Search PubMed⌕ Search

Biomedical subjects

M Kraemer

Publications and source records attributed to M Kraemer.

At least 55 records · Page 3Linked to original sources
PubMed1998

Factors influencing human sperm kinematic measurements by the Celltrak computer-assisted sperm analysis system.

This study examines the effect of varying several factors, both extrinsic and technology-dependent, on the reconstruction of human sperm trajectories and the derived kinematic measurements using videotapes and the Motion Analysis Celltrak/S instrument. In semen samples from normal healthy men, curvilinear (VCL) and straight line velocities (VSL) were found to increase 1.5-fold, and linearity (LIN) of trajectories and amplitude of lateral head displacement (ALH) increased 1.25-fold when the temperature of analysis was raised from 24 to 37 degrees C. Only VCL and VSL were found to increase significantly between 24 and 37 degrees C for sperm samples selected by Percoll gradient and incubated in a capacitating medium. An analysis chamber of 20 microm depth was found to be adequate for seminal sperm samples while for Percoll-selected sperm samples the analysis in a 50 microm depth provided the highest proportions of spermatozoa with the highest VCL and the largest ALH. The grey level detection threshold required careful adjustment: using a threshold lower than the optimal threshold produced spurious sperm trajectories for seminal sperm samples and rejected some trajectories for Percoll-selected sperm samples. Definition of the appropriate frame rate and maximum burst speed was critical for valid trajectory reconstruction and therefore adequate derived kinematic measurements. Optimal values of these parameters were found to be 30 Hz and 400 microm/s for seminal spermatozoa and 60 Hz and 700 microm/s for selected spermatozoa. The optimal values of 'ALH path-smoothing factor' used to calculate average path and ALH were 5-10 points for seminal spermatozoa analysed at 30 Hz and 15-20 points for selected spermatozoa analysed at 60 Hz. We propose a set of standard conditions for reliable kinematic analysis of human spermatozoa using the Celltrak/S system.

Centrifugation, Density Gradient↗
PubMed1998

[Stepwise concept for treatment of complex anal fistulas].

Most anal fistulas can be easily dealt with by simple fistulotomy. So called complex fistulas-in-ano need a differentiated, individually tailored surgical approach in order to avoid recurrence and sphincter incompetence. Complex fistulas comprise either tracks with high trans-, supra-, or extrasphincteric extension or fistulas that are complicated by multiple side branches, chronic inflammatory disease, previous operations etc. Prior to treatment a thorough preoperative diagnostic work-up is warranted. A precise intraoperative evaluation is paramount to allow radical excision of all inflamed tissue, often necessitating anal sphincter division with subsequent reconstruction. The treatment plan involves staged operations over a period of many months, usually with the (laparoscopic) fashioning of a protective stoma at the primary operation. Analysing our patients in the study period from 1/95 to 12/96 our different surgical approaches and their results are presented and discussed. During this period 96 patients with a fistula-in-ano were operated upon in the Department of Surgery at Würzburg University Hospital, of which 11 (11.5%) had complex disease. We encountered one early and one late recurrence as well as a parastomal hernia and a stoma prolapse. Anal continence was re-assessed three months following reversal of colostomy. All patients (n = 7) who had perfect continence preoperatively remained unchanged. Preoperatively, four patients were incontinent for gas and liquid stool. Two of these were fully continent, one remained unchanged at re-assessment. The fourth patient did not undergo stoma reversal as yet, because all examinations revealed an incompetent sphincter. This patient is therefore fully incontinent. Successful treatment of complex anal fistulas needs an individual approach and planning over a lengthy period of time, requiring a high level of motivation on the part of both patient and surgeon.

Adult↗
PubMed1998

[The diagnostic value of rectal examination of patients with acute appendicitis].

The results of rectal digital examinations performed on 477 patients upon admission with histopathologically proven acute appendicitis from a total of 2280 patients with acute abdominal pain were analyzed. Although 13.7% of the patients experienced pain on the right side and 7.4% pain in the pouch of Douglas during rectal examination, none of the rectal examination parameters was statistically significant for the diagnosis of acute appendicitis. There are well established and statistically significant clinical indications, such as guarding, rigidity, rebound tenderness or abdominal distention that actually make the unpleasant rectal-digital examination superfluous for patients with suspected appendicitis.

Abdomen, Acute↗
PubMed1997

[A pilot investigation into the effects of extracorporeal shock waves on muscular dysfunction in children with spastic movement disorders].

