components are required to model it, and provides a measure of the probability that two proteins belong to the same cluster. We illustrate our methods with application to three data sets: globin sequences, globin sequences with known three-dimensional structures and G-protein coupled receptor sequences. The consistency of the clusters indicate that our method is producing biologically meaningful results, which provide a very good indication of the underlying families and subfamilies. With the inclusion of secondary structure and residue solvent accessibility information, we obtain a classification of sequences of known structure which both reflects and extends their SCOP classifications. A supplementray web site containing larger versions of the figures is available at http://public.kgi.edu/approximately wid/PSB04/index.html

Amino Acid Sequence↗

PubMed2004

Molecular machines.

Molecular machines are tiny energy conversion devices on the molecular-size scale. Whether naturally occurring or synthetic, these machines are generally more efficient than their macroscale counterparts. They have their own mechanochemistry, dynamics, workspace, and usability and are composed of nature's building blocks: namely proteins, DNA, and other compounds, built atom by atom. With modern scientific capabilities it has become possible to create synthetic molecular devices and interface them with each other. Countless such machines exist in nature, and it is possible to build artificial ones by mimicking nature. Here we review some of the known molecular machines, their structures, features, and characteristics. We also look at certain devices in their early development stages, as well as their future applications and challenges.

Animals↗

PubMed2004

Chronic mucocutaneous candidiasis: a case report.

Chronic mucocutaneous candidiasis is a immuno deficiency disorder primarily due to T cell dysfunction characterized by persistent candidal infection of mucous membrane, skin, scalp and nails. Chronic mucous membrane candidiasis has an onset in infancy or childhood; the primary affected site is the oral cavity; however, lesions may occur on trunk, hands, feet and scalp. This paper describes a 12-year-old girl with candidial infection of the oral mucosa and extra oral involvement of fingers, nails, toes and intertragus area.

Antifungal Agents↗

PubMed2003

Acidogenic potential of Soya infant formula in comparison with regular infant formula and bovine milk: a plaque pH study.

Soya infant formulas are essential for infants intolerant to cow's milk. Soya formulas contains glucose syrup or maltodextrins instead of Lactose, which has led to concern that they are potentially more cariogenic than standard infant formulas containing lactose. The study was conducted to compare the acidogenic effect of Soya Infant formula, infant formula and bovine milk. The study group consisted of 75 children in the age group of 7-10 years. The plaque pH was measured using plaque pH meter, before and after rinsing with different samples for sixty minutes Soya infant formula is found to be more acidogenic than infant formula (with lactose) and bovine milk. This study demonstrates high caries inducing potential of Soya infant formula. Further awareness of the possible role of Soya infant formula in early childhood caries is required.

Analysis of Variance↗

PubMed2000

Report of the 1997 SCAROP survey on resident training. Society of Chairmen of Academic Radiation Oncology Programs.

RATIONALE AND OBJECTIVES: Members of the Society of Chairmen of Academic Radiation Oncology Programs (SCAROP) were surveyed in November 1997 to evaluate the current status of radiation oncology training in the United States and to help determine how it should be carried out in the coming decade. MATERIALS AND METHODS: A detailed questionnaire was sent to all members of SCAROP; 68 of 82 questionnaires were returned, for a response rate of 83%. RESULTS: The responses to the survey show a serious shortage of radiation oncologists in university settings, despite an apparent surplus in private practice. Although recent changes in health care have added additional clinical responsibilities for radiation oncologists in university practices, approximately 75% of the chairpersons answering the survey continue to give their faculty protected time for research. Even with additional research and teaching responsibilities, the average radiation oncologist in university practice saw 206 patients per year in 1997, a number similar to that reported by the Patterns of Care Study for radiation oncologists overall. Approximately two-thirds of respondents believe that academic chairs should strive to have all clinical faculty members participating in research. Nevertheless, most think that basic research is better performed by dedicated researchers with PhD degrees rather than radiologists with MD degrees. Most respondents believe that the training programs adequately prepare radiation oncologists for a career in academic medicine but do not provide good training in research. Eighty-four percent agreed that resident performance on the American Board of Radiology examination should be considered in the accreditation of residency programs in radiation oncology but should not be the major criterion. CONCLUSION: There is a shortage of academic radiation oncologists in the United States despite the large number of radiation oncologists completing training. This probably is due to a variety of factors, including a relatively small pool of candidates for academic positions, increasing demands for performance from academic physicians (to see more patients, perform research, publish, write grants, and teach), and competition from the private sector for recruitment of these individuals.

Data Collection↗

PubMed2000

The effects of diabetes on outcome after hip fracture.

