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Biomedical subjects

F Haas

Publications and source records attributed to F Haas.

At least 55 records · Page 3Linked to original sources
PubMed1995

Restrictive lung disease following treatment for malignant brain tumors: a potential late effect of craniospinal irradiation.

PURPOSE: To examine the effects of lomustine (CCNU), a commonly used nitrosourea, and craniospinal radiation therapy on the subsequent development of restrictive lung disease (RLD) following treatment for malignant brain tumors. PATIENTS AND METHODS: Pulmonary function testing with measurement of lung volume, spirometry, and diffusion capacity was performed in 28 patients who had received CCNU and/or radiation therapy as treatment for a malignant brain tumor. The median age at the time of treatment was 11.4 years (range, 3.9 to 36.7) and radiation therapy was completed 6 months to 11.6 years (median, 2.6 years) before testing. Patients were divided into four groups based on prior therapy. Group 1 received involved-field irradiation and a CCNU-containing chemotherapy regimen (n = 7); group 2, craniospinal irradiation with a boost to the primary tumor site and a CCNU-containing chemotherapy regimen (n = 6); group 3, craniospinal irradiation with a boost to the primary tumor site and a non-CCNU-containing chemotherapy regimen (n = 7); and group 4, craniospinal irradiation with a boost to the primary tumor site without chemotherapy (n = 8). RESULTS: Fourteen patients (50%) had findings consistent with RLD. One of seven patients (14.3%) who received CCNU without spinal irradiation had RLD, whereas 13 of 21 (61.9%) who received spinal irradiation with or without CCNU had RLD (P = .038), including four of eight patients treated with craniospinal irradiation alone. Logistic regression analysis showed that only spinal irradiation was a significant predictor for RLD. Patients who received spinal irradiation were 4.3 times more likely to have RLD than those who did not receive spinal irradiation. CONCLUSION: Spinal irradiation may be a risk factor for the development of RLD.

Adolescent↗
PubMed1995

Effect of distractive auditory stimuli on exercise tolerance in patients with COPD.

We tested the hypothesis that a distractive stimulus, such as music, introduced during exercise can reduce perception of respiratory effort at any given level of exercise, whereas sensory deprivation increases effort perception. Thirty-six patients with moderate COPD participated in four sessions of symptom-limited exercise. The first session familiarized the subject with the protocol. The other sessions were performed under partial visual isolation while listening to music (M), or to grey noise (GN), or in silence (SIL), presented in randomized order. Subjects graded their respiratory effort using the Borg rating of perceived exertion (RPE) scale. Total exercise time (EXT) and external work (WT) were objective indices of exercise tolerance. EXT was 22% longer with M than with either GN or SIL (p < 0.001), and WT was 44% and 53% greater with M than with GN or SIL, respectively (p < 0.001). These increases occurred at a heart rate that was only a few beats higher than during GN or SIL (104 +/- 3 bpm for M and 101 +/- 3 bpm for GN and SIL), a minimal difference that was statistically significant (p < 0.001). At every level of exercise, perceived exertion with M was lower than for either GN or SIL (p < 0.001). Although the respective RPE was higher for SIL than for GN (p < 0.01) at every level of exercise, WT and EXT were no different. These data indicate that perceived effort can be significantly influenced by external factors. This in turn suggests that the use of distractive stimuli during exercise training programs with patients with COPD may significantly decrease perceived symptoms of respiratory discomfort, thus allowing the patient to exercise to a higher intensity, and potentially achieving more effective exercise reconditioning training.

Acoustic Stimulation↗
PubMed1994

Discrimination of transiently applied mechanical loads: breathing vs. pulling.

