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Biomedical subjects

C Hartmann

Publications and source records attributed to C Hartmann.

At least 217 records · Page 12Linked to original sources
PubMed1981

[Indirect contact specular microscopy. A new technique for the in vivo examination of the posterior corneal surface (author's transl)].

A new application of contact specular microscopy (CSM) is presented. This technique allows, in addition to conventional CSM and by augmentation of the applanation pressure of the CSM dipping cone, to observe changes on the posterior corneal surface in a three-dimensional mode. This technique gives valuable information in cases of preendothelial, endothelial, and retroendothelial modifications, leading to prominent changes of the posterior corneal surface. Thus, it is a very suitable method to interpret in vivo morphological findings. A hypothesis of the mechanisms leading to the three-dimensional image is presented. Based on these optical considerations the term 'indirect CSM' is proposed in contrast to the conventional direct CSM.

Animals↗
PubMed1979

Polyribosomes from Pear Fruit: Changes during Ripening and Senescence.

Polysome profiles were examined from lyophilized peel tissue of ripening pear (Pyrus communis, L. var. Passe-Crassane). Messenger RNA chains bearing up to eight ribosomes (octamers) were resolved and exhibited the highest absorption peak when ribonuclease activity was eliminated during extraction. Neither normal ripening nor the increase of large polyribosomes that normally accompanies ripening and senescence of the fruit occurred when pretreatment at 0 C was omitted. Normal ripening and increase of large polyribosomes would, however, be initiated by an ethylene treatment. The size distribution of the polyribosomes remained essentially constant throughout a 4-month cold storage; there was, however, a large increase in ribosomes by the 12th week of storage.

Journal Article↗
PubMed1976

The prognostic significance of first and second remission after first and second relapse radiotherapy in Hodgkin's disease.

New aspects concerning the prognostic importance of remission following first treatment and second relapse treatment have resulted from a retrospective study of 175 patients who received primary treatment for Hodgkin's disease between 1964 and 1971. By means of renewed radiotherapy 27 out of 66 (=41%) patients were again brought to full remission with 10 of the 66 (=15%) patients reaching partial remission. The prognosis of the second full remission is equal to that of the first full remission, the prospect of cure being retained. The prognosis of relapse patients following renewed radiotherapy is dependent on: 1. the type of the previous remission, whether full or partial, 2. the localization of the recidive, 3. the primary stage and the presence (or absence) of signs of activity B, 4. the histology, and 5. the age of the patient.

Adolescent↗
PubMed1975

[Treatment of bradycardia with an atropine ester].

In view of the unsatisfying drug treatment of bradycardias in most cases, clinical studies with new compounds seem to be urgent. A report is given on experiences with a derivative of atropine (gen. Ipratropiumpromid) in 34 cases suffering from various types of bradycardias. Comparing heart rate following intravenous injections of 0.5 to 1.0 mg, the new drug proved to be definitely more effective than atropine sulfate. Side effects were limited to diminution of salivary glands function.

Adolescent↗
PubMedDate not supplied

Characterization of two minicircular plasmid-like DNAs isolated from date-palm mitochondria.

We report here the identification and characterization of two minicircular plasmid-like DNAs isolated from mitochondria of a moroccan date-palm variety. Both molecules were cloned and used as probes in Southern analyses of mitochondrial and total-cellular DNA. Evidence was obtained that these plasmid-like DNAs cross-hybridized but did not show any homology to nuclear, chloroplastic, or main mitochondrial genomes. Sequence analysis revealed that both minicircles, 1,346- and 1,160-bp long, share several stretches of homology, the most important consisting of three identical clusters of lengths 42, 47 and 38 bp. In contrast, no major homology was observed with the other higher-plant plasmid-like DNAs reported so far. Sequence analysis also revealed the presence, in the same strand of one of the minicircles, of two open reading frames potentially encoding proteins 89 and 86 amino acids in length. Interestingly, Northern analyses, using single strands of each minicircle as probes, showed the presence of two transcripts hybridizing only with the strand bearing these two open reading frames. However, computer-assisted comparison of the predicted polypeptide sequences with a protein-sequence library failed to detect any significant homology to known sequences.

Base Sequence↗
PubMedDate not supplied

Pertussis complications in Germany--3 years of hospital-based surveillance during the introduction of acellular vaccines.

Between 1 November 1993 and 31 October 1996, admissions to paediatric departments for Bordetella pertussis complications were reported to a nationwide, hospital-based active surveillance system. The case definition included pertussis complicated by pneumonia, apnoea requiring assisted ventilation, seizures, encephalopathy or a combination of these. Two hundred sixteen cases of pertussis complications were registered. 57.4% of them were in infants, 50.9% of them less than 6 months old. There were five deaths, three previously healthy children died. At the time of hospital admission, 106 cases would have been eligible for at least three doses of pertussis vaccine, only four (3.8%) had received the recommended number of immunisations. From the second quarter of 1995, the reported number of cases declined. The decrease coincides with an improvement of pertussis vaccination coverage between 1992 and 1995 due to an increased use of acellular vaccines. The reduction of complicated pertussis was observed even in age-groups too young for the recommended vaccinations. The observed decrease could be due to the increase in vaccination coverage with interruption of the chain of transmission to the younger age-groups, to a cyclic decrease in pertussis cases, or to a combination of both. Continued surveillance will provide information on the epidemiological trend of hospitalisations for pertussis complications in the first European country to have introduced vaccination with acellular vaccines on a large scale.