Recent studies have suggested that patients with a history of diabetes undergoing hip fracture stabilization have higher rates of morbidity and mortality as well as poorer functional results than control groups of non-diabetics. This study was performed to evaluate the effect of diabetes on patient outcome after hip fracture. Between July 1987 and December 1996, 849 community dwelling elderly who sustained an operatively treated hip fracture were prospectively followed to determine the effect of diabetes on patient outcome. The predictor variable was the presence or absence of diabetes mellitus. Ninety-three patients (11%) had a history of diabetes. Diabetic patients were more dependent in activities of daily living and ambulation prior to hip fracture. The presence of diabetes mellitus also increased the likelihood of a patient dying during hospitalization, but had no effect on recovery of ambulatory ability or activities of daily living. Although diabetic patients have increased in-hospital mortality when compared to non-diabetic patients, patients with diabetes are just as likely to recover pre-fracture functional status as non-diabetic patients.

Activities of Daily Living↗

PubMed1999

Concurrent CMF and radiation therapy for early stage breast cancer: results of a pilot study.

PURPOSE: The optimal sequencing of chemotherapy (CT) and radiotherapy (RT) for patients with early-stage breast cancer treated with breast-conserving therapy is unresolved. Given the concerns arising from delaying either CT or RT, we conducted a pilot study of a concurrent CT-RT regimen in the hope that this would reduce side effects without decreasing efficacy. METHODS AND MATERIALS: From 1992-1994, 112 patients with 0-3 positive nodes received 6 monthly cycles of classic oral chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil (5-FU) (CMF). On day 15 of cycle 1, patients started tangential field RT (39.6 Gy in 22 fractions), followed by a 16 Gy boost in 8 fractions. Median follow-up time for surviving patients was 53 months. RESULTS: Moist desquamation developed during or shortly after RT in 50% of patients, but only 5 patients required treatment breaks. Grade 4 neutropenia during RT occurred in 16 patients, but only 1 required hospitalization. One patient developed Grade 2 radiation pneumonitis. Ninety-three percent of patients received at least 85% of prescribed drug doses. Cosmetic scores of 51 evaluable patients approximately 2 years after the end of chemotherapy were 47% excellent, 43% good, and 10% fair. We have observed 4 local failures and 20 distant failures. CONCLUSIONS: This concurrent CT-RT scheme had acceptable toxicity and outcome. Further comparison of this approach allowing prompt initiation of both CT and RT to alternative sequences is warranted.

Adult↗

PubMed1999

Hip fracture epidemiology: a review.

The incidence of hip fracture worldwide varies significantly from region to region. Numerous factors such as age, sex, race, site of residence, medical comorbidities, osseous anatomy, nutrition, smoking, and climate can affect the risk of hip fracture. Although no consensus exists for the role of all of these variables in hip fracture incidence, analysis of theses factors may result in a better understanding of hip fracture etiology and development of preventive measures.

Hip Fractures↗

PubMed1998

Hip fracture prevention: a review.

The incidence of hip fractures worldwide is expected to almost quadruple in the next 60 years. Increased cost-containment pressures will focus attention not only on improvements in hip fracture treatment but also on prevention. Three approaches that can prevent hip fractures--preventing falls, preventing and treating bone fragility, and using external hip protectors--are reviewed. Although it is impossible to prevent all hip fractures, these methods may significantly reduce the annual incidence of these fractures.

Accidental Falls↗

PubMed1996

Effect of age and caloric intake on protein oxidation in different brain regions and on behavioral functions of the mouse.

The objective of this study was to determine if oxidative stress/damage is a possible causal factor in the senescence-related loss of brain functions in the mouse. If such a relationship indeed existed, it was expected that oxidative protein damage would increase with age within regions of the brain associated with senescence-related functional loss, and that calorie restriction, an intervention which retards certain aspects of age-associated functional loss, would reverse such increases. Dietary restriction was found to retard age-associated decline of sensorimotor coordination and improve performance of aged mice on an avoidance learning problem. Protein carbonyl concentration, one measure of protein oxidation, increased from 8 to 27 months of age in most regions of the mouse brain, with the most notable increases occurring in the striatum and hippocampus, regions of the brain strongly implicated in age-associated functional loss. Age-associated loss of protein sulfhydryls was more uniform across brain regions and did not involve the hippocampus. Dietary restriction resulted in reversal of the age-associated regional trends in carbonyl and sulfhydryl concentration, with the largest changes occurring within the striatum. Cross over studies in aged calorie restricted and ad libitum fed mice indicated that lowering of carbonyl content by calorie restriction could be induced or reversed within a time frame of 3 to 6 weeks. These findings suggest that the beneficial effects of dietary restriction upon brain function and life span may depend upon its ability to acutely reduce steady-state levels of oxidative stress.

Aging↗

PubMed1996

Age-related losses of cognitive function and motor skills in mice are associated with oxidative protein damage in the brain.

