Search PubMed⌕ Search

Biomedical subjects

P Patel

Publications and source records attributed to P Patel.

At least 235 records · Page 13Linked to original sources
PubMed1988

Inhibition by anti-inflammatory agents of contraction induced by epidermal growth factor-urogastrone in isolated longitudinal smooth muscle strips from guinea-pig stomach.

1. Epidermal growth factor-urogastrone (EGF-URO) caused a concentration-dependent contractile response of longitudinal muscle strips from the gastric body of the guinea-pig stomach. The contractile response to EGF-URO was monophasic, with tension returning rapidly to baseline. Desensitization was evident in that further addition of EGF-URO to the organ bath did not cause a second contraction. 2. Preincubation with indomethacin, ibuprofen, naproxen and aspirin markedly inhibited the contractions induced by EGF-URO with an order of potency (indomethacin greater than naproxen greater than ibuprofen greater than aspirin) that reflected the ability of these agents to inhibit cyclo-oxygenase. 3. The data indicate that prostanoids mediate the action of EGF-URO in the longitudinal muscle preparation. 4. Auranofin (0.5 to 50 microM), a chrysotherapeutic agent with antiproliferative properties used for treating rheumatoid arthritis, also markedly inhibited the EGF-URO response; however, other gold-containing compounds (aurothioglucose or gold sodium thiomalate at 30 to 100 microM) failed to cause significant inhibition. 5. Preincubation of preparations for 2 h with 1 microM hydrocortisone, prednisolone or dexamethasone caused an inhibition of EGF-URO-induced contraction of approximately 50%. However, steroids lacking either a 17 alpha-hydroxyl (corticosterone) or an 11 beta-hydroxyl (cortisone, deoxycorticosterone, prednisone) substituent did not inhibit the contraction caused by EGF-URO. For hydrocortisone, the inhibitory effect was half-maximal at 0.2 microM and was maximal at 1 microM. Cycloheximide (10 microM) blocked the inhibitory action of hydrocortisone and potentiated the contractile action of EGF-URO. 6. The ability of a variety of steroidal and non-steroidal anti-inflammatory agents to interfere with the action of EGF-URO in a smooth muscle preparation suggests that these agents may also inhibit the action of EGF-URO mediated by prostanoids in other target tissues. 7. The data also point to a potential role for EGF-URO in regulating gastric motility.

Animals↗
PubMed1988

Screening of monoclonal antibodies for hCG for affinity and specificity.

Using human chorionic gonadotropin (hCG) as a model polypeptide, we have developed a strategy that allows the direct screening of supernatant fluids from hybridomas for the presence of monoclonal antibodies of high affinity and predefined specificities. The assay evaluates the competition between 125I-labeled and unlabeled homologous or heterologous antigens in a solid-phase two-site immunoradiometric assay. This assay is fast and accurate, and is of general use provided the antigen of interest can be purified in nanomolar quantities. This strategy led to the isolation of nine new monoclonal antibodies for hCG, two of which could be used for elaborating a sensitive two-site immunoradiometric assay for this hormone.

Animals↗
PubMed1988

Contraction of guinea pig trachea by epidermal growth factor--urogastrone.

To evaluate further the action of epidermal growth factor - urogastrone (EGF-URO) in smooth muscle systems, we examined the effect of the peptide on guinea pig tracheal strips. The cumulative addition of EGF-URO to the organ bath resulted in a concentration-dependent tonic contraction without tachyphylaxis. The half-maximal contraction was obtained at 13 +/- 3 ng/mL EGF-URO (2 nM). The maximum contraction at 100 ng/mL approached 60% of that induced by 1 microM histamine. No significant difference in the EGF-URO-induced contraction was observed in the presence or absence of a functional epithelium. Preincubation with 1 microM indomethacin for 20 min abolished the action of EGF-URO. The contractile effect of EGF-URO was not affected by yohimbine, propranolol, atropine, tetrodotoxin, and esculetin. However, mepacrine caused inhibition by 37 +/- 7% (mean +/- SEM for n = 3). Verapamil (10 microM) inhibited the EGF-induced response by 62 +/- 5% (mean +/- SEM for n = 4); the response was also absent in Ca-free (1 mM EGTA) buffer. However, the response was restored after the readdition of calcium. Our results suggest that EGF-URO can modulate tracheal smooth muscle contractility via a cyclooxygenase product and raise the possibility that EGF-URO might play a role in controlling pulmonary smooth muscle tone in vivo.

Animals↗
PubMed1988

Financial risk, hospital cost, and complications and comorbidities (CCs) in non-CC stratified neurosurgical diagnostic related groups (DRGs).

The purpose of this study was to analyze hospital resource consumption in the nine neurosurgical DRGs not stratified by complicating condition (CCs) (i.e., those neurosurgical DRGs that give no additional payment for associated medical conditions or complications occurring in the hospital). We analyzed 148 Medicare patients in these non-CC stratified neurosurgical DRGs and found that patients with a greater number of CCs had higher hospital resource consumption, substantial financial risk under DRGs, and a poorer outcome than patients with no CCs. These data suggest that the current DRG classification scheme may be inequitable vis-à-vis the non-CC stratified neurosurgical DRGs at our hospital. Hospitals that treat significant numbers of these patients may face disincentives to care for them under prospective Medicare DRG reimbursement.

Blood Transfusion↗
PubMed1987

The integration host factor of Escherichia coli binds to bent DNA at the origin of replication of the plasmid pSC101.

