Prognostic Value of BAP1 Protein Expression in Uveal Melanoma

The prognostic value of the traditional pathologic parameters that form part of the American Joint Committee on Cancer staging system and genetic classifications using monosomy chromosome 3 and structural alterations in chromosome 8 are well established and are part of the diagnostic workup of uveal melanoma (UM). However, it has not been fully clarified whether nuclear protein expression of the tumor suppressor gene BAP1 (nBAP1) by immunohistochemistry alone is as powerful a predictor of overall survival (OS) and/or disease-specific survival (DSS) as chromosome analysis. The protein expression of nBAP1 was evaluated in a retrospective cohort study of 308 consecutive patients treated by primary enucleation between January 1974 and December 2022. We correlated clinical, pathologic, and cytogenetic characteristics to identify the best prognostic indicators for OS and DSS. Loss of nBAP1 was detected in 144/308 (47%) of patients. Loss of nBAP1 expression was significantly associated with poor survival. In patients with disomy chromosome 3, nBAP1 negative is significantly associated with poorer OS but not DSS. We observed that older age (>63 years), presence of metastasis, and nBAP1 negative remained independent prognostic factors in multivariate analysis. nBAP1 protein expression proved to be a more reliable prognostic indicator for OS than the American Joint Committee on Cancer staging, M3 status, or The Cancer Genome Atlas classification in this cohort. This study provides support for accurate prognostication of UM patients in routine histology laboratories by immunohistochemistry for nBAP1 alone.

A Hybrid Intelligence (HI) System for Segmenting Rectoprostatic Spacer Gel and Key OARs on CT Images for Prostate Cancer Radiation Therapy Planning

PURPOSE/OBJECTIVE(S)

Our hybrid intelligence (HI) system, combining natural and artificial intelligence, is effective for auto-contouring H&N and thorax organs at risk (OARs) for radiation therapy (RT) planning with FDA 510(k) clearance. The purpose of this study is to test the HI system to segment a commercially available retroprostatic hyaluronic acid spacer gel (RSG) and pelvic OARs in planning CT images for prostate cancer RT.

HYPOTHESIS

HI can achieve clinically acceptable auto segmentation for tissue-equivalent RSG in this domain.

MATERIALS/METHODS

RSG is injected in the peri-rectal space in men with prostate cancer prior to RT to minimize rectal toxicity. 190 patients with prostate cancer were included in this post-hoc image analysis from a multi-center, prospective, randomized trial, with 136 in the spacer arm. The HI system has 3 steps: rough recognition from fuzzy model (FM) based automatic anatomy recognition (AAR-R), deep learning-based recognition (DL-R) refinement, and deep learning-based delineation (DL-D) to contour objects guided by the recognition results. FM encodes high level 3D anatomy knowledge of object shape and its relationship with other OARs; DL-R and DL-D focus on pixel-level details. The 190 studies are divided into disjoint training (100) and testing (90) subsets. 100 samples are used in DL-R and DL-D training, with 45 to build the FM for AAR-R. RSG and 4 other OARs (pelvic skin, prostate, bladder, rectum) are contoured. Location error (LE) is used to evaluate recognition; Dice coefficient (DC) and Hausdorff distance (HD) are employed to evaluate delineation. Acceptability scores (AS) (range 1-5, 1 for poor quality, 5 for best quality) from an observer study are recorded for HI-output and ground truth masks of RSG for assessing segmentation quality.

RESULTS

The HI system achieves highest DC (0.94±0.07) and lowest HD (1.96±1.61 mm) for bladder, for rectum and prostate similar DC (0.82±0.08) and HD (2.62±1.65mm), for RSG, the most challenging object, a good DC close to 0.7 (0.67±0.10) and excellent HD (2.66±1.44mm). AS for auto-segmentations (3.86±0.85) were significantly better than those for ground truth segmentations (3.45±1.00) (p = 0.02, paired t-test). Table 1 summarizes results.

CONCLUSION

The HI system achieves clinically acceptable segmentations for pelvic OARs and significantly better acceptability of segmentation of RSG compared to clinically performed ground truth segmentations. This has implications in improving efficiency and accuracy of CT-based RT planning in patients with prostate cancer.

Attitudes On The Role Of Nutrition In GP Training

Aim Nutrition is the leading cause of chronic disease globally, yet it is unknown how much nutritional education GP trainees receive. The aim is to identify GP trainee attitudes to nutrition and compare with the programme directors who deliver this training. Methods A multicentre online survey questionnaire of 542 GP trainees in Ireland and 63 programme directors over 2 weeks in September 2019. ANOVA analysis was used to determine if there was an agreement between programme directors and trainees. Results 13 GP training schemes participated, with 93 trainees (16%) and 9 (14%) programme directors answering the survey. There was consensus and agreement between trainees and programme directors for the following; it is the role of the GP to promote a healthy diet; there are barriers to optimal nutritional management; there would be interest in further education. ANOVA analysis found that there was agreement from directors and trainees in the assertion that nutritional education to date is not adequate. Discussion There is an agreement between GP trainees and their programme directors that the nutritional educational component of GP training is an unmet need. This study highlights the need for an improvement in nutritional education to maximise the management of chronic disease in Irish general practice.

