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Biomedical subjects

R Agarwal

Publications and source records attributed to R Agarwal.

At least 181 records · Page 10Linked to original sources
PubMed1998

Atrial escape capture bigeminy.

Atrial escape capture bigeminy is a rare electrocardiographic entity. A case of atrial escape sinus capture presenting as true atrial bigeminy is reported.

Aged↗
PubMed1998

Production of cytotoxic factor by peripheral blood mononuclear cells (PBMC) in patients with dengue haemorrhagic fever.

A unique cytokine, human cytotoxic factor (hCF), has been shown to occur in the sera of patients with dengue fever (DF) and dengue haemorrhagic fever (DHF). The present study was undertaken to investigate the ability of fresh PBMC of such patients to produce hCF. The PBMC were cultured for 24 h and the culture supernatants (CS) were analysed for the presence of hCF by cytotoxicity assay, competitive ELISA and dot blot tests. In 90% of 246 cases CS were positive for hCF by the three tests. CS were positive for hCF in PBMC collected from days 1-20 of illness but not at later periods. Higher cytotoxic activity was observed in CS of days 1-4 of illness and was highest in cases of DHF grade IV and lowest in cases of DF. Dot blot hybridization of RNA extracted from the PBMC of the patients showed the presence of mRNA for hCF in 94% of cases. A similar number of patients showed the presence of hCF in situ in the PBMC smears by fluorescent antibody technique. hCF was found only in CD4+ T cells. The findings thus present direct evidence of the production of hCF by CD4 T cells of cases of DF/DHF.

Cytokines↗
PubMed1998

Improvement of intraoperative somatosensory evoked potentials by ketamine.

Many anaesthetics effect the latency and amplitude of somatosensory evoked potentials (SSEP). We present a patient who underwent two anterior/posterior spine fusions (A/PSF) at age 11 and 12 years old after resection of a spinal astrocytoma. She did have residual neurologic deficits of her lower extremities. SSEPs were unobtainable during the first surgery using an opioid-based anaesthetic. A ketamine-based anaesthetic was used for the second surgery and SSEPs were easily monitored. No other factors seem to have changed between the two surgeries. The anaesthetic management during each procedure is reviewed and the contributions of other factors to SSEP monitoring discussed.

Anesthetics, Dissociative↗
PubMed1998

Nasal sill augmentation in adult incomplete cleft lip nose deformity using superiorly based turn over orbicularis oris muscle flap: an anatomic approach.

Adult incomplete cleft lip nose deformity is not uncommon in India. Poverty, ignorance, and parental neglect account for its late presentation. Besides the classical features of cleft lip nose deformity, the constant findings observed in this patient population have been a widened and depressed nasal sill. This is attributable to the sparse, hypoplastic, and abnormally orientated orbicularis oris muscle in the region of the sill. Failure to restore the nasal sill symmetry by suitably augmenting the sill frequently leads to unsatisfactory and asymmetric results. However, in the literature, satisfactory restoration of the nasal sill has not been given the importance it deserves while performing cleft lip rhinoplasty. We present a method of augmenting the depressed nasal sill in cases of adult incomplete nose deformity using a superiorly based orbicularis oris muscle flap, which is harvested from the soft tissues between the apex of the cleft and the nostril sill. Following de-epithelialization of the overlying skin, the exposed muscle is raised as a superiorly based flap after dissecting it from the underlying mucosa. It is folded, turned over, and tucked into the nasal sill base and anchored to the anterior nasal spine to give the desired augmentation. Satisfactory results have been obtained in 18 cases of nasal deformity associated with incomplete cleft lip. In our opinion, this technique offers a simple and effective method of augmenting the depressed sill by utilizing locally available tissues and without the need for procuring autologous tissue from distant sites.

Adolescent↗
PubMed1998

Pulsed Doppler echocardiographic study of left ventricular diastolic function in patients with idiopathic dilated cardiomyopathy.

