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Biomedical subjects

S Reddy

Publications and source records attributed to S Reddy.

At least 217 records · Page 12Linked to original sources
PubMed1991

Pre-treatment prognostic factors in stage III non-small cell lung cancer patients receiving combined modality treatment.

Approximately one-third of non-small cell lung cancer (NSCLC) patients present with locally advanced disease. Increasing numbers of clinical trials are being conducted in this group of patients and recently a new international staging system has been introduced, resulting in the sub-division of Stage III into IIIa (potentially operable disease) and IIIb (inoperable disease). Kaplan-Meier survival analyses and Cox regression analyses were used to analyze data from 129 Stage III NSCLC patients who had been treated on two consecutive Phase II trials testing combined modality treatment. The pretreatment characteristics of these patients were: median age--59 years, males/females--87/42, caucasian/non-caucasian--111/18, squamous cell or adenocarcinoma/large cell carcinoma--57/72, previous weight loss less than or equal to 5%/greater than 5%-76/46, previous history of cardiorespiratory disease--no/yes--91/36, performance status (PS) 0-1/2-3--102/27, Stage III, 2 groups--IIIa/IIIb--83/46, Stage III, 3 groups--IIIa T3 N0/IIIa N2/IIIb--41/41/47, surgical eligibility--eligible/ineligible--83/46. Kaplan-Meier statistics revealed significantly longer survival for PS 0-1 versus 2-3 (p = .001), for eligible versus ineligible for surgery (p = .003), for Stage-IIIa versus IIIb (p = .004), and for Stage-IIIa T3N0 versus IIIa N2 versus IIIb (p = .004). The best model developed from Cox regression analyses included stage (IIIa T3 N0 vs IIIa N2 vs IIIb), PS, and sex. These observations appear to have implications for clinical research in Stage III NSCLC.

Adenocarcinoma↗
PubMed1991

Results of radiotherapeutic management of primary carcinoma of the vagina.

Forty-five previously untreated patients with primary carcinoma of the vagina were treated with curative radiotherapy from 1965 through 1985. All patients were staged according to the FIGO system. One patient was classified as Stage 0, 15 as Stage I, 22 as Stage II, 6 as Stage III, and 1 as Stage IV. Treatment consisted of intracavitary irradiation alone in Stage 0 patients. Stage I patients received intracavitary/interstitial irradiation alone or in combination with external irradiation and an implant when feasible. When treated with an implant only, the total tumor dose delivered was between 65-70 Gy. External irradiation consisted of delivering a dose of 45-50 Gy over a period of 4 1/2-5 weeks to the whole pelvis to treat the regional lymph nodes. An additional dose of 20-25 Gy was delivered to the site of original involvement using an implant when feasible. If not technically feasible, as in advanced stages, the patient was treated with additional external irradiation to a total dose of 65-70 Gy by a shrinking field technique. All patients except one were followed either until death or for a minimum of 2 years. The actuarial 5-year survival rates were 100% for Stage 0, 78% for Stage I, and 71% for Stage II patients. None of the patients with Stage III or IV disease survived. Of the patients who recurred, all but two did so within 16 months after diagnosis. Pelvic recurrence as the first site of recurrence occurred in 86% of the patients who recurred. Distant recurrence as a component occurred in 20% of all failures. Complications as a consequence of therapy occurred in 18% of the patients. Vaginal necrosis that healed with conservative treatment was seen in four patients and the other four patients had rectal complications of varying severity. Thus, curative radiotherapy is an effective method of treatment, with acceptable morbidity, in patients with early stage primary carcinoma of the vagina.

Adult↗
PubMed1991

Gallstone pancreatitis: combined endoscopic and laparoscopic approaches.

Of 11 patients with gallstone pancreatitis, 10 underwent preoperative ERCP. Calculi were removed from the common duct in two patients. All patients underwent laparoscopic cholecystectomy, with normal rapid convalescence. The eleventh patient is recovering from pancreatitis with the bile duct accessed percutaneously. A combined endoscopic and laparoscopic approach to gallstone pancreatitis is safe and was associated with minimal risk in this small series.

Adult↗
PubMed1991

Insulin attenuation of vasoconstrictor responses to phenylephrine in Zucker lean and obese rats.