Excited state intramolecular proton transfer in hydroxyanthraquinones: Toward predicting fading of organic red colorants in art

Compositionally similar organic red colorants in the anthraquinone family, whose photodegradation can cause irreversible color and stability changes, have long been used in works of art. Different organic reds, and their multiple chromophores, suffer degradation disparately. Understanding the details of these molecules' degradation therefore provides a window into their behavior in works of art and may assist the development of improved conservation methods. According to one proposed model of photodegradation dynamics, intramolecular proton transfer provides a kinetically favored decay pathway in some photoexcited chromophores, preventing degradation-promoting electron transfer (ET). To further test this model, we measured excited state lifetimes of substituted gas-phase anthraquinones using high-level theory to explain the experimental results. The data show a general structural trend: Anthraquinones with 1,4-OH substitution are long-lived and prone to damaging ET, while excited state intramolecular proton transfers promote efficient quenching for hydroxyanthraquinones that lack this motif.

The Safety of Discontinuation of Maintenance Therapy for Cytomegalovirus (CMV) Retinitis and Incidence of Immune Recovery Uveitis Following Potent Antiretroviral Therapy

BACKGROUND

Reconstitution of immune function during potent antiretroviral therapy can prompt discontinuation of maintenance cytomegalovirus (CMV) therapy but has also been associated with sight-threatening inflammatory conditions including immune recovery uveitis (IRU).

METHOD

Patients with inactive CMV retinitis and a CD4+ cell count above 100/mm3, receiving CMV therapy and stable combination antiretroviral therapy, were assigned to one of two groups based on willingness to discontinue CMV therapy.

RESULTS

Thirty-eight participants were enrolled: 28 discontinued anti-CMV therapy (Group 1) and 10 continued CMV treatment (Group 2). Median on-study follow-up was 16 months. One Group 1 participant who experienced an increase in plasma HIV viral load and a decline in CD4+ cell count developed confirmed progression of CMV retinitis. Progression or reactivation CMV retinitis was not observed among Group 2. IRU was present at study entry in 3 participants. Six participants in Group 1 and 3 participants in Group 2 developed IRU on-study. CMV viremia was not detected in any participants, and urinary shedding of CMV was intermittent.

CONCLUSION

Recurrence of CMV retinitis following discontinuation of anti-CMV therapy among patients with antiretroviral-induced increases in CD4+ cell count was rare. However, IRU was common in both those who maintained and discontinued anti-CMV therapy.

The external Ballard examination does not accurately assess the gestational age of infants born at home in a rural community of The Gambia

Background

Accurate assessment of gestational age at birth is critical to the identification of neonates at high risk. In resource‐poor settings, postnatal techniques are commonly used but may be difficult to apply and have not been well validated against ultrasound in community studies. The aim of this study was to evaluate postnatal assessment of gestational age in rural Africa using the external criteria of the Ballard examination against 1st/early 2nd‐trimester ultrasound and date of last menstrual period.

Method

In a sample of women from Kiang West, The Gambia (n = 80), the precision of gestational age estimates using the external Ballard examination was compared with those derived from 1st and early 2nd‐trimester ultrasound examination and date of last menstrual period.

Results

The incidence of preterm delivery was low at 2.5%. The external Ballard examination tended to underestimate gestational age by a mean (SD) of 15.6 (10.9) days compared with that derived from ultrasound and to underestimate by 15.4 (23.1) days compared with that derived from date of last menstrual period. The differences between the methods varied with gestation.

Conclusion

In this rural, community‐born population of infants, postnatal assessment of gestational age by external Ballard examination performed poorly compared with ultrasound and last menstrual period. No reliable gestational age could be derived from its estimate and it failed to detect a significant proportion of high‐risk infants. The development of an accurate but simple method of postnatally assessing gestational age specifically for use by health workers in rural Africa is required.

Low rate of CMV end-organ disease in HIV-infected patients despite low CD4+ cell counts and CMV viremia: results of ACTG protocol A5030

PURPOSE

To describe cytomegalovirus (CMV) end-organ disease (EOD) rate in AIDS patients with low CD4+ cell count despite HAART who were enrolled in a randomized, placebo-controlled trial of preemptive valganciclovir (VGCV) to prevent CMV EOD in those with CMV viremia.

METHODS

Subjects (N = 338) were HIV-infected with CD4+ count <100 cells/mm3, plasma HIV RNA >400 copies/mL, and on stable or no HAART. All underwent plasma CMV DNA PCR testing every 8 weeks (Step 1); those with detectable CMV DNA were randomized to VGCV or placebo (Step 2).

RESULTS

Plasma CMV DNA was detected in 68 (20%), of whom 4 developed CMV EOD. During Step 1, 53 died. Of the 47 who entered Step 2 (24 VGCV, 23 placebo), CMV EOD was diagnosed in 10 (4 VGCV, 6 placebo) and 15 died (7 VGCV, 8 placebo). Of those randomized to placebo, 14% were diagnosed with CMV EOD at 12 months.

CONCLUSIONS

We observed a lower CMV EOD rate among subjects receiving HAART than predicted based on published literature. However, mortality was high in this study. Our findings suggest that preemptive anti-CMV therapy in patients with persistently low CD4+ cell counts in the current treatment era may not be warranted given the low incidence of CMV EOD and high all-cause mortality observed in this study population.

The right to remain silent: a qualitative study of the medical and social ramifications of pregnancy disclosure for Gambian women

OBJECTIVES

Control of infectious diseases in developing countries often requires using drugs that are contraindicated during pregnancy. Avoiding inadvertent exposure to drugs involves women (a) recognising pregnancy early, (b) disclosing the pregnancy to health workers and (c) using medicines in an informed manner. We explored these factors to inform and improve the process by which health workers provide care and treatment to pregnant women.

