Biomedical subjects
Publications and source records attributed to R Kumar.
We describe a case of parietal cephalocele. MRI and MR venography were useful for accurate anatomical depiction. We speculate on developmental pathogenesis in the context of the literature available.
Globus pharyngeus as a possible presenting symptom of a pharyngeal or upper oesophageal neoplasm is the main reason why barium swallows are requested, although it is essentially a benign disorder that in many cases requires reassurance only. We therefore retrospectively reviewed all barium swallows done in our department for globus pharyngeus during a one-year period to assess their value in the investigation of this condition. Ninety-two patients were identified. All had a normal ENT examination, and symptoms suggestive of acid reflux was the most common associated complaint, at 11 per cent. Acid reflux (18.5 per cent) and hiatus hernia (12 per cent) were the commonest findings of a barium swallow. Three cases of suspicious findings on barium swallow had a normal examination under general anaesthetic. Statistical analysis showed no significant relationship between the symptoms of globus and the barium swallow results. A barium swallow does not seem to add any further useful information to the investigation of globus pharyngeus. But most globus patients will continue to undergo a barium swallow, because although alternative investigations have been extensively assessed, it is still not clear which is the most appropriate mode of investigation for this condition.
Parathyroid hormone 1-34 [PTH(1-34)] was shown to increase transforming growth factor beta1 (TGF-beta1) and TGF-beta2 concentrations in supernatants of cultured human osteoblasts and to increase TGF-beta1 and TGF-beta2 messenger RNA (mRNA) concentrations and gene transcription in these cells. Because PTH(1-34) activates both protein kinase C (PKC) and protein kinase A (PKA) pathways in osteoblasts, we investigated the role of each kinase pathway in activation of TGF-beta isoforms. PTH(29-32), which activates the PKC pathway in rat osteoblasts, increased TGF-beta1 but not TGF-beta2 concentrations in supernatants of osteoblasts. Phorbol myristate acetate (PMA), a PKC agonist, increased TGF-beta1 but not TGF-beta2 concentrations. Specific PKC antagonists safingol and Gö6976 attenuated PTH(1-34)-mediated increases in TGF-beta1 but not TGF-beta2 synthesis. PTH(1-31), which increases PKA activity in several cell culture systems, increased TGF-beta2 but not TGF-beta1 concentrations in human osteoblast supernatants. Forskolin, a PKA agonist, increased TGF-beta2 but not TGF-beta1 concentrations in supernatants of human osteoblasts. The PKA antagonist H-89 blunted PTH(1-34)-mediated increases in TGF-beta2 but not TGF-beta1 synthesis. Our results are consistent with the concept that PTH increases TGF-beta1 expression and secretion by pathways that involve the PKC pathway, whereas it increases TGF-beta2 expression and secretion via the PKA pathway.
Homeostasis in normal tissue is regulated by a balance between proliferative activity and cell loss by apoptosis. Apoptosis is a physiological mechanism of cell loss that depends on both pre-existing proteins and de novo protein synthesis, and the process of apoptosis is integral to normal mammary gland development and in many diseases, including breast cancer. The mammary gland is one of the few organ systems in mammals that completes its morphologic development postnatally during two discrete physiologic states, puberty and pregnancy. The susceptibility of the mammary gland to tumorigenesis is influenced by its normal development, particularly during stages of puberty and pregnancy that are characterized by marked alterations in breast cell proliferation and differentiation. Numerous epidemiologic studies have suggested that specific details in the development of the mammary gland play a critical role in breast cancer risk. Mammary gland development is characterized by dynamic changes in the expression profiles of Bcl-2 family members. The expression of Bcl-2 family proteins in breast cancer is also influenced by estradiol and by progestin. Since the ratio of proapoptotic to antiapoptotic proteins determines apoptosis or cell survival, hormone levels may have important implications in the therapeutic prevention of breast cancer.
UNLABELLED: The addition of a brief alpha interferon regimen to each CHOP induction cycle, plus one year of alpha interferon thrice weekly maintenance therapy, has no early effect on response rates or survival in patients with Intermediate or High grade cell NHL. BACKGROUND: The CHOP (Cyclophosphamide, Adriamycin. Vincristine, Prednisone) regimen is the most widely used first-line therapy for patients with Intermediate or High Grade (IG/HG) non-Hodgkin's lymphoma (NHL). Alpha 2b interferon (INF) enhances response rates and improves survival in low-grade NHL. The International Oncology Study Group (IOSG) conducted a prospective randomized study comparing CHOP alone or combined with INF in patients with IG/HG-NHL. The primary study aim was to compare the objective response rates in these patient cohorts. PATIENTS AND METHODS: Patients with a confirmed diagnosis of measurable NHL of International Working Formulation (IWF) groups D to H histology were randomized to receive CHOP alone or CHOP with 5Mu INF s.c. for 5 days on days 22 to 26 of each 28 day cycle with INF 5 million units (Mu) given three times per week subcutaneously for 52 weeks in those patients who responded to CHOP plus INF. RESULTS: The overall response rates were equivalent in both groups: CHOP alone (214 patients) 81% (complete 55%, partial 26%); CHOP plus INF (221 patients) 80% (complete 54%, partial 26%). At 36 months, the actuarial survival rate was equivalent in both groups. CONCLUSIONS: There is no apparent early advantage in terms of response or survival conferred by adding the study INF regimen to CHOP therapy for patients with IG/HG-NHL.
