N-acetylcysteine protects against cuprizone-induced demyelination: histological and immunohistochemical study

Myelination is a sequential process that is tightly controlled by a number of intrinsic and extrinsic factors. Any CNS disease in which the neuronal myelin sheath is damaged is referred to as demyelinating disease. The present work was designed to study the histopathological, ultrastructural and immunohistochemical changes in rat brain, mainly corpus callosum (CC), following oral administration of cuprizone (CPZ), and the role of N-acetylcysteine (NAC) in reducing these changes. Demyelination was induced by CPZ administration for short (4Ws) and long (8Ws) periods. NAC was given concomitantly and sequentially for similar periods. Spontaneous recovery after cessation of CPZ followed by no medication was also investigated. At the end of each experimental period, both cerebral hemispheres were extracted and prepared for light and electron microscopic examination and immuno-histochemical study. The obtained results showed a direct proportion between the duration of CPZ administration and the severity of demyelination. The co-administration of CPZ and NAC, had a fair protective impact that was stronger than the sequential administration of the two drugs. Incomplete spontaneous remyelination was observed after cessation of CPZ, being more evident in short than in long period group, indicating that when CPZ administration is prolonged, remyelination is delayed. In the light of the above results, it could be concluded that NAC has neuroprotective effects and has the potential to be a novel therapeutic approach for the treatment of demyelinating diseases such as multiple sclerosis; however, treatment should begin as soon as the disease manifests.

The relationship between the dimensions of the internal auditory canal and the anomalies of the vestibulocochlear nerve

BACKGROUND

Internal auditory canal (IAC) stenosis and vestibulocochlear nerve (VCN) abnormalities have been reported to be associated with sensorineural hearing loss. Previous studies classified the normal dimensions of the IAC and its anomalies with no consideration of the VCN. Other studies categorised the VCN development in only stenotic canals. In the present study, an anatomical classification of the normal dimensions of the IAC and its anomalies and their association with malformations of the VCN and its subdivisions were described.

MATERIALS AND METHODS

Retrospective review was undertaken for children ranged from 1 to 10 years. A total of 764 canals were investigated for pre-operative assessment of cochlear implantation. Other 100 canals of normal hearing ears were included as the control group. The maximum anteroposterior diameter, considered the width of the canal, was measured in axial plane and the length of the canal was identified in coronal plane. The canals were categorised normal: if they are from 3 to 8 mm, patulous: if they are more than 8 mm, stenotic: if they are less than 3 mm and atretic if absent, using multislice computed tomography. The VCN trunks and their subdivisions were investigated using magnetic resonance imaging.

RESULTS

Internal auditory canals were found normal in 66% with a mean width: 5.27 ± ± 0.68, patulous in 17% with a mean width 113% more than that of the control group (p = 0.000), stenotic in 13% with a mean width 73% less as compared to that of the control group (p = 0.000) and atretic in 4% of the experimental canals. The VCN trunks were found normal with well-developed subdivisions in 77.8% of the normal canals, 98.4% of the patulous canals, and 19.2% of the stenotic canals. The VCN trunks were normal with hypoplastic subdivisions in 11.3% of the normal canals, 1.6% in the patulous canals, and 61.6% in the stenotic canals with a mean width 52% less than that of the normal trunk with developed subdivisions. Hypoplastic VCN trunks with absent subdivisions were reported in 7.3% of the normal canals, 11.1% of the stenotic canals and in 3.2% of the atretic canals. The VCN trunks were not found in 3.6% of the normal canals, in 8.1% of the stenotic canals and in 96.8% of the atretic canals.

CONCLUSIONS

Internal auditory canal formation was dependent on the process of development and growth of the eighth cranial nerve and its subdivisions that greatly affected the completion of IAC canalisation. This paper could serve as a reference providing a quantitative classification of the relationship between the dimensions of the IAC and the development of the VCN trunk and its subdivisions.

Configuration of the circle of Willis and its two parts among Egyptian: a magnetic resonance angiographic study

BACKGROUND

We hypothesized that the collateral circulation differs in different ethnic groups. So, the aim of our work was to study variations of the circle of Willis (COW) among Egyptian and to compare our findings with the findings of other nationalities.

MATERIALS AND METHODS

One hundred patients were studied using magnetic resonance angiography (3D-TOF-MRA). Frequency and morphologic variations in COW were studied. The diameters of the arteries of the anterior and posterior circle were verified. Finally, the differences among the mean diameters of these arteries regarding age and sex were also studied.

RESULTS

Complete, partially complete and incomplete COW were encountered in 28%, 38% and 34% in the studied cases. The incomplete anterior circle was found in 34% (10% isolated incomplete anterior circle and 24% combined incomplete anterior and posterior circles) and the incomplete posterior circle came across in 62% (38% isolated incomplete posterior circle and 24% combined incomplete anterior and posterior circles). Seven anterior circle variations were found. The commonest type was the classical type "a" with a prevalence of 56%, being higher in male (57.1%). The 2nd common type was type "g" (hypoplasia or aplasia of the anterior communicating artery) with a prevalence of 24%, being higher in male (66.7%). Six posterior circle variations were found. The commonest variation was the classic type "a" with a prevalence of 26%, being higher in male (61.5%). Posterior circles types "d, e, h" (18%, 24%, 20%) constituted 62% and were characterised by hypoplasia/absent of the posterior communicating arteries.

