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Biomedical subjects

L Schweiberer

Publications and source records attributed to L Schweiberer.

At least 163 records · Page 9Linked to original sources
PubMed1991

[Fractures of the humeral head. Conservative and surgical differential therapy].

The Neer classification for fractures of the proximal humerus is a system based on accurate identification of the four major fragments and their relationship to each other. There is a specific type of displaced 4-fragment fracture of the proximal humerus which consists in valgus impaction of the head fragment. This type of fracture is combined with a lower rate of avascular necrosis than that of other displaced 4-fragment fractures. In addition, the outcome is different according to whether a displaced 4-fragment fracture affects the surgical or the anatomical neck. Those through the surgical neck have a much lower rate of avascular necrosis than those through the anatomical neck. Therefore, 4-fragment valgus impacted fractures through the surgical neck should be treated by open reduction and internal fixation rather than by primary hemiarthroplasty in younger patients.

Adult↗
PubMed1991

[The treatment of humeral shaft fractures. Results of a prospective AO multicenter study].

This prospective multicenter study conducted by the German section of the AO International analyzes 302 fractures of the humeral shaft, 170 (56%) of which were operated upon and 132 (44%), treated conservatively. Among those operated upon, 3.5% developed infections and 10% showed paresis of the radial nerve. In contrast, the only complication in the group treated conservatively was pseudarthrosis, in 1 case. However, further analysis revealed that complications were distributed unequally among the centers and the most complications were reported from only a few hospitals. We were able to contact 173 (57%) patients for follow-up. Results of operative and conservative treatment were compared for similar fractures. Both techniques resulted in predominantly good to excellent results. The somewhat inferior results in the group operated upon were explained by the higher percentage of associated local injuries and concomitant injuries to other organs. The results of this study were compared with those of other recent studies, and recommendations were established for the operative and conservative treatment of fractures of the humeral shaft.

Adolescent↗
PubMed1991

[Studies on post-splenectomy infection and immune activation by muramyl peptide. A new concept in the prevention of severe infections].

The existence of the overwhelming postsplenectomy infection syndrome in adults after traumatic splenectomy is discussed controversially. In this study the effects of splenectomy and spleen-preserving operations on outcome of experimental pneumococcemia of the pig were analyzed. Furthermore, the effect of the monocyte activator MTP-PE was assessed. Splenic operations had no influence on the used criteria of sepsis. Pretreatment with MTP-PE protected animals against development of septic leukocytopenia and led to an enhanced bacterial clearance. In addition, mortality of experimental sepsis was significantly decreased. Splenic preservation in adults after posttraumatic splenectomy does not seem to be warranted. On the other hand, the activator of the monocyte-macrophage-system seems to represent an effective regimen to prevent development of sepsis in high-risk patients.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1991

[Surgery of the adrenal glands. Advantages and disadvantages of an anterior versus a posterior approach].

From Jan. 1984 until Oct. 1990 87 adrenalectomies in 75 patients were performed. In 29 patients the transabdominal anterior approach via a transverse upper abdominal laparotomy was carried out for unilateral left (18 pat.) or right adrenalectomy (11 pat.). 46 patients underwent 58 adrenalectomies using the posterior approach as described by Mayor. Using this approach with the patient in prone position, the 11th rib is resected, the pleural reflection identified, the Gerota's fascia incised and the suprarenal space exposed. When the anterior approach was used, blood transfusions were required in 34%. On the other hand, with the dorsal approach, a transfusion was necessary in only 4% of the patients. In 3 of 18 anterior left adrenalectomies a splenectomy was required (17%). The previous was not necessary in any patient having undergone a posterior adrenalectomy. Using the anterior approach postoperative hemorrhage occurred in 7%. No cases of bleeding were observed after posterior adrenalectomy. The average hospital stay was 14.6 days in the transabdominal and 8.5 days in the posterior group. The dorsal approach can only be used in cases in which the tumour is less than 5 cm. For larger of malignant tumours the transabdominal approach is mandatory. In conclusion the posterior adrenalectomy is superior to the anterior and should therefore be employed in appropriate cases.

Adrenal Gland Neoplasms↗
PubMed1991

[Standards for preclinical resuscitation--requirements for efficient therapy and scientific analysis. A prospective study using as an example the combined emergency medical service of the Munich administrative district and capital].

