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Biomedical subjects

S Raina

Publications and source records attributed to S Raina.

At least 73 records · Page 4Linked to original sources
PubMed1984

Scheduling of combination chemotherapy for a murine melanoma, with the subrenal capsular assay.

The effect of varying schedules for administration of two drugs, dimethyl triazeno imidazole carboxamide (DTIC) and methylcyclohexyl chloroethyl nitrosourea (MeCCNU), was studied using the Harding-Passey Mouse melanoma in the subrenal capsular assay. The results of the assay indicate that the responses of the tumor varied depending on the schedule of administration. The best response, with a mean decrease in dimensions of 3.0 ocular micrometer units (+/- 1.12 SD), was noted with administration of DTIC on day 1 after tumor implantation, followed by MeCCNU on day 2. These results are similar to previously reported data in CD2F1 mice bearing intraperitoneal Harding-Passey melanoma and suggest that the subrenal capsular assay may be of use in determining the best combinations and schedules of administration for treatment of tumors.

Animals↗
PubMed1984

Multimodality preoperative treatment for advanced cancer of the head and neck.

Neoadjuvant induction chemotherapy with cisplatin, methotrexate, and bleomycin appears to improve the results of treatment of advanced stage IV head and neck cancer, compared with results in historical control subjects. Patients treated with induction chemotherapy and radiation therapy had a 29 percent overall survival rate at 3 years, which represents approximately a twofold improvement in the survival rate. Patients who were treated with chemotherapy and radiation therapy followed by surgery had more than a threefold increase in the survival rate (49 percent at 3 years), compared with historical data from our institution and elsewhere for such patients [9-11]. Distant metastases developed in 25 percent of the patients, and it thus appears that long-term, effective consolidation and maintenance chemotherapy [12,13] need to be developed for patients who receive combination therapy before surgery for head and neck cancer.

Actuarial Analysis↗
PubMed1983

Current attitudes in the management of thyroid cancer.

The opportunity to assess the current attitudes of surgeons in the management of thyroid cancer was afforded by the responses to a questionnaire that was part of a "Questionnaire Course." The majority of the 72 respondents have a conservative surgical approach to thyroid cancer, find frozen section useful, recommend total thyroidectomy for medullary cancer, seldom or never split the sternum in performing thyroidectomy, and recommend visualization of the recurrent laryngeal nerves and the parathyroids. Opinions however, are divided on several other issues. Forty-two per cent (versus 34%) request ultrasound before removal of a "cold nodule." For follicular carcinoma, 44 per cent perform lobectomy with isthmustectomy, 29 per cent perform total ipsilateral lobectomy and subtotal contralateral lobectomy, and 23 per cent perform total thyroidectomy. Following lobectomy for follicular carcinoma, recommended treatments are radioactive iodine (25%), thyroid suppression (21%), and total thyroidectomy (48%). For anaplastic cancer, 44 per cent perform total thyroidectomy and 40 per cent perform radiation therapy. Histologically positive nodes are managed by modified radical neck dissection (61%) or by "berry picking" (23%). It is concluded that despite agreement on several therapeutic approaches for thyroid cancer, certain controversial issues remain unresolved.

Attitude of Health Personnel↗
PubMed1982

Severe pelvic infection from Chlamydia trachomatis after cesarean section.

A severe pelvic infection developed in a 17-year-old primigravida after a cesarean section. Multiple antibiotics were administered for presumed mixed aerobic and anaerobic infections, without improvement. Subsequently, total hysterectomy and bilateral salpingo-oophorectomy were performed. Despite negative standard cultures, her condition continued to deteriorate and she required two more exploratory laparotomies for suspected intra-abdominal abscesses. Chlamydia trachomatis and, subsequently, Candida albicans were recovered from cultures of peritoneal fluid obtained after the third operation. Serological tests confirmed the presence of acute chlamydial infection. Marked clinical improvement occurred after doxycycline hyclate administration. Although genitourinary and acute pelvic inflammatory diseases due to chlamydiae have been reported previously, no case of severe pelvic infection due to this agent after cesarean section had been described, to our knowledge. Specimens should be studied specifically for chlamydiae when standard cultures demonstrate no pathogens in women suffering from documented pelvic infection.

Abdomen↗
PubMed1982

Combined therapy in advanced squamous cell carcinoma of the head and neck.

The charts of 102 patients with stage IV squamous cell carcinoma of the head and neck, seen at the East Orange Veterans Administration Hospital between 1975 and 1979, were reviewed. Ninety-one of these patients were submitted to a protocol of high-dose preoperative radiotherapy, followed by surgery. Five-year actuarial survival in patients completing the protocol was 31.6 per cent. All patients who completed radiotherapy and were eligible for surgery, but refusing operation, died of their disease within three years. Historical controls for stage IV head and neck cancer have five-year survival rates of 0-16 per cent, depending on site. A recent review of the literature shows stage IV lesions treated with surgery alone have a five-year survival rate of 6 per cent.

