Effectiveness of topical zinc oxide application on hypertrophic scar development in rabbits.

BACKGROUND: The etiology, biology, prevention and effective treatment of hypertrophic scars have not exactly been defined. Topical zinc oxide application was shown to be effective in the treatment of proliferative scars. We studied the effectiveness of topical zinc oxide ointment in the prevention of hypertrophic scar development by using the rabbit ear hypertrophic scar model. METHODS: Circular full-thickness skin excisions were performed on both ears of 10 rabbits. The rabbits were divided into two groups and topical 40% zinc oxide ointment was applied daily to one ear and the ointment base was applied as placebo to the other ear. Scar samples were taken in the 3rd week in group 1 and in the 6th week in group 2. All of the specimens were divided into two halves: one half for histopathologic/histomorphometric examinations and the other half for biochemical studies. RESULTS: Application of topical zinc oxide ointment decreased clinical scar hypertrophy scores significantly (p=0.017) at 6th week in comparison with placebo. Topical zinc oxide also reduced nodule formation histopathologically at 6th week in comparison with placebo but this was not significant statistically (p>0.05). CONCLUSION: The findings of this study may have clinical implications on the management of human hypertrophic scars.

Protective role of 27bp repeat polymorphism in intron 4 of eNOS gene in lacunar infarction.

Association of the three potential endothelial nitric oxide synthase gene (eNOS) polymorphisms (T-786C in promoter region, G894T in exon 7 and tandem 27-bp repeats in intron 4) with an increased risk of lacunar infarction (LI) were investigated. Genotypes of 70 patients and 81 healthy controls were determined through PCR with or without RFLP. Flow-mediated dilatation (FMD) was performed to assess endothelial-dependent vasodilatation, whereas the endothelial-independent vasodilatation was assessed with nitroglycerin (NTG). Genotype distribution was significantly different between LI patients and controls for intron 4aa (alleles for four repeats), genotype frequency being 1.4% and 16.0%, respectively (odds ratio for additive effect, 0.47; 95% CI, 0.28-0.81; p=0.006). Haplotypes with the intron 4aa polymorphism were significantly higher in controls when compared with the LI group (p=0.001). Diminished FMD but normal NTG response confirmed that patients with LI have generalized endothelial dysfunction. Intron 4aa genotype of eNOS gene seems to be protective for isolated LI and the effect was potentiated by the absence of 786C polymorphism in any allele of the promoter region.

Identification of two novel arylsulfatase A mutations with a polymorphism as a cause of metachromatic leukodystrophy.

OBJECTIVE: Metachromatic leukodystrophy is a lysosomal storage disorder caused by the deficiency of arylsulfatase A or saposin B. Enzyme deficiency leads to the accumulation of sulfatide, which results in severe demyelination. METHODS: In this study, clinically suspected patients were diagnosed as metachromatic leukodystrophy by enzyme analysis using p-nitrocathecol sulfate as substrate. Eight exons and flanking regions of arylsulfatase A gene of patients were amplified by polymerase chain reaction and then subjected to single stranded conformational polymorphism analysis. Polymerase chain reaction products of suspicious exons in single stranded conformational polymorphism were purified from agarose gel and sequenced. RESULTS: DNA sequencing revealed two novel disease-causing missense mutations: the first one is 1568G-->A, 307Glu-->Lys in exon 5 which is together with a 2161C-->T, 391Thr-->Ser polymorphism in exon 7; and the second one is 1603G-->T, 318Trp-->Cys in exon 5. DISCUSSION: These two mutations are in highly conserved structural elements region of the arylsulfatase A protein. Thus, missense mutations 307Glu-->Lys in exon 5 and 318Trp-->Lys in exon 5 probably change the active site conformation by disrupting the sixth alpha helix and the twelfth beta-sheet structure of the arylsulfatase A protein, respectively, and cause deficiency in enzyme activity. This study provides the molecular basis for understanding the mechanism underlying metachromatic leukodystrophy.

