Caudal end of the rat spinal dorsal horn

We have previously demonstrated that the transformation of the caudal spinal cord through the conus medullaris to the filum terminale takes place in three steps. In the conus medullaris the twin layers of CGRP-immunoreactive and IB4-labeled primary afferent fibers as well as the translucent portion of the superficial dorsal horn equivalent to the substantia gelatinosa discontinue before the complete removal of the dorsal horn. Parallel with these changes VGLUT1-immunoreactive myelinated primary afferent fibers arborize not only in the deep layers but also in the entire extension of the remaining dorsal horn, while scattered CGRP fibers still remains at the margin of and deep in the dorsal horn. PKCgamma-immunoreactive dorsal horn neurons discontinue parallel with the disappearance of the IB4-labeled nerve fibers. These observations suggest that in the dorsal horn certain neurons are linked to the substantia gelatinosa, while others are substantia gelatinosa-independent neurons.     

Adjuvant-dependent modulation of Th1 and Th2 responses to immunization with beta-amyloid

The role of adjuvant on the T(h)1 and T(h)2 immune responses to Abeta-immunotherapy (Abeta(42 )peptide) was examined in wild-type mice. Fine epitope analysis with overlapping oligomers of the Abeta(42) sequence identified the 1-15 region as a dominant B cell epitope. The 6-20 peptide was recognized only weakly by antisera from mice administrated with Abeta(42) peptide formulated in complete Freund's adjuvant (CFA), alum or TiterMax Gold (TMG). However, mice immunized with Abeta(42) mixed with QS21 induced a significant antibody response to the 6-20 peptide. The only T cell epitope found was within the 6-28 sequence of Abeta(42). QS21 and CFA induced the strongest humoral response to Abeta, alum was intermediate, and TMG the weakest adjuvant. Analysis of antibody isotypes specific for Abeta indicates that alum induces primarily T(h)2-type immune response, whereas TMG, CFA and QS21 shift the immune responses toward a T(h)1 phenotype. Stimulation of splenocytes from Abeta-immunized mice with Abeta(40) peptide induced strikingly different cytokine expression profiles. QS21 and CFA induced significant IFN-gamma, IL-4 and tumor necrosis factor-alpha expression, whereas alum induced primarily IL-4 production. As T(h)1-type immune responses have been implicated in many autoimmune disorders, whereas T(h)2-type responses have been shown to inhibit autoimmune disease, the choice of adjuvant may be critical for the design of a safe and effective immunotherapy for Alzheimer's disease.     

Responsiveness of the ANP providing system to volume load in conscious dogs

We examined in detail changes in arterial plasma ANP concentration in response to volume load in conscious dogs. In a 5-min volume load experiment, 18 ml/kg of isosmotic and isooncotic 3% Dextran 40 in saline was infused over a period of 5 min. Mean left atrial pressure (MLAP) increased transiently by 7.6±0.9 mm Hg. Plasma ANP level (P-ANP) did not significantly increase. Assayed P-ANP levels were corrected for hemodilution. Corrected P-ANP (C-ANP) significantly increased from 206±17 to 348±34 pg/ml. However, the level of C-ANP did not reach a steady state. No significant linear correlation was found between increases in MLAP and normalized C-ANP. In a 45-min volume load experiment, the elevated level of MLAP caused by the 5-min volume load was maintained for 40 min by supplemental infusion. C-ANP significantly increased from 196±18 pg/ml to 435±73 ng/ml. The level of C-ANP reached a steady state. A close linear correlation was observed between increases in MLAP and normalized C-ANP. However, the peak time of C-ANP lagged 10 min behind MLAP. These results indicate that it takes 10 min for P-ANP to reach a steady state in fully responding to a volume load, and that the long-term volume load is a prerequisite to the response of the ANP providing system.     