INTRODUCTION: Extracorporeal shock waves (ESW) are being used increasingly frequently for the treatment of narrowly localized pain in the musculoskeletal system. Pain is normally associated with muscular dysfunction. Beginning with the observation that not only is the pain soothed by treatment with ESW, but that the muscular dysfunction itself is relieved, an attempt has been made to treat the impaired function in cases of infantile cerebral palsy with ESW. METHOD: In 35 children and young people with mainly spastic disturbances of movement, the bellies of those muscles producing the flexion contracture of the lower limb were each treated with 500 non-focused pulses of low-energy ESW. The focus (focal pressure 10 MPA=0.06 mJ/mm) of the shock waves itself was placed either within the coupling cushion of the therapy source (Minilith, Storz Medical, CH-Kreuzlingen) or obliquely outside the patient's body. In this way ESW could be dispersed throughout the muscles and the risk of undesirable effects was minimized. The energy used amounted to about 30% of the threshold value at which cellular damage from focused treatment with ESW had been observed in the endothelium of the human umbilical cord. RESULTS: The degree of movement at the hip joint increased after one treatment by an average of 17 degrees, at the knee joint by 12.3 degrees and at the ankle joint by 7.1 degrees, each increase being statistically significant. Muscular stiffness, spastic co-contractions, and myofascial viscoelasticity, as well as dyskinetic and ataxic symptoms, decreased. It appeared as if a systemic action had entered into the motor control. Together with an increase in general proprioception, there was an improvement in body image, in economy of movement and also in the limbs that had not been treated. A few patients showed euphoric reactions for about 2 days after treatment. No undesirable effects were observed during a follow-up of 12 months. The treatment was painless and is therefore suitable for children. The biomechanical improvement remained for several weeks and this time could be used for initiating an improved pattern of movement. CONCLUSION: ESW is suitable for use as an additional instrument for physiotherapeutic treatment of infantile cerebral palsy. The effective action of ESW on disturbed peripheral muscles has been discussed in terms of positive pressure and tensile wave forces and/or forces acting by cavitation. The results obtained in this pilot investigation showed particular a decrease in muscle stiffness. A controlled investigation with gait analysis and psychological control is to be undertaken.

English Abstract↗
PubMed1997

The value of endorectal ultrasound in the assessment of adenomas, T1- and T2-carcinomas.

In a prospective study we examined the value of endorectal ultrasound (ERUS) in the preoperative staging of potentially locally excisable tumours. During the study period from 1.1.1991 to 1.3.1996 a total of 160 rectal tumours in 152 patients were staged endosonographically (uT/uN) and compared postoperatively with the histologic result (pT/pN) at the University Hospital of Würzburg. Thirty-eight (24%) patients had an adenoma and 15 (9%) a T1-carcinoma. In 29 (18%) cases a T2-cancer was diagnosed, further 67 (42%) and 11 (7%) patients presented with a T3 and T4 tumour, respectively. The sensitivity for adenomas and T1-Ca (uT0/1) was 81%, the specificity 98%. For T2 tumours, the sensitivity was only 41% and the specificity 92% as the majority (17 of 29) of pT2 neoplasias were overstaged (uT3). The overall staging accuracy (T1-4) was 77.5%. Two patients with a pT1-Ca and seven with a pT2-Ca had lymph node metastases which were detected preoperatively in five. The accuracy for lymph node staging was 83%. We conclude that adenomas and T1 tumours can be assessed with a high grade of accuracy using ERUS. In these tumours ERUS can be used to assist clinical decision-making (transanal vs. abdominal operation). Owing to the lack of sensitivity ERUS is of no help in the assessment of T2 carcinomas.

Adenoma↗
PubMed1997

Expression of the Na+-D-glucose cotransporter SGLT1 in neurons.

In brains of the rabbit, pig, and human, expression of the high-affinity Na+-D-glucose cotransporter SGLT1 and of the protein RS1, which alters the activity of SGLT1, was demonstrated. In situ hybridization showed that SGLT1 and RS1 are transcribed in pyramidal cells of brain cortex and hippocampus and in Purkinje cells of cerebellum. In neurons of pig brain SGLT1 protein was demonstrated by western blotting with synaptosomal membranes and by immunohistochemistry, which showed SGLT1 in pyramidal and Purkinje cells. To test whether SGLT1 in neurons may be activated during increased D-glucose consumption, an epileptic seizure was induced in rat brain, and the uptake of specific nonmetabolized substrates of SGLT1 [[14C]methyl-alpha-D-glucopyranoside ([14C]AMG)] and of Na+-independent transporters [2-deoxy-D-[14C] glucose ([14C]2-DG)] was analyzed by autoradiography. During the seizure the uptake of AMG and 2-DG was increased in the focus. Within two hours after the seizure 2-DG uptake in the focus returned to normal. In contrast, the AMG uptake in the focus area was still increased 1 day later. The data show that the high-affinity Na+-D-glucose cotransporter SGLT1 is expressed in neurons and can be up-regulated.

