Identification of corneal and intra-epidermal axonal swellings in amyotrophic lateral sclerosis.

INTRODUCTION/AIMS: In patients with amyotrophic lateral sclerosis (ALS), axonal spheroids in motor axons have been identified in post-mortem studies. In this study, axonal spheroids and swellings on C-fibers of ALS patients were investigated using corneal confocal microscopy (CCM) and skin biopsy, respectively. METHODS: Thirty-one ALS patients and 20 healthy subjects were evaluated with CCM to assess corneal nerve-fiber length (CNFL), -fiber density (CNFD), -branch density (CNBD), dendritic cell (DC) density, and axonal spheroids originating from C-fibers (>100 µm2 ). In addition, intraepidermal nerve fiber density (IENFD) and axonal swellings (>1.5 µm) were assessed in skin biopsies obtained from the arms and legs of 22 patients and 17 controls. RESULTS: In ALS patients, IENFD, CNFD, CNFL, and CNBD were not different from controls. The density of DCs and the number of patients with increased DC density were higher in ALS patients than controls (p = .0005 and p = .008). The number of patients with axonal spheroids was higher than controls (p = .03). DISCUSSION: Evaluation of DCs and axonal bulbs in C-fibers of ALS patients could provide insights into pathophysiology or potentially serve as biomarkers in ALS.

Radiotherapy-induced alterations in vitreous humor: A new potential critical structure.

Vitreous humor (VH) is not considered as a critical structure in the radiotherapy planning process. In the present study, an experimental animal model was performed to examine the effects of radiotherapy on VH. The right eyes of twelve New Zealand rabbits were irradiated to 60 Gy in 3 fractions in accordance with the scheme used in the treatment of uveal melanoma in our clinic, and contralateral (left) eyes were considered as control. Weekly ophthalmologic examination was performed after irradiation, for three months. At the end of the third month, enucleation and vitreous collection were conducted. The vitreous samples were subjected to metabolomic analyses, ELISA analyses, viscosity measurements, and electron microscopic examination. In control and experimental vitreous samples, 275 different metabolites were identified, and 34 were found to differ significantly between groups. In multivariate analyzes, a clear distinction was observed between control and irradiated vitreous samples. Pathway analysis revealed that nine pathways were affected, and these pathways were mainly related to amino acid metabolism. A significant decrease was observed in the expressions of type II, V, and XI collagens in protein level in the ELISA. There was a non-significant decrease in type IX collagen and viscosity. Electron microscopic examination revealed disrupted collagen fibrillar ultra-structure and dispersed collagen fragments in the experimental vitreous. An intact vitreous is essential for a healthy eye. In this study, we observed that radiation causes changes in the vitreous that may have long-term consequences.

Melatonin Improves Reduced Activities of Membrane ATPases and Preserves Ultrastructure of Gray and White Matter in the Rat Brain Ischemia/Reperfusion Model.

Ischemia/reperfusion (I/R) is among the most frequent neurological problems and early intervention to limit the damage is crucial in decreasing mortality and morbidity. Based on reports regarding beneficial effects of melatonin, we investigated its impact on Na+-K+/Mg2+ ATPase and Ca2+/Mg2+ ATPase activities and ultrastructure of gray and white matter in the rat forebrain I/R model. Adult Wistar-albino rats (n = 78), were randomized into control, ischemia (I), ischemia/reperfusion (I/R), low (I/R + melatonin 400 µg/kg), moderate (I/R + melatonin 1200 µg/kg), and high (I/R + melatonin 2400 µg/kg) dose melatonin. Two-vessel occlusion combined with hypotension (15 min) induced ischemia and reperfusion (75 min) achieved by blood reinfusion were performed. Activities of the membrane-bound enzyme, brain malondialdehyde levels, and brain matter ultrastructure were examined in frontoparietal cortices. Melatonin lowered production of malondialdehyde in a dose-dependently. The enzyme activities attenuated under I and I/R, improved with melatonin treatment. I and I/R severely disturbed gray and white matter morphology. Melatonin, in all applied doses, decreased ultrastructural damages in both gray and white matter. Favorable effects of melatonin can be attributed to its antioxidant properties suggesting that it could be a promising neuroprotective agent against I/R injury being effective both for gray and white matter due to favorable biological properties.