DESIGN

Qualitative study.

SETTING

The Gambia.

POPULATION

Rural women and men.

METHODS

We conducted 41 interviews and 16 focus group discussions with women, adolescents, men and traditional birth attendants (TBAs).

MAIN OUTCOME MEASURE

Pregnancy disclosure.

RESULTS

Most women recognised early signs and symptoms of pregnancy and believed other people could easily do so. To avoid gossip, women hid their pregnancies and delayed antenatal care, even though husbands and TBAs insisted on attendance. Women acutely ill in early pregnancy hoped health workers would recognise pregnancy without explicit disclosure. Women said that they knew, and sought to avoid, some contraindicated drugs, but their knowledge was rudimentary. Health workers stressed the benefits, not the risks of prescribed drugs.

CONCLUSIONS

Despite public health and clinical benefits of preventing and treating pregnancy infections, women were ill informed and pressurised into taking drugs. These ethical issues should be more widely addressed.

Peripheral and visceral fat changes following a treatment switch to a non-thymidine analogue or a nucleoside-sparing regimen in HIV-infected subjects with peripheral lipoatrophy: results of ACTG A5110

BACKGROUND

Switching a thymidine analogue to a non-thymidine analogue or changing to a nucleoside-sparing regimen has been shown to partially reverse peripheral lipoatrophy. The current study evaluated both approaches.

METHODS

Subjects at 15 AIDS Clinical Trial Group sites receiving thymidine analogue stavudine- or zidovudine-containing regimens with plasma HIV RNA < or =500 copies/mL and lipoatrophy were prospectively randomized to: (i) switch the thymidine analogue to abacavir; (ii) discontinue all antiretrovirals and switch to lopinavir/ritonavir plus nevirapine (LPV/r+NVP); or (iii) delay switching for 24 weeks (ClinicalTrials.gov identifier: NCT00028314). Single-slice computer tomography of mid-thigh and abdominal fat and metabolic and virological/immunological parameters were measured at baseline and weeks 24 and 48.

RESULTS

Among the 101 patients enrolled, there were significant subcutaneous thigh fat and subcutaneous abdominal tissue (SAT) increases over time and decreases in visceral adipose tissue to total adipose tissue (VAT:TAT) ratios for both interventions, and a decrease in VAT for abacavir. CD4 increased in the LPV/r+NVP arm. LPV/r+NVP had a significantly shorter time to grade 3 or higher toxicity (P = 0.007), but discontinuation rates were similar. Glucose levels did not change, but insulin decreased in the LPV/r+NVP arm. Lipids tended to increase in the LPV/r+NVP arm.

CONCLUSIONS

Switching stavudine or zidovudine to a non-thymidine analogue or changing to a nucleoside reverse transcriptase inhibitor-sparing regimen is associated with qualitatively similar improvements in thigh fat, SAT and VAT:TAT ratio at 48 weeks. Abacavir also resulted in VAT reductions and LPV/r+NVP resulted in CD4 count increases.

Development of a screening tool for identifying women with menorrhagia for hemostatic evaluation

OBJECTIVE

A study was conducted to develop a short, easy to administer screening tool useful for stratifying women with unexplained menorrhagia for hemostatic testing for underlying bleeding disorders.

STUDY DESIGN

One hundred forty-six women with a physician diagnosis of menorrhagia underwent comprehensive hemostatic testing for the diagnosis of bleeding disorders, including von Willebrand disease, platelet dysfunction, and coagulation factor deficiencies. A 12 page questionnaire of bleeding symptoms was administered. Bleeding symptoms with high predictive values for laboratory hemostatic abnormalities were combined and used as single variables to calculate sensitivity, specificity, and positive and negative predictive values in order to develop a short screening tool to identify females for testing and evaluation.

RESULTS

A combination of 8 questions in 4 categories resulted in a sensitivity of 82% (95%CI 75-90) for bleeding disorders. Adding a pictorial blood assessment chart score > 100 increased the sensitivity of the screening tool to 95% (95%CI 91-99).

CONCLUSION

These results demonstrate the feasibility of a simple questionnaire based screening tool to identify females for testing and evaluation for bleeding disorders.

Nasopharyngeal aspiration for diagnosis of pulmonary tuberculosis

BACKGROUND

Confirmation of pulmonary tuberculosis (PTB) in young children is difficult as they seldom expectorate sputum.

AIM

To compare sputa obtained by nasopharyngeal aspiration and by sputum induction for staining and culture of Mycobacterium tuberculosis.

PATIENTS AND METHODS

Patients from Mulago Hospital, Kampala with symptoms suggestive of PTB were considered for inclusion in the study. Those with a positive tuberculin test and/or a chest radiograph compatible with tuberculosis were recruited. Infection with human immunodeficiency virus (HIV) was confirmed by duplicate enzyme-labelled immunosorbent assay or in children <15 months by polymerase chain reaction (PCR). Direct PCR was undertaken on 82 nasopharyngeal aspirates.

