Changes in human sperm chromatin stability during preparation for in-vitro fertilization

This study was designed to define the effects of sperm preparation on sperm chromatin stability in relation to in-vitro fertilization (IVF). Semen samples used for IVF-embryo transfer (ET) in the treatment of infertility due to tubal factors were studied. Cases with semen variables below reference limits in previous samples were excluded. Sperm were prepared by a swim-up technique employing either of two different tissue culture media, Ham's F-10 or Earle's balanced salt solution. Sperm chromatin stability was tested by exposure both to sodium dodecyl sulphate (SDS) only and SDS together with a zinc-chelating agent, disodium ethylene diamine tetraacetate (SDS-EDTA). Sperm head swell scores were defined under different experimental conditions and the relationship to sperm motility, morphology, fertilization rate and pregnancy occurrence was tested. No differences were seen between the chromatin stability of sperm from the original sample and that after swim-up preparation, neither immediately after completion of the swim-up procedure, nor at the time of insemination of ova. With time, the chromatin became more stable, which occurred to a similar extent both in the original sample and in swim-up preparations using Ham's F-10. Otherwise, sperm chromatin stability was unaffected by either of the two media used for swim-up. At higher incubation temperatures, decondensation in SDS was enhanced. Altogether, no correlation was found between sperm chromatin stability or enhancement of decondensation by temperature and the success of IVF treatment expressed in fertilization rates or pregnancies. The results are reassuring in that only small changes in sperm chromatin stability occurred during the preparation for IVF. As long as semen of presumably good quality is used, these changes in chromatin stability do not seem to be of clinical importance.     

Bacterial vaginosis: a double-blind randomized trial of the effect of treatment of the sexual partner

Summary. In a double-blind randomized controlled trial we assessed the effect of metronidazole treatment of the male partner on the recurrence rate of bacterial vaginosis. Women who fulfilled the diagnostic criteria for bacterial vaginosis were treated with metronidazole given in single doses of 2 g on days 1 and 3. The sexual partners were randomized to receive either the same dosage of metronidazole or a placebo. A total of 107 pairs completed the study. One week after the start of treatment 89% of the women considered themselves improved or cured and 93% no longer had the diagnostic criteria for bacterial vaginosis. At assessment 5 weeks after the treatment, 75% reported that they were cured or improved and the diagnostic criteria were not present in 73%. Treatment of the male partner did not affect subjective symptoms, clinical signs and isolation rates of Gardnerella vaginalis at 1 and 5 weeks after treatment.     

Effect of xylitol-, sucrose-, and water-rinses on the composition of human palatine gland secretions

Abstract – The chemical composition of stimulated human palatine secretions (HPS) was studied after rinsing with aqueous solutions of sucrose or xylitol, or with water only. Stimulation with water was associated with increased concentration levels of protein. The levels of sialic acids (per mg protein) and the specific arylamidase activities were simultaneously increased, within the physiologic range. In contrast to a previous report, these results indicate that HPS does contain arylaminopeptidases the activity of which is strongly increased by Cl⁻, The Cl⁻ -dependent activity was revealed when using N -L-arginyl-2-naphthylamide as substrate. The filter paper method used is recommended for collecting HPS for chemical analyses. In spite of the use of a relatively effective and versatile stimulation procedure, only one third of the subjects produced detectable HPS, Very poor secretion of HPS should perhaps be considered in subjects wearing total dentures.     

Harmonization of Animal Clinical Pathology Testing in Toxicity and Safety Studies

Ten scientific organizations formed a joint international committeeto provide expert recommendations for clinical pathology testingof laboratory animal species used in regulated toxicity andsafety studies. For repeated-dose studies in rodent species,clinical pathology testing is necessary at study termination.Interim study testing may not be necessary in long-durationstudies provided that it has been done in short-duration studiesusing dose levels not substantially lower than those used inthe long-duration studies. For repeated-dose studies in nonrodentspecies, clinical pathology testing is recommended at studytermination and at least once at an earlier interval. For studiesof 2 to 6 weeks in duration in nonrodent species, testing isalso recommended within 7 days of initiation of dosing, unlessit compromises the health of the animals. If a study containsrecovery groups, clinical pathology testing at study terminationis recommended. The core hematology tests recommended are totalleukocyte (white blood cell) count, absolute differential leukocytecount, erythrocyte (red blood cell) count, evaluation of redblood cell morphology, platelet (thrombocyte) count, hemoglobinconcentration, hematocrit (or packed cell volume), mean corpuscularvolume, mean corpuscular hemoglobin, and mean corpuscular hemoglobinconcentration. In the absence of automated reticulocyte countingcapabilities, blood smears from each animal should be preparedfor reticulocyte counts. Bone marrow cytology slides shouldbe prepared from each animal at termination. Prothrombin timeand activated partial thromboplastin time (or appropriate alternatives)and platelet count are the minimum recommended laboratory testsof hemostasis. The core clinical chemistry tests recommendedare glucose, urea nitrogen, creatinine, total protein, albumin,calculated globulin, calcium, sodium, potassium, total cholesterol,and appropriate hepatocellular and hepatobiliary tests. Forhepatocellular evaluation, measurement of a minimum of two scientificallyappropriate blood tests is recommended, e.g., alanine aminotransferase,aspartate aminotransferase, sorbitol dehydrogenase, glutamatedehydrogenase, or total bile acids. For hepatobiliary evaluation,measurement of a minimum of two scientifically appropriate bloodtests is recommended, e.g., alkaline phosphatase, gamma glutamyltransferase,5'-nucleotidase, total bilirubin, or total bile acids. Urinalysisshould be conducted at least once during a study. For routineurinalysis, an overnight collection (approximately 16 hr) isrecommended. It is recommended that the core tests should includean assessment of urine appearance (color and turbidity), volume,specific gravity or osmolality, pH, and either the quantitativeor semiquantitative determination of total protein and glucose.For carcinogenicity studies, only blood smears should be madefrom unscheduled sacrifices (decedents) and at study terminationto aid in the identification and differentiation of hematopoieticneoplasia.     