PREVENTION OF RADIATION-INDUCED RETINOPATHY WITH AMIFOSTINE IN WISTAR ALBINO RATS.

PURPOSE: To evaluate the radioprotective efficacy of amifostine on irradiated mature rat retina. METHODS: A total of 108 Wistar albino rats were categorized into 3 groups, namely, apoptosis (n = 48), acute effects (n = 40), and late changes in retinal cell layers (n = 20). Each group was further subcategorized into 4 arms: control, amifostine (A), radiotherapy + placebo (RT), and RT + A arms, respectively. Intraperitoneal amifostine (260 mg/kg) was administrated to A and RT + A arms 30 minutes before irradiation. Control and A groups were sham-irradiated, whereas a single dose of 20 Gy whole-cranium irradiation was delivered to RT and RT + A arms. Apoptosis was assessed in 8, 12, and 18 hours after irradiation. Electron microscope was used 2 weeks after irradiation for evaluation and scoring of early morphologic changes in retina. Late effects were assessed and scored accordingly by using both the electron and the light microscope on Week 10. RESULTS: At acute phase, although no notable change was seen in 8 hours, significant increase in apoptosis was detected in 12 hours in RT arm (P = 0.029). Comparative analyses between the groups in 3 different time points displayed a higher apoptotic rate in RT group than the RT + A group (P = 0.008). Similarly, comparisons between groups for late effects on the basis of electron microscopic findings revealed lower scores in the RT + A than the RT arm (P < 0.001). CONCLUSION: This study suggested a potential radioprotective role for amifostine on mature rat retina by reducing radiation-induced apoptosis in retinal cells. These results form a basis for such preclinical investigations and call for future clinical studies.

Histopathological changes in nasal mucosa with nasal septum deviation.

Histopathological changes in septal and nasal mucosa of patients with nasal septum deviation are not well known. Biopsies of septal and lateral nasal mucosae from both sides of nose were obtained from 20 patients undergoing septoplasty and control group of 10 patients undergoing head and neck surgery. Histopathological changes including lymphocytic infiltration and squamous metaplasia were compared. This study determined significantly higher rate of squamous metaplasia and lymphocytic infiltration in septal mucosa opposite the deviation compared to control group. Furthermore, there was a significantly higher rate of lymphocytic infiltration in the lateral nasal wall mucosa opposite the deviation when compared to control group. Increased lymphocytic infiltration and squamous metaplasia are observed on both sides of nasal mucosa; however, they are more severe on the side opposite the deviation. Septal deviation predisposes to chronic mucosal inflammation and squamous metaplasia, both of which may render patients susceptible to chronic rhinosinusitis.

Transmastoid exposure of the labyrinthine segment of the facial nerve: an anatomical study.

INTRODUCTION: Compression of the labyrinthine segment of the facial nerve by edema has been considered as an important pathology in the majority of the cases of idiopathic facial nerve paralysis. Hence, it is suggested that total decompression of the facial nerve should also include the labyrinthine segment by a middle fossa approach. However, the middle fossa approach requires craniotomy and temporal lobe retraction, which increases the morbidity. The labyrinthine segment of the facial nerve can also be reached through mastoidectomy. However, many ear surgeons are not familiar with this approach due to the lack of anatomical data on this surgical area. OBJECTIVE: To study the anatomical limitations of decompression of the labyrinthine segment via transmastoid approach. METHODS: Complete mastoidectomy was performed in six adult cadavers heads. Dissection was extended in the zygomatic root and posterior bony wall of the external auditory canal to visualize the incudomallear joint completely. The bone between tympanic segment, lateral and superior semicircular canal's ampullas and middle fossa dural plate was removed. Fine dissection was carried out over tympanic segment of the facial nerve in an anterosuperomedial direction the labyrinthine segment was reached. RESULTS: All the mastoids were well pneumatized. Distances between the labyrinthine segment and middle fossa dura, and between the labyrinthine segment and superior semicircular canal, were 2.5 and 4.5 mm on average, respectively. In addition, distances between the middle fossa dura and dome of the lateral semicircular canal, and between the middle fossa dura and tympanic segment were 4.6 mm and 4.3 mm on average, respectively. CONCLUSION: It is possible to expose the labyrinthine segment of the facial nerve through mastoidectomy by dissecting the bone in the area between the tympanic segment of the facial nerve, middle fossa dural plate and ampullary ends of the lateral and superior semicircular canals.

