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Biomedical subjects

M Koss

Publications and source records attributed to M Koss.

At least 55 records · Page 3Linked to original sources

Sarcoidosis and amyloidosis. Is the association causal or co-incidental?

During 1950-83, 52,371 autopsies were done at the Los Angeles County Hospital; 503 cases showing amyloidosis, seven of these also had sarcoidosis, and three also had rheumatoid arthritis. These associations could be coincidental or it is just possible that there is a causal aetiological relationship. It is hoped that other workers will review their material, and, in particular, to assess whether there is an increased incidence of amyloidosis in sarcoidosis.

Adult↗

Malignant peripheral nerve sheath tumor arising in an adrenal ganglioneuroma in an adult male homosexual.

The authors report a case of malignant peripheral nerve sheath tumor arising in an adrenal ganglioneuroma in an adult. This is the first such case occurring in the absence of a history of childhood neuroblastoma treated with radiation, and provides evidence that such a transformation can occur spontaneously. The neoplasm demonstrated a highly malignant biologic behavior with rapid growth, local recurrence, and metastasis.

Adrenal Gland Neoplasms↗

Incidence and mortality of adult respiratory distress syndrome: a prospective analysis from a large metropolitan hospital.

We examined the incidence and mortality of adult respiratory distress syndrome (ARDS) in patients receiving emergency medical care at a large metropolitan medical center. The patients were classified into eight high-risk categories and monitored prospectively until discharge or death. Over a period of 12 months, 11,112 such patients entered the emergency room. Of 4926 who were admitted to the hospital acutely ill, 90 (2%) developed ARDS. Thirty-six percent of these survived. ARDS occurred in 25% of patients admitted with acquired immune deficiency syndrome and Pneumocystis carinii pneumonia, and mortality in these patients was 86%. Aspiration pneumonia was the primary cause of ARDS in 37% of the patients, who also had a similar mortality rate (85%). Mortality was also high in patients with multisystem organ failure or with ARDS and disseminated intravascular coagulation. These results indicate that there probably is a relatively low incidence of ARDS among hospital patients admitted with high-risk diagnoses.

Acquired Immunodeficiency Syndrome↗

Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome (AIDS). Diagnosis with bronchial brushings, biopsy, and bronchoalveolar lavage.

Sixty-one diagnostic biopsies for Pneumocystis carinii pneumonia were performed on 40 homosexual male patients with acquired immunodeficiency syndrome (AIDS), using flexible fiberoptic bronchoscopy. Bronchial brushings and bronchoalveolar lavage were performed in conjunction with the biopsy in 58 and 29 bronchoscopies, respectively. Using a rapid methenamine silver stain, P carinii pneumonia was diagnosed in 27 (68 percent) of the patients. Twenty of these patients had a repeat biopsy one or more times for evaluation of therapy. Eighteen of the biopsies following two to three weeks of therapy were positive. There was an 84 percent correlation between findings on transbronchial brushing and biopsy (89 percent on initial biopsy before treatment) and an 86 percent correlation between bronchoalveolar lavage and biopsy. Additionally, transbronchial brushing permitted demonstration of Pneumocystis organisms in four follow-up bronchoscopies in which the biopsy was negative or inadequate. Rapid methenamine silver stain of transbronchial brushings permits diagnosis of P carinii pneumonia in patients with AIDS within one-half hour of bronchoscopy.

Acquired Immunodeficiency Syndrome↗

Ultrastructural and pharmacologic studies on laser-induced glaucoma in primates and rabbits.

Sustained high intraocular pressure resulting in optic nerve cupping and loss of ganglion cells was produced in five rhesus monkeys and eight pigmented rabbits by applying argon laser energy to the trabecular meshwork. In addition, the rabbits manifested buphthalmus. Flow of carbon particles subsequently injected into the anterior chamber was obstructed at the trabecular meshwork by a wound-healing response that closed the intratrabecular spaces. Besides this sustained high intraocular pressure as a result of late scarring, an acute hypertensive response was seen in all rabbits which may correspond to the acute hypertension seen after laser trabeculoplasty in humans. The acute hypertensive response could be only partially blocked by prostaglandin inhibitors and we believe that prostaglandins are not primarily responsible for this effect. Medications known to lower intraocular pressure were systematically tested in both glaucoma models.

Animals↗

Immunopathologic and clinical studies in pulmonary hypertension associated with systemic lupus erythematosus.

PH is an uncommon manifestation of SLE. The symptoms of PH develop within a few years after the onset of the multisystem disease. The most common presenting complaints of SLE patients with PH are dyspnea on exertion, chest pain, nonproductive cough, edema, and fatigue or weakness. The important physical findings are a loud second pulmonic heart sound and a right ventricular lift. The chest roentgenogram shows a cardiomegaly, a prominent pulmonary segment, and usually clear lung fields. Pulmonary function tests may show evidence of restrictive lung disease; however, the physiologic abnormalities are mild and out of proportion to the severity of the PH. The diagnosis of PH is established by cardiac catheterization showing elevated pulmonary artery pressure, normal capillary wedge pressure, and no evidence of intracardiac or extracardiac shunts. Pathologic examination of the lung demonstrates angiomatoid lesions involving muscular pulmonary arteries. There is a thickening of the media and subintima of the arterioles. Immunoglobulin and complement deposits are found in the walls of pulmonary arteries. Immunoglobulin eluted from the lung contains rheumatoid factor and antinuclear antibody including antibody to DNA activity. DNA antigen is also present in walls of blood vessels. These results suggest an immune complex deposition process as a mechanism in the pathogenesis of PH in SLE. The clinical course of PH in SLE is variable. Symptoms may be mild and the disease follows a stable and protracted course for several years. It can, however, develop a progressive course ending in death in a few years. The clinical response of SLE patients with PH to treatment with high doses of systemic corticosteroids is not consistent or predictable.