Dilated cardiomyopathy is basically regarded as a disease of left ventricular systolic dysfunction. There are only a few studies evaluating diastolic function in patients with dilated cardiomyopathy. To assess the LV diastolic function, 25 patients with idiopathic dilated cardiomyopathy and 20 age and sex matched normal subjects were studied with transmitral spectral tracings derived from pulsed Doppler echocardiography. All cardiomyopathy patients were in New York Heart Association class III to IV with dilated left ventricles and reduced systolic function (mean ejection fraction of 36.6 +/- 6.7 Vs 65 +/- 6 in normal subjects, p < 0.001). Patients with cardiomyopathy demonstrated an increased ratio of early to late diastolic velocity (E/A) (1.89 +/- 0.59 Vs 1.50 +/- 0.27 m/sec, p < 0.05), short deceleration time (E-E/2) (57.05 +/- 13.36 Vs 70.20 +/- 16.56 msec, p < 0.01) and short isovolumic relaxation time (IVRT) (53.5 +/- 22.7 Vs 72 +/- 12 msec, p < 0.05) as compared to normal subjects. The early filling fraction (EFF) was higher (0.71 +/- 0.11 Vs 0.66 +/- 0.06, p < 0.05) and atrial filling fraction (AFF) was lower (0.28 +/- 0.11 Vs 0.33 +/- 0.06, p < 0.05) in cardiomyopathy patients than in normal subjects. Our observations in a select group of dilated cardiomyopathy patients with advanced disease demonstrate a restrictive pattern on pulsed Doppler echocardiography.

Adult↗
PubMed1998

Elective coronary artery stenting--immediate and follow up results.

Elective coronary artery stenting was performed in 242 consecutive patients in our centre for complex lesions (Type B, C), proximal lesions, restenotic lesions, total occlusion and venous grafts. The procedural success rate was 94.21%. Three patients (1.23%) required emergency coronary artery bypass surgery. Acute and sub-acute thrombosis rate was 1.26% and 4.13%, respectively. There was one in-hospital death (0.41%). 164 patients were followed up clinically for a mean period of 11 +/- 6 months (range 1 month to 30 months). Angiographic follow up was done in 68 patients with a restenosis rate of 16.17%.

Adult↗
PubMed1998

Anticarcinogenic effect of a flavonoid antioxidant, silymarin, in human breast cancer cells MDA-MB 468: induction of G1 arrest through an increase in Cip1/p21 concomitant with a decrease in kinase activity of cyclin-dependent kinases and associated cyclins.

There is an increasing interest in identifying potent cancer preventive and therapeutic agents against breast cancer. Silymarin, a flavonoid antioxidant isolated from milk thistle, exerts exceptionally high to complete anticarcinogenic effects in tumorigenesis models of epithelial origin. In this study, we investigated the anticarcinogenic effect of silymarin and associated molecular mechanisms, using human breast carcinoma cells MDA-MB 468. Silymarin treatment resulted in a significantly high to complete inhibition of both anchorage-dependent and anchorage-independent cell growth in a dose- and time-dependent manner. The inhibitory effects of silymarin on cell growth and proliferation were associated with a G1 arrest in cell cycle progression concomitant with an induction of up to 19-fold in the protein expression of cyclin-dependent kinase (CDK) inhibitor Cip1/p21. Following silymarin treatment of cells, an incremental binding of Cip1/p21 with CDK2 and CDK6 paralleled a significant decrease in CDK2-, CDK6-, cyclin D1-, and cyclin E-associated kinase activity with no change in CDK2 and CDK6 expression but a decrease in G1 cyclins D1 and E. Taken together, these results suggest that silymarin may exert a strong anticarcinogenic effect against breast cancer and that this effect possibly involves an induction of Cip1/p21 by silymarin, which inhibits the threshold kinase activities of CDKs and associated cyclins, leading to a G1 arrest in cell cycle progression.

Anticarcinogenic Agents↗
PubMed1998

Cultured human trabecular meshwork cells express functional growth factor receptors.

