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Biomedical subjects

C Hentschel

Publications and source records attributed to C Hentschel.

At least 19 recordsLinked to original sources
PubMed2003

Refilling of cortical calcium stores in Paramecium cells: in situ analysis in correlation with store-operated calcium influx.

This is the first thorough study of refilling of a cortical calcium store in a secretory cell after stimulation in which we combined widely different methodologies. Stimulation of dense-core vesicle ("trichocysts") exocytosis in Paramecium involves a Ca(2+) -influx" superimposed to Ca(2+) -release from cortical stores ("alveolar sacs" (ASs)). In quenched-flow experiments, membrane fusion frequency rose with increasing [Ca(2+)](o) in the medium, from approximately 20-25% at [Ca(2+)](o) < or = 0.25 microM to 100% at [Ca(2+)](o) between 2 and 10 microM, i.e. close to the range of estimated local intracellular [Ca(2+)] during membrane fusion. Next, we analyzed Ca(2+)-specific fluorochrome signals during stimulation under different conditions. Treatment with actin-reactive drugs had no effect on Ca(2+) -signaling. In double trigger experiments, with BAPTA in the second secretagogue application (BAPTA only for stimulation and analysis), the cortical Ca(2+) -signal (due solely to Ca(2+) released from cortical stores) recovered with t(1/2) approximately 65 min. When ASs were analyzed in situ by X-ray microanalysis after different trigger times (+Ca(2+)(o)), t(1/2) for store refilling was similar, approximately 60 min. These values are similar to previously measured 45Ca(2+) -uptake by isolated ASs. In sum we find, (i) exogenous Ca(2+) increases exocytosis/membrane fusion performance with EC(50)=0.7 microM, (ii) Ca(2+) -signaling in this system is not sensitive to actin-reactive drugs, and (iii) refilling of these cortical calcium stores goes on over hours and thus is much slower than expected.

Actins↗
PubMed2002

Profiling 'centres of excellence' in CAM research.

Several 'centres of excellence' of research in complementary/alternative medicine (CAM) have emerged in recent years. This study represents an attempt to profile the most productive of these centres. Medline searches (1995-2001) were performed with a long list of individuals directing CAM research groups as key words. Eight of them (all male) had published in excess of 20 Medline-listed articles between 1995-2001, and this group was evaluated in further detail. Three originated from the US and two from the UK. Collectively this group had published 32 clinical trials, an equal number of surveys and 95 systematic reviews. The range of research subjects for most centres was narrow. It is concluded that several active CAM research centres are well established. Their output is variable and, in most cases, leave room for improvement. Probably because of funding difficulties, clinical trials remain rare.

Clinical Trials as Topic↗
PubMed2000

Development of a creatinine ELISA and an amperometric antibody-based creatine sensor with a detection limit in the nanomolar range.

Creatinine-specific antibodies have been generated and used for highly sensitive and specific immunochemical creatinine determinations. Creatinine was derivatized at N3 and coupled to KLH carrier protein. On the basis of this immunogen, monoclonal antibodies were developed by hybridoma technology. Antibodies from various clones have been characterized with BIAcore 2000 with respect to the dissociation constant and specificity. Antibodies of clone B90-AH5 exhibited the lowest dissociation constant (0.74 microM) and the highest specificity for creatinine and were chosen for the development of a competitive ELISA and an amperometric creatinine sensor. The creatinine sensor was constructed by fixing a creatinine-modified membrane on the top of a platinum working electrode which was then incorporated into a stirred electrochemical measuring cell. For creatinine determination the creatinine-containing sample was incubated with B90-AH5 and anti-IgG(mouse)-glucose oxidase conjugate and applied to the measuring cell. After a washing step glucose was added and the produced hydrogen peroxide was registered at Eappl = +600 mV vs Ag/AgCl. The measuring range was 0.01-10 microg/mL. The highest sensitivity for creatinine was achieved at 330 ng/mL (3 microM) and the lower detection limit at 4.5 ng/mL (40 nM). This is far below the relevant clinical range, which is 5-17 microg/mL (44-150 microM) and allows a reliable determination of very low creatinine concentrations in serum, where standard methods cannot be applied. After each measurement the sensor was regenerated with 10 mM HCl without any loss in binding activity.

Antibodies, Monoclonal↗
PubMed1999

Efficacy and safety of a fixed combination phytomedicine in the treatment of the common cold (acute viral respiratory tract infection): results of a randomised, double blind, placebo controlled, multicentre study.