A standardized treatment protocol is essential for scientific evaluation of parameters influencing the outcome and survival of patients who have suffered cardiac arrest in a non-hospital situation. In addition, a standardized therapy algorithm permits effective, time-saving interaction of all members of the emergency team who work together to perform cardiopulmonary resuscitation (CPR) in any emergency outside the hospital. This paper gives the results obtained in 50 patients in whom on-the-spot resuscitation was performed by a specially trained team [emergency medical team (EMT) + on-scene physician] using an ACLS (advanced cardiac life support) protocol modified from the AHA (American Heart Association) standard. Two different algorithms were used one for ventricular fibrillation (VF) and pulseless ventricular tachycardia and one for asystole and pulseless bradycardia. When indicated, countershocks were first administered at a continuous energy level of 360 J, up to three times one after the other. All patients then received epinephrine intratracheally, 2 mg, immediately after intubation. In the case or persisting asystole a further 2-mg dose of epinephrine and then one 5-mg dose were given i.v. in keeping with the ACLS protocol. In the case of persisting VF or pulseless tachycardia we gave one 100-mg dose of lidocaine i.v. and then performed the next countershock at the same energy level. The time the team members actually needed for the single steps of the ACLS protocol was meticulously documented with the aid of a stop watch.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗
PubMed1990

Bone transplantation.

According to one principle of surgery, the transplantation of vital tissue is the best method of reconstructing a defect. Because of absent immunologic reactions, high osteogenic potency, and preserved stability, transplantation of autogenous bone shows the best results. Necrosis of transplanted bone, leading inevitably to absorption and remodeling of the graft, can be avoided if microsurgically vascularized autogenous bone segments are transferred. Disadvantages are the low availability and the necessity of additional operations. As an alternative, deep-frozen allogeneic bone is used. However, this kind of bone shows delayed incorporation based on cellular and humoral immune reactions, and it is also installed into the host bed after overcoming the immune barrier. The risk of microbiological contamination or transmission of unrecognized germs such as HIV is a cause of great expense in bone banking techniques. If one succeeds in reducing (a) the immunologic defense reaction and (b) the risk of infection by sterilization or disinfection without damaging the osteoinductive proteins of bone matrix, the rate of complications can be lowered. Demineralized bone matrix can be used if biomechanical stability is not required. Its ability to induce osteogenesis without a major immune reaction or the risk of transmitting diseases justifies its clinical application. Further intensive research in these areas is unavoidable.

Bone Transplantation↗
PubMed1990

[Pancreatic circulation in experimental biliary pancreatitis].

Measurements of pancreatic micro- and macrocirculation were performed to evaluate the pancreatitis-induced changes. Pigs were anesthetized and ventilated mechanically. Hypotension induced side-effects were avoided by adequate volume replacement. After laparatomy, splenectomy and gastroectomy the animals were enterotomized. Systemic hemodynamic parameters were monitored as well as pancreatic blood flow (Q), which was measured electromagnetically, and arterial and portal-venous blood gases. Pancreatic microcirculatory parameters were observed using fluorescence-videomicroscopy after i.v. administration of FITC dextran 150 and FITC labeled autologous erythrocytes. The pigs were randomly assigned to a control (n = 9) and a pancreatitis group (n = 10), the later being induced by the retrograde infusion of sodium-taurocholate. Systemic and pancreatic macrohemodynamic parameters remained constant in both groups, except for avdO2 and O2-consumption (O2-c) decreasing significantly in the pancreatitis group. At baseline 42% of all capillaries were perfused in both groups. In pancreatitis we detected focal areas with persistent stasis and areas which were continuously perfused. In these areas the portion of capillaries perfused by erythrocytes increased significantly to 67%. This was accompanied by an extravasation of FITC dextran. The finding of an unchanged Q beside reduced O2-c and avdO2 during pancreatitis is explained by the changes in pancreatic microcirculation. Focal stasis was observed beside areas showing typical signs of an acute inflammation: increased macromolecular permeability and capillary recruitment, e.g. oedema and hyperaemia.

Acute Disease↗
PubMed1990

Effects of androgen manipulations on chemically induced colonic tumours and on macroscopically normal colonic mucosa in male Sprague-Dawley rats.

Epidemiological and experimental studies suggest that androgens influence colonic carcinogenesis. We investigated the effects of hormonal manipulations (surgical and chemical castration, hormone substitution) on colonic tumour development, tumour and mucosal histopathology, and epithelial proliferation in macroscopically normal colonic mucosa in male rats, after induction of chemical colon carcinogenesis by subcutaneous injections of azoxymethane (AOM). Chemical castration with cyproterone acetate, but not surgical castration, resulted in increased colonic tumorigenesis, which was accompanied by decreased crypt length, decreased number of cells per crypt, and increased crypt epithelial mitotic index in the right colon. Chemically castrated rats also had crypt hyperplasia and increased numbers of dysplastic foci in the left colon which were not seen with surgical castration. By contrast, rats given testosterone after surgical castration showed decreased colonic tumorigenesis with an increased proportion of tumours in the left colon and lower percentage of tumours with invasion. The grossly normal mucosa of the testosterone-substituted castrated rats showed decreased crypt length in the right colon similar to the other groups of castrated rats, but no significant increase in mitotic index. Our results suggest that the anti-androgenic progestin cyproterone is a potent enhancer of colonic tumorigenesis and epithelial proliferative abnormalities after AOM administration. Exogenous testosterone after castration alters tumour distribution and characteristics and suppresses epithelial proliferative abnormalities. Finally, androgen effects on the colonic mucosa are more prominent in the right than in the left colon, suggesting different influences of hormones on the epithelium of these anatomical sites.