The N-terminal flanking region of the invariant chain peptide augments the immunogenicity of a cryptic "self" epitope from a tumor-associated antigen

The N-terminal flanking region of the invariant chain peptide termed CLIP appears to have superagonistic properties interacting with the T cell receptor and the MHC class II molecule at or near the binding site for the bacterial superantigen Staphylococcal enterotoxin B (SEB). The present studies explored the hypothesis that the N-terminal segment of CLIP can augment the immunogenicity of cryptic "self" tumor-associated antigens. A chimeric construct of an MHC class II binding peptide from the c-erb oncogene (Her-2/neu) containing the N-terminal flanking region of CLIP elicited potent antitumor activity against a Her-2/neu-positive tumor in a rat model system. Comparatively, the unmodified parent peptide was ineffective. The induction of effective antitumor immunity, however, required presentation of the chimeric peptide construct on irradiated tumor cells or the peptide construct in concert with a Her-2/neu MHC class I-restricted peptide from Her-2/neu. As revealed by adoptive transfer studies, effective protective antitumor immunity in this setting required the CD4 T helper subset. Additionally, in vitro analysis revealed that immunization with the parent peptide resulted in a weak immune response to the unmodified peptide consisting of both type 1 (IL-2, IFN-gamma) and type 2 (IL-4, IL-10) cytokine-producing cells analyzed by RT-PCR (qualitative and quantitative) and by limiting dilution assay. Comparatively, immunization with the chimeric construct elicited a potent immune response to the parent peptide with predominantly type 1 cytokine-producing cells. Taken together, the results suggest that immunization with the chimeric Her-2/neu peptide induced protective antitumor immunity. Associated with this immunization strategy was the enhancement of a type 1 cytokine response.     

Geroprotective effect of Ala-Glu-Asp-Gly peptide in male rats exposed to different illumination regimens

Exposure of male rats to permanent or natural illumination of North-Western Russia accelerated their death in comparison with animals exposed to standard (12 h) light. Permanent illumination promoted the development of spontaneous tumors in comparison with the standard photoregimen. Injection of epithalone (synthetic Ala-Glu-Asp-Gly peptide; subcutaneously 0.1 μg/rat 5 times a week from the age of 4 months until natural death) virtually did not change the mean lifespan of male rats, but was associated with a significant (p<0.05) normalization of population aging rate and hence, time of mortality rate doubling in groups exposed to natural or constant illumination. Epithalone injected to rats exposed to any photoregimen significantly inhibited the development of spontaneous tumors, primarily testicular leydigomas and leukemias. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 4, pp. 455–460, April, 2008     

Heritable dentin defects: Nosology,pathology, and treatment

Heritable dentin defects have been divided into 2 main categories: dentinogenesis imperfecta (DI) and dentin dysplasia (DD). Recent studies have shown that they share many features in common. Of the connective tissue diseases, only osteogenesis imperfecta (OI) has been linked to these disorders. So far, no definitive relation between the type of OI and the dental involvement can be established. Familial occurrence of DI with OI cannot be comprehensively explained by mutations in type I collagen genes. No information about the gene defects in DD is available. At the ultrastructural level, the organization of the normally cross-striated collagen fibers in the dentin matrix varies markedly in patients affected by DI.     

Urodilatin: a new peptide with beneficial effects in the postoperative therapy of cardiac transplant recipients

Summary Renal failure after heart transplantation (HTx) still remains a serious problem, especially when cyclosporin A is used for immunosuppression in the early postoperative therapy. To preserve good renal function without reducing immunosuppressive cyclosporin A treatment, we administered urodilatin (CDD/ANP-95-126) in a long-term, low-dose infusion in addition to the usual medication after heart transplantation. From November 1990 to June 1991, 51 patients (46 male and 5 female; mean age 48 years) were treated with a 620 ng/kg bw·min infusion for 96 h after HTx. The renal function and hemodynamic parameters of these urodilatin-treated patients were compared in this sequential study with 40 patients (33 male and 7 female; mean age 49 years) who had undergone HTx previously from May to November, 1990, as controls. In this phase IIa study, both groups did not differ significantly with respect to age, sex, indication for HTx, and preoperative renal function. In comparison with controls patients treated with urodilatin had a significantly better renal function: a reduction in the peak plasma creatinine (PC values day 4 : 1.5 ± 0.11 vs. 2.19 ± 0.19 mg/dl; P = 0.002), a lower peak serum urea (SU values day 4 : 109 ± 8 vs. 154.7 ± 8.94 mg/dl ; P = 0.0036), and a lower incidence of hemodialysis (6% vs. 10%) were observed. Adequate diuresis was maintained in spite of the reduction of furosemide by more than 60% (P = 0.005) on each day of urodilatin infusion in comparison with controls. The mean central venous pressure was significantly lower by about 50% (P = 0.02) during the administration of urodilatin in spite of reduced vasodilator medication with nitroglycerin. From this phase IIa study, we may conclude that urodilatin could be an important drug in intensive care treatment. For patients undergoing HTx, this peptide seems to be indicated for the improvement of renal function and cardiovascular status, especially in postoperative therapy using high-dose cyclosporin A treatment.Abbreviations ACE angiotensin converting enzyme - ANP atrial natriuretic polypeptide - ATG antithymocyte globulin - bpm beats per minute - bw body weight - CDD cardiodilatin - CDD/ANP-99-126 circulating form of vasorelaxant cardiac peptide - CHD coronary heart disease - CyA cyclosporin A - DCM dilated cardiomyopathy - GLM general linear model - hANP human atrial natriuretic polypeptide - HTx heart transplantation - NTG nitroglycerine - PC plasma creatinine - SU serum urea - SAS statistical analysing system     