Recent data from this laboratory indicate that insulin resistant obese Zucker rats exhibit hypertension associated with exaggerated in vitro vascular reactivity to phenylephrine, serotonin, and KCl, and we have found insulin to attenuate vascular reactivity responses to these agonists. Accordingly, in the present study we evaluated the possibility that exaggerated vascular reactivity responses in obese Zucker rats may result from insulin resistance and a consequent failure of insulin to attenuate vasoactive responses. Thoracic aortae were isolated from male 16 week old lean and obese Zucker rats, and replicate helical strips from each animal were suspended in a muscle bath under a resting tension of 1.4 g in the presence or absence of insulin (0.1 mU/mL) for 1 h. The insulin was then washed out, and vascular reactivity responses to phenylephrine were determined. The obese rats exhibited greater reactivity to phenylephrine (ED50:1.10 +/- 90 X 10(-8) v 7.57 +/- 0.88 X 10(-10) mol/L in lean and obese rats, respectively, P less than .025). Insulin caused a significant attenuation of the contractile response in both the lean and obese aortae. However, lean rats exhibited a markedly greater attenuation than the obese rats (46.0 +/- 17.0 v 17.8 +/- 7.5% attenuation in the lean and obese rats, respectively, P less than .01). These data suggest that increased vascular reactivity responses in obese Zucker rats may result from their insulin resistant state and, consequently, a diminished ability of insulin to attenuate vasoconstrictor responses.

Animals↗
PubMed1991

Retrovirus promoter-trap vector to induce lacZ gene fusions in mammalian cells.

A retrovirus promoter-trap vector (U3LacZ) has been developed in which Escherichia coli lacZ coding sequences were inserted into the 3' long terminal repeat (LTR) of an enhancerless Moloney murine leukemia virus. The U3LacZ virus contains the longest reported LTR (3.4 kbp); nevertheless, lacZ sequences did not interfere with the ability of the virus to transduce a neomycin resistance gene expressed from an internal promoter. Duplication of the LTR placed lacZ sequences in the 5' LTR just 30 nucleotides from the flanking cellular DNA. Approximately 0.4% of integrated proviruses expressed beta-galactosidase as judged by 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) staining, and individual clones expressing lacZ were isolated by fluorescence-activated cell sorting. In all clones examined, beta-galactosidase expression resulted from the fusion of lacZ sequences to transcriptional promoters located in the flanking cellular DNA. Furthermore, by differential sorting of neomycin-resistant cell populations, clones were isolated in which lacZ expression was induced and repressed in growth-arrested and log phase cells, respectively.

Animals↗
PubMed1991

Transfer of Na transport inhibition in proximal tubules from saline volume-expanded to nonexpanded rats.

In dual micropuncture experiments the shrinking drop technique was used to measure volume flux with artificial tubular fluid (AF) alternating with harvested tubular fluid (HTF) during saline volume-expanded (VE) and nonexpanded (NE) periods. In VE rats, volume flux (Jv) (nl.mm-1.min-1) with AF was 1.78 +/- 0.08 (means +/- SE) during NE and was reduced to 1.39 +/- 0.09 (P = 0.01) during subsequent VE, whereas with randomly alternating HTF during VE it was 1.07 +/- 0.08 (P less than 0.0001 and less than 0.03, respectively). Jv with HTF from NE rats tested in the VE rats was 1.20 +/- 0.06, which is significantly higher than that measured with their own HTF (Wilcoxon rank, P = 0.05). In NE rats Jv was 1.65 +/- 0.10 and 1.69 +/- 0.10 with AF and HTF and was 1.28 +/- 0.07 (P less than 0.001 from both) with HTF obtained from VE rats. Elemental analysis of reaspirated tubular fluids showed no significant differences in Na or Cl concentrations among any of the fluids. It is concluded that during VE, a transferable Na transport inhibitor appears in proximal tubular fluid, which, together with a changed proximal tubular epithelium, possibly due to physical forces, accounts for proximal tubular Na transport inhibition during VE.

Animals↗
PubMed1991

Differential effects of angiotensin II and noradrenaline on tubular rejection of sodium produced by ANP in rats.

The effect of Atrial Natriuretic Peptide (ANP) on renal tubular sodium handling (FENa) in the presence of converting enzyme inhibition (CEI), the AII antagonist Saralasin (SAR), noradrenaline (NA) and angiotensin II (AII) infusions was investigated. FENa and increases in FENa produced by ANP were significantly lower with CEI (p less than 0.03 and 0.0001) or SAR (p less than 0.02 and 0.02) against control (Vehicle + ANP). Mean arterial pressures (MAP) were also reduced. Returning MAP to 107 +/- 2 mmHg with NA (+CEI+ANP), did not change FENa (1.22% +/- 0.16 to 1.25% +/- 0.18, p greater than 0.66) whereas without CEI but with ANP (MAP 113 +/- 2 mmHg) FENa was significantly increased by NA (2.34% +/- 0.36, p less than 0.02). With AII+CEI+ANP, MAP was restored to 110 +/- 5 mmHg, and FENa was highly significantly increased (0.99% +/- 0.20 to 3.04% +/- 0.39, p less than 0.0003) in excess of that expected due to pressure effects alone. It is concluded the additional effect of AII on FENa (3.04 versus 1.25% with NA) at equivalent perfusion pressures are due to a separate additive phenomenon of AII and ANP both causing tubular rejection of Na.

