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Biomedical subjects

P Henke

Publications and source records attributed to P Henke.

10 recordsLinked to original sources
PubMed1999

An in-vitro evaluation of aortic arch vessel perfusion characteristics comparing single versus multiple stream aortic cannulae.

OBJECTIVE: During extracorporeal circulation design and orientation of aortic cannulae tips mainly determine flow pattern in the aortic arch and arch vessels which is the objective of this in vitro study, comparing single versus multiple stream cannulae. METHODS: In an aortic arch glass model, jet streams of 21-24 French aortic cannulae which were inserted in the ascending aorta were directed alternatively at the different arch vessels. Flows and pressures in the arch vessels were measured at pump flows of 3-6 l/min. RESULTS: With optimal orientation of the jet stream in the aortic arch, no preferential flow in the arch vessels was seen. In the single jet stream aortic cannulae group a significant parallel increase in flow and pressure in the jet streamed arch vessels compared to the non-jet streamed arch vessels occurred (P < 0.05). With the jet stream directed on vessel 2 (left carotid vessel) there was a significant pressure and flow difference comparing the two non-jet streamed vessels with each other (P < 0.03). In the single stream 24 French cannulae the highest vessel pressure of 168 mmHg and an increase in flow of 186 ml/min was measured in the jet streamed left carotid artery at 6 l/min pump flow. The multiple stream cannulae provoked the highest vessel pressure of 106 mmHg in the corresponding jet streamed vessel and an increase in flow of 20 ml/min. CONCLUSION: Tip design of aortic cannulae and the orientation of its jet stream are potential sources of remarkable imbalance of arch vessel perfusion especially with single jet stream cannulae. These effects are more pronounced with single jet stream cannulae. These results may have important clinical implications regarding perfusion of arch vessels during extracorporeal circulation.

Aorta, Thoracic↗
PubMed1998

Endoscopic ultrasound-guided, 18-gauge, fine needle aspiration biopsy of the pancreas using a 2.8 mm channel convex array echoendoscope.

BACKGROUND: Previous studies have reported on endoscopic ultrasound-guided, fine needle aspiration biopsy using 22- to 25-gauge needles. We evaluated the histologic and cytologic yield of endoscopic ultrasound-guided, fine needle aspiration biopsy of the pancreas using an 18-gauge, Menghini-type core needle. METHODS: Fine needle aspiration biopsy was performed in conjunction with a prototype 2.8 mm channel convex array echoendoscope. The core specimen was placed in formalin for cell block, and residual material was expelled on slides for cytology. Definitive diagnosis was established by surgery or clinical follow-up. RESULTS: Of 45 patients who underwent fine needle aspiration biopsy, the needle failed to penetrate indurated pancreatic lesions in five. An average of 2.6 passes were performed in the remaining patients. Sufficient material for a histologic and/or cytologic diagnosis was obtained in 40 patients (histologic and cytologic yield of 68% and 75%, respectively). Combining the results of histology and cytology, the sensitivity and specificity for detection of malignancy was 76% and 100%, respectively. Histology confirmed the cytologic findings in 35 patients, providing additional tissue specific information. In three cases histology established a diagnosis of malignancy where cytology was not conclusively malignant. However, in three cases of surgically confirmed malignancy histology failed to detect malignancy, whereas cytology showed suspicious or malignant cells. The sensitivity of histology and cytology alone in detecting malignancy was 53% and 70%, respectively. Mild pancreatitis occurred after pancreatic fine needle aspiration biopsy in one patient. CONCLUSION: Core specimens for histology can be safely obtained using an 18-gauge needle. Histology provides tissue-specific information that complements cytology, but histology is less sensitive than cytology in detecting malignancy.

Adenocarcinoma↗
PubMed1992

[Liver dystrophy in disseminated herpes simplex infection in pregnancy].

The reported case of an unsuccessful treatment with acyclovir of herpes simplex virus hepatitis in a young patient, during pregnancy, demonstrates the necessity of an early diagnosis with the consequence of an early therapy. If serum antibodies are not evident, the presumptive diagnosis is based upon the histological demonstration of inclusion bodies in liver biopsy specimens. With the DNA-in-situ hybridisation technique, differentiation of the type of virus infection is possible in a short time. Hence, consideration should be taken that a biopsy of the liver should be done before the coagulation system breaks down due to hepatic necrosis. The risk of the liver biopsy seems to be low compared with the high morbidity and mortality of mother and child in systemic herpes simplex virus hepatitis.