CONTACT ALLERGY TO CORTICOSTEROIDS

ABSTRACT: Contact dermatitis to topical corticosteroids does occur, although infrequently. Patch testing to the available steroids is recommended for patients with long-standing dermatoses which have responded poorly to topical steroids.     

The influence of age and sex on skin thickness, skin collagen and density

Forearm skin collagen, dermal thickness and collagen density were measured in a large number of normal subjects as a standard reference for future studies. Skin collagen decreased with age and was less in the females at all ages. There is a direct relationship between skin collagen and dermal thickness but variations in collagen density in disease limit the use of dermal thickness as a guide to changes in its collagen content.     

Genes encoding endothelin-converting enzyme-1 and endothelin-1 interact to influence blood pressure in women: the EVA study

BACKGROUND: Endothelin-1 (ET-1) is a potent vasoactive peptide that has been implicated in the regulation of basal vascular tone. Endothelin-converting enzyme-1 (ECE-1), the main enzyme responsible for ET-1 generation, may contribute to blood pressure (BP) control. A possible association between a polymorphism of the gene encoding ECE-1 (ECE1B C-338A) and BP values in untreated hypertensive women was recently reported. OBJECTIVE: We studied the influence of the ECE1B C-338A polymorphism on BP levels in 1189 subjects participating in the Etude du Vieillissement Artériel (EVA study), and looked for an interaction between this variant and a polymorphism of the ET-1 gene (EDN1 K198N). METHODS: The ECE1B C-338A polymorphism was genotyped in 491 men and 698 women; 477 men and 669 women could also be genotyped for the EDN1 K198N polymorphism. Associations between BP levels and genotypes were assessed by ANOVA; ANCOVA was used to control for covariates. RESULTS: We found an association between the ECE1B C-338A polymorphism and BP levels in women but not in men. Specifically, females homozygous for the A allele had significantly higher systolic, diastolic and mean BP levels (P = 0.01, 0.02, 0.006 respectively, after adjustment for age and body mass index). Genotyping of the EDN1 K198N polymorphism showed that this variant was not associated with BP values in either men or women, but interacted with the ECE1 variant to influence systolic and mean BP levels in women. CONCLUSION: Results from this large association study suggest that the genes encoding ECE-1 and ET-1 interact to modulate BP levels in women.     

Flexural Strength and Modulus Properties of Carbamide Peroxide–Treated Bovine Dentin

Background : The effects of carbamide peroxide bleach on tooth structure are uncertain.
Purpose : The purpose of this study was to investigate the effects of direct or indirect carbamide peroxide application on dentin flexural strength and modulus in vitro.
Materials and Methods : Dentin bars were machined from bovine incisors and treated with 10% carbamide peroxide for 6 h/d for 14 days. Four groups were created, with eight bars in each group: group 1–direct bleach application only; group 2–indirect bleach application only; group 3–direct bleach application followed by a 2–week storage in artificial saliva; group 4–direct bleach application followed by a 2-week storage in artificial saliva and daily topical fluoride treatments. The specimens' flexural strength and modulus were tested after 24 hours, and the results were compared with water controls using independent t -tests ( p < .05).
Results : Flexural strength results (in megapascals) for bleached versus control dentin (1 = 205 ± 26 vs 215 ± 14,2 = 257 ± 25 vs 261 ± 14,3 = 180 ± 22 vs 193 ± 36, 4 = 157 ± 18 vs 184 ± 11) were significantly lower in group 4 ( p = .005). Modulus results (in gigapascals) for bleached versus control dentin (1 = 10.7 ± 1.4 vs 12.2 ± 0.6, 2 = 14.2 ± 1.7 vs 14.4 ± 1.6, 3 = 10.0 ± 2.0 vs 10.9 ± 1.3, 4 = 9.0 ± 1.2 vs 11.1 ± 1.0) were significantly lower in groups 1 and 4 ( p = .013 and p = .003, respectively). There were no significant differences in strength and modulus results between the bleached and control dentin in groups 2 and 3. A direct application of carbamide peroxide to bovine dentin significantly decreased some dentin mechanical properties in vitro. An indirect application of carbamide peroxide to dentin did not significantly decrease dentin strength and stiffness.     

Isolated basal keratinocytes express pemphigoid gestationis antigen

Basal keratinocytes were isolated from epidermal cell suspensions prepared by trypsinization of normal human skin. Cells were identified as basal cells by their adherence to collagen and confirmed as basal cells by the presence of pemphigoid antigen. Using an indirect immunofluorescence assay, cells were found to express pemphigoid gestationis-related antigen. Sera from patients with pemphigoid gestationis reacted in one of two immunofluorescence patterns: either polar, in a pattern similar to that observed with bullous pemphigoid serum, or with uniform staining around the cell periphery. Pemphigoid gestationis-related antigen is expressed by isolated basal keratinocytes and is resistant to trypsinization. The heterogeneity of immunofluorescence patterns may correspond to the heterogeneity of antigen recognition by different patients with pemphigoid gestationis.