RESULTS

Of 438 patients referred, 94 were recruited over a period of 5 months. Median (range) age was 48 (4-144) months. Of 63 patients tested, 69.8% were infected with HIV. Paired and uncontaminated culture results were available for 88 patients and smear results for 94 patients. Nasopharyngeal aspirates were smear-positive in 8.5% and culture-positive in 23.9%. Induced sputa were smear-positive in 9.6% and culture positive in 21.6%. Overall, 10.6% were smear-positive, 25.5% were culture-positive and 26.6% had smear and/or culture confirmed tuberculosis. Direct PCR on nasopharyngeal aspirates had a sensitivity of 62% and specificity of 98% for confirmation of culture-positive tuberculosis.

CONCLUSIONS

Nasopharyngeal aspiration is a useful, safe and low-technology method for confirmation of PTB and, like sputum induction, can be undertaken in outpatient clinics.

Knowledge, attitudes, and behaviors of youths in the US hemophilia population: results of a national survey

OBJECTIVES

The National Hemophilia Foundation and the Centers for Disease Control and Prevention conducted a national survey focusing on knowledge about, attitudes toward, and behaviors associated with key prevention activities among youths with hemophilia and used the data gathered to design a health promotion campaign.

METHODS

A national, random sample of 459 patients was drawn from 20 hemophilia treatment centers and 8 hemophilia associations; 110 (24%) of the respondents were young people. A telephone questionnaire was used to measure knowledge, behaviors, and barriers to prevention.

RESULTS

Thirty-six percent of the youth respondents believed that joint disease cannot be prevented; 60% managed hemophilia by avoiding physical activity. Only 31% of the respondents treated bleeding episodes within 1 hour. Although hepatitis was a clear threat to this hemophilic cohort, 78% did now know transmission routes for hepatitis C, and 67% did not know transmission routes for hepatitis B.

CONCLUSIONS

Young people with chronic disorders need help understanding that they can prevent complications. We identified key messages for a hemophilia prevention campaign, including exercising to ensure healthy joints and treating bleeding episodes early and adequately.

Placental malaria and immunity to infant measles

The efficiency of transplacental transfer of measles specific antibody was assessed in relation to placental malaria. Infection at delivery was associated with a 30% decrease in expected cord measles antibody titres. Uninfected women who received anti-malarial drugs during pregnancy transmitted 30% more antibody than those who received no antimalarial drugs.

The association of anti-phospholipid antibodies with parity in placental malaria

Anti-phospholipid antibodies (aPL) are autoantibodies associated with both infections and the pathogenesis of certain pregnancy complications. In the latter, but not the former, aPL are dependent on a co-factor, beta(2) glycoprotein I (beta2GPI), which can also be used as an antigen for detection of such aPL in pregnancy. A cross-sectional study was carried out on serum samples from Kumasi, Ghana, to determine the occurrence and beta2GPI-dependence of aPL in placental malaria. Anti-cardiolipin, anti-phosphatidylserine and anti-beta2GPI enzyme-linked immunosorbent assays (ELISAs) were performed on sera from 103 HIV-non-infected gravid women. Placental malaria, both active and past infection, was diagnosed in 33/103 (32%) based on placental histology. In multiparae, beta2GPI-independent IgM antibodies to cardiolipin (P = 0.018) and phosphatidylserine (P = 0.009) were observed, which were most pronounced in past placental malaria infection. In primiparae, no association emerged between aPL and placental malaria. Trends for improved clinical parameters were identified in infected women with levels of anti-cardiolipin beyond the 99th multiple of the median for a healthy, non-malarious population. This study in placental malaria reports parity associations of beta2GPI-independent aPL profiles, and does not support a role for beta2GPI-dependent aPL. It is of significance in the context of the known parity differences in pregnancy malaria immunity.

The sick placenta-the role of malaria

The human placenta is an ideal site for the accumulation of Plasmodium falciparum malaria parasites, and as a consequence serious health problems arise for the mother and her baby. The pathogenesis of placental malaria is only partially understood, but it is clear that it leads to a distinct epidemiological pattern of malaria during pregnancy. The objectives of this review are: (1) To review recent data on the epidemiology of malaria in pregnancy, with emphasis on placental malaria; (2) to describe the pathological changes and immunological factors related to placental malaria; and (3) to discuss briefly the functional consequences of this infection for the mother and her baby. The review attempts to bring together local events at the maternal-fetal interface which encompass immunological and pathological processes which relate to the epidemiological pattern of malaria in pregnancy in areas of both high and low malaria transmission. An integrated understanding of the epidemiological, immunological and pathological processes must be achieved in order to understand how to control malaria in pregnancy. The yearly exposure of at least 50 million pregnancies to malaria infection makes it the commonest and most recurrent parasitic infection directly affecting the placenta. These statistics and our limited understanding of its pathogenesis suggest the research priorities on this subject.

Calcium channels triggering transmitter release in the rat medial superior olive

We used whole cell voltage clamp recordings from neurones in rat auditory brainstem slices to study the Ca(2+) channel types involved in triggering synaptic glutamate and glycine release in the medial superior olivary nucleus. Glutamate release from the anterior ventral cochlear (aVCN) bushy neurone synapse did not involve L-type Ca(2+) channels (alpha(1C-D); Ca(V)1.2-1.3), but was mediated with similar efficacies by both N-type (alpha(1B); Ca(V)2.2) and the P/Q-type Ca(2+) channels (alpha(1A); Ca(V)2.1). Glycine release from the medial nucleus of the trapezoid body (MNTB) synapse was mediated predominantly by P/Q-type Ca(2+) channels, but with a significant contribution from N-type Ca(2+) channels. Combined application of the P/Q- and N-type Ca(2+) channel toxins, omega-agatoxin IVA and omega-conotoxin GVIA, left a very small remnant of both the inhibitory and excitatory postsynaptic currents, probably reflecting a minimal contribution of R-type Ca(2+) channels (alpha(1E); Ca(V)2.3) to transmitter release. In contrast with aVCN bushy neurones, MNTB somata lacked both T- (alpha(1G-I); Ca(V)3.1-3.3) and L-type channels, but expressed a higher proportion of P/Q-type Ca(2+) channels.

