The effect of nadroparine on coagulation mechanisms: ultrastructural analysis.

Low molecular weight heparins are widely used in the prophylaxis and treatment of thrombotic disorders. The effect of low molecular weight heparins on coagulation was examined ultrastructurally in an animal model. A test and a control group was formed, each consisting of five rabbits. Nadroparine (225 Institute of Chaoy Unit/kg twice daily) was applied to the test group for 10 days. The control group received 1 ml saline solution subcutaneously. Blood and vascular tissue samples collected at the end of the 10th day were evaluated under a JEM 100 B electron microscope. Platelet degranulation and agglutination was observed in the control group. Fibrin materials were detected in the cytoplasms and surroundings of degranulated platelets. Erythrocyte accumulation was remarkable on the vascular endothelium with intact coagulation periods. In the test group, outer membranes of platelets, hyalomere, and granular structures in the granulomeres were detected to be nearly intact. There were rare erythrocytes in the large vascular lumens. The aggregation phase had occurred but no agglutination was detected. Nadroparine seems to preserve consistency of lipoprotein membranes of platelets and granular structures containing enzymes, which contribute to the coagulation mechanisms.     

Ligneous periodontitis and gingival antioxidant status: report of two cases.

Ligneous periodontitis (LP) is a rare periodontal disease in which plasminogen deficiency and fibrin deposition both play a part, resulting in characteristic gingival enlargement and periodontal breakdown. Recent data suggest that oxidant/antioxidant changes are significant in the pathology of oral diseases. This study examines the gingival histopathology in 2 cases with LP. To examine the antioxidant (AO) status, the activity of the major AOs glutathione (GSH), catalase (CAT), and glutathione S-transferase (GST) and the malondialdehyde (MDA) levels, a product of lipid peroxidation, were measured and compared with healthy control subjects. The histopathologic examination of the gingiva revealed subepithelial fibrin accumulation and irregular extensive downward proliferation of the epithelium. Biochemical analysis showed that the CAT, GST, and MDA levels were higher in LP patients than in the control subjects, and the GSH level was lower. Our preliminary findings show that in LP, the AO capacity of the gingiva changes or decreases and lipid peroxidation increases, which suggests that oxidative stress is involved in the pathology of the periodontal breakdown observed in this disease.     

The significance of extracellular GABA in the substantia nigra of the rat during seizures and anticonvulsant treatments

The effects of the anti-epileptic drugs valproic acid and gamma-vinyl-GABA j(vigabatrin) on the extracellular content of GABA was determined by microdialysis. Probes were implanted in the substantia nigra reticulata (SNR) of rats. It was found that gamma-vinyl-GABA (1000 mg/kg) induced a 4–6-fold increase in the extracellular content of GABA. This increase lasted for at least 72 h. PTZ-induced convulsions were partly antagonized by the GVG treatment. The increase of extracellular GABA after gamma-vinyl-GABA was not affected by infusion of tetrodotoxin. In contrast valproic acid (200 mg/kg), although effective in preventing pentylenetetrazol (PTZ)-induced convulsions, did not affect extracellular GABA in the SNR. PTZ-induced convulsions did not modify extracellular GABA, neither in control rats nor in valproic acid or gamma-vinyl-GABA pretreated animals. The results do not support the idea that extracellular GABA in the SNR plays a significant role in anti-convulsive treatment. However, the present data can also be interpreted that extracellular GABA, as sampled by microdialysis, is not a reliable marker for GABA release.     

Polyether Synthesis through Reductive Etherification Reaction Strategy

The reductive etherification reaction (RER) of carbonyl groups (aldehydes or ketones) through silane as a reducing agent together with Bronsted or Lewis acid affords the synthesis of symmetrical and unsymmetrical ethers. This strategy is applied at the macromolecular level for the first time in 1993, and isophthalaldehyde is self-polymerized in the presence of triethylsilane (Et₃SiH)/ tritylperchlorate (TrClO₄) to yield polyethers with low to moderate molecular weights. Next, the polyethers with alternating structures are achieved by reacting isophthalaldehyde with bis(trimethylsilyl) ethers or diols as comonomers using reducing agent silane and Lewis acid. Moreover, in recent years, it is shown that polyether synthesis and post-polymerization modification (PPM) of polymers proceeds smoothly and effectively with the RER strategy in the presence of chlorodimethylsilane (CDMS), which acts as both a reducing agent and a Lewis acid.     

Anaphylactic reaction to polyethylene‐glycol conjugated‐asparaginase: Premedication and desensitization may not be sufficient

In hypersensitive reactions to native L‐asparaginase, either premedication and desensitization or substitution with polyethylene glycol conjugated asparaginase (PEG‐ASP) is preferred. Anaphylaxis with PEG‐ASP is rare. An 8‐year‐old girl and a 2.5‐year‐old boy, both diagnosed as having acute lymphoblastic leukemia, presented with native L‐asparaginase hypersensitivity and substitution with PEG‐ASP was preferred. They received a premedication (methylprednisolone, hydroxyzine and ranitidine) followed by desensitization with PEG‐ASP infusion. Both patients developed anaphylaxis with peg‐asparaginase. These are the first reported cases of anaphylactic reaction to PEG‐ASP, despite the application of both premedication and desensitization. Anaphylaxis with PEG‐ASP is very rare and premedication and desensitization protocols may not prevent these hypersensitive reactions.     

