[Rotator cuff tear : Indications and pathology-specific reconstructive procedures]

Rotator cuff (RC) tears comprise a broad spectrum of lesions ranging from partial to full thickness tears of a single tendon and massive cuff tears. Both glenohumeral trauma as well as degenerative processes can result in tearing of the RC. Treatment therefore requires a meticulous diagnosis as well as a differentiated approach by careful consideration of morphological and patient-specific factors. The pathogenesis, tear morphology, clinical symptoms and functional demands of the patient determine the therapeutic approach. Despite pathological and individual patient-related factors, early surgical repair is generally recommended for traumatic RC tears in young patients and in patients with high functional demands due to the high risk of tear progression. The results of RC repair are negatively correlated with the size of the lesion, the number of tendons involved, the degree of tendon retraction, muscular alteration and patient age. This article provides an overview of the various pathogenesis, indications and surgical repair of RC tears with respect to modern pathology-specific reconstructive procedures.

Lysed Erythrocyte Membranes Promote Vascular Calcification

BACKGROUND

Intraplaque hemorrhage promotes atherosclerosis progression, and erythrocytes may contribute to this process. In this study we examined the effects of red blood cells on smooth muscle cell mineralization and vascular calcification and the possible mechanisms involved.

METHODS

Erythrocytes were isolated from human and murine whole blood. Intact and lysed erythrocytes and their membrane fraction or specific erythrocyte components were examined in vitro using diverse calcification assays, ex vivo by using the murine aortic ring calcification model, and in vivo after murine erythrocyte membrane injection into neointimal lesions of hypercholesterolemic apolipoprotein E-deficient mice. Vascular tissues (aortic valves, atherosclerotic carotid artery specimens, abdominal aortic aneurysms) were obtained from patients undergoing surgery.

RESULTS

The membrane fraction of lysed, but not intact human erythrocytes promoted mineralization of human arterial smooth muscle cells in culture, as shown by Alizarin red and van Kossa stain and increased alkaline phosphatase activity, and by increased expression of osteoblast-specific transcription factors (eg, runt-related transcription factor 2, osterix) and differentiation markers (eg, osteopontin, osteocalcin, and osterix). Erythrocyte membranes dose-dependently enhanced calcification in murine aortic rings, and extravasated CD235a-positive erythrocytes or Perl iron-positive signals colocalized with calcified areas or osteoblast-like cells in human vascular lesions. Mechanistically, the osteoinductive activity of lysed erythrocytes was localized to their membrane fraction, did not involve membrane lipids, heme, or iron, and was enhanced after removal of the nitric oxide (NO) scavenger hemoglobin. Lysed erythrocyte membranes enhanced calcification to a similar extent as the NO donor diethylenetriamine-NO, and their osteoinductive effects could be further augmented by arginase-1 inhibition (indirectly increasing NO bioavailability). However, the osteoinductive effects of erythrocyte membranes were reduced in human arterial smooth muscle cells treated with the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide or following inhibition of NO synthase or the NO receptor soluble guanylate cyclase. Erythrocytes isolated from endothelial NO synthase-deficient mice exhibited a reduced potency to promote calcification in the aortic ring assay and after injection into murine vascular lesions.

CONCLUSIONS

Our findings in cells, genetically modified mice, and human vascular specimens suggest that intraplaque hemorrhage with erythrocyte extravasation and lysis promotes osteoblastic differentiation of smooth muscle cells and vascular lesion calcification, and also support a role for erythrocyte-derived NO.

Measurements of the neutron spectrum in transit to Mars on the Mars Science Laboratory

The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011. Although designed for measuring the radiation on the surface of Mars, the Radiation Assessment Detector (RAD) measured the radiation environment inside the spacecraft during most of the 253-day, 560-million-kilometer cruise to Mars. An important factor for determining the biological impact of the radiation environment inside the spacecraft is the specific contribution of neutrons with their high biological effectiveness. We apply an inversion method (based on a maximum-likelihood estimation) to calculate the neutron and gamma spectra from the RAD neutral particle measurements. The measured neutron spectrum (12-436 MeV) translates into a radiation dose rate of 3.8±1.2 μGy/day and a dose equivalent of 19±5 μSv/day. Extrapolating the measured spectrum (0.1-1000 MeV), we find that the total neutron-induced dose rate is 6±2 μGy/day and the dose equivalent rate is 30±10 μSv/day. For a 360 day round-trip from Earth to Mars with comparable shielding, this translates into a neutron induced dose equivalent of about 11±4 mSv.

Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory

The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011, and for most of the 253-day, 560-million-kilometer cruise to Mars, the Radiation Assessment Detector made detailed measurements of the energetic particle radiation environment inside the spacecraft. These data provide insights into the radiation hazards that would be associated with a human mission to Mars. We report measurements of the radiation dose, dose equivalent, and linear energy transfer spectra. The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert.

[Visualized medicine. Macroscopy, molecular anatomy and medical art]

Quite frequently clinicians avail themselves of works of well known artists in order to illustrate certain diseases. In contrast, pathologists find it harder to use art to demonstrate morphology. My approach to compensate for this is twofold: on the one hand, with 8 mostly three dimensional wooden objects with either mirror or aluminium elements, on the other with 449 collages consisting of pictures exclusively with a medical background (histology, radiology, nuclear medicine) or showing a combination of histological or cytological photos with pictures of flowers, trees or landscapes. My experience is that this technique arouses interest in complex medical issues even with medically unqualified individuals.

The CD63 basophil activation test in Hymenoptera venom allergy: a prospective study

BACKGROUND

The basophil activation test (BAT), which relies on flow cytometric quantitation of the allergen-induced up-regulation of the granule-associated marker CD63 in peripheral blood basophils, has been suggested to be a useful approach in detecting responsiveness to allergens. The purpose of this study was to establish the usefulness of the BAT with regard to the clinical history and current diagnostic tools in Hymenoptera venom allergy using a prospective study design.

METHODS

Fifty-seven consecutive patients allergic to Hymenoptera venom as defined by a systemic reaction after an insect sting, and 30 age- and sex-matched control subjects with a negative history were included. The degree and nature of sensitization was confirmed by skin testing, specific immunoglobulin E (IgE), serum tryptase levels and BAT. In the nonallergic control group only analysis of specific IgE and BAT were performed. Correlation of BAT, skin test and specific IgE, respectively, with the clinical history in the allergic group was termed as sensitivity and in the control group as specificity.

RESULTS

Twenty one of 23 (91.3%) bee venom allergic patients and 29 of 34 (85.3%) patients allergic to wasp and hornet venom tested positive in BAT. The overall sensitivity of BAT, specific IgE and skin tests were 87.7, 91.2 and 93.0%, respectively. The overall specificities were 86.7% for BAT and 66.7% for specific IgE. No correlation between the severity of clinical symptoms and the magnitude of basophil activation was observed.

CONCLUSION

The BAT seems to be an appropriate method to identify patients allergic to bee or wasp venom with a comparable sensitivity to standard diagnostic regimens. The higher specificity of BAT as compared with specific IgE makes this test a useful tool in the diagnosis of Hymenoptera venom allergy.

Therapeutic use of the natriuretic peptide ularitide in acute renal failure

BACKGROUND

Ularitide is a member of the natriuretic peptide family. This hormone exhibits an N-terminal extension by four amino acids compared with atrial natriuretic peptide. Ularitide was shown to exert strong diuretic and natriuretic effects when infused intravenously. Its main action sites are the glomerulum, inducing preglomerular vasodilation and postglomerular vasoconstriction and thereby elevating the glomerular filtration rate, and the tubular system inhibiting Na(+)-reabsorption. In initial uncontrolled clinical trials, this peptide was shown to have beneficial effects in patients suffering from oliguric acute renal failure.

METHODS

We conducted a double-blind, placebo-controlled, multicenter, dose-finding trial recruiting 176 patients randomized into 4 different Ularitide doses groups (U5, U20, U40, and U80 ng/kg/min) and a placebo group (U0). Ularitide/placebo infusion was performed for 5 days with half the originally infused dose on day 5. The primary objective of the study was to test various doses of Ularitide in patients suffering from oliguric acute renal failure to avoid mechanical renal replacement therapy during the first 12 hours.

