Antivirally protective cytotoxic T cell memory to lymphocytic choriomeningitis virus is governed by persisting antigen.

The basis of antiviral protection by memory cytotoxic T lymphocytes (CTL) was investigated in vivo and in vitro using lymphocytic choriomeningitis virus (LCMV) and recombinant vaccinia viruses expressing the LCMV-glycoprotein (vacc-GP) or -nucleoprotein (vacc-NP). The widely replicating LCMV with a tendency to persist induced solid long-term protective memory. The poorly replicating vaccinia recombinant viruses revealed in the vaccinated host that the antiviral capacity of the secondary immune T cell response and the protection against lethal LCM was dependent upon the immunizing antigen and its dose. Protection against lethal choriomeningitis is less sensitive to assess memory because it depends upon high levels of CTL precursors (p) and/or on an activated state of memory CTL. In contrast, antiviral protection measured as the capacity of the primed host to reduce virus titers after challenge infection correlated with elevated CTLp frequencies after immunization with live LCMV or recombinant vaccinia virus-expressing the major LCMV epitope. CTLp frequencies were constantly increased up to 70 d for LCMV immune mice, but rapidly decreased a few weeks after immunization with low dose vaccinia recombinant virus. For example, mice primed with 2 x 10(6) plaque-forming units (PFU) of vacc-NP, or 2 x 10(2) PFU, or 2 x 10(6) PFU of vacc-GP were antivirally protected on day 7 but not after day 30 when CTLp could not be measured any longer in vitro. However, greater priming doses of vacc-NP (10(4) or 2 x 10(6) PFU) as well as LCMV (2 x 10(2) PFU) induced elevated levels of CTLp and antiviral protection for 60 d or longer. Adoptive transfer experiments of immune spleen cells into syngeneic recipients without addition of antigen demonstrated that maintenance of the antiviral protective capacity of the transferred cells depended on the presence of viral antigen. Thus, antiviral protection by memory CTL may be rather short-lived since it is based on activated T cells continuously stimulated by persisting antigen. This is best achieved by high immunizing antigen doses yielded either by widely replicating viruses or high doses of poorly replicating recombinant vaccines.

Islets of Langerhans are protected from inflammatory cell recruitment during reperfusion of rat pancreas grafts.

BACKGROUND: Ischemia/reperfusion (I/R) injury plays a pivotal role in the development of graft pancreatitis, with ischemia time representing one of its crucial factors. However, it is unclear, whether exocrine and endocrine tissue experience similar inflammatory responses during pancreas transplantation (PTx). This study evaluated inflammatory susceptibilities of islets of Langerhans (ILH) and exocrine tissue after different preservation periods during early reperfusion. METHODS: PTx was performed in rats following 2 h (2h-I) or 18 h (18h-I) preservation. Leukocyte-endothelial cell interactions (LEI) were analyzed in venules of acinar tissue and ILH in vivo over 2 h reperfusion. Nontransplanted animals served as controls. Tissue samples were analyzed by histomorphometry. RESULTS: In exocrine venules leukocyte rolling predominated in the 2h-I group. In the 18h-I group, additionally, high numbers of adherent leukocytes were found. Histology revealed significant edema formation and leukocyte extravasation in the 18h-I group. Notably, LEI in postcapillary venules of ILH were significantly lower. Leukocyte rolling was only moderately enhanced and few leukocytes were found adherent. Histology revealed minor leukocyte extravasation. CONCLUSION: Ischemia time contributes decisively to the extent of the I/R-injury in PTx. However, ILH have a significantly lower susceptibility towards I/R, even when inflammatory reactions in adjacent exocrine tissue are evident.

Pancreatic microcirculatory changes in experimental pancreatitis of graded severity in the rat.

BACKGROUND: A technique with two complementary methods, intravital microscopy (IVM) and diffuse reflectance spectroscopy (DRS), was developed to analyze pancreatic tissue perfusion. METHODS: After initial in vivo and in vitro validation of the techniques, we studied pancreatic microcirculation in models of mild, moderate, and severe pancreatitis. Anesthetized Sprague-Dawley rats were randomly allocated to the three models or to serve as controls. Stable systemic hemodynamic parameters were maintained with normal saline solution infusion. Exocrine capillary perfusion was assessed by IVM; hemoglobin oxygenation and hemoglobin content were measured by DRS. RESULTS: Capillary perfusion in mild pancreatitis initially increased significantly at 30 minutes to 155% +/- 38% of baseline values but returned to baseline within 3 hours. Hemoglobin content and oxygen saturation remained stable. In moderate and severe pancreatitis capillary perfusion significantly decreased versus the control group to 12% +/- 6% and 6% (range, 0% to 14%) of baseline values, respectively, at 6 hours. Oxygen saturation decreased significantly in moderate pancreatitis from 48.5% +/- 2.3% to 41.6% +/- 3.5% (p < 0.05) and in severe pancreatitis from 47.2% +/- 1.5% to 38.9% +/- 0.5% (p < 0.05), whereas hemoglobin content did not change. CONCLUSIONS: We conclude that (1) IVM and DRS provide both unique and complementary data on tissue perfusion of the pancreas, (2) that moderate and severe experimental pancreatitis are accompanied by progressive tissue ischemia, and (3) that significant stasis (decreased perfusion) and decreased oxygen saturation occur whereas generalized vasoconstriction (decreased hemoglobin levels) was not found. In contrast, mild experimental pancreatitis was accompanied by initial hyperperfusion and normal oxygen delivery was maintained.