Adult↗
PubMed1981

Role of T-cells in the mechanism of reactivity of the microplate leukocyte adherence inhibition assay.

To characterize the role of mononuclear cells in the microplate leukocyte adherence inhibition assay, enriched populations of T-cells, B-cells, macrophages, and a nylon wool-adherent fraction consisting of B-cells and macrophages were prepared by a two-stage adherence procedure from spleen cells of normal C57BL/6J mice and mice bearing progressively growing murine colon adenocarcinoma 38 (MCA-38) tumors. These studies indicate that the reactive cell undergoing specific antigen-induced adherence inhibition was present in the macrophage fraction. This cell was programmed to undergo specific antigen-induced adherence inhibition by an MCA-38-sensitized B-cell. An enriched population of MCA-38-sensitized T-cells but not normal T-cells abolished the in vitro leukocyte adherence inhibition response of MCA-38-reactive cells. Pretreatment of the MCA-38-sensitized T-cell fraction with anti-Thy 1:2 serum and complement but not anti-immunoglobulin and complement or carbonyl iron to selectively deplete macrophages abolished the regulatory effect of the MCA-38-sensitized T-cell fraction. MCA-38-sensitized T-cells could prevent MCA-38-sensitized B-cells from programming normal macrophages in vitro but could not abolish the leukocyte adherence inhibition response of presensitized macrophages. Temporal studies of suppressor T-cell activity were performed throughout different phases of progressive tumor growth. Suppressor T-cell could be detected as early as 4 days post-MCA-38 tumor cell inoculation and persisted throughout MCA-38 progressive tumor growth. Titration studies of suppressor T-cells revealed the need for 4 times the number of MCA-38-sensitized T-cells from small tumor bearers (Day 4) in comparison to large tumor bearers (Day 20) to achieve the same degree of suppression. Thus, in the MCA-38 system, sensitized T-cells programming of normal macrophages. This negative regulatory influence increased in magnitude with the progressive growth of the MCA-38 tumor.

Adenocarcinoma↗
PubMed1980

Multiple perforations of colon after compressed air injury.

Multiple perforations of the colon after compressed air injury occurred. The initial perforation did not become manifest until five days after the injury. This was repaired at laparotomy and a proximal colostomy was performed. Ten days after the first operation, a second laparotomy showed a second larger tear at the level of the peritoneal reflection. After a Hartmann procedure, the patient did well and was discharged from the hospital. This case emphasizes the need for repeated exploratory surgery of the abdomen if the initial postoperative course is not uneventful since full-thickness perforation of the colon may be delayed in its presentation.

Accidents, Occupational↗
PubMed1978

Effects of reperfusion on the regional contraction of ischemic and nonischemic myocardium following partial coronary obstruction.

In 14 dogs the effects on regional tension (Walton-Brodie gauges) and length (mercury-in-silastic) following 50% reduction (52.9 +/- 2.1) in coronary flow for two hours and reperfusion afterwards for one hour were addressed. Within five minutes of partial coronary occlusion, ejection tension in the ischemic zone decreased to 36.3 +/- 7.2% (P less than 0.001) and total tension to 64.4 +/- 5.7% of control (P less than 0.001) while phasic segment length increased to 165.2 +/- 16.3% control. No further significant changes in regional tension or length were observed throughout the two hour period of partial occlusion. Ejection tension remained positive and segment length maintained systolic shortening during the ejection phase throughout the period of occlusion. Following reperfusion, ejection tension in the ischemic zone increased from 35.1 +/- 5.9 to 87.0 +/- 22.0% (P less than 0.05) and total tension increased from 56.6 +/- 5.4 to 70.2 +/- 7.2% (P less than 0.02) while segment length decreased from 149.3 +/- 6.5 to 105.7 +/- 5.7% (P less than 0.001) within five to 15 min of reperfusion. The improvement in both regional tension development and segment length shortening was maintained throughout the one hour period of reperfusion. No significant changes were seen in the nonischemic zone. The present experimental study suggests that partial coronary occlusion producing a 50% reduction in coronary blood flow results in regional contractile changes. These changes are reversible at least twice as long as those following complete occlusion.

Animals↗
PubMed1977

Contrasting effects of dopamine and isoproterenol in experimental myocardial infarction.

