Immediate effect of hallux valgus surgery on the biomechanical behavior of the first ray

BACKGROUND

The surgical treatment of hallux valgus (HV) deformity has been the subject of countless publications but few focus on the altered windlass mechanism or analyze the biomechanical behavior immediately after surgery.

METHODS

Patients treated for HV between January and March 2023 were included. The surgery consisted of a L-reverse first metatarsal osteotomy. To analyze the windlass mechanism we record two different measurements; the isolated first metatarsophalangeal joint (MTPJ) dorsiflexion angle (IDA) and dynamic plantarization of the first metatarsal head when performing first MTPJ dorsiflexion imprinting a mark on a modeling foam.

RESULTS

A total of 30 patients diagnosed with symptomatic HV were included. In all patients, a change in the IDA angle was evident, being overall statistically significant. About modeling foam imprinted mark, all measurements, in all planes of space, had a clear tendency to increase, which turned out to be statistically significant (p < 0.001).

CONCLUSIONS

An altered windlass mechanism may be successfully recovered immediately after hallux valgus deformity surgery. This could be evinced by an indirect measurement analyzing the imprint of the head of the first metatarsal in a modeling foam and the IDA.

LEVELS OF EVIDENCE II

None.

Midbrain and pons MRI shape analysis and its clinical and CSF correlates in degenerative parkinsonisms: a pilot study

OBJECTIVES

To conduct brainstem MRI shape analysis across neurodegenerative parkinsonisms and control subjects (CS), along with its association with clinical and cerebrospinal fluid (CSF) correlates.

METHODOLOGY

We collected demographic and clinical variables, performed planimetric and shape MRI analyses, and determined CSF neurofilament-light chain (NfL) levels in 84 participants: 11 CS, 12 with Parkinson's disease (PD), 26 with multiple system atrophy (MSA), 21 with progressive supranuclear palsy (PSP), and 14 with corticobasal degeneration (CBD).

RESULTS

MSA featured the most extensive and significant brainstem shape narrowing (that is, atrophy), mostly in the pons. CBD presented local atrophy in several small areas in the pons and midbrain compared to PD and CS. PSP presented local atrophy in small areas in the posterior and upper midbrain as well as the rostral pons compared to MSA. Our findings of planimetric MRI measurements and CSF NfL levels replicated those from previous literature. Brainstem shape atrophy correlated with worse motor state in all parkinsonisms and with higher NfL levels in MSA, PSP, and PD.

CONCLUSION

Atypical parkinsonisms present different brainstem shape patterns which correlate with clinical severity and neuronal degeneration. In MSA, shape analysis could be further explored as a potential diagnostic biomarker. By contrast, shape analysis appears to have a rather limited discriminant value in PSP.

KEY POINTS

• Atypical parkinsonisms present different brainstem shape patterns. • Shape patterns correlate with clinical severity and neuronal degeneration. • In MSA, shape analysis could be further explored as a potential diagnostic biomarker.

Availability and use of rapid diagnostic tests for the management of acute childhood infections in Europe: A cross-sectional survey of paediatricians

BACKGROUND

Point-of-care-tests (POCTs) have been advocated to optimise care in patients with infections but their actual use varies. This study aimed to estimate the variability in the adoption of current POCTs by paediatricians across Europe, and to explore the determinants of variability.

METHODS AND FINDINGS

A cross-sectional survey was conducted of hospital and primary care paediatricians, recruited through professional networks. Questions focused on the availability and use of currently available POCTs. Data were analysed descriptively and using Median Odds Ratio (MOR) to measure variation between countries. Multilevel regression modelling using changes in the area under the receiver operating characteristic curve of models were used to assess the contribution of individual or workplace versus country level factors, to the observed variation. The commonest POCT was urine dipsticks (UD) which were available to >80% of primary care and hospital paediatricians in 68% (13/19) and 79% (23/29) countries, respectively. Availability of all POCTs varied between countries. In primary care, the country (MOR) varied from 1.61 (95%CI: 1.04-2.58) for lactate to 7.28 (95%CI: 3.04-24.35) for UD. In hospitals, the country MOR varied from 1.37 (95%CI:1.04-1.80) for lactate to 11.93 (95%CI:3.35-72.23) for UD. Most paediatricians in primary care (69%, 795/1154) and hospital (81%, 962/1188) would use a diagnostic test in the case scenario of an infant with undifferentiated fever. Multilevel regression modelling showed that the country of work was more important in predicting both the availability and use of POCTs than individual or workplace characteristics.

CONCLUSION

There is substantial variability in the adoption of POCTs for the management of acute infections in children across Europe. To inform future implementation of both existing and innovative tests, further research is needed to understand what drives the variation between countries, the needs of frontline clinicians, and the role of diagnostic tests in the management of acute childhood infections.

