Role of oxidative stress in streptozotocin-induced diabetic neuropathy in rats

To assess the contribution of oxidative stress in the pathophysiology of diabetic neuropathy and the possible protective effect of L-carnitine, coenzyme Q 10 [CoQ10] and acetylsalicylic acid [ASA] in streptozotocin-included diabetic neuropathy in rats. We also examined whether the studied drugs can promote satisfactory regeneration of sciatic nerve fibers following sciatic nerve crushing. Twenty rats were used as control and were divided into two groups. 10 rats each: Group I a was injected intraperitoneal [i.p.] by a single dose of saline and served as a control for group II a, group I b similar to group I a but with induced sciatic nerve crushing and served as control for group II b. Eighty rats were made diabetic by i.p streptozotocin [STZ] injection and were divided into: group II a [STZ-injected rats], group II b [STZ-injected rats with sciatic nerve crushing], groups III a, IV a and V a [STZ-injected rats treated with L-carnitine, CoQ1O and ASA respectively, for six weeks starting one week following STZ injection], groups III b, IV b and V b [STZ-injected rats,with sciatic nerve crushing, that received the same drugs as groups III a, IV a and V a]. At the end of the experimental period, distal motor latency [DL], maximum peak and peak to peak amplitude of compound muscle action potential [CMAP] were measured by percutaneous sciatic nerve stimulation. Blood samples were collected for measurement of plasma glucose and malondialdehyde [MDA] concentrations. The sciatic nerve was isolated for measuring reduced glutathione [GSH] concentration. STZ-injection induced diabetes, evidenced by significant higher mean value in plasma glucose concentration in groups IIa and IIb compared to that of the control groups Ia and Ib respectively. Significant sciatic nerve dysfunction could be observed, in the form of significantly prolonged DL and significantly decreased maximum peak and peak to peak amplitude of CMAP, in groups IIa and IIb compared to the control groups Ia and Ib respectively. STZ-injection resulted in oxidative stress evidenced by significant higher mean value in plasma MDA concentration and significant lower mean value in sciatic nerve GSH concentration in groups IIa and IIb compared to the control groups Ia and Ib respectively. Sciatic nerve crushing in group I b resulted in significant prolongation of DL and significant decrease in maximum peak and peak to peak amplitude of CMAP compared to group I a. Sciatic nerve crushing in group I b also resulted in significant lower mean value of sciatic nerve GSH concentration compared to group I a. The use of L-carnitine, CoQ10 as well as ASA, did not cause a significant change in plasma glucose concentration nor in body weight compared to groups IIa and IIb. The use of the above mentioned drugs improved oxidative stress parameters evidenced by significant lower mean value in plasma MDA concentration and significant higher mean value in sciatic nerve GSH concentration compared to groups IIa and IIb. The increase in sciatic nerve GSH concentration in groups III b and IV b that received L-carnitine and CoQ10 respectively, was significant compared to group Vb that received ASA as an antioxidant, whereas no significant difference in plasma MDA was found between different drug-treated groups. The use of the studied drugs resulted in significant improvement of DL as well as significant increase in maximum peak and peak to peak amplitude of CMAP compared to groups IIa and IIb. Group V a showed significant higher mean value in the maximum peak and peak to peak amplitude of CMAP compared to groups III a and IV a. Also group V b showed significant higher mean value in the maximum peak and peak to peak amplitude of CMAP compared to group III b. The results of the present study support the hypothesis that oxidative stress plays a key role in the pathophysiology of diabetic neuropathy and demonstrate that the use of antioxidants might have a protective role against diabetic neuropathy as well as a role in enhancing regeneration of functional nerve fibers. We recommend further human studies to evaluate the role of the addition of natural antioxidants, like L-carnitine or CoQ10, as well as ASA to the treatment regimen of diabetes, from the onset of the disease, in protection against diabetic neuropathy

Serum beta[2] - Microglobulin in acute and chronic hepatitis B and chronic hepatitis C

beta-2 micfoglobulin,[beta2 - M]-constilutes the B-chain of the major histocompatabilty complex [MHC] class-1 which is necessary for antigen presentation by ABC, serum level of P2-M, therefore may be useful in evaluation of immune response and subsequent cellular damage. In the present study an ELISA was used to measure serum p2-M level of 60 patients with various inflammatory liver diseases included: hepatitis B virus [acute and chronic], and chronic hepatitis C virus infection. Serum level of p2-M was significantly higher in all patients than normal subjects. The highest level of p2M was observed in patients with acute hepatitis B. Serum P2-M level was significantly correlated with the clinical presentation and liver function tests in patients with acute hepatitis B, but no correlation was noticed in patients with chronic hepatitis B. In chronic hepatisis C [HCV] patients a significant correlation of p2-M and ALT enzyme was observed, It could be concluded that: In acute and chronic liver diseases P2-M serum concentration seem to represent hepatocellular damage. Its level like serum am inotransfe rases could be used in diagnosis' of various inflammatory conditions of the liver