FINDINGS

The results indicate that Ularitide does not reduce the incidence of mechanical renal replacement therapy compared with placebo-treated patients during the first 12 h of treatment (U0: 36 (20), U5: 35 (11), U20: 36 (9), U40: 28 (8), U80: 41 (12), (% (n) (p = 0.87)). Diuresis increased in the Ularitide-treated groups and the placebo group after onset of infusion and did not show any significant difference in the first 12 h collection period (U0: 576, U5: 514, U20: 500, U40: 360, U80: 158 ML/12h (Median), (p = 0.16)).

INTERPRETATION

In summary, the incidence of mechanical renal replacement therapy in critically ill patients suffering from oliguric acute renal failure could not be altered positively by Ularitide administration according to our protocol. Further prospective clinical trials are needed to answer the question whether a different patient collective or a prophylactic administration of Ularitide are more promising approaches in the clinical setting of oliguric acute renal failure.

[Alveolar hemorrhagic syndrome in sarcoidosis]

BACKGROUND

Alveolar hemorrhage is uncommon in sarcoidosis, even in the presence of severe alveolitis.

PATIENT

A heavy smoker with bihilar adenopathy presented with severe alveolar hemorrhage in the absence of radiological signs of pulmonary involvement. Sarcoidosis was confirmed histologically by transbronchial and mediastinal lymph node biopsies. The bleeding stopped before the installation of anti-inflammatory medication and did not reoccur within 9 months of follow up, but BAL analysis demonstrated the persistence of alveolar siderophages.

CONCLUSIONS

Sarcoidosis should be considered as a rare cause of diffuse alveolar hemorrhage.

[Differentiated metastasis of mature testicular teratoma as differential kidney and adrenal tumor diagnosis]

We report on the eighth known case of a mature metastasis of a mature teratoma of the testis. In a 19-year-old patient who had undergone a pyeloplasty of the left renal pelvis 6 years before, a mature metastasis of an occult mature teratoma of the testis was found at the former operation site. This case--in addition to those published previously--emphasizes the fact that a mature teratoma of the testis has to be regarded as a malignant tumor in adults. It is supposed that the mature teratoma originates, as other testicular tumors, from carcinoma-in-situ-cells, which are responsible for metastasize and are not detected after lysis.

Ularitide: from renal natriuretic peptide to clinical trials

Ularitide is a member of the natriuretic peptide family which is presumably synthesized in the kidney. In physiological experiments a correlation between Ularitide excretion and natriuresis has been found. Ularitide infusions and bolus injections in animals initiated profound diuresis and natriuresis as the most prominent effects. On the basis of findings in in-vitro and in-vivo experiments, Ularitide was used in clinical trials, and the results indicate that it could be a promising new drug to prevent and treat acute renal failure in patients after cardiac surgery and organ transplantation.

The impact of disease pattern, surgical management, and individual surgeons on the risk for relaparotomy for recurrent Crohn's disease

OBJECTIVE

The authors provide a multivariate analysis of a large single-center experience with limited surgery for Crohn's disease.

SUMMARY BACKGROUND DATA

During the past decade, the aim of surgery for Crohn's disease has shifted from radical operation, achieving inflammation-free margins of resection, to "minimal surgery," intended to remove just grossly inflamed tissue or performing strictureplasties.

METHODS

Seven hundred ninety-three cases of resection and/or strictureplasty in 689 individuals with histologically verified Crohn's disease were followed for a mean period of 50 months (range, 5-166 months). Two different end points were analyzed: 1) any relaparotomy for recurrent (or persistent) Crohn's disease and 2) relaparotomy for site-specific recurrence. More than 30 variables of patient/disease characteristics and surgical management were included in a proportional hazard model.

RESULTS

Five parameters were associated independently with the risk for relaparotomy: increased risk coincided with young age at onset of disease, involvement of jejunum, enterocutaneous fistula, or performed strictureplasty, and decreased risk followed ileocecal resection. Site-specific risks of reoperation were calculated on the basis of 1260 intestinal resections or anastomoses performed in these patients. Young age at onset, duodenal and jejunal involvement, presence of enterocutaneous or perianal fistula, and a single surgeon (of 23) were associated significantly with increased risk of regional recurrence but not strictureplasty or inflammation at margins of resection.