Evaluation of the Hematological and Serum Biochemistry Parameters in the Pre-Symptomatic and Symptomatic Stages of ALS Disease to Support Early Diagnosis and Prognosis.

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. Since there are no pathognomonic tests for ALS prognoses; clinical diagnoses of the disease take time and are usually difficult. Prognostic biomarkers are urgently needed for rapid and effective ALS prognoses. Male albino rats were divided into ten groups based on age: 0 (40-45 days old), A (70-75 days old), B (90-95 days old), C (110-115 days old), and D (130-135 days old). Each group was divided into two subgroups according to its mutation status: wild type (SOD1WT) or mutated (SOD1G93A). Serum biochemistry and hematological parameters were measured in 90 rats to evaluate possible biomarkers for faster ALS diagnoses and prognoses. Weight loss, cholesterol, creatinine, glucose, total bilirubin (TBIL), blood urine nitrogen (BUN), c-peptide, glucagon, PYY, white blood cell (WBC), lymphocyte (LYM), monocyte (MID), granulocyte (GRAN), red cell distribution width with standard deviation (RDW-SD), red cell distribution width with the coefficient of variation (RDW-CV), platelet (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and procalcitonin (PCT) levels were changed in the SOD1G93A rats compared to the SOD1WT rats independently from aging. For the first time in the literature, we showed promising hematological and serum biochemistry parameters in the pre-symptomatic and symptomatic stages of ALS by eliminating the effects of aging. Our results can be used for early diagnoses and prognoses of ALS, improving the quality of life and survival time of ALS patients.

Stereological and electrophysiological evaluation of autonomic involvement in amyotrophic lateral sclerosis.

OBJECTIVE: Previous studies have identified autonomic dysfunction in amyotrophic lateral sclerosis (ALS) using mostly neurophysiological techniques. In this study, stereological evaluation of autonomic fibers and sweat glands has been performed to identify structural evidence of autonomic denervation in patients with ALS. METHODS: In this study, 29 ALS patients were compared to 29 controls using COMPASS-31 questionnaire, sympathetic skin response (SSR), and heart rate variability (HRV) at rest. From the same cohorts, 20 ALS patients and 15 controls were further evaluated using staining of autonomic nerve fibers and sweat glands in skin biopsies. SSR and resting HRV were repeated in the ALS patient cohort one year later. RESULTS: COMPASS-31 total score, gastrointestinal- and urinary-sub scores were higher in ALS patients than controls (P = 0.004, P = 0.005, and P = 0.049, respectively). In the ALS patient cohort, SSR amplitudes in hands and feet were lower than in controls (P<0.0001 and P = 0.0009, respectively), but there was no difference in resting HRV (P>0.05). While there was no change in nerve fibers innervating sweat glands, their density was lower in ALS patients than controls, and semi-quantitative analysis also showed structural damage (P = 0.02 and P = 0.001, respectively). SSR and resting HRV of ALS patients remained stable during the one-year follow-up period (P>0.05). DISCUSSION: Supporting abnormal neurophysiological tests, stereological analysis revealed direct evidence of autonomic denervation in ALS patients. However, the degenerative process in autonomic nerve fibers is relatively slow, compared to the rate of motor neuron degeneration in this condition.

Comparison of the Morphologic and Mechanical Features of Human Cranial Dura and Other Graft Materials Used for Duraplasty.