Adenocarcinoma↗
PubMed1990

The effects of sex steroids on colon carcinogenesis.

Numerous reports on colon carcinogenesis reveal gender differences in the incidence and location of tumors. A large number of the presented studies suggest that sex-steroids have a considerable effect on tumorigenesis of the large bowel. To clarify the, so far, not fully understood mechanisms and somewhat conflicting information about the possible hormone action, it is important to discuss two points: first, the reliability of the currently used experimental animal models; and second, what is known concerning the role of sex steroids in colon carcinogenesis.

Adult↗
PubMed1990

[Is there a favorable time for the management of femoral shaft fractures in polytrauma?].

Despite the wide-spread opinion, that early stabilisation of femur fractures in multiply injured patients is of advantage, there are no publications that unambiguously prove this statement. In contrast, primary fracture stabilisation of the femur with concomitant thoracic trauma seems to increase the rate of complications. The biochemical data of the prospective study presented here suggest, that operative stabilisation of femoral fractures imposes an additional trauma on the already compromised organism. The period between days 2 to 4, when the primary activation of humoral and cellular mediators has returned to normal levels, seems to be the best time for osteosyntheses of these fractures. The operation in this period allows intramedullary fixation--the biologically and biomechanically best fixation procedure--with low risk.

Acute-Phase Proteins↗
PubMed1990

[A combination surgical-radiological approach for the treatment of carcinoma of the hepatic duct bifurcation with involvement of both hepatic duct trunks].

The only curative treatment to proximal bile duct cancers with involvement of both hepatic ducts is liver transplantation. A curative resection with wide lateral clearance is limited due to the neighbourhood of vital anatomic structures in the liver hilum. The majority of patients with bile duct cancers is over 60 years of age and due to concomitant disease, they do not fulfill the requirements for liver transplantation. Our treatment strategy in adequate cases is palliative tumor resection and reconstruction of bile passage by sutureless biliodigestive anastomosis as proposed by Rodney Smith. We treated 11 patients with this method, in 5 patients an additive combined radiotherapy by percutaneous radiation and intraluminal after-loading therapy was performed. Our results indicate that this strategy leads to effective palliation in cases provided that only microscopic residual tumor is left in situ (R1-resection). Our observed survival times compare favorably to survival times after liver transplantation (average survival time 11.5 months median survival time 10 months).

Aged↗
PubMed1990

[Arthroscopic cruciate ligament reinsertion and augmentation. Indications--surgical technic].

The advantages of arthroscopic refixation and augmentation of the cruciate ligament in comparison to open methods are conserving innervation of the most important structures of the knee joint, a clear-cut reduction in morbidity, and more rapid rehabilitation of the knee joint. In principle, however, as far as ligament replacement and fixation of the augmented ligament parts are concerned, the technique corresponds to the open method. As the early results refer to a period of 2 years at most, however, it is too soon to report them. Nevertheless, the results of follow-up in our present study are identical to those previously reported by other authors.

Arthroscopes↗
PubMed1990

[Perioperative preventive use of antibiotics in thoracic surgery--results of a controlled randomized study with optocillin].

There seems to be general agreement that antibiotic prophylaxis should be provided for patients undergoing resections of the lung. In order to obtain further information about the extent of resection beyond which this is necessary, and also to establish the type of prophylaxis that is meaningful over the long term, we carried out a controlled study involving two groups of 100 patients each. In the first group, who received minor resections, ultrashort-term prophylaxis was compared with an 0 group. We were able to show that in high-risk patients with prior pulmonary diseases, prophylaxis is indeed meaningful. In the second group of patients undergoing major resections, antibiotic prophylaxis must be provided; a one-day administration suffices, and long-term administration fails to offer any further advantages.

Drug Administration Schedule↗
PubMed1990

Duodenum-preserving resection of the head of the pancreas in treatment of chronic pancreatitis.

Twenty-four patients underwent duodenum-preserving resection of the head of the pancreas for chronic pancreatitis of the head. All patients were reassessed in our follow-up clinic. Comparison with partial duodenopancreatectomy showed that both procedures can alleviate the majority of symptoms. However, duodenum-preserving resection of the head of the pancreas has lower early and late postoperative complication rates. It facilitates occupational rehabilitation, does not alter the patients glucose metabolism, and leaves fewer patients symptomatic in long-term follow-up. A higher rate of recurrence of pancreatitis of the tail is not found. Duodenum-preserving resection of the head of the pancreas is thus considered to be an alternative to partial duodenopancreatectomy in treatment of severe chronic pancreatitis of the head.

Adult↗