CONCLUSIONS

Limited surgery for Crohn's disease is not associated with increased risk of regional recurrence requiring reoperation. However, patients with juvenile onset, proximal small bowel disease, and some types of fistulae are at a considerable risk of experiencing early surgical recurrence.

[A combination of spermatocytic and classic seminoma, mature teratoma and carcinoma in situ of the testis. An attempt at an etiologic explanation]

We report of a 39 years old patient with a large testicular tumor found during an examination for infertility. The tumor consisted of a spermatocytic seminoma (SS) and a differentiated teratoma (TD). Furthermore, two small foci of seminoma were seen in the surrounding testicular tissue, several testicular tubuli contained carcinoma in situ (CIS). The diagnosis was based on the results obtained with various immunohistochemical markers: keratin, vimentin, desmin, LCA, CD3, CD20, CD45R, ferritin, PLAP, AFP. On the basis of the macroscopic and histopathological features, we propose the following etiology: CIS progressed in an earlier phase to the (larger) TD and later to the (smaller) classical seminoma; likewise, in an earlier phase, SS developed from a still unknown precursor stage. Our case of a mixed tumor as well as other cases reported in the last years do not allow the explanation of a differing etiology for SS. On the contrary, it may be presumed that the origins of seminoma and teratoma on the one hand and SS on the other hand are less divergent than hitherto thought.

What's new in exogenous osteomyelitis?

By the increase in road and occupational accidents during the past few decades posttraumatic osteomyelitis has become not only the most important type of exogenous but of all inflammatory bone processes. The major morphologic, bacteriologic and immunologic studies about posttraumatic bone inflammation will be outlined in this survey. The histologic classification of chronic osteomyelitis has proved useful for the observation of the course and for the selection of the treatment in 1,500 patients. Detailed morphological studies have shown that posttraumatic osteomyelitis often begins with a necrosis of the outer tangential lamella of the tubular bone partly promoted by partial periosteal retrogression, possibly followed by a necrosis of the fracture ends caused by a disturbance of the medullary blood circulation. Type and extent of osteomyelitis are determined by several traumatic, therapeutic and endogenous factors. Bacteriologically an infection with staphylococcus aureus is still prevailing. Comparative studies about the causative agents shortly after the trauma and during the following osteomyelitis have basically shown an identical range of causative agents. Immunologic studies with monoclonal antibodies in the actual site of inflammation have on the one hand found a decrease in the number of T-lymphocytes and the T-helper cells and on the other hand an increase in the T-suppressor cells, natural killer cells, macrophages in the osteomyelitic site. The impact of these findings on the therapy of osteomyelitis can presently not be estimated. However, they will become important after immunohistochemical studies of the bone and soft tissue Lager in osteosynthetic material after aseptic bone surgery have been carried out.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological characteristics of the stereoisomers of carvedilol

The racemic compound carvedilol possesses two complementary pharmacological effects, vasodilation and beta-blockade. The R- and S-enantiomers of carvedilol and the racemate were investigated with respect to the beta-blocking, vasodilating, and hypotensive actions. In agreement with results obtained with other beta-blockers, only the S-enantiomer of carvedilol exerts beta-blocking effects. In contrast, no substantial difference between the enantiomers could be seen with respect to alpha-blockade. The greater hypotensive activity of S-carvedilol may be attributed to beta-blockade, which inhibits counter-regulatory mechanisms provoked by vasodilation. From these results it is concluded that there is a rationale for using carvedilol as the racemate. Using the S-enantiomer would lead to relatively strong beta-blockade with only a weak vasodilating effect. The R-enantiomer alone would act only as a hypotensive agent without beta-blockade.

