Expression and functional behavior of troponin C in soleus muscle fibers of rat after hindlimb unloading

Troponin C (TnC) plays a key role in the regulation of muscle contraction, thereby modulating the Ca(2+)-activation characteristics of skinned muscle fibers. This study was performed to assess the effects of a 15-day hindlimb unloading (HU) period on TnC expression and its functional behavior in the slow postural muscles of the rat. We investigated the TnC isoform expression in whole soleus muscles and in single fibers. The latter were also checked for their Ca(2+) activation characteristics and sensitivity to bepridil, a Ca(2+) sensitizer molecule. This drug has been described as exerting a differential effect on slow and fast fibers, depending on the TnC isoform. With regard to TnC expression, three populations were found in control muscle fibers: slow, hybrid slow, and hybrid fast fibers, with the TnC fast being always coexpressed with TnC slow. In the whole muscle, TnC fast expression increased after HU because of the increase in the proportion of hybrid fast fibers. The HU hybrid fast fibers had properties similar to those of control hybrid fast fibers. The fibers that remained slow after HU exhibited similar bepridil and Sr(2+) properties as control slow fibers. Therefore, in these fibers, the changes could not be related to the TnC molecule.

Influence of socio-economic deprivation on the prevalence and outcome of depression in primary care: the Hampshire Depression Project

BACKGROUND

Health inequalities exist for many disorders, but the contribution of deprivation to the prevalence and outcome of depressive symptoms in primary care populations has been infrequently studied.

AIMS

To examine the influence of Jarman under-privileged area (UPA) scores on the prevalence and outcome of depressive symptoms in general practice patients.

METHOD

18 414 patients attending 55 representative practices completed the Hospital Anxiety and Depression Scale and a questionnaire for employment status. Outcome of those screening positive was assessed at 6 weeks and 6 months.

RESULTS

The UPA score accounted for 48.3% of the variance between practices in prevalence of depressive symptoms. Attending a high UPA score practice predicted persistence of depressive symptoms to 6 months.

CONCLUSIONS

The socio-economic deprivation of a practice locality is a powerful predictor of the prevalence and persistence of depressive symptoms.

Supporting parents of children with communication difficulties: a model

The project focuses on 'shared listening' from a structured developmental framework of 'sound/no sound awareness' to basic 'phonological awareness' linking it to the Foundation Curriculum: Early Years Goals (Department for Education and Employment 2000) and National Literacy Framework (Department for Education and Employment 1998). The project is based around parents borrowing topic bags where their children have been identified by speech and language therapy/specialist language and communication support teachers as having listening/phonological difficulties. Following a simple screening assessment parents borrow the bags weekly for a potential 30 weeks. These have been shown to have an effect on both parental attitudes to helping listening (practically-based and focused) and their children's listening skills.

Effects of unweighting and clenbuterol on myosin light and heavy chains in fast and slow muscles of rat

To investigate the plasticity of slow and fast muscles undergoing slow-to-fast transition, rat soleus (SOL), gastrocnemius (GAS), and extensor digitorum longus (EDL) muscles were exposed for 14 days to 1) unweighting by hindlimb suspension (HU), or 2) treatment with the beta(2)-adrenergic agonist clenbuterol (CB), or 3) a combination of both (HU-CB). In general, HU elicited atrophy, CB induced hypertrophy, and HU-CB partially counteracted the HU-induced atrophy. Analyses of myosin heavy (MHC) and light chain (MLC) isoforms revealed HU- and CB-induced slow-to-fast transitions in SOL (increases of MHCIIa with small amounts of MHCIId and MHCIIb) and the upregulation of the slow MHCIa isoform. The HU- and CB-induced changes in GAS consisted of increases in MHCIId and MHCIIb ("fast-to-faster transitions"). Changes in the MLC composition of SOL and GAS consisted of slow-to-fast transitions and mainly encompassed an exchange of MLC1s with MLC1f. In addition, MLC3f was elevated whenever MHCIId and MHCIIb isoforms were increased. Because the EDL is predominantly composed of type IID and IIB fibers, HU, CB, and HU-CB had no significant effect on the MHC and MLC patterns.

