Biomedical subjects
M Blank
Publications and source records attributed to M Blank.
Intramural distribution of immunoreactive vasoactive intestinal polypeptide (VIP), substance P, somatostatin and mammalian bombesin in the oesophago-gastro-pyloric region of the human gut.
The intramural distribution of vasoactive intestinal polypeptide (VIP), substance P, somatostatin and mammalian bombesin was studied in the oesophago-gastro-pyloric region of the human gut. At each of 21 sampling sites encompassing this entire area, the gut wall was separated into mucosa, submucosa and muscularis externa, and extracted for radioimmunoassay. VIP levels in the mucosa were very high in the proximal oesophagus (1231 +/- 174 pmol/g, mean +/- SEM) and showed varied, but generally decreasing concentrations towards the stomach, followed by a clear-cut increase across the pyloric canal (distal antrum: 73 +/- 16 pmol/g, proximal duodenum: 366 +/- 62 pmol/g); consistent levels were found in submucosa and muscle (200-400 pmol/g) at most sites, the stomach again showing lower concentrations. By contrast, substance P was present in small amounts as far as the proximal stomach, but sharply increased across the pyloric canal, especially in mucosa and submucosa (distal antrum: 20 +/- 6.5 and 5.5 +/- 1.3 pmol/g; proximal duodenum: 62 +/- 8.5 and 34 +/- 11 pmol/g, respectively). Somatostatin concentrations were very low in the mucosa of the oesophagus and stepwise increased in the cardiac, mid-gastric and pyloric mucosa (cardia: 224 +/- 72 pmol/g; distal antrum: 513 +/- 152 pmol/g; proximal duodenum: 1013 +/- 113 pmol/g); concentrations in the submucosa and muscularis were generally low, with the exception of antrum and duodenum. Mammalian bombesin was comparatively well represented throughout the oesophageal muscularis (5-8 pmol/g), but most abundant in the stomach in all layers (oxyntic mucosa: 24 +/- 2.7 pmol/g; submucosa: 20 +/- 5.7 pmol/g; muscle: 28 +/- 5.0 pmol/g).(ABSTRACT TRUNCATED AT 250 WORDS)
The role of the human anti-DNA idiotype 16/6 in autoimmunity.
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Binding of monoclonal anti-DNA and anti-TB glycolipids to brain tissue.
The binding of human lupus anti-DNA antibodies and murine anti-mycobacterial antibodies to human cortical brain tissue sections was assessed by the indirect immunofluorescent technique. Prior adsorption of the reactive monoclonal antibodies on nuclear extracts, ss-DNA, synthetic polynucleotide polymers, histones, mycobacterial glycolipids, and bovine brain extracts abrogated the monoclonal antibodies' binding to the brain. Intermediate blocking activity was conferred also by ribonucleic components as RNP, Ro(SSA), and La(SSB). Specificity to neuronal tissue was demonstrated by failure of non-neuronal tissue extracts to abolish antibodies' reaction to the cortical tissue sections in competition assays. The anti-TB and anti-DNA antibodies seemed to compete on their binding to a common neuronal membranal epitope. These results indicate that mycobacteria share antigens with DNA and human brain tissue. Furthermore, these data support the concept that anti-DNA antibodies may play a pathogenetic role in SLE patients with neuropsychiatric involvement via crossing of a "leaky" blood brain barrier and attachment to brain tissue components.
MHC fully allogeneic bone transplantation after physical T-cell depletion with magnetic microspheres (MAMIS).
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[Exchange of the hematopoietic system changes chemosensory identity].
It has been shown that the scent of mice changes after a bone marrow transplantation. Previously obtained results were re-examined with a new design that rules out possible avoidance learning effects. Two BALB/c mice, deprived of water for 20 hours each day, were trained in a Y-maze to discriminate two fully allogeneic mice strains (C3H = S+ and C57 = S-) via their urine odor. Reinforcement for correct choice was provided by a drop of water. Urine samples of different fully allogeneic mice strains (C3H, C57 and A/J) and bone marrow transplanted chimeras (C57----C3H and C3H----C57) were submitted to different "transfer of training" -tests. In the conditioning paradigm used, the animals learn to identify S+ and also do not avoid S- after the training. The urine odor of the C57----C3H-chimeras was found to be different from the strain-specific urine odor of C3H animals. Since this change could not be found in syngeneic transplanted chimeras, it is concluded that it is caused by the graft. The experiments failed, however to demonstrate that the urine odor of allogeneic chimeras is constituted solely by donor- and recipient-specific components.
