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Biomedical subjects

S Krishnamurthy

Publications and source records attributed to S Krishnamurthy.

At least 127 records · Page 7Linked to original sources
PubMed1986

Bactericidal effects of the neodymium:YAG laser: in vitro study.

The effects of laser energy on three bacterial strains, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were studied utilizing the neodymium:YAG laser. Cell suspensions of each strain were divided into four groups. In group I, suspensions from each strain were exposed to laser energy densities of 555-3,333 J/cm2. In groups II and III, two artificial dyes, congo red or methylene blue, were added to the suspensions prior to lasing. In group IVa, no laser energy was used, and group IVb was used to measure the bactericidal thermal effects of the laser. It was concluded that: Low dosages of laser energy exceeding 1,667 J/cm2 resulted in a 2 to 8 log decline in the number of viable bacterial colonies in vitro. Compared to the other two bacterial strains, P aeruginosa was the most sensitive to YAG laser irradiation. Addition of methylene blue, a dark-colored dye, enhanced the bactericidal effects of the YAG laser as indicated by the significantly reduced viability of P aeruginosa after irradiation with 2,222 J/cm2.

Catechols↗
PubMed1986

An inflammatory axonopathy of the myenteric plexus producing a rapidly progressive intestinal pseudoobstruction.

A previously well 39-yr-old man presented with a 4-wk history of abdominal pain, nausea, vomiting, and weight loss. An upper gastrointestinal examination showed retained food in the stomach and duodenal dilatation. A radioisotope meal showed little gastric emptying; esophageal manometry was normal. Because of persistent symptoms, a duodenojejunostomy was done. However, the patient remained symptomatic and after an episode of profuse vomiting, aspirated and died 10 wk after initial presentation. At autopsy, no tumor was found. Hematoxylin and eosin stains throughout the gastrointestinal tract showed many lymphocytes and plasma cells within the myenteric plexus. Silver stains showed the argyrophilic and argyrophobic neurons to be normal, but axons showed beading, fragmentation, and dropout in all areas. We therefore concluded the following: intestinal pseudoobstruction can be caused by an inflammatory neuropathy of the myenteric plexus, not associated with a distant carcinoma, and this process produced an axonopathy while sparing neuron bodies.

Adult↗
PubMed1985

Effects of varying intensities of laser energy on articular cartilage: a preliminary study.

The effects of laser energy on articular cartilage were studied utilizing the neodymium YAG laser. Partial-thickness cartilage defects were surgically attempted in the femoral condyles of knee joints in guinea pigs. The defects were exposed to laser energy of varying intensities [group I, 25 J (5 W X 5 sec); group II, 75 J (15 W X 5 sec); group III, 125 J (25 W X 5 sec)]. A fourth group was studied, in which the defect was not lased. Animals were killed at weekly intervals from 1 to 6 weeks and the knee joints were subjected to histological analysis. At 5 weeks, the knees exposed to 25 and 75 J demonstrated a reparative process with chondral proliferation. The knees exposed to 125 J demonstrated fibrotic tissue and tissue necrosis that resulted in fibrosis. In the knees not exposed to laser energy, numerous foci of granulation tissue were present at all stages with the end point of healing being one of fibrosis with disorganized patchy cartilage islands.

Animals↗
PubMed1985

Intestinal pseudoobstruction caused by a new form of visceral neuropathy: palliation by radical small bowel resection.

We report a case of chronic intestinal pseudoobstruction caused by a newly recognized type of degenerative neuropathy of the myenteric plexus. Failure to improve despite aggressive medical management led to radical resection of the clinically involved small intestine. At follow-up 10 mo later, the patient is doing well without the need for parenteral nutrition. Radical resection of the small intestine may be necessary for palliation in rare patients with intractable pseudoobstruction.

Adult↗
PubMed1985

Severe idiopathic constipation is associated with a distinctive abnormality of the colonic myenteric plexus.