Child↗
PubMedDate not supplied

Determination of the mineral content and the transparency of the root dentine of human teeth.

One hundred and fifty-six teeth were extracted from corpses aged between 15 and 79 years. Of these, 101 teeth were selected for measurement of the mineral content of the root by photon beam absorption. Six or seven cross-sections were measured in each root, and the mean values calculated for the apical, medial, and coronal part within each decade. Further, 20 selected teeth were embedded in methacrylate and the length of the zone of transparency determined in longitudinal sections. There was no significant age dependency of the root's mineral content. There was no correlation between the extent of transparency and the mineral content.

Adolescent↗
PubMedDate not supplied

No effect of prophylactic treatment with metoprolol on cerebrovascular CO2 reactivity in migraineurs.

The prophylactic effect of metoprolol in the treatment of migraine is well known, but its mode of action is still unclear. In the past, increased CO2 reactivity has been reported as one pathognomic finding in interictal migraineurs. Using transcranial Doppler we assessed CO2 reactivity in 20 migraineurs before and 3 h after the first intake of 50 mg metoprolol, and subsequently twice after 1 and 8 weeks of continuous therapy with 150 mg metoprolol/d. Before initiation of therapy, migraineurs as a group had increased CO2 reactivity (p=0.07) compared to 20 age- and sex-matched volunteers. While treatment with metoprolol has been reported to affect amplitudes of increased contingent negative variation or visual evoked potentials in interictal migraineurs, it had no influence on enhanced CO2 reactivity in the present study. Moreover, the pretreatment value of CO2 reactivity did not correlate with the clinical efficacy of metoprolol after a 2-month treatment period.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Treatment of rubeosis iridis with photodynamic therapy with verteporfin--A new therapeutic and prophylactic option for patients with the risk of neovascular glaucoma?

Patients with ischaemic retinopathy who show iris neovascularization despite panretinal laser photocoagulation (PRP) very often develop a neovascular glaucoma. Photodynamic therapy (PDT) has been shown to occlude neovascularization without damage to physiologic vessels or adjacent tissue in the treatment of choroidal neovascularization (CNV) and might also be of value for patients with neovascular glaucoma who did not benefit from the PRP. First results of a monocentre, open label, intra-individual controlled, pilot phase I/II, dose-finding study demonstrate that PDT with verteporfin is capable of occluding neovascular vessels for a defined period of time without damaging adjacent tissue or physiologic iris vessels. Whether this vessel occlusion will have an impact on the progression of rubeosis or neovascular glaucoma will be the subject of further investigation.

Glaucoma, Neovascular↗
PubMedDate not supplied

Correlation study of two methods for evaluating corneal endothelial damage in vitro: the Janus green photometry technique versus cell counting.

Counting of endothelial cells after vital staining is a time-consuming method which, in addition, requires considerable experience and does not normally allow for the study of the entire endothelial cell surface. However, the Janus green photometry technique (JGPT) is an objective, time- and personnel-saving procedure which also has the advantage of allowing for the evaluation of the whole endothelial cell surface. A comparative simultaneous experimental study of the two methods had not been reported. Freshly excised pig corneas (n = 58) were preserved in MK storage medium for 4, 7, 14 and 20 days at 4 degrees C. All corneas were stained with Janus green and alizarin red. A 7-mm corneal button corresponding to an endothelial surface of 38.46 mm2 was punched out. The percentage of damaged cells was determined with cell counting (CC) and with JGPT, and the results were statistically compared. Two methods for CC were used. Cells were counted either directly under the microscope or in photomicrographs. The overall correlation between the results of CC and JGPT was R = 0.98. However, when endothelial cell damage was higher than 30%, CC became an estimation by approximation, since necrotic areas were confluent, whereas with JGPT the results were usable even when the damage was 100%. Thus it appears that although the two methods can be used interchangeably, JGPT may in some instances be the method of choice.

Animals↗
PubMedDate not supplied

[Prevention of secondary cataract by intracapsular administration of the antimitotic daunomycin].

Pharmacological inhibition of capsule opacification e.g. using antimitotics such as daunomycin is a promising concept. Our own in vitro studies on cultured porcine lens epithelial cells have shown, that daunomycin penetrates the cells within at least 5 minutes. It possesses a low acute cytotoxicity and significantly inhibits epithelial cell proliferation at dose dependent concentrations ranging from 2.5 to 7.5 mg/l. In addition, in vitro studies on isolated pig corneas showed almost no corneal endothelial toxicity. After 10 resp. 30 min. exposure to 7.5 mg/l daunomycin, there was only 4.8 +/- 1.6 resp. 6.1 +/- 1.5% endothelial damage that dit not significantly differ from BSS serving as control. Encouraged by our clinical experience of good anterior segment tolerance of 7.5 mg/l daunomycin when used during vitrectomy in PVR, we started a prospective clinical trial to assess the effect to daunomycin on capsular opacification after ECCE with endo-capsular IOL implantation using the envelope technique. After agreement of the medical ethic commission we chose 6 patients with a mean age of 78 (72-83), no other ocular or general diseases and bilateral cataract of identical morphology and density. After written consent of the patients their first eye was operated using BSS as control. At least 4 weeks later the second eye was operated and received 0.5 ml of daunomycin (7.5 mg/l) applied during 5 minutes into the cleaned capsular bag, leaving the anterior capsular flap and a Healon filled anterior chamber to protect the surrounding intraocular structures. Mean postoperative control time actually is 12 (6-17) months for the controls and 10 (5-14) months for the eyes treated with daunomycin.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