Animals↗
PubMed1997

[Open surgical therapy of functional disorders of the rectum and pelvic floor].

An overview is given of common transabdominal procedures for functional disorders of the rectum and pelvic floor which are caused by degenerative morphological changes, and termed pelvic floor insufficiency. Only the transabdominal approach permits a comprehensive and pathophysiological repair of changes associated with the disorder. Own results and a review of the literature confirm a superior functional outcome and low recurrence rates with a combined procedure consisting of rectopexy, colonic resection and pelvic floor repair.

Colectomy↗
PubMed1997

[Is perforating appendicitis a separate disease picture?].

Large epidemiological studies recently published suggest that perforating appendicitis may represent a separate disease entity. To find out whether perforating and nonperforating appendicitis may be distinguished by clinical features (history and examination, lab tests) data from 519 cases of acute appendicitis (17.7% perforations) were analysed, and significant differences were recorded in various aspects of history and clinical examination. It was concluded that perforating and nonperforating appendicitis may clinically be distinguished reliably in the majority of cases.

Adult↗
PubMed1996

Low plasma thyroid indices of depressed patients are attenuated by antidepressant drugs and influence treatment outcome.

Decreased turnover of thyroid indices and blunting of TSH release after TRH administration has been associated with depressive disorder. A further decrease in plasma thyroid hormone; during antidepressant treatment has been reported. However, the putative association between the plasma thyroid indices' concentration and response has not been addressed. In the present study 21 depressed inpatients underwent a four-week double blind antidepressant with amitriptyline and mianserin; their plasma thyroid hormone indices (total thyroxine [TT4], free thyroxine [FT4], total triiodothyronine [TT3], free triiodothyronine [FT3], thyrotropin [TSH], and thyroglobulin [TBG]) were quantified to elucidate their involvement in depression and during antidepressant drug treatment. Depressed patients' plasma TSH, when corrected for age, was significantly lower than that of healthy subjects. During antidepressant treatment the entire patient cohort showed a significant decrease in plasma TT4 and FT4 concentrations. Responders showed a significant drop in TT4 FT4, FT3, and T4/TBG, but nonresponders only a decrease in FT4. During mianserin treatment, a decrease was observed in TT4, FT4, FT3, and T4/TBG. FT4 and FT3 baseline levels correlated positively with the improvement in the Hamilton Depression Rating Score (HDRS). These findings show that depressed inpatients' serum TSH levels are within the reference range, but significantly lower than those of healthy subjects, and those patients who turn out to be nonresponders have potentially lower availability of thyroid hormones than responders. Therefore, we hypothesize that in order to assure clinical improvement in depression, an adequate capacity of the thyroid hormone pool is necessary to compensate for the additional antidepressant-provoked decrease in serum thyroid hormone availability.

Adult↗
PubMed1996

Neuronal hyperexcitability and reduction of GABAA-receptor expression in the surround of cerebral photothrombosis.

Changes of neuronal excitability and gamma-aminobutyric acid (GABAA)-receptor expression were studied in the surround of photothrombotic infarcts, which were produced in the sensorimotor cortex of the rat by using the rose bengal technique. In a first series of experiments, multiunit recordings were performed on anesthetized animals 2-3 mm lateral from the lesion. Mean discharge frequency was considerably higher in recordings from lesioned animals (> 100 Hz in the first postlesional week) compared with control animals (mean, 15 Hz). These alterations were already present after 1 day but were most pronounced 3 to 7 days after lesion induction. Thereafter the hyperexcitability declined again, although it remained visible up to 4 months. In a second series of experiments, the GABAA-receptor expression was studied autoradiographically. This revealed a reduction of GABAA receptors in widespread brain areas ipsilateral to the lesion. The reduction was most pronounced in the first days after lesion induction and declined with longer intervals. It is concluded that cortical infarction due to photothrombosis leads to a long-lasting and widespread reduction of GABAA-receptor expression in the surround of the lesion, which is associated with an increased neuronal excitability. Such alterations may be responsible for epileptic seizures that can be observed in some patients after stroke and may contribute to neurologic deficits after stroke.

