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Biomedical subjects

S Parikh

Publications and source records attributed to S Parikh.

At least 73 records · Page 4Linked to original sources

Renal manifestations of AIDS.

The kidneys in patients with acquired immunodeficiency syndrome (AIDS) are subject to a variety of insults. Renal manifestations can be seen with imaging studies of AIDS patients. Computed tomographic (CT) and ultrasound (US) scans of 64 patients with AIDS and renal dysfunction were retrospectively reviewed and compared with clinical, laboratory, and, when available, biopsy results. Imaging abnormalities included increased cortical echogenicity, nephromegaly, pyelonephritis, lobar nephronia, focal masses caused by abscess and lymphoma, parenchymal calcification, hydronephrosis, and infarct. Generally, patients with AIDS as a result of intravenous drug abuse and those with multiple risk factors were more likely to have abnormalities demonstrated at imaging as well as poorer prognosis than were patients in the homosexual transmission group in this series. Although US should be the screening study used in patients with AIDS and suspected renal dysfunction, CT and magnetic resonance imaging may be necessary to identify focal infectious, ischemic, and neoplastic processes.

Acquired Immunodeficiency Syndrome↗

Role of the neutrophil in abdominal aortic aneurysm development.

Elastase release by neutrophils has been implicated in the etiology of abdominal aortic aneurysm (AAA). The present study investigated whether neutrophils in patients with AAA actively synthesize the neutrophil elastase enzyme and the effect of elastin-derived peptides on neutrophil elastase release. Total neutrophil elastase in patients with AAA was significantly higher than in those with aortic occlusive disease and controls. The neutrophil elastase gene was not expressed in any patient group. Elastin-derived peptides induced elastase release, which was significantly higher in patients with AAA than in those with aortic occlusive disease and controls. These data indicate that the peptides of elastin degradation stimulate the release of elastase, but that continuing production of elastase is absent in circulating neutrophils. It is concluded that: (1) neutrophils do not actively synthesize elastase but act as 'mules' or carriers of the enzyme; and (2) elastin breakdown products stimulate the release of elastase at the aortic wall by circulating neutrophils, which in patients with AAA have a predetermined increased amount of elastase.

Aorta, Abdominal↗

Polymorphonuclear leukocyte functions in children with cyanotic and acyanotic congenital heart disease.

Eighteen cyanotic congenital heart disease (CCHD) and 17 acyanotic congenital heart disease (ACHD) patients in the age range of 2 months to 10 years along with their age and nutrition matched controls were studied for bactericidal, chemotactic and phagocytic functions. Bactericidal and phagocytic functions were significantly depressed in CCHD (p < 0.001) as well as ACHD group (p < 0.001) compared with controls. Chemotactic function was not significantly affected in either. Arterial oxygen content (as a measure of hypoxia) was calculated for each patient and correlated with each immune parameter by univariate linear regression analysis. In CCHD patients linear correlation of borderline significance (p = 0.07) was found between arterial oxygen content and bactericidal activity, but no correlation could be established with phagocytic and chemotactic functions. No correlation was obtained between hematocrit and any of the immune parameters. In ACHD patients no correlations were obtained between the immune parameters and arterial oxygen content or hematocrit. Iron deficiency anemia, known to affect bactericidal function, did not seem to affect the immune parameters in CCHD and ACHD groups. Altered oxygen content of the blood owing to hypoxia in CCHD patients may be an important etiological factor in the genesis of bacteremia and cerebral abscess. The affection of immune functions in ACHD cannot be adequately explained.

Child↗

Perioperative stroke after general surgical procedures.

Perioperative cerebrovascular accidents after general surgical procedures are rare, but devastating and often fatal. The purpose of this study was to identify the perioperative, intraoperative, and postoperative factors associated with perioperative strokes after general surgical procedures. Over a five-year period, 19 patients of 24,641 general and vascular surgical procedures (0.08%) suffered a perioperative stroke. Patients undergoing carotid endarterectomies were excluded. These 19 patients were compared with a group of 19 patients matched for age and procedure. The strokes occurred in relation to the surgery as follows: 53% within 24 hours, 31% within one to seven days, and 16% within seven to thirty-six days. The overall perioperative mortality was 26%. In long-term follow-up, four patients died, two had complete recovery (11%), two had 90% recovery (11%), one had partial recovery (5%), and one remained completely disabled (5%). In comparing the groups, the significant factors contributing to perioperative stroke included hypertension, smoking, earlier neurological symptoms, and an abnormal rhythm on electrocardiogram. The most common factor for stroke was atrial fibrillation. Only one patient had an intracerebral hemorrhage. Although the exact mechanism of perioperative stroke remains uncertain, its association with abnormal cardiograms, lack of association with carotid bruits, and lack of intracerebral hemorrhage all suggest that emboli from the heart is the major cause in most patients. These data indicate that a perioperative stroke is associated with a very high mortality rate (26%) and is a potentially predictable complication in the majority of patients.

