Sex-dimorphic effects of biogenesis of lysosome-related organelles complex-1 deficiency on mouse perinatal brain development.

The function(s) of the Biogenesis of Lysosome-related Organelles Complex-1 (BLOC-1) during brain development is to date largely unknown. Here, we investigated how its absence alters the trajectory of postnatal brain development using as model the pallid mouse. Most of the defects observed early postnatally in the mutant mice were more prominent in males than in females and in the hippocampus. Male mutant mice, but not females, had smaller brains as compared to sex-matching wild types at postnatal day 1 (P1), this deficit was largely recovered by P14 and P45. An abnormal cytoarchitecture of the pyramidal cell layer of the hippocampus was observed in P1 pallid male, but not female, or juvenile mice (P45), along with severely decreased expression levels of the radial glial marker Glutamate-Aspartate Transporter. Transcriptomic analyses showed that the overall response to the lack of functional BLOC-1 was more pronounced in hippocampi at P1 than at P45 or in the cerebral cortex. These observations suggest that absence of BLOC-1 renders males more susceptible to perinatal brain maldevelopment and although most abnormalities appear to have been resolved in juvenile animals, still permanent defects may be present, resulting in faulty neuronal circuits, and contribute to previously reported cognitive and behavioral phenotypes in adult BLOC-1-deficient mice.

Sleep/Wake Disruption in a Mouse Model of BLOC-1 Deficiency.

Mice lacking a functional Biogenesis of Lysosome-related Organelles Complex 1 (BLOC-1), such as those of the pallid line, display cognitive and behavioural impairments reminiscent of those presented by individuals with intellectual and developmental disabilities. Although disturbances in the sleep/wake cycle are commonly lamented by these individuals, the underlying mechanisms, including the possible role of the circadian timing system, are still unknown. In this paper, we have explored sleep/circadian malfunctions and underlying mechanisms in BLOC-1-deficient pallid mice. These mutants exhibited less sleep behaviour in the beginning of the resting phase than wild-type mice with a more broken sleeping pattern in normal light-dark conditions. Furthermore, the strength of the activity rhythms in the mutants were reduced with significantly more fragmentation and lower precision than in age-matched controls. These symptoms were accompanied by an abnormal preference for the open arm in the elevated plus maze in the day and poor performance in the novel object recognition at night. At the level of the central circadian clock (the suprachiasmatic nucleus, SCN), loss of BLOC-1 caused subtle morphological changes including a larger SCN and increased expression of the relative levels of the clock gene Per2 product during the day but did not affect the neuronal activity rhythms. In the hippocampus, the pallid mice presented with anomalies in the cytoarchitecture of the Dentate Gyrus granule cells, but not in CA1 pyramidal neurones, along with altered PER2 protein levels as well as reduced pCREB/tCREB ratio during the day. Our findings suggest that lack of BLOC-1 in mice disrupts the sleep/wake cycle and performance in behavioural tests associated with specific alterations in cytoarchitecture and protein expression.

Association Between Leisure Time Physical Activity, Cardiopulmonary Fitness, Cardiovascular Risk Factors, and Cardiovascular Workload at Work in Firefighters.

BACKGROUND: Overweight, obesity, and cardiovascular disease risk factors are prevalent among firefighters in some developed countries. It is unclear whether physical activity and cardiopulmonary fitness reduce cardiovascular disease risk and the cardiovascular workload at work in firefighters. The present study investigated the relationship between leisure-time physical activity, cardiopulmonary fitness, cardiovascular disease risk factors, and cardiovascular workload at work in firefighters in Hong Kong. METHODS: Male firefighters (n = 387) were randomly selected from serving firefighters in Hong Kong (n = 5,370) for the assessment of cardiovascular disease risk factors (obesity, hypertension, diabetes mellitus, dyslipidemia, smoking, known cardiovascular diseases). One-third (Target Group) were randomly selected for the assessment of off-duty leisure-time physical activity using the short version of the International Physical Activity Questionnaire. Maximal oxygen uptake was assessed, as well as cardiovascular workload using heart rate monitoring for each firefighter for four "normal" 24-hour working shifts and during real-situation simulated scenarios. RESULTS: Overall, 33.9% of the firefighters had at least two cardiovascular disease risk factors. In the Target Group, firefighters who had higher leisure-time physical activity had a lower resting heart rate and a lower average working heart rate, and spent a smaller proportion of time working at a moderate-intensity cardiovascular workload. Firefighters who had moderate aerobic fitness and high leisure-time physical activity had a lower peak working heart rate during the mountain rescue scenario compared with firefighters who had low leisure-time physical activities. CONCLUSION: Leisure-time physical activity conferred significant benefits during job tasks of moderate cardiovascular workload in firefighters in Hong Kong.

