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Biomedical subjects

S Krishnamurthy

Publications and source records attributed to S Krishnamurthy.

At least 55 records · Page 3Linked to original sources

Send severely head-injured children to a pediatric trauma center.

Between 1985 and 1988, a total of 1,320 head-injured children were seen by the neurosurgical service at the Children's Hospital in Washington, D.C. (CHOW). This included 1,095 minor injuries, 127 moderate injuries, and 98 severe injuries. Children brought from the scene of an accident were considered direct transports, whereas those taken to another hospital prior to transfer to CHOW were indirect. Of the children that suffered severe head injuries, 56 were admitted directly to the hospital and 42 indirectly. The indirect group had a higher percentage of children with lower coma scores and abused children. The trauma score was significantly higher in the direct group (9 vs. 7). The mortality rate for severe injuries referred directly from the scene of the accident was 26.8%, and the mortality rate for children referred indirectly was 50.0%. The higher number of abused children in the indirect group did not account for the increase in mortality rate (p = 0.021) in this group. This is the first study to show that children brought directly from the scene of an accident to a well-established pediatric trauma center have a significantly better chance of survival than children transported first to the nearest available hospital.

Adolescent↗

Post-cesarean section splenic rupture.

We report a case of splenic rupture after cesarean delivery for abruptio placentae. The diagnosis was not suspected until a laparotomy was performed. Diagnosis and management were complicated by disseminated intravascular coagulation and renal failure. The importance of early diagnosis and management modalities are discussed.

Abruptio Placentae↗

Enzymes for enhancing bioremediation of petroleum-contaminated soils: a brief review.

During the 1950s and 1960s, hundreds of thousands of underground storage tanks (and above-ground storage tanks) containing petroleum products and hazardous chemicals were installed. Many of these tanks either have been abandoned or have exceeded their useful lives and are leaking, thereby posing a serious threat to the nation's surface and groundwater supplies, as well as to public health. Cleaning up releases of petroleum hydrocarbons or other organic chemicals in the subsurface environment is a real-world problem. Biological treatment of hydrocarbon-contaminated soil is considered to be a relatively low-cost and safe technology; however, its potential for effectively treating recalcitrant wastes has not been fully explored. For millions of years, microorganisms such as bacteria, fungi, actinomycete, protozoa, and others have performed the function of recycling organic matter from which new plant life can grow. This paper examines the biological treatment technology for cleaning up petroleum product-contaminated soils, with special emphasis on microbial enzyme systems for enhancing the rate of biodegradation of petroleum hydrocarbons. Classifications and functions of enzymes, as well as the microbes, in degrading the organic contaminants are discussed. In addition, the weathering effect on biodegradation, types of hydrocarbon degraders, advantages associated with enzyme use, methods of enzyme extraction, and future research needs for development and evaluation of enzyme-assisted bioremediation are examined.

Bacteria↗

Pancreatic metaplasia in Barrett's esophagus. An immunohistochemical study.

While pancreatic metaplasia has been observed in gastric mucosa of patients with chronic gastritis, it has not been described in ectopic gastric mucosa. We have identified focal clusters of cells resembling pancreatic acinar cells (CPACs) in 11 of 350 biopsies of Barrett's mucosa from 120 patients with Barrett's esophagus enrolled in a clinical efficacy trial of omeprazole versus ranitidine for treatment of gastroesophageal reflux disease. Three additional cases from our surgical files were also studied. Immunoreactivity for trypsin and chymotrypsin was present in the CPACs of all 14 cases, while stains for alpha-amylase and lipase were each positive in 12 of 13. A few cells in the CPACs were also positive for chomogranins (12 of 13 cases), serotonin (seven of 13 cases), somatostatin (three of 12), gastrin (four of 11), and pancreatic polypeptide (two of 13). No staining was seen for insulin or glucagon. Ultrastructural studies performed in one case showed features of pancreatic exocrine and endocrine (PP-type) cells in cells within CPACs. These results collectively indicate that the CPACs are aggregates of true pancreatic acinar cells admixed with a few endocrine cells. This pancreatic parenchyma in Barrett's mucosa is most likely of metaplastic origin and could be derived from the transitional zone cells or from pluripotent stem cells in the esophageal mucosa or from metaplasia of mucus cells. While the development of pancreatic metaplasia in Barrett's esophagus appears to be unrelated to drug therapy, the clinical relevance of this distinctive histological finding needs further investigation.