PURPOSE: To compare the mRNA expression of growth factor receptors in cultured human trabecular meshwork (HTM) cells with ex vivo HTM tissues and to determine whether HTM cells generate a physiologic response after exposure to exogenous growth factors. METHODS: The reverse transcription-polymerase chain reaction (RT-PCR) method was used to detect the expression of various growth factor receptor mRNAs using early passaged, cultured HTM cells from donors of several ages. RT-PCR on ex vivo HTM tissues from healthy donors and donors with glaucoma were also used to compare and contrast mRNA expression with cell culture results. After the exogenous administration of growth factors, cell proliferation and extracellular acidification rate studies were used to measure the functional responses of HTM cells to growth factors. RESULTS: Amplification products of the expected size for 15 growth factor receptors were detected in cultured HTM cells and in ex vivo HTM tissues. The administration of exogenous growth factors showed that (a) hepatocyte growth factor (HGF), epidermal growth factor (EGF), insulinlike growth factor (IGF)-1, tumor necrosis factor (TNF) alpha, platelet-derived growth factor (PDGF)-AA, PDGF-BB, PDGF-AB, and basic fibroblast growth factor (FGF-2) stimulated cell proliferation, whereas FGF-1 (acidic), transforming growth factor (TGF) alpha, interleukin (IL)-1alpha, nerve growth factor (NGF), and FGF-7 (keratinocyte growth factor [KGF]) had no significant influence on cell proliferation; (b) TGF-beta isoforms significantly inhibited EGF-stimulated trabecular meshwork cell proliferation; and (c) FGF-1 (acidic), TGF-alpha, EGF, IL-1alpha, IL-1beta, HGF, TNF-alpha, PDGF-AA, and IGF-1 significantly stimulated extracellular acidification, whereas FGF-2 (basic), FGF-7 (KGF), TGF-beta1-beta3 and NGF had no significant influence on extracellular acidification. CONCLUSIONS: These studies show that mRNA for numerous growth factor receptors can be detected in cultured HTM cells and in ex vivo HTM tissues. They also show that many of the receptors are functional, because exogenous growth factor administration elicits a physiologic response. In vivo, these receptors may be activated by growth factors present within the aqueous humor (aquecrine/paracrine) or by growth factors synthesized and released locally by trabecular meshwork cells themselves (autocrine). Specific growth factors acting through high-affinity receptors may be involved in maintaining the normal microenvironment of the HTM and also may be involved in the pathogenesis of primary open-angle glaucoma.

Adolescent↗
PubMed1998

Carbodi-imide coupling of enzymes to the reversibly soluble insoluble polymer Eudragit S-100.

The coupling of proteins and enzymes to soluble-insoluble polymers by carbodi-imide can be performed by using numerous variations of the protocol. This protocol has been investigated for the coupling of five different enzymes, namely wheatgerm acid phosphatase, beta-glucosidase, beta-galactosidase, trypsin and xylanase, to an enteric methacrylate polymer Eudragit S-100. The following results were found. (1) The activity of the bioconjugate was critically dependent on the physical state of the polymer and the pH of the coupling reaction. For example, in the case of wheatgerm acid phosphatase, the activity of the bioconjugate was 49% when coupling was performed at pH 7.2 and 67% when coupling was performed at pH 4. 5. With beta-galactosidase the corresponding values were 57% and 23% and with beta-glucosidase they were 57% and 52% respectively. (2) In some cases, such as beta-glucosidase and beta-galactosidase, it might be necessary to remove excess carbodi-imide before the addition of the enzyme to the activated matrix. (3) In most of the cases investigated, a sig-nificant amount of the enzyme (more than 90%) could be bound to the matrix merely by adsorption. (4) More importantly, after the carbodi-imide coupling procedure, a sufficient fraction of the bound enzyme could be eluted off the matrix, indicating that this was merely adsorbed and not covalently coupled.

Acid Phosphatase↗
PubMed1997

Green tea constituent epigallocatechin-3-gallate and induction of apoptosis and cell cycle arrest in human carcinoma cells.

BACKGROUND AND PURPOSE: The polyphenolic compounds present in green tea show cancer chemopreventive effects in many animal tumor models. Epidemiologic studies have also suggested that green tea consumption might be effective in the prevention of certain human cancers. We investigated the effect of green tea polyphenols and the major constituent, epigallocatechin-3-gallate, on the induction of apoptosis (programmed cell death) and regulation of cell cycle in human and mouse carcinoma cells. METHODS: Human epidermoid carcinoma cells (cell line A431), human carcinoma keratinocyte (cell line HaCaT), human prostate carcinoma cells (cell line DU145), mouse lymphoma cells (cell line L5178Y), and normal human epidermal keratinocytes (NHEKs) were used. Apoptosis was assessed by 1) the formation of internucleosomal DNA fragments by agarose gel electrophoresis, 2) confocal microscopy, and 3) flow cytometry after tagging the DNA fragments by fluorescence label. The distribution of cells in different phases of the cell cycle was analyzed by flow cytometry. RESULTS: Treatment of A431 cells with green tea polyphenols and its components, epigallocatechin-3-gallate, epigallocatechin, and epicatechin-3-gallate, resulted in the formation of internucleosomal DNA fragments, characteristic of apoptosis. Treatment with epigallocatechin-3-gallate also resulted in apoptosis in HaCaT, L5178Y, and DU145 cells, but not in NHEK. Confocal microscopy and flow cytometry confirmed the findings. The DNA cell cycle analysis showed that in A431 cells, epigallocatechin-3-gallate treatment resulted in arrest in the G0-G1 phase of the cell cycle and a dose-dependent apoptosis. CONCLUSIONS: Green tea may protect against cancer by causing cell cycle arrest and inducing apoptosis. It needs to be evaluated in human trials.