Considerations for Radiation Safety Professionals to Prepare and Respond to the Next Pandemic

ABSTRACT

The Health Physics Society's stated mission is "excellence in the science and practice of radiation safety." Why, then, should we discuss disease outbreaks, epidemics, and pandemics with radiation safety professionals? The answer is simple: all workers are impacted by infectious diseases-and, as safety professionals, we will inevitably be called upon to prepare for and respond to these events. The COVID-19 pandemic has disrupted every facet of life, including home, school, work, and leisure. Moreover, virtually all radiation safety professionals have been impacted by the pandemic either personally, academically, or professionally. Even if radiation safety professionals were not involved directly with COVID-19 response, they were impacted by school closures, remote schooling and work, testing regimes, temperature screenings, vaccination programs, and so forth. However, many radiation safety professionals have been intimately involved in COVID-19 response through activities such as the deployment of personal protective equipment, directional airflow verification for isolation areas, disinfection and decontamination efforts, the design and layout of testing and vaccine centers, and in many other ways. Yet, it is likely that many radiation safety professionals have not received formal training in epidemiology, disease control, or other related topics, and thus may not be attuned to the key aspects to consider when the next pandemic emerges-and it will.

Applying the Ottawa Ankle Rules in a Pediatric Emergency Department

OBJECTIVES

Ankle and midfoot injuries constitute one of the most frequent reasons to visit the pediatric emergency department (ED). The aims of the study were (1) to determine the feasibility of the Ottawa Ankle Rules (OARs) in a pediatric ED and its reliability to safely manage ankle and midfoot injuries and (2) to verify the impact in reducing the number of radiographs, healthcare costs, and time spent in the ED.

METHODS

The prospective study enrolled 90 patients for the control group and 94 for the case group. For the control group, the standard of practice was registered. In the case group, before beginning enrolment, an instruction of how to apply the OARs were given to all clinicians. After that, OARs were applied according to patient complaints. A follow-up call was made for both groups.

RESULTS

The mean age of the control group was 11.9 years (standard deviation, 3.267 years), whereas in the case group was 11.3 years (standard deviation, 3.533 years). Demographic and injury characteristics were similar in both groups. A significant statistical difference was verified in the number of radiographs (P = 0.001) with a reduction of 16.7% in the case group. Patients who did not perform radiography, in the case group, spent at least 1 hour less than the ones who did. The OARs have shown a sensitivity of 100% (95% confidence interval, 39.76-100.00) and specificity of 23.33% (95% CI, 15.06-33.43) with a negative predictive value of 100%.

CONCLUSIONS

The OARs are an important clinical instrument with a high sensitivity and negative predictive value, which allows clinicians to avoid unnecessary exposure to radiation without missing clinically relevant fractures.

The Impact of Focused Cardiac Ultrasound Performed by Pediatric Intensivists: A Prospective Study

OBJECTIVES

Focused cardiac ultrasound is an echocardiographic method used by medical intensivists for fast and reliable hemodynamic assessment. Prospective studies and guidelines have defined its role in adult critical care. Data regarding its use in pediatric critical care are scarce. This is the first prospective study that aims to evaluate its impact in this setting.

METHODS

This is a single-center prospective study performed in a tertiary referral hospital pediatric intensive care unit (PICU). For a period of 6 months, when performing an echocardiogram, pediatric intensivists filled out a questionnaire that included the patient's clinical data and indication for the examination. The intensivists had to record both the clinical impression regarding that indication and therapeutic plan before and after the echocardiogram. All the patients with an echocardiogram performed by the pediatric intensive care unit medical staff were included.

RESULTS

There were 80 echocardiograms performed on 35 patients during the study period. The most common patient diagnostic groups were respiratory infections (38%, n = 30) and septic shock (21%, n = 17). The main indication for the examination was assessment of intravascular volume status and left ventricular systolic function. After the echocardiogram, the clinical impression was maintained in 49% (n = 39) and changed in 44% (n = 35). There were new findings unrelated to the initial evaluation in 7% (n = 6). The planned treatment was maintained in 55% (n = 44) and changed in 45% (n = 36).

CONCLUSIONS

The echocardiogram changed the clinical impression and therapeutic plan in almost half of the patients. These data show the value of focused cardiac ultrasound as a diagnostic and hemodynamic monitoring tool in pediatric intensive care and emphasize the importance of a rigorous training program.