We analyzed the clinical, radiographic, esophageal manometric, and pathologic features of 26 women with severe, idiopathic constipation. Twenty-four patients were between 19 and 39 yr of age. Stool frequency was once every 5-28 days. On barium enema examination, 9 of 24 patients had colons of increased length and 4 of these 9 patients had colons of increased width (greater than 10 cm). Radionuclide solid-meal gastric-emptying studies were normal in 23 patients tested. Esophageal manometry demonstrated high-amplitude waves in 10 of 22 patients and long-duration waves in 3 of these 10 patients. Rectal biopsy specimens showed normal submucosal neurons in all patients and melanosis coli in 6. Twelve patients underwent subtotal colectomies for constipation. Conventional light microscopy using hematoxylin and eosin serial sections showed (a) melanosis coli in 4 patients; (b) normal smooth muscle in 11; (c) thinning of the circular muscle in 1; and (d) no apparent abnormalities of the myenteric plexus in any. In contrast, silver stains of the myenteric plexus showed (a) quantitatively reduced numbers of argyrophilic neurons in 10 patients; (b) morphologically abnormal argyrophilic neurons in 11; (c) decreased numbers of axons in 11; and (d) increased numbers of variably sized nuclei within ganglia in all 12. A coded analysis of the silver stains of colons from 8 patients with constipation and 19 control cases demonstrated that the pathologic abnormalities of severe idiopathic constipation could be differentiated from controls. Thus, severe idiopathic constipation is associated with a pathologically identifiable abnormality of the myenteric plexus. This abnormality appears different from anything previously described in intestinal pseudoobstruction.

Adult↗
PubMed1985

The role of physiologic monitoring in patients with fractures of the hip.

Mortality rates for elderly patients with hip fractures have been reported to be as high as 37%. This study evaluated 70 patients of whom 35 were evaluated preoperatively by conventional diagnostic means, and 35 in whom hemodynamic, respiratory, and metabolic status was assessed using a Swan-Ganz balloon-tipped catheter. The derived variables were then calculated by a minicomputer and automatically plotted on a printed graphic display in a bar graph format. This diagnostic modality permitted appreciation of occult physiologic aberrations not detected by conventional methods, enabling correction of these abnormalities preoperatively and postoperatively. The study demonstrated a mortality rate of 2.9% in the monitored group compared to a 29% mortality in the nonmonitored group. The intrinsic assumption that patients should undergo surgery within 24 hours (3) was also modified. The appropriate time for surgery should be accurately determined and chosen on the basis of optimal physiologic balance.

Adult↗
PubMed1985

Pure posteromedial dislocation of the ankle joint. A case report.

A 25-year-old man demonstrated a complete dislocation of the tibiotalar joint, caused by an axial loading injury in which he had fallen to the ground with his foot and ankle in supination. This was associated with disruption of the lateral ligamentous complex. Management consisted of immediate reduction, intravenous antibiotics, formal debridement, and ankle immobilization in a short leg cast. Early and delayed follow-up evaluations have revealed no complications resulting from the injury. Only seven cases of open posterior medial tibiotalar dislocation seem to have been reported previously in the literature.

Adult↗
PubMed1984

A study of the ultrastructure of urinary calculi by scanning electron microscopy.

A study of urinary stones obtained from patients after surgery in the Medical College Hospital, Trivandrum, under the scanning electron microscope showed the presence of calcium oxalate and calcium biphosphate crystals as the main constituents. However, the pattern of the different phases of crystal growth was not uniform. Within the crystal lattice, fibrous structures, possibly of protein matrix, were invariably observed. Electron microscopy may be usefully adapted as a particularly suitable method for ultramicroscopic investigation of the fine structure of urinary stones including single crystal surface structure, section of urinary calculi and for possible presence of hitherto unknown components within the calculus.

Calcium Oxalate↗
PubMed1984

A gross anatomic and histologic study of the innervation of the proximal interphalangeal joint.

The innervation of the proximal interphalangeal joint was studied by gross dissection with magnification and histologic analysis. The joint is innervated by a constant articular branch arising from the palmar proper digital nerve at the level of the midproximal phalanx. This articular nerve bifurcates adjacent to the joint, and its terminal branches enter the joint in the midlateral plane at the junction of the palmar plate and lateral capsule. No contribution to the articular innervation was found to arise from the sensory radial, dorsoulnar cutaneous, and collateral branches of the proper digital nerve that cross the joint. The innervation of the proximal interphalangeal joint is congruent with the palmar sensory innervation and has no relation to the dorsal sensory innervation.

Finger Joint↗
PubMed1984

Radiologic and histologic differentiation of neuromuscular disorders of the gastrointestinal tract: visceral myopathies, visceral neuropathies, and progressive systemic sclerosis.

