EFFECT OF A LARGE DOSE OF THYROTROPHIN RELEASING FACTOR ON PITUITARY AND THYROID FUNCTION IN PATIENTS WITH PARKINSONISM

Thyrotrophin releasing factor (TRF) was given intravenously in doses of 0.5 mg and 20 mg to six patients with Parkinsonism treated with l -dopa. Plasma thyrotrophin (TSH), prolactin, luteinizing hormone (LH), follicle stimulating hormone (FSH), thyroxine (T4) and triiodothyronine (T3) were measured before and after TRF infusion. The observation that FSH and LH did not change in response to either dose of TRF confirmed specificity of the effects of TRF for certain anterior pituitary functions. The plasma TSH and prolactin levels achieved after 20 mg TRF were considerably greater and were maintained longer than those after 0.5 mgTRF. However, despite a seven fold increase in the overall TSH response, the T4 and T3 responses to 20 mg TRF were not significantly greater than those to 0.5 mg TRF. The explanation for this discrepancy between immunoreactive TSH levels and apparent biologic effect is unclear.     

DESIGN,SYNTHESIS AND 13 C- AND 1 H-N.M.R. INVESTIGATION OF A CYCLIC OCTAPEPTIDE TO MIMIC THE ZINC-BINDING SITE OF CARBOXYPEPTIDASE A

Considering the three-dimensional structure and the native Zn(II)-binding ligands of carboxypeptidase A followed by extensive model building, a cyclic octapeptide, cyclo-(Gly-L-Glu-Gly-Gly-L-His-Gly-L-His-Gly) was designed to mimic the Zn(II)-binding site of carboxypeptidase A. The cyclic octapeptide was prepared by high dilution technique from the corresponding linear octapeptide, N-Boc-Gly-γ-OBu^t-L-Glu-Gly-Gly-L-His-Gly-L-His-Gly-OBzlNO₂ via the azide method. The linear octapeptide was obtained by coupling of the two tetrapeptide fragments: N-Boc-Gly-γ-OBu^t-L-Glu-Gly-Gly-ONp and L-His-Gly-L-His-Gly-OBzlNO₂. The cyclic peptide was purified to homogeneity by the method of countercurrent distribution. The product obtained was both ninhydrin negative and Pauli's reagent positive. Further confirmation of this material was obtained by the proper amino acid ratio of its acid hydrolysate and by the proton magnetic resonance spectrum in which the various kinds of protons of this peptide were accounted for. A detailed ¹³C- and ¹H-n.m.r. investigation was undertaken to determine the Zn(II)-binding ligands of the cyclo-octapeptide. The assignments for all the resonances were attempted by pH titration, by employing homonuclear decoupling experiments and by synthesis of cyclo-octapeptide containing specifically deuterated amino acids cyclo-(Gly-L-Glu-Gly-d₂-Gly-d₂-L-His-Gly-L-His-Gly). Titration results of Zn(II) bound form of the cyclic peptide showed the presence of a 1:1 complex. Upon Zn(II)-binding, the proton resonances were shifted downfield, the largest change being that of the histidine residues and more particularly C(2)-H protons. The chemical shifts induced on glutamic acid residue were also observed for Glu CH₂γ. In the case of ¹³C resonances, the maximum change in chemical shift was observed in the histidine residues and especially in the imidazole ring upon complexation. Two methylenes of the glutamic acid residue showed a large change in chemical shift upon ligating to the metal ion. The most significant observation was the deshielding effect of the Glu COO^- group. The results demonstrate that Zn(II) binds both the imidazoles of the two histidine residues and the carboxyl side chain of the glutamic acid residue of the designed cyclic octapeptide.     

VJ REARRANGEMENTS OF THE TCRγ LOCUS IN PERIPHERAL T-CELL LYMPHOMAS: ANALYSIS BY POLYMERASE CHAIN REACTION AND DENATURING GRADIENT GEL ELECTROPHORESIS

Using Southern blotting for the diagnosis of clonality in peripheral T-cell lymphomas (PTCLs), analysis of the T-cell receptor (TCR) γ gene rearrangement was shown to be more informative than that of the TCR β gene rearrangement. In order to amplify every VJγ rearrangement, a polymerase chain reaction (PCR) procedure using newly designed GC-clamp primers has been developed. All primers can be mixed in a single multiplex PCR. PCR products are analysed by denaturing gradient gel electrophoresis (DGGE), providing tumour-specific imprints inasmuch as the procedure characterizes N sequence polymorphism at the VJ junctions. In a series of 30 PTCL cases, the PCR procedure demonstrated 27 cases to be clonally rearranged and failed in three cases. PCR was more accurate than Southern blotting, showing 47 rearranged γ alleles, four of which were undetectable on the Southern blot. When lymphomas were studied at different sites and at relapse, the DGGE pattern remained unchanged. In PTCL, the proposed PCR is helpful for the diagnosis and staging of the disease and should improve the follow-up monitoring. The undetectability of clonal rearrangements in a few cases is discussed in the light of concepts of lymphomagenesis and T-cell differentiation.     