Bilateral substantia nigra and pyramidal tract changes following experimental intracerebral hemorrhage: an MR diffusion tensor imaging study.

The amelioration of secondary neurological damage is among the most important therapeutic goals for patients with intracerebral hemorrhage (ICH). Secondary injury of the ipsilateral substantia nigra (SN) and pyramidal tract (PY) is common after cerebral stroke. Such injury has been characterized previously by anatomical or diffusion MRI, but not in a comprehensive manner, and the knowledge regarding the contralateral changes is relatively poor. This study examined longitudinally both contralateral and ipsilateral SN and PY changes following experimental ICH with diffusion tensor imaging (DTI) and histology. ICH was induced in 14 Sprague-Dawley rats by the infusion of collagenase into the right striatum. Four-shot, spin-echo, echo-planar DTI was performed at 7 T with a b value of 1000 s/mm(2) and 30 diffusion gradient directions at 3.5 h and days 1, 3, 7, 14, 42 and 120 after ICH. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ// ) and radial diffusivity (λ┴ ) were measured in SN and PY accordingly. Two to three rats were sacrificed at days 3, 7, 42 and 120 for histology. The contralateral SN showed an increase in λ// with perivascular enlargement during the first 3 days after ICH. The ipsilateral SN showed increases in FA, λ// , λ┴ and MD at day 1, dramatic decreases at day 3 with neuronal degeneration and neuropil vacuolation, and subsequent gradual normalization. The contralateral PY showed diffusivity decreases at day 1. The ipsilateral PY showed early decreases and then late increases in MD and λ┴, and continuously decreasing FA and λ// with progressive axonal loss and demyelination. In summary, DTI revealed early bilateral changes in SN and PY following ICH. The evolution of the ipsilateral parameters correlated with the histological findings. In the ipsilateral PY, λ// and λ┴ changes indicated evolving and complex pathological processes underlying the monotonic FA decrease. These results support the use of quantitative multiparametric DTI for the evaluation of SN and PY injuries in clinical and preclinical investigations of ICH.

Measurement of liver T1 and T2 relaxation times in an experimental mouse model of liver fibrosis.

PURPOSE: To characterize changes in relaxation times of liver using quantitative magnetic resonance imaging (MRI) in an experimental mouse model of liver fibrosis. Quantitative MRI is a potentially robust method to characterize liver fibrosis. However, correlation between relaxation times and fibrosis stage has been controversial. MATERIALS AND METHODS: Liver fibrosis was induced in male adult C57BL/6N mice (22-25 g; n = 12) by repetitive dosing of carbon tetrachloride (CCl(4) ). The animals were examined with a series of spin-echo (SE) images with varying TRs and multiecho SE imaging sequence at 7 T before and 2, 4, 6, and 8 weeks after CCl(4) insult. Hepatic T(1) and T(2) values were measured. Histology was performed with hematoxylin-eosin staining and Masson's trichrome staining. RESULTS: Significant increase (P < 0.001) in hepatic T(1) was found at 2, 4, 6, and 8 weeks following CCl(4) insult as compared with that before insult. Meanwhile, hepatic T(2) at 2, 4, 6, and 8 weeks after CCl(4) insult was significantly higher (P < 0.001) than that before the insult. Liver histology showed collagen deposition, edema, and infiltration of inflammatory cells in livers with CCl(4) insult. CONCLUSION: Both longitudinal and transverse relaxation times may serve as robust markers for liver fibrosis. With the advent of single breath-hold sequences for MR relaxometry, quantitative mapping of relaxation times can be routinely and reliably performed in abdominal organs and hence may be valuable and robust in detecting liver fibrosis at early phase and monitoring its progression.

Liver fibrosis: an intravoxel incoherent motion (IVIM) study.

PURPOSE: To characterize longitudinal changes in molecular water diffusion, blood microcirculation, and their contributions to the apparent diffusion changes using intravoxel incoherent motion (IVIM) analysis in an experimental mouse model of liver fibrosis. MATERIALS AND METHODS: Liver fibrosis was induced in male adult C57BL/6N mice (22-25 g; n = 12) by repetitive dosing of carbon tetrachloride (CCl(4) ). The respiratory-gated diffusion-weighted (DW) images were acquired using single-shot spin-echo EPI (SE-EPI) with 8 b-values and single diffusion gradient direction. True diffusion coefficient (D(true) ), blood pseudodiffusion coefficient (D(pseudo) ), and perfusion fraction (P(fraction) ) were measured. Diffusion tensor imaging (DTI) was also performed for comparison. Histology was performed with hematoxylin-eosin and Masson's trichrome staining. RESULTS: A significant decrease in D(true) was found at 2 weeks and 4 weeks following CCl(4) insult, as compared with that before insult. Similarly, D(pseudo) values before injury was significantly higher than those at 2 weeks and 4 weeks after CCl(4) insult. Meanwhile, P(fraction) values showed no significant differences over different timepoints. For DTI, significant decrease in ADC was observed following CCl(4) administration. Fractional anisotropy at 2 weeks after CCl(4) insult was significantly lower than that before insult, and subsequently normalized at 4 weeks after the insult. Liver histology showed collagen deposition, the presence of intracellular fat vacuoles, and cell necrosis/apoptosis in livers with CCl(4) insult. CONCLUSION: Both molecular water diffusion and blood microcirculation contribute to the alteration in apparent diffusion changes in liver fibrosis. Reduction in D(true) and D(pseudo) values resulted from diffusion and perfusion changes, respectively, during the progression of liver fibrosis. IVIM analysis may serve as valuable and robust tool in detecting and characterizing liver fibrosis at early stages, monitoring its progression in a noninvasive manner.

