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Biomedical subjects

A Haas

Publications and source records attributed to A Haas.

At least 127 records · Page 7Linked to original sources
PubMed1987

Protection from radiation enteritis by an absorbable polyglycolic acid mesh sling.

Patients with malignant tumors of the pelvis who cannot be cured surgically often are treated with radiation after surgery. A devastating side effect of this treatment is radiation-associated small bowel injury (RASBI). The purpose of this study was to test the hypothesis that removal of the small bowel from the radiation field would protect it against RASBI. Twenty cebus monkeys underwent low anterior resection. In 10 animals an absorbable polyglycolic acid (PGA) mesh was sewn circumferentially around the interior of the abdominal cavity as a supporting apron, which prevented the small bowel's descent into the pelvis. The other 10 monkeys did not receive the mesh. All animals received 2000 rads by linear acceleration in a single dose. Twenty-four-hour stool fat, serum vitamin B12, and other serum values were obtained during the study. Animals were sacrificed after 1, 2, 3, 6, and 12 months, and the small bowel and rectum were examined histologically in a blind manner. Two monkeys who did not undergo surgery, or exposure to radiation served as controls. At all sacrifice periods, the animals with PGA mesh slings demonstrated normal small bowel function and histologic structure. Animals without mesh slings had abnormal stool and blood values at 1 month, and by 2 months all had died of small bowel necrosis. The animals that received the slings had no evidence of infection or obstruction, and by 6 months all evidence of the mesh was gone. Support of the small bowel out of the pelvis by an absorbable PGA mesh sling protects against RASBI and is without apparent complications.

Animals↗
PubMed1986

Detection of a tyrosine kinase in human sera and blood cells by pp60src antiserum.

Using sera of Rous sarcoma virus-tumor bearing rabbits (TBR-sera) as a tool to detect pp60src kinase in immunoprecipitates, we report here that about 10% of our TBR-sera revealed tyrosine kinase activity in human serum, plasma and in soluble extracts of human blood cells. The activity found in serum represents 5-12% of the total kinase activity in blood. Most of the enzyme activity was detected in lymphocytes and polymorphonuclear cells rather than in platelets and erythrocytes. We also demonstrate that the tyrosine kinase in serum is inhibited by quercetin, a potent inhibitor of the viral pp60src protein kinase.

Blood Cells↗
PubMed1986

Influence of age on the visual fields of normal subjects.

We studied the influence of age on the results of automated static perimetry in 203 eyes of 153 healthy volunteers tested with an automated perimeter. Differential light sensitivity decreases markedly with age and this decrease starts at the age of 20 years or less and continues more or less linearly during life. The decrease in sensitivity differs at different test locations. Age influences the upper half of the visual field to a larger extent than the lower half; the periphery and the center are more influenced than the pericentric area.

Adolescent↗
PubMed1986

Takayasu's arteritis presenting as pulmonary hypertension.

Takayasu's arteritis (pulseless disease) is a vasculitis that affects the large arteries, including the aorta, its branches, and the pulmonary arteries. A 15-year-old girl with Takayasu's arteritis was referred to our institution for marked pulmonary hypertension in the absence of symptoms referable to systemic vasculitis. She was shown to have a thickened, narrowed thoracic aorta, a stenosed right axillary artery, and severely affected pulmonary arteries. Despite corticosteroid therapy she died one month after diagnosis. This patient's illness indicates that pulmonary vessels might be the principal vessels involved in Takayasu's arteritis.

Adolescent↗
PubMed1986

Infectious complications of the primary immunodeficiencies.