The objective of this study was to determine the role of cytoplasmic (protein kinase-like homology and guanylyl cyclase catalytic) domains of atrial natriuretic peptide (ANP) receptor-A (Npra) in postbinding events and metabolic turnover of ligand-receptor complexes. Using deletion mutagenesis, the specific regions in the intracellular domains of Npra relevant to the receptor function, namely ligand-binding, cGMP production, and internalization and sequestration of ligand-receptor complexes, have been determined in transiently expressing COS-7 cells. Deletion of 12 aa (aa) at the carboxyl-terminal end of receptor (Delta1045-Npra) affected neither ligand-binding efficiency nor cGMP production. However, deletion of 120 to 170 aa residues (Delta937-Npra, Delta916-Npra, Delta902-Npra, and Delta887-Npra) decreased ligand binding by 16 to 20% and cGMP production by 50 to 90%. Further deletion of 422 aa and 569 aa (Delta635-Npra and Delta488-Npra) reduced ligand binding efficiency by 40% and 90%, respectively. The deletion of 12 aa (Delta1045-Npra) did not affect the internalization of Npra; however, deletions up to 170 aa (Delta937-Npra, Delta916-Npra, Delta887-Npra) reduced the internalization of ligand-receptor complexes by 60%. Cells expressing either full-length (wild-type) Npra or 120 aa deleted receptor (Delta937-Npra) released 40 to 45% (125)I-ANP radioactivity into culture medium, but only 10 to 15% radioactivity was released from the cells that expressed Delta635-Npra. Furthermore, 35 to 40% (125)I-ANP radioactivity was detected into the intracellular compartments of cells that expressed the wild-type Npra, and only 5 to 10% (125)I-ANP radioactivity was observed in cells expressing the Delta635-Npra (-422 aa) or Delta488-Npra (-569 aa) mutant receptors. These results show that specific regions within the intracellular domains of Npra determine the extent of ligand-binding efficiency, cGMP production, endocytosis, and intracellular sequestration of ligand-receptor complexes in cDNA expressing COS-7 cells.
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Association of syringomyelia with retrocerebellar arachnoid cysts is rare. A case of 14 year old female is being reported, who presented with hydrocephalus caused by a large midline retrocerebellar infravermal arachnoid cyst leading to obstruction of the outlet foramina of the fourth ventricle. There was associated syringomyelia. The pathogenesis of syringomyelia is discussed. The need to evaluate cervical spinal cord by taking T1 weighted sagittal sections in all the patients of large posterior fossa mass lesions causing obstruction to the outlet foramina of the fourth ventricle has been stressed, in order to detect associated syringomyelia.
PURPOSE: We describe, define and evaluate the role of retroperitoneoscopic nephrectomy for tuberculous nonfunctioning kidneys, and compare the results with those of open nephrectomy in similar cases in a nonrandomized study. MATERIALS AND METHODS: Beginning in July 1994, 9 patients underwent retroperitoneoscopic nephrectomy for tuberculous nonfunctioning kidneys at our center. Data obtained from the records of these patients were compared with those of 9 who underwent open nephrectomy for a similar indication during the same period. Retroperitoneoscopic nephrectomy was initially performed by kidney dissection followed by ligation of the hilar vessels. The technique was subsequently modified and the vessels controlled before dissecting the kidney. Various parameters were compared and statistical analysis was done. RESULTS: The 2 groups were similar in regard to patient age, gender and side of disease. Retroperitoneoscopic nephrectomy was successful in 7 of the 9 patients. Although 2 of our initial patients required conversion to open surgery, the remaining 7 successfully underwent retroperitoneoscopic nephrectomy after modifying the technique. Mean operative time was slightly greater in the retroperitoneoscopy than in the open surgery group (103.3 versus 92.2 minutes). Mean blood loss was less in the retroperitoneoscopy group (101.4 versus 123.3 ml.), mean hospital stay plus or minus standard deviation was significantly shorter (3.2 +/- 0.83 versus 8.88 +/- 3.37 days) and mean time to return to work was significantly less (3 versus 7 weeks). Mean analgesic requirement for opioids and diclofenac sodium was also lower in the retroperitoneoscopic nephrectomy group (0 versus 1.44 +/- 0.72 and 3.8 +/- 1.3 versus 4.3 +/- 1.2 doses, respectively). Minor complications developed in only 2 retroperitoneoscopy cases. CONCLUSIONS: Tuberculosis has been considered a contraindication to retroperitoneoscopic nephrectomy due to a high conversion rate. However, we believe that our modified technique of retroperitoneoscopic nephrectomy is a viable option for managing tuberculous nonfunctioning kidneys. The conversion rate is lower than previously reported. Comparing our results with those of open nephrectomy shows that retroperitoneoscopic nephrectomy is beneficial in all respects except for slightly longer operative time. Because of the benefits of minimally invasive surgery, this approach should be considered in such cases.