Angiotensin II↗
PubMed1990

Combined modality therapy for locally advanced non-small cell lung carcinoma.

Multi-modality treatment consisting of cisplatin, VP-16, and 5-fluorouracil chemotherapy given concomitantly with external beam radiation was used to treat 64 patients with locally advanced Stage III non-small cell lung carcinoma. This regimen was used in a preoperative fashion for four cycles in patients considered surgically resectable and with curative intent for six cycles in the remainder of patients. The clinical response rate for the entire group was 84% and the overall local control rate was 74%. The median survival was 13 months with a median follow-up for live patients of 19 months. The actuarial 3-year survival and disease-free survival rates were 30% and 23%, respectively. Histologic complete response was 39% and appeared to predict for survival. The 3-year actuarial survival and disease-free survival rates for 23 resected patients were 69% and 45%, respectively, with the complete histologic responders having a disease-free survival of 78%. The pattern of first recurrence did not appear to differ by histology or presence of lymph nodes in this subset of patients. The actuarial 3-year survival and disease-free survival rates for inoperable patients receiving six cycles of treatment were 18% and 23%, respectively. The local control was 67% with the majority of these patients having Stage IIIB disease. The Mountain International staging system appeared to predict for operability, local recurrence, and survival. This concomitant treatment regimen is feasible, with the major toxicities being leukopenia, nausea, and vomiting.

Adult↗
PubMed1990

Structure of the human smooth muscle alpha-actin gene. Analysis of a cDNA and 5' upstream region.

The structures of a cDNA and the 5' upstream region of the human smooth muscle alpha-actin gene have been characterized. Transcriptional start sites and the non-coding first exon were mapped by primer extension analysis and by comparing cDNA and genomic sequences. The deduced human smooth muscle alpha-actin protein sequence is identical to the corresponding bovine protein sequence, and thus confirms that the previously determined human genomic sequence contained a mutation at codon 312. Human smooth muscle cells express only a single, 1.4-kilobase smooth muscle alpha-actin transcript. 5' Noncoding sequences that have the greatest similarity to the chicken gene are located in five noncontiguous segments, extending from approximately 250 base pairs upstream of the cap site through the first exon. Conserved sequences encompass a region required for expression and tissue-specific regulation of chicken smooth muscle alpha-actin and therefore are probably also important for expression of the human gene.

Actins↗
PubMed1990

Familial adult T-cell leukemia/lymphoma.

Clinical and laboratory data are described for two siblings who both developed adult T-cell leukemia/lymphoma resulting from infection by human T lymphotropic virus type I (HTLV-I). These findings suggest that genetic factors or virus-specific factors may determine which HTLV-I-infected individuals will develop leukemia.

Adult↗
PubMed1990

Analysis of human chromosome 21: correlation of physical and cytogenetic maps; gene and CpG island distributions.

Human chromosome 21 has been analyzed by pulsed-field gel electrophoresis using somatic cell hybrids containing limited regions of the chromosome and greater than 60 unique sequence probes. Thirty-three independent NotI fragments have been identified, totalling 43 million bp. This must account for essentially the entire long arm, and therefore gaps remaining in the map must be small. The extent of the pulsed-field map has allowed the direct correlation of the physical map with the cytogenetic map: translocation breakpoints can be unambiguously positioned along the long arm and the distances between them measured in base pairs. Three breakpoints have been identified, providing physical confirmation of cytogenetic landmarks. Information on sequence organization has been obtained: (i) 60% of the unique sequence probes are located within 11 physical linkage groups which can be contained in only 20% of the long arm; (ii) 9/21 genes are clustered within 4%; (iii) translocation breakpoints appear to occur within CpG island regions, making their identification difficult by pulsed-field techniques. This analysis contributes to the human genome mapping effort, and provides information to guide the rapid investigation of the biology of chromosome 21.

Base Composition↗
PubMed1990

Treatment of 29 patients with bulky squamous cell carcinoma of the cervix with simultaneous cisplatin, 5-fluorouracil, and split-course hyperfractionated radiation therapy.