Effect of sampling method on the representative recovery of microorganisms from the surfaces of aquacultured finfish

The objective of this study was to determine if a gentle rinse procedure was equivalent to the combination of excision and homogenization with a stomacher for the relative removal of various microorganisms from finfish fillets. Fillets of hybrid striped bass and rainbow trout were obtained from local markets and sampled using three methods: rinse (R), excision followed by homogenization in a stomacher (S), and homogenization of fillets following a rinse (RS). Microorganisms were enumerated on selective and nonselective media, and randomly selected colonies from aerobic plate counts were identified using MIDI Sherlock and BIOLOG microbial identification systems. Enrichments and selective media were used for the isolation of Listeria monocytogenes, Salmonella spp., and Yersinia enterocolitica. This study confirms previous reports that stomaching is superior to rinsing for enumerating total microbial populations from fish fillets. Rinsing was more effective for rainbow trout than for striped bass. Sampling method did not affect the relative magnitude of plate counts on media selective for aeromonads, pseudomonads, Shewanella, lactic acid bacteria, enterics, and gram-positive cocci. In the compositional analysis of random isolates, R recovered significantly lower fractions of aeromonads than did S or RS, but sampling method did not affect the percent recovery of lactic acid bacteria, pseudomonads, Shewanella, Moraxellaceae, or Cytophaga/Flavobacterium. However, observations suggest that with increased replication, differences among Moraxellaceae, Pseudomonas, and gram positives might be significant. Only one L. monocytogenes colony was isolated, and no Salmonella or Y. enterocolitica, so the effect of sampling method could not be determined for these organisms. Differences in predominant bacterial populations were seen between fish species.

Modulation of a presynaptic hyperpolarization-activated cationic current (I(h)) at an excitatory synaptic terminal in the rat auditory brainstem

1. A hyperpolarization-activated non-specific cation current, I(h), was examined in bushy cell bodies and their giant presynaptic terminals (calyx of Held). Whole-cell patch clamp recordings were made using an in vitro brain slice preparation of the cochlear nucleus and the superior olivary complex. The aim was to characterise I(h) in identified cell bodies and synaptic terminals, to examine modulation by presynaptic cAMP and to test for modulatory effects of I(h) activation on synaptic transmission. 2. Presynaptic I(h) was activated by hyperpolarizing voltage-steps, with half-activation (V(1/2)) at -94 mV. Activation time constants were voltage dependent, showing an e-fold acceleration for hyperpolarizations of -32 mV (time constant of 78 ms at -130 mV). The reversal potential of I(h) was -29 mV. It was blocked by external perfusion of 1 mM CsCl but was unaffected by BaCl(2). 3. Application of internal cAMP shifted the activation curve to more positive potentials, giving a V(1/2) of -74 mV; hence around half of the current was activated at resting membrane potentials. This shift in half-activation was mimicked by external perfusion of a membrane-permeant analogue, 8-bromo-cAMP. 4. The bushy cell body I(h) showed similar properties to those of the synaptic terminal; V(1/2) was -94 mV and the reversal potential was -33 mV. Somatic I(h) was blocked by CsCl (1 mM) and was partially sensitive to BaCl(2). Somatic I(h) current density increased with postnatal age from 5 to 16 days old, suggesting that I(h) is functionally relevant during maturation of the auditory pathway. 5. The function of I(h) in regulating presynaptic excitability is subtle. I(h) had little influence on EPSC amplitude at the calyx of Held, but may be associated with propagation of the action potential at branch points. Presynaptic I(h) shares properties with both HCN1 and HCN2 recombinant channel subunits, in that it gates relatively rapidly and is modulated by internal cAMP.

Differential diagnosis of shoulder injuries in sports

Shoulder injuries are common problems in all types of sports. There can be a good deal of variability in how symptoms are expressed from individual to individual, and part of the challenge in understanding the injury is being able to interpret the athlete's complaints as they relate to examination findings and the conditions that produce the symptoms. The history is particularly important because the sensitivity and specificity of many aspects of the examination are variable. A relaxed patient and a systematic evaluation is the best way to be thorough. Radiographs and even MRIs are frequently negative in soft tissue problems in the young athlete. This underscores the importance of a good examination. There may be some utility in using contrast-enhanced MRIs to look at labral pathologic conditions, cysts, or ganglions, but this information is certainly less useful than the patient's description of symptoms and the examiner's findings. With this awareness, we can manage these injuries with more confidence.