Adult↗
PubMed1990

Reproducibility of isokinetic muscle strength measurements in normal and arthritic individuals.

The serial reproducibility of an individual's isokinetic torque was assessed in order to establish a reliable baseline value for future comparison. Thirty-two controls and twenty arthritic patients were tested for their peak isokinetic torque on knee flexion and extension and hip flexion at three velocities on five occasions, at fortnightly intervals. The first test was found to provide a reliable baseline for controls and subjects who could generate a peak torque of 54 Newton meters (Nm) or more. The second test was found to be more representative of the series for groups containing weaker subjects. Variation related to torque: for subjects who generate a peak torque of 54 Nm or more, a range of +/- 20% accommodates the variability of 95% of tests. We conclude that a +/- 20% range applied to either the first or second test, depending on the nature of the group to be studied, serves as a representative baseline value.

Aged↗
PubMed1989

[Individualization of chemotherapy through in vitro predictive determination of the cytostatic sensitivity of malignant tumors].

An in-vitro test was developed for predicting the efficacy of anti-tumour chemotherapy. Cell cultures were grown from freshly removed tumours and it was then demonstrated by DNA cytophotometry and immuno-cyto-chemistry whether the growing tumour cells corresponded to those of the original tumour cells. Several cytostatic agents were then tested for their efficacy of inhibiting growth at clinically customary dosage. Growing cell cultures were established in 306 of 413 submitted tumours (74%). They responded quite differently to the various drugs that were tried. The clinical course in 94 cases was observed for minimally four and a mean of eight months to obtain an in-vitro to in-vivo correlation of response, with 178 individual correlations. A discrepancy was recorded in 16% of cases, a false-positive in-vitro sensitivity result was 3.6 times more frequently associated with an in vivo resistance than the reverse. Concordance between test results and clinical tumour response occurred in 84%. The monolayer proliferation assay correctly indicated resistance in 93.8%, sensitivity in 72.8%.

Antineoplastic Agents↗
PubMed1988

Immunohistochemistry (S 100, KL 1) and human papillomavirus DNA hybridization on morbus Bowen and bowenoid papulosis.

In this study 55 paraffin embedded samples defined as Bowen's disease or bowenoid papulosis were investigated with antibodies against S 100 protein and keratins (KL 1). S 100-positive cells were quantified and related to defined section area of the epidermal compartment by computer-assisted image analysis. The density of S 100-positive cells was compared with normal skin and was particularly related to growth patterns and keratinization of the different lesions under study. S 100-positive dendritic cells were found to be reduced overall in bowenoid lesions when compared with normal skin. Lesions with high counts of S 100-positive dendritic cells most frequently showed a solitary growth pattern with highly conserved architecture and differentiation and no tendency to stromal invasion. In contrast, cases with low counts of S 100-positive cells very often showed multifocal development, a high degree of architectural disturbance and dedifferentiation. In this group, stromal invasion (cases of invasive carcinoma associated with Bowen's disease) was seen more often. Interestingly, this latter group of cases also revealed a peculiar keratin pattern. Frequently, the basal cell layer was decorated with KL 1 antibody, which usually recognizes only suprabasaly located keratinocytes. No differences between Bowen's disease and bowenoid papulosis were found in terms of densities of S 100-positive dendritic cells and keratin pattern. In our experience, extragenital Bowen's disease and genital Bowen's disease can not be distinguished on purely morphological grounds or with the immunocytochemical approach presented here. Interestingly, when employing in situ hybridization with HPV 16 probes three of seven samples of genital Bowen's disease harboured HPV 16 DNA, whereas six cases of extragenital disease were negative.

Adult↗
PubMed1980

[The physician's responsibility at the intensive care unit].

The relation between physician and patient--particularly at the intensive care unit--is interpreted by the structure of responsibility. At the same time we try to answer the question whether there is a criterion to set a limit on the physician's duty.

Decision Making↗