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Biomedical subjects

H Becker

Publications and source records attributed to H Becker.

At least 199 records · Page 11Linked to original sources
PubMed1996

[Manually assisted laparoscopic surgery--realistic evolution of the minimally invasive therapy concept? Initial experiences with the "Endohand"].

The essential limitations of laparoscopic procedures--lack of palpation, problematic retrieval of specimen and anastomosis, etc.--are abolished by the hand of the surgeon, which is inserted into the peritoneal cavity through a mini-laparotomy. While holding the pneumoperitoneum, the hand acts as an intelligent instrument performing surgical exploration, exposition of the field of operation, blunt dissection or intracorporal knot-tying. The mini-laparotomy is used to insert conventional instruments and suture material, as well as for specimen retrieval and anastomosis. Our preliminary experience (3x splenectomy, 2x sigmoid colectomy, 1x anterior resection of rectum, 1x proctocolectomy with J-pouch) shows that even extensive laparoscopic operations are accomplished much more simply. The time spent for such procedures is markedly reduced.

Adult↗
PubMed1996

Effects of metoprolol on myocardial beta-adrenoceptors and Gi alpha-proteins in patients with congestive heart failure.

OBJECTIVE: In human heart failure downregulation of beta-adrenoceptors and upregulation of Gi-protein alpha-subunits (Gi alpha) results desensitization of the myocardial beta-adrenergic signal transduction pathway and reduced positive inotropic effects of catecholamines. Metoprolol treatment has been shown to restore the reduced beta-adrenoceptor density in dilated cardiomyopathy. The main objective of the present study was to investigate whether metoprolol also decreases the elevated inhibitory Gi alpha levels in patients suffering from congestive heart failure. METHODS: Total Gi alpha was determined by pertussis toxin-catalysed ADP ribosylation and beta 1- and beta 2-adrenoceptor densities by radioligand binding in right ventricular myocardial biopsies of 18 patients with dilated or ischaemic cardiomyopathy (NYHA II-IV) before and after 3 months of therapy. Nine controls were treated with conventional therapy only [diuretics, digitalis, nitrates, angiotensin-converting enzyme (ACE) inhibitors], and nine received the beta 1-selective blocker metoprolol in addition (mean 98 +/- 12 mg daily). RESULTS: In biopsies from patients treated with metoprolol, Gi alpha significantly decreased to 74% of predrug value and total beta-adrenoceptor increased by a selective increase in beta 1-adrenoceptors (44.7 vs 34.0 fmol mg-1 protein). These effects were accompanied by significantly increased oxygen uptake at the anaerobic threshold (8.65 vs 6.95 ml . kg-1 . min-1). In the control group no significant changes in biochemical and clinical parameters occurred. CONCLUSION: Metoprolol partly reverses Gi alpha-upregulation and beta-adrenoceptor downregulation in heart failure, which might contribute to the clinical improvement of patients treated with beta-blockers.

Adrenergic beta-Antagonists↗
PubMed1996

5-HT agonist-induced changes in peripheral immune cells in healthy volunteers: the impact of personality.

The present study was conducted to investigate the relationship between the serotonergic neurotransmitter system and migration patterns of peripheral lymphocytes. Altogether 40 healthy male volunteers were given either a single dosage of the 5-HT1a-receptor agonist ipsapirone (10 mg) or a placebo (n = 20 each) in a double-blind randomized trial. Blood samples were drawn 55, 90 and 110 min after drug intake (baseline) and were analyzed for the number of peripheral lymphocytes. Furthermore, saliva samples were obtained at 13 defined time points which were analyzed for cortisol concentrations. Personality traits impulsivity, psychoticism and boredom susceptibility) were measured by questionnaires to investigate personality related differences in levels of serotonergic responsiveness. Analyses of covariance indicated that ipsapirone leads to highly significant reductions of peripheral CD4+ cells (T-helper/inducer-cells). This was significantly correlated to the ipsapirone-induced release of cortisol in a time-dependent manner. Furthermore, subjects scoring high on impulsivity, psychoticism and boredom susceptibility could be identified as being more responsive to the 5-HT agonist, indicated by their larger reduction in T-helper cells and greater cortisol release. This was hypothesized to be either due to their subsensitivity of presynaptic or supersensitivity of postsynaptic 5-HT1a-receptors.

Adult↗
PubMed1996

[Possibilities and limitations of CT angiography in comparison to DSA in intracranial aneurysm].