Increased hexosaminidase activity in antipsychotic-induced extrapyramidal side effects: possible association with higher occurrence in bipolar disorder patients.

Dystonic movements and Parkinsonism are frequently seen in gangliosidoses and these conditions have been reported to modify dopaminergic plasticity. We investigated whether the activity of hexosaminidase, a type-two ganglioside (GM2) degrading enzyme, correlates with drug-induced extrapyramidal system (EPS) side effects in psychiatric patients. We compared hexosaminidase activity in the lymphocytes of 29 EPS-positive patients, 13 EPS-negative patients, and 30 healthy volunteers. The activities of A and B isoforms of hexosaminidase were higher in EPS-positive patients than EPS-negative patients and healthy controls. Multivariate analysis suggested an interaction with increased B isoform activity and EPS side effects in female bipolar disorder patients. Higher levels of hexosaminidase enzyme activity may explain the frequent occurrence of antipsychotic-induced extrapyramidal side effects in mood disorder patients.

Serum ribonuclease activity in the diagnosis of prostate cancer in men with serum prostate-specific antigen levels between 2.5 and 20 ng/mL.

OBJECTIVES: To evaluate the diagnostic value of serum ribonuclease activity for prostate cancer detection and to compare its performance with serum PSA. DESIGN AND METHODS: 111 subjects with serum PSA levels between 2.5 and 20 ng/mL underwent prostate biopsy. The diagnostic performance of serum ribonuclease activity, PSA, free PSA, complex PSA and PSA derivatives was studied in regard to discriminating prostate cancer from BPH. RESULTS: Of 111 patients, 27 (24.3%) were positive for prostate cancer. Median serum ribonuclease level in patients with prostate cancer was significantly higher than the non-cancer patients (21.3 U/mL vs. 6.6 U/mL, P < 0.001). Area under curve (AUC) values for ribonuclease activity level, PSA, f/tPSA and cPSA were 0.696, 0.514, 0.617 and 0.662, respectively. Of 27 patients with prostate cancer, radical prostatectomy was performed in 15. Of these 15 cases, four (26.7%) had clinical insignificant tumors; all with undetectable serum ribonuclease activity. When median values of various diagnostic parameters were compared in regard to predicting clinically significant and insignificant cancers, only serum ribonuclease activity was found to be significant. CONCLUSIONS: Although serum ribonuclease activity had no additional benefit beyond serum PSA in the diagnosis of patients with PSA levels between 2.5 and 20 ng/mL, it may be helpful to discriminate the clinically significant prostate cancers and thus select the proper treatment accordingly.

The effects of alpha-lipoic acid on nitric oxide synthetase dispersion in penile function in streptozotocin-induced diabetic rats.

Diabetes-induced erectile dysfunction is one of the most prevalent complications of diabetes in males. alpha-Lipoic acid (ALA) and its reduced form, dihydrolipoic acid, are powerful antioxidants. Data strongly suggest that, because of its antioxidant properties, ALA is particularly suited to the prevention and/or treatment of diabetic complications that arise from overproduction of reactive oxygen and nitrogen. The aim of this study was to investigate the localization of nitric oxide synthetase (NOS) in normal and diabetic rat cavernous smooth muscles and to examine the effects of ALA on them. Rats were divided into four groups: control, diabetic, diabetic plus ALA, and ALA only. Penile tissues were taken 15 days after drug application and examined histochemically and immunohistochemically. Comparison of the control and diabetic groups revealed that the axons of nerve cells were not identified with Masson trichrome in the diabetic group, whereas in the control group NOS localization and immunostaining (endothelial NOS [eNOS]) were normal. Diabetic rats administered ALA showed improvement in Masson trichrome, nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) and eNOS localization compared with untreated diabetic rats. Although there was no difference between the control group and the group administered ALA only, we observed an increase in NADPH-d and eNOS. In erection, eNOS and neuronal NOS (nNOS) may have a significant role. In pathologic conditions, erectile dysfunction may occur as a result of an increase in inducible macrophage-type NOS (iNOS). ALA plays an important role in treatment of erectile dysfunction by decreasing iNOS and increasing other isoforms of NOS.

