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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 541 records · Page 30Linked to original sources
PubMed1999

Phylogeny and transpositional activity of Ty1-copia group retrotransposons in cereal genomes.

The Ty1-copia group retrotransposon populations of barley (Hordeum vulgare) and bread wheat (Triticum aestivum) have been characterised by degenerate PCR and sequence analysis of fragments of the reverse transcriptase genes. The barley population is comprised of a highly heterogeneous set of retrotransposons, together with a collection of sequences that are closely related to the BARE-1 element. Wheat also contains a highly diverse Ty1-copia retrotransposon population, together with a less prominent BARE-1 subgroup. These data have been combined with previously published Gramineae sequences to construct a composite phylogenetic tree for this class of retrotransposons in cereal grasses. The analysis indicates that the ancestral Gramineae genome contained a heterogeneous population of Ty1-copia group retrotransposons, the descendants of which have proliferated to differing degrees in present-day species. Lastly, the level of recent transpositional activity of two Ty1-copia elements has been estimated by measuring their insertional polymorphism within species. Both transposons are highly polymorphic within all species tested. These data suggest that transposition proficiency may be a common and evolutionarily stable feature of the Ty1-copia group retrotransposons of cereal grasses.

Base Sequence↗
PubMed1999

Adenocarcinoma of distal esophagus and gastroesophageal junction: long-term results of surgical treatment in a North Indian Center.

This retrospective study reports our experience managing 78 patients with adenocarcinoma of the esophagus and gastroesophageal junction operated between January 1982 and December 1996. Altogether 18 patients presented with stage I and II disease, and 60 patients had stage III and IV disease at presentation; 56 patients (71.8%) were found to have resectable disease. Of these, transhiatal esophagectomy was possible in 51 patients. Transthoracic esophagectomy was done in 3 patients, and a left thoracoabdominal approach was used in 2 patients. The stomach was used as conduit in 50 patients and the colon in 6 patients. Twenty-two patients were found to have unresectable lesions at laparotomy and underwent various palliative procedures. Overall operative mortality was 6.3%. Mortality in the resectable group was only 3.6%. Follow-up ranges from 3 to 128 months, with four patients lost to follow-up at 1, 6, 8, and 10 months. The 5-year survival of the whole group according to Kaplan and Meier survival analysis was 21.27% with a median survival of 13.48 months. Univariate analysis using the log-rank test revealed stage of the disease and resectability to be significant predictors of survival. On multivariate analysis, curative resection appeared to be the most significant predictor of survival in patients undergoing resection.

Adenocarcinoma↗
PubMed1999

Congenital pouch colon in females.

From January 1995 to March 1998, congenital pouch colon (CPC) with anorectal agenesis was diagnosed in ten girls who were classified into four groups based on the length of normal colon proximal to the colonic pouch. Of six girls with little or no normal colon, one had a cloacal anomaly while five had a colovesical or colovestibular fistula along with a completely bifid uterus and cervix and a septate vagina. Initial surgery consisted of ligation of the fistula and subtotal pouch excision with tubularization of the remaining colon in four girls, ileostomy after excision of a gangrenous pouch in one, and window colostomy in another. None of the patients had a sacral abnormality or associated major malformation. Definitive surgery using the posterior sagittal approach consisted of a pull-through of the tubularized colon in three girls (including one in whom one-stage cloacal reconstruction was performed), the ileum in one, and the proximal colon in another. The four girls with a longer length of normal colon had an associated vestibular fistula. In these, a colostomy was constructed just proximal to the pouch with definitive surgery in two patients consisting of excision of the pouch and pull-through of the proximal colon. Definitive surgery was well tolerated in all seven patients. The embryogenesis of this condition and the related genitourinary tract abnormalities are discussed.

Abnormalities, Multiple↗
PubMed1999

Inferior vesical fistula.