Two groups of 24 subjects each attempted to discriminate between large elastic and resistive loads during 50 randomized presentations of each load. Breathers inspired from the loads through a J valve, whereas pullers reciprocally stroked the plunger of a 2-liter syringe connected to the J valve. A range of load durations was obtained in each subject by prematurely unloading approximately one-half of the trials at graded times from their onset. Breathers produced random discrimination scores [50.8 +/- 2.5% (SE) correct] when loaded inspirations were shorter than unloaded inspirations [trials in which both loads induced equal airway pressure (and probably respiratory muscle tension) waveforms] and nonrandom discrimination scores (65.7 +/- 2.8% correct) when loaded inspirations were longer than unloaded inspirations (trials in which both loads induced different waveforms). In contrast, pullers produced nonrandom discrimination scores (62.2 +/- 2.9% correct) when loaded airflow durations were shorter than unloaded inspirations [trials in which both loads induced equal line pressure (and therefore limb muscle tension) waveforms]. Supplemental audio feedback related to instantaneous airflow (an expression of movement) improved load perception in breathers (to 64.2 +/- 3.0% correct; P < 0.01), indicating that airflow feedback introduced load-specific information that was lacking during breathing but redundant during pulling. In support of this hypothesis, airflow feedback by itself enabled a third group of listeners to identify load type with equal accuracy as pullers but with greater accuracy than breathers. These findings suggest that 1) uniformed subjects rely heavily on feedback from airway pressure and/or muscle tension receptors to perceive added loads to breathing and 2) limb mechanoreceptors provide a more sensitive appreciation of movement than do respiratory mechanoreceptors.

Acoustic Stimulation↗
PubMed1994

In the patient's best interests? Dehydration in dying patients.

1. Little is known about the physiological effects of dehydration in terminally ill patients. 2. Terminally ill patients in hospices are not usually given IV infusions. 3. Dying patients not given artificial hydration are less likely to need suction. 4. Hydrating dying patients may add to their distress.

Ethics, Nursing↗
PubMed1993

Use of maximum expiratory flow-volume curve parameters in the assessment of exercise-induced bronchospasm.

Exercise-induced bronchospasm (EIB) is often inferred from the reduction after exercise in one arbitrarily selected value derived from the maximum expiratory flow-volume (MEFV) curve (eg, FEV1) on a single test; however, patients with symptoms of EIB not meeting these criteria may risk being undiagnosed. To assess the ability of repeated tests using additional MEFV parameters in identifying EIB-prone patients, we investigated the effects of exercise provocation on the MEFV curve on two separate occasions. Of 95 patients with symptoms of EIB, 61 had reproducible exercise-induced changes (< 10 percent intraresponse variation), falling into four patterns: 27 (44 percent) had significantly reduced VC and airflow throughout the MEFV curve; 18 (30 percent) had unchanged VC but decreased airflow throughout the curve; 11 (18 percent) had reduced airflow above 50 percent VC but not below 50 percent VC; and 5 (8 percent) had significant reductions in airflow only at 50 percent VC or below. Of the other 34 subjects, 18 had no apparent response, and 16 responded on only one occasion, making objective assessment of these patients' EIB equivocal. We conclude that for a given individual, failure to meet arbitrary criteria does not rule out EIB. Additionally, a more subjective approach that integrates, among other factors, all routine MEFV curve parameters taken from multiple tests with clinical symptoms and history provide a more accurate assessment of EIB.

Adolescent↗
PubMed1992

Serial sectioning of insects with hard exoskeleton by dissolution of the exocuticle.

The method reported here was designed to produce paraffin serial sections as thin as 5 microns of insects or other arthropods with a hard cuticle. Heads and abdomens of Apis mellifera, Eristalomyia tenax and Tenebrio molitor were fixed with Schaffer's liquid, dehydrate with 80% ethanol, 90% ethanol, two changes of 100% isopropanol (2 hr each) and 12 hr in a 1:1 mixture of paraffin (58 C melting point) at 60 C. They were molded in paraffin after 12 hr of infiltration under a partial vacuum at 60 C. Large body openings of objects were sealed with paraffin to prevent infiltration of solvents. Thereafter, the outer paraffin was removed manually and with xylene (15 min); the cuticle was rehydrated with 100% isopropanol and 100% ethanol (15 min each). The objects were then treated with Sputofluol (Merck; a mixture of NaOH and NaClO) until they became white or their colorless endocuticle was stainable with aniline blue WS (C.I. 42755) after rinsing in a 50% acetic acid solution (v/v). They were then dehydrated with 100% ethanol and 100% isopropanol (15 min each) and subsequently re-embedded in paraffin. They were molded, sectioned, stained and mounted as usual.