Does serum hexosaminidase activity play a role in the diagnosis of strangulated bowel obstruction? An experimental study.

Strangulation is associated with an increased risk of mortality and morbidity in patients with mechanical bowel obstruction. The accurate and early recognition of the presence of strangulation is important to allow safe nonoperative treatment. A number of studies have shown that there was no single and reliable test to detect or exclude the presence of strangulation. The aim of this study was to evaluate the role of serum hexosaminidase (Hex) levels in recognition of strangulation in an experimental model of closed loop small bowel obstruction. Forty-two Wistar albino rats were divided into four groups: I, control (n = 5); II, sham laparotomy (n = 5); III, simple obstruction (n = 16); and IV, strangulation groups (n = 16). Activity levels of total Hex and its fractions (Hex A and B) were assayed in serum samples obtained from rats after 3 and 8 hr. Samples of small bowel were also evaluated histologically. Histological evaluation of bowel sections obtained from the strangulation group after 8 hr, revealed transmural hemorrhagic infarction in all animals with a mean +/- SD total Hex activity of 978.25 +/- 150 nmol/hr/ml, which was significantly higher than that in the other groups (P < 0.001). Although sections of bowel from the strangulation group after 3 hr showed severe ischemic injury, the activities of total Hex, Hex A, and Hex B were not different from those of the control, sham, and simple obstruction groups. Histological examination of these groups did not show any sign of ischemia. Total Hex, Hex A, and Hex B activities in the strangulation group were all significantly greater than the activities seen in the simple obstruction group (P < 0.001, for all). In conclusion, increased serum hex levels indicate irreversible transmural infarction only in the late period of strangulation in the closed loop small bowel obstruction model. It seems unuseful for detecting reversible and/or irreversible ischemia in the early period of strangulation.

Assessing the severity of the small inframe deletion mutation in the alpha-subunit of beta-hexosaminidase A found in the Turkish population by reproducing it in the more stable beta-subunit.

GM(2) gangliosidoses are a group of panethnic lysosomal storage diseases in which GM(2) ganglioside accumulates in the lysosome due to a defect in one of three genes, two of which encode the alpha- or beta-subunits of beta- N -acetylhexosaminidase (Hex) A. A small inframe deletion mutation in the catalytic domain of the alpha-subunit of Hex has been found in five Turkish patients with infantile Tay-Sachs disease. To date it has not been detected in other populations and is the only mutation to be found in exon 10. It results in detectable levels of inactive alpha-protein in its precursor form. Because the alpha- and beta-subunits share 60% sequence identity, the Hex A and Hex B genes are believed to have arisen from a common ancestral gene. Thus the subunits must share very similar three-dimensional structures with conserved functional domains. Hex B, the beta-subunit homodimer is more stable than the heterodimeric Hex A, and much more stable than Hex S, the alpha homodimer. Thus, mutations that completely destabilize the alpha-subunit can often be partially rescued if expressed in the aligned positions in the beta-subunit. To better understand the severity of the Turkish HEXA mutation, we reproduced the 12 bp deletion mutation (1267-1278) in the beta-subunit cDNA. Western blot analysis of permanently transfected CHO cells expressing the mutant detected only the pro-form of the beta-subunit coupled with a total lack of detectable Hex B activity. These data indicate that the deletion of the four amino acids severely affects the folding of even the more stable beta-subunit, causing its retention in the endoplasmic reticulum and ultimate degradation.

Biochemical and molecular characterization of mutant hexosaminidase A in a Turkish family.