Impact of prophylaxis for Mycobacterium avium complex on bacterial infections in patients with advanced human immunodeficiency virus disease

The epidemiology and natural history of bacterial infections among ambulatory patients with advanced human immunodeficiency virus (HIV) disease has not been well described. In this prospective study, 394 subjects were enrolled and followed at 8-week intervals for a median of 21 months. During follow-up, 164 (42%) of 394 patients developed at least 1 bacterial infection. The most common infections were sinusitis, bacterial pneumonia, skin and soft tissue infection, and bronchitis. Serious bacterial infections (defined as bacterial pneumonia, bacteremia, or deep visceral abscess) were reported by 56 subjects (14%). Female sex, age of <40 years, and Karnofsky score of < or =80 were independent risk factors for bacterial infections. Prophylaxis with clarithromycin, trimethoprim and sulfamethoxazole, or both had significant protective effect. The occurrence of any confirmed bacterial infection was associated with a significantly increased risk of mortality. This study documents that bacterial infections are common among patients with advanced HIV disease, especially among women.

The adductor hallucis revisited

To evaluate anatomic variability in the insertion of the adductor hallucis into the lateral sesamoid and proximal phalanx of the great toe and to evaluate the extent of release of the adductor hallucis tendon performed through an incision in the dorsal first-web space, we recorded the angle of hallux valgus in 42 fresh-frozen specimens from human cadavers. An incision was made for a realignment of the soft tissues, dissecting down to the level of the intermetatarsal ligament. A loop of suture was placed around the identifiable adductor hallucis tendon through this incision along the lateral aspect of the lateral sesamoid. Then a plantar dissection removed all soft tissue to the level of the intermetatarsal ligament, adductor hallucis (transverse and oblique heads), lateral sesamoid, and lateral flexor hallucis brevis. The Insertion of these muscles into the proximal phalanx was evaluated. Specifically, we looked for separate slips of the adductor tendon inserting into the base of the proximal phalanx or separate insertions of the adductor tendon and the tendon of the flexor hallucis brevis muscle. In 33 of the 42 specimens, the entire adductor hallucis tendon had been isolated by the loop of suture through the incision in the dorsal first web. In eight of the remaining nine specimens, a small slip of the tendon (comprising less than 25% of its substance) had not been included. No specimen was found to have a separate slip of the adductor tendon inserting into the base of the proximal phalanx. Instead, all specimens were found to have only a conjoined insertion of fibers of the adductor hallucis and of the flexor hallucis brevis from the lateral sesamoid into the base of the proximal phalanx. We did not identify a separate tendon-insertion into the proximal phalanx in any specimen. Therefore, great caution should be exercised in releasing an isolated insertion of the adductor tendon from the base of the proximal phalanx of the great toe since it may actually represent the conjoined insertion of the lateral flexor hallucis brevis tendon and the adductor tendon. We found that by simply releasing the adductor tendon from its insertion along the lateral aspect of the sesamoid, accomplished through an incision in the dorsal first web, that an adequate release was achieved in most specimens.

Characterisation of inhibitory and excitatory postsynaptic currents of the rat medial superior olive

The medial superior olive (MSO) is part of the binaural auditory pathway, receiving excitatory projections from both cochlear nuclei and an inhibitory input from the ipsilateral medial nucleus of the trapezoid body (MNTB). We characterised the excitatory and inhibitory synaptic currents of MSO neurones in 3- to 14-day-old rats using whole-cell patch-clamp methods in a brain slice preparation.A dual component EPSC was mediated by AMPA and NMDA receptors. The AMPA receptor-mediated EPSC decayed with a time constant of 1.99+/-0.16 ms (n = 8). Following blockade of glutamate receptors, a monosynaptic strychnine-sensitive response was evoked on stimulation of the MNTB, indicative of a glycine receptor-mediated IPSC. GABAA receptors contributed to IPSCs in rats under 6 days old (bicuculline blocked 30% of the IPSC). In older rats little or no bicuculline-sensitive component was detectable, except in the presence of flunitrazepam. These glycinergic IPSCs showed a reversal potential that varied with changes in [Cl-]i, as predicted by the Nernst equation. The IPSC exhibited two developmentally relevant changes. (i) At around postnatal day 6, the GABAA receptor-mediated component declined, leaving a predominant glycine-mediated IPSC. The isolated glycinergic IPSC decayed with time constants of 7.8+/-0.3 and 38.3+/-1.7 ms, with the slower component contributing 7.8+/-0.6% of the peak amplitude (n = 121, 3-11 days old, -70 mV, 25 deg C). (ii) After day 11 the IPSC fast decay accelerated to 3.9+/-0.3 ms (n = 12) and the magnitude of the slow component declined to less than 1%. Spontaneous miniature glycinergic IPSCs (mIPSCs) were variable in amplitude and were of large conductance (1.83+/-0.19 nS, n = 8). The amplitude was unchanged on lowering [Ca2+]o. The time course of evoked and spontaneous miniature glycinergic IPSCs were compared. The 10-90% rise times were 0.7 and 0.6 ms, respectively. The evoked IPSC decayed with a fast time constant of 7.2+/-0.7 ms, while the mIPSC decayed with a fast time constant of 5.3+/-0.4 ms in the same seven cells.The glycinergic IPSC decay was voltage dependent with an e-fold change over 118 mV. The temperature dependence of the IPSC decay indicated a Q10 value of 2. Picrotoxin and cyanotriphenylborate had little or no effect on IPSCs from 6- to 14-day-old animals, implying homomeric channels are rare. We conclude that the MSO receives excitatory inputs mediated by AMPA and NMDA receptors and a strong glycinergic IPSC which has a significant contribution from GABAA receptors in neonatal rats. Functionally, the IPSC could increase membrane conductance during the decay of binaural glutamatergic EPSCs, thus refining coincidence detection and interaural timing differences.

