PubMed Health⌕ Search

Biomedical subjects

S K Gupta

Publications and source records attributed to S K Gupta.

At least 559 records · Page 31Linked to original sources
PubMed1990

Changing arteriosclerotic disease patterns and management strategies in lower-limb-threatening ischemia.

From January 1, 1974 to December 31, 1989, we treated 2829 patients with critical lower-extremity ischemia. In the last 5 years, 13% of patients had therapeutically significant stenoses or occlusions above and below the groin, while 35% had them at two or three levels below the inguinal ligament. Unobstructed arterial flow to the distal half of the thigh was present in 26% of patients, and 16% had unobstructed flow to the upper third of the leg with occlusions of all three leg arteries distal to this point and reconstitution of some patent named artery in the lower leg or foot. In the last 2 years, 99% of all patients with a threatened limb and without severe organic mental syndrome or midfoot gangrene were amenable to revascularization by percutaneous transluminal angioplasty (PTA), arterial bypass, or a combination of the two, although some distal arteries used for bypass insertion were heavily diseased or isolated segments without an intact plantar arch. Limb salvage was achieved and maintained in more than 90% of recent patient cohorts, with a mean procedural mortality rate of 3.3%. Recent strategies that contributed to these results include (1) distal origin short vein grafts from the below-knee popliteal or tibial arteries to an ankle or foot artery (291 cases); (2) combined PTA and bypass (245 cases); (3) more distal PTA of popliteal and tibial artery stenoses (233 cases); (4) use of in situ or ectopic reversed autogenous vein for infrapopliteal bypasses, even when vein diameter was 3 to 4 mm; (5) composite-sequential femoropopliteal-distal (PTFE/vein) bypasses; (6) reintervention when a procedure thrombosed (637 cases) or was threatened by a hemodynamically significant inflow, outflow, or graft lesion (failing graft, 252 cases); (7) frequent follow-up to detect threatening lesions before graft thrombosis occurred and to permit correction of lesions by PTA (58%) or simple reoperation; and (8) unusual approaches to all infrainguinal arteries to facilitate secondary operations, despite scarring and infection. Primary major amputation rates decreased from 41% to 5% and total amputation rates decreased from 49% to 14%. Aggressive policies to save threatened limbs thus are supported.

Amputation, Surgical↗
PubMed1990

Microcomputer database and system of audit for the vascular surgeon.

We have set up a vascular database based upon an IBM personal computer in the vascular unit at Repatriation General Hospital, Concord, using 'Dataease'. This is commercially available software that allows the development of a database by users with little or no programming knowledge. The database is menu driven and designed to record details of admissions, indications for surgery, operations, complications and follow-up and has been set up as a prospective project from 1 January 1989 after a pilot study in 1988. Currently, interns, residents and registrars enter data directly onto the computer, providing an excellent teaching and review medium. Unit audit is easy as the program is completely menu driven and there are more than 100 customized reports written, ranging from providing simple complication details to complex reports deriving graft cumulative patency rates. This system also provides for 'instant' discharge letters which have markedly improved communication with the general practitioner.

Hospital Information Systems↗
PubMed1990

Parovarian cystadenocarcinoma: a case report.

Although primary ovarian carcinomas are frequent, carcinomas having a primary origin in parovarian cysts are extremely rare. The majority of neoplasms developing in parovarian cysts are benign serous tumours. Only 9 cases of parovarian adenocarcinoma have been reported so far in the world literature. Out of these 6 have been of low grade malignancy. Of the rest 3 cases also, only one was invasive. The case described here appears to be the second case of parovarian adenocarcinoma which was invasive. The origin of this tumour is discussed together with a brief review of literature on adenocarcinomas of parovarian origin.

Cystadenocarcinoma↗
PubMed1990

Mutation of the Gs protein alpha subunit NH2 terminus relieves an attenuator function, resulting in constitutive adenylyl cyclase stimulation.