COVID-19 Era Effect on Pandemic and Post-pandemic Pediatric Telemedicine Use: A Survey of the European Academy of Pediatrics Research in Ambulatory Settings Network

Background: During the COVID-19 pandemic, telemedicine use has increased within community pediatrics. This trend runs counter to reluctance to adaptation of the new mode of healthcare that existed prior to the pandemic. Little is known about what we can expect after the pandemic: if physicians will opt for telemedicine modalities and if tele-pediatrics will continue to be a significant mode of community pediatric care. Objective: The goal of this study was to survey primary pediatric care providers as to their experiences and clinical decision making with telemedicine modalities prior to and during the COVID-19 pandemic, as well as their projected use after the pandemic ends. Material and methods: Using the EAPRASnet database we surveyed pediatricians throughout Europe, using a web-based questionnaire. The survey was performed during the COVID-19 pandemic (June-July 2020), assessed telemedicine use for several modalities, prior to and during the pandemic as well as predicted use after the pandemic will have resolved. Participants were also surveyed regarding clinical decision making in two hypothetical clinical scenarios managed by telemedicine. Results: A total of 710 physicians participated, 76% were pediatricians. The percentage of respondents who reported daily use for at least 50% of all encounters via telemedicine modalities increased during the pandemic: phone calls (4% prior to the pandemic to 52% during the pandemic), emails (2-9%), text messages (1-6%), social media (3-11%), cell-phone pictures/video (1-9%), and video conferencing (1-7%) (p < 0.005). The predicted post-pandemic use of these modalities partially declined to 19, 4, 3, 6, 9, and 4%, respectively (p < 0.005), yet demonstrating a prospectively sustained use of pictures/videos after the pandemic. Reported high likelihood of remotely treating suspected pneumonia and acute otitis media with antibiotics decreased from 8 to 16% during the pandemic to an assumed 2 and 4% after the pandemic, respectively (p < 0.005). Conclusions: This study demonstrates an increased utilization of telemedicine by pediatric providers during the COVID-19 pandemic, as well as a partially sustained effect that will promote telemedicine use as part of a hybrid care provision after the pandemic will have resolved.

Monthly changes in serum levels of S100B protein as a predictor of metastasis development in high-risk melanoma patients

BACKGROUND

The role of S100B protein in detecting early melanoma relapses is controversial, since most metastasis occur within normal values of S100B.

OBJECTIVE

The aim of this study was to assess the performance of S100B in detecting early disease progression in high-risk melanoma patients.

METHODS

Retrospective cohort study including patients with an initial diagnosis of stage IIB, IIC and III melanoma between January 2003 and July 2013. All patients were followed up in accordance with an intensive protocol based on imaging studies and serum S100B levels every 3-6 months. We compared two methods to evaluate changes in S100B. The classic method referring to a single determination of S100B above the cut-off level at the time of metastasis, which was evaluated in all patients. And a new method based on monthly changes of S100, which was used in the setting of patients with S100B levels within the normal range.

RESULTS

Overall, 289 of patients were followed up for 44 months (IQR 17-73) and 45% developed metastases. During the study period, 129 patients relapsed of which 46 (35.7%) present elevated values of S100B at the time of relapse. The classic method had a sensitivity and specificity of S100B protein of 35.7% and 92.5%, respectively. Furthermore, for the patients that relapsed with normal values of S100B, the new method was applied and showed a sensitivity and specificity of 41.1% and 92.4%, respectively, allowing to detect additional relapses that were missing by the classic method.

CONCLUSION

During follow-up of high-risk melanoma patients, rising serum S100B values within the normal range can be an important clue to disease progression.

Association between completed suicide and bipolar disorder: A systematic review of the literature

BACKGROUND

Completed suicide is a major cause of death in bipolar disorder (BD) patients.

OBJECTIVE

The aim of this paper is to provide an overall review of the existing literature of completed suicide in BD patients, including clinical and genetic data DATA SOURCES: We performed a systematic review of English and non-English articles published on MEDLINE/PubMed, PsycInfo and Cochrane database (1970-2017). Additional studies were identified by contacting clinical experts, searching bibliographies, major textbooks and website of World Health Organization. Initially we did a broad search for the association of bipolar disorder and suicide and we were narrowing the search in terms included "bipolar disorder" and "completed suicide".

STUDY SELECTION

Inclusion criteria were articles about completed suicide in patients with BD. Articles exclusively focusing on suicide attempts and suicidal behaviour have been excluded. We used PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) consensus for drafting this systematic review.

RESULTS

The initial search generated 2806 articles and a total of 61 meeting our inclusion criteria. We reviewed epidemiological data, genetic factors, risk factors and treatment of completed suicide in BD. Suicide rates in BD vary between studies but our analyses show that they are approximately 20-30-fold greater than in general population. The highest risk of successful suicide was observed in BD-II subjects. The heritability of completed suicide is about 40% and some genes related to major neurotransmitter systems have been associated with suicide. Lithium is the only treatment that has shown anti-suicide potential.

LIMITATIONS

The most important limitation of the present review is the limited existing literature on completed suicide in BD.

CONCLUSIONS

BD patients are at high risk for suicide. It is possible to identify some factors related to completed suicide, such as early onset, family history of suicide among first-degree relatives, previous attempted suicides, comorbidities and treatment. However it is necessary to promote research on this serious health problem.

