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Biomedical subjects

I Schwarz

Publications and source records attributed to I Schwarz.

At least 19 recordsLinked to original sources
PubMed2006

Solid-state characterization of non-stoichiometric hydrates of ester-type local anaesthetics. Part XI. Crystal polymorphism of local anaesthetic drugs.

Three structurally closely related local anaesthetic drugs, hydroxyprocaine hydrochloride (4-butylamino-2-hydroxybenzoic acid 2-dimethylaminoethyl ester hydrochloride, HPCHC), tetracaine hydrochloride (4-butylamino-2-hydroxybenzoic acid 2-dimethylaminoethyl ester hydrochloride, TCHC) and hydroxytetracaine hydrochloride (4-butylamino-2-hydroxybenzoic acid 2-dimethylaminoethyl ester hydrochloride, SLCHC) are found to form hydrated crystals. Those were characterized by thermal analysis (hot stage microscopy, differential scanning calorimetry, thermogravimetry), vibrational spectroscopic methods (FTIR-, FT-Raman-spectroscopy), powder X-ray diffractometry, solid-state NMR and water sorption/desorption analysis. The formation and the stability of the hydrated solid phases are evaluated by sorption isotherms derived from different sorption/desorption analytic methods. The three substances investigated show conformational polymorphism with the anhydrated phases including a high temperature form mod. I, which is highly hygroscopic and isostructural with the hydrate. The hydrated form is present in commercial products at various contents. These hemihydrates crystallize from water, whereas the anhydrates crystallize from all other tested organic solvents. Different methods of water sorption/desorption analysis indicate the formation of non-stoichiometric hydrates. Different methods of drying lead to the same results. Solid-state NMR spectra were used to obtain both structural and molecular level mobility information.

Adsorption↗
PubMed2006

Polymorphism and pseudopolymorphism of salicaine and salicaine hydrochloride crystal polymorphism of local anaesthetic drugs, part V.

The local anaesthetic drug salicaine hydrochloride (hydroxytetracaine hydrochloride, 4-butylamino-2-hydroxybenzoic acid 2-dimethylaminoethyl ester hydrochloride, SLCHC) and the free-base salicaine (SLC) were characterized by thermal analysis, vibrational and solid-state NMR-spectroscopy, X-ray powder diffraction, X-ray single crystal structure analysis, and water vapor sorption analysis. Additionally, the crystal structures of the anhydrate mod. II degrees (monoclinic, space group P2(1)/n), the hydrated mod. I (triclinic, space group P(bar)1), and of the free base (SLC) in the form of the hemihydrate (triclinic, space group P(bar)1 are discussed. Mod. II degrees of the polymorphic SLCHC is the thermodynamically stable form at room temperature and is present in commercial products mostly contaminated with a hydrated form that is isomorphic with mod. I. Mod. II degrees crystallizes from most organic solvents and from the melt below 110 degrees C. Mod. I crystallizes from the melt at temperatures above 110 degrees C, and additionally appears on dehydration of the hydrated mod. I. A third polymorph monotropically related to mod. II degrees was found by freeze-drying. The free-base SLC was found to crystallize from ethanol/water as a triclinic hemihydrate.

Absorption↗
PubMed2001

Freely accessible endoscope channels improve efficacy of cleaning.

BACKGROUND AND STUDY AIMS: Inadequate cleaning and disinfection of medical devices, including flexible endoscopes, can result in the transmission of micro-organisms to patients. The aim of this study was to investigate the influence of the design of medical devices on the efficacy of manual cleaning of endoscope channels. MATERIALS AND METHODS: The investigation was carried out using four endoscopes (two duodenoscopes and two gastroscopes). The air/water channels of one duodenoscope and one gastroscope were freely accessible and could be brushed. The instrumentation and the air/water channels were contaminated with blood containing Enterococcus faecium as a test organism. After manual cleaning of the channels by flushing and, where possible, brushing, the recovery rates for the test organism were studied. RESULTS: The comparable rates for recovery of the test organism after cleaning of the instrumentation channels proved that the method used was reproducible. With regard to the air/water channels, the rate of micro-organisms in the cleaning solution recovered after flushing alone was a maximum of 3 % relative to the rate detected after brushing and flushing. CONCLUSIONS: The data collected in the study show that only flushing channels that are not freely accessible resulted in significantly lower (P<0.001) recovery rates for the test organism. In practice, this means that contamination may remain in the channels, and it shows that the design of a medical device has an important influence on the reprocessing of reusable instruments such as flexible endoscopes.

Disinfection↗
PubMed2000

Physiologic fluctuations of serum estradiol levels influence biochemical markers of bone resorption in young women.