The primary manifestation of the immunodeficiencies is undue susceptibility to infection. This means too many, too severe, too prolonged, too complicated and too unusual infections. Infections in immunodeficiency have a characteristic cause depending on the nature of the immune deficiency. Antibody deficiencies are associated with infections with gram-positive infections. Cellular immune deficiencies are associated with mycobacterial, protozoan, fungus, virus, and opportunistic bacterial infection. Phagocytic disorders are associated with staphylococcal, fungal, and gram-negative organisms. Complement disorders are associated by neisserial infections. Infections have also been implicated in the pathogenesis of some immunodeficiencies in some circumstances. These include human T lymphotropic virus type III (HTLV-III), rubella virus, cytomegalovirus, and Epstein-Barr virus. Several infectious syndromes in specific immunodeficiencies have been identified. Examples include enteric cytopathic human orphan (ECHO) virus encephalitis in agammaglobulinemia, and meningococcal meningitis in C6 deficiency. Infections can also be induced by live vaccines given in immunodeficiency (e.g., paralytic polio in agammaglobulinemia.) Unusual infectious syndromes will be illustrated including parainfluenza infection in severe combined and immunodeficiency, Legionella pneumonia in chronic granulomatous disease, and Cryptosporidium infection in hyper-IgM immunodeficiency.

Antibody Formation↗
PubMed1985

Cystic degeneration of thymic Hodgkin's disease following radiation therapy.

A case of thymic Hodgkin's disease presenting with an anterior mediastinal mass is reported. The mass progressively expanded in size on plain chest radiography during and following a mantle radiation therapy. A repeat computed tomographic (CT) scan of the chest in this patient revealed a cystic component to the mass, and thin-needle aspiration of the cyst led to a shrinkage of the mass. An experience in this case and review of literature suggest Hodgkin's disease involving the thymus gland frequently predisposes to cystic degeneration especially following radiotherapy, leaving a stable or progressively enlarging residual mass. A precise diagnosis of such a progressively expanding mass despite the adequate radiation therapy is crucial. CT scan of the chest in such cases and a thin-needle aspiration of the cystic mass offer precise diagnosis and may obviate the need for an open thoracotomy procedure.

Adult↗
PubMed1985

Effects of physical fitness on expiratory airflow in exercising asthmatic people.

Maximal expiratory flow-volume maneuvers were performed by self-trained (FIT) and sedentary (UNFIT) asthmatic subjects. Both groups had similar pre-exercise pulmonary function limitations and attained the same exercising heart rate. The FIT group, however, exercised significantly longer than the UNFIT group. Although expiratory airflow increased in both groups during exercise, the FIT group had significantly larger airflow increases than the UNFIT group and maintained them throughout the exercise. In contrast, the UNFIT group's airflow decreased prior to the end of exercise. Tidal volume (VT) expiratory curves surpassed pre-exercise maximum expiratory flow-volume (MEFV) envelopes in subjects whose tidal volume was greater than 55% of vital capacity, the majority of whom were FIT subjects. In no case, however, did the VT curve exceed the enhanced exercise MEFV curve. The increase in airflow reserve during exercise helps to explain why asthmatic athletes, despite their significantly impaired pulmonary function, can compete successfully in sports making high aerobic demands.

Adult↗
PubMed1985

Temporal pulmonary function changes in cervical cord injury.

Temporal changes in pulmonary function (PF) in subjects with complete cervical cord transection occur in two stages. The first, extending from the acute to post-acute periods, is characterized by relatively rapid increases in the following: vital, inspiratory, and total lung capacities (VC, IC, and TLC, respectively), and inspiratory and expiratory airflows coupled with decreases in functional residual capacity (FRC). Second stage changes--from the post-acute period on--are more gradual, with both VC increase and FRC decrease continuing while TLC and ventilatory indices remain unchanged. The initial stage appears to be caused in part by functional respiratory muscle return coincident with resolution of inflammation and edema above the injury level. Altered respiratory mechanics also contribute to these early changes and the continuing later changes. Mechanical changes in the lung are probably both decreased compliance (which decreases FRC) and increased airway resistance (which diminishes airflow). Chest wall changes, resulting from returning spinal cord reflexes, affect PF via: (1) increased rib cage stability, leading to a more effective transduction of diaphragmatic displacement into lung volume, and (2) abdominal and expiratory intercostal spasticity, which could limit maximum inspiration. The net effect of these changes, however, may eventually lead to chronic hypoventilation.

Adolescent↗
PubMed1985

Chest physical therapy: comparative efficacy of preoperative and postoperative in the elderly.