Exstrophy variants are uncommon developmental anomalies of the bladder; the variants involving only the bladder neck are extremely rare. There are only two case reports of inferior vesical fissure to date, and inferior vesical fistula (IVF) as an exstrophy variant has not been described previously. We report a case of IVF in a 20-month-old female. The urethra was normal in calibre and position and the bladder capacity was adequate. Simple closure of the fistula was followed by a normal micturition pattern.

Bladder Exstrophy↗
PubMed1999

The neuropsychiatry of subcortical ischemic brain disease.

The subcortical regions of the brain, by virtue of their extensive connections to neocortical and limbic structures, play an important role in the regulation of neurobehavioral functions such as mood, memory, and affect. Compromise of the blood supply to the subcortex and its connections result in behavioral syndromes that often include disturbances in cognition and mood. The extent of the underlying vascular pathology and the precise circuits compromised, in general, determine the nature of the behavioral problems. The neurobiologic mechanisms responsible for these behaviors are complex and clinical management is symptomatic and largely aimed at treating the primary clinical features with appropriate pharmacologic and behavioral approaches.

Behavior Therapy↗
PubMed1999

Somatic mutations of the L12a gene in V-kappa(1) light chain deposition disease: potential effects on aberrant protein conformation and deposition.

Light chain deposition disease (LCDD) and light chain amyloidosis (AL) are disorders of monoclonal immunoglobulin deposition in which normally soluble serum precursors form insoluble deposits in tissues. A common feature in both is the clonal proliferation of B-cells that produce pathogenic light chains. However, the deposits in LCDD differ from those in AL in that they are ultrastructurally granular rather than fibrillar and do not bind Congo red or colocalize with amyloid P component or apolipoprotein E. The reason(s) for their differences are unknown but are likely multifactorial and related to their protein conformation and their interaction with other molecules and tissue factors in the microenvironment. Knowledge of the primary structure of the light chains in LCDD is very limited. In the present study two new kappa(1) light chains from patients with LCDD are described and compared to seven other reported kappa-LCDD proteins. The N-terminal amino acid sequences of light chain GLA extracted from the renal biopsy and light chain CHO from myocardial tissue were each identical to the respective light chains isolated from the urines and to the V-region amino acid sequences translated from the cloned cDNAs obtained from bone marrow cells. The germline V-region sequences, determined from the genomic DNA in both and in MCM, a previously reported kappa(1) LCDD light chain, were identical and related to the L12a germline gene. The expressed light chains in all three exhibit amino acid substitutions that arise from somatic mutation and result in increased hydrophobicity with the potential for protein destabilization and disordered conformation.

Amino Acid Sequence↗
PubMed1999

Ultrasound guided aspiration of endometrioma--a new therapeutic modality to improve reproductive outcome.

OBJECTIVE: To evaluate the therapeutic efficacy and reproductive outcome following ultrasound guided aspiration (UGA) of endometrioma in infertile patients. METHOD: This is a prospective non-randomized clinical report of UGA in 22 infertile patients with endometrioma. The aspiration of endometriotic cysts was carried out transvaginally in nine and transabdominally in 13 patients. Following aspiration intranasal buserilin was given to eight and danazol to 14 patients. In the case of recurrence a reaspiration was done. Patients were allowed to conceive following medical therapy. Recurrence of endometrioma and conception rate was recorded and correlated with endometrioma size and volume aspirated. RESULT: A total of 47 aspirations were done. There were no procedure related complications. Reaspiration was required in six patients and one was operated (total recurrence 7/22--31.8%). During a mean follow-up of 20+/-8.4 months nine patients (40.9%) conceived and eight have already delivered at term. The recurrence risk and the conception rate was not affected by the cyst size or volume aspirated. CONCLUSION: UGA of endometrioma can be an effective and safe alternative therapeutic procedure in infertile patients with endometrioma to improve their reproductive outcome.

Adult↗
PubMed1999

Management of functional bladder neck obstruction in women: use of alpha-blockers and pediatric resectoscope for bladder neck incision.