Animals↗
PubMed1997

Novel cancer chemopreventive effects of a flavonoid antioxidant silymarin: inhibition of mRNA expression of an endogenous tumor promoter TNF alpha.

In this study we describe exceptionally high protective effects of silymarin, a flavonoid antioxidant isolated from milk thistle, against 12-O-tetradecanoylphorbol 13-acetate (TPA)- and okadaic acid (OA)-caused tumor promotion in SENCAR mouse skin. Pre-application of silymarin to that of TPA in 7, 12-dimethylbenz(a)anthracene (DMBA)-initiated mouse skin resulted in almost complete protection in terms of tumor incidence (85%) as well as multiplicity (94%). In OA-caused tumor promotion studies, application of silymarin prior to that of OA in DMBA-initiated mouse skin resulted in a complete protection against tumorigenicity. We next assessed the effect of silymarin on TPA- and OA-caused induction of mRNA expression of tumor necrosis factor alpha (TNF alpha) which is an endogenous tumor promoter and a central mediator of tumor promotion in vivo in the case of both TPA and OA tumor promotion. Topical application of silymarin on mouse skin prior to that of TPA or OA resulted in a highly significant to complete inhibition in a dose-dependent manner against both TPA- and OA-caused induction of TNF alpha mRNA expression in mouse epidermis. These results indicate that silymarin exerts novel chemopreventive effects against tumorigenicity by inhibiting endogenous tumor promoter TNF alpha. Additional studies are warranted in other tumor models to further evaluate the cancer chemopreventive effect of silymarin and to define the involvement of TNF alpha as a molecular target for such an effect.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1997

Mechanism of differential efficacy of garlic organosulfides in preventing benzo(a)pyrene-induced cancer in mice.

The mechanism of differential efficacies of diallyl sulfide (DAS), diallyl disulfide (DADS), diallyl trisulfide (DATS), dipropyl sulfide (DPS) and dipropyl disulfide (DPDS) in preventing benzo(a)pyrene (BP)-induced cancer in mice has been investigated by determining their effects on the enzymes of BP activation/inactivation pathways. With the exception of DATS, treatment of mice with other organosulfides (OSCs) caused a small but significant increase (37-44%) in hepatic ethoxyresorufin O-deethylase (EROD) activity. However, the forestomach EROD activity did not differ significantly between control and treated groups. Only DAS treatment caused a modest but statistically significant reduction (about 25%) in pulmonary EROD activity. These results suggest that while reduction of EROD activity may, at least in part, contribute to the DAS-mediated inhibition of BP-induced lung cancer, anticarcinogenic effects of OSCs against BP-induced forestomach carcinogenesis seems to be independent of this mechanism. Treatment of mice with DAS, DADS and DATS resulted in a significant increase, as compared with control, in both hepatic (3.0-, 3.2- and 4.4-fold, respectively) and forestomach (1.5-, 2.7- and 2.7-fold, respectively) glutathione transferase (GST) activity toward anti-7beta,8alpha-dihydroxy-9alpha,10alpha-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene (anti-BPDE), which is the ultimate carcinogen of BP. The pulmonary GST activity was not increased by any of the OSCs. Even though epoxide hydrolase (EH) activity was differentially altered by these OSCs, a correlation between chemopreventive efficacy of OSCs and their effects on EH activity was not apparent. The results of the present study suggest that differences in the ability of OSCs to modulate GST activity toward anti-BPDE may, at least in part, account for their differential chemopreventive efficacy against BP-induced cancer in mice.

Allyl Compounds↗