OBJECTIVE: This study aimed to compare the thickness and mechanical properties of the frontal; parietal; temporal; occipital human dura; autogenous grafts (facia lata, temporal fascia, galea aponeurotica); and artificial dura. METHODS: Sagittal and transverse dura samples were obtained from standard regions of the cranial dura from 30 autopsies for histologic and mechanical property measurements. Identical measurements were made for the autogenous grafts artificial dura, and the results were statistically analyzed. RESULTS: The thickness of the temporal (0.35 ± 0.11 mm), parietal (0.44 ± 0.13 mm), frontal (0.38 ± 0.12 mm), and occipital (0.46 ± 0.18 mm) dura showed regional variations. The parietal and occipital dura were significantly thicker than the temporal dura. The occipital dura was considerably thicker than the frontal dura. The frontal and temporal dura of males were significantly thicker than females. The sagittal maximum tensile force measurements were significantly greater than transverse, for the frontal, temporal, and occipital dura. The stiffness measurements in sagittal direction were greater than the measurements in transverse direction for the frontal dura. The mechanical properties and thickness of the autogenous and artificial dura were not similar to the human dura. CONCLUSIONS: The thickness and mechanical properties of the regional cranial dura should be taken into consideration for a better cure and fewer complications. The mechanical properties of sagittal and transverse dura should be kept in mind for the preference of dura material. The present study's data can pave the way to produce artificial regional dura by mimicking the thickness and mechanical properties of the human dura.

Anatomy of the azygos vein examined by computerized tomography imaging.

OBJECTIVE: To examine the anatomy of the azygos vein AV using different parameters. Therefore, the diameter of the AV at its opening into the superior vena cava, the opening level of the AV into the superior vena cava, and the position of the AV, with respect to the vertebral column and carina, were examined by CT. METHODS: Chest CTs of 103 cases (42 female and 61 male) were reviewed at the Department of Radiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey between July 2004 and February 2005. The CT examinations were performed with a Philips AU E1 spiral CT (Rotterdam, Netherlands) with the following parameters: 120 Hv; 200 mAs; slice thickness: 7 mm; pitch: 1; reconstruction index: 7 mm. The results were statistically analyzed. RESULTS: The diameter of the AV at the opening into the superior vena cava ranged between 4.3 mm and 16 mm. The AV was in the midline in 41 cases. The arching and opening level of the AV was at the fifth thoracic vertebra in most cases. The opening level was most often at the same level as the carina. Hemiazygos veins were detected in 90 patients. CONCLUSION: The parameters measured in this study may be useful in surgical procedures of the mediastinum and during the interpretation of chest radiographs.

Transmastoid exposure of the labyrinthine segment of the facial nerve: an anatomical study,

Abstract Introduction: Compression of the labyrinthine segment of the facial nerve by edema has been considered as an important pathology in the majority of the cases of idiopathic facial nerve paralysis. Hence, it is suggested that total decompression of the facial nerve should also include the labyrinthine segment by a middle fossa approach. However, the middle fossa approach requires craniotomy and temporal lobe retraction, which increases the morbidity. The labyrinthine segment of the facial nerve can also be reached through mastoidectomy. However, many ear surgeons are not familiar with this approach due to the lack of anatomical data on this surgical area. Objective: To study the anatomical limitations of decompression of the labyrinthine segment via transmastoid approach. Methods: Complete mastoidectomy was performed in six adult cadavers heads. Dissection was extended in the zygomatic root and posterior bony wall of the external auditory canal to visualize the incudomallear joint completely. The bone between tympanic segment, lateral and superior semicircular canal's ampullas and middle fossa dural plate was removed. Fine dissection was carried out over tympanic segment of the facial nerve in an anterosuperomedial direction the labyrinthine segment was reached. Results: All the mastoids were well pneumatized. Distances between the labyrinthine segment and middle fossa dura, and between the labyrinthine segment and superior semicircular canal, were 2.5 and 4.5mm on average, respectively. In addition, distances between the middle fossa dura and dome of the lateral semicircular canal, and between the middle fossa dura and tympanic segment were 4.6 mm and 4.3 mm on average, respectively. Conclusion: It is possible to expose the labyrinthine segment of the facial nerve through mastoidectomy by dissecting the bone in the area between the tympanic segment of the facial nerve, middle fossa dural plate and ampullary ends of the lateral and superior semicircular canals.