Cutaneous epithelioid malignant nerve sheath tumor with rhabdoid features: a histologic, immunohistochemical, and ultrastructural study of three cases

INTRODUCTION

Malignant rhabdoid tumors are morphologically defined as sheets of loosely cohesive cells with eccentric nuclei and hyaline, paranuclear inclusions. Although originally described as a distinctive renal neoplasm of childhood, these tumors have since been described in all age groups and in a variety of extrarenal sites. In the latter setting, it is thought that the rhabdoid phenotype is comprised of histogenetically unrelated tumors, that regardless of histogenesis, pursue a biologically aggressive behavior.

METHODS

We report on the clinical, histologic, immunophenotypic, and ultrastructural characteristics of three cases of cutaneous malignant rhabdoid tumor.

RESULTS

Each of the cases arose on the trunk or the extremity of elderly men. None of the patients had neurofibromatosis. All of the lesions histologically showed sheets of loosely cohesive polygonal cells with eccentric nuclei and hyaline paranuclear inclusions. Each of the cases showed the following immunophenotype: S-100 (+), synaptophysin(+), vimentin (+), alpha smooth muscle actin (-), CD-30 (-), HMB-45 (-), and pankeratin(-). Ultrastructure of two of the cases yielded similar results showing paranuclear filamentous aggregates of intermediate filaments, cell membrane dense plaques, and rudimentary cell junctions consistent with nerve sheath differentiation. Tonofilaments, dense bodies, microtubules, neurosecretory granules, and melanosomes were not identified. Each of the patients died of widely metastatic disease within 1 year of diagnosis.

CONCLUSIONS

Cutaneous epithelioid malignant nerve sheath tumor is a potentially aggressive tumor capable of showing rhabdoid differentiation thus simulating a variety of neoplasms. Immunophenotyping and ultrastructural analysis reliably discriminates these lesions from melanoma, de-differentiated carcinoma, lymphoma, and rhabdomyosarcoma.

Gambling in the south: implications for physicians

Three historical cycles of legalized gambling have occurred in the South. Currently, every southern state has legalized some form of gaming. Adult past-year prevalence rates of problem gambling in southern states are within the national range. Higher prevalence rates occur in states with casinos and multiple forms of legalized gambling. States with lotteries have higher prevalence rates of adolescent problem gambling. Problem gambling can cause stress-induced physical diseases and psychiatric symptoms in gamblers and their families. Physicians can reduce personal, family, and social costs of problem gambling through increased awareness, strategic screening, and early intervention. Treatment approaches include inpatient treatment centers, self-help fellowship groups, and cognitive-behavioral and addiction-based psychotherapies. Although no standard pharmacologic treatments for gambling disorders exist, use of selective serotonin re-uptake inhibitors is under investigation. Referral resources are available to physicians in states with state-funded treatment programs for problem gamblers and/or state councils for problem gambling.

Upregulation of myosin heavy chain MHClalpha in rat muscles after unweighting and clenbuterol treatment

Myosin heavy chain (MHC) mRNA isoforms were quantified in soleus (SOL) and gastrocnemius (GAS) muscles from rats exposed to 14 days of either hindlimb unweighting (HU), clenbuterol treatment (CB), or HU combined with CB treatment (HU-CB). All conditions induced in SOL a shift from slow to faster MHC mRNA isoforms and an upregulation of MHClalpha. Increases were highest with CB, lowest with HU-CB, and coincided mainly with elevations in MHClla mRNA isoforms. The changes in MHC mRNA levels in GAS muscle corresponded to fast-to-faster transitions. Elevations in MHClalpha mRNA were smaller than in SOL and seemed to occur in parallel with decreases in MHClbeta. Taken together, our results suggested that MHClalpha is expressed in transforming rat slow and fast muscles, most likely as an intermediate step between MHClbeta and MHClla.