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Peduncular hallucinations are formed visual images often associated with sleep disturbance and are caused by lesions in the midbrain, pons and diencephalon. In present case report, a four year child, who was operated for midline posterior fossa medulloblastoma developed peduncular hallucinations on 3rd post operative day. Traction trauma or the compression of mid brain was thought to be the most possible cause of hallucinations.
Effect of acute and chronic administration of L-arginine on morphine induced gastrointestinal inhibition was tested in rats. In the test for acute effect, L-arginine (200 mg/kg, i.v.) was given 10 minutes before the charcoal meal test. In the test for chronic effects, L-arginine (200 mg/kg, i.v.) was given twice a day for 4 days. Charcoal meal test was done on the fifth day. Morphine was administered 45 minutes before the charcoal meal test. Results showed that acute administration of L-arginine did not affect the morphine's action on the GIT. In contrast, chronic administration of L-arginine reversed the morphine induced decrease in gastrointestinal motility. The reversal was however, not complete. This data suggests that inhibition of NO may be one of the mechanism of morphine induced constipation.
The heat exposure for working conditions in coastal areas of tropical and subtropical countries like India is a crucial factor in improved qualitative and quantitative production. The hot climate augments the heat exposure close to sources like furnaces. In the present work heat exposure to workers in glass manufacturing units in a coastal area of India has been assessed. The Wet Bulb Globe Temperature (WBGT), the Corrected Effective Temperature (CET) and Mean Radiant Temperature (MRT) were measured. The WBGT values much exceeded ACGIH TLVs. A revision of these standards to suit tropical and subtropical conditions is required. The recommended durations of work and rest have been estimated.
The variations in peritoneal equilibration test (PET) characteristics in various ethnic groups have been reported. Data are scarce regarding the pattern of membrane characteristics in Indian patients. The factors affecting PET and the PET, in turn, affecting patient outcome are controversial issues. We prospectively analyzed 41 patients to evaluate: (1) the pattern of PET characteristics in Indian patients; (2) the factors affecting the PET; (3) the effect of membrane characteristics on patient outcome. The mean period of follow up was 17.1 +/- 9.3 months. The PET results revealed 21 high transporters (51%), 13 high-average transporters (32%), 6 low-average transporters (15%), and 1 low transporter (2%). The distribution of the various PET categories in patients below the age of 60 years and those 60 years or above was not significant (p = 0.70). The sex distribution (p = 0.94) and prevalence of diabetes (p = 0.62) were not significantly different in various PET categories. On regression analysis, PET values were not affected by the age of patients (beta = 0.80, p = 0.61). Patient survival among high and high-average transporters was significantly less compared with low and low-average transporters (p = 0.01). We conclude that Indian patients on continuous ambulatory peritoneal dialysis (CAPD) have a higher proportion of high and high-average transporters. The pattern of membrane kinetics cannot be explained by differences in patient characteristics and diabetic status. Patients with high PET values have poorer patient survival on CAPD.
In a cluster sample survey in rural areas of Punjab visual outcome after cataract surgery was assessed. Three hundred patients (428 cataract operated eyes) were included in the study from 24 sampled villages. The mean age at cataract extraction was 61.70 +/- 9.82 years. The average interval since the cataract surgery was 7.05 +/- 5.86 years (range 0.11-32 years). Of the 428 operated eyes, 72 (16.82%) were blind (VA < 3/60), 162 (37.85%) had low visual acuity (VA 3/60-< 6/18) and 194 (45.33%) eyes gained good visual acuity (VA > or = 6/18). Cataract surgery related complications were the principal causes leading to blindness in 50 of 72 eyes; these included corneal oedema, (17/72;23.3%), retinal detachment (14/72;19.4%), and aphakic glaucoma (13/72;18.05%). This study emphasizes the need to improve the qualitative aspect of cataract surgery including long-term follow up in rural India.
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