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Biomedical subjects

S Krishnasamy

Publications and source records attributed to S Krishnasamy.

26 records · Page 2Linked to original sources
PubMed1992

The impact on survival by adjuvant chemotherapy and radiation therapy in stage II non-small-cell lung cancer.

Forty-nine consecutive patients with pathologic Stage II non-small-cell lung cancer treated over a 15-year period were retrospectively reviewed. The treatment strategy evolved during the period of review. Early patients were treated with surgery alone (S); subsequent patients were treated with adjuvant radiation therapy (SR); and more recent patients were treated with postoperative chemotherapy and radiation therapy (SRC). Fifteen patients received S alone, 10 patients received SR, and 24 patients received SRC. The median survival time (MST) of all 49 patients was 20 months, and the estimated 5-year survival was 25%. The MST of patients in each of the three treatment arms was S-6 months; SR-19 months; and SRC-25 months. The majority of patients died from systemic relapses or second primary lung cancers. The addition of adjuvant therapy (SR, SRC) significantly improved the MST of patients compared to surgery alone (S). The overall survival of patients did not change between treatment arms.

Adult↗
PubMed1990

5-Fluorouracil with oral leucovorin and hydroxyurea and concomitant radiotherapy for stage III non-small cell lung cancer.

Twenty-three patients with regionally advanced non-small cell lung cancer (NSCLC) (Stage III) were treated with continuous infusion 5-fluorouracil (5-FU) augmented by high-dose oral leucovorin and hydroxyurea and concomitant radiotherapy. This chemoradiotherapy regimen was administered during 5 days of every other week for six cycles (total radiation dose, 6000 cGy). Three patients (13%) had stable disease, 13 patients (57%) had a partial response (PR), and 1 patient (4%) had a complete response (CR). The overall response rate was 61% (95% confidence interval, 41% to 81%). At a median follow-up time of 19 months, the median survival time for all 23 patients was 12 months. The median time to disease progression was 6 months. Twelve patients have had disease progression outside of the chest, and only 3 patients have had intrathoracic disease progression as the site of first failure. The toxicities of this regimen consisted of mild to moderate myelosuppression and moderate degree dermatitis and mucositis. It was concluded that concomitant chemoradiotherapy with this regimen results in high local activity at acceptable toxicity. However, the systemic activity of this regimen was low, resulting in a high distant recurrence rate and a median survival time that was not different from that achieved with standard therapy. Therefore, its use, as defined in this study, cannot be recommended.

Administration, Oral↗
PubMed1990

"Instant-mix" whole brain photon with neutron boost radiotherapy for malignant gliomas.

From July 1985 through March 1987, 44 consecutive patients with supratentorial, nonmetastatic anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) were treated with whole brain photon irradiation with concomitant neutron boost at the University of Chicago. All patients had biopsy proven disease and surgery ranged from biopsy to total gross excision. Whole brain photon radiation was given at 1.5 Gy per fraction, 5 days weekly for a total dose of 45 Gy in 6 weeks. Neutron boost radiation was prescribed to a target minimum dose that included the pre-surgical CT tumor volume plus 1 cm margin. Neutrons were administered 5-20 minutes prior to photon radiation twice weekly and a total dose of 5.2 Gyn gamma was administered over 6 weeks. Median follow-up was 36 months. The median survival was 40.3 months for anaplastic astrocytoma (10 patients) and 11 months for glioblastoma multiforme (34 patients) and 12 months for the overall group. Variables that predicted longer median survival included histology (AA vs. GBM), age (less than or equal to 39 years vs. older), and extent of surgery (total gross or partial excision vs. biopsy) whereas tumor size and Karnofsky performance status did not have a significant influence. The median survival of the anaplastic astrocytoma group was better than expected compared to the RTOG 80-07 study (a dose-finding study of similar design to this study) and historical data. Reasons for this are discussed.

Adult↗
PubMed1989

Treatment of carcinoma of the proximal esophagus.

Selection of therapy for carcinoma of the proximal esophagus is controversial. We reviewed our experience with 41 patients with carcinoma of the esophagus within 24 centimeters of the incisor teeth to address this issue. Thirty-seven patients had squamous cell carcinoma, three had adenocarcinoma and one patient had a mucoepidermoid carcinoma. Seventeen patients underwent surgical therapy, which consisted of a resection in 15, colonic bypass in one patient and extracorporeal bypass in one. Ten patients underwent postoperative radiation therapy. Radiation therapy was the primary treatment in 23 patients and chemotherapy alone in one patient. The three month mortality rate was similar for patients with tumor resection and for those receiving radiation therapy as the primary treatment. Median survival time for patients undergoing resection and adjuvant radiation therapy was 12 months and seven months for those receiving only irradiation. Statistical analyses were not performed because patients with radiation only had more advanced disease, invalidating comparison. In terms of palliation, ten of the patients who had radiation therapy could eat solid food, seven could only swallow liquids and six had persistent, complete obstruction. All 12 of the survivors who had a resection were able to eat solid food. Although the one month mortality rate is higher for those treated surgically than with radiation therapy, the three month mortality rates are similar. Surgical treatment provides better palliation and a reasonable survival time and is preferred for patients with resectable disease who are physiologically fit enough to undergo operation. A benefit of postoperative adjuvant radiation therapy is undefined but probably present.

Adenocarcinoma↗
PubMed1988

Heat shock response of the chloroplast genome in Vigna sinensis.

The light-dependent protein synthesis occurring in chloroplasts isolated from the leaves of 7-day-old Vigna sinensis responded to heat shock with the induction of a set of four heat shock proteins (HSPs). The synthesis of these four HSPs at the elevated temperature was transcriptionally regulated, and all of them were found to be thylakoid membrane-bound. The synthesis of these chloroplast-coded HSPs was also observed in etioplasts during protein synthesis at the elevated temperatures with the exogenously added ATP. The in vivo induction of these plastid-coded HSPs was observed only in the leaves subjected to gradual increase in temperature but not in leaves subjected to rapid heat shock. Further, the in vitro synthesis of these plastid-coded HSPs was seen only in chloroplasts isolated from the control or from leaves subjected to gradual increase in temperature and not in chloroplasts isolated from leaves subjected to rapid heat shock. Taken together these observations suggest that in V. sinensis, the plastid genome contains a definite heat shock response and the in vivo expression of this response corresponds to the gradual rise in temperature normally occurring under field conditions.

Chloroplasts↗
PubMedDate not supplied

Characterization of the radish mitochondrial orfB locus: possible relationship with male sterility in Ogura radish.

The orfB locus of the normal (fertile) and Ogura (male-sterile) radish mitochondrial genomes has been characterized in order to determine if this region, which has previously been correlated with cytoplasmic male sterility (CMS) in Brassica napus cybrids (Bonhomme et al. 1991; Temple et al. 1992), could also be involved in radish CMS. In normal radish, orfB is expressed as a 600-nucleotide (nt) transcript. In Ogura radish, orfB is present as the second gene of a 1200-nt transcript that also contains a 138-codon open reading frame (orf138). Sequences showing similarity to orf138 are present in normal radish, but are not expressed.

Amino Acid Sequence↗