[Achilles tendon rupture. Anamnestic and morphologic studies and considerations on the etiology]

From 1. October 1985 to 31. December 1987 93 patients (82 male, 11 female) with rupture of the achillestendon were investigated by means of a questionnaire, the specimens obtained at operation were examined histologically. In two cases the operation was for a rerupture of the tendon, 7 and 8 weeks respectively after the first operation. In 6 cases a rupture followed a so-called incomplete rupture on the same side. 9 patients had had a tendonrupture of the other side between 2.5 and 10 years previously. 85.4% of the ruptures took place during a sporting activity. Of the 93 patients 55 (59%) regularly took part in long term sporting activities. Symptoms in the area of one or both achilles tendons were experienced by 32% of the patients. 80 patients with an achilles tendon rupture who were operated within 10 days demonstrated structural degeneration of at least moderate proportions, mostly severe or very severe (there was no relationship between the degree of degeneration and the age of the rupture). The signs of repair were consistent with the age of the rupture. In 56% of the ruptures up to four days old the repair process was considerably more advanced than the age of the rupture would suggest. 6 of 10 patients with the so-called "Archillodynie" demonstrated minor changes although 3 had more severe degenerative changes. Our inquiry clearly demonstrates that structural changes in the tendon took place before the injury. In the cases of achilles tendon rupture the processes of repair are an-adequate to compensate for the degenerative changes. The etiology of the structural degenerations is dependent on many endogenous and exogenous factors particularly the inadequacy of the repair processes.

[Decubitus ulcer in paraplegic patients--a comparative clinico-pathologic study]

331 pressure sores of 141 patients with paraplegia were investigated histologically, the results were partly correlated with the roentgenological features. The level of the spinal cord lesion was the segment Th12-L1 in 45%, the decubital ulcers were mostly localized above the os ischiadicum (64%). A pseudocancerosis was diagnosed in 14.2%, one time a cancer in a sacral decubitus has been found. The inflammation was limited to the soft tissue in 56.9%, in 28.5% a chronic osteomyelitis of different severity had developed. In 73.6% of the patients with a histologically proven osteomyelitis this osteomyelitis could be diagnosed roentgenologically too. The high amount and severity of the dermal and bony lesions justifies the radical surgical therapy of the pressure sores, which is practised today. Our investigations of chronic pressure sores did not point out new aspects of aetiology of pathogenesis--this is only possible by experimental models.

[Idiopathic femur head necrosis in the adult--relation to clinical and pathologic-anatomic findings]

For the research here presented, a total of 15 femoral heads with idiopathic necrosis in 15 patients, ranging in the age from 28 to 59 years, were available. In 7 of the histologically examined, in the occasion of endoprosthetic obtained femoral heads, a singular necrosis was to be discovered. In 6 items two attacks of necrosis, in 2 even three attacks could be confined. The comparison of these results with the clinically obtained case history showed that the second as well as the third attack of necrosis occurred during the first two years of the disease and partly obvious due to the increase of subjective symptoms. With the knowledge of these facts, it may be assumed that by means of exact observation of the patients concerned, even after diagnosis has been made, valuable tips to solve the up to now still unknown etiology of idiopathic avascular necrosis could be won.

[Multiple lipomas of the colon. Case report with clinical, roentgenologic, angiographic and histologic findings]

Case report on a 26 year old woman with multiple lipomas of the colon and rectum and a neurofibromatosis simultaneously. Description and discussion of clinical data and differential diagnosis. The vascularisation of the lipomas and of the overlying mucosa was proved to be good angiographically. This is the reason for the frequent bleeding of the lipomas of the colon. The coincidence of multiple lipomas and neurofibromatosis is rare. Therefore conclusions for a possible common etiology of the two diseases should be drawn only after further reports.