Adult↗

Increased intestinal permeability: implications for thoracoabdominal aneurysm repair.

Coagulopathy and massive bleeding plays a major role in the mortality of thoraco-abdominal aneurysm repair. Increasing supraceliac aortic cross-clamp time from 0 to 90 minutes increases the degree of disseminated intravascular coagulation, which occurs as a result of occlusion and reperfusion of the superior mesenteric artery. The purpose of this study was to investigate the mechanism of the superior mesenteric artery reperfusion disseminated intravascular coagulation. Twenty dogs were divided into four groups: cross-clamp time of 30 minutes; cross-clamp time of 60 minutes; cross-clamp time of 90 minutes; and control. Permeability was determined by lactulose/mannitol absorption. The venous effluent was sampled for endotoxin, potassium, bacteria, and pH every hour and urine was collected for six hours. Lactulose absorption was significantly higher in all of the experimental groups. There was increased permeability in the 60 and 90 minute groups which correlated significantly with time. Venous endotoxin, potassium, and blood cultures for bacteria did not change significantly. The pH was significantly lower every hour for six hours in the 90 minute group. These data suggest that intestinal permeability is increased with supraceliac aortic clamping and can be kept to a minimum for clamp times of under one hour.

Animals↗

Pheochromocytoma and pregnancy: report of three cases.

Three cases of pheochromocytoma associated with pregnancy are reported. Two patients had adrenal pheochromocytoma coexistent with normal pregnancy and one patient had a bladder pheochromocytoma coexistent with molar pregnancy (gestational trophoblastic disease). The diagnosis was made antenatally in the two normal pregnancy patients, both underwent planned tumor resection, one at mid-trimester, complicated by postoperative miscarriage, while the other had tumor resection during cesarean section at term. Bladder pheochromocytoma, preoperatively mistaken for invasive trophoblastic tumor, was resected at the time of planned abdominal hysterectomy for molar pregnancy, pheochromocytoma was recognized only after microscopic study of the resected bladder tumor. The three patients survived with no evidence of disease.

Adrenal Gland Neoplasms↗

Molecular cytogenetics of alpha satellite DNA from chromosome 12: fluorescence in situ hybridization and description of DNA and array length polymorphisms.

A 340-bp EcoRI fragment of alpha satellite DNA from human chromosome 12 has been isolated and used in molecular cytogenetic and genetic studies. The clone, pSP12-1, detects tandemly repeated 1.4-kb repeat units at the centromeric region of chromosome 12. By fluorescence in situ hybridization, biotinylated pSP12-1 is highly specific for chromosome 12 and has been used to confirm an i(12p) in a case of Pallister-Killian syndrome, both in metaphase spreads and in interphase nuclei. A dominant DNA polymorphism for the centromeric D12Z3 locus is detected with the enzyme TaqI. In addition, a high frequency of D12Z3 array length polymorphisms can be detected using pulsed-field gel electrophoresis. The D12Z3 array has been measured by pulsed-field gel electrophoresis to span approximately 2,250-4,300 kb at the centromeric region of chromosome 12.

Centromere↗

Echinococcal infestation of the spine in North America.

Taenia echinococcal infestation, a parasitic disease rarely seen in the United States, occurred in a 62-year-old man. Bone is involved in about 1% of all cases, and of these cases, the spine is involved in about 50%. Preoperative identification is difficult because of lack of characteristic radiographic features. Successful management is also problematic because of the difficulty of preoperative diagnosis, the invasive nature of the bony involvement, and the variable anaphylactic reaction to the cyst fluid antigen. The diagnosis must be entertained in the differential diagnosis of benign spinal neoplasms especially when dealing with patients from endemic areas.

Echinococcosis↗

Night backache in pregnancy. Hypothetical pathophysiological mechanisms.

