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Biomedical subjects

M Hartmann

Publications and source records attributed to M Hartmann.

At least 343 records · Page 19Linked to original sources
PubMed1989

Intramucosal pH measurement with tonometers for detecting gastrointestinal ischemia in porcine hemorrhagic shock.

Intraluminal pCO/ was measured in the stomach, small intestine, and sigmoid colon of pigs using balloon catheters (Tonomitor). With the simultaneously determined arterial blood HCO3 concentration, the intramucosal pH (pHi) could be calculated using the Henderson-Hasselbalch equation. Cardiac output and portal venous flow were measured using Swan-Ganz catheters. A series of 35 normotensive pigs were studied to achieve normal values of cardiac output, gastrointestinal pHi, and blood flow in pigs. In another series of pigs (n = 12), hemorrhage was induced in two steps and followed by retransfusion. Five additional animals served as controls. Gastric, small intestinal, and colonic pHi decreased with increasing degree of hemorrhage but remained unchanged in the controls. Following severe hemorrhage, pHi fell below the normal range in all pigs but one. It recovered only partly following retransfusion. Histological examination of specimens obtained following retransfusion revealed normal mucosa in six of eight investigated animals and superficial mucosal injury in the remainder, indicating that abnormal pHi may be found for a period in the microscopically normal gastro-intestinal mucosa. Monitoring pHi in the stomach, small intestine, or colon using tonometers could be a useful technique to reveal insufficient mucosal blood flow in the alimentary canal.

Animals↗
PubMed1989

[Contrast sensitivity in dialyzed patients].

In a group of 57 patients with chronic terminal renal insufficiency, treated by haemodialyses a significantly reduced sensitivity to contrast was observed. Changes in the sensitivity to contrast do not correlate with the period of dialyzation treatment.

Adolescent↗
PubMed1989

[Detection of Mycoplasma hominis and Ureaplasma urealyticum in patients with leukospermia].

Cytological and microbiological tests were applied to urethral and prostate secretion, initial, midstream, and postmassage urine, and ejaculate of 61 patients with granulocyte counts of approximately 2 million/ml sperm, using the working principle of four-tube testing. Findings included 8 cases of chronic urethritis (caused by Chlamydia trachomatis in 5 instances, Ureaplasma (U.) urealyticum in 2, and Mycoplasma (M.) hominis in 1), 11 cases of chronic bacterial prostatitis, most of them in concomitance with urinary tract infections, and another 11 cases of "abacterial" prostatitis caused by mycoplasma (U. urealyticum in 10 cases, M. hominis in 1). No pathogens at all were recordable from 31 patients, among these 22 without leucocyte proliferation in urethral and prostate secretion nor in urine sediments. While no positive cytological findings were recordable from controls, significant germ counts of U. urealyticum were exhibited by 4 probands. The above findings are discussed together with their problematic interpretation.

Humans↗
PubMed1989

Computer-aided three-dimensional reconstructions of biological objects using simple facilities.

An analysis of serial sections is an important method applied in all fields of biology studying objects divided into sections, especially at light and electron microscopy levels. It affords a qualitative and quantitative information on spatial organization of tissues, cells and organelles. This study describes simple and cheap ways of obtaining computer-aided three-dimensional reconstructions of biological objects from serial sections.

Computer Graphics↗
PubMed1988

Expression of the human interferon-alpha 1 gene under transcriptional and translational control of the speA gene.

The human gene for mature interferon-alpha 1 (IFN-alpha 1) was inserted in a new transcription-translation fusion vector system based on the expression and secretion signals of the gene for type A streptococcal pyrogenic exotoxin, speA. As deduced from the known nucleotide sequences of the component elements, the encoded IFN-alpha 1 was a fusion protein carrying an N-terminal extension of 17 amino acids. When inserted in appropriate vectors capable of replication in Escherichia coli, Bacillus subtilis and Streptococcus sanguis, this expression configuration directed the synthesis of antiviral activity in all 3 organisms, as judged by the cythopathic effect inhibition assay of Vesicular Stomatitis Virus. In E. coli JM101, IFN activity was found mainly in the cytoplasmic protein fraction whereas in the gram-positive hosts, it was completely secreted into the culture medium.