Although chest physical therapy (PT) immediately after surgery lowers the risk of postoperative pulmonary complications, several reports indicate preoperative chest PT results in further improvement. This study compares the effects of initiating chest PT either before and/or after chest surgery in patients over age 65. We studied two groups: 130 patients (the PRE group) undergoing both pre- and postoperative therapy and 150 patients (the POST group) undergoing only postoperative therapy, dividing them into four surgical subgroups: lung, cardiac and other thoracic surgery, upper abdominal, and lower abdominal (considered low risk compared with the other three). Overall complication rates and atelectasis rates were significantly lower in the PRE high-risk subgroups. PRE and POST pneumonia rates, however, were statistically equivalent in all surgical subgroups. Since the low rate of pulmonary complications for PRE-group patients undergoing thoracic or upper abdominal procedures is comparable to that for PRE-group therapy in much younger populations, advanced age alone does not appear to be a significant risk factor. The lack of effect on incidence of pneumonia indicates that preoperative chest PT only counters the altered pulmonary mechanics responsible for atelectasis, but has no effect on pulmonary complications due to infection.

Abdomen↗
PubMed1984

Injury to the hand with metallic mercury.

Two cases of a rare injury to the hand with metallic mercury are presented. The toxic effects of this mercurial form are described and early surgical removal by suction tube is recommended.

Adult↗
PubMed1984

The effect of unemployment duration on national suicide rates: a time series analysis, 1948-1982.

The relationship between unemployment and suicide in the United States is examined. Data for the period 1948 to 1978, primarily from the U.S. Public Health Service, are used to examine the effect of the duration of unemployment on suicide. "The results of a Cochrane-Orcutt iterative regression analysis indicate that the greater the duration of unemployment the greater the suicide rate. Using ex post forecasting techniques it is estimated that increases in unemployment during the Reagan administration have been associated with at least 929 additional deaths from suicide."

Americas↗
PubMed1984

Accuracy of pulmonary function tests in predicting exercise tolerance in chronic obstructive pulmonary disease.

The ability of pulmonary function tests (PFTs) to predict exercise capacity was investigated by using linear regression analysis to quantify the relationships between: (1) maximum oxygen consumption during treadmill exercise and PFT parameters; and (2) total external work performed during treadmill exercise and PFT parameters. In a group containing 11 healthy subjects, nine with mild/moderate chronic obstructive pulmonary disease (COPD) and ten with severe COPD, both maximum oxygen consumption (measured directly) and total external work (calculated indirectly from the sum of its horizontal and vertical components) correlated most strongly with indices of expiratory airflow (FEV1, FEF25-75%), less strongly with indices of ventilatory output (MVV) and resting levels of oxygen (PO2, SaO2), and weakly with indices of hyperinflation (FRC) and carbon dioxide retention (PCO2). Thus, FEV1, accounting for 56 percent and 60 percent of the observed variation in oxygen consumption and external work, respectively, can predict exercise tolerance from PFT measurements with some accuracy. If a more accurate evaluation is required, exercise testing should be prescribed.

Adolescent↗
PubMed1983

Ventilatory adjustments during sustained mechanical loading in conscious humans.

Ventilatory responses to inspiratory elastic and resistive loads of 67 men were analyzed. During the 1st, 5th, and 10th consecutively loaded breaths 1) individual responses ranged from a rapid-shallow to a slow-deep breathing pattern; 2) strong tidal volume (VT) defenders employed longer inspirations than did weak VT defenders; and 3) individual frequency responses were mediated by changes in inspiratory and/or expiratory timing. Thus the group response was qualitatively similar on the 1st, 5th, and 10th loaded breaths. Quantitatively, however, the group's mean minute ventilation increased throughout each episode owing to progressively larger tidal volumes coupled with equal breathing frequencies. During elastic loading this amplified VT defense was achieved by stronger inspirations with no systematic changes in timing, whereas during resistive loading it was achieved both by stronger and longer inspirations. Inspiring 5% CO2 induced a degree of hypercapnia exceeding that accompanying mechanical loading and yet elicited a comparatively modest enhancement of respiratory output. These findings suggest that in conscious humans 1) repeated mechanical loading activates neural load-compensating mechanisms; 2) the range of these neural adjustments varies with both load size and type; and 3) the stimulus to initiate this behavior is largely nonchemical.

Adolescent↗