A human monoclonal anti-DNA antibody derived from a patient with polymyositis having the common lupus 16/6 idiotype.
A human IgM monoclonal antibody (Pol-1, SA-1) was generated by the human hybridoma technique from the peripheral blood lymphocytes (PBL) of a patient with active polymyositis. The antibody was found to bind to ssDNA, dsDNA, poly(I) and poly(G) and to carry the common lupus anti-DNA antibody idiotype (16/6 Id). Another human IgM monoclonal antibody (Pol-2, SA-2) produced by similar methods from the PBL of the same patient while in remission lacked the ligand-binding capacities of Pol-1 SA-1 and did not have the 16/6 Id. Analyses of 19 sera samples from patients with polymyositis showed no antinuclear antibodies, excluding a 40% prevalence of the 16/6 Id. The serum of the patient whose lymphocytes were employed to generate the hybridoma was negative for anti-DNA activity as well as for the 16/6 Id. This study suggests that the hybridoma technique may enable expression of dormant idiotypic affinities which do not normally appear in sera.
Carcinogen-induced trans activation of gene expression.
We report a new mechanism of carcinogen action by which the expression of several genes was concomitantly enhanced. This mechanism involved the altered activity of cellular factors which modulate the expression of genes under their control. The increased expression was regulated at least in part on the transcriptional level and did not require amplification of the overexpressed genes. This phenomenon was transient; it was apparent as early as 24 h after carcinogen treatment and declined a few days later.
Intramural distribution of regulatory peptides in the sigmoid-recto-anal region of the human gut.
The distribution of regulatory peptides was studied in the separated mucosa, submucosa and muscularis externa taken at 10 sampling sites encompassing the whole human sigmoid colon (five sites), rectum (two sites), and anal canal (three sites). Consistently high concentrations of VIP were measured in the muscle layer at most sites (proximal sigmoid: 286 (16) pmol/g, upper rectum: 269 (17), a moderate decrease being found in the distal smooth sphincter (151 (30) pmol/g). Values are expressed as mean (SE). Conversely, substance P concentrations showed an obvious decline in the recto-anal muscle (mid sigmoid: 19 (2.0) pmol/g, distal rectum: 7.1 (1.3), upper anal canal: 1.6 (0.6)). Somatostatin was mainly present in the sigmoid mucosa and submucosa (37 (9.3) and 15 (3.5) pmol/g, respectively) and showed low, but consistent concentrations in the muscle (mid sigmoid: 2.2 (0.7) pmol/g, upper anal canal: 1.5 (0.8]. Starting in the distal sigmoid colon, a distinct peak of tissue NPY was revealed, which was most striking in the muscle (of mid sigmoid: 16 (3.9) pmol/g, upper rectum: 47 (7.8), anal sphincter: 58 (14)). Peptide YY was confined to the mucosa and showed an earlier peak (upper sigmoid: 709 (186) pmol/g, mid-distal sigmoid: 1965 (484)). A clear differential distribution of regulatory peptides was thus shown in the region studied. A possible role is suggested for NPY and VIP containing nerves in the effector control of the human internal anal sphincter.
[Is the bone marrow the only source of endogenous odor components? A contribution on immunopsychology].
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Cyclosporine A induced lipid peroxidation in microsomes and effect on active and passive glucose transport by brush border membrane vesicles of rat kidney.
The in vitro effect of cyclosporine A (CsA) on lipid peroxidation (LPO) in rat renal microsomes were investigated either with different CsA concentrations (0.001 to 1.5 mg/ml) or for different periods of time (0.5 to 3 h). Furthermore the influence of this drug on glucose uptake by rat renal brush border membrane vesicles (RBBMV) prepared from renal cortical slices which were preincubated with CsA for 1 or 3 h was studied. CsA caused a time- and concentration-dependent increase of malondialdehyde production in renal microsomes. LPO was inhibited by addition of the radical scavenger alpha-tocopherol. Regarding the CsA effect on the vesicular glucose uptake, an increase in the passive influx constants of L-glucose and a decrease in the maximal transport rates of the sodium-dependent D-glucose uptake were found as compared to the corresponding control values. The apparent affinities of D-glucose to the glucose transporter were slightly lowered after incubation of slices in a CsA containing medium. The results of the present study suggest that CsA causes LPO in renal microsomes and that this LPO is due to membrane damage by CsA as shown by alternations of active and passive glucose uptake by RBBMV.
