Intracytoplasmic sperm injection could minimize the incidence of prematurely condensed human sperm chromosomes

Objective: To compare the fertilization and prematurely condensed human sperm chromosomes (PCCs) rates between two intracytoplasmic sperm injection (ICSI) techniques.

Design: A retrospective study.

Setting: The data were obtained from the University of British Columbia in vitro fertilization (IVF) laboratory.

Patient(s): ICSI cycles (n = 105) were performed for couples suffering from severe male-factor infertility and dysfunction of fertilization.

Intervention(s): Two types of ICSI techniques were used for ICSI procedures.

Main Outcome Measure(s): Fertilization and pregnancy rates in group B using the improved ICSI technique were compared with those of group A using the standard ICSI technique. Unfertilized oocytes from the two groups were studied with cytogenetic methods.

Result(s): Oocyte damage dropped from 14.8% in group A to 5.3% in group B. Normal fertilization for each group was 57.3% and 88.4%, respectively (P<.05). Pregnancy rate per egg retrieval was 15.6% in group A and 27.4% in group B (P<.05). PCCs occurred in 19.4% of unfertilized oocytes in group A and did not occur in group B.

Conclusion(s): This study indicates that ICSI not only yields high fertilization rates, but also minimizes the incidence of PCCs. It may be directly related to two crucial steps (immobilization of sperm and aspiration of oocyte cytoplasm) used in ICSI procedures. This study also suggests that it is possible to overcome one cause of IVF failure resulting from the formation of PCCs by using the improved ICSI technique.     

Tensile strength of modified 4-strand cruciate technique for transversely or obliquely lacerated tendons

PURPOSES: To assess the tensile strength of the modified 4-strand cruciate technique for obliquely lacerated tendons, and to compare the findings with the strength of transversely lacerated tendons repaired at various grasping depths. METHODS: 60 porcine front foot tendons were evenly divided into 4 groups. In groups 1 to 3, tendons were transversely lacerated and repaired with grasping points at both ends away from the laceration by 5 mm, 10 mm, and 15 mm respectively. In group 4, tendons were obliquely lacerated and repaired with a grasping point 5 mm away from the laceration on one end and 15 mm on the other. All tendons were repaired with a modified 4-strand core suture and continuous epitendinous suture, and then tested to failure in a tensile machine. RESULTS: The tensile strength in group 1 was significantly lower than that in the other 3 groups (p<0.005). The tensile strength in group 4 was not significantly different from groups 2 and 3. CONCLUSION: The tensile strength of modified 4-strand cruciate repair configuration is not weakened in obliquely lacerated tendons; the grasping point at one end of the tendon being 15 mm away from laceration provides sufficient strength to compensate for the relatively weak 5-mm end. So long as one grasping point is away from the laceration site by 10 mm, the ultimate tensile strength of the transversely lacerated tendons appears acceptable. The modified 4-strand cruciate repair is safe to use for repairing obliquely lacerated tendons.     

Time‐varying effect moderation using the structural nested mean model: estimation using inverse‐weighted regression with residuals

This article considers the problem of examining time‐varying causal effect moderation using observational, longitudinal data in which treatment, candidate moderators, and possible confounders are time varying. The structural nested mean model (SNMM) is used to specify the moderated time‐varying causal effects of interest in a conditional mean model for a continuous response given time‐varying treatments and moderators. We present an easy‐to‐use estimator of the SNMM that combines an existing regression‐with‐residuals (RR) approach with an inverse‐probability‐of‐treatment weighting (IPTW) strategy. The RR approach has been shown to identify the moderated time‐varying causal effects if the time‐varying moderators are also the sole time‐varying confounders. The proposed IPTW+RR approach provides estimators of the moderated time‐varying causal effects in the SNMM in the presence of an additional, auxiliary set of known and measured time‐varying confounders. We use a small simulation experiment to compare IPTW+RR versus the traditional regression approach and to compare small and large sample properties of asymptotic versus bootstrap estimators of the standard errors for the IPTW+RR approach. This article clarifies the distinction between time‐varying moderators and time‐varying confounders. We illustrate the methodology in a case study to assess if time‐varying substance use moderates treatment effects on future substance use. Copyright © 2013 John Wiley & Sons, Ltd.     

Herpes zoster associated encephalitis in dialysis patients.

Two patients on dialysis because of chronic renal failure who developed herpes zoster associated encephalitis are reported. Both developed overt encephalopathy despite treatment with oral acyclovir for the preceding herpes zoster eruption. The encephalopathy responded rapidly to intravenous acyclovir.     

Cerebellopontine projections in the American opossum. A study of their origin, distribution and overlap with fibers from the cerebral cortex

The origin, course and distribution of cerebellopontine fibers was studied in the opossum by employing the Nauta-Gygax and Fink-Heimer techniques. Our results substantiate and extnd those of Brodal, Destombes, Lacerda and Angaut ('72) concerning the existence of cerebellopontine projections and provide evidence for a hitherto unreported fastigial projection to the basilar pons. Destruction of the caudal, medial division of the fastigial nucleus elicits bilateral degeneration in a restricted area of the medial pontine nucleus. This small terminal field is located in the angle between the medial lemniscus and the pyramidal tract and is found throughout the caudal three-fifths of the pons. The degenerating fibers do not course within the descending brachium conjunctivum, but reach the pons by filtering through the reticular formation from the uncinate fasciculus. Lesions that involve either the interpositus anterior or the dentate nucleus produce degeneration within the contralateral descending brachium conjunctivum and basilar pons. Terminal fields are located within the median, medial (paramedian nucleus of cat), peduncular, ventral and lateral nuclei. The heaviest degeneration is in the medial nucleus. Although cerebellar and cortical projections have different targets in the basilar pons, there is some overlap. Fastigial and preorbital fibers have partial overlap in the dorsal part of the medial nucleus, whereas the peduncular and lateral nuclei are the areas of overlap between the interpositus anterior and dentate projections with those from forelimb (and probably face) cortical areas. This overlap is particularly obvious in the caudal part of the lateral nucleus and occurs between fibers from limb motor-sensory cortex and those arising mainly within the anterior interpositus nucleus. There is no pontine overlap between cerebellar and visual or auditory cortical projections.     