BACKGROUND: Tay-Sachs disease is a form of monosialoganglioside triaose (GM2) gangliosidosis that results from the mutations in the alpha-subunit gene of hexosaminidase A. In the B1 variant, the active site of the alpha-subunit of the enzyme is thought to be affected. In the present study, a patient who had previously been diagnosed as a B1 variant is further analyzed. The patient's parents and brother were also analyzed. METHODS: Single-stranded conformational polymorphism (SSCP) and DNA sequencing analysis were conducted in all cases. In addition, hexosaminidase A (Hex A) was isolated from leukocyte homogenates of the patient's parents and brother using DE 52 ion-exchange chromatography, and thermostability analyses of the isolated enzymes were performed. RESULTS: Hexosaminidase A of the parents was found to be more thermostable than normal Hex A. DNA sequencing analysis revealed a 12-bp deletion mutation in exon 10 of the Hex A gene. The patient was a homozygote and the parents were heterozygotes for the mutation, which could also be observed at the DNA double strands by SSCP analysis. These deleted bases are located within the catalytic domain of the alpha-subunit. CONCLUSIONS: The 12-bp deletion mutation in exon 10 of Hex A is responsible for the increased thermostability of the enzyme. Considering this mutation has previously been found in a Turkish Tay-Sachs patient, the patient in the present study may have another mutation on the Hex B gene that causes decreased thermostability of the enzyme. Thermal inactivation assay may not be sufficient for a correct diagnosis in such unusual cases.

Propofol anaesthesia and metabolic acidosis in children.

BACKGROUND: We aimed to investigate the effect of propofol infusion anaesthesia on acid-base status and liver and myocardial enzyme levels of children during short-term anaesthesia. METHODS: Thirty-six children, aged 3-12 years, were randomized into two groups. In group P (n = 18), induction and maintenance were performed with propofol, 3 mg x kg-1 and 20, 15 and 10 mg x kg-1 x h-1, respectively. In group H (n = 18) following induction with 5 mg x kg-1 thiopenthal, anaesthesia was maintained with 2-3% halothane. Blood samples were obtained following anaesthesia induction and 30, 60 and 120 min after discontinuation of anaesthesia. RESULTS: There was no difference in lactate dehydrogenase, myocardial creatininephosphokinase, aspartate aminotransferase, alanine aminotransferase and cholesterol levels between and within the groups. All postoperative triglyceride levels were higher and pH levels were lower in group P than group H (P < 0.05) and there was no difference within the groups. CONCLUSIONS: In these healthy patients, short-term use of propofol did not result in significant acidaemia, nor alterations in hepatic or myocardial enzyme levels.

Incision and venous patch graft in the surgical treatment of penile curvature in Peyronie's disease.

OBJECTIVES: To assess the efficacy of incision and venous patch grafting method in the surgical treatment of the curvature in Peyronie's disease. METHODS: Fifty-eight patients with Peyronie's disease underwent incision of the tunica albuginea with Peyronie's plaque(s) and venous patch grafting between 1994 and 1999. Segment(s) of lower saphenous vein in 48, deep dorsal vein in 7, and upper saphenous veins were used in 3 cases as venous patch(es). Assessment of the potency status, curvature, and vascular structure were performed pre-operatively with detailed history, counselling, autophotography, and color Doppler ultrasonography. Realistic expectations from the surgery was discussed with the patients in advance. Postoperative evaluation was performed at least twice, in the 6th week and the 3rd month. The third evaluation was done in 12-36 months by telephone. RESULTS: Fifty of the patients (86%) achieved straight erections after the surgery. Five patients (9%) had improvement in their penile curvature that enabled them to perform sexual intercourse easily. In 3 of our patient (5%) recurrence of the curvature was observed. Penile shortening of 0.5-1.5 cm was observed in 13 of the cases (22.4%). Fifty-four cases (93%) reported no change in their quality of erections. CONCLUSION: Incision of the tunica albuginea and venous patch grafting technique is a very satisfactory surgical method in the treatment of the curvature in Peyronie's disease.

Apoptosis in the erectile tissues of diabetic and healthy rats.