Animals↗
PubMed1992

[Polyposis of the nasal sinuses. Epidemiology and clinical aspects of 350 cases. Treatment and results with a follow-up over 5 years on 93 cases].

The authors report a series of 350 patients referred for clinical investigation of nasal polyps between 1980 and 1990. 93 patients were followed for more than 5 years. Allergy to inhalants was rarely found (2.8%). Detailed study of past rhinosinusal and bronchial symptoms often revealed a history of vasomotor rhinitis (nasal hyperreactivity HRN) preceding the nasal polyposis by a mean interval of 8 years. The ratio non-allergic vasomotor rhinitis/nasal polyps was 4.31 in women (41.4% of the patients) and 1.74 in men (58.6% of the patients). Treatment is usually based on the use of local corticosteroids. However, because of the variable clinical pattern of nasal polyposis treatment may be medical alone or both medical and surgical, and always requires a long clinical follow-up. Intolerance to aspirin is a factor of poor prognosis. A 15% failure rate was noted among patients intolerant to aspirin.

Adolescent↗
PubMed1991

Global and regional ventricular function following intracoronary application of papaverine.

Intracoronary injection of papaverine is used to determine coronary flow reserve in patients. The present study was to investigate the effect of papaverine on the performance of myocardium with reduced flow reserve. In nine anaesthetized open-chest dogs a bypass from the aorta to the left circumflex coronary artery (LCX) was established. Left ventricular end-diastolic and aortic pressure, dP/dt, stroke volume, LCX blood flow, and ECG were monitored. The performance of a segment of subendocardial wall supplied by the LCX was assessed by sonomicrometry. Peak reactive hyperaemia after 15s bypass occlusion was 1.44 +/- 0.09 times the baseline flow (41 ml/min), indicating reduced coronary flow reserve. Papaverine was injected into the bypass (0.3, 0.6, 1.2, 2.5, 5.0 mg/ml, 1 ml in 15s). The maximum LCX flow following PAPA 0.3 mg was comparable to peak reactive hyperaemia, but 10-15% higher after injection of 0.6-5.0 mg papaverine. Systolic shortening of the myocardium (control: 17.5% of end-diastolic length) became reduced in a dose-dependent fashion (5-25%) for about 1 min following papaverine injection. Stroke volume (control: 0.94 +/- 0.12 ml/kg) was reduced by about 8%, left ventricular end-diastolic pressure (control: 6.2 +/- 0.8 mmHg) increased by 15%, and dP/dtmin (control: 1850 +/- 150 mmHg/s) was curtailed by 15-25%. The ECG showed a transient T inversion and S-T depression following papaverine administration and in one experiment ventricular fibrillation occurred after the injection of 2.5 mg papaverine. The observed effects of intracoronary papaverine are consistent with the theory of transient subendocardial ischaemia arising from a redistribution of blood flow from the subendocardial to the subepicardial layers, because of greater vasodilatory capacity in the latter than in the former.

Animals↗
PubMed1991

Effect of the 'specific bradycardic agent' alinidine on the function of ischemic myocardium.