PURPOSE: The purpose of this study was to determine the value of CT angiography in the detection of intracranial aneurysms and to discuss its qualities compared with DSA. METHODS: 26 patients with subarachnoid bleeding confirmed by unenhanced CT or lumbar puncture were examined with CT angiography. In 23 of these patients results of DSA were available. RESULTS: In 21 cases 30 aneurysms were found with DSA, whereas in two cases there were no aneurysms. The size of the aneurysms was between 3 and 36 mm. With CT angiography two small 3 mm aneurysms were not detected. In three patients with vasospasms the diagnosis was primarily confirmed by CT angiography. The sizes measured by CTA and DSA were approximately the same. CONCLUSION: Because of the limited spatial resolution small aneurysms (< 5 mm) could not be diagnosed in CTA. Definitive exclusion of aneurysms is therefore not possible. Aneurysms larger than 5 mm are reliably diagnosed. CTA is indicated if identification of the bleeding aneurysm is sufficient for further patient management.

Adult↗
PubMed1996

Using hyaluronic acid to create a fetal-like environment in vitro.

The fetal wound healing matrix is exceptionally rich in hyaluronic acid (HA). Fetal wounds heal without scarring or contraction. Noting these observations, we cultured adult dermal explants in the presence of various concentrations of medical-grade HA in vitro. In the presence of HA, fibroblasts migrated from the dermal explant and multiplied more rapidly than control explants. Subsequently, sterile toothpicks were used to disrupt (wound) fibroblast monolayers mechanically and the rate of closure was monitored. Cells cultivated in the presence of 5 mg/ml of exogenous HA changed in morphology and closed the wound more quickly than control cultures. Cells surrounding the wound extended numerous podalic processes and showed increased interdigitation. The effect of HA on cell proliferation is usually discussed in terms of the mechanical effects HA exerts on cells and the extracellular matrix. The physiological effect of HA may lie in its ability to act as an accessory receptor in cooperative ligand-binding pathways. For example, HA may bind growth and/or other factors, and thereby increase the effective concentration of these factors at the cell surface.

Aged↗
PubMed1996

Do saline breast implants harbor microbes?

Recent anecdotal reports have indicated that a high percentage of saline implants harbor dangerous microbes. These reports have caused considerable alarm and fear to saline implant recipients. Reports in the literature of microbial growth in saline implants are infrequent. The expander implant offers an ideal opportunity to study the internal milieu of saline implants in vivo. The study shows that, if used properly, saline implants do not become infected. In this study, 45 expander implants were studied under clinical conditions. No evidence of microbial contamination of the saline was found.

Breast Implants↗
PubMed1996

Effect of Xenon.

Explore the source record for details and available documents.

Acetazolamide↗
PubMed1996

[Laparoscopic diagnosis and therapy of closed traumatic diaphragmatic rupture].

Diagnosis of blunt diaphragmatic rupture is still a challenging problem. This injury is generally treated by direct closure of the defect via a laparotomy or a thoracotomy. As it occurs frequently in severely traumatized patients, we wondered whether those patients could benefit from the well-known advantages of minimally invasive surgery. We report the records of two patients who underwent laparoscopy for blunt diaphragmatic hernia. In both patients, the hernia was laparoscopically closed without opening the abdomen. We did not see any intra- or postoperative complications related to minimally invasive surgery; the postoperative recovery was impressively short. Taking into account the fact that diaphragmatic ruptures are frequently misdiagnosed, we recommend laparoscopy as a useful tool in cases where these injuries may be suspected. In selected patients, primary closure of the defect may be achieved within the same laparoscopy so that laparotomy can be avoided.

Adult↗
PubMed1996

Stimulation of neutropoiesis by a special standardized mistletoe preparation after cyclophosphamide chemotherapy in mice.

Lektinol, is a special mistletoe preparation (SMP) with immunostimulatory activity, standardized with respect to bioactive mistletoe lectin, one of the most active components of mistletoe. In the present study, stimulation of leukopoiesis by SMP was investigated in mice after induction of myelosuppression by the cytostatic agent cyclophosphamide (CP). Under the experimental conditions described, CP induced severe leukopenia followed by a recovery phase where leukopoiesis was distinctly enhanced in mice treated additionally with SMP at daily intravenous doses in a range of 30 to 5000 microliters/kg body weight. This phenomenon was mainly due to a stimulation of granulopoiesis resulting in a stronger increase of metamyelocyte and mature neutrophil counts in the peripheral blood.

Animals↗
PubMed1995

[Surgery of colorectal carcinoma].