PURPOSE: Functional bladder neck obstruction has been definitively diagnosed in the last few years due to detailed synchronous pressure flow, electromyography and video urodynamics. Clean intermittent self-catheterization and bladder neck incision are the modalities of treatment. To our knowledge the role of alpha-blockers is not yet defined in women. A new technique was developed to perform bladder neck incision using a pediatric resectoscope. MATERIALS AND METHODS: A total of 24 women with obstructive voiding symptoms or retention were evaluated with video pressure flow electromyography, and diagnosed with functional bladder neck obstruction due to high pressure and low flow on silent electromyography and bladder neck appearance on fluoroscopy. Patients were initially treated with clean intermittent self-catheterization and alpha-blockers. Catheterization was stopped when post-void residual was less than 50 ml. and only alpha-blocker therapy was continued. Bladder neck incision was performed in patients who had a poor response to or side effects of alpha-blocker therapy, or when therapy was discontinued due to economic reasons. Clean intermittent self-catheterization was continued in patients who had a poor response to alpha-blockers or refused to undergo bladder neck incision. Bladder neck incision was performed in the initial 2 cases with an adult resectoscope using a Collin's knife and subsequently a pediatric resectoscope (13F). Uroflow and post-void residual measurements were performed in all cases. RESULTS: Of the 24 patients 12 (50%) showed improvement in symptoms, peak flow and post-void residual (p <0.01) with alpha-blocker therapy only. Of the 12 patients who had a poor response to alpha-blockers 6 underwent bladder neck incision subsequently and 6 remained on clean intermittent self-catheterization. All 8 patients treated with bladder neck incision, including 2 who had a good response but discontinued alpha-blocker therapy, had sustained improvement in post-void residual and peak flow (p <0.01) after a mean followup of 3.8 +/- 2.4 years. Grade 1 stress incontinence in 2 adult resectoscope cases responded to conservative treatment. None of the pediatric resectoscope cases had stress incontinence. CONCLUSIONS: Clean intermittent self-catheterization and alpha-blockers are the initial treatment options for functional bladder neck obstruction. The alpha-blockers were successful in 50% of our patients. Bladder neck incision should be offered judiciously with minimal risk of curable stress incontinence. The pediatric resectoscope is useful to make a well controlled incision safely in the female urethra.

Adrenergic alpha-Antagonists↗
PubMed1999

Two oligosaccharides from Marsdenia roylei.

Phytochemical analysis of dried twigs of Marsdenia roylei (family Asclepiadaceae) has resulted in the isolation of a trisaccharide, maryal, and a diglycoside, rolinose. Their structures were determined as O-beta-D-oleandropyranosyl-(1-->4)-O-beta-D-digitoxopyranosyl++ +-(1-->4)-D- cymaral and ethyl O-beta-D-oleandropyranosyl-(1-->4)-O-3-O-methyl-6-deoxy-beta-D- allopyranoside, respectively, by chemical degradation and spectroscopic methods.

Carbohydrate Conformation↗
PubMed1999

Constituents of the yew trees.

Yew trees, taxonomically classified under the genus Taxus, are sources of a number of physiologically active compounds of different classes. Taxane derivatives with various carbon skeletons, lignans, flavonoids, steroids and sugar derivatives have been isolated from different Taxus species. Compounds isolated from the genus Taxus between 1908 and December 1997 have been comprehensively reviewed.

Molecular Structure↗
PubMed1999

Trisaccharides from Marsdenia roylei.

The structures of two novel trisaccharides viz. royleose and deniose isolated from Marsdenia roylei were elucidated with the help of modern physico-chemical techniques and chemical transformations. They were defined as O-beta-D-oleandropyranosyl-(1-->4)-O-beta- D-cymaropyranosyl-(1-->4)-beta-D-oleandropyranose and O-beta-D-oleandropyranosyl-(1-->4)-O-beta-D-digitoxopyranosyl++ +-(1-->4)- beta-D-oleandropyranose respectively. This is the first report on the isolation of trisaccharides of rare deoxy sugars in free state from nature.

Acetylation↗
PubMed1999

Patient-reported complications after cryoablation therapy for prostate cancer.