Adolescent↗

The use of fabric softener in neurosurgical prosections.

Cadaver prosections are very important for understanding the anatomy of various neurosurgical approaches. Formaldehyde fixation is an often-used, time-tested method of preserving cadavers, but it makes dissecting difficult, as tissues are rendered very tough and rigid. The alternatives to formaldehyde fixation that are currently available to make the tissues soft and more life-like either are time-consuming or shorten the period of time for which cadavers can be stored. We examined the effect of fabric softener (methyl bis [tallow amido ethyl] 2-hydroxyethyl ammonium methyl sulfate) on formaldehyde-fixed brains to make them soft and life-like. The deformability was measured by using a Schiotz ocular tonometer. We found that the use of fabric softener makes the brain significantly softer (P < 0.005) when compared with a standard diluted formalin solution. We also used fabric softener in neurosurgical prosections and found that the brain can be made soft enough to be able to retract. In addition, it can be used to better demonstrate the planes of tissue cleavage, making it very useful in simulating a life-like situation. We conclude that the use of fabric softener is a simple, reversible, inexpensive technique of obtaining ideal tissue texture for dissection of embalmed cadavers to demonstrate neurosurgical approaches.

Brain↗

Lasers in neurosurgery.

Lasers have been used in neurosurgery for the past 25 years, undergoing modifications to suit the specific needs of this medical discipline. The present report reviews the current use of lasers in neurosurgical practice and examines the pros and cons of lasers in specific neurosurgical applications. In spite of their advantages, laser use is still not widespread in neurosurgery. One reason is the continued lack of complete control over real-time laser interactions with neural tissue. A greater acceptance and use of lasers by neurosurgeons will depend upon automated control over defined specific parameters for laser applications based upon the type of tissue, the desired effect on tissue, and application to the clinical situation without loss of precision and a lot of expense. This will require the integration of newer lasers, computers, robotics, stereotaxy, and concepts of minimally invasive surgery into the routine management of neurosurgical problems.

Brain↗

A computerised cancer registry data and validation system in India--its implications for developing countries.

The cancer registration system in India, and an appropriate computer program to validate the cancer patient data it generates, are described, with the resource inputs, and outputs of research, training, awareness creation and cancer control, in the context of local health care systems. Computer packages already available mostly address the type of data obtainable from western health care systems. The same factors that limit health care systems in India, and probably most other developing countries--inadequate health care facilities, skeletal medical records systems, meagre and unavailable vital statistics, few trained staff, funding and computer facilities--also limit the data sent to the National Cancer Registry Programme. The computer program we developed checks for the reliability and validity of various cancer diagnostic, spread, therapeutic and outcome variables. The program is in HIBASIC for a CPM operating system with a minimum of 64 kB memory, adaptable to MS-DOS systems, population-based cancer registry data, and perhaps to other types of chronic disease registries, with relevant modifications. Since reliable cancer registry data are needed for effective cancer control measures, this program may help in such efforts in developing countries.

Computers↗

The descriptive epidemiology and trends in incidence of nonocular malignant melanoma in Bombay and India.

Nonocular malignant melanoma is a rare but lethal disease increasing in incidence and mortality in western countries with improved survival if diagnosed and treated early. This study reports its epidemiology from cancer registry data in six different parts of India; its anatomic distribution and trends in Bombay from 1964 to 1984. Age-adjusted incidence in Bombay patients shows no increase from 1964 to 1984 unlike in white caucasians. Males exceed females in patients 45 years or older unlike whites, but are equalled or exceeded by females in those less than 45 years. The sole of foot and internal mucous membranes are its major anatomic sites in Indians as in negroid blacks. This cancer in Indians resembles that in blacks and nonwhites in affecting less pigmented epithelia and skin. Susceptible melanosomes and ultraviolet light exposure may both be involved in its aetiopathogenesis.

Adult↗

Ultrastructural changes in mild gastroesophageal reflux disease: results of a pilot study.