The midtarsal joint locking mechanism

BACKGROUND: The midtarsal joint, consisting of the talo-navicular and the calcaneocuboid joints, is presumed to be responsible for the foot being both flexible and rigid during different parts of the stance phase of gait. However, this mechanism has never been well quantified. This study explores the midtarsal joint locking mechanism by comparing the effect of hindfoot inversion and eversion on midfoot and forefoot mobility. METHODS: Motion of the tibia, talus, calcaneus, navicular, cuboid and the first, second, and fifth metatarsals were measured in nine cadaver feet using Polhemus Fastrak electromagnetic sensors (EST GmbH and Co. KG, Kaiserslautern, Germany). The talus was fixed to the tibia, and then the forefoot was maximally dorsiflexed, plantarflexed, inverted, and everted, with the hindfoot in maximal eversion and inversion, for a total of eight test positions. The range of motion of the individual bones between maximal forefoot dorsiflexion and plantarflexion and between maximal forefoot inversion and eversion was calculated for the hindfoot in maximal eversion and inversion. RESULTS: For the range of motion from maximal dorsiflexion to maximal plantarflexion there was significantly increased movement of the first, second, and fifth metatarsals in the sagittal plane (p-value = 0.003, 0.007, and 0.002, respectively) when the calcaneus was maximally everted compared to when the calcaneus was maximally inverted. No significant differences were detected for the range of motion from forefoot inversion to eversion for the two hindfoot positions. CONCLUSIONS: This study demonstrated that motion in the forefoot is influenced by hindfoot position through the midtarsal joint. Specifically, the sagittal plane range of motion of the metatarsals is increased when the hindfoot is in valgus.     

Lupus nephritis in Chinese children – a territory-wide cohort study in Hong Kong

We report a multicenter study of Chinese children in Hong Kong with systemic lupus erythematosus (SLE) nephritis. Children were included if: they fulfilled the ACR criteria, had significant proteinuria or casturia, were Chinese and younger than 19 years and had been diagnosed with SLE between January 1990 and December 2003. Investigators in each center retrieved data on clinical features, biopsy reports, treatment and outcome of these patients. There were 128 patients (eight boys, 120 girls; mean age: 11.9±2.8 years). About 50% presented with multisystem illness and 40% with nephritic/nephrotic symptoms. Negative anti-dsDNA antibodies were found in 6% of the patients. Renal biopsy revealed WHO Class II, III, IV and V nephritis in 13 (10%), 22 (17%), 69 (54%) and 13 (10%) patients, respectively. The clinical severity of the nephritis did not accurately predict renal biopsy findings. The follow-up period ranged from 1 to 16.5 years (mean±SD: 5.76±3.61 years). During the study five patients died (two from lupus flare, one from cardiomyopathy, two from infections). Four patients had endstage renal failure (ESRF) (one died during a lupus flare). All deaths and end-stage renal failure occurred in the Class IV nephritis group. Chronic organ damage was infrequent in the survivors. The actuarial patient survival rates at 5, 10 and 15 years of age were 95.3, 91.8, and 91.8%, respectively. For Class IV nephritis patients, the survival rates without ESRF at 5, 10, and 15 years were 91.5, 82.3 and 76%, respectively. The survival and chronic morbidity rates of the Chinese SLE children in the present study are comparable to those of other published studies.An erratum to this article can be found at     

Regulation of ovarian follicular and luteal function during treatment with exogenous gonadotropins in anovulatory infertility

The dosage, duration of treatment, and plasma hormone levels were analyzed statistically between and within groups of treatment cycles with (n = 46) and without (n = 10) ovulation. A significant difference was observed in the dosage of human menopausal gonadotropins (hMG) over various days of treatment, but not in the mean dosage of hMG and human chorionic gonadotropin (hCG) administered per cycle. Follicle-stimulating hormone (FSH):luteinizing hormone (LH) ratios, prolactin (PRL) levels, and the magnitude and the duration of the estradiol response were greater in the ovulatory cycles. Additionally, in the ovulatory cycles, the dose of hMG correlated with the plasma levels of estradiol, FSH, and LH, while in the anovulatory cycles, hMG dosage correlated only with the LH concentrations. After administration of hCG, the mean plasma concentrations of its beta subunit peaked within 1 day and remained detectable for up to 10 days thereafter. In the ovulatory cycles, the mean progesterone level was maximal 6 days following hCG administration. In these cycles, luteal phase progesterone levels correlated positively with the preovulatory estradiol and inversely with concentrations of the beta subunit of hCG. The data demonstrate that, in contrast to anovulatory follicles, ovulatory follicles were exposed to a relative "dominance" of FSH over LH, with higher concentrations of estradiol and PRL for several days before hCG was administered. Apart from hMG dosage, the endogenous discharge of LH appeared to be an important determinant of the ovarian response. A single 10,000 IU dose of hCG was adequate for inducing ovulation and maintaining luteal function.