Pharmacokinetics of the thioether phospholipid analogue BM 41.440 in rats

BM 41.440 (1-hexadecylmercapto-2-methoxymethyl-rac-glycero-3-phosphocholine) is a cytotoxic thioether phospholipid analogue that recently has entered phase I trials in cancer patients. The objective of this study was to evaluate the pharmacokinetics of this compound in female rats after administration of a single oral dose (15 mg/kg body weight [bw] ). Furthermore, BM 41.440 serum concentrations were determined under a daily oral treatment of up to 13 weeks. Blood samples were obtained via permanent catheters from the femoral arteries before and after drug administration for a total of 120 hr. Urine was collected in 24 hr-intervals for 120 hr; the volume was measured, and aliquots were stored at -20 C until analytical determination of the thioether derivative. BM 41.440 was assayed in serum and urine by means of a specific, newly developed reverse-phase high pressure liquid chromatography technique. Mean maximum serum concentrations (1.7 micrograms/ml, n = 4 animals) were attained after seven hr. A terminal half-life of ca. 27 hr was calculated from the rate constant for the terminal elimination phase (lambda z approximately 0.026/hr). The mean serum BM 41.440 concentration-time-area-under-the-curve was 52.9 mg X hr/l. The ratio of total body clearance to absorption fraction was 4.7 ml/min X kg bw. Only a small amount of the drug was found in the urine. The quantity excreted in the urine during a 24 hr-interval never exceeded 1.5% of the administered dose.(ABSTRACT TRUNCATED AT 250 WORDS)

[Changes in lung function following administration of eyedrops containing timolol, metipranolol, pindolol and pilocarpine in healthy probands and patients with mild bronchial asthma]

Lung function was studied double blind and randomized in 5 patients with mild asthma bronchiale and 10 normal adults before and 30, 60 and 90 minutes after one drop of 0.5% Timolol, 0.6% Metipranolol or 0.9% NaCl in each eye. In the asthmatics bronchoconstriction was seen after both beta-receptor blocking agents, more pronounced after Timolol than after Metipranolol. There was a decrease in the forced expiratory volume in one second (FEV1.0) of 32, respectively 18%. No changes were observed in the normal subjects. In a separate study no significant changes were seen in the mean values of 10 other asthmatic subjects after 1% Pindolol, 3% Pilocarpin or 0.9% NaCl. However, in two patients FEV1.0 was reduced by 15% and 20% of the control values after applying Pindolol. In summary, not only beta-receptor-blocking agents without ISA produce a bronchoconstriction in asthmatic subjects, but also beta-blocker with ISA in individual cases.

[Ultrastructural differences of fibrin coagulation before and after cardiovascular arrest]

The reconstruction of killing offences often requires the differentiation between vital and postmortal blood traces at the sites of action and finding. Earlier investigations seemed to imply the possibility of such a differentiation depending on the different clot structure. We therefore examined clots prior and after 10 minutes of complete occlusion of the upper extremity morphologically and morphometrically with the REM. The morphologic comparison of these clots revealed narrow, round shaped fibrin fiber networks for clots of native blood, whereas clots after occlusion showed linear, rarely connected long fibrin fibers. The morphometry of the fibrin free spaces revealed a significant enlargement of the single fibrin free spaces as well as of the total fibrin free space after occlusion. For capillary blood a significant decrease in fiber diameter was observed after occlusion. The examination of clinical clotting parameters revealed alterations of thrombocyte aggregation for the collagen induction, a slightly reduced thrombocyte retention and slightly steeper flanks in the thromboelastogram after occlusion. The reason for these changes was interpreted as lack of high energetic phosphates in the retraction process as the clotting cascade itself requires a very high amount of these phosphates. Use of these results in the forensic practice will have to take factors as temperature, drying out, surface-structure and many others into account.

Pharmacological profile of carvedilol as a beta-blocking agent with vasodilating and hypotensive properties

Carvedilol is a new beta-receptor blocking and vasodilating drug that is presently undergoing clinical trials in hypertension and coronary heart disease. In this article, the pharmacodynamic properties of carvedilol are compared with those of standard drugs. The beta-blocking activity was characterized in isolated organs and in conscious rats, rabbits, and dogs. For the beta 1-blockade in guinea pig atria, the pA10 values were 7.44 +/- 0.16 for carvedilol and 6.77 +/- 0.08 for propranolol. Carvedilol is a noncardioselective beta-blocker. The i.v. doses that inhibited the tachycardia by 50% induced by 1 microgram/kg isoprenaline were 62 micrograms/kg in dogs, 138 micrograms/kg in rabbits and 841 micrograms/kg in rats. In rabbits carvedilol was slightly more active and in rats less active than propranolol. In all models, carvedilol was much more active than labetalol or prizidilol. In contrast to propranolol, carvedilol relaxed rat aortic strips. A dose-dependent decrease in arterial blood pressure was seen in different in vivo models. The total peripheral and coronary resistance were decreased in conscious dogs. The doses required for both beta-blockade and decrease in blood pressure were in the same range. The drug was also active after oral administration. There is no hint for development of tolerance.