Viability and functional activity of cryopreserved mononuclear cells

Factors that influence viability and function of cryopreserved peripheral blood mononuclear cells (PBMC) were identified on 54 samples from 27 AIDS Clinical Trial Units. PBMC viability ranged from 1 to 96% with a median of 70%, was higher in laboratories with experienced staff, and was not significantly associated with CD4 cell number. Function of cryopreserved PBMC, measured by lymphocyte proliferation, was associated with viability. Preparations with viability greater than or equal to 70% had consistent proliferative responses and were suitable for functional analyses.

Visceral adipose tissue and markers of the insulin resistance syndrome in obese black and white teenagers

OBJECTIVE

To determine the relationships between visceral and general adiposity, cardiovascular fitness, and markers of the insulin resistance syndrome in obese black and white teenagers.

RESEARCH METHODS AND PROCEDURES

Cross-sectional survey of 81 obese 13- to 16-year-old youths. Visceral adipose tissue was measured with magnetic resonance imaging, and percentage body fat was measured with dual-energy X-ray absorptiometry. Cardiovascular fitness was assessed with a submaximal treadmill test. Fasting blood samples were analyzed for lipids/lipoproteins and insulin. Resting blood pressure was obtained using an automated cuff.

RESULTS

Visceral adipose tissue was significantly correlated with unfavorable levels of: triacylglycerol (r = 0.27, p < 0.05), total cholesterol (r = 0.27, p < 0.05), high-density lipoprotein cholesterol (r = -0.26, p < 0.05), the ratio of total cholesterol/high-density lipoprotein cholesterol (r = 0.42, p < 0.01), low-density lipoprotein cholesterol (r = 0.27, p < 0.05), apolipoprotein B (r = 0.38, p < 0.01), and systolic blood pressure (r = 0.30, p < 0.01). Multiple regression analyses revealed that visceral adipose tissue was more powerful than percentage body fat for explaining variance in lipoproteins (e.g., for the ratio of total cholesterol/high-density lipoprotein cholesterol, r2 = 0.13, p < 0.01, and for systolic blood pressure, r2 = 0.07, p < 0.05). Ethnicity was the most powerful of the demographic predictors for blood lipids (r2 = 0.15 for triacylglycerol with lower levels in blacks; r2 = 0.10 for high-density lipoprotein cholesterol with higher levels in blacks; r2 = 0.06 for the ratio of total cholesterol/high-density lipoprotein cholesterol with lower levels in blacks). Cardiovascular fitness was not retained as a significant predictor of markers of the insulin resistance syndrome.

DISCUSSION

Some of the deleterious relationships between visceral adiposity and markers for the insulin resistance syndrome seen in adults were already present in these obese young people.

Recurrent haematomas of the thigh: a case of von Willebrand's disease presenting to a sports clinic

Von Willebrand's disease is a relatively common mild form of haemophilia. It should be suspected in assessing sports injuries when excessive bleeding occurs in response to relatively mild trauma. Those with the disease should remain active but avoid contact sports. They should not take aspirin or non-steroidal anti-inflammatory drugs, which may exacerbate bleeding, and should be given supportive treatment to cover dental extraction, surgery, or significant bleeding episodes.

Heart rate variability in obese children: relations to total body and visceral adiposity, and changes with physical training and detraining

OBJECTIVE

Heart rate variability provides non-invasive information about cardiac parasympathetic activity (PSA). We determined in obese children: (1) relations of baseline PSA to body composition and hemodynamics; (2) effects of physical training (PT) and cessation of PT; and (3) which factors explained individual differences in responsivity of PSA to the PT.

RESEARCH METHODS AND PROCEDURES

The root mean square of successive differences (RMSSD) was the index of PSA. Obese children (n = 79) were randomly assigned to groups that participated in PT during the first or second 4-month periods of the study.

RESULTS

Baseline RMSSD was significantly (p<0.05) associated with lower levels of: fat mass, fat-free mass, subcutaneous abdominal adipose tissue, resting heart rate (HR), resting systolic blood pressure, and exercise HR. Stepwise multiple regression produced a final model (R2 = 0.36) that included only resting HR. The analysis of changes over the three time points of the study found a significant (p = 0.026) time by group interaction, such that RMSSD increased during periods of PT and decreased following cessation of PT. Greater individual increases in response to the PT (p<0.05) were seen in those who had lower pre-PT RMSSD levels, showed the greatest decreases in resting HR, and increased most in vigorous physical activity. The final regression model retained only the change in resting HR as a significant predictor of the changes in the RMSSD (R2 = 0.23).

DISCUSSION

Regular exercise that improved fitness and body composition had a favorable effect on PSA in obese children.

Effects of exercise training and its cessation on components of the insulin resistance syndrome in obese children

OBJECTIVE

To determine the effect of exercise training (ET) on components of the insulin resistance syndrome (IRS) in obese children.

DESIGN

Randomized, modified cross-over study, with subjects assigned to one of two conditions: (1) 4 months of ET followed by 4 months of no-ET; or (2) 4 months of no-ET followed by 4 months of ET. Measurements were made at three time points: 0, 4 and 8 months.

SUBJECTS

79 obese, but otherwise healthy children (age: 7-11 y, percent fat (%fat) 27-61%).

