Biomedical subjects
Publications and source records attributed to W Back.
A meningocele at the anterior fontanelle was diagnosed in a two-and-a-half month old Meuse-Rhine-Yssel calf. After radiographic and ultrasonographic evaluation, the meningocele was successfully repaired surgically.
The walking cast was used to repair 46 fractures of long bones (distal radius and tibia, metacarpus and metatarsus) and 10 fractures of first phalanx of 35 horses and 21 ponies. The walking cast proved to be highly effective. Even heavily comminuted and 'hopeless' fractures, which could not be treated with osteosynthesis, were treated successfully, because the weight of the animal, a common failure factor in large animal orthopaedics, was relieved from the injured leg. Immediate full weight bearing was possible post operatively. In five cases the walking cast was used in combination with osteosynthesis. Infection was the main complication that caused the walking cast to fail. Osteomyelitis may also be treated with a walking cast. Because of its success rate of 57 per cent, which is impressive, considering the type of fractures treated, we recommend the walking cast for international accreditation.
The significance of intrathyroidal lymphocytic infiltration is not known. However, several indirect lines of evidence suggest that interstitial or intraepithelial lymphocytes are the effector or thyroid autoantibody-producing lymphocytes in Graves' disease. This has not been investigated in vivo. Changes of nuclear volume of endocrine cells have previously been shown to be a reliable parameter of functional stimulation of endocrine glands. Therefore we investigated this parameter near and off lymphocytic aggregates, loosely distributed plasma cells and memory T cells in paraffin sections of Graves' disease thyroid glands. In 21 Graves' disease thyroid glands we found significant increases of thyroid epithelial cell nuclear volume near plasma cells (198.4 micron3) as well as near lymphocytic aggregates (219.1 micron3) compared with thyroid epithelial cell nuclear volume one microscopic field away (160.1 and 137.7 micron3 respectively). Similar nuclear volume differences were observed after propanolol and thiourelene antithyroid drug treatment. These nuclear volume differences could not be observed in 10 control thyroid glands and around CD45R0-positive memory T cells in Graves' disease thyroid glands. These direct in vivo investigations of regional functional stimulation of thyroid epithelial cells in Graves' disease show local stimulation near lymphocytic aggregates and diffusely distributed plasma cells. Therefore our in vivo data do not permit to identify stimulatory lymphocytes only interstitially or intraepithelially as previously suggested.
A 48-year-old woman complained of right-sided upper abdominal pain and recurrent vomiting, and had lost 10 kg in 4 months. Ultrasound and computed tomography showed a solid, space-occupying lesion in the head of the pancreas, not separable from the duodenum. Despite thorough investigation the nature of the lesion remained obscure. Operation revealed a divided pancreas with stenosis of the accessory duct at the papilla. Histological examination showed pseudosarcomatous myofibroblastic proliferation within the duodenal wall in the vicinity of a duodenal wall cyst which had been destroyed by inflammation. In cases of divided pancreas it is the accessory duct which drains the main bulk of the pancreas, while the main duct carries little or no secretion; the stenosis of the accessory duct in this patient had therefore led to low-grade pancreatitis involving the head of the pancreas.
A double antibody sandwich blocking ELISA, using a monoclonal antibody (MAb) against influenza A nucleoprotein (NP) was developed to detect antibodies against influenza. Collections of serum samples were obtained from human and various animal species. All influenza A subtypes induced antibodies against hemagglutinins and NP. A close correlation between titers of the hemagglutination inhibition (HI) test and the NP-ELISA was seen. Antibodies against influenza NP were demonstrated in serum samples from humans, ferrets, swine, horses, chickens, ducks, guinea pigs, mice, and seals. The serum samples were collected at intervals during prospective epidemiological studies, from experimental and natural infections, and vaccination studies. The decline of maternal antibodies was studied in swine and horses. The NP-ELISA enables rapid serological diagnosis and is suited for influenza A antibody screening, especially in species which harbor several influenza subtypes. The HI and neuraminidase inhibition tests, however, must still be used for subtyping.
More than 20 second-generation lithotriptors have been introduced for extracorporeal shock-wave lithotripsy. Despite great technical progress, each machine still has its specific short-comings. In cooperation, Storz Medical (Kreuzlingen, Switzerland) and the Department of Urology (Klinikum Mannheim, FRG), have developed a new lithotriptor designed to overcome these drawbacks. Energy source: Electromagnetic cylinder with paraboloid reflector (40 cm) for focusing, providing a wide range of pressure (190-1,000 bar) and a focal zone of 28 x 6 mm. The focal depth is maximally 15 cm. Coupling and positioning: Water cushion with patient lying on a specially designed 'acoustic cradle' consisting of an impedance-adapted foil. This is integrated in either a manually or automatically operated table. Localization: Coaxial ultrasound probe for real-time scanning and integrated C arm with pulsed fluoroscopy using a virtual focus (moved along x-axis) for stone localization. In 1989, we commenced with the first treatment based on our own in vitro and in vivo studies to determine the range of energy required for safe application. We treated 137 stones (100 caliceal, 19 pelvic and 18 ureteral) in 88 patients. The mean generator voltage was 16 kV (10-18 kV). Successful disintegration was achieved in 83 patients (95%) employing an average of 2,359 impulses (940-3,500). Thirteen percent of the treatments were performed without any anesthesia on lower generator voltage (10-15 kV), whereas the majority of calculi were treated under intravenous analgesia. The 5 failure cases included 2 stones in a caliceal diverticulum. Moreover, 12 patients with biliary calculi (11 gallstones and 1 bile duct stone) were successfully treated; 1 of these cases required a second treatment session.