G-proteins couple hormonal activation of receptors to the regulation of specific enzymes and ion channels. Gs and Gi are G-proteins which regulate the stimulation and inhibition, respectively, of adenylyl cyclase. We have constructed two chimeric cDNAs in which different lengths of the alpha subunit of Gs (alpha s) have been replaced with the corresponding sequence of the Gi alpha subunit (alpha i2). One chimera, referred to as alpha i(54)/s' replaces the NH2-terminal 61 amino acids of alpha s with the first 54 residues of alpha i. Within this sequence there are 7 residues unique to alpha s, and 16 of the remaining 54 amino acids are nonhomologous between alpha i and alpha s. The second chimera, referred to as alpha i/s(Bam), replaces the first 234 amino acids of alpha s with the corresponding 212 residues of alpha i. Transient expression of alpha i(54)/s in COS-1 cells resulted in an 18- to 20-fold increase in cyclic AMP (cAMP) levels, whereas expression of either alpha i/s(Bam) or the wild-type alpha s polypeptide resulted in only a 5- to 6-fold increase in cellular cAMP levels. COS-1 cells transfected with alpha i showed a small decrease in cAMP levels. Stable expression of the chimeric alpha i(54)/s polypeptide in Chinese hamster ovary (CHO) cells constitutively increased both cAMP synthesis and cAMP-dependent protein kinase activity. CHO clones expressing transfected alpha i/s(Bam) or the wild-type alpha s and alpha i cDNAs exhibited cAMP levels and cAMP-dependent protein kinase activities similar to those in control CHO cells. Therefore, the alpha i(54)/s chimera behaves as a constitutively active alpha s polypeptide, whereas the alpha i/s(Bam) polypeptide is regulated similarly to wild-type alpha s. Expression in cyc-S49 cells, which lack expression of wild-type alpha s, confirmed that the alpha i(54)/s polypeptide is a highly active alpha s molecule whose robust activity is independent of any change in intrinsic GTPase activity. The difference in phenotypes observed upon expression of alpha i(54)/s or alpha i/s(Bam) indicates that the NH2-terminal moieties of alpha s and alpha i function as attenuators of the effector enzyme activator domain which is within the COOH-terminal half of the alpha subunit. Mutation at the NH2 terminus of alpha s relieves the attenuator control of the Gs protein and results in a dominant active G-protein mutant.

1-Methyl-3-isobutylxanthine↗
PubMed1990

Fine needle aspiration cytology of rectal masses.

This paper describes the results of transproctoscopic fine needle aspiration cytology in the diagnosis of rectal lesions. Fifty one consecutive patients referred with a presumptive diagnosis of rectal mass were subjected to proctoscopic examination when fine needle aspiration cytology, brush cytology and biopsy samples were taken. Of the 30 patients of malignancy of rectum in whom all the three sampling techniques were applied, the biopsy was positive in 27 (90%), brush cytology in 25 (83.3%) and fine needle aspiration cytology in 29 (96.6%). A combination of fine needle aspiration cytology with brush cytology gave a positive yield in 96.6% while that fine needle aspiration cytology with brush cytology gave a yield of 100%. Fine needle aspiration cytology was most helpful in infiltrative tumours. All 10 patients with secondaries in the pouch of Douglas or rectovesical pouch, and the single patient with submucosal rectal carcinoma were correctly diagnosed at fine needle aspiration cytology. There were no false positive results with fine needle aspiration cytology and no complications were encountered with the procedure.

Adenocarcinoma↗
PubMed1990

Myelin-associated glycoprotein gene expression in the presence and absence of Schwann cell-axonal contact.