Endogene Natriuretische und Ouabain-ähnliche Faktoren

Summary The existence of an endogenous natriuretic hormone and ouabain-like factors (OLF) has been postulated for many years. This postulate was based on our original observation that a small M.W. fraction in the serum after acute expansion of the extracellular fluid volume (ECFV) not only exhibited natriuretic activity but also inhibited the Na-K-ATPase enzyme in vitro similar to ouabain. Since then, numerous studies confirmed the presence of OLFs in serum, urine, cerebrospinal fluid, and various organs including the heart and hypothalamus. Some of these OLFs are well-known endogenous compounds, such as free unsaturated fatty acids, which inhibit in vitro transmembranous sodium transport, Na-K-ATPase and³H-ouabain binding to its membrane receptor or crossreact with digoxin antibodies. Chemically yet undefined OLFs of potentially hypothalamic origin were detected in various models of experimental and clinical hypertension and are suggested to play a pathophysiological role especially in salt- and volume-dependent forms of hypertension. Our results show that OLFs isolated from the urine of salt-loaded healthy subjects strongly enhance basal and vasopressin-stimulated release of calcium in vascular smooth muscle cells and platelets similar to the effects we had observed with endothelin. This urine fraction also exhibits natriuretic activity which increases in parallel with sodium intake. Further chromatographic separation and amino acid analysis confirmed the peptidic nature (M.W.<1000) of the natriuretic factor(s). However, the two biological activities, namely natriuretic and ouabain-like activities, reside in distinct and chemically different compounds. In face of the previous discovery of the atrial natriuretic peptides (ANP) it is of special interest that very recent observations strongly suggest a natriuretic factor of non-cardiac origin to play an important role in the natriuresis that follows ECFV expansion. In addition, numerous experimental data point to an interaction between the ANP and OLF systems. They should stimulate once again the final identification of these yet unknown endogenous natriuretic and ouabain-like factors.

Die in dieser übersicht zitierten eigenen Untersuchungen wurden von der Deutschen Forschungsgemeinschaft, Bonn, dem Ministerium für Wissenschaft und Forschung des Landes Nordrhein-Westfalen (FA-2914, FA-8871, IVA6-402-046-87), Düsseldorf, und der Konrad-Adenauer-Stiftung, Bonn, unterstützt     

Cervical tissue uptake of all-trans-retinoic acid delivered via a collagen sponge-cervical cap delivery device in patients with cervical dysplasia

The present study was undertaken to evaluate the systemic absorption and cervical tissue uptake of all-transretinoic acid (TRA), delivered via a collagen spongecervical cap delivery device in patients with intraepithelial cervical dysplasia. Ten patients with histologically proven mild or moderate cervical dysplasia were included in this pharmacologic study. The two TRA concentrations (0.05% and 0.372%) selected for study represent the starting and maximally tolerated doses used in phase I clinical trial. All-trans-retinoic-11-³H acid (³H-TRA, 500 Ci) was used to facilitate cervical tissue uptake studies. Cervical biopsies and post-treatment blood samples were obtained from each patient after TRA exposure. The uptake of TRA into cervical tissues four hours after drug administration was significantly increased at the maximally tolerated TRA dose. There was a rapid decrease in cervical tissue concentration of TRA at the 0.372% dose between 4 and 24 h after drug exposure, suggesting a relatively short elimination half-life of TRA in cervical tissues. HPLC analysis of post-treatment blood samples indicate that there was no systemic absorption of TRA after local cervical administration.