Surgery is the primary mode of therapy for colonic and rectal cancer. The principles of surgery are: laparotomy for staging, wide en bloc resection of the primary tumor and lymphadenectomy for staging as well as possible therapeutic benefit. Reasonable efforts should be made intraoperatively to prevent intraluminal and intraperitoneal spread. Resection of metastases can prolong survival in stage D patients confined to the liver. Dukes C colon cancer patients should receive multiagent chemotherapy. There is no well defined role for radiation therapy as adjuvant treatment in colon cancer. Local failure pattern and treatment strategies are different for cancer of the rectum. Surgery remains the mainstay of treatment for all lesions; other modalities are adjunctive. Lesions within 5 cm of the anal verge usually require abdominoperineal resection, while the other are treated with a low anterior resection. New techniques are emerging to preserve the anal sphincter and gastrointestinal continuity, and these are being tested to determine if adequate tumor control is obtained.

Chemotherapy, Adjuvant↗
PubMed1995

[Nasal continuous positive airway pressure (nCPAP) therapy in obstructive sleep breathing disorders].

The therapeutic efficacy and the incidence of significant side effects of nasal continuous positive airway pressure (nCPAP) treatment was investigated in 1140 patients with sleep-related apnoea (1089 men, 51 women; mean age 53.2 +/- 9.2 [16-84] years). All had been treated for the condition with nCPAP at the Marburg University Medical Polyclinic between 1986 and 1992. The mean number of attacks of apnoea and/or hypopnoea per hour of sleep ("respiratory disturbance index", RDI) was 45.8 +/- 25.6 before treatment and 3.5 +/- 4.8 under nCPAP. 21.1% of patients had an apnoea index of no more than 10/h. 11.6% an RDI of no more than 15/h. The average airway pressure was 8.7 (3-18) cm H2O. The treatment was successful in 1023 patients and these decided to continue the treatment long-term. The RDI could not be lowered under 10/h in 63 patients, while 4 patients declined ambulant treatment despite the demonstrated efficacy of nCPAP. Three patients developed acute left ventricular failure in the initial phase of the treatment, while in another 16 patients long-persisting central hypoventilation was shown to occur. These data show that treatment with nCPAP can be employed for all degrees of severity of obstructive sleep apnoea. However, because of the potentially life-threatening side effects, the introduction of the treatment must be undertaken in the sleep laboratory under continuous monitoring.

Adolescent↗
PubMed1995

Randomized controlled multicentre study of the prevention of complications by octreotide in patients undergoing surgery for chronic pancreatitis.

A randomized double-blind placebo-controlled multicentre trial was carried out in 247 patients undergoing major elective surgery for chronic pancreatitis to clarify whether the perioperative application of octreotide prevents postoperative complications. Eleven complications were defined, including death, anastomotic leakage, pancreatic fistula, abscess, fluid collection, shock, sepsis, bleeding, pulmonary insufficiency, renal insufficiency and postoperative pancreatitis. A total of 124 patients underwent pancreatic head resection, 55 left resection, 61 pancreaticojejunostomy and seven had other procedures. The overall mortality rate was 1.2 per cent (octreotide group 1.6 per cent, placebo group 0.8 per cent [corrected] (P not significant)). The postoperative complication rate in the octreotide group was 16.4 per cent (20 of 122 patients) and in the placebo group 29.6 per cent (37 of 125) (P < 0.007). The perioperative application of octreotide substantially reduces the risk of postoperative complications in patients undergoing major pancreatic surgery for chronic pancreatitis.

Adult↗
PubMed1995

Hypertrophic cardiomyopathy: a desensitized cardiac beta-adrenergic system in the presence of normal plasma catecholamine concentrations.