OBJECTIVES: To define the patient-reported complications after cryoablation therapy for prostate cancer and to compare these results to previously published patient-reported complications for radical prostatectomy and external beam irradiation. METHODS: A questionnaire similar to previously published patient-reported complication studies was sent to the first 290 patients treated by cryoablation therapy at our institution. The questionnaire was returned by 267 patients. Forty-four patients were excluded from analysis because of prior irradiation, transurethral prostatectomy, or cryoablation, resulting in a study group of 223 patients. RESULTS: Of the 208 patients with good urinary control preoperatively, 9 (4.3%) patients used incontinence pads after cryoablation. Seven of the 8 patients who used one pad daily reported leakage of only a few drops. Impotency, defined as an inability to obtain erections adequate for vaginal penetration, occurred in 85% of men who were potent preoperatively. Urethrorectal fistula occurred in 1 patient (0.4%). Bladder outlet obstruction caused by stricture or sloughed necrotic prostatic tissue required dilation or transurethral resection in 10% of patients. Scrotal swelling, penile tingling, and pelvic pain occurred in 18%, 15%, and 12% of patients, respectively; typically, these resolved spontaneously within 3 months. CONCLUSIONS: Patient-reported complications for cryoablation compared favorably to those reported for radical prostatectomy and external beam irradiation. Patient satisfaction was high; 96% of patients reported that they would choose cryosurgery as a treatment option again.

Aged↗
PubMed1999

Sezary cells with hairy projections.

A case of sezary syndrome where the sezary cells showed cytoplasmic hairy projections is reported. The patient had typical exfoliative erythematous dermatitis, high white cell count, atypical lymphocytes of T-phenotype with folded nuclei and bone marrow involvement. The ultra structure study showed cerebriform nucleus and cytoplasmic projections.

Adult↗
PubMed1999

Treatment cost of acute exacerbations of chronic bronchitis.

In 1994, the National Center for Health Statistics estimated that more than 14 million people (54 per thousand) had chronic bronchitis and sought treatment for 90.9% of their acute episodes. However, few studies have been done on the treatment cost of chronic bronchitis using national data. We conducted a retrospective analysis of claims for patients treated for acute exacerbations of chronic bronchitis (AECB) to assess the frequency of services rendered and the costs to the health care system. Records were selected for the study based on a primary diagnosis of AECB according to the International Classification of Diseases, Ninth Revision, code. Medicare was the primary source of data on patients aged > or =65 years; data from the National Healthcare and Cost Utilization Project, the National Ambulatory Medical Care Survey, and the National Hospital Ambulatory Medical Care Survey were used for patients aged <65 years. We calculated a total treatment cost of $1.2 billion for patients aged > or =65 years and $419 million for patients aged <65 years. These calculations were based on the following: 280,839 hospital discharges resulting in hospital costs of $1.1 billion for the 207,540 patients aged > or =65 years, and $408 million for the 73,299 patients aged <65 years. The mean hospital length of stay was 6.3 days with a mean cost of $5497 for patients aged > or =65 years and 5.8 days with a mean cost of $5561 for younger patients. Room and board represented the largest percentage of the mean hospital costs of AECB. Inpatient physician services cost $32 million and $11 million for the 2 age groups, respectively. Diagnosis-specific data for outpatient services were found to be less reliable than inpatient data, possibly due to diagnostic coding omissions; 331,000 outpatient office visits for AECB were found for those aged > or =65 years and 237,000 visits for those aged <65 years, resulting in respective total outpatient costs of $24.9 million and $15.1 million. If the number of outpatient visits remain consistent with 1994 levels, there would be 5.8 million visits annually for those aged > or =65 years and 4.2 million visits for those aged <65 years; total outpatient costs would be $452 million and $317 million, respectively. Because the treatment costs of AECB are largely the costs of hospitalization, any new therapy that allows more patients to be treated in the outpatient setting is likely to generate significant savings.

Aged↗
PubMed1999

bcl2 and v-abl oncogenes cooperate to immortalize murine B cells that secrete antigen specific antibodies.