In patients with coronary artery disease, the reduction of heart rate (HR) by beta-blockers can further impair myocardial function by reducing the contractility and coronary perfusion. This is possibly not the case for "specific bradycardic agents" like alinidine (ALI). The effect of ALI on ischemic myocardium, therefore, was studied in anesthetized open-chest dogs measuring left ventricular end-diastolic pressure (LVedP), dP/dt, aortic pressure (AoP) by catheter tip manometers, coronary blood flow (Q) electromagnetically, end-diastolic length (edL) and systolic shortening (sdL in %edL) of ischemic (RISC) and non-ischemic (NISC) wall segments by sonomicrometry. Group A (n = 11): Left coronary artery constriction to reduce Q (-53%) and poststenotic sdL (-54%), then i.v. injection of ALI (0.25 + 0.25 + 0.5 + 1.0 mg/kg), thereafter atrial pacing at HR before ALI. Group B (n = 9): Installation of an aorto-coronary bypass, pump-perfused at 50% of free flow, infusion of ALI into the bypass. The results showed that ALI iv dose-dependently reduced HR from 135/min to 90/min, LVedP rose from 8.6 to 10.0 mmHg and NISC-edL from 14.1 to 14.6 mm indicating increased ventricular filling. Non-ischemic systolic shortening did not change. Ischemic systolic shortening was improved from 9.2% to 17.5%, which was not due to an increase in RISC-edL (14.8 versus 14.7 mm), enhanced RISC-Q (13 versus 12 ml/min), reduced AoP (86 versus 84 mmHg) or change in inotropy (dP/dtmax: 2290 versus 2240 mmhg/s), but the increase in RISC-sdl correlated closely (r greater than 0.85) to the reduction in HR (oxygen-demand).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effect of milk ingestion on pulmonary function in healthy and asthmatic subjects.

Since Maimonides, it has been common in folk medicine to proscribe milk for asthmatics because its putative stimulation of mucus production can exacerbate asthma symptoms. A literature review, however, failed to reveal any data supporting this notion. We, therefore, compared the effects of ingesting 16 oz. of whole milk (16 g lipid), skim milk (2 g lipid), and water (each on a separate day) on: (1) forced expiratory volume in 1 second (FEV1), (2) forced expiratory flow at 50% of vital capacity (V50), and (3) pulmonary diffusing capacity (DLCO) in 11 asthmatic and 10 nonasthmatic subjects. Measurements were taken at 30 minute intervals for 3 hours. The two milk types did not significantly change FEV1 or V50 in either group, indicating that the amount ingested did not change airway resistance sufficiently to alter airflow parameters. In the asthmatic group, however, DLCO decreased progressively over the 3 hours by 6.8 +/- 1.4% (mean +/- SE) per hour after whole milk (maximum reduction = 21 +/- 1.4%) but not after water or skim milk. In the nonasthmatic group, no significant effects were observed on DLCO after any of the liquids. These data suggest that milk lipids can disturb gas exchange in asthmatic patients.

Adult↗
PubMed1990

The influence of coronary angiography and angioplasty on parameters of hemostasis and fibrinolysis.

The influence of invasive investigations on parameters of hemostasis and fibrinolysis is generally unknown, although this has consequences for the design of prospective studies on the association between those parameters and regression or progression of atherosclerosis. We therefore determined hemostatic and fibrinolytic factors in 12 patients who were admitted to the hospital for coronary angiography (CAG; n = 5) or percutaneous transluminal coronary angioplasty (PTCA; n = 7). Blood samples were drawn under basal circumstances on the day before, the day of and the day after CAG or PTCA. Significant changes occur in the concentrations of platelets and white blood cells, hematocrit (Ht), von Willebrand factor antigen (vWF:ag), antithrombin III-activity (AT III-ag), antithrombin III-antigen (AT III-ant), fibrinogen, plasminogen, alpha2-antiplasmin (alpha2-AP), histidine-rich glycoprotein (HRG), and plasminogen activator inhibitor (PAI)-activity. Mean values of beta-thromboglobulin, platelet factor 4, factor VIII:C, tissue-type plasminogen activator activity (t-PA act) and euglobulin clot lysis time (ECLT) do not differ significantly. After correction for Ht, no significant differences exist between the day before and the day of the procedure; but on the day after CAG and PTCA significant differences occur in white blood cells, factor VIII:C, AT III-ag, alpha2-AP and PAI-act. It is concluded that principally blood samples for investigations on fibrinolysis may be taken on the day before or the day of CAG or PTCA without a loss of quality, if the values are corrected for Ht. Samples taken on the day after the procedure are not useful for such purposes.