The mycosins of Mycobacterium tuberculosis H37Rv: a family of subtilisin-like serine proteases

There is little information regarding the role of proteolysis in Mycobacterium tuberculosis and no studies on the potential involvement of proteases in the pathogenesis of tuberculosis. We identified five M. tuberculosis genes (mycP1-5) that encode a family of serine proteases (mycosins-1 to 5), ranging from 36 to 47% identity. Each protein contains a catalytic triad (Asp, His, Ser) within highly conserved sequences, typical of proteases of the subtilisin family. These genes are also present in M. bovis BCG and other virulent mycobacteria, but only one homologue (mycP3) was detected in M. smegmatis. The mycosins have N-terminal signal sequences and C-terminal transmembrane anchors, and the localisation of the mycosins to the membrane/cell wall was verified by Western blot analysis of heterologously expressed proteins in cellular fractions of M. smegmatis. In M. tuberculosis, all the mycosins were expressed constitutively during growth in broth. Mycosins-2 and 3 were also expressed constitutively in M. bovis BCG, but no expression of mycosin-1 was detected. Mycosin-2 was modified by cleavage in all three mycobacterial species. The multiplicity and constitutive expression of these proteins suggests that they have an important role in the biology of M. tuberculosis.

Case-control study of laparoscopic versus abdominal myomectomy

PURPOSE

To compare laparoscopic with abdominal approaches to myomectomy.

PATIENTS AND METHOD

Frequency matching was used to ensure similar fibroid weights among the laparoscopic and abdominal groups in this case-control study. The study group consisted of prospectively recruited patients undergoing laparoscopic (N = 5) or laparoscopically assisted (N = 20) myomectomy (lap). The control group represented both prospectively (N = 14) and retrospectively (N = 37) identified abdominal myomectomy patients (abd). Analysis of the variables was performed using a t-test, Wilcoxon rank-sum test, chi-square test, or analysis of covariance at the 0.01 significance level.

RESULTS

All results are reported after matching for fibroid weight, with the median (quartiles) aggregate weight measuring 151 g (31.0, 262.0) and 170.0 g (81.0, 285.0) for the lap and abd patients, respectively (P = 0.15). Median (quartiles) length of hospital stay (30.5 hours [25.0, 52.5] v 65.0 hours [45.0, 76.0]; P < 0.001) and duration of postoperative intravenous narcotic use (14.8 hours [3.0, 18.5] v 24.0 hours [18.0, 40.0]; P = 0.001) were significantly shorter for the lap patients. The laparoscopic cases required a longer median operative time (222.5 minutes [192.5, 270.0]) than the abdominal cases (180.0 minutes [160.0, 220.0]; P = 0.001). No difference was detected in estimated blood loss from surgery (P = 0.57).

CONCLUSIONS

A laparoscopic approach to myomectomy may be safely chosen for patients with fibroids and offers the benefits of less postoperative intravenous narcotic use, a shorter hospital stay, and no greater intraoperative blood loss than abdominal myomectomy.

Male-killing Wolbachia in a flour beetle

The bacteria in the genus Wolbachia are cytoplasmically inherited symbionts of arthropods. Infection often causes profound changes in host reproduction, enhancing bacterial transmission and spread in a population. The reproductive alterations known to result from Wolbachia infection include cytoplasmic incompatibility (CI), parthenogenesis, feminization of genetic males, fecundity enhancement, male killing and, perhaps, lethality Here, we report male killing in a third insect, the black flour beetle Tribolium madens, based on highly female-biased sex ratios of progeny from females infected with Wolbachia. The bias is cytoplasmic in nature as shown by repeated backcrossing of infected females with males of a naturally uninfected strain. Infection also lowers the egg hatch rates significantly to approximately half of those observed for uninfected females. Treatment of the host with antibiotics eliminated infection, reverted the sex ratio to unbiased levels and increased the percentage hatch. Typically Wolbachia infection is transmitted from mother to progeny, regardless of the sex of the progeny; however, infected T. madens males are never found. Virgin females are sterile, suggesting that the sex-ratio distortion in T. madens results from embryonic male killing rather than parthenogenesis. Based on DNA sequence data, the male-killing strain of Wolbachia in T. madens was indistinguishable from the CI-inducing Wolbachia in Tribolium confusum, a closely related beetle. Our findings suggest that host symbiont interaction effects may play an important role in the induction of Wolbachia reproductive phenotypes.