The hypothesis that age-associated impairment of cognitive and motor functions is due to oxidative molecular damage was tested in the mouse. In a blind study, senescent mice (aged 22 months) were subjected to a battery of behavioral tests for motor and cognitive functions and subsequently assayed for oxidative molecular damage as assessed by protein carbonyl concentration in different regions of the brain. The degree of age-related impairment in each mouse was determined by comparison to a reference group of young mice (aged 4 months) tested concurrently on the behavioral battery. The age-related loss of ability to perform a spatial swim maze task was found to be positively correlated with oxidative molecular damage in the cerebral cortex, whereas age-related loss of motor coordination was correlated with oxidative molecular damage within the cerebellum. These results support the view that oxidative stress is a causal factor in brain senescence. Furthermore, the findings suggest that age-related declines of cognitive and motor performance progress independently, and involve oxidative molecular damage within different regions of the brain.

Aging↗

PubMed1996

Biochemical study of individual zonae from human oocytes that failed to undergo fertilization in intracytoplasmic sperm injection.

Successful intracytoplasmic sperm injection (ICSI) is dependent upon the competence of the oocyte to respond to the injection of a spermatozoon in the presence of calcium. This study determined if oocytes that failed to become fertilized (absence of any pronuclei) failed to undergo cytoplasmic activation, as ascertained by an electrophoretic shift in the zona pellucida (zona) protein, huZP2. Of 48 zonae individually analysed, 58% did not have a detectable huZP2 shift. Three patterns were observed. In seven patients, none of the unfertilized oocyte huZP2 shifted (16 out of 48); in two, all zonae exhibited a huZP2 shift (five out of 48); in eight, there was a mixture of shifted and unshifted (27 out of 48) in each case. There was no clear relationship between the presence of the huZP2 shift and maternal age, pregnancy outcome, male-factor infertility, or fertilization rate. However, in six couples diagnosed as having no detectable male-factor infertility, 73% (11 out of 15) of the zonae had unshifted huZP2, suggesting that an oocyte defect is involved in some cases of failed fertilization after ICSI. One likely cause for the absence of the huZP2 shift is a failure of cytoplasmic activation. Since oocytes were injected at metaphase II, we hypothesize that some oocytes that failed to fertilize have completed nuclear (meiotic) without cytoplasmic maturation.

Adult↗

PubMed1995

Effect of the spin-trapping compound N-tert-butyl-alpha-phenylnitrone on protein oxidation and life span.

N-tert-Butyl-alpha-phenylnitrone (PBN), a lipophilic spin-trapping compound, has been reported to decrease the concentration of protein carbonyls, the products of protein oxidation, in the brain of old gerbils to virtually the level found in the young gerbils (Carney, J. M., et al. (1991) Proc. Natl. Acad. Sci. USA 88, 3633-3636). The validity of this finding as well as that of the commonly used 2,4-dinitrophenylhydrazine procedure for the measurement of protein carbonyls was recently called into question by Cao and Cutler ((1995) Arch. Biochem. Biophys. 320, 106-114). The objective of the present study was to examine some of the relevant issues such as (a) whether the original findings on the effects of PBN can be confirmed, (b) whether similar effects of PBN occur in other species and tissues, and (c) whether PBN affects the life span of animals. Results of this study provide confirmation of the original finding that PBN indeed causes a decrease in protein carbonyl content in the gerbil brain cortex. However, a similar effect is not observed in the gerbil heart or the mouse brain cortex. Effects of PBN on protein carbonyls are thus variable depending upon tissue and species. PBN administration did not extend the life span of houseflies and at relatively high concentrations it was found to be toxic.

Aging↗

PubMed1995

A zona biochemical change and spontaneous cortical granule loss in eggs that fail to fertilize in in vitro fertilization.

OBJECTIVE: To determine the extent of biochemical changes in the zona pellucida (ZP) and cortical granule release in eggs failing to fertilize in IVF. DESIGN: After insemination, unactivated eggs without two pronuclei (PN) were studied by high resolution microscopy and fluorescent probes to determine cortical granule density and meiotic stage. After ZP isolation, proteins from individual ZPs were biotinylated, electrophoresed, and visualized by western blots with avidin-chemiluminescence. Controls included mouse unfertilized and fertilized eggs and human germinal vesicle stage oocytes and > or = 3PN eggs. SETTING: University medical center and hospital tertiary care IVF-ET program. RESULTS: Many of the unfertilized eggs were in metaphase and had relatively low cortical granule densities indicative of cortical granule loss. Approximately one half of the ZPs showed evidence of biochemical hardening with a modification of a 90 to 100 x 10(3) molecular (weight) ratio (M(r)) ZP protein. The 3PN eggs had few cortical granules and their ZPs had a pronounced 90 to 100 x 10(3) M(r) modification that was not detected in germinal vesicle stage ZP controls. CONCLUSION: The observed changes in ZP biochemistry and cortical granule quantitation demonstrate that failed fertilization is frequently associated with spontaneous cytoplasmic, but not nuclear, activation. In affected eggs, these changes could prevent fertilization in routine IVF and in cases of reinsemination. The relationship of changes in the ZP and cortical granules to infertility and in vitro culture requires further investigation. The 90 to 100 x 10(3) M(r) ZP protein modification can be detected biochemically with 1/10 of a human ZP.

Animals↗