Angina Pectoris↗
PubMed1990

Complications after cardiac operations in patients with severe pulmonary impairment.

The postoperative courses of 39 patients with severe lung disease (31 with obstructive disease and 8 restrictive) who underwent a cardiac operation were retrospectively reviewed. The stay in the intensive care unit of the study group was 7.9 +/- 10.3 days (mean +/- standard deviation) compared with 2.4 +/- 3.9 days for the control group (100 patients with less impaired pulmonary function) (p less than 0.001). The study group also had a greater number of valve replacements than did the control group (p less than 0.01). Patients with obstructive disease had more respiratory complications than did patients with restrictive disease (p less than 0.05). There were 21 cases of atelectasis. Effusions were noted in 11 patients. Ten patients had bronchospasm. Bronchial secretions were a major problem in 6 patients. Pneumonia developed in 4 patients, and pneumothorax occurred in 3 others. The two in-hospital deaths were not directly related to pulmonary complications. Our findings indicate that (1) patients with severe lung impairment generally do well after a cardiac operation but have more postoperative pulmonary complications than patients with less impairment; (2) patients with restrictive pulmonary disease appear to fare better than those with obstructive disease; (3) pulmonary function tests can alert the clinician to the possible risk of postoperative complications, but they cannot, by themselves, be used to exclude patients from operation; and (4) patients with severe pulmonary impairment facing valve replacement are at greater risk of pulmonary complications than patients having other types of cardiac surgical intervention.

Bronchial Spasm↗
PubMed1990

Pentoxifylline improves pulmonary gas exchange.

Pentoxifylline is a xanthine derivative with hemorrheologic and vascular properties that may improve gas exchange in patients with chronic obstructive pulmonary disease (COPD). We tested this hypothesis in 12 patients with COPD (mean FEV1 = 40 percent predicted; mean DCO, 8.6 ml/min/mm Hg) randomly divided into a treatment and control group and six healthy volunteers. Following establishment of baseline DCO and maximum expiratory flow volume (MEFV) curve values, each subject in the treatment and healthy groups took 400 mg of pentoxifylline three times a day for 12 weeks. Weekly DCO and MEFV curves were measured before treadmill exercise in both COPD groups and before and after exercise in the healthy group. The MEFV curve parameters from the final three weeks of therapy did not differ significantly from baseline values. During this time, however, the treatment COPD group's resting DCO rose by 8.2 +/- 2.4 percent over baseline level (p less than 0.01). Treadmill walk time increased from 17.7 +/- 2.9 minutes to 23.2 +/- 2.9 minutes (p less than 0.02). This was accompanied by improved exercise oxygen saturation measured by oximetry (SoxiO2). Premedication SoxiO2 fell from 92.8 +/- 1.2 percent to 88.6 +/- 2.5 percent during exercise, and from 94.4 +/- 1.1 percent to only 91.8 +/- 1.0 percent after 12 weeks of medication (p less than 0.05). No such improvement was noted in the control COPD group. Although the healthy group's resting SoxiO2 and DCO did not change during treatment, their exercise DCO increased significantly from 36.3 +/- 3.1 ml/min/mm Hg to 41.8 +/- 3.5 ml/min/mm Hg (p less than 0.001). These data demonstrate that pentoxifylline improves gas exchange, possibly by increasing cardiac output, and/or by raising mixed venous PO2, and/or by improving blood flow to underperfused alveoli.

Adult↗
PubMed1990

[Skull vault bone graft in augmentation septorhinoplasty].

We describe our technique of augmentation rhinoplasty with bone grafting. Degloving is used as the surgical access in collapsed noses, and midcolumellar incision allows further buildup of the nasal contour. A V cutting is made on the dorsum to receive the graft. A split skull graft is taken with a drill and an osteotome. The sculpted bone implant is maintained in position with a miniaturized screw. We compare various bone grafts and types of surgical access.

Bone Transplantation↗