Age-related changes in ac-impedance spectroscopy studies of normal human dentine: further investigations.

One of the age-related changes occurring in dentine structure is the formation of peritubular dentine on the inner walls of dentinal tubules leading to complete closure of tubules. Ac-impedance is safe, fast and non-invasive technique. In the last decade, the popularity of the technique has increased in dental research. Several investigators have used the technique to detect tooth cracks and caries. The results of in vitro studies showed that ac-impedance technique was more advanced for caries detection than visual and radiographic methods. However, other studies demonstrated that the accuracy of impedance measurements can be affected by many factors such as remineralization after tooth eruption. A study has been published on effect of age on impedance measurements by the authors for two age groups by employing ac-impedance spectroscopy. Therefore, the aim of this study was to demonstrate the importance of this technique by conducting further investigations on dentine samples of wider age groups. Dentine samples were prepared from extracted sound third molars of known patient age. The ac-impedance measurements were carried out over a wide range of frequency. After performing all electrical measurements, dentine samples were examined under SEM to correlate the electrical measurements with their structure. Impedance measurements showed that there were differences in impedance between young and old dentine. One-way ANOVA of the means of resistance and capacitance for all age groups (20, 25, 30, 40 and 50 years old dentine) revealed a significant difference (ANOVA, P < 0.0001) as a function of age. Applying Tukey's post hoc test, to the same data showed that this difference was due to the 50 years old dentine for resistance and was due to the 40 and 50 years old dentine for capacitance which were statistically different to all other groups. SEM investigation of dentine samples showed that young dentine is characterized by open dentinal tubules distributed all over the sample while in old dentine most dentinal tubules were occluded by peritubular dentine. It is believed that this peritubular deposition is responsible for differences in impedance measurements. In spite of increasing use of electrical techniques to understand electrical properties of teeth, it is clear from this study that local structural variations have a marked influence.

Investigations on silicon/amorphous-carbon and silicon/nanocrystalline palladium/ amorphous-carbon interfaces.

Our previous work revealed that significant enhancement in sp3-carbon content of amorphous carbon films could be achieved when grown on nanocrystalline palladium interlayer as compared to those grown on bare silicon substrates. To find out why, the nature of interface formed in both the cases has been investigated using Electron Probe Micro Analysis (EPMA) technique. It has been found that a reactive interface in the form of silicon carbide and/silicon oxy-carbide is formed at the interface of silicon/amorphous-carbon films, while palladium remains primarily in its native form at the interface of nanocrystalline palladium/amorphous-carbon films. However, there can be traces of dissolved oxygen within the metallic layer as well. The study has been corroborated further from X-ray photoelectron spectroscopic studies.

A cross section of autosomal recessive limb-girdle muscular dystrophies in 38 families.

Limb-girdle muscular dystrophies constitute a broad range of clinical and genetic entities. We have evaluated 38 autosomal recessive limb-girdle muscular dystrophy (LGMD2) families by linkage analysis for the known loci of LGMD2A-F and protein studies using immunofluorescence and western blotting of the sarcoglycan complex. One index case in each family was investigated thoroughly. The age of onset and the current ages were between 11/2 and 15 years and 6 and 36 years, respectively. The classification of families was as follows: calpainopathy 7, dysferlinopathy 3, alpha sarcoglycan deficiency 2, beta sarcoglycan deficiency 7, gamma sarcoglycan deficiency 5, delta sarcoglycan deficiency 1, and merosinopathy 2. There were two families showing an Emery-Dreifuss phenotype and nine showing no linkage to the LGMD2A-F loci, and they had preserved sarcoglycans. gamma sarcoglycan deficiency seems to be the most severe group as a whole, whereas dysferlinopathy is the mildest. Interfamilial variation was not uncommon. Cardiomyopathy was not present in any of the families. In sarcoglycan deficiencies, sarcoglycans other than the primary ones may also be considerably reduced; however, this may not be reflected in the phenotype. Many cases of primary gamma sarcoglycan deficiency showed normal or only mildly abnormal delta sarcoglycan staining.

Myogenesis within the human gubernaculum: histological and immunohistochemical evaluation.

BACKGROUND: The presence of varying amounts of smooth muscle (SM) in the patent processus vaginalis suggests that SM plays a role in the descent of the testis. Myogenesis within the gubernaculum (representing primitive mesenchymal tissue) has been evaluated. MATERIALS AND METHODS: Bilateral gubernacula of ten male and five female fetuses were obtained. Sections were stained with hematoxylin-eosin, van Gieson and Gomori trichrome. Expressions of human muscle actin, desmin, vimentin, alpha-smooth muscle actin, human myosin, fast myosin, slow myosin, and Myo-D were determined through immunohistochemistry. The structural alterations and expressions according to the fetal ages were determined within the gubernacula of both sexes. RESULTS: Gubernacula revealed striated muscle at twelve weeks of age. Despite expression of actin and desmin, those muscles did not express Myo-D. Actin and desmin expressing striated muscles ceased to exist until 22 weeks of age. Both vascular SM and cremaster muscle (CM) expressed Myo-D during the 22nd and 23rd weeks. CM additionally expressed alpha-smooth muscle actin. Detection of myofibroblasts in the 22nd week was followed by appearance of the SM in the 27th week in the gubernacula of male fetuses. The same alterations were encountered among the female fetuses at later time points. CONCLUSION: Both smooth muscle and CM develop within the gubernaculum. CM may have transdifferentiated from the vascular SM. If the gubernaculum represents primitive mesenchymal tissue, it ceases to exist after the development of muscles.