Abbreviations: used in this paper: HCV, hepatitis C virus; HBV, hepatitis B virus; HBs Ag, hepatitis B virus surface antigen; HCV Ab, hepatitis C virus antibody; MHC, major histocompitability

Effect of dietary energy on the superovulatory response to PMSG treatment, with special reference to embryo quality, metabolic and endocrine response in female goats

Thirty Baladi non lactating, goats were randomly allocated according to their dietary treatments into 3 groups. Group I [Restricted diet], group II [Flushing diet] and group III [High fat diet]. The oestrous cycle were synchronized with progestagen impregnated intravaginal sponges [MPA], for 14 days, followed by injection of PMSG at day 13, and HCG at day 14, for all female goates. At day 5-6 post oestrus, the embryos/ova were recovered surgically and examined for evaluation. The onset and duration of oestrus varied significantly between the groups. It appeared earlier in animals in group II and III than in group I. The total ovarian response, increased in group III and decreased in group II, compared with group I. However, the average number of normal corpora lutea was non significantly affected by feeding regimens. The data also revealed that, the total percentage of transferable embryos [grades 1, 2 and 3] was significantly elevated in groups II and III, compared with group I. Similarly the recovery rate was higher in groups II and III. At day of embryo recovery, the concentrations of serum progesterone have remarkable increase in groups II and III. In addition, the level of estradiol-17beta recorded a peak level at the day of oestrus. This level dropped to record a lowest values at day of embryo recovery. Serum triglycerides, cholesterol and HDL-CH were lowered in feed restricted diet compared with high fat level. Regarding serum insulin concentration, goats received the energy restricted diet had a significant decrease in serum insulin level than those received flushing or high fat diets. It is concluded that the level of dietary energy had a significant effect on the onset and duration of oestrus, ovarian activity and quality of embryos available for transfer, but increased the number of unovulatory follicles

Relationship between body condition, milk yield and reproductive performance of dairy cows

To study the relationship between body condition, milk yield and reproductive perfomance of highly producing dairy cows under local conditions, a number of 287 Holstein-Friesian cows, in their 1[st] to 5[th] lactation were used. Animals were grouped according to their milk production and fed on a total mixed ration according to NRC 1989. All cows were evaluated subjectively for body condition score [BCS] at calving and at service. Linear regression coefficient of interval from calving to 1[st] estrus [Y1] on peak milk yield/kg/day [X1] was significant [P < 0.01]. The resulting equation was Y1=16.37+0.7X1. Cows with higher peak milk yield showed a significant long interval to 1[st] detected estrus. No significant linear regression was found between milk yield/kg during current lactation and reproductive traits. Linear regression coefficient of interval from parturition to 1[st] detected estrus [Y1] on BCS at calving up to score 4.0 [X2] was significant [P < 0.01]. The resulting equation was Y1=90.52-20.68 X2. Cows with high BCS at calving up to score 4.0 had significantly [P < 0.05] shorter interval to 1[st] detected estrus. Meanwhile, linear regression coefficient of days open [Y2] or number of services/conception [Y3] on BCS at service [up to score 3.5] [X3] was also significant. The resulting equations were Y2 = 293.59 - 66.47 X3 and Y3=5.13-1.056 x 3, respectively. Both days open and number of services/conception were significantly improved as BCS at service was increased up to 3.5. The present work revealed that, reduced fertility in highly producing cows is not directly related to increased milk yield but rather to loss of weight and body condition. It is worthy to mention that the equations used here are helpful to predict the reproductive perfomance of a given cow by means of peak milk yield and/or BCS

Induced spherical aberration of ultra-thin hydrogel lenses after fitting

The spherical aberration of some ultra-thin hydrogel soft contact lenses was studied before and after fitting. Change in spherical aberration was observed and it was always negative where its value after fitting was less than before. This change is unpredictable and irregular, having no direct relationship with the corneal and lens curvatures. It was also noticed that the spherical aberration decreases with increased power in lenses with aspheric posterior surface

Changes in the shape and power of ultra-thin soft lenses after fitting

A study of the performance of ultra-thin soft contact lenses with aspheric posterior surface when fitted on myopic patients was tried. Refraction and photokeratoscopy were done prior to and after fitting of spin cast lenses with the same anterior surface but different aspheric posterior surfaces, which entitles different powers according to the manufacturer's specifications. The changes in power and shape of each lens were studied. The results show that the moulding of these lenses on the corneal surface leads to changes in the resultant power and shape of the lens which may cause changes of visual acuity and unpredictable astigmatism. An empirical formula that correlates the changes in the curvature of the lens and corneal curvature was reached