Ectodermal dysplasia-skin fragility syndrome resulting from a new homozygous mutation, 888delC, in the desmosomal protein plakophilin 1.

We report an unusual case of an inherited disorder of the desmosomal protein plakophilin 1, resulting in ectodermal dysplasia-skin fragility syndrome. The affected 6-year-old boy had red skin at birth and subsequently developed skin fragility, progressive plantar keratoderma, nail dystrophy, and alopecia. Skin biopsy revealed widening of intercellular spaces in the epidermis and a reduced number of small, poorly formed desmosomes. Mutation analysis of the plakophilin 1 gene PKP1 revealed a homozygous deletion of C at nucleotide 888 within exon 5. This mutation differs from the PKP1 gene pathology reported in 8 previously published individuals with this rare genodermatosis. However, all cases show similar clinical features, highlighting the importance of functional plakophilin 1 in maintaining desmosomal adhesion in skin, as well as the role of this protein in aspects of ectodermal development.

Scanning electron microscopy of ciliae and saccharine test for ciliary function in septal deviations.

OBJECTIVE: To investigate the difference in mucociliary clearance and surface mucosal structure of the nasal septum and lateral nasal wall in patients with and without septal deviation. METHOD: The saccharine-dye test was used to measure the mucociliary clearance time in both nasal cavities of 20 patients with nasal septal deviation (study group) and was compared with that of 30 patients without septal deviation (control group). Bilateral septal and lateral nasal wall mucosal biopsies were taken from the study group during septoplasty, and unilateral biopsies were taken from 10 of the control group. These biopsies were studied under the scanning electron microscope. RESULTS: In the study group, mucociliary clearance on the side opposite the septal deviation was significantly slower than on the other side. Mucociliary clearance on both sides of the deviated septum of the study group was significantly slower than clearance in the control group. There was no statistically significant difference in the distribution of mucosal cilia of the cavities on either side of the deviated septum in the study group, nor between the distribution in the study group and controls. CONCLUSION: Patients with septal deviation display no change in mucosal surface anatomy but have decreased mucociliary activity on both sides of the deviation, the least activity being on the side opposite the deviation.

Ultrastructural changes in the circumventricular organs after experimental subarachnoid hemorrhage.

OBJECTIVES: Circumventricular organs (CVOs) are fine, periventricular, neurotransmitter-rich structures that are devoid of a blood-brain barrier and are known for their secretory role controlling fluid and electrolyte balance, thirst and even reproduction. Common pathologies of the brain such as trauma or bleeding affect CVOs, and hence their function. However, at what stage of these disease processes are CVOs affected and the time sequence of their recovery is still not clear. The aim of this study was to detect the morphological changes in CVOs using electron microscopy after experimental subarachnoid hemorrhage (SAH). METHODS: Experimental SAH was induced by transclival puncture of the basilar artery. Both scanning and transmission electron microscopic examination of the representive sections from each CVO was undertaken. RESULTS: Electron microscopy has shown that after SAH, the cells that form the CVOs exhibit signs of cellular necrosis with margination of the nucleus as well as cytoplasmic, mitochondrial and axonal edema. The subfornicial organ and organum vasculosum lamina terminalis appear to be more vulnerable to the effects of SAH than the median eminence or area postrema. DISCUSSION: Considering the fact that the experimental SAH model we have used is very similar to the momentary rupture of an aneurysm with secondary reflex spasm to seal the hole, it will not be unrealistic to consider that similar effects may also take place in the clinical setting.

Light and scanning electron microscopic examination of late changes in hair with hereditary trichodysplasia (Marie Unna hypotrichosis).