[Structural principles of hemostatic processes]

The formation of the hemostatic plug on areas of skin injury is characterized as a sequence of structure-forming processes ending in the formation of an impenetrable barrier. The morphology of this barrier is further elucidated by means of scanning- and transmission electron microscopy. Especially the fibrin coating of the injury shows a completely different formation than is deducible from the solely hemostaseologically orientated view of the formation of the hemostatic plug. These structure-forming processes are: activation of the intrinsic clotting system by means of explosion-like destruction of thrombocytes with an immediate formation of a fibrin clot within seconds after the injury. Later during the process the fibrin clot is then condensed and as a function of thrombocyte dependent retraction receives its final fibrin stabilisation and modellation towards an occluding plug. The very narrow net formation of fibrin fibers is interpreted as dependent on the destruction of thrombocyte pseudopodia using their round shape as a rail for fibrin fiber formation. Disturbances of clot formation of postmortal clots compared to vital clots are interpreted as functional thrombocytic distortions, especially of the thrombocytic energy metabolism. Extracorporal clotting of blood drops after extreme ischemia resemble fibrin structures and fibrin structure formation distortions of postmortal origin.

The role of cytoplasmic (newly synthesized) dopamine for the spontaneous and electrically evoked release of dopamine and its metabolites from the isolated neurointermediate lobe of the rat pituitary gland in vitro

Isolated rat NILs were incubated in Krebs-HEPES solution. The release of dopamine and its metabolites (DOPAC, HVA and MOPET) was determined by HPLC with electrochemical detection. The spontaneous release of the sum of metabolites was about 40 times that of dopamine. The spontaneous outflow of dopamine metabolites was unaffected after inhibition of dopamine uptake (by GBR 12921) or after pretreatment with reserpine (5 mg/kg, 12 h before the experiments), but it was reduced by 50% after preincubation with the irreversible DOPA decarboxylase inhibitor, (MFMD, 10 microM, for 10 min). The combination of pretreatment with reserpine and preincubation with MFMD resulted in an 80% inhibition of the spontaneous outflow of dopamine metabolites. Treatment with reserpine caused a 98% depletion of the dopamine tissue content, whereas 60 min after exposure to MFMD the dopamine tissue content was decreased by 40%. Electrical stimulation of the pituitary stalk (3-15 Hz, in the presence of GBR 12921) caused a frequency-dependent release of dopamine. Stimulation at 7 or 15 Hz caused also a significant release of dopamine metabolites. After pretreatment with reserpine, the release of dopamine evoked by stimulation at 15 Hz was abolished, whereas the evoked release of the metabolites was only reduced by about 55%. After MFMD, the evoked release of dopamine decreased by a percentage similar to that of dopamine tissue content, but the reduction of the evoked release of metabolites was more pronounced. In conclusion, the spontaneous release of dopamine metabolites from the dopaminergic nerve endings in the NIL largely reflects the catabolism of newly synthesized dopamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Endogenous opioids inhibit the in vitro release of endogenous dopamine preferentially in the neural lobe of the rat neurointermediate lobe

The release of endogenous dopamine (DA) from the in vitro incubated combined neurointermediate lobe (NIL) or isolated neural lobe (NL) was studied. In the presence of the DA uptake inhibitor GBR 12921 (200 nM), electrical stimulation of the pituitary stalk caused an increase of the outflow of DA from the NIL in a frequency-dependent manner. Naloxone (1 microM) enhanced the DA release from the NIL evoked by electrical stimulation at 7 or 15 Hz by about 40%, but had no effect on DA release evoked by stimulation at 3 Hz. When the electrical stimulation was carried out at 15 Hz, the evoked DA release (expressed as fraction of the DA tissue content) from the NL amounted to only 15% of that from the combined NIL. Naloxone (1 microM) increased the evoked DA release from the isolated NL by 242%. Thus, the effect of naloxone on DA release from the combined NIL may be confined mainly to the NL. In conclusion, DA release from the NL is under inhibitory control of endogenous opioids released from the NL during stimulation at 7 or 15 Hz. Beta-Endorphin, known to be released spontaneously at a high rate from in vitro incubated NILs, appears to lack inhibitory effects on DA release from the NIL.