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The effects of 5-hydroxykynuramine (5-OH-K) and of 3-(2-amino-5-hydroxyphenyl)-propaneamine (AHPP) on spontaneous and electrically evoked release of [3H]acetylcholine were studied in the guinea-pig myenteric plexus longitudinal muscle preparation preincubated with [3H]choline. 5-OH-K caused a concentration-dependent increase in spontaneous [3H]acetylcholine release (EC50 5.3 microM). This effect was diminished in the presence of a desensitizing concentration of 5-hydroxytryptamine (5-HT). AHPP (1-100 microM) did not affect the spontaneous outflow of [3H]acetylcholine. The electrically evoked release of [3H]acetylcholine was significantly reduced in the presence of 100 microM of either 5-OH-K or AHPP. Metitepine did not antagonize the inhibition, which suggests that 100 microM of either compound non-specifically depressed the evoked release. It is concluded that 5-OH-K is inactive at the release-inhibitory 5-HT1 receptor, but is a potent agonist at the M receptor of myenteric neurons.
In situ hybridization experiments were carried out with two clones, YACG 35 and 2.8, which had been selected from two genomic libraries strongly enriched for the human Y chromosome. Besides the human Y chromosome, both sequences strongly hybridized to the human X chromosome, with few minor binding sites on autosomes. In particular, on the X chromosome DNA from clone YACG 35 hybridized to the centromeric region and the distal part of the short arm (Xp2.2). On the Y chromosome, the sequence was assigned to one site situated in the border region between Yq1.1 and Yq1.2. DNA from clone 2.8 also hybridized to the centromeric region of the X and the distal part of the short arm (Xp2.2). On the Y, however, two binding sites were observed (Yp1.1 and Yq1.2). The findings indicate that sex chromosomal sequences may be localized in homologous regions (as suggested from meiotic pairing) but also at ectopic sites.
Intrinsic activity and affinity of various synthesized ring-opened serotonin (5-HT) analogues including 3-(2-amino-5-hydroxy-phenyl)-3-oxo-propaneamine (I) were studied using the isolated gastric fundus of the rat. For I a relative intrinsic activity of 0.83 was measured while the affinity was nearly equal to 5-HT. For the N,N-dimethyl derivative of I (V) both intrinsic activity and affinity were identical to those of bufotenine (= N,N-dimethyl serotonin). The obtained results support the postulated three-point binding of 5-HT at its D receptor.
The complete reduction of the carbonyl group of the 5-HT agonist 3-(2-amino-5-hydroxy-phenyl)-3-oxo-propanamine results in a drastic loss of activity: as investigations on the isolated gastric fundus of the rat showed, the affinity to the D receptor of serotonin is reduced by a factor of 100 whereas the relative intrinsic activity also decreases from 0.83 to values less than 0.3. The additional suppression of the phenolic hydroxyl group causes only a relatively unimportant decrease of the affinity while the relative intrinsic activity increases again up to 0.65. These results support the postulate according to which the active conformation of serotonin shows a stretched side chain, as its logical interpretation is only possible under this assumption. Inside the 1-(N-piperidino)-3-(2-amino-phenyl)-3-oxo-propanes the derivative methoxylated at C-5 of the benzene nucleus with a pA2 value of 7.39 proved to be the most effective 5-HT antagonist the mechanism being a purely competitive one.
Based on the earlier observation that DNP-HSA interacts directly with C1q, a subcomponent of the first component of complement (Loos and König, 1977), evidence is presented that TNP bound to erythrocytes (E-TNP) can interact with the whole complement sequence leading to the lysis of the TNP-carrying erythrocytes; in this test system the erythrocytes are used as an indicator of the TNP-complement reaction. To exclude any antibody-mediated lysis either the heterologus sera were exhaustively absorbed with the erythrocytes used in the test system or serum and erythrocytes of one individual person were taken. The strongly temperature-dependent interaction of TNP-sulfonic acid with the erythrocytes resulted in the formation of E-TNP as well as of a TNP-protein complex released into the supernatant. The TNP-protein complex strongly inhibited purified C1 similar to DNP-HSA. The antibody independent lysis of E-TNP by complement was dependent upon the TNP concentration per cell, the temperature and time as well as the complement concentration. The reaction of E-TNP with complement showed similar characteristics to those for the reaction of antibody sensitized erythrocytes (EA) with complement. E-TNP is a helpful tool to study antibody-independent activation of the complement system.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.