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Biomedical subjects

M Schatz

Publications and source records attributed to M Schatz.

At least 73 records · Page 4Linked to original sources
PubMed1985

[Experimental studies of the scatter behavior of fast electrons in the use of electron applicators in radiotherapy].

When using high energy electrons in radiotherapy, there is frequently undesirable electron scatter, which is derived from the applicators used to delimit the field. In order to improve our understanding of the factors which influence scatter, this was studied using fast electrons and a variety of materials to reduce this scatter. The geometry and angulation of the scattering plate and the electron energies were varied during these experiments.

Electrons↗
PubMed1984

Skin testing and incremental challenge in the evaluation of adverse reactions to local anesthetics.

True allergic reactions to local anesthetics (LAs) probably make up no more than 1% of all adverse LA reactions. A diagnosis of true potential allergic reactivity is made difficult because (1) the history of the prior reaction may be vague or equivocal and (2) the lack of identification of the actual specific LA hapten-carrier complex limits the potential usefulness of immunologic tests. Nonetheless, since avoidance of LAs may be associated with substantial increased pain or increased risk and because true allergic reactions are rare, investigators and clinicians have used skin testing, incremental challenge, or both as a means of identifying a safe LA for a patient with a history of a prior adverse reaction. Review of the literature dealing with LA skin testing and incremental challenge suggests the following: (1) Skin testing with LAs may correlate with a history of an adverse reaction but may produce systemic adverse reactions, especially with undiluted drug. (2) Although false positive skin tests have been reported, most skin-tested patients who subsequently tolerate an LA have a negative skin test to that drug, and false negative skin tests have not been clearly documented. (3) Incremental challenge beginning with diluted LA is a safe and effective means of identifying a drug that a patient with a history of a prior adverse reaction can tolerate. (4) Current concepts of non-cross-reacting LA groups may be useful in the choice of a drug for use in skin testing and incremental challenge. (5) Preservatives in LAs may account for some but probably not the majority of adverse reactions to LAs. On the basis of this literature review, a practical protocol including dilutional skin testing and incremental challenge is presented for use in evaluating patients with prior adverse reactions to LAs.

Anesthetics, Local↗
PubMed1984

Aspirin-sensitive rhinosinusitis asthma: a double-blind crossover study of treatment with aspirin.

Twenty-five ASA-sensitive patients with rhinosinusitis asthma underwent oral ASA challenges followed by desensitization to the adverse respiratory effects of ASA. We then compared the efficacy of continuous ASA treatment for their respiratory tract disease to that of a placebo treatment during a double-blind crossover study. For this group of 25 patients, there was significant improvement in nasal symptoms and a reduction in use of nasal beclomethasone during the months when they received ASA treatment. Lower respiratory tract symptoms, values of FEV1, and the use of antiasthmatic medications including prednisone were not significantly changed during ASA treatment. Desensitization to ASA followed by ASA treatment appears to significantly alleviate symptoms of rhinosinusitis. However, only half the patients experienced improvement in their asthma symptoms during ASA treatment.

Aspirin↗
PubMed1983

Aspirin-sensitive rhinosinusitis/asthma: spectrum of adverse reactions to aspirin.

In order to determine the types of respiratory responses observed during aspirin-induced reactions, 50 consecutive asthmatic patients with a history of aspirin sensitivity underwent prospective oral aspirin challenges between 1979 and 1981. Oral aspirin challenges produced 36 asthmatic responses (33 combined with rhinitis and three purely asthmatic) and six acute rhinoconjunctivitis responses (three combined with mild asthma and three purely rhinoconjunctivitis) but failed to stimulate any reaction in eight patients. The results produced by these challenges were then compared with results recorded during additional aspirin challenges in 28 of these patients, performed after the index challenge in 1979-1981 in 26 patients and in the case of two patients before 1979. The type of respiratory response to aspirin varied significantly in 11 (39%) of the 28 patients and included disappearance of aspirin reactivity in four patients.

Adolescent↗
PubMed1982

The eosinophil and the lung.

Current concepts regarding the morphology, constituents, distribution, and kinetics of the eosinophil allow an expanded understanding of the eosinophil's function in health and disease. In particular, certain eosinophil constituents may have beneficial effects (modulation of mast cell-dependent reactions and helminthotoxic properties), while others may produce detrimental effects (tissue destruction). Eosinophils may be clinically important in obstructive and infiltrative pulmonary diseases. In obstructive disease, a peripheral eosinophilia indicates reversibility, and the magnitude of the peripheral eosinophil count correlates with the severity of the reversible obstruction. Concerning infiltrative pulmonary disease, an updated classification of pulmonary infiltrates with eosinophilia, which is based on recognizable causes and syndromes, is presented, and allergic bronchopulmonary aspergillosis, chronic eosinophilic pneumonia, drug reactions, the hypereosinophilic syndrome, parasitic infestations, and the Churg-Strauss syndrome are specifically considered.