The oro-dental phenotype in Prader–Willi syndrome: a survey of 15 patients

Background.  Prader–Willi syndrome (PWS) is a rare disorder caused by genetic defects in certain regions of chromosome 15q11–13. It is characterized by severe neonatal hypotonia and feeding problems, childhood-onset hyperphagia and obesity, short stature, facial dysmorphy, hypogonadism, learning and behavioural difficulties, and dental abnormalities.
Aim.  To describe the oro-dental phenotypic spectrum of patients with PWS.
Design.  Fifteen PWS patients (3–35 years of age) being followed at the Centre for Human Genetics of the University Hospital of Leuven were examined at the dental clinic of the same institution. Medical information collected included age at diagnosis, body mass index (BMI) and level of cognitive functioning. Oral, clinical and radiological evaluations were performed. Caries experience (cavitation level), dental erosion and salivary flow rates were assessed.
Results.  The 15 patients had dmft/DMFT scores ranging from 0 to 28, while nine were cavity-free. Those with severe caries experience also presented advanced dental erosion. BMI ranged from 16 to 42.6. There was no association between BMI and caries experience or erosive tooth wear. The PWS patients in our survey presented with a more favourable oral health status than those in previous studies. This might be due to early diet management or better oral hygiene during childhood or both.     

In Vivo and In Vitro Immunosuppressions in Mice by a 100–110-Kd Fraction From Boar Seminal Plasma

ABSTRACT: The activity of a 100–110-Kd immunosuppressive fraction (ISF), isolated from boar seminal plasma, was investigated in mice. In vitro, this fraction was found to inhibit a unidirectional mixed lymphocyte response and cell-mediated lymphocytotoxicity, as well as antisheep red blood cells (T-dependent) and antitrinitrophenylated lipopolysaccharide (T-independent) responses. The ISF also inhibited the macrophage phagocytosis of erythrocytes coated with IgG antibodies, but it did not suppress the natural killer activity. In vivo, ISF was found to lower both the primary responses to T-dependent and to T-independent antigens. Trypsin or pronase digestion of ISF provided active molecules of 30 Kd or 2–5 Kd respectively, thus showing that the activity is due to a protein. This ISF factor, capable of suppressing a wide variety of immune functions and remaining active after cleavage by proteases, could play a role in the lack of immune response against the spermatozoa present in the sow genital tract after intercourse. The use of this factor as a therapeutic agent in humans could eventually be considered after further molecular characterization.     

THE EFFECT OF EXPERIMENTAL RENAL FAILURE ON TOLFENAMIC ACID DISPOSITION IN THE DOG

The pharmacokinetic disposition of tolfenamic acid, an NSAID, after a single administration of tolfenamic acid (4 mg kg⁻¹) by the intravenous (IV) route was compared in eight dogs before and after a surgically induced renal failure. Renal impairment was confirmed by a significant increase ( p <0·001) of water intake, urine volume, and urea and creatinine plasma concentration. PAH and inulin clearances decreased after surgery from 15·2±4·2 to 9·5±0·8 mL kg⁻¹ min⁻¹ ( p <0·05) and from 4·37±1·15 to 2·43±0·88 mL kg⁻¹ min⁻¹ ( p =0·067), respectively. After surgery, clearance of TA was significantly ( p <0·001) increased, from 2·22±1·68 to 3·59±1·81 mL kg⁻¹ min⁻¹. There was no modification of the steady-state volume of distribution ( p >0·05) and the mean residence time was significantly decreased from 606±199 to 373±302 min ( p <0·05). No variation of binding to plasma proteins (<99%) was observed. These results suggest that renal insufficiency could increase hepatic metabolism and/or alter the enterohepatic cycle of TA. © 1997 by John Wiley & Sons, Ltd.     

A population survey of bowel habits in urban Swiss men

The aim of this study was to determine the prevalence of symptomsrelated to constipation in urban Swiss men and to identify associatedsociodemographic factors and health habits. A sample of 773men aged between 35 and 74 years randomly selected from theGeneva population answered a questionnaire on bowel habits duringa personal interview in a mobile epidemiological unit. ‘Constipation’was reported by more than 6% of subjects, difficulties in stoolevacuation by approximately 5% and less than three stools perweek by approximately 2%. These symptoms appeared less prevalentin subjects with post-baccalaureate education (the excess prevalenceof self-reported constipation, difficulty in stool evacuationand frequent daily defecation was greater than 5%). Smokerswere more likely to have a frequency of 3–7 stools perweek and were less affected by frequent daily defecation. Self-reportedconstipation was more prevalent in subjects with a higher dietaryfibre intake. No statistically significant effects of age, nationality,dietary fat or physical activity were observed. These resultsare consistent with national surveys in US populations. Factorsrelated to socioeconomic status or education may be a causeof constipation in men, but they still need to be elucidated.