We investigated the effect of physiologic variations in sex hormone levels during the menstrual cycle on biomarkers of bone turnover. Blood and 24-h and fasting urine samples were obtained in nine women (age, 25.1+/-3.0 yr) with regular menstrual cycles during the early follicular period (t1), 3 days before ovulation (t2), 3 days after ovulation (t3), at the midluteal period (t4) and again during the early follicular period of the next cycle (t5). All subjects had a calcium intake covering current dietary recommendations (above 1,000 mg/day, standardized food record). Serum calcium, phosphorus, calcitriol, 24-h and 2-h fasting urinary calcium, and phosphorus excretion remained constant during the menstrual cycle. Serum 25-hydroxyvitamin D3 levels decreased slightly from the beginning until the end of the study (P<0.05), indicating low cutaneous vitamin D synthesis during wintertime. The serum levels of sex hormones showed typical monthly variations, with the lowest estradiol (E2) levels at t1 and t5. Fasting 2-h pyridinoline (Pyd) concentrations (a marker of bone resorption) fell from t1 to t3 and rose again at t5 (P<0.01). Similar variations were observed for the resorption marker deoxypyridinoline (Dpd; P<0.05). The amplitude of the two biomarkers was 32% and 33%, respectively. The serum levels of the carboxyterminal propeptide of type I collagen (a marker of bone formation) showed an inverse cyclic pattern, as compared with the pyridinium cross-links. Low concentrations were observed at t1; a rise occurred until t3 and was followed by a decrease until t5 (P<0.05). A similar cyclic pattern was observed for serum PTH levels, with the highest concentrations at t3 (P<0.05). Dpd and Pyd values were significantly correlated with serum E2 levels (r = 0.52; P<0.0001 and r = 0.50; P<0.001, respectively). Neither progesterone nor LH nor FSH was correlated with Pyd or Dpd levels. The data suggest that normal menstrual cycling in young women is associated with monthly fluctuations in bone turnover. This physiological effect of the menstrual cycle is most probably related to variations in serum E2 concentrations.

Adult↗
PubMed1999

Regulation of CD97 protein in thyroid carcinoma.

CD97 is a dimeric glycoprotein belonging to the secretin receptor superfamily and is abundantly expressed in cells of hematopoietic origin. The aim of this study was to analyze the expression of the CD97 protein in thyroid carcinomas and the role of all-trans-retinoic acid (RA) in the regulation of CD97 protein in monolayer culture of the human follicular thyroid carcinoma cell line FTC-133. In normal thyroid tissue, no immunoreactivity of CD97 could be found, whereas in differentiated thyroid carcinomas, CD97 expression was either lacking or low. Undifferentiated anaplastic thyroid carcinomas revealed high CD97 expression. The expression of CD97 protein seems to be correlated to the postoperative histopathological classification staging. Approximately 50% of FTC-133 cells expressed the CD97 protein under basal culture conditions. No differences were found in the number of CD97-positive cells after TSH, forskolin, and insulin treatment compared to control values. Epidermal growth factor treatment led to an increase in CD97 immunostaining (up to 90%), whereas phorbol 12-myristate 13-acetate slightly decreased the immunoreactivity of CD97 (from 50% to 30%). Under basal conditions, RA treatment for 72 h led to a decrease in total cell number by 33% and in CD97-positive cells from 50% to 30%. TSH, forskolin, phorbol 12-myristate 13-acetate, and insulin showed no effect after 72-h pretreatment with RA, whereas epidermal growth factor treatment led to a slight increase in the number of the CD97-positive cells (from 30% to 40%) compared to the control value. These data suggest that CD97 expression may play an important role in the dedifferentiation of thyroid tumors, and RA might interfere with this process in thyroid carcinoma by suppressing the dedifferentiation marker CD97.

Adult↗
PubMed1994

The effect of exercise on basophil histamine release in patients with bronchial asthma.

There is increasing evidence for the role of basophils in allergic bronchial asthma. We studied the potential role of basophils in the pathogenesis of post-exercise-induced bronchoconstriction by measuring the histamine release from basophils both spontaneously and following ConA, FMLP, anti-IgE and TPA treatment. Two groups of patients with allergic asthma were studied: group I consisted of 8 patients with an exercise-induced fall in FEV1 of 20% or more, and group II had 7 patients with bronchial asthma who had less than a 5% fall in FEV1 following exercise. The mean spontaneous histamine release (SHR%) from basophils for group I was significantly larger than that of group II both before as well as at 5-10 and 60 min following exercise. The SHR% at baseline was 25 +/- 10 in group I (mean +/- SD) and 15 +/- 5 in group II (mean +/- SD). At 5-10 min following exercise it was 24 +/- 6 in group I and 11 +/- 2 in group II, while at 60 min following exercise it was 24 +/- 6 in group I and 17 +/- 2 in group II. There was no significant difference between the two groups in the effect of ConA, FMLP, anti-IgE or TPA treatment on basophil histamine release. The enhanced bronchoconstriction by exercise did not affect histamine release either spontaneously or following those 4 stimuli. It was concluded that, although patients with exercise-induced asthma have a greater degree of spontaneous histamine release, this is not affected by induced bronchoconstriction, a finding which does not support a role for basophils in exercise-induced asthma.