Animals↗
PubMed1996

[Etiology and epidemiology of anal incontinence].

Current epidemiological data about fecal incontinence are reviewed. Anatomy and physiology of the anal sphincter are described, and it is shown that continence relies on several interdependent anatomical and functional factors. Etiology of fecal incontinence is discussed and illustrated by clinical examples.

Diagnosis, Differential↗
PubMed1996

[Surgical therapy of rectal prolapse].

A review of literature and own clinical studies confirm that best postoperative functional results in complete rectal prolapse may be reached with rectopexy in combination with partial resection of the colon. Incontinence may be improved in 38% to 93%, depending on the author. Constipation may be reduced in 41% to 83% of the cases. In comparison, rectopexy without resection resulted in a reduction of constipation of only 11% to 28%, with even a change to the worse in 60% of the patients. Improved operative and anesthesiological conditions cause an acceptable perioperative morbidity (7-13%) and mortality (0-2%) after rectopexy with partial resection of the colon.

Colon↗
PubMed1996

[Anorectal endosonography in tumor after-care].

Due to its high resolution and the possibility to compare the images with previous examinations the transrectal ultrasound (TRUS) can lead to an earlier diagnosis of locally recurrent rectal cancers. Using TRUS we were able to correctly identify ten of 12 local recurrences. In four cases TRUS was the only diagnostic tool as neither the alternative imaging technique nor endoscopy were able to show the recurrence.

Endosonography↗
PubMed1995

Quantitative receptor autoradiography of eight different transmitter-binding sites in the hippocampus of the common marmoset, Callithrix jacchus.

The regional and laminar distributions of eight different transmitter-binding sites were measured in the marmoset hippocampus by means of quantitative in vitro receptor autoradiography. Receptors for 5-HT1, L-glutamate, N-methyl-D-aspartate (NMDA) and GABAA were similarly distributed. The highest concentrations of these receptors were found in the pyramidal layer of CA1 and the molecular layer of the dentate gyrus. The 5-HT2 receptors showed the highest concentrations in the oriens layer of CA2. The highest concentrations of muscarinic M1 receptors were seen in the pyramidal layer of CA1. Muscarinic M2 receptors were most densely concentrated in the pyramidal layers of CA1, CA2 and CA3. The noradrenergic alpha 1 receptors were most densely packed in the radiatum-lacunosum-molecular layer of CA2 and the molecular layer of the dentate gyrus. Statistically significant co-distributions of serotoninergic, glutamatergic and GABAergic receptors point to possible interactions between these receptor systems in the same hippocampal regions and layers. Comparisons of marmoset distribution patterns for GABAA, NMDA, L-glutamate and 5-HT1 receptors with those in human hippocampi and those of other primates showed similarities between them. Clear differences in the patterns of alpha 1, M1, M2 and 5-HT2 receptors could be seen between marmoset and human hippocampi, indicating a high degree of species specificity in a presumably "conservative" brain region. More similarities, however, could be found between marmoset and human hippocampi than between those of rat and human brains, especially in relation to 5-HT1 and GABAA receptors and L-glutamate-binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Astroglial responses in photochemically induced focal ischemia of the rat cortex.

This study investigated astroglial responses after focal cerebral ischemia in the rat cortex induced by photothrombosis. Astrocyte activation was studied at various time points by immunocytochemistry for glial fibrillary acidic protein (GFAP) and vimentin (VIM). We found a dual astrocytic response to focal ischemia: In the border zone of the infarct, GFAP-positive astrocytes were present within 2 days and persisted for 10 weeks. These astrocytes additionally expressed VIM. Remote from the ischemic lesion, cortical astrocytes of the entire ipsilateral hemisphere transiently expressed GFAP, but not VIM, beginning on day 3 after photothrombosis. This response had disappeared on day 14. By recording DC potentials, five to seven spreading depressions (SD) could be detected on the cortical surface during the first 2 h after photothrombosis. Treatment with MK801, a non-competitive NMDA-receptor antagonist, completely abolished SD and remote ipsilateral astrocytic activation, while the reaction in the border zone of the infarct remained unchanged. Functionally, persistent astrocytosis around the infarct might be induced by leukocyte-derived cytokines, while NMDA-receptor-mediated SD might cause remote responses.

Animals↗