OBJECTIVE: Our aim was to investigate the microscopic surface structural alteration in hair with hereditary trichodysplasia. This article presents the results of light and scanning electron microscopy (SEM) examination of cases having hereditary trichodysplasia. METHODS: The biopsy specimens were obtained from 2 girls of ages 3 and 5-years, Department of Pediatrics, Faculty of Medicine, Hacettepe University in 2001. A large number of hair specimens were obtained from these 2 cases having hereditary trichodysplasia. Routine light microscopic and SEM procedure was performed on the tissue specimen, and then they were examined by light microscopy and SEM. RESULTS: Hair specimens taken from both patients had great similarities. Our results reveal that the atypical looking hair were flattened, twisted and partly scattered at the end. Moreover, these hairs had sheath structures with abnormal proliferation and these structures were damaged, the cuticles had fractures and were degenerative. CONCLUSION: There is only a small number of SEM studies in literature reporting the ultrastructural changes of hereditary trichodysplasia. Scanning electron microscopy is a 3 dimensional examination technique revealing easily comparable images and it is indispensable for diagnosis in various tissues which permit considerable magnification. As it is used in the hereditary trichodysplasia syndrome its routine usage in many dermatologic and hair diseases will result in valuable contributions to scientific literature.

The effect of vitamin D prophylaxis on radiation induced pulmonary damage.

Vitamin D has a selective radio and chemosensitizing effect on tumor cells. In vitro and in vivo studies have shown that vitamin D inhibits collagen gel construction, induces type II pneumocyte proliferation and surfactant synthesis in the lungs, and decreases vascular permeability caused by radiation. The aim of this experimental study was to determine if vitamin D has a protective effect against radiation-induced pulmonary damage. Adult Wistar rats were divided into 4 groups. Group 1 was comprised of control animals. Group 2, which was administered 0.25 µg/kg/day of vitamin D3 for 8 weeks, was the vitamin D control group. Rats in groups 3 and 4 were given 20 Gy right hemithorax radiotherapy, and in addition group 4 was given vitamin D3 treatment, which began the day before the radiotherapy and continued for 8 weeks. At the 8(th) and the 12(th) weeks of the study 4 rats from each group were sacrificed. Right lungs were dissected for light and electron microscopic study. The electron microscopy examinations revealed statistically significant differences between group 3 and 4, and in group 4 there was less interstitial inflammation and collagen deposition, and the alveolar structure and the cells lining the alveolar walls were protected. These results confirm that vitamin D has a protective effect against radiation-induced pulmonary toxicity. These findings should be evaluated with further clinical studies.

How DMSO, a widely used solvent, affects spinal cord injury.

The aim of this experimental study was to investigate whether dimethylsulfoxide (DMSO) has protective effects on spinal cord ischemia-reperfusion (I/R) injury. New Zealand rabbits were enrolled in the study. In addition to the control group, the study group received 0.1 mL/kg DMSO prior to ischemia. Blood samples were taken to obtain nitrite-nitrate levels during the surgical procedure. After neurological evaluation at 24 hr of reperfusion, lumbar spinal cords were removed for electron microscopic evaluation and malondialdehyde and myeloperoxidase measurements. The mean Tarlov score of the DMSO group was higher than that of the control group. Electron microscopic examination was carried out with tissue samples at 24 hr of reperfusion. The DMSO group had better preservation with the electron microscopic scoring compared to the control group. Malondialdehyde and myeloperoxidase levels were decreased in the DMSO group compared to the control group. Nitrite-nitrate levels were also lower in the DMSO group compared to control at 5 and 30 min of reperfusion. This study demonstrates a considerable neuroprotective effect of DMSO on neurological, biochemical, and histopathological analyses during periods of spinal cord I/R injury in rabbits. Although there was a difference between the DMSO and control groups in all measured parameters in our study, this was not statistically significant. DMSO deserves further investigation related with spinal cord ischemia and reperfusion. We should also consider the effect of DMSO when we use it as a solvent or vehicle during experimental I/R models.

In which period of injury is resveratrol treatment effective: ischemia or reperfusion?