Binaural-beat induced theta EEG activity and hypnotic susceptibility

Six participants varying in degree of hypnotizability (2 lows, 2 mediums, and 2 highs) were exposed to 3 20-minute sessions of a binaural-beat sound stimulation protocol designed to enhance theta brainwave activity. The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) was used for pre- and post-stimulus measures of hypnotic susceptibility. A time-series analysis was utilized to evaluate anterior theta activity in response to binaural-beat sound stimulation over baseline and stimulus sessions. The protocol designed to increase anterior theta activity resulted in a significant increase in percent theta for 5 of 6 participants. Hypnotic susceptibility levels remained stable in the high-susceptible group and increased significantly in the low and medium-susceptible groups.

Repair of the radial free flap donor site with full or partial thickness skin grafts. A prospective randomised controlled trial

The radial forearm free flap has become the mainstay in the reconstruction of soft tissue defects following ablative resection in the oral cavity. The method of repair of the associated forearm tissue defect has been the subject of considerable debate. The options range from direct closure, to local soft tissue flaps or skin graft repair. Larger defects usually require a skin graft and we have routinely used partial thickness skin. An audit of our complication rate led to the consideration of whether a full thickness repair would reduce the morbidity. We randomly allocated successive patients to receive full or partial thickness skin graft repair of the radial donor site in a consecutive series of 68 patients over an 18-month period. Sixty-four patients completed the initial assessment period of wound healing. Thirty seven patients completed a questionnaire at one year to subjectively assess the aesthetic appearance of the forearm wound and the skin graft donor site. They were also assessed for pain at both sites. The partial thickness donor site required significantly more re-dressings. There was no significant difference between the two groups in graft take or number of re-dressings at the recipient site. There was no significant difference in patient assessment of aesthetic appearance or pain in either the forearm recipient site or the skin graft donor site. Provided that an adequate graft is taken, full thickness and partial thickness skin grafts have the same short-term and long-term outcomes in the repair of the radial free flap donor site.

Robotic-assisted laparoscopic microsurgical tubal anastomosis: a human pilot study

OBJECTIVE

To evaluate the feasibility and safety of a robotic device to perform a laparoscopic tubal anastomosis.

DESIGN

Prospective pilot study.

SETTING

Tertiary care medical center.

PATIENT(S)

Ten patients with previous tubal ligations underwent laparoscopic tubal ligation reversal using a robotic suturing device.

INTERVENTION(S)

Tubal surgery was performed with a robotic system. A two-layered closure was used for all tubes. Four stitches of 8-0 polygalactin sutures were used for each layer.

MAIN OUTCOME MEASURE(S)

Tubal patency; secondary measures were pregnancy rates, complications, and operative time.

RESULT(S)

The procedure was completed successfully in all 10 patients. No patient required conversion to an open procedure. The mean time (+/-SD) required to complete the anastomosis of both tubes was 159 +/- 33.8 minutes. Chromotubation at the end of the procedure showed patency in all tubes anastomosed. A postoperative hysterosalpingogram 6 weeks after surgery demonstrated patency in 17 of the 19 (89%) tubes anastomosed. There have been five pregnancies so far. There were no complications.

CONCLUSION(S)

Robotic technology can be used safely to create laparoscopic microsurgical anastomoses with adequate patency rates. Robotic technology has the potential to make laparoscopic microsuturing easier.

Alterations in contractile properties and expression of myofibrillar proteins in wobbler mouse muscles

The purpose of this study was to characterize the alterations in muscle contractile (tension-pCa relationship) and biochemical (myosin heavy and light chains, troponin C content) properties in a hereditary motoneuron disease. The study was performed on wobbler mouse mutants which presented a neuronal degeneration. The time course of the disease was followed at 5 and 7 weeks in sternocleidomastoid (SCM) and soleus muscles. The wobbler disease was found to induce a shift from fast to slow myosin heavy-chain isoform expression in SCM and soleus muscles. The analysis of the myosin light-chain (MLC) composition revealed, for the SCM muscles, the appearance of the slow isoforms at 5 weeks and an increase in the regulatory MLC2 content at 7 weeks. A significant increase in the slow troponin C isoform content was found in both types of wobbler muscles at 7 weeks. The wobbler soleus and SCM muscles presented an age- and fiber-type-related atrophy, characterized by a decline in absolute maximal tension and fiber diameter. A decrease in calcium sensitivity was observed at 7 weeks for the soleus fibers and at both 5 and 7 weeks for the SCM. The results indicated fast-to-slow changes in contractile and biochemical properties of the wobbler soleus and SCM muscles, which occurred during the motoneuron degeneration process previously described in the wobbler pathology.