OBJECTIVE: The common cold (acute viral respiratory tract infection) is one of the most frequent diseases in man, world-wide. Clinically relevant efficacy should include early improvement of all symptoms. Results of a clinical trial of a commercially available fixed combination herbal remedy (Radix echinaceae, Radix baptisiae, Herba thujae) are reported here. The aim of this study was to verify clinical efficacy shown in recent studies under (i) good clinical practice (GCP) quality assurance and (ii) common situations at family doctors. METHODS: Patients attending one of 15 study centres (practitioners) as a result of an acute common cold were randomised to the double-blind placebo-controlled study. Three tablets of study medication were applied t.i.d. for 7 to 9 days. Patients daily documented the intensity of 18 cold symptoms, as well as the cold overall, using a 10-point scale and estimated their general well-being using the Welzel-Kohnen colour scales. Additionally, the severity of illness was assessed by the physician on days 4 and 8 (CGI-1). The main and confirmatory outcome measure was expressed as a total efficacy value. This was gauged from the z-standardised AUC values of the primary endpoints (rhinitis score, bronchitis score, CGI-1 and general well-being). Adverse events, overall tolerability, vital signs and laboratory parameters were documented. RESULTS: 263 patients were included. For safety analysis, all patients were used. 259 patients were evaluable for primary efficacy analysis (ITT). Results were confirmed analysing only the 238 valid cases (VCs). The primary efficacy parameters showed the superiority of the herbal remedy over placebo (p < 0.05). Effect size was 20.6% of the standard deviation (90% CI: 0.04-41.1%; ITT) and 23.1% (1.7-44.5%; VC). In relation to the general well-being, the effect size was 33.9% of the standard deviation (12.5-55.3%; VC). Patients who suffered from at least moderate symptom intensity at baseline showed response rates (at least 50% improvement of the global score, day 5) of 55.3% in the herbal remedy group and 27.3% in the placebo group (p = 0.017; NNT = 3.5). In the subgroup of patients who started therapy at an early phase of their cold, the efficacy of the herbal remedy was most prominent (p = 0.014 for the primary efficacy parameter). The therapeutic benefit of the herbal remedy had already occurred on day 2 and reached significance (p < 0.05) on day 4, and continued until the end of the treatment in the totdl score of symptoms, bronchitis score and rhinitis score, as well as in the patients' overall rating of the cold intensity. At that time, equal levels of improvement were reached three days earlier in the verum group than in the placebo group. In 26 patients receiving the herbal remedy and 23 patients receiving placebo, adverse events were reported. Adverse drug reactions were suspected in two patients in the verum group and in four patients in the placebo group. Serious adverse events did not occur. CONCLUSIONS: This study shows that the herbal remedy is effective and safe. The therapeutic benefit consists of a rapid onset of improvement of cold symptoms. If patients with colds are able to start the application of the herbal remedy as soon as practical after the occurrence of the initial symptoms, the benefit would be expected to increase (e.g. self-medication).

Adult↗
PubMed1996

[Decision to use complementary medicine: fact oriented or irrational?].

PROBLEM AND OBJECTIVE: Complementary medicine is being used to varying extent in all industrial countries. There are incomplete data concerning efficacy, safety and costs of such treatment, while little is known about special features and motivation of those persons who choose complementary medicine. The aim of the study was to ascertain, among patients who use complementary medicine and those who prefer traditional medicine, any differences with regard to sociodemographic, disease-related and psychological characteristics and their life-style. PATIENTS AND METHODS: A total of 419 patients were studied by a standardised interview and questionnaire (168 items) and divided into two groups (group 1: those using conventional treatment [n - 197; 91 women, 106 men; average age 43.2 +/- 16.9 years]; group 2: those preferring complementary medicine [n = 222; 159 women, 63 men; average age 43.2 +/- 15.0 years]). They were recruited from specialist internal medical or generalist medical practice with or without offer of complementary medicine (additional term: natural healing methods). Statistical analysis was with Student's-t-test and the chi(2)-test [correction of gamma-test]. RESULTS: Those patients who chose to be treated by complementary medicine clearly differed from the others with respect to sociodemographic, disease-related and psychological characteristics, as well as life-style. The patient-doctor relationship also differed between the two groups. On average those of group 2 had a higher educational level (higher education: 10.3% in group 1; 15.9 in group 2) and lower risk factors (68.9% nonsmokers in group 1, 77.8% in group 2; alcohol abstinence: 33.2 vs 46.4%). Patients in both groups preferred conventional medicine for serious diseases (cardiac infarct; tumour; AIDS). CONCLUSIONS: In general, those patients who choose complementary medicine have a healthier life-style. As the number of these patients is on the increase. Since as yet the efficacy, risks and costs of complementary medicine have been inadequately investigated, research in this area should be intensified.

Adult↗
PubMed1996

[Curcuma xanthorrhiza (Java tumeric) in clinical use].

The rhizome of Curcuma xanthorrhiza has been used for medical purposes for hundreds of years. A related plant, but which contains other constituents, is C. domestica, which is used in the manufacture of curry powder. Both experimental and clinical studies have revealed, in particular, a choleretic effect. In addition, in part in animal experimental studies, antilipidemic, analgesic-antiphlogistic and antimicrobial effects have also been found.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1996

[ICD diagnoses in university polyclinic naturopathy consultation].