Adolescent↗
PubMed1993

[Regional cytostatic perfusion of the extremities in patients with malignant melanoma and soft tissue sarcoma--therapeutic applications and results].

94 patients with malignant melanoma or soft tissue sarcoma of the extremities were submitted to isolated cytostatic limb perfusion. With palliative indication for treatment of malignant melanoma, the 5 year survival rate was 25% after perfusion with methotrexate and 50% after perfusion with melphalan. The adjuvant perfusion showed very good results, too. Furthermore, the authors report on their first experiences in regional cytostatic perfusion of soft tissue sarcoma and bone sarcoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Sensual-imaginative training methods for students of medicine.

A specific lecture course for medical students is described which elucidates the interactions of the role of initial doctor-patient and student-patient interviews in cases where psychotherapy is to be applied to the treatment of psychosomatic illnesses. The ultimate goal of this living-learning-based teaching system is to allow the student to experience and evolve a concept of the role of the doctor with respect to the patient. The teaching system is structured in the frame of Balint groups [Balint, 1975]. Emphasis is placed on describing how medical students undergo an emotional awareness training program, to enable them to function and develop their new role as a doctor with reduced fear. We report about a specific setting in Balint groups, in which mood, physical sensation and fantasy work are made into the center point of the group process.

Curriculum↗
PubMed1989

Office profile.

A national study was conducted by the American Dental Hygienists' Association (ADHA) in 1986, to examine several variables related to dental hygiene practice. Questionnaires were sent to both ADHA members and nonmembers with a response rate of 49.6%. The 4,013 hygienists who responded to this survey answered 80 questions, six of which related to office profile and are reported in this paper. The responses concerning state of practice, community size, practice setting, number of office personnel, number of hours worked, and age characteristics of patients are included. Results indicate that most hygienists work primarily in traditional dental practices, live in metropolitan areas, and are most likely to treat a majority of patients between the ages of 19 and 44. Seventy-one percent of the hygienists work 20 hours or more per week and the mean number of hours worked per week is 32. This indicates that most dental hygiene practitioners work full-time.

Adolescent↗
PubMed1989

[Effect of heavy metal ions on male fertility].

In this study 67 workmen exposed to ions of heavy metals have been investigated because of their fertility. Concentrations of the noxious substances and their metabolites in blood and urine have been estimated and spermiograms were performed. The investigations demonstrated that a correlation exists between the concentrations of noxious substances in the place of employment, in the blood, and in the ejaculate, besides of zinc. An increased number of pathological spermiograms could be established especially in cases with an exceed of maximum permitted concentrations in the place of employment.

Air Pollutants, Occupational↗
PubMed1984

Three perspectives on the speech of children with Down's syndrome.

The present research describes aspects of the phonologies of three children with Down's syndrome, aged 3;4, 3;6, and 4;6. The results of the study are presented from three perspectives. First, each child's consonant productions are sifted to determine what sounds the child uses to distinguish between different meanings. Second, each child's consonant productions are arranged to show what sounds the child has learned to pronounce correctly. Third, each child's consonant productions are analyzed to ascertain what phonologic processes cause the child to pronounce certain sounds incorrectly. The sum of the three perspectives is intended to provide information that will be useful to both clinicians and researchers.

Child, Preschool↗
PubMed1977

An accurate determination of human growth hormone content in different pituitary extracts, using a radioimmunoassay with polyacrylamide gel electrophoresis as a bound-free separation system.

Human growth hormone was extrated and purified according to the method of Roos et al. (Roos, P., Fevold, H.R. and Gemzell, C.A. (1963) Biochim. Biophys. Acta 74, 525). A first control of its purification and integrity was performed through molecular weight determination by gel filtration on Sephadex G-100 and on polyacrylamide gel electrophoresis (PAGE). Its biological activity was confirmed by the growth promoted in non-hypophysectomized rats at plateau. The main object, however, was the setting up of accurate, reproducible method tha could furnish the more absolute and comparable values of radioimmunoassayable HGH content in perfect agreement with the results obtained by other laboratories. This was accomplished through a radioimmunoassay system that uses HGH labelled with 125I, where separation of the bound from the free antigen is achieved on polyacrylamide gel electrophoresis, by a modification introduced in the original method of Davis. The resulting values, extremely close to that stated by the KABI-Laboratories (Stockolm), though obtained in quite different conditions of incubation, antibody concentration and with no use of second antibody, represent a confident approach to a comparable measure of this hormone in extracts, which can also be applied to plasma determinations.

Animals↗