Adrenal Cortex Hormones↗

Asbestos exposure and lymphomas of the gastrointestinal tract and oral cavity.

An epidemiological case-control study of non-Hodgkin's lymphomas revealed an excess of male patients with large-cell lymphomas primary to the gastrointestinal tract and oral cavity who had evidence of substantial exposure to asbestos. Between 1977 and 1981, 28 men with large-cell lymphomas primary to these sites were interviewed about previous environmental exposure. Pathology slides from 26 of these cases were reviewed by haematopathologists, who confirmed each to be non-Hodgkin's lymphoma of large-cell type. Neighbourhood controls were matched to patients for age, race, and sex. 13 matched pairs were discordant for asbestos exposure, and in 12 of these the exposed individual was a lymphoma patient. 10 patients and 1 control also reported a history of malaria.

Adult↗

Central sympathetic reactivity inhibited by indoramin.

The action of indoramin on central autonomic activity was investigated using the sympathetic-cholinergic electrodermal response system. Indoramin (0.33-10 mg/kg, i.v.) significantly reduced the amplitude of electrodermal responses (EDR) evoked by stimulation of the hypothalamus in a dose-related manner. The CNS effects of indoramin on the EDR were partially antagonized by yohombine pretreatment. These results demonstrate that indoramin reduces central sympathetic reactivity and suggest that an alpha-adrenergic inhibitory mechanism may be involved.

Animals↗

Pulmonary veno-occlusive disease secondary to granulomatous venulitis.

Pulmonary veno-occlusive disease is a rare disorder characterized by an obliterative fibrosing venulitis. The etiology and pathogenesis of this disease is not well understood. This case is one secondary to granulomatous venulitis. Ultrastructural study demonstrated reduplication of capillary basal laminae, endothelial swelling, and granuloma formation, but shed no light on the etiology of the disease. The formation of noncaseating granulomas involving only intralobular veins is most unusual and has not been previously described in pulmonary veno-occlusive disease.

Adult↗

The kidney in streptozotocin diabetic rats. Morphologic, ultrastructural, and function studies.

In order to study the nephropathy associated with experimental streptozotocin diabetes, serila morphologic, ultrastructural, immunohistologic, and functional studies were done in diabetic Lewis rats to study the course of the nephropathy. Early in the course of diabetes, these animals developed an increase in mesangial matrix, with electron-dense material, IgG, and C3 in the mesangium. These alterations were progressive. Mesangial bars, proximal tubular vacuolization, and myeloid bodies were also present. Progressive increase in protein excretion and increase in creatinine clearance were observed. Hyperglycemia was accompanied by weight loss, persistent glycosuris, hyperphosphaturia, and hypercalcuria. Urinary glomerular basement membrane-like protein and major urinary protein were decreased. Normal age-matched controls showed no abnormalities. Some of the changes observed in diabetic rats are present in human diabetes.

Animals↗

Malignant hypertension resulting from deoxycorticosterone acetate and salt excess: role of renin and sodium in vascular changes.

The evolution of malignant hypertension was studied under metabolic balance conditions in 11 uninephrectomized rats given deoxycorticosterone acetate and 1% NaCl as drinking water. Changes in sodium and potassium balance were related to changes in blood pressure, plasma renin activity, hematocrit, and kidney histology. After 3-4 weeks of steadily positive sodium balance accompanied by continuously increasing blood pressure up to 185 plus or minus 19 (SE) mm Hg, periods of sodium loss accompanied by evidence of hemoconcentration were observed marking the onset of the malignant phase as defined by the development of fibrinoid necrosis in the kidney. Plasma renin activity remained markedly suppressed both at the fourth week (0.33 plus or minus 0.02 ng/ml hour-1) when the sodium balance was positive and the kidney biopsy negative and at the end of the experiment (0.35 plus or minus 0.36 ng/ml hour-1) when the sodium balance was negative and the kidney histology revealed malignant vasculitis. Infusion of the angiotensin II inhibitor 1-Sar-8-Ala-angiotensin II consistently failed to affect blood pressure, and the kidney tissue norepinephrine level was reduced (0.054 plus or minus 0.01 mug/g) compared with the control level (0.132 plus or minus 0.02 mug/g). We conclude that malignant vasculitis in this model is preceded by hypertension associated with sodium and water retention and is accompanied by negative sodium balance, decreases in body weight, falling blood pressure, and hemoconcentration without demonstrable participation of the renin-angiotensin system or the renal catecholamines.

Alanine↗

Cardiac heterotransplantation. Morphological and immunohistological studies.

A vascularized heterograft model using outbred strains of animals was developed by transplanting mouse hearts heterotopically into rats. With this species desparity rapid but not immediate graft rejection was observed, with a predictably narrow range of graft survival times. Morphological and immunohistological studies showed early deposition of fibrinogen and vascular and myocardial inflammation without prominent or consistent localization of either IgG or C3. Later more extensive changes were observed, and deposition of IgG and C3 were more prominent in the grafts. Pretreatment of the recipient with cyclophosphamide alone or cyclophosphamide plus antigen prolonged graft survival; however, no statistically significant difference was noted between these groups. Morphological and immunohistological alterations preceded clinical rejection, and tissue injury appeared to be mediated by humoral and cellular immune mechanisms and by the coagulation system. This model is potentially useful for the study of heterotransplantation.

Animals↗