Only few data are available concerning the biochemical and functional state of the beta-adrenergic system in hypertrophied human myocardium. The present study was to investigate the myocardial beta-adrenergic signal transduction system in hypertrophic obstructive cardiomyopathy (HOCM). Thin myocardial strips were prepared from surgically excised, septal myocardium from 7 patients with HOCM and their force of contraction was measured in vitro. The positive inotropic effects of calcium and dihydro-ouabain, both acting independently of beta-adrenoceptors and cAMP, were similar in these preparations to those, previously published, seen with nonfailing myocardium. In contrast, the beta-adrenoceptor agonist isoprenaline and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) had reduced positive inotropic effects. Their EC50-values were about 10 fold higher than the respective EC50-values published for nonfailing myocardium. The positive inotropic potencies of isoprenaline and IBMX were reduced in HOCM by as much as they were in the additionally investigated myocardium from 6 patients with severe mitral regurgitation (MR, NYHA III). In order to clarify whether the functional alterations are related to changes in the beta-adrenoceptors, beta-adrenoceptor density and beta 1: beta 2-adrenoceptor subtype distribution were determined in the same myocardium using 125I-Iodocyanopindolol saturation binding. Myocardial beta-adrenoceptor density was reduced to 68% in HOCM and to 56% in MR compared to nonfailing myocardium controls (NF: 64.8 +/- 6.5 fmol/mg protein). In HOCM, this reduction was due to a selective down regulation of beta 1-adrenoceptors (24.9 +/- 3.7 fmol/mg protein vs NF: 46.4 +/- 6.8 fmol/mg protein, P < 0.05), whereas beta 2-adrenoceptor density was unchanged (19.0 +/- 1.9 fmol/mg protein vs NF: 18.4 +/- 3.3 fmol/mg protein, n.s.). In MR both beta-adrenoceptor subtypes were reduced (beta 1: 26.9 +/- 1.4 fmol/mg protein, beta 2: 9.6 +/- 1.7 fmol/mg protein; both P < 0.05 vs NF). Electrochemically determined plasma catecholamine levels were elevated in MR. However, plasma catecholamine levels were normal or slightly below normal in HOCM. In summary, myocardial beta-adrenoceptors are downregulated and their function is impaired in HOCM. This desensitization is not caused by a negative feedback regulation due to increased plasma catecholamines. The present results show that the desensitizations of the beta-adrenergic system associated with HOCM has characteristics that indicate a major deviation in its development from that of the beta-adrenergic desensitization previously described to occur in congestive heart failure.

Adult↗
PubMed1995

The effects of prostacyclin on gastric intramucosal pH in patients with septic shock.

OBJECTIVE: To investigate whether infusing prostacyclin (PGI2) in patients with septic shock improves splanchnic oxygenation as assessed by gastric intramucosal pH (pHi). DESIGN: Interventional clinical study. SETTING: Surgical ICU in a university hospital. PATIENTS: 16 consecutive patients with septic shock according to the criteria of the ACCP/SCCM consensus conference all requiring norepinephrine to maintain arterial blood pressure. INTERVENTIONS: All patients received PGI2 (10 ng/kg x min) after no further increase in oxygen delivery could be obtained by volume expansion, red cell transfusion and dobutamine infusion. The results were compared with those before and after conventional resuscitation. The patients received continuous PGI2 infusion for 33-32 days. MEASUREMENTS AND RESULTS: O2 uptake was measured directly in the respiratory gases, pHi was determined by tonometry. Baseline O2 delivery, O2 uptake and pHi were 466 +/- 122 ml/min.m2, 158 +/- 38 ml/min.m2, and 7.29 +/- 0.09, respectively. While O2 uptake remained unchanged, infusing PGI2 increased O2 delivery (from 610 +/- 140 to 682 +/- 155 ml/min.m2, p < 0.01) and pHi (from 7.32 +/- 0.09 to 7.38 +/- 0.08, p < 0.001) beyond the values obtained by conventional resuscitation. While 9 of 11 patients with final pHi > 7.35 survived, all patients with final pHi < 7.35 died (p < 0.01). CONCLUSIONS: Infusing PGI2 in patients with septic shock increases pHi probably by enhancing blood flow to the splanchnic bed and thereby improves splanchnic oxygenation even when conventional resuscitation goals have been achieved.

Adult↗
PubMed1995

[Quantification of relevant measurements of the petrous bone with computerized tomography before cochlear implant operation].

In this investigation the following anatomical measurements of the petrous bone preceding cochlear implant were evaluated using computed tomography (CT): the width of the basal coil of the cochlea, the thickness of the promontory, the distance between the sigmoid sinus and the posterior wall of the external auditory canal and the thickness of the squamous part of the temporal bone in the area of operation. Initially it was necessary to ascertain how accurately CT represents the anatomical structures of the petrous bone. The procedure of CT investigation in adult patients was simulated using the base of a skull. The CT plane in which the above mentioned measurements preceding cochlear implant can be made was represented and measurements were taken. Subsequently the same plane in CT was represented macroscopically with a specially developed method. The results show that anatomical structures measured in CT are magnified by 5% in contrast to the original. This magnification is presumably attributable to the computing of connective tissue which is adjacent to bone and the incapacity of CT to image structures of different density in the same voxel. In the second part of this investigation we evaluated 66 preoperative CT's of patients who were given a cochlear implant. The results must be adjusted by 5% to allow for this error in magnification. In conclusion a preoperative radiologic evaluation of the anatomical structures relevant to cochlear implant is without doubt tenable. Also the negligible difference between CT and the anatomical original requires no operative consequences. Because cochleostomy is carried out with a diamond burr of 1 mm diameter, a tenth of a millimeter is negligible according to our experience.

Adolescent↗