[Studies on the angioarchitecture of polypoid colonic processes]

Portions of the colon removed at operation were studied angiographically after arterial or venous injection with a barium-gelatin mixture. The aims of the investigation were: To study the differences between tumour and inflammatory angiographic appearances and the clinical value of in vivo angiography of the mesenteric arteries. A comparison of the micro-angiographic appearances of benign and malignant polypoid lesions of the colon. Adenomas and carcinomas showed patterns which are easy to distinguish and permit classification in uncertain lesions. Pseudopolyps in Crohn's disease resemble adenomas in the early stages, but later assume features characteristic of tumours.

Hydroxyl radical-induced strand break formation of poly(U) in the presence of oxygen: comparison of the rates as determined by conductivity, e.s.r. and rapid-mix experiments with a thiol

The rate of OH radical-induced strand break formation of single-stranded poly(U) in N2O/O2-saturated aqueous solution was studied by measuring the time-dependence of the electrical conductivity following pulse radiolysis. The first half-life of the total conductivity increase depends slightly on pH and the molecular weight and on the dose per pulse. The activation parameters for strand break formation were found to be EA = 52 kJ mol-1 and A = 5 X 10(8) s-1. Similar first half-lives were observed when the decay of peroxyl radicals of poly(U) was measured by e.s.r. under various conditions. This indicates that poly(U)-peroxyl radicals are involved in the rate-determining step of strand break formation. After pulse radiolysis, strand break formation can be inhibited by the addition of dithiothreitol (DTT) in a rapid-mix apparatus. It is postulated that peroxyl radicals of poly(U) react with DTT by formation of hydroperoxides, thereby preventing strand breakage.

Comparison of the haemodynamic profiles of the hypotensive action of verapamil and carvedilol

Comparative haemodynamic investigations with carvedilol and verapamil were carried out on conscious, instrumented dogs. Arterial blood pressure, right atrial pressure (RAP), cardiac output (CO), heart rate, stroke volume and total peripheral resistance (TPR) were determined after intravenous (i.v.) injection of incremental doses (0.01-3 mg/kg) of the drugs. Carvedilol reduced the blood pressure in a dose-dependent manner, concomitant with a reduction in TPR. The RAP and the CO were not affected, indicating that arterial vasodilatation was induced by carvedilol. Verapamil showed a decrease in the blood pressure with a reduction of CO and SV. Moreover, at high doses the RAP was increased, indicating a reduction of the cardiac performance. Thus, in our experimental model remarkable differences between the haemodynamic effects of i.v. injections of carvedilol and verapamil have been observed, whereas after oral administration blood pressure also decreases after verapamil due to a reduction of TPR.

Gastric perforation secondary to metastatic bronchogenic carcinoma

A case of gastric perforation due to a gastric metastasis of a primary bronchogenic carcinoma is presented. While ten cases of small intestinal perforation secondary to bronchogenic tumor spread were identified in the literature, there appears to be only one further report on a gastric perforation caused by bronchogenic carcinoma.

[Arteriographic features of rare skin complications of chronic osteomyelitis]

In the period between 1970 and 1982, 6 carcinomas in scar tissue and 2 pseudocarcinomatous skin papillomatosis were found on the basis of chronic osteomyelitides. Amputation specimens of two carcinomas and one papillomatosis were examined by arteriography. Macroscopically carcinomas in scar tissue showed an unspecific appearance and microscopically a scarefied and partly pathological vascular appearance. Pseudocarcinomatous skin papillomatosis was distinctly hypervascular. Therefore, indications with regard to the localisation of an required exploratory excision can only be obtained from the vascular appearance of papillomatosis but not in case of a scar tissue carcinoma after osteomyelitis. Due to the overall bad blood circulation osteomyelitic scar tissue carcinoma scarcely reacts positively to a chemotherapeutic treatment.