Management of bilateral Wilms tumor over three decades: The perspective of a single center.

INTRODUCTION: Outcomes of Wilms tumor improved in last 50 years and excellent survival rates can be achieved especially in case of non-metastatic disease and favorable histology. Nevertheless, bilateral cases still stand as a therapeutic challenge. Prognosis of bilateral Wilms tumor (BWT) is not as good as the unilateral tumors of similar stage and histology in terms of survival and renal function. OBJECTIVE: Management of BWT is constantly evolving and still stands as a therapeutic challenge. This study is designed to review and share our experiences on this topic from a surgical standpoint. STUDY DESIGN: The records of patients treated in our clinic between 1980 and 2013 according to Turkish Pediatric Group of Oncology protocol were analyzed retrospectively and clinical data, surgical details, pathology results, long term outcomes were analyzed. RESULTS: Thirteen girls and 7 boys with a mean age of 2,5 years were treated. There were 2 patients with Wilms tumor-Aniridia-Growth Retardation complex and one with isolated hemihypertrophy. Metastasis were detected in lungs of 4 patients; liver of 2 and in the cranium of one. All patients except one with the presumptive diagnosis of unilateral Wilms tumor were given preoperative chemotherapy. To sum up; 19 nephroureterectomies, 8 partial nephrectomies and 13 enucleations were performed to 36 kidneys without any major early or late postoperative complications. Pathologic results revealed positive surgical margins in 2 lesions with enucleation and in 2 with partial nephrectomies and anaplasia in 4 patients. Two patients were not operated due to parental disapproval. Two patients had the need of dialysis; one was anephric and the others' renal functions recovered over a year. Seven patients received radiotherapy for pulmonary metastasis, positive surgical margins or local recurrences. Overall, 13 patients survived and 7 died due to metastasis, recurrences, and complication of dialysis and refusal of surgical treatment. Survival among all patients was 65% and 72.2% among operated ones. Of the 7 patients with the partial nephrectomy, 2 died and 5 survived. Among enucleation group, 8 out of 10 survived and 2 died. Survival was slightly higher among enucleation group (80% vs 71.4%). Median time of follow-up for survivors of disease is 5.8 years (min: 6 months and max: 14 years). DISCUSSION: Outcomes of BWT management have changed dramatically during the last few decades from only survival, to a long life expectancy without the need of renal replacement therapy owing to improvements in treatment options. We argue that positive surgical margins do not necessarily lead to local recurrence. For this reason it may be wiser to favor on more nephron sparing surgery than to achieve negative surgical margins. Adjuvant chemotherapy and radiotherapy may be adequate to prevent local recurrence. Also, survival did not differ significantly between different ways of nephron sparing surgeries, so it may be wiser to choose enucleation over partial nephrectomy which preserves more nephrons. Nephron-sparing surgery should have utmost importance despite the risk of positive margins. On the other hand, there is not enough data to interpret if positive surgical margins have role on distant metastases or not. Presence of metastasis and recurrence seems to be an important determinant of prognosis given the fact that none of the survivors had any metastasis or recurrence. CONCLUSION: Nephron preservation should be the aim while taking positive surgical margin risk on nephron sparing surgery side relying on postoperative chemotherapy and carefully planned radiotherapy to avoid recurrence. However, there is significant diversity on the management BWT in different centers and a certain validated guideline or protocol to provide the optimal treatment is still lacking.

Merosin-deficient congenital muscular dystrophy with severe mental retardation and normal cranial MRI: a report of two siblings.

The evidence of severe structural brain abnormalities in association with severe mental retardation is characteristic in congenital muscular dystrophy (CMD) forms other than the 'classical' form. However, it seems that the nosology of CMD is not complete yet, as we have clinical, immunohistochemical and genetic data suggesting that there are other unclassified forms. Here we report two CMD siblings from a consanguineous family with partial merosin-deficiency in muscle biopsies, severe mental retardation and normal MRI of the brain. The disease was not linked to the LAMA2 gene (6q22-23) or to Fukuyama congenital muscular dystrophy (FCMD) (9q31-33). To our knowledge, such an association may constitute a new entity within the broad clinical spectrum of CMD.

Intestinal lymphangiectasia in a patient with Zellweger cerebrohepatorenal syndrome.

Zellweger cerebrohepatorenal syndrome (ZWCHRS) is an autosomal-recessive disease, characterized by the absence or profound deficiency of peroxisomes. We report a case of ZWCHRS with intestinal lymphangiectasia, observed as an autopsy finding. This combination is previously unreported.

Common deletion of mitochondrial DNA in a 5-year-old girl with failure to thrive, ptosis, ophthalmoplegia and ragged-red fibers.

A girl aged 4 years and 10 months presented with failure to thrive, ptosis, ragged-red fibers and the common 4.9 kb mitochondrial DNA deletion. She had elevated serum lactic and pyruvic acids. The onset was at around 18 months. There were no signs of retinitis, and abnormal renal, liver or pancreatic functions. She later developed mild ophthalmoplegia at 6 years of age. Additional features of chronic progressive external ophthalmoplegia (CPEO) or Kearns-Sayre syndrome (KSS) are the conditions that should be watched and investigated in the long-term follow-up of this girl.

Congenital muscular dystrophy (non-Fukuyama type) in Turkey: a clinical and pathological evaluation.

Congenital muscular dystrophy (CMD) is a heterogenous group of disorders. In the majority of cases the intelligence is preserved, which comprises the classic "occidental" (type 1) form. This type appears to be prevalent in the west. We report a five-case series in Turkey, confirming its geographical distribution.