Attempting to improve local disease control in bulky (greater than 8 cm) primary or recurrent pelvic tumors, 29 patients with squamous cell carcinoma of the cervix (stage II, 4; III, 10; IV, 6; recurrent, 9) were treated with concomitant chemotherapy and split-course hyperfractionated radiation therapy between April 1983 and August 1988. Cisplatin (CDDP) and 5-fluorouracil (5-FU) have been shown to be radiation enhancers; furthermore, CDDP, radiation therapy, and continuous-infusion 5-FU have elicited high local response rates in head and neck squamous cell carcinoma. A pilot study of cyclical week on/week off CDDP, continuous-infusion 5-FU, and hyperfractionated radiation therapy was developed. Radiation was administered at 116 cGy twice daily, Days 1-5, every other week for a median dose of 4600 cGy to a pelvic field, with paraaortic extension if indicated. Concomitant chemotherapy included CDDP 60 mg/m2 IV Day 1 and 5-FU 600 mg/m2 IV continuous infusion for 96 hr following CDDP infusion. Patients received a median of four cycles of combined treatment, and intracavitary or interstitial brachytherapy followed in 21 patients. Local pelvic response was achieved in 29 of 29 (100%): complete response (CR) in 19 of 29 (66%), partial response (PR) in 10 of 29 (34%). Among CR patients 10 of 19 (53%) were without evidence of disease at a mean follow-up of 29 (range 12-76) months. Five-year actuarial disease-free survival among complete responders was 65%. Of the 10 CR patients 2 failed in the pelvis, for a local control rate of 17/19 (89%). Chemotherapy-related and acute radiation morbidity was minimal but 2 patients required surgical correction of radiation injury. Aggressive combination of split-course hyperfractionated radiation therapy with radiation enhancers resulted in promising local control of bulky pelvic tumor, with an acceptable complication rate, in this otherwise very poor prognostic group of patients.

Adult↗
PubMed1990

Preoperative radiation therapy in regionally localized stage III non-small cell lung carcinoma: long-term results and patterns of failure.

Seventy-four patients from January 1975 through December 1982, with clinical Stage III Mo non-small cell carcinoma of the lung were treated at our Medical Center with a course of pre-operative radiation therapy to be followed by surgical resection. Radiation therapy consisted of delivering a total dose of 40 Gy with 200 cGy per fraction over a period of 4 weeks to the primary tumor in the lung and the regional lymph nodal areas. Surgical resection was attempted 4 weeks later. Fifty-eight percent of the patients had squamous cell carcinoma whereas the remaining had other histologies like adenocarcinoma, large cell carcinoma, or a combination thereof. All the patients except two were followed up to a minimum of 5 years or until death. Sixty-four patients (82%) had T3 tumors whereas mediastinal nodal involvement was found in 41 patients (55%). Fifteen patients (20%) did not have the operation because of tumor progression, patient's refusal or death. All but two surgically treated patients had tumor resection. Of these 19% had histologically negative specimens, 9 patients (16%) had microscopic disease only, and 37 patients had gross residual disease at the time of surgery. The actuarial 5-year survival and recurrence-free survival rates for the entire group were 20% and 24%, respectively. Patients with a pathologic response had an actuarial recurrence-free survival rate of 53% at 5 years whereas only 17% of those with gross residual disease at surgery had remained recurrence-free at 5 years. One-half of the patients with clinically uninvolved nodes were living recurrence-free at 5 years whereas only 20% of the patients with N2 disease did so. The patterns of failure according to the histology and stage of the disease will be presented.

Adenocarcinoma↗
PubMed1990

Isolation of cellular promoters by using a retrovirus promoter trap.

A retrovirus vector has been used to isolate transcriptional promoters from mammalian cells. The virus contains a selectable gene encoding histidinol dehydrogenase (his) in the U3 region of the 3' long terminal repeat (LTR). When the virus is passaged, duplication of LTRs places his sequences just 30 nucleotides from the adjacent cellular DNA. As a result, selection for histidinol resistance generates cell clones in which his is expressed on transcripts initiating in the flanking cellular DNA. Upstream cellular sequences, cloned after amplification by polymerase chain reaction, hybridized to RNA from uninfected cells, indicating that the adjacent promoters were transcriptionally active prior to virus integration. Two cloned transcribed flanking sequences also contained highly active transcriptional promoters, as estimated by their ability to activate expression of a linked reporter gene. Thus, U3His vectors provide a rapid and efficient means to isolate promoters active in different cell types. Moreover, by selecting for cell clones containing proviruses integrated in expressed genes, the virus may make an effective insertional mutagen.

Base Sequence↗