Lesion patterns of vasoactive intestinal polypeptide-containing neurons in the myenteric plexus induced by clamping or transsection of rat jejunum.

The acute reactions of vasoactive intestinal polypeptide (VIP)-containing neurons in the myenteric plexus of the rat jejunum in response to circumferential clamping or transection/reanastomosis were evaluated in a detailed time course of up to ten days. Whereas in sham-operated controls VIP immunostaining was confined exclusively to varicose fibers, either clamping or transection induced the appearance of strongly VIP-immunoreactive beaded neuronal processes and neuronal perikarya in the oral part of the lesion one day postoperatively. After five days strongly immunostained varicose fibers orientated in the longitudinal axis of the gut towards the lesion reappeared suggestive of the onset of regenerative processes.

[Therapeutic procedure in "incidentaloma" of the adrenal glands]. / Therapeutisches Vorgehen beim "Incidentalom" der Nebenniere.

Incidentally discovered adrenal masses are a therapeutic challenge. As benign lesions, like hyperplasias and adenomas, are much more common than malignant ones, an approach is needed, which incidental discovered mass should be removed. If the tumor is hormonally active or the lesion has a diameter of more than 3 cm, we advice surgery. The smaller mass should have a careful follow-up.

[Chronic fistulating wound infection after Lichtenstein repair of inguinal hernia, caused by a small colony variant of Staphylococcus aureus]. / Chronisch fistelnde Wundinfektion nach Lichtensteinreparation einer Leistenhernie, verursacht durch eine Small-colony-Variante von Staphylococcus aureus.

We report a case of chronic wound infection (abscess, fistula) after a Lichtenstein repair of inguinal hernia. After surgical treatment (mesh explantation), a small-colony variant (SCV) of Staphylococcus aureus was cultured microbiologically. SCV represent subpopulations of Staphylococcus aureus which are associated with chronic infections and which respond poorly to usual treatment regimes. In this case surgery and specific antibiotic treatment with flucloxacillin and rifampicin were successful.

[A combination surgical-radiological approach for the treatment of carcinoma of the hepatic duct bifurcation with involvement of both hepatic duct trunks]. / Ein kombiniert chirurgisch-radiologisches Konzept zur Behandlung des Hepaticusgabelcarcinoms mit Befall beider Hepaticusstämme.

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).

Micro-targeting: high efficiency gene transfer using a novel approach for the acceleration of micro-projectiles.

We have constructed a novel micro-projectile accelerating system for efficient gene transfer into cells in situ that avoids binding DNA to micro-projectiles and keeps the DNA in solution. Further, instead of a macro-projectile (or the equivalent), it accelerates the particles in a Bernoulli air stream. The micro-targeting approach directs highly dispersed particles to sites with diameters as little as 0.15 mm, allowing precise aiming to restricted tissues. The system is physically flexible and should therefore be adaptable to different tissues and species. Transient expression of the Escherichia coli beta-glucuronidase gene in immature wheat embryo scutella was obtained at a frequency of up to 3% of the treated cells in the surface layer. In tobacco SR1, we achieved many transgenic plants, and the efficiency of stable transformation with the neomycin phosphotransferase (NPTII) gene was approximately 10(-3) per exposed cell.

[Diagnosis of acute appendicitis. Is physical examination enough to reach a surgical decision?]. / Diagnostik der akuten Appendizitis. Reicht die körperliche Untersuchung zur OP-Entscheidung aus?

In the large majority of cases, acute appendicitis can be diagnosed on the basis of the medical history and the patient's symptoms. Urine should be drawn from every patient for urinstix and bacteriological testing, as well as blood for a blood count, electrolytes and coagulation parameters. A US should be performed, in particular to exclude possible other diagnoses. Women should be examined by a gynecologist. Once the diagnosis has been established, the patient must be sent for surgery without delay. Should there be reason for doubt, further diagnostic measures (in particular CT) should be carried out as permitted by the urgency of the case. In life-threatening situations, laparoscopy should be done immediately, and preparations made for laparotomy should this be necessary. If the symptoms are such that a wait-and-see attitude is justified, continued observation and follow-up examinations are recommended. The diagnosis of acute appendicitis can be difficult, and every patient who rouses relevant suspicion, should be seen by a surgeon.