Repeated measures in clinical trials: simple strategies for analysis using summary measures

The summary measures approach to analysing repeated measures is described. The circumstances under which it can be advantageous to use such measures are considered. Strategies for baseline adjustment where there are multiple baselines are examined, as is the choice of appropriate summary statistic. A compromise trend/mean measure, regression through the origin, is proposed as being useful under some circumstances. An analysis using this measure is illustrated with a suitable example.

Effects of beta(2)-agonist clenbuterol on biochemical and contractile properties of unloaded soleus fibers of rat

The effects of clenbuterol beta(2)-agonist administration were investigated in normal and atrophied [15-day hindlimb-unloaded (HU)] rat soleus muscles. We showed that clenbuterol had a specific effect on muscle tissue, since it reduces soleus atrophy induced by HU. The study of Ca(2+) activation properties of single skinned fibers revealed that clenbuterol partly prevented the decrease in maximal tension after HU, with a preferential effect on fast-twitch fibers. Clenbuterol improved the Ca(2+) sensitivity in slow- and fast-twitch fibers by shifting the tension-pCa relationship toward lower Ca(2+) concentrations, but this effect was more marked after HU than in normal conditions. Whole muscle electrophoresis indicated slow-to-fast transitions of the myosin heavy chain isoforms for unloaded and for clenbuterol-treated soleus. The coupling of the two latter conditions did not, however, increase these phenotypical transformations. Our findings indicated that clenbuterol had an anabolic action and a beta(2)-adrenergic effect on muscle fibers and appeared to counteract some effects of unloading disuse conditions.

Variation in the production and distribution of substituted benzoquinone compounds among genetic strains of the confused flour beetle, Tribolium confusum

Insects often produce chemicals, such as defensive compounds, whose quantity and distribution can affect their fitness. For evolution to produce adaptations, chemical production must be genetically variable. Here we report the results of a study using high-performance liquid chromatography to quantify two important chemical secretions of the flour beetle Tribolium confusum, methyl-1, 4-benzoquinone (MBQ) and ethyl-1,4-benzoquinone (EBQ). Our results show a distinct difference in the production of the compounds among four genetically distinct strains of T. confusum (b-+, b-I, b-IV, b-Pakistan) with an unusually high amount measured for the b-Pakistan strain. By measuring internal and external benzoquinone levels separately, we were also able to detect differences in production and distribution of the compounds between the strains. Some strains secrete more of the chemicals, whereas other strains appear to sequester the compounds within their bodies. The sexes also differ in total quinone production as well as in their internal to external benzoquinone ratios, suggesting the trait is sex influenced. Finally, a consistent correlation in the amounts of MBQ to EBQ in individual beetles suggests that the substituted benzoquinones share a common precursor or pathway.

Regulation of the resident chromosomal copy of c-myc by c-Myb is involved in myeloid leukemogenesis