OBJECTIVE: To compare the frequency of apoptosis in the erectile tissue of chronic diabetic and healthy rats. MATERIALS AND METHODS: Fourteen chronic diabetic and 10 healthy Sprague-Dawley rats were killed, their penises harvested and stored at -70 degrees C until staining and flow cytometric analysis for apoptosis. A cell suspension was obtained from the penile tissue by scraping the inside of the cavernosum with a scalpel and filtering through a mesh. Samples of the cell suspension (0.5 x 106 cells) were stained with Annexin V (an indicator of apoptosis) and propidium iodide (PI, which stains dead cells), incubated for 15 min at room temperature and analysed by flow cytometry. The DNA content was also analysed in each sample. RESULTS: In normal erectile tissue, a mean of 6.2% of cells were stained with Annexin V, while only 2.7% were stained with PI; DNA content analyses showed 7.5% were hypodiploid cells. In diabetic rats 19.5% of cells were stained with Annexin V and 5.2% with PI; 22.9% of cells were hypodiploid. CONCLUSION: The ratio of apoptotic cells in the erectile tissues of diabetic rats was significantly greater than in normal rats. The high rate of apoptosis in diabetic rats may play a role in the pathophysiology of erectile dysfunction.

Retrospective analysis of medicolegal cases and evaluation for erectile function.

Erectile function (EF) is an important question in lawsuits for divorce, rape, and damages. In this study, a method to evaluate medicolegal cases is defined, and the characteristics of the 265 cases screened for EF between 1989 and 1997 were analyzed. Interview, physical examination, psychometric evaluation, nocturnal penile tumescence, serum hormone levels and blood chemistry, intracavernosal drug injection, penile Doppler ultrasonography, and pharmacocavernosometry and pharmacocavernosography tests were used for diagnosis. The tests performed were selected according to the age of the subject. Of the 265 cases 128 (48.3%) were for divorce, 116 (43.7%) were for rape, and 21 (8%) were for indemnity relating to lawsuits for damages. In only 7 cases (2.7%) was the defendant <15 years of age. Organic pathology for erectile dysfunction (ED) was present in 22% of lawsuits for divorce, 40.5% of lawsuits for rape, and 33.4% of lawsuits for damages. Three men in cases of divorce and 2 men after genital trauma due to traffic accident suffered psychological ED. This study indicates that lawyers may abuse the assertion of ED in lawsuits for divorce and rape. In 128 divorce cases the defendant was accused of being impotent, but evaluation proved that 75.8% had normal EF. In lawsuits for rape, 59.5% of defendants had normal EF although the lawyers of the rapist claimed their clients were impotent. The investigation, interpretation, and characteristics of medicolegal cases may differ in countries with different cultures.

Amplification of the c-myc oncogene in non-small cell lung cancer.

Fresh non-small cell lung carcinoma surgical specimens were taken from 17 patients and 3 controls and screened for genetic abnormalities of the c-myc oncogene. Southern blot hybridization analysis demonstrated two- to fivefold amplification of the c-myc gene in 10 cases, i.e., 7 of 13 epidermoid lung carcinomas, 2 of 3 adenocarcinomas and 1 of 1 osteogenic sarcoma metastatic to the lung. Two- to fivefold amplification was observed in tissues from stage III and IV epidermoid carcinomas and adenocarcinomas of the lung. A correlation between cancer stage and c-myc gene amplification was found.

Evaluation of renal function in low-dose cyclosporine-treated patients using technetium-99m diaminocyclohexane: a cationic tubular excretion agent.