OIL BEHAVIOUR AND THE RESPONSE TO A SUNKEN OIL SPILL OF SLURRY IN QUINTERO BAY, CHILE

Slurry oils are one of the few groups of oils that have a density greater than full salinity seawater. Slurry spills at sea are rare, but when they do occur, the response can be difficult, with low final recovery rates. Oil spill response planning and recovery techniques have been refined over many years and the research and development of most methods has been underpinned by the principle that oil floats on water. This recent case study provides an example of the behavior of a slurry spill and the subsequent response operations. A leak of an API gravity 4° slurry occurred from a submarine pipeline in Quintero Bay, Chile, on 14th May 2016. The oil sank to the adjacent sea bed and covered an area of approximately 10,000 m2 in water depths of 18–22 m. The initial response involved over 20 dry-suit divers with surface air to recover the oil with vacuum hoses. These were then supplemented by four diver-operated vacuum dredges. Fortunately weak bottom currents did not redistribute the oil; nevertheless “sea bed booms” were deployed around the perimeter to prevent migration. These “booms” were initially a screen mesh that was later supplemented by sturdier metal frame screens deployed around the zone of the sunken oil in a zigzag configuration. Baseline benthic sediment samples were collected from the adjacent unaffected area and subsequently from the treatment area after completion of operations. A benthic SCUBA SCAT survey using a track-line positioning system was conducted to systematically document the distribution of the oil and post-treatment systematic ROV survey ensured that the end-point oiling conditions had been achieved.

Hydrogel-Based Engineering of Beige Adipose Tissue

Brown and beige adipose tissues have a significant capacity for energy expenditure that may be exploited as a treatment for obesity and metabolic disease. However, the limited volumes of these tissues in adults hinders realization of this potential. Engineering beige adipose tissue may provide an alternative source of this tissue. In this paper we describe the preparation of poly(ethylene glycol) (PEGDA) hydrogels with mechanical properties similar to native adipose tissue. Adipose derived stem cells (ASC) were cultured in hydrogels without adhesive sequences or degradable monomers. Cells were able to differentiate, independent of scaffold properties and were maintained as a viable and functioning adipose tissue mass. The cells expressed their own basement membrane proteins consistent with the composition of adipose tissue. The ASCs could be induced to express uncoupling protein-1 (UCP-1) and cIDEA, makers of beige adipocytes with expression level varying with hydrogel stiffness. This hydrogel-based culture system serves as a first step in engineering beige adipose tissue.

Results of induction chemotherapy in children older than 18 months with stage-4 neuroblastoma treated with an adaptive-to-response modified N7 protocol (mN7)

PURPOSE

We report the response rate in children older than 18 months with stage 4 Neuroblastoma, using a modified dose-intensive, response-adaptive, induction mN7 protocol.

METHODS

From 2005 to 2012, 24 patients were treated with the mN7 protocol. Phase 1 included five MSKCC N7 cycles and surgery and two high-dose cyclophosphamide-topotecan (HD-CT) cycles for those who did not achieve complete remission (CR) and negative bone marrow (BM) minimal residual disease (MRD) status (CR+MRD-). Phase 2 consisted of myeloablative doses of topotecan, thiotepa and carboplatin plus hyperfractionated RT. Phase 3 included isotretinoin and 3F8 immunotherapy plus GM-CSF. BM MRD was monitored using GD2 synthase, PHOX2B and cyclin D1 mRNAs.

RESULTS

After 3 cycles, all patients showed BM complete histological clearance and 6 (25 %) were MRD-. Twenty of 21 s-look surgeries achieved macroscopic complete resection. After 5 cycles and surgery, (123)I-MIBG scan was negative in 15 (62.5 %) cases, BM disease by histology was negative in 23 (96 %) and 10 (42 %) patients were MRD-. Twelve (50 %) pts were in CR, 2 in very good partial response (VGPR), 9 partial response (PR) and one had progressive disease. With 2 HD-CT extra cycles, 17 (71 %) pts achieved CR+MRD- status moving to phase 2. Overall and event-free survival at 3 years for the 17 patients who achieved CR+MRD- is 65 and 53 %, respectively, median follow-up 47 months. Seven (29 %) patients never achieved CR+MRD-. Univariate Cox regression analysis shows CR+MRD- status after mN7 induction as the only statistically significant prognostic factor to predict overall survival.

CONCLUSIONS

mN7 induction regimen produced a CR+MRD- rate of 71 %. CR+MRD- status following induction was the only predictive marker of long-term survival.

[Analysis of the failures of a cemented constrained liner model in patients with a high dislocation risk]

OBJECTIVE

To evaluate the short-term results of an ultra high molecular weight polyethylene retentive cup in patients at high risk of dislocation, either primary or revision surgery.

MATERIAL AND METHOD

Retrospective review of 