Few studies have examined the ultrastructural changes in mild reflux esophagitis. Endoscopic esophageal biopsies were obtained from 10 patients with reflux symptoms and mild endoscopic esophagitis (grade 0:3 patients, grade I: 7 patients) and 9 patients with erosive esophagitis (grade II-IV), at least 5 cm above the Z line. The biopsies were evaluated by light and transmission electron microscopy. Ultrastructural changes were present in one patient with grade 0, 7 with grade I and 9 with grade II-IV esophagitis. Four of the 10 patients with grade 0-I esophagitis and 6 of 9 with grade II-IV esophagitis had light microscopic abnormalities. The ultrastructural abnormalities in patients with mild esophagitis were seen in the cell membrane, cytoplasmic organelles, desmosomes, and nuclei of all the three layers of esophageal mucosa and the basal lamina. Ultrastructural studies by transmission electron microscopy on endoscopic pinch biopsies may be a sensitive research tool to study the pathogenesis of mild reflux esophagitis.

Adult↗

Psammomatous carcinoid tumor of the duodenum.

We report a case of psammomatous calcification in a carcinoid tumor of the ampulla of Vater. Although the tumor was glandular, its neuroendocrine nature was proved using chromogranin immunostain.

Aged↗

Prognosis of operable squamous cell carcinoma of the esophagus. Relationship with clinicopathologic features and DNA ploidy.

BACKGROUND: Reports on the influence of various prognostic factors in carcinoma of the esophagus are conflicting. The prognostic value of a set of clinicopathologic factors and DNA ploidy were examined in 74 patients with surgically resected squamous cell carcinoma of the lower and middle third of the esophagus. METHODS: All patients had surgery performed in a single thoracic surgical unit at the Tata Memorial Hospital between January, 1984 and December, 1987. The clinicopathologic factors studied were (1) gross residual disease at operation; (2) morphology of the tumor; (3) depth of microscopic invasion; (4) lymph node involvement; (5) histologic grade; (6) vascular and lymphatic embolism; and (7) sex. DNA ploidy and S-phase fraction (SpF) were determined by flow cytometry on archival tissues extracted from paraffin blocks. Ploidy status could be determined successfully in all 74 tumors, whereas SpF could be assessed only in 25. RESULTS: Of the various prognostic factors examined with the Cox stepwise regression model, residual disease (P = 0.000), depth of invasion (P = 0.047), and lymph node status (P = 0.077) were found to be correlated with overall survival. CONCLUSIONS: DNA ploidy was not related to prognosis. The overall survival of this group of patients at 36 months was 28%, and median survival was 18 months.

Carcinoma, Squamous Cell↗

Chronic intestinal pseudo-obstruction in infants and children caused by diverse abnormalities of the myenteric plexus.

BACKGROUND: Chronic intestinal pseudo-obstruction is a motility disorder that leads to severe disability in infants and children. Our purpose was to study the myenteric plexus in infants and children with pseudo-obstruction METHODS: Using cross sections stained with H&E and frozen tangential sections of the myenteric plexus processed using Smith's silver technique, the myenteric plexus of the stomach, small intestine, and colon from 26 affected infants and children was analyzed quantitatively. RESULTS: Under H&E staining, there were decreased neuron scores of 34.1 +/- 7.4 and 25.3 +/- 7.1 in the jejunum and ileum (normal, 57.5 +/- 6.2 and 55.0 +/- 4; P = 0.005 for both). Using Smith's technique, the specimens had decreased argyrophilic neuron counts of 3.1 +/- 1.4, 3.6 +/- 1.1, 3.4 +/- 1.0, and 2.8 +/- 0.6 in the duodenum, jejunum, ileum, and colon, respectively (normal, 14.0 +/- 1, 14.8 +/- 1, 14.7 +/- 0.5, and 13.6 +/- 1.1; P < 0.0003). The abnormalities included (1) absence of myenteric plexus in 3 patients; (2) small numbers of neuronal structures present on H&E stains but the absence of the plexus on silver stains in 2; and (3) myenteric plexus present but decreased argyrophilic neurons and axons on silver stains in 18. The abnormalities would have been missed in 10 patients if H&E had been used alone, whereas Smith's technique identified the deficiency of argyrophilic neurons in all patients tested. CONCLUSIONS: Pseudo-obstruction in infants and children may be caused by diverse abnormalities of the myenteric plexus.

Abnormalities, Multiple↗

Gender differences and low birth weight with maternal smokeless tobacco use in pregnancy.