Forty patients with neuromuscular disorders of the gastrointestinal tract were evaluated histologically and radiologically. Eighteen patients with progressive systemic sclerosis had predominant circular muscle thinning and fibrosis. Visceral myopathy (11 patients) was characterized by vacuolar degeneration of the smooth muscle cells with thinning and fibrosis typically affecting the longitudinal layers. Visceral neuropathy (five patients) had degeneration of myenteric plexus neurons with various patients having intranuclear inclusions, Schwann cell proliferation, or inflammatory cell infiltration. Radiologically, these syndromes had diffuse abnormalities of gastrointestinal motor function manifested by small and large intestinal dilatation, esophageal hypomotility (progressive systemic sclerosis and visceral myopathy), or disordered hypercontractility (visceral neuropathy). Marked duodenal enlargement typified visceral myopathy, and although all types may have dilated small intestine, only progressive systemic sclerosis has packing of valvulae. Colonic sacculations were found in progressive systemic sclerosis, lack of haustrations and increased colonic caliber in visceral myopathy, and hypercontractility in visceral neuropathy. Complete barium contrast examination will assist in differentiation of true obstruction from pseudoobstruction, will define the diffuse nature of the syndrome, and will help establish an accurate diagnosis by identifying features specific for these entities.

Esophagus↗
PubMed1984

Megacolon and neurofibromatosis: a neuronal intestinal dysplasia. Case report and review of the literature.

This study presents the case of a patient with neurofibromatosis and megacolon. A diffuse, but patchy abnormality of neural tissue was present throughout the colon, especially in the myenteric plexus, but also in the submucosal plexus, smooth muscles, and lamina propria. This consisted of (a) a marked decrease in the number of argyrophilic neurons within the myenteric plexus, enlargement and deformity of those neurons present, and a marked increase of nerve fibers and nerve tract size in the myenteric plexus; (b) a proliferation of neurons and nerve fibers within the smooth muscle and submucosa; and (c) a proliferation of nerve fibers within focal areas of the lamina propria. The relationship of this case to previously reported cases of neuronal intestinal dysplasia and plexiform neurofibromatosis is discussed. Surgical treatment may be necessary and the surgical options are reviewed.

Colonic Neoplasms↗
PubMed1984

Serum vitamin E and lipid peroxides in malnutrition, hyper and hypothyroidism.

Serum lipoperoxides were measured, by a modified thiobarbituric acid method, in 25 children affected with malnutrition, 40 adults having hyperthyroidism and 40 adults having hypothyroidism and compared with the serum lipoperoxides content of 40 normal adults. The lipid peroxide content was 3.9 nmol/ml in normals, 1.8 nmol/ml in malnutrition, 2.5 nmol/ml in hyperthyroidism and 3.1 nmol/ml in hypothyroidism. The vitamin E content of the serum in all the cases was found to vary in the same way as the amount of circulating lipid peroxides. The serum inhibitory capacity against in vitro lipid peroxidation, using rat brain homogenate as a model system, was totally abolished in malnutrition and was decreased to about 50% in hyperthyroidism and to about 33% in hypothyroidism, as compared to normal human serum. It is concluded that the level of circulating lipid peroxides in serum is related to the serum vitamin E concentration.

Adolescent↗
PubMed1983

Jejunal diverticulosis. A heterogenous disorder caused by a variety of abnormalities of smooth muscle or myenteric plexus.

We analyzed the clinical, radiographic, esophageal manometric, and pathological features of 10 patients referred with jejunal diverticulosis. Nine patients were over age 59 yr and had symptoms of intestinal pseudoobstruction of 5-43 yr duration. Seven had surgery for mechanical obstruction, although none was found. Eight had diarrhea, steatorrhea, and weight loss. Five had Raynaud's phenomenon and heartburn, and 2 had dysphagia. At radiography, 9 had jejunal diverticula with or without duodenal or ileal diverticula, or both. Two each had abnormal structure or motility of the esophagus or stomach. At manometry, 3 of 7 had a nonspecific motor abnormality, and 1 other had low amplitude peristaltic waves. Light microscopy of small intestinal tissue in 7 patients showed that 4 had fibrosis and decreased numbers of normal-appearing muscle cells, findings consistent with progressive systemic sclerosis. Two others had fibrosis associated with degenerated smooth muscle cells, findings consistent with a visceral myopathy. The seventh patient had neuronal and axonal degeneration and neuronal intranuclear inclusions, findings consistent with a visceral neuropathy. We conclude that (a) intestinal pseudoobstruction is a major clinical manifestation of jejunal diverticulosis, (b) jejunal diverticulosis is a heterogenous disorder associated with at least three abnormalities of the smooth muscle or myenteric plexus, (c) in contrast to intestinal pseudoobstruction without diverticulosis, the esophagus, stomach, and colon are less frequently involved in jejunal diverticulosis, and (d) some patients with jejunal diverticulosis probably have clinically inapparent progressive systemic sclerosis.

Adult↗