A case of naturally occurring visual field loss in a chimpanzee with an arachnoid cyst

Deficits in the occipital cortex have varying consequences among mammalian species. Such variations are indicative of evolutionary transitions in the striate cortical contribution to visually guided behavior. However, little is known about the role of the striate cortex in visually guided behavior in chimpanzees due to ethical concerns about invasive experiments and methodological limitations such as the inability to monitor gaze movements. We had the opportunity to study the behavioral consequences of a deficit in the occipital cortex in a chimpanzee with a naturally occurring arachnoid cyst in her right occipital lobe. We assessed the chimpanzee's ability to detect a small light probe (0.5 visual degree, Michelson contrast>0.9) presented at several locations in the visual field while monitoring gaze direction using an infra-red remote eye-tracker recently introduced to studies of great apes. The results showed the chimpanzee was unable to detect the probe in the lower left quadrant of the visual field, suggesting severe loss of contrast sensitivity in a part of hemivisual field that is retinotopically corresponded to the hemisphere of the cyst. A chimpanzee with a naturally occurring deficit in the right striate cortex and the availability of remote eye-tracking technology presented a unique opportunity to compare the role of the occipital lobe in visually guided behavior among various primate species.     

First update of the International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of porcine islet products in type 1 diabetes – Chapter 1: update on national regulatory frameworks pertinent to clinical islet xenotransplantation

Islet xenotransplantation represents an attractive solution to overcome the shortage of human islets for use in type 1 diabetes. The wide‐scale application of clinical islet xenotransplantation, however, requires that such a procedure takes place in a specifically and tightly regulated environment. With a view to promoting the safe application of clinical islet xenotransplantation, a few years ago the International Xenotransplantation Association (IXA) published a Consensus Statement that outlined the key ethical and regulatory requirements to be satisfied before the initiation of xenotransplantation studies in diabetic patients. This earlier IXA Statement also documented a disparate regulatory landscape among different geographical areas. This situation clearly fell short of the 2004 World Health Assembly Resolution WHA57.18 that urged Member States “to cooperate in the formulation of recommendations and guidelines to harmonize global practices” to ensure the highest ethical and regulatory standards on a global scale. In this new IXA report, IXA members who are active in xenotransplantation research in their respective geographic areas herewith briefly describe changes in the regulatory frameworks that have taken place in the intervening period in the various geographic areas or countries. The key reassuring take‐home message of the present report is that many countries have embraced the encouragement of the WHO to harmonize the procedures in a more global scale. Indeed, important regulatory changes have taken place or are in progress in several geographic areas that include Europe, Korea, Japan, and China. Such significant regulatory changes encompass the most diverse facets of the clinical application of xenotransplantation and comprise ethical aspects, source animals and product specifications, study supervision, sample archiving, patient follow‐up and even insurance coverage in some legislations. All these measures are expected to provide a better care and protection of recipients of xenotransplants but also a higher safety profile to xenotransplantation procedures with an ultimate net gain in terms of international public health.     

Impairment of the discrimination of the direction of single-whisker stimulation induced by the lemniscal pathway lesion

In the rodent somatosensory system, stimulus information received by the whiskers is relayed to the barrel cortex via two parallel pathways, the lemniscal pathway and the paralemniscal pathway. The lemniscal pathway includes the principal trigeminal nucleus (Pr5) and the ventral posteromedial thalamic nucleus (VPm). The paralemniscal pathway includes the spinal trigeminal subnucleus interpolaris (Sp5i) and the medial division of posterior thalamic nucleus (POm). The purpose of this study was to investigate the roles of those pathways in perceptions of the direction of the single-whisker stimulation in the rat. Rats were trained to perform a go/no-go task that required the discrimination of forward or backward stimulation applied to their single whisker. When a selective lesion was made in VPm or Pr5, error rate for the task performance increased significantly. In contrast, when a selective lesion was made in POm or Sp5i, we found no significant change in performance. These results suggest that the lemniscal pathway plays more important roles in a discrimination of stimulus direction applied to the single whisker.     

Predicting sustained virological response in chronic hepatitis C patients treated with pegylated interferon and ribavirin using a novel highly sensitive Real-time detection PCR assay

The Abbott Real Time HCV assay (lower limit of detection 12 IU/ml) was developed as a highly sensitive HCV RNA quantitative assay using real-time detection PCR(RTD-PCR). We assessed whether the new assay more effectively predicts sustained virological response (SVR) than conventional PCR (PCR) in 38 chronic hepatitis patients infected with HCV genotype 1b and treated with pegylated interferon alpha2b plus ribavirin. Sixteen patients reached SVR, 10 patients relapsed, 9 patients did not respond, 3 patients discontinued treatment. Positive predictive value (PPV) for SVR of undetectable HCV RNA at W4, 8, 12 by RTD-PCR and PCR was (100% vs. 100% at W4), (100% vs. 100% at W8), (83.3% vs. 72.7% at W12). HCV RNA undetectable at W12 had a higher PPV for SVR when measured by RTD-PCR than by conventional PCR.     

Clinical importance of impingement deformities for hip osteoarthritis progression in a Japanese population

Purpose

Femoroacetabular impingement is a new disease concept for hip disorders in young adults suggested as a major cause of primary hip osteoarthritis in Western countries. However, significant controversy exists regarding the prevalence and contribution of impingement deformities to osteoarthritis in Japan, owing to the higher prevalence of developmental dysplasia of the hip. Therefore, the aims of this study were to: (1) determine the prevalence of structural abnormalities associated with hip disorders in patients undergoing total hip replacement and (2) analyse the contribution of impingement deformities to osteoarthritis.

Methods

We analysed 250 patients from two different medical centres who underwent primary total hip replacement except those which were due to femoral head necrosis, posttraumatic osteoarthritis and systemic inflammatory disease. The average patient age at surgery was 64 years (range, 40–89 years), with 35 men and 215 women.

Results

Radiographic abnormality related to developmental dysplasia of the hip was associated with the majority of osteoarthritic hips (62 %). Hips with femoroacetabular impingement deformities were present within the cases categorized as unknown etiology. Cam impingement deformity was present in 22 % of unknown aetiology cases when cases with reactive osteophytes were excluded from all cam deformity cases (pistol grip deformity and aspherical femoral heads).

Conclusions

The prevalence of femoroacetabular impingement within primary osteoarthritis cases and gender predominance of impingement deformities are relatively similar to those reported previously in Western populations. This finding indicates that femoroacetabular impingement deformities are associated with osteoarthritis in the Japanese population, although it has a lower frequency among all hip failure patients.