One hundred women responded to a questionnaire dealing with night backache during pregnancy. All the women were in the second half of their pregnancy. Sixty seven per cent of the women reported discomfort and/or backache during the night. We hypothesize that hypervolemia combined with obstruction of the inferior vena cava, caused by the enlarging uterus, is the underlying pathomechanism leading to night backache. Patients with inadequate venous collateral circulation may develop excessive pressure within the venous system, the vertebral bodies and overdistension of venous channels distal to the occluded zone. These changes may lead to hypoxemia, metabolic disturbances, irritation of unmyelinated nerves and result in night backache.

Back Pain↗

The shoulder abduction relief sign in cervical radiculopathy.

A patient with C6 cervical radiculopathy reported that sustained shoulder abduction significantly diminished this upper extremity pain. The patient was instructed to adopt this position for prolonged periods during rest and at work. Pain relief was temporary and lasted as long as the arm was in abduction. Relief of pain, induced by arm abduction, may be observed in cervical radiculopathy in which the lower cervical roots are involved. Reduced tension at the nerve root is the probable underlying mechanism that leads to pain relief. Shoulder abduction can be used not only as a diagnostic sign but also may be incorporated in the conservative management of patients suffering from cervical radiculopathy affecting the lower cervical roots.

Humans↗

Dermatitis-sympathetic dysfunction in carpal tunnel syndrome. A case report.

A 52-year-old woman complained of numbness affecting the thumb, index, and middle fingers of both hands. The patient was managed with night splints with partial relief of symptoms. As a house cleaner, the patient was routinely exposed to water and detergents. About a year later, the patient developed contact dermatitis in the fingertips innervated by the median nerves. Electromyographic studies confirmed the presence of bilateral carpal tunnel syndrome. The temperature of all the fingertips was measured. The median innervated fingertips were warmer than those innervated by the ulnar nerves. The median sympathetic fibers may be compromized by compression in the carpal tunnel. This caused vasodilation, increased finger temperature, and lack of sweating in the median innervated fingers. Due to regular exposure to water and detergents, the susceptible dry fingertips developed contact dermatitis. The patient was managed conservatively, and the rash and numbness disappeared.

Carpal Tunnel Syndrome↗

Spine fractures in ankylosing spondylitis.

Patients with ankylosing spondylitis are susceptible to spine fracture, usually in the cervical spine. Less frequently, the thoracic and lumbar spine is affected. The fracture line may involve anterior and posterior elements. Frequently, it extends through the entire width of the spine. As a result the fracture tends to be unstable and may cause neurologic damage. Prompt immobilization and reduction of the dislocated spine followed by stabilization may prevent neurologic damage. We report a 45-year-old man who fell and sustained a fracture dislocation of L2 vertebra. The patient was operated and stabilized with Harrington rods. A deep wound infection developed, which did not respond to antibiotic therapy and led to removal of the rods. In spite of bed immobilization with a body jacket the fracture remained unstable and dislocated. As a result the patient sustained severe neurologic damage. Many fractures in patients with ankylosing spondylitis occur following minor trauma. We feel that a very important aspect of ankylosing spondylitis management is prevention of these fractures. Alerting patients of their spine fragility and teaching then how to evade situations leading to spinal trauma may help in avoiding this situation.

Fractures, Bone↗

Drug-induced asthma: a review.

A review of clinical and experimental data pertaining to drug-induced asthma is presented. Various drugs and drug additives causing asthma are classified and their possible modes of action in inducing asthma are discussed. Practical recommendations for diagnosis and prevention of drug-induced asthma are enumerated.

Alfaxalone Alfadolone Mixture↗

A visual index of thyroid function.

A visual index of thyroid uptake (VITU) is introduced as a qualitative measure of thyroid trapping. This index is determined from the 20-minute 99mTc-pertechnetate scan by visually comparing the relative tracer uptake between the thyroid and salivary glands. Three categories are defined: low, normal and elevated. The VITU correctly identified the functional status of the thyroid in 94% of 123 patients studied and agreed with the 24-hour radioiodine uptake (RAIU) in 89%. The VITU is a very simple but highly accurate, reliable and reproducible test. It was primarily designed to complement other tests of thyroid function by contributing qualitative information about the thyroidal trapping mechanism, but it can also be useful in confirming blood tests of thyroid function in cases in which one would prefer to avoid 131I administration for RAIU studies.

Diagnostic Errors↗