Evaluation of holmium laser for managing mesh/suture complications of continence surgery.

OBJECTIVES: • To evaluate transurethral endoscopic excision using the holmium laser (TEEH) for the management of lower urinary tract mesh or suture complications of continence intervention. • To compare the outcomes, complications and recurrence rates of TEEH with the published results from studies using other techniques. PATIENTS AND METHODS: • A retrospective review of six patients who underwent TEEH for eroded mid-urethral tape or suture into the urethra or bladder. • Patients with urethral and bladder exposure of mesh or suture material managed by TEEH were identified from the operating records, electronic data records and the Holmium Laser Registry at our institution. • Outcome variables included resolution of the presenting symptoms and continence status, recurrent mesh or suture exposure, and symptoms or other morbidity, including haematoma, urinary sepsis, voiding dysfunction and recurrent stress incontinence. • A literature review on the available evidence on holmium laser for lower urinary tract complications of continence surgery was undertaken. RESULTS: • Between September 2006 and March 2010, six women underwent TEEH. All presented with bladder storage symptoms and/or haematuria with recurrent cystitis. The interval between surgery and the diagnosis of erosion was 1-13 years. • Four women had previously undergone retropubic mid-urethral tape, one colposuspension and one a suprapubic arc procedure followed by a transobturator tape insertion. • Complete excision with TEEH was achieved in all cases. • Two women had postoperative haematuria, which resolved after 2 weeks. There were no other immediate complications. • Four patients had recurrent erosion at follow-up. Two of them were symptomatic, requiring repeat TEEH. One was asymptomatic and managed expectantly. In one case, recurrent mesh erosion occurred at the bladder neck in the submucosal layer. This was considered unsuitable for further TEEH. A laparotomy and open excision was undertaken. CONCLUSIONS: • TEEH is a minimally invasive technique, with minimal morbidity and complications, compared to open vaginal or abdominal excision of mesh or suture exposure into the lower urinary tract. Open urethrotomy involves risks of damage to the continence (sphincter) mechanism, with subsequent stress incontinence. In addition, anterior wall scarring may lead to dyspareunia, vaginal pain, urethral stricture and/or fistula. When mesh erosion involves the bladder, transabdominal open or laparoscopic excision may be required. • Although the recurrence rates in our series are high, the majority of them were managed easily by repeat TEEH, with minimal morbidity or expectantly if asymptomatic. • In selected patients, TEEH is an acceptable novel technique for the first-line management of this complication of continence interventions, although longer or pooled prospective studies evaluating TEEH are now required.

Discovery of a fluoroindolo[2,3-a]carbazole clinical candidate with broad spectrum antitumor activity in preclinical tumor models superior to the marketed oncology drug, CPT-11.

A series of fluoroglycosylated fluoroindolocarbazoles was examined with respect to their topoisomerase I activity, cytotoxicity, and selectivity. The lead clinical candidate from this series, BMS-250749, displays broad spectrum antitumor activity superior to CPT-11 against some preclinical xenograft models, including curative antitumor activity against Lewis lung carcinoma.

Design and synthesis of a fluoroindolocarbazole series as selective topoisomerase I active agents. Discovery of water-soluble 3,9-difluoro-12,13-dihydro-13-[6-amino-beta-D-glucopyranosyl]-5H,13H-benzo[b]- thienyl[2,3-a]pyrrolo[3,4-c]carbazole- 5,7(6H)-dione (BMS-251873) with curative antitumor activity against prostate carcinoma xenograft tumor model.

A series of fluoroindolocarbazoles were studied with respect to their topoisomerase I activity, cytotoxicity, selectivity, and in vivo antitumor activity. Emerging from this series was BMS-251873, a potential clinical candidate possessing a robust pharmacological profile including curative antitumor activity against prostate carcinoma.