Vascular mechanisms to induce acute pancreatitis.

Vascular mechanisms are not standard tools to induce acute pancreatitis. They are used for special purposes to investigate the pathophysiologic significance of circulatory changes in acute pancreatitis. Because of the rich collateral network, occlusion of the main pancreatic arteries induces no pathological change. Complete occlusion of the venous outflow induces hemorrhagic necrosis of the pancreas, disturbances of the microcirculation, edema and focal parenchymal necrosis as in acute pancreatitis. In the last model, pancreatic and systemic alterations can be examined.

[Characterization of low molecular weight zinc species in normal commercial vegetable foodstuffs]. / Charakterisierung niedermolekularer Zinkspezies in handelsüblichen pflanzlichen Lebensmitteln.

In six different ordinary vegetables, namely kohlrabi, Chinese cabbage, chard, leak, spinach and Jerusalem artichoke, zinc was mainly found as low molecular weight species. In the present study, these important zinc compounds are further investigated. The determinations of the metal are performed by ET-AAS. The zinc complexes of all vegetables are anionic at pH 8.0 and show similar elution behaviour in gel permeation and anion exchange chromatography. Consequently, a great resemblance in structure between the low molecular weight zinc species from the different vegetables can be supposed. Exemplary, the zinc complexes of kohlrabi and Chinese cabbage are further examined. In more purified samples of these vegetables compared to zinc neither stoichiometric amounts of free protein amino acids nor nicotianamine, free malic acid, citric acid or phytic acid have been detected. Mainly glutamic acid is found in molar excess to zinc after acid hydrolysis in both cases. The cysteine contents of both zinc-binding fractions are very low. Conclusively, the well-known gamma-glutamylcysteinyl-glycines (phytochelatines) can not be responsible for the bonding of zinc in both ordinary vegetables. We suppose that zinc in kohlrabi and Chinese cabbage is bound to a glutamic acid derivative unknown as yet, possibly a malic acid ester.

[Prevention of thrombosis in surgery of the extremities. Physical methods in thrombosis prevention]. / Thromboseprophylaxe in der Extremitätenchirurgie. Physikalische Methoden der Thromboseprophylaxe.

Physical therapy procedures for the prophylaxis of thrombosis are part of basic medical therapy. Their effect has been documented by numerous individual observations, even though no prospective studies are available. Since the inconvenience to the patient is minor, they should be implemented in all surgical patients. In the case of patients at risk of thrombosis such as in orthopedic surgery, the effect of such procedures is not sufficient. In this case physical therapy procedures can only supplement the medical prophylaxis of thrombosis. The effectiveness of technically more complex physical procedures has been documented in small studies, but due to the high technical and personnel costs, the application is restricted.

[Perioperative standards for prevention of anastomotic insufficiency]. / Perioperative Standards zur Vermeidung von Anastomoseninsuffizienzen.

Anastomotic leakage is a major cause of morbidity and mortality in gastrointestinal surgery. Its incidence varies in the different segments of the GI tract being highest in the distal rectum. The rate of anastomotic leakages was reduced considerably within the last 20 years. Perioperative measures have contributed to this reduction in addition to improvements and standardization in operative technique. Perioperative nutrition, perioperative antibiotic prophylaxis and mechanical bowel preparation are widely used in colorectal surgery. Therefore they can be considered as standards. High-caloric parenteral feeding is used commonly perioperative. Its efficiency to reduce postoperative septic complications has been proven until now only for malnourished patients. The aim of perioperative antibiotic prophylaxis is to reduce the bacterial count after intraoperative contamination. Therefore tissue levels must be in the therapeutic range to cover for the expected bacteria. The efficiency to reduce postoperative wound infection has been proven, however the influence on the rate of anastomotic leakages is still controversial. Mechanical bowel preparation can reduce the bowel load but not bacterial concentration inside the bowel. Orthograde lavage with polyethylenglycol solution is feasible unless bowel obstruction is present, but its influence on anastomotic healing is still under discussion. Although all of these procedures are widely used, their influence on anastomotic healing has still to be proven by prospective, controlled trials.

Optimisation of sample pre-treatment in the HG-AAS selenium analysis.

A fast and accurate method of pre-treatment for biological materials in the hydride generation-atomic absorption spectroscopy (HG-AAS) selenium determination is described. All procedures of sample pre-treatment were performed in closed-vessels in a microwave oven. After sample decomposition using a HNO3/H2O2 mixture, the pre-reduction and a 'denitrification' step (reduction of interfering nitrogen intermediates) with amidosulfuric acid were combined. Hence, analysis time and the risk of element losses or the emergence of possible contamination are minimised.

[Surgery of the adrenal glands. Advantages and disadvantages of an anterior versus a posterior approach]. / Die Chirurgie der Nebennieren. Vor-und Nachteile des anterioren und dorsalen Zugangs.

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.