Amino Acid Sequence↗
PubMed1988

Value of computed tomography in the staging of testicular tumors.

To analyze the value of computed tomography (CT) for the exact staging of testicular tumors, 2 groups of 28 patients each were examined. All patients underwent retroperitoneal lymph node dissection in the course of their treatment. Pretherapeutic stages as determined by CT were compared to the histologically verified definite tumor stages. In 68% of the patients, the stage found by CT was correct but 3 (5%) false-positive and 13 false-negative results were obtained. Thus, almost 40% (13/33) of the patients with clinical stage I disease presumably would have had a progression if managed by a surveillance strategy. It can be concluded that this strategy should be restricted to certain centers with guaranteed long-term standardized patient observation and extremely high patient compliance.

Dysgerminoma↗
PubMed1988

Benign testicular tumors: a case for testis preservation?

Between June 1980 and June 1986, 345 inguinal explorations for intrascrotal space-occupying lesions were performed. In 47 patients benign testicular tumors were diagnosed (13.5%). In 32 of the 47 tumors (68%), the testis could be preserved by excision or enucleation of the tumor. In the remaining 15 patients a high semicastration was carried out: in 12 cases macroscopic examination or frozen section revealed doubtful benignity (6 Leydig cells tumors, 5 dermoid cysts and 1 epidermoid cyst), in 3 patients because of extensive involvement of the testis. In a follow-up period of 1-7 years none of the patients has shown evidence of tumor recurrence or metastasis. Changing the concept of not incising the parietal tunica of the testis and regarding clear-cut macroscopic and histological criteria of benignity on frozen section will safely lower the testicular loss rate from up to 80% to about 30% when benign tumors are encountered.

Dermoid Cyst↗
PubMed1988

Early and long-term toxicity in the management of advanced germ cell testicular tumors.

47 patients with advanced germ cell testicular tumors were treated with combination chemotherapy, cis-platinum, vinblastine and bleomycin (PVB). All patients were reexamined on average 2.5 years after the end of treatment. Persistent mild long-term toxicity affecting the lungs, kidneys and peripheral nerve system was found in about one third of the patients. In addition, 32 patients who had received radiation therapy of seminoma were reexamined. Objective long-term toxicity was rare. However, possible damage to chromosomes and spermatogenesis has to be kept in mind.

Adult↗
PubMed1988

[Pathogen spectrum of non-gonorrhea urethritis].

By cultural investigations in 333 males with non-gonorrhoical urethritis (NGU) and 158 control probands it was demonstrated that Chlamydia trachomatis is the main germ of this disease also in the GDR with a frequency of 40% of the cases. A chlamydia-negative NGU was caused in 15% by Ureaplasma urealyticum in a number of greater than or equal to 10(4) germs/ml urine and in 5% by Trichomonas vaginalis, respectively. Candida albicans occurred significant more frequently in the patient group (21%) than in the control group (4%). Other optional pathogenic bacterias were the cause of NGU in single cases. The diagnosis and therapy of NGU should be considered this germ spectrum and the sexual partner also.

Bacteria↗
PubMed1988

[Changes in the EEG background rhythm and in the hyperventilation effect at different stages of HIV infection].

The visual evaluation of 370 clinical EEGs of 125 patients in different stages of the HIV-infection as well as 42 HIV-seronegative volunteers of the same high risk population (male homosexuals) proved the increasing appearance of CNS dysfunction with progression of the disease. An especially established hyperventilation-index for a semiquantitative evaluation of hyperventilation response showed an increase of slow-wave activity in the course of the infection. The appearance of slow-waves as well as a significant slowing of background activity in advanced stages of the HIV-infection can be regarded as unspecific signs of a beginning diffuse functional CNS disorder caused by a direct affection of the CNS through the Human Immunodeficiency Virus (HIV). The EEG changes in early stages are not specific as to their causative agent and do not allow the distinction between primary and secondary CNS involvement. The changes may precede clinical-neurological alterations.