A preliminary study of maternal smokeless tobacco use, mostly oral applications of burnt tobacco or 'mishri', in pregnancy showed 65 of 178 singleton liveborns occurred to users and 113 to non-users in Bombay, India. Eighty-three newborns, 42 to maternal tobacco users and 41 to non-users were < 2.5 kg birth weight, i.e. low birth weight (LBW; odds ratio 3.2; confidence interval 1.5-6.9; P < 0.001). Stratifying by gender yielded odds ratios of 1.6 (P > 0.1, NS) for male and 6.96 (confidence interval 2.5-19.4, P < 0.0005), for female newborns compared to normal birthweight boys and girls, respectively. Male:female newborns were 80.6:100 in maternal tobacco users compared to 105.5:100 in non-users. Defining LBW as < 2.0 kg yielded an odds ratio of 5.4 (confidence interval 1.8-15.2, P < 0.005) in maternal tobacco users' offspring. For babies weighing 2-2.5 kg at birth it was 2.76 (confidence interval 1.4-5.5, P < 0.01). Maternal use of 'mishri' tobacco in pregnancy may be associated with (1) the offsprings' low birth weight, (2) low birth weights in girls more than in boys; (3) decreased male:female ratio in live newborns, and (4) low birth weight of < 2.0 kg more than of 2-2.5 kg. Studies are needed to substantiate these findings. Gender differences in outcome suggest the in utero effect of maternal smokeless tobacco use on male and female fetuses may differ.

Female↗

The effects of ventilator working pressure during pressure support ventilation.

The purpose of this study was to examine the consequences of altering ventilator working pressure on airway pressure and flow characteristics during pressure support ventilation (PSV). A ventilator (Siemens Servo 900C) and single lung simulator were used, and graphic read outs, in triplicate, were taken at a variety of combinations of PSV, working pressure, lung compliance, and airway resistance. The graphic read outs were then analyzed for a number of "dependent variables," and multiple regression analyses were performed using working pressure, PSV level, compliance, and resistance as "independent variables." The results show that the relative impact of working pressure on airway pressure and flow will vary with other lung and airway characteristics; also, excessive working pressure results in significantly greater flow rates at 40 ms after onset of inspiratory flow and at maximum flow, greater ringing or overshoot in the circuit, reduced tidal volume and inspiratory time, and reduced area under the airway pressure curve. In conclusion, adjusting ventilator working pressure will significantly affect lung-ventilator interaction in a quantifiable fashion. Further, these findings support clinical evidence that working pressure and/or initial flow rate need to be individualized to ensure optimal airway flow and pressure characteristics.

Airway Resistance↗

Maxillary extragonadal germ cell tumor: a case report.

A single case report of a patient with primary extragonadal endodermal sinus tumor affecting the maxillary region is reported here. The patient was treated with combination chemotherapy consisting of bleomycin, cisplatin and etoposide. The child achieved complete remission and is now disease free for three years.

Antineoplastic Combined Chemotherapy Protocols↗

Ascorbate-dependent formation of hydroxyl radicals in the presence of iron chelates.

The autoxidation of L-ascorbate on incubation in saline phosphate buffer (pH 7.4) is accompanied by hydroxyl radical (.OH) generation. The metal chelator EDTA showed significant inhibition of ascorbate autoxidation and ascorbate-dependent .OH release. On the other hand, Fe2+ (EDTA) greatly augmented both ascorbate autoxidation and ascorbate-dependent .OH production. The biological iron chelating compounds such as ATP, ADP, citrate and pyrophosphate suppressed both ascorbate autoxidation and ascorbate-mediated .OH production, thereby indicating that these compounds suppress the activating effect of iron. Ascorbate autoxidation and ascorbate-dependent .OH formation, stimulated by Fe2+ (EDTA) were significantly inhibited by .OH scavengers, namely mannitol, thiourea and sodium formate, as well as by catalase and to a lesser extent by bovine serum albumin, superoxide dismutase (native and heat denatured) and heat denatured catalase.

Adenosine Diphosphate↗

Unusual bone metastasis as the initial symptom of gastric cancer--a report of four cases.

Four cases of gastric cancer presenting with bone pain due to metastasis as the initial symptom are reported. Investigations revealed solitary osteolytic metastasis in the mandible in one, and left scapula in one patient. Third patient had multiple osteosclerotic metastasis with elevation of acid phosphatase and another had multiple discrete osteolytic metastasis simulating multiple myeloma. All the primary gastric cancers were poorly differentiated adenocarcinoma and three were of Borrman type III on gross appearance. One patient had sparing of the liver inspite of extensive metastasis. Chemotherapy was in effective in two patients and the prognosis was uniformly poor.

Adult↗