The comparative effects of dopamine and isoproterenol on local myocardial contraction and ischemic injury after coronary occlusion were evaluated in 10 dogs. Dopamine (2.5 to 5 mug/kg per min) and isoproterenol (0.125 to 0.25 mug/kg per min) were randomly infused for 20 minutes, and segmental tension (Walton-Brodie gauge) of central ischemic, border and nonischemic myocardial zones and epicardial electrograms (10 to 12 sites) were simultaneously recorded. After coronary occlusion, tension in border zones decreased to 73.5 +/- 6.4 percent (mean +/- standard error of the mean) and tension in central zones to 60.6 +/- 9.9 percent (P less than 0.001) of control level, whereas total S-T elevation (sigmaST) rose from 10.8 +/- 1.6 to 98.4 +/- 14.0 mv and average S-T elevation (ST) from 1.6 +/- 0.2 to 10.8 +/- 1.6 mv (P less than 0.001). Isoproterenol increased heart rate from 148.7 +/- 6.9 to 170.6 +/- 7.7 beats/min (P less than 0.010) and improved tension in the border zone to 110.5 +/- 8.5 percent (P less than 0.010) and improved tension in the border zone to 110.5 +/- 8.5 percent (P less than 0.005) and nonischemic zone to 128.4 +/- 6.7 percent (P less than 0.02). Tension in the central zone was unchanged. However, sigmaST increased from 98.4 +/- 14.0 to 126.9 +/- 14.7 mv (P less than 0.005) and ST from 10.8 +/- 1.6 to 14.2 +/- 1.6 mv (P less than 0.001). Dopamine did not change heart rate but increased tension in the border zone from 72.4 +/- 7.9 to 124.4 +/- 16.8 percent (P less than 0.001) and tension in the nonischemic zone from 86.0 +/- 10.0 to 133.3 +/- 10.0 percent (P less than 0.01). Tension in the central zone was unimproved. However, sigmaST and ST did not increase (sigmaST from 99.8 +/- 10.8 to 97.7 +/- 13.9 mv and ST from 11.1 +/- 1.3 to 10.8 +/- 1.5 mv). Atrial pacing was used to increase heart rate during infusion of dopamine to 180.0 +/- 7.6 beats/min but neither sigmaST nor ST increased. In summary, both dopamine and isoproterenol decrease contraction abnormalities in the border and nonischemic zones after after acute coronary occlusion. Although isoproterenol increases both heart rate and S-T segment elevation, dopamine does not adversely affect either variable.

Animals↗
PubMedDate not supplied

Complex phenotypes of null mutations in the htr genes, whose products are essential for Escherichia coli growth at elevated temperatures.

Transposon insertion, followed by screening, has allowed the identification of a set of genes, called htr, whose products are required for Escherichia coli growth at elevated temperatures. The htrB gene has been shown to map at 23.5 min on the E. coli genetic map. It codes for a very basic, hydrophobic, 35,000-Mr polypeptide, possessing a putative membrane-spanning domain. At the non-permissive temperature, htrB mutant bacteria stop dividing, followed by the formation of bulges and eventual lysis. The htrC gene maps at 90 min, is under sigma 32 regulation and codes for a 21, 130-Mr polypeptide. At 43 degrees C, htrC mutant bacteria gradually lyse, whereas at intermediate temperatures they filament extensively. Finally, the htrM gene maps at 81 min, is under sigma 32 regulation and codes for a 35,000-Mr polypeptide. The HtrM null phenotype included inability to grow above 42 degrees C, extreme mucoidness and sensitivity to bile salts, even at the permissive temperatures. The htrM gene is identical to the rfaD gene, whose product is required for the biosynthesis of the lipopolysaccharide precursor ADP-L-glycero-D-mannoheptose (Pegues et al., J. Bact., 1990, 172, 4652-4660).

Bacterial Proteins↗
PubMedDate not supplied

Direct Agrobacterium tumefaciens-mediated transformation of Hyoscyamus muticus hairy roots using green fluorescent protein.

Hyoscyamus muticus hairy root segments were infected with Agrobacterium tumefaciens ASE containing the binary vector pCGN1548 with a green fluorescent protein (GFP) reporter gene under the control of the CaMV 35S promoter. The roots were incubated on callus-inducing medium to generate transformed cells. Transformants were selected on medium containing 50 and 100 mg/L kanamycin and screened by visual inspection for GFP expression. Highly fluorescent cells were incubated on phytohormone-free medium for regeneration of the hairy root phenotype. This infection technique can be applied directly to existing hairy root cultures which have been previously characterized and selected for desirable physiological traits. These studies also indicate that GFP is not toxic to H. muticus plant tissue and that H. muticus hairy roots have minimal autofluorescence which allows for clear observation of GFP.

Cell Culture Techniques↗
PubMedDate not supplied

Isolation and characterization of a locus from Azospirillum brasilense Sp7 that complements the tumorigenic defect of Agrobacterium tumefaciens chvB mutant.

The chromosomal virulence gene chvB of Agrobacterium tumefaciens is required for pathogenesis. A DNA fragment from the chvB locus can hybridize to DNA from Azospirillum brasilense Sp7. This DNA fragment could restore the tumorigenic activity of the chvB mutant strain A. tumefaciens A1011 towards leaf disks of Nicotiana tabacum. An NH2-terminal open reading frame, 480 codons long, was most likely responsible for the restoration of the tumorigenic activity. The A. brasilense sequence showed good homology with the NH2-terminal region of the ndvB gene of Rhizobium meliloti.

Agrobacterium tumefaciens↗