CONCLUSIONS

The prevalence of complete COW (classic or textbook type) was encountered only 28% of the studied cases. Variations of COW were found to be more common in the posterior circulation (62%). The incomplete anterior circle was found in 34% and it is mostly caused by hypoplasia or aplasia of the anterior communicating artery which was found to be more common compared to the literature.

Subclinical sacroiliitis in brucellosis. Clinical presentation and MRI findings

PURPOSE

The aim of this work was to detect subclinical sacroiliac joint involvement in patients with brucellosis and study their clinical and laboratory features.

PATIENTS AND METHODS

The study included 100 brucellosis patients being followed-up in the Gastroenterology and Hepatology Unit, Theodor Bilharz Research Institute and Cairo University outpatient clinics. A thorough history, physical examination, routine laboratory tests, and abdominal ultrasound were obtained for all patients. Extended rheumatological examination was performed including clinical testing for sacroiliitis and enthesitis. None of the patients reported a history of back pain or any symptoms suggestive of sacroiliitis during the course of the infection. Plain x-ray and MRI scan of the sacroiliac joints were performed for all patients.

RESULTS

Asymptomatic sacroiliitis was present in 24 % of the brucellosis patients; none of the patients had tenderness over their spine with preserved lumbar spine mobility. Sacroiliitis was mainly unilateral being bilateral in 20.83 %. There was an obvious relationship with animal contact and occupation of the patients. Osteoarticular involvement was common (67 %) including arthralgias, arthritis, myalgias, spondylitis, enthesitis and bursitis, being clearly higher in those with sacroiliitis. The MRI scan showed blurring of the margins in 66.67 %, widening in 25 %, narrowing in 54.17 %, erosions in 20.83 %, and sclerosis in 12.5 %.

CONCLUSION

Osteoarticular manifestations of brucellosis are prevalent and subclinical sacroiliitis is evident, a finding that may classify these patients as having brucellar spondyloarthropathy (BSA). Referring brucellosis patients for rheumatological assessment has the advantage of early assessment of asymptomatic cases with sacroiliitis which is commonly overlooked.

beta-Endorphin and beta-lipotropin concentrations in umbilical cord blood

Antisera suitable for human beta-endorphin and beta-lipotropin radioimmunoassay were developed, and radioimmunoassays were established to measure these peptides in umbilical cord plasma, with silicic acid extraction and gel chromatography used to separate the beta-endorphin from the beta-lipotropin fraction. These two peptides were determined in umbilical venous plasma from 64 newborn infants. Umbilical vein beta-endorphin and beta-lipotropin concentrations averaged 38.5 +/- 3.2 and 50.4 +/- 4.1 (+/- SE) fmoles/ml in the 54 newborn infants without and 115 +/- 18 and 110 +/- 25 fmoles/ml in the 10 newborn infants with apparent fetal distress. Neither the presence or absence of labor nor the route or mode of delivery was found to affect umbilical vein beta-endorphin or beta-lipotropin concentrations. However, cord plasma levels of both peptides were significantly elevated in conjunction with fetal distress, as evidenced by prolonged bradycardia, late and prolonged variable fetal heart rate decelerations, or fetal acidosis. In 18 of 22 pairs of simultaneously measured umbilical venous and arterial beta-endorphin and beta-lipotropin concentrations in newborn infants without apparent intrapartum distress, the venous beta-endorphin concentrations, which averaged 40.4 +/- 3.5 fmoles/ml, were significantly higher than the arterial beta-endorphin levels, with a mean of 28.5 +/- 4.2 fmoles/ml. No significant umbilical arteriovenous concentration difference could be observed for beta-lipotropin. This suggests that at least a portion of the coad plasma beta-endorphin is derived from the placenta. The ratio of umbilical arterial to venous beta-endorphin concentrations rose as the absolute cord plasma beta-endorphin levels increased. Furthermore, both the molar umbilical venous and arterial beta-lipotropin to beta-endorphin ratios decreased significantly in association with intrapartum fetal distress. These data indicate tat the stress-related increase in umbilical plasma beta-endorphin exceeds that of beta-lipotropin and may be, at least in part, of fetal origin. Umbilical venous beta-endorphin and beta-lipotropin levels of neonates whose mothers did not receive meperidine or other narcotics agents did not differ from those of neonates whose mothers were given meperidine or other narcotics during labor. Our data, in conjunction with those of others, are consistent with the hypothesis that fetal hypoxia causes the release of neurotransmitters such as beta-endorphin, which may modulate the regulation of fetal heart rate patterns.