The distal segments of the crush-injured and permanently transected sciatic nerve provide models to study Schwann cell activity in the presence and absence of Schwann cell-axonal contact, respectively. We examined the quantity and quality of transcript coding for the myelin-associated glycoprotein (MAG) over a 3-week period following crush injury and at 35 days after transection to investigate possible regulation of this gene during nerve injury and subsequent repair. Northern blot and slot blot analysis indicated a sharp decrease in levels of MAG mRNA 2 days after crush injury which was followed by a progressive increase in levels of message between 7 and 21 days after injury. Western blot analysis showed that levels of MAG protein decreased substantially 7 days after crush injury, which returned to 70% of the adult value by 21 days after injury. MAG mRNA and protein were undetectable by Northern and Western analysis, respectively, in the distal segment of the sciatic nerve 35 days after permanent transection. This infers distinct down-regulation of MAG gene expression after permanent transection of a peripheral nerve. These comparative studies of MAG transcripts and encoded protein may indicate regulation of MAG gene expression at the level of transcription, and possibly at the level of post-transcription in these experimental models of peripheral neuropathies.

Animals↗
PubMed1990

Point mutations impairing cell surface expression of the common beta subunit (CD18) in a patient with leukocyte adhesion molecule (Leu-CAM) deficiency.

The leukocyte adhesion molecules CD11a/CD18, CD11b/CD18, and CD11c/CD18 (Leu-CAM) are members of the integrin receptor family and mediate crucial adhesion-dependent functions in leukocytes. The molecular basis for their deficient cell surface expression was sought in a patient suffering from severe and recurrent bacterial infections. Previous studies revealed that impaired cell surface expression of Leu-CAM is secondary to heterogeneous structural defects in the common beta subunit (CD18). Cloning and sequencing of complementary DNA encoding for CD18 in this patient revealed two mutant alleles, each representing a point mutation in the coding region of CD18 and resulting in an amino acid substitution. Each mutant allele results in impaired CD18 expression on the cell surface membrane of transfected COS M6 cells. One substitution involves an arginine residue (Arg593----cysteine) that is conserved in the highly homologous fourth cysteine-rich repeats of other mammalian integrin subfamilies. The other substitution involves a lysine residue (Lys196----threonine) located within another highly conserved region in integrins. These data identify crucial residues and regions necessary for normal cell surface expression of CD18 and possibly other integrin beta subunits and define a molecular basis for impaired cell surface expression of CD18 in this patient.

Amino Acid Sequence↗
PubMed1990

Brain abscess: with special reference to infection by pseudomonas.

Eighty cases of brain abscess treated in the University Hospital, BHU, Varanasi, India have been reviewed. Chronic suppurative otitis media was the commonest cause, followed by compound injuries. The overall mortality was 15%. In seven cases the causative organism was pseudomonas, resistant to most antibiotics. Prior to the availability of CT the mortality was 23.3%; after the routine use of CT for diagnosis the mortality fell to 10%. A high mortality (57%) was observed in patients who had pseudomonas. The best results were in patients who had been managed by excision of the abscess capsule.

Adolescent↗
PubMed1990

The effect of dopamine D1 and D2 receptor agonists on inositol phosphate turnover in rat striatal slices.

There is a lot of controversy in the literature about the role of dopamine D1 and D2 receptor stimulation on the turnover of phosphoinositols, and phosphoinositols are one of the important second messenger. In order to resolve this controversy, the effect of dopamine receptor stimulation on turnover of phosphoinositols was studied by estimation of the accumulation of individual labelled inositols in rat striatal slices which were prelabelled with [3H]myoinositol. Incubation of the prelabelled striatal slices with 1 microM of quinpirole, D2 specific agonist or with 1 microM of SKF-38393, D1 specific agonist, did not affect the accumulation of basal level of either inositol monophosphate, or inositol biphosphate, or inositol triphosphate. In addition, in conclusion of D1 specific antagonist cis-flupentixol or D2 specific antagonist sulpiride did not affect the basal levels of inositol phosphates. The activity of enzyme phospholipase-C which produces these inositol phosphates was also measured in rat striatal membrane. Incubation of rat striatal membrane with either agonist quinpirole or SKF-38393 did not change the basal level of phospholipase C. Our data thus indicate that occupation of dopamine receptors did not affect the inositol phosphate system in rat striatum.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1990

Precipitation test--a rapid method for diagnosis of tuberculous meningitis.