The periods of ischemia and reperfusion represent different characteristics by lack of oxygen and reoxygenation. The aim of this experimental spinal cord injury model was to investigate whether resveratrol has protective effects during ischemia or reperfusion and the mechanism of the protection by using N-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase. Rabbits were divided into seven groups according to the time of administration of resveratrol or L-NAME (RI and RR, resveratrol during ischemia or reperfusion; IL and RL, L-NAME during ischemia or reperfusion; RILR, resveratrol during ischemia and L-NAME during reperfusion; LIRR, L-NAME during ischemia and resveratrol during reperfusion; control group). After neurologic evaluation at the twenty-fourth hour of reperfusion, lumbar spinal cords were removed for electron microscopic evaluation, immunohistochemical staining for apoptosis, and malondialdehyde (MDA) and myeloperoxidase (MPO) measurements. The RILR group had the best functional recovery, with a mean 3.6 Tarlov score (P < 0.05), and showed near normal electron microscopic findings (scores of 7.6 +/- 0.9 for the control group and 3.9 +/- 2.9 for the RILR group, P < 0.05). MPO and MDA levels were decreased in all groups compared with the control group, but only the decrement in the RILR group reached statistical significance. Immunohistochemical analysis showed that the groups including resveratrol and L-NAME together had the best staining for apoptosis. Resveratrol exhibits important protection by means of neurologic outcome, histopathologic analysis, and biochemical analysis, especially when used in during ischemia followed by L-NAME administration during reperfusion. Also, resveratrol protects against apoptosis, especially when combined with L-NAME.

Histologic characteristics of the human prepuce pertaining to its clinical behavior as a dual graft.

The aim of this study was to investigate the unique histologic structure of the normal human prepuce, paying particular attention to the resemblance and dissimilarities between the inner (ie, mucosa) and outer (ie, skin) layers. Histologic sections were stained using hematoxylin-eosin and Van Gieson stains. Transmission electron microscopy was used to evaluate the ultrastructure. Dense capillary networks can be observed in both the upper and lower dermal zones. The dermis lacks a dense collagenous zone. Melanocytes could not be observed in the mucosa. Elastin fibers and bundles were very abundant and dense. Early edema formation can be explained by the loose character of the dermal structure. Better graft "take" in mucosal grafts may be the result of the dense vascular dermal network. Mild hyperpigmentation can be explained by the limited number of melanocytes. However, this can also be observed in mucosal grafts, despite the absence of melanocytes. This may be solely the result of inflammatory hyperpigmentation, which can be seen in skin grafts. The abundance of elastin fibers in the prepuce may be the reason behind the superior wound contraction inhibition.

Effect of Mg2SO4 usage on spinal cord ischemia-reperfusion injury: electron microscopic and functional evaluation.

OBJECTIVES: To evaluate the effects of intravenous magnesium sulfate (Mg(2)SO(4)) administration on ischemia-reperfusion injury of the spinal cord. MATERIAL AND METHODS: Sixteen rabbits were randomly assigned to the control (group I, 8 rabbits) and the study group (group II, 8 rabbits). The abdominal aorta was clamped for a period of 30 min followed by a reperfusion period of 60 min. The animals in group II received 0.25 ml/kg/h Mg(2)SO(4) intravenous infusion (15% Mg(2)SO(4)) throughout this procedure. The animals were then observed for 24 h after which their neurological states were evaluated and tissue samples obtained from the spinal cord were examined with electron microscopy. RESULTS: Aortic pressure distal to the cross-clamp during the occlusion period was 9 +/- 3 mm Hg in group I and 19 +/- 6 mm Hg in group II. All animals in group I were paraplegic at the end of the study. In group II the neurological outcome of 1 animal was poor while the other 7 animals were neurologically in a good condition. Electron microscopic examinations of the spinal cord tissues of group I revealed severe injury but the ultrastructure was well preserved in group II. CONCLUSIONS: Intravenous Mg(2)SO(4) administration may have protective effects on the ischemia-reperfusion injury of the spinal cord. We propose that Mg(2)SO(4) may be an additional protective pharmacological agent in thoracal and thoracoabdominal aortic surgery.