AIDS-Related Complex↗
PubMed1988

[The effect of a reference electrode on the configuration of somatosensory evoked potentials].

Early somatosensory evoked potentials to median nerve stimulation were recorded in 6 normal adults from the scalp and the neck. Simultaneous derivations consisted of a recording with a cephalic reference, recordings of both electrodes with a noncephalic reference and an arithmetically subtraction of these potentials. The electrodes were placed over the scalp (P4'), the lower and the upper neck and the reference electrodes over the midfrontal region (Fz), both ears (M1/2) and the contralateral hand. P15/P16 in the P4'-Fz derivation had no identity to the far field potentials (FFP) P13/P14 recorded from the scalp with hand reference. FFP P9 and P11 from the ear lobes was abolished in the P4'-M1/2 derivation and the residual positive waves corresponded to P13 and P14. None of the electrodes picked up a wave equivalent to P15 regardless of the reference electrode. In the neck (CV 7) - scalp derivation NSEP9, 13 and 14 corresponded to the FFP P9, 13 and 14. NSEP11 differed in latency from P11 and N11. There was no latency shift from the lower (CV 7) to the upper (CV 2) neck. NSEP9 and 11 was enhanced in amplitude from CV 7, which resulted from different polarities (N11/P11) over CV 7 and CV 2. These results indicate the necessarity of potential analysis with respect to the activity of the recording electrodes.

Adult↗
PubMed1988

[Nongerminal, benign testicular tumors--report of experiences].

Between 1983 and 1986 179 inguinal testicular explorations were performed. Testicular palpation and sonograms were carried out. 163 patients (91%) had malignant testicular tumours. 16 patients (9%) were found to have benign, nongerminal testicular tumours. When intraoperative frozen section diagnosed epidermoid cysts, the majority of these were enucleated, while the dermoid cysts and Leydig cell tumours were removed together with the testicle. The postoperative follow-up on all patients showed no evidence of local recurrence or metastases.

Dermoid Cyst↗
PubMed1988

Structure-release relationships of physically based polymer-biocide combinations. Part 3: Effect of the environment on the release of 3(5)-methylpyrazole from monolithic matrix systems.

The release behaviour of the antimicrobially active 3(5)-methylpyrazole from matrix systems prepared from maleic anhydride copolymers as well as from copolymers of maleic esters and maleic amides was studied. Under alkaline conditions erosion is the predominant release mechanism compared to the release of the agent by diffusion into neutral or acid media. The presence of potassium and calcium salts influences the release rate under aquatic conditions in a different way. The diffusion rate of the active ingredient through membranes of maleic anhydride copolymers also depends on interactions with the surrounding media as well as on the hydrophilicity of the matrix.

Anti-Infective Agents↗
PubMed1987

Morphology of normal and malignant germ cells.

By means of semithin section histology and electron microscopy the following male germ cells are described: gonocytes and prospermatogonia in the embryonic and fetal testes; spermatogonia and primary spermatocytes in the testis of the adult; abnormal spermatogonia and spermatocytes, which are not tumour cells. In contrast to these cells, four main tumour cell types which on the basis of morphological criteria can be said to be derived from germ cells, are classified and designated as Tc 1 to Tc 4. The various tissues accompanying the tumour cells are briefly described.

Humans↗
PubMed1987

Past and recent attempts to model mortality at all ages.

"Most laws of mortality are partial in the sense that they apply only to a broad age group and not to all ages. This paper focuses on three laws of mortality that apply to all ages. Two of them were developed by the actuaries Thiele and Wittstein in the late 19th century. The third, developed by Heligman and Pollard, is of recent origin. The three laws are discussed with references to Scandinavian mortality data. The results suggest that the most recently proposed law can be used for generation of model life tables, for making population projections, simulations, and other statistical work where there is a need for a realistic model of human mortality."

Age Factors↗