Precipitation test (modified Lavinson's test) was conducted in 125 cases of meningitis. Of these, 50 cases (proved cases of tuberculous meningitis) who served as positive controls showed positive response for the precipitation test in 96% and in 25 cases of negative control group (cases of meningitis other than TBM), it showed only 4% positivity. The remaining 50 cases of TBM where the cytological and biochemical findings were not in correlation with clinical diagnosis of TBM, showed 92% positivity for early diagnosis of TBM.

Benzenesulfonates↗
PubMed1990

Inadequacy of diagnosis related group (DRG) reimbursements for limb salvage lower extremity arterial reconstructions. Ad hoc committee of the Joint Council of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery.

Prospective cost and reimbursement data were collected from 10 centers in various parts of the United States on 566 patients undergoing lower extremity arterial reconstructions for limb salvage and nonlimb salvage indications. Information for each patient was available on indication and type of procedure, length of stay, the type of hospital insurance, and hospital costs/charges. Diagnosis related group payments from each center were used to determine net gain or loss for each patient. Patients were classified as having claudication or critical ischemia (limb salvage). Reimbursements matched costs/charges for the claudication group; overall mean loss in this group was only $915 per patient. However, all centers had important losses in the limb salvage group. Reimbursements averaged 60% of costs/charges, with a mean loss of $8158 per patient and an overall loss for all 10 centers of $3,653,918. An effort to remedy this inequity is progressing via a dialogue between representatives of the Society for Vascular Surgery, the North American Chapter of the International Society for Cardiovascular Surgery, and the federal government.

Arteriosclerosis↗
PubMed1990

Relevance of immuno-contraceptive vaccines for population control. I. Hormonal immunocontraception.

Human chorionic gonadotropin--subunit beta (beta-hCG) has been so far most extensively studied antigen for immuno-contraceptive properties. Studies of vaccination of non-human primates has been so far controversially reported since some antisera obtained from baboons immunized with beta-hCG had shown cross-reactivity to other tissues. Despite these problems and concerns about the complete safety of this first generation vaccine, a decision has been made to proceed with a limited clinical trials with this vaccine. Results from these trials are encouraging and indicate that contraceptive antibody titers can be achieved with permissible adjuvants. Neutralization of LH and/or FSH by circulating antibodies may impede their action and interfere with the maturation of gametes. Gonadotropin releasing hormone can be also a suitable target for immunological attack.

Chorionic Gonadotropin↗
PubMed1990

A modified method for management of prosthetic graft infections involving an anastomosis to the common femoral artery.

In the last 10 years we have treated 28 patients with 33 groin infections involving a common femoral artery anastomosis of prosthetic arterial grafts (2 aortic Dacron grafts, 31 peripheral polytetrafluoroethylene grafts). Management included complete graft preservation for patent infected grafts (11 cases), subtotal excision of occluded infected grafts leaving an oversewn 2 to 3 mm graft remnant attached to a patent artery critical for limb survival (16 cases), and total graft excision with arterial oversewing or ligation for anastomotic bleeding (6 cases). Essential treatment adjuncts included (1) radical operative wound debridement, and (2) secondary revascularization by means of bypasses tunneled via lateral uninfected routes, and unusual approaches to uninvolved patent outflow arteries (i.e., the distal superficial or deep femoral or popliteal arteries) after isolation of the infected wound. Follow-up averaged 3 years (1 to 10 years). This plan of treatment resulted in an 11% (3/28) hospital mortality and an amputation rate of 13% (4/30 threatened limbs). Of the 25 survivors with 30 infected groin grafts, 87% (26) of the wounds healed uneventfully by secondary intention within 1 to 8 weeks (mean, 4 weeks) and have remained healed. One infected groin wound did not heal and required delayed total graft excision. Three patients had late anastomotic disruption with hemorrhage at 8 months, 2 years, and 4 years after initial treatment. This selected use of complete or partial graft preservation and other essential treatment adjuncts are proposed as a safer, easier method for managing infected prosthetic arterial grafts in the groin.

Adult↗