c-myb is a frequent target of retroviral insertional mutagenesis in murine leukemia virus-induced myeloid leukemia. Induction of the leukemogenic phenotype is generally associated with inappropriate expression of this transcriptional regulator. Despite intensive investigations, the target genes of c-myb that are specifically involved in development of these myeloid lineage neoplasms are still unknown. In vitro assays have indicated that c-myc may be a target gene of c-Myb; however, regulation of the resident chromosomal gene has not yet been demonstrated. To address this question further, we analyzed the expression of c-myc in a myeloblastic cell line, M1, expressing a conditionally active c-Myb-estrogen receptor fusion protein (MybER). Activation of MybER both prevented the growth arrest induced by interleukin-6 (IL-6) and rapidly restored c-myc expression in nearly terminal differentiated cells that had been exposed to IL-6 for 3 days. Restoration occurred in the presence of a protein synthesis inhibitor but not after a transcriptional block, indicating that c-myc is a direct, transcriptionally regulated target of c-Myb. c-myc is a major target that transduces Myb's proliferative signal, as shown by the ability of a c-Myc-estrogen receptor fusion protein alone to also reverse growth arrest in this system. To investigate the possibility that this regulatory connection contributes to Myb's oncogenicity, we expressed a dominant negative Myb in the myeloid leukemic cell line RI-4-11. In this cell line, c-myb is activated by insertional mutagenesis and cannot be effectively down regulated by cytokine. Myb's ability to regulate c-myc's expression was also demonstrated in these cells, showing a mechanism through which the proto-oncogene c-myb can exert its oncogenic potential in myeloid lineage hematopoietic cells.

Effects of a clinical-practice guideline and practice-based education on detection and outcome of depression in primary care: Hampshire Depression Project randomised controlled trial

BACKGROUND

Depression is a major individual and public-health burden throughout the world and is managed mainly in primary care. The most effective strategy to reduce this burden has been believed to be education of primary-care practitioners. We tested this assumption by assessing the effectiveness of an educational programme based on a clinical-practice guideline in improving the recognition and outcome of primary-care depression.

METHODS

We carried out a randomised controlled trial in a representative sample of 60 primary-care practices (26% of the total) in an English health district. Education was delivered to practice teams and quality tested by feedback from participants and expert raters. The primary endpoints were recognition of depression, defined by the hospital anxiety and depression (HAD) scale, and clinical improvement. Analysis was by intention to treat.

FINDINGS

The education was well received by participants, 80% of whom thought it would change their management of patients with depression. 21409 patients were screened, of whom 4192 were classified as depressed by the HAD scale. The sensitivity of physicians to depressive symptoms was 39% in the intervention group and 36% in the control group after education (odds ratio 1.2 [95% CI 0.88-1.61]). The outcome of depressed patients as a whole at 6 weeks or 6 months after the assessment did not significantly improve.

INTERPRETATION

Although well received, this in-practice programme, which was designed to convey the current consensus on best practice for the care of depression, did not deliver improvements in recognition of or recovery from depression.

Long-chain polyunsaturated fatty acids in children with attention-deficit hyperactivity disorder

Attention-deficit hyperactivity disorder (ADHD) is the diagnosis used to describe children who are inattentive, impulsive, and hyperactive. ADHD is a widespread condition that is of public health concern. In most children with ADHD the cause is unknown, but is thought to be biological and multifactorial. Several previous studies indicated that some physical symptoms reported in ADHD are similar to symptoms observed in essential fatty acid (EFA) deficiency in animals and humans deprived of EFAs. We reported previously that a subgroup of ADHD subjects reporting many symptoms indicative of EFA deficiency (L-ADHD) had significantly lower proportions of plasma arachidonic acid and docosahexaenoic acid than did ADHD subjects with few such symptoms or control subjects. In another study using contrast analysis of the plasma polar lipid data, subjects with lower compositions of total n-3 fatty acids had significantly more behavioral problems, temper tantrums, and learning, health, and sleep problems than did those with high proportions of n-3 fatty acids. The reasons for the lower proportions of long-chain polyunsaturated fatty acids (LCPUFAs) in these children are not clear; however, factors involving fatty acid intake, conversion of EFAs to LCPUFA products, and enhanced metabolism are discussed. The relation between LCPUFA status and the behavior problems that the children exhibited is also unclear. We are currently testing this relation in a double-blind, placebo-controlled intervention in a population of children with clinically diagnosed ADHD who exhibit symptoms of EFA deficiency.

Effect of spaceflight on single fiber function of triceps and biceps muscles in rhesus monkeys

Primates appeared to be a good model for investigating muscle contractile and biochemical properties, as well as EMG recordings. The purpose of our study was to examine the effects of microgravity on the contractile properties of the slow-type triceps and fast-type biceps muscles during the 14-day Bion 11 spaceflight.