The integration host factor (IHF) of Escherichia coli is necessary for maintenance of pSC101. The protein binds specifically to the replication origin of the plasmid, in the AT-rich region located immediately adjacent to the left, weak binding site for the plasmid-encoded initiator protein. DNAase I and OH- radical footprinting experiments showed that IHF protects 49 bp of the DNA at the origin region. Methylation protection analyses revealed that IHF contacts purine residues in both the major and minor grooves of the DNA. Electrophoretic analyses showed that IHF binds to bent DNA, and the protein binding further enhances the degree of DNA bending. Site-directed mutagenesis of three of the contact points not only abolished binding of the protein to the DNA but also inactivated the replication origin. Therefore, binding of IHF to the ori sequence most probably is necessary for initiation of plasmid replication.

Bacterial Proteins↗
PubMed1987

Postoperative neuroleptic malignant syndrome. A case report.

A case of postoperative neuroleptic malignant syndrome is presented. A healthy 23-year-old male underwent a shoulder repair under uneventful fentanyl, halothane, nitrous oxide and oxygen anaesthesia. He received droperidol 5 mg IV and metoclopramide 10 mg IV intraoperatively to prevent postoperative nausea. Postoperatively, the patient developed autonomic instability, fever and generalized muscle rigidity. His level of consciousness was depressed. These findings were consistent with the diagnosis of neuroleptic malignant syndrome. The supportive treatment of the patient included active cooling measures, muscle relaxation and mechanical ventilation. The ability of anti-dopaminergic agents, including metoclopramide and droperidol, to precipitate the neuroleptic malignant syndrome is discussed. Treatment of the neuroleptic malignant syndrome is briefly discussed.

Adult↗
PubMed1987

Use of intravenous methylprednisolone in acute idiopathic thrombocytopenic purpura.

Twenty newly diagnosed children with acute idiopathic thrombocytopenic purpura (ITP) with a platelet count (PC) of less than 20,000 were treated with intravenous methyl prednisolone (IVMP) 5 mg/kg/day in four divided doses until the platelet count increased to 50,000/mm3. They were then placed on oral prednisone at conventional doses for a total of three weeks of steroid therapy. The platelet counts increased by an average of 55,000/mm3 within 48 h of treatment. Within 72 h (day 3) of treatment all patients achieved a PC of greater than 20,000/mm3. By day 5, all 20 patients achieved a PC of greater than 50,000. IVMP is highly effective in rapidly raising the PC in acute ITP above the critical level of 20,000, thereby reducing the duration of risk for intracranial hemorrhage (ICH).

Adolescent↗
PubMed1987

Amiodarone-induced pulmonary toxicity mimicking metastatic lung disease.

A 65 year old man developed atrial arrhythmias secondary to a congestive cardiomyopathy which were resistant to quinidine and disopyramide. Amiodarone controlled the paroxysmal atrial tachycardia but 4 months after starting the drug he developed increasing dyspnoea and radiological changes highly suggestive of metastatic lung disease. Lung biopsy showed change of drug-induced pneumonitis and 4 months after stopping amiodarone his symptoms resolved and the chest X-ray had cleared. Amiodarone may cause pulmonary toxicity mimicking metastatic lung disease.

Aged↗
PubMed1986

Propranolol pharmacokinetics during the menstrual cycle.

The pharmacokinetics of propranolol during menstruation and in the mid menstrual cycle have been studied in nine young women taking a single 80 mg tablet on each occasion. There were wide between-individual differences in the serum concentration at any given time (4-5 fold at peak concentrations) but the serum concentration time curves within individuals showed only mild variations. The differences between the average pharmacokinetic parameter estimates for the group did not differ significantly between the two periods of study.

Adolescent↗
PubMed1986

Surgonomics: the cost dynamics of craniotomy.

Prospective payment systems using the diagnostic related group (DRG) mechanism are being phased in for Medicare inpatient hospital care. The purpose of this study was to examine a common neurosurgical procedure (001), craniotomy without trauma, and characterize the cost dynamics of this DRG. All patients (n = 50) treated in this DRG at the Long Island Jewish Medical Center during 1983 had their financial charges exclusive of physician fees examined. The findings were: (a) each hospital service category had wide charge variances around the mean; (b) emergency (ER) admissions were 200% more expensive than nonemergency (non-ER) admissions; (c) ER admissions seemed to have no greater severity of illness than non-ER admissions, but had a significantly different referral pattern (i.e., admission from the ER to a nonneurosurgical service with a subsequent neurosurgical referral); (d) this DRG when grouped into clinical "subproducts" (i.e., craniotomy for tumor, hematoma, hydrocephalus, aneurysm, benign cyst, and other) showed marked charge differences; and (e) the most expensive 25% of patients had five times higher charges than the least expensive 25% for both ER and non-ER admissions. This type of financial analysis may give surgeons a methodology with which to address the problems of cost containment in a more serious manner.

Adult↗
PubMed1985

Isolation and characterization of mutant strains of Escherichia coli altered in H2 metabolism.

A positive selection procedure is described for the isolation of hydrogenase-defective mutant strains of Escherichia coli. Mutant strains isolated by this procedure can be divided into two major classes. Class I mutants produced hydrogenase activity (determined by using a tritium-exchange assay) and formate hydrogenlyase activity but lacked the ability to reduce benzyl viologen or fumarate with H2 as the electron donor. Class II mutants failed to produce active hydrogenase and hydrogenase-dependent activities. All the mutant strains produced detectable levels of formate dehydrogenase-1 and -2 and fumarate reductase. The mutation in class I mutants mapped near 65 min of the E. coli chromosome, whereas the mutation in class II mutants mapped between srl and cys operons (58 and 59 min, respectively) in the genome. The class II Hyd mutants can be further subdivided into two groups (hydA and hydB) based on the cotransduction characteristics with cys and srl. These results indicate that there are two hyd operons and one hup operon in the E. coli chromosome. The two hyd operons are needed for the production of active hydrogenase, and all three are essential for hydrogen-dependent growth of the cell.

Bacteriophages↗