CYP1A1 gene polymorphism and polycystic ovary syndrome

The aim of this study was to assess the rates of variant alleles of cytochrome P4501A1 (CYP1A1) in patients with polycystic ovary syndrome (PCOS). It was designed as a case-control study in Hacettepe University, Faculty of Medicine, Department of Obstetrics and Gynecology and Genetics. Forty-eight patients with PCOS served as the study group. Ninety-six regularly cycling women with no clinical and biochemical evidence of hyperandrogenism and polycystic ovary appearance served as the controls. The CYP1A1 variant alleles of all patients were determined via polymerase chain reaction. The rate of the CYP1A1 isoleucine (Ile)/valine (Val) allele was significantly higher in patients with PCOS than in the controls (OR: 7.8, 95% CI: 3.45-17.52, P < 0.001). However, there was no statistically significant difference in the distribution of Val/Val genotype (OR: 4.0, 95% CI: 0.60-26.73). The rate of any Val genotype (Ile/Val or Val/Val) was significantly higher in patients with PCOS compared with the control group (OR: 7.4, 95% CI: 3.33-16.46, P < 0.001). In conclusion, the patients with PCOS had a 7.8-fold higher frequency of CYP1A1 Ile/Val genotype and a 7.4-fold higher frequency of CYP1A1 of any Val genotype (Ile/Val or Val/Val).     

Factors affecting live birth rate in intrauterine insemination cycles with recombinant gonadotrophin stimulation

The objective of this cross-sectional study was to identify the prognostic factors that influence the outcome of ovarian stimulation with intrauterine insemination (IUI) cycles using gonadotrophins in couples with unexplained and mild male-factor subfertility. A total of 838 cycles in 456 women with unexplained and mild male-factor subfertility attending a university-based infertility clinic was evaluated. Of these cycles, 139 resulted in pregnancy (16.6% per cycle) and 96 out of 98 ongoing pregnancies resulted in live term birth. Live birth rate per patient and per cycle was 21.1% and 11.4%, respectively. Multivariate logistic regression analysis demonstrated that duration of infertility (P = 0.034), type of infertility (P = 0.003), aetiology of infertility (P = 0.004), number of treatment cycles (P = 0.0001) and number of dominant follicles before human chorionic gonadotrophin (HCG; P = 0.024) were significant independent factors to predict clinical pregnancy. The duration of infertility (P = 0.043), number of treatment cycles (P = 0.0001) and number of dominant follicles before HCG (P = 0.024) were significant independent factors to predict live birth. In conclusion, for subfertile couples having shorter duration of subfertility, multifollicular response to gonadotrophins and in their first treatment cycle are more likely to succeed a live birth with IUI treatment using recombinant gonadotrophins.     

The effect of temporary hemiepiphyseal stapling on the growth plate: a radiologic and immunohistochemical study in rabbits

The purpose of this study was to investigate the effect of temporary hemiepiphyseal stapling on the bone geometry and proliferative activity of the physis in immature rabbits. Proximal medial epiphyseal stapling of the right tibia was performed in 46 6-week-old New Zealand white rabbits. The rabbits were assigned randomly into two groups. In group 1, the staples were inserted extraperiosteally and the rabbits were killed at the end of 3 weeks. In group 2, the staples were fixed subperiosteally (group IIA) or extraperiosteally (group IIB), the staples were removed at the end of 3 weeks, and the rabbits were killed at the end of 6 weeks. The articular line-diaphysis angle (ALDA) was significantly increased with 3 weeks of stapling. After the removal of staples, while ALDA continued to worsen in group IIA, it improved in group IIB. Bone was observed to bridge the physis in group IIA. However, the proliferative activity of the physis continued. Temporary hemiepiphyseal stapling is a safe and effective method for control of physeal growth of long bones before skeletal maturity. However, it is of paramount importance not to disturb the periosteum during stapling.     

Glycosaminoglycans in childhood urinary tract infections

It has been suggested that urinary glycosaminoglycans (GAGs) form a natural defense mechanism against urinary tract infections (UTIs). This study investigated whether urinary GAGs play a role in pediatric UTIs, and whether urinary GAG level can be used to differentiate upper UTI from lower UTI. Forty-one children with UTIs (33 girls and eight boys; mean age 5.4+/-3.7 years) and 46 age- and sex-matched healthy children (35 girls and 11 boys; mean age 6.6+/-3.9 years) were included in the study. Urinary GAG levels were measured at the onset of acute infection and after a 10-day course of antibiotic treatment. Group GAG findings were compared, and comparisons were also made with the patients divided according to sex and according to UTI type (upper versus lower). The mean urinary GAG level in the patient group at the onset of acute infection (pretreatment) was significantly higher than the mean level in the control group (132.2+/-104.8 mg/g vs 42.2+/-27.1 mg/g creatinine, respectively; P <0.01). In the patient group, the mean urinary GAG level after antimicrobial therapy was significantly lower than the pretreatment level (75.9+/-52.1 mg/g vs 132.2+/-104.8 mg/g creatinine, respectively; P <0.01). However, the mean post-treatment level was still higher than the mean level in the controls ( P <0.05). There was no significant difference in urinary GAG levels when patients were categorized as upper versus lower UTI ( P >0.05). The study results suggest that GAGs play an important role in the pathogenesis of UTIs in children, and that measurement of urinary GAGs may be a valuable noninvasive method for evaluating UTIs in this patient group. However, this assay cannot be used to differentiate upper UTI from lower UTI in children.