Technetium-99m diaminocyclohexane (DACH) is a new tubular agent excreted via a cationic transport mechanism, like cyclosporine-A (CsA). It is expected that 99mTc-DACH will permit effective assessment of tubular function in CsA-treated patients. To establish the pharmacokinetic characteristics of 99mTc-DACH and to ascertain whether this new agent is useful in CsA-treated patients, 11 healthy volunteers and 15 CsA-treated patients underwent renal imaging and clearance studies using 99mTc-DACH and chromium-51 ethylene diamine tetra-acetic acid (EDTA). 99mTc-DACH yielded satisfactory dynamic renal images in all participants. The mean plasma clearance of 99mTc-DACH was significantly greater than that of 51Cr-EDTA in volunteers (109.4¿19.7 ml/min versus 86.6 +/- 13.7 ml/min, P<0.05). However, the urinary excretion of 99mTc-DACH at 90 min was significantly lower than that of 51Cr-EDTA (46.1% +/- 9.3% versus 53.1% +/- 8.6%, P<0.05), most probably due to its partial parenchymal retention. The elimination half-life of 99mTc-DACH was significantly increased in CsA-treated patients in comparison to volunteers, and consequently the plasma clearance values were significantly suppressed in these patients, in contrast to 51Cr-EDTA and endogenous creatinine clearance values. In conclusion, our findings indicate that 99mTc-DACH, as a sensitive marker of cationic tubular function, could be used to monitor renal haemodynamics in patients receiving CsA treatment.

At least six different mutations in HEXA gene cause Tay-Sachs disease among the Turkish population.

Twenty-five Turkish infants with Tay-Sachs disease (TSD) have been diagnosed in the past 8 years. All are from consanguineous, nonrelated families. The present study deals with the molecular basis of six Turkish TSD patients from five unrelated families in which the parents were first cousins. The five mutations identified in this study were INS-5 G-->A, R393X, R137X, 12-bp deletion in exon 10, and G454D. The first three were reported in earlier studies, two in Turkish TSD infants and one in a French TSD infant.

Comparison of three different primer pairs for the detection of Mycobacterium tuberculosis by polymerase chain reaction in paraffin-embedded tissues.

SETTING: More than five different primer pairs have been used for the detection of Mycobacterium tuberculosis deoxyribonucleic acid (DNA) with the polymerase chain reaction (PCR). OBJECTIVE: The sensitivity and specificity of PCR were evaluated using three different primer pairs in the detection of M. tuberculosis in paraffin-embedded tissues. DESIGN: Thirty-eight tissue specimens from 23 patients were studied. Eighteen samples were obtained from 10 tuberculosis patients, and 20 samples obtained from 13 patients with other diseases were used as negative controls. DNA extracted from paraffin-embedded tissues was used directly for PCR amplification using primers IS1 and IS2 to amplify a 123 base pair (bp) region of IS6110, sjMT3 and sjMTr2 to amplify a 281 bp region of protein antigen b, and INS1 and INS2 to amplify a 245 bp region of IS986. Each amplification was performed double-blinded and repeated three times including positive and negative control samples. RESULTS: IS1 and IS2 gave a positive result in each of the double samples obtained from eight tuberculosis patients and in the single samples obtained in the two others, sjMT3 and sjMTr2 detected 13 of the 18 tuberculosis samples, and INS1 and INS2 detected only three of the 18. CONCLUSION: These results highlight the importance of selecting appropriate primers to obtain high sensitivity in detecting M. tuberculosis in paraffin-embedded tissues by PCR.

Repetition of color Doppler ultrasonography: is it necessary?

The aim of the study was to determine whether any difference would occur in peak systolic velocity (PSV) and end diastolic velocity (EDV) measurements of color Doppler ultrasonography (CDU) between proximal and distal segments of the cavernous arteries obtained at different times. Twenty-six cases have undergone CDU three times in weekly intervals. PSV and EDV measurements of cavernous arteries were obtained both proximally and distally. The results have shown that statistically there was no difference between each measurement obtained on either sides at three different tests. (ANOVA PSV F(2-50) = 0.63, EDV F(2-50) = 0.81). Four of the 26 cases had different PSV results and six cases had different EDV results in three CDU tests. There was a statistical difference in measurements between proximal and distal segments of the cavernous arteries. (t-test t = 2.53, P = 0.015) In conclusion, repetition of CDU would not be necessary in majority of the cases. However investigators should always be aware and cautious about falsely abnormal results of CDU. Proximal segments of the cavernous arteries should be the site to obtain true CDU measurements.