In a special consulting office for complementary medicine, ambulatory patients interested in receiving adjuvant treatment with complementary medicine can obtain a relevant advice and critical information regarding non-evaluated therapies. Within the framework of a retrospective statistical analysis, the diagnosis documented over a period of 24 months in accordance with the 4-digit ICD code were evaluated. In particular patients with chronic and/or functional illnesses had additional treatment needs. The exponential growth in the numbers of patients during the course of the observation period illustrates the increasing importance of complementary medical measures. However, in view of the considerable political significance of the cost factor and the possible risks of the treatment, only properly evaluated complementary medical therapies should be employed.

Adolescent↗
PubMed1995

[Fumaria officinalis (fumitory)--clinical applications].

Fumaria officinalis-fumitory or earth smoke-is a medicinal plant which has long had a role to play in empirical medicine in numerous countries. A review of the literature, however, reveals very few studies that support its use for dermatological indications (milk crust, eczema, scabies, etc.) or as a diuretic or laxative. This contrasts with its use to treat functional diseases of the biliary system. Although no placebo-controlled studies have been done, a number of empirical reports, clinical case reports and animal experimental studies have been published. Accordingly, in Germany, Fumaria officinalis is approved for the indication "colicky pain affecting the gallbladder and biliary system, together with the gastrointestinal tract".

Animals↗
PubMed1994

[Contact regulation thermography: a useful diagnostic procedure?].

Contact regulation thermography is one of the unconventional medical diagnostic procedures, and is based on the individual adaptive behavior of the subject with respect to temperature. Its proponents believe that a specific medical diagnosis can be established on the basis of varying temperature differences. Studies carried out to date have produced mixed results. The increasing use of this procedure, not only in complementary medicine, makes it necessary to undertake a critical examination of the method. Care-providing physicians should question their patients about other unconventional medical diagnostic procedures to which they have been submitted, and inform them about the dubious nature of non-evaluated methods.

Body Temperature Regulation↗
PubMed1991

A solid-phase enzyme immunoassay for the detection of tetanus toxin using human and murine monoclonal antibodies.

Three human and three murine monoclonal antibodies were tested for their reactivity to tetanus toxin and toxoid and used to establish an enzyme immunoassay specific for tetanus toxin. The dissociation constants of the monoclonal antibodies were between 3.91 x 10(-9) and 8.48 x 10(-12). Two human monoclonal antibodies recognized conformation determinants on the toxin, whereas the others reacted to the heavy chain. Only a combination of antibodies of the two species allowed the development of an enzyme immunoassay for the detection of tetanus toxin with a lower detection limit of 1.2 micrograms/l.

Animals↗
PubMed1990

[Use of fermenter-dialysis culture for the cultivation of medically relevant microbes. III. Candida albicans].

For mass cultivation of Candida albicans (serotype A), a fermenter dialysis culture technique is described and compared with shaking culture and fermenter batch culture techniques. Important growth parameters such as yeast dry weight and viable cell counts demonstrate the advantage of the fermenter dialysis culture. Mannan, the major antigen from Candida albicans prepared by phenol-water extraction followed by gel chromatography was tested with the monoclonal IgM antibody H5.

Candida albicans↗
PubMed1990

Development of an immunoenzymometric assay for alpha 1-microglobulin and measurement of its serum concentration in normal and HIV-infected persons.

alpha 1-Microglobulin was purified from urine to a purity of 97.7% in a yield of 25.8%, and was used to produce antibodies in sheep. These antibodies, purified by affinity chromatography, were used to develop a rapid one-step and a two-step immunoenzymometric assay (IEMA). The equilibrium in the reaction between solid phase-adsorbed antibodies and antigen and between the antigen and enzyme-labelled antibodies was attained within 30 and 100 min, respectively. The one-step IEMA permits a good differentiation of low alpha 1-microglobulin concentrations after 30 min reaction time. Its detection limit is 0.35 micrograms/l, and its measurement range is between 0.5 and 100 micrograms/l. The IEMA correlates well with radial immunodiffusion (r = 0.973). The mean alpha 1-microglobulin serum concentration in women is insignificantly lower (33.2 mg/l) than in men (36.1 mg/l). In both sexes the alpha 1-microglobulin concentration increases with age. HIV-infected symptomless men have a significantly lower (15.9 mg/l) alpha 1-microglobulin concentration in serum than normal persons, whereas in AIDS patients it is significantly higher (45.5 mg/l).

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Glucose elevates the permeability of microcirculation vessels].

The measurements were accomplished by using an experimental setup in which an intestinal loop with adjacent mesentery of an anaesthetized rat was immersed in a buffer-containing cuvette. After i.v. injection of Evans' Blue (EB) the extravasation of the dye, which is bound to plasma albumin, was measured colorimetrically. From the curves recorded it could be derived that after i.v. injection of 2 or 4 g or infusion of 6 g/h glucose (Gk) per kg body weight the permeation of albumin-bound EB was increased by a factor of about 1.9, 3.1 and 2.0 respectively. As mechanism of these effects it is assumed that Gk (but also galactose and saccharose in control experiments) act by osmotically shrinking the endothelial cells and opening their junctions.

Animals↗