Eosinophilia↗
PubMed1982

Aspirin desensitization in aspirin-sensitive asthmatic patients: clinical manifestations and characterization of the refractory period.

Thirty aspirin-sensitive asthmatic patients underwent incremental, oral aspirin challenge until a "positive reaction" (delta FEV1 greater than or equal to 25%) occurred. After this reaction, aspirin was readministered in an attempt to achieve "desensitization." This was defined as the ability of the patient to ingest 650 mg of aspirin without experiencing upper or lower respiratory-tract symptoms or a decrease in lung function. To determine the "refractory period" following aspirin desensitization, patients were rechallenged after various intervals (days) without aspirin until a positive reaction recurred. All 30 aspirin-sensitive asthmatic patients were successfully desensitized to aspirin. Individual patient refractory periods ranged from less than 2 days to greater than 5 days, with most patients gradually returning to sensitivity between 2 to 4 days. Cross-densensitization with indomethacin and other nonsteroidal anti-inflammatory drugs was also demonstrated. These studies show that aspirin desensitization can be safely achieved in aspirin-sensitive asthmatic patients; however, this desensitization will gradually disappear over several days when additional aspirin is withheld.

Adolescent↗
PubMed1980

Efficacy of troleandomycin in outpatients with severe, corticosteroid-dependent asthma.

Sixteen severe, corticosteroid-dependent yet resistant outpatient asthmatics were treated with troleandomycin (TAO), a macrolide antibiotic, in an attempt to both induce a clinical remission and reduce methylprednisolone requirements. Within the first 2 wk of initiating TAO therapy, 50% of the patients experienced a greater than 20% increase in forced expiratory volume in 1 sec (FEV1) and 80% noted a greater than 20% increase in forced vital capacity between 25% and 75% (FVC 25%-75%). Maximal increases in FEV1 and FVC 25%-75% were noted in all patients within the first 6 wk on TAO and methylprednisolone. There was a concomitant clinical improvement in all patients. Corticosteroid-induced side effects, gastrointestinal tract discomfort, and elevated serum glutamic pyruvic transaminase (SGPT) were common yet generally transient during TAO and methylprednisolone therapy. After a 4- to 18-mo follow-up 15/16 patients were well-controlled on TAO and methylprednisolone. Methylprednisolone requirements were reduced at least four- to fivefold in most patients during TAO therapy. Normal morning serum cortisol levels were documented after varying intervals in most patients when both TAO (250 mg) and methylprednisolone (4 to 16 mg) could be reduced to alternate-day administration. Only one patient was forced to discontinue therapy due to side effects. The present study extends the effectiveness of TAO therapy to ambulatory asthmatics, establishes a clinical strategy that maximizes benefit/risk factors, and provides practical guidelines for the long-term use of TAO and methylprednisolone.

Adolescent↗
PubMed1980

Intranasal flunisolide in the treatment of perennial rhinitis: Correlation with immunologic parameters.

The effectiveness and safety of 200 micrograms/day of intranasal flunisolide in the treatment of perennial rhinitis was studied in 56 patients in a 6 wk double-blind parallel vehicle controlled clinical trial. In addition, patients failing to respond to placebo were entered into a 6 wk open trial with the active drug. Forty-six percent of the flunisolide-treated patients achieved total or substantial control of their nasal symptoms compared to 11% of the placebo-treated group in the double-blind study (p = 0.031). Eighty percent of patients achieved total or substantial control of their nasal symptoms in the 6 wk open study. No adverse effects attributable to flunisolide were observed. Parameters of IgE-mediated reactivity, including immediate-type skin test reactivity, total serum and nasal secretion IgE, specific serum and nasal secretion IgE, and nasal eosinophilia, were also assessed in these patients. Although benefit from flunisolide significantly correlated with all of these parameters except specific serum IgE, the absence of these findings did not preclude significant benefit from the drug. This study demonstrates the efficacy and safety of intranasal flunisolide in the treatment of perennial rhinitis, especially but not exclusively in those patients with evidence of IgE-mediated reactivity.

Administration, Intranasal↗