The vascularization of the peripheral nerve of chicken and rat.
The vascular system of the sciatic nerve of chicken and rats was examined by means of the microcorrosion casting technique and freeze-broken specimens. The main epineural vessels form two lateral and interfascicular vascular bundles which anastomose with one another and also with the peri- and endoneural plexuses. On epi- and perineural vessels one can find morphological correlates for regulative means such as sphincters. Even the endoneural vessels depict numerous anastomoses. The proximity of the vessels as well as the great number of anastomoses suggests a considerable compensatory potential with an adaptable perfusion rate in case of a partial breakdown of a plexus.
The surface compartment model: a theory of ion transport focused on ionic processes in the electrical double layers at membrane protein surfaces.
This paper is a review of the surface compartment model of ion flow across the channels of natural membranes. The model emphasizes the role of electrical double layers in ion transport and is derived from first principles. When the surface compartment model is applied to the membrane of an excitable cell, (e.g., the squid axon), one can calculate voltage clamp currents that are similar to those observed in the sodium and potassium channels of excitable membranes. The difference in the selectivity of the two types of ion channel appears to be determined by the difference in gating current, and is in line with measurements on the sodium and potassium channels of squid axon. These results indicate that there is a kinetic basis for the selectivity of voltage gated channels and suggest that other types of channels may operate by related mechanisms. The focus of the surface compartment model on charged surfaces has led to a description of the channel opening/closing process in terms of surface free energy, assuming an analogy to the aggregation/disaggregation reactions in oligomeric proteins. The opening of voltage gated oligomeric channels can be formulated in terms of variations in the surface free energy that are triggered by changes in the surface charge density. On this basis, it is possible to introduce gating phenomena into the surface compartment model and to couple the channel processes with charge movements.
[Infrared thermography in functional disorders of the axial skeleton].
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Measurement of key enzyme activities involved in the metabolism of platelet activating factor.
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Trophoblast does not cause the cytotoxic T lymphocyte generation due to the lack of ability to stimulate interleukin-2 production.
Trophoblast was demonstrated to be unable to cause the production of interleukin-2 (IL-2) by allogeneic splenocytes in vitro in two ways: 1) The addition of lymphocyte-trophoblast culture-supernatant (LTC-SN) did not stimulate the proliferation of IL-2 dependent cytotoxic T lymphocyte (CTL-L cells; 2) When responder cells were cultured with heat-treated splenocytes (usually no CTL generation) an increase of CTL formation could be seen in the presence of mixed lymphocyte culture-supernatant (MLC-SN) but not of SN from the cultures in which trophoblast cells served as stimulators. In parallel, the trophoblast cells were found to be very poor stimulators of alloreactive CTL. The addition of interleukin-2-enriched media resulted in a significant amplification of trophoblast-induced CTL generation. The resulting killing lymphocytes were capable of destroying the only specific targets, did not lyse syngeneic target cells, and could not be generated in the absence of allogeneic trophoblast. The incubation of these lymphocytes with anti-Thy 1.2 monoclonal antibody in the presence of complement eliminated their killing effect. Lack of class II antigenic determinants on the surface of trophoblast and/or local immunosuppression of IL-2 production by trophoblast cells seem to be responsible for nondelivery of helper factor, which is essential for CTL production.
[Changes in the thermogram of the body surface induced by acupuncture in human beings].
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The vascularization of the vertebral column of rats.
The intrinsic and extrinsic blood supplies of the vertebral column of rats have been examined by corrosion cast with Mercox CL2B(R). The close functional and topographic relationship of vessels to supplied structures were exposed by fractionated maceration of the soft tissues. The segmental arteries diverge into an anterior, median and posterior group with various anastomoses between their branches. Vertebral bodies and intervertebral discs are preferably supplied by branches of the anterior and median section. The vessels reaching the vertebral body from the dorsal side diverge in a treelike branching mode into the direction of the vertebral endplate. The venous drainage takes place by the segment-overlapping internal and external vertebral venous plexuses. Bloodflow regulating sphincters can be identified within all parts of the arterial and venous system. This fact seems to be of great importance regarding pathophysiological processes of degeneration and likewise regeneration even of the intervertebral discs.