In this manuscript, a general strategy was designed and used to rapidly test whether any combination(s) of p53, v-abl, bcl2 and ras oncogenes could act cooperatively to immortalize B cells. Here we report that only the combination of v-abl and bcl2 was successful. Splenic B cells from beta galactosidase-immunized mice were stimulated in vitro with lipopolysaccharide and dextran sulphate for 48 h and co-infected with ecotropic A-MuLV (v-abl) and amphotropic pZip-bcl2 (human bcl2) viruses. When inoculated i.p. into naive pristane-primed mice, these B cells generated mesenteric lymphadenopathy, intraperitoneal lymph nodules and ascites in 100% (8/8) of the mice within 36-53 days. The ascites fluid contained 69.5-122 microg/ml IgG and 2.5-13 microg/ml IgM against the immunogen. The ascites cells were passed intraperitoneally up to three times. In all passages, ascites tumors were generated, and the ascites fluid contained beta galactosidase-specific IgG and IgM, indicating that some immunoglobulin secreting B cells had been immortalized. Neither ascites nor tumors were produced when B cells infected with only one of the viruses was injected into the mice. The presence of each oncogene in ascites cells was verified by immunohistochemistry or RT-PCR. This study provides evidence for the cooperativity of an unexpected pair of oncogenes in B cell immortalization.

3T3 Cells↗
PubMed1999

Cyclosporin A regulates the levels of cyclophilin A in neuroblastoma cells in culture.

Cyclophilin A (CyP-A), a member of a highly conserved family of proteins, immunophilins, is the major intracellular receptor for the immunosuppressive drug, cyclosporin A (CsA). CyP-A is widely expressed in many tissues, but is found in the highest concentration in brain tissues and may perform critical neuronal functions. CsA is a known neurotoxin. Therefore, understanding the regulation of CyP-A levels in nerve cells, particularly by CsA, is important. We have utilized murine neuroblastoma (NB) cells as an experimental model to investigate this issue. Our results show that CsA alone was sufficient to induce morphological differentiation in undifferentiated NB cells and to increase CyP-A levels as determined by immunostaining. However, inducing terminal differentiation by elevating adenosine 3',5'-cyclic monophosphate (cAMP) levels using either 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (RO20-1724), an inhibitor of cyclic nucleotide phosphodiesterase, or prostaglandin E1 (PGE1), a stimulator of adenylate cyclase, was not sufficient to increase CyP-A levels. CsA was required to increase CyP-A levels in both RO20-1724- and PGE1-induced differentiated NB cells. Increases in CyP-A levels, however, occurred without any change in the expression of the CyP-A gene as determined by reverse-transcriptase polymerase-chain reaction analysis using (CyP-A)-specific primers. These results suggest that CsA regulates the level of its own binding protein, CyP-A, in both undifferentiated and cAMP-induced differentiated NB cells in culture.

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗
PubMed1999

Asymptomatic carotid artery stenosis associated with peripheral vascular disease: a prospective study.

This study aimed to determine the prevalence of symptomless internal carotid artery stenosis in consecutive patients presenting with peripheral vascular disease. Duplex ultrasound screening of the carotid arteries was used to determine the degree of stenosis. Co-morbidities were recorded together with age, sex and tobacco use. Internal carotid artery stenosis of > 50% was found in 35% of patients. Among these there was > or = 70% stenosis in 18% of patients and of this group 5% had an occluded carotid vessel at first presentation. Males presented with peripheral vascular disease and associated carotid stenoses at a younger age than females. Male smokers had a higher prevalence of stenosis (P = 0.036) but all smokers had developed stenoses 3-5 years before non-smokers. Females with abdominal aortic aneurysms had a greater prevalence of carotid stenosis (P = 0.037), and male aneurysmal disease diminished stenosis prevalence (P = 0.023). Men with an elevated serum creatinine were more likely to have a stenosis (P = 0.019), but not women. The other co-morbidities were not specifically associated with carotid artery stenosis.

Adult↗