MEASUREMENTS

Plasma lipid and lipoprotein concentrations, plasma insulin and glucose concentrations; %fat; submaximal heart rate (HR) as an index of fitness. EXERCISE TRAINING: ET was offered 5 d/week 40 min/d. For the 73 children who completed 4 months of ET, the mean attendance was 80% (that is, 4 d/week) and the average HR during ET was 157 bpm.

RESULTS

Significant (P < 0.05) group x time interactions were found for plasma triglyceride (TG) and insulin concentrations and %fat. The average change for both groups, from just before ET to just after the 4 month ET was -0.24 mmol.l-1 for TG, -25.4 pmol.l-1 for insulin and -1.6 units for %fat. When Group 1 ceased ET, over the following 4 month period the average change for insulin was +26.6 pmol.l-1 and for %fat +1.3 units.

CONCLUSION

Some components (plasma TG, insulin, %fat) of the IRS are improved as a result of 4 months of ET in obese children. However, the benefits of ET are lost when obese children become less active.

Effects of physical training and its cessation on the hemostatic system of obese children

BACKGROUND

Physical training can improve hemostatic function in adults, thereby reducing heart disease risk, but no information is available in children on whether physical training can enhance hemostatic function.

OBJECTIVE

The purpose of this investigation was to examine the effects of a physical training program on hemostatic variables in a biethnic group of obese children.

DESIGN

Children were randomly assigned to 2 groups. Group 1 participated in physical training for 4 mo and then ceased physical training for 4 mo, whereas group 2 did no physical training for the first 4 mo and then participated in physical training for 4 mo. Plasma hemostatic variables [fibrinogen, plasminogen activator inhibitor 1 (PAI-1), and D-dimer) were measured at months 0, 4, and 8.

RESULTS

Analyses of variance revealed no significant group-by-time interactions for the hemostatic variables. When data from both groups were combined there was a significant decrease in D-dimer after 4 mo of physical training (P < 0.05). Factors explaining individual differences in responsiveness to the physical training revealed that individuals with greater percentage fat before physical training showed greater reductions in fibrinogen and D-dimer, and that blacks showed greater reductions in D-dimer than whites (P < 0.05). Stepwise multiple linear regression showed that only higher prephysical training concentrations of fibrinogen, PAI-1, and D-dimer explained significant proportions of the variation in changes in these variables.

CONCLUSIONS

In obese children, 4-mo periods of physical training did not lead to significant changes in hemostatic variables. Children with greater adiposity and concentrations of hemostatic factors before physical training showed greater reductions in hemostatic variables after physical training than did children with lesser values.

Correlates of individual differences in body-composition changes resulting from physical training in obese children

BACKGROUND

No studies have been reported in children that assess correlates of body-composition changes in response to a physical training intervention.

OBJECTIVE

The hypothesis studied was that variation in diet and physical activity would explain a significant portion of the interindividual variation in the response of body composition to physical training.

DESIGN

The participants were 71 obese children aged 7-11 y (22 boys, 49 girls; 31 whites, 40 blacks). Body composition was measured by dual-energy X-ray absorptiometry, physical activity by a 7-d recall interview, and diet by two, 2-d recalls. The children underwent 4 mo of physical training.

RESULTS

The mean attendance was 4 d/wk, the mean (+/-SD) heart rate for the 40-min sessions was 157 +/- 7 beats/min, and the mean energy expenditure was 946 +/- 201 kJ/session. On average, the percentage body fat decreased significantly in the total group, and total mass, fat-free soft tissue, bone mineral content, and bone mineral density increased, but there was a good deal of individual variability. Multiple regression models indicated that in general, more frequent attendance, being a boy, lower energy intake, and more vigorous activity were associated with healthier body-composition changes with physical training. Ethnicity was not retained as a correlate of the change of any component of body composition.

CONCLUSIONS

In obese children, age, vigorous activity, diet, and baseline percentage body fat together accounted for 25% of the variance in the change in percentage body fat with physical training.

Plasma leptin concentrations in obese children: changes during 4-mo periods with and without physical training

BACKGROUND

Little is known about the effects of physical training on plasma leptin concentrations in children.

OBJECTIVE

We sought to determine the effects of 4-mo periods with and without physical training on leptin in obese children and to explore the determinants of leptin at baseline and in response to physical training.

DESIGN

Participants were 34 obese 7-11-y-old children randomly assigned to engage in physical training during either the first or second 4 mo of the 8-mo study.

RESULTS

Total body composition, visceral adiposity, and insulin were all positively correlated with leptin at baseline (P < or = 0.05); however, only fat mass was retained in the final stepwise regression (P = 0.0001, R2 = 0.57). Leptin decreased during the 4-mo periods of physical training and increased in the 4 mo after cessation of physical training (P < 0.001 for the time by group interaction). Decreases in leptin were greatest in children with higher pretraining leptin concentrations, those whose total mass increased least, and those whose insulin concentrations decreased most (P < or = 0.05); only pretraining leptin concentration (P = 0.009) and change in total mass (P = 0.0002) were retained in the final regression (R2 = 0.53).

CONCLUSIONS

In obese children, leptin concentration decreased during 4 mo of physical training and increased during a subsequent 4-mo period without physical training, fat mass was highly correlated with baseline leptin, and greater reductions in leptin during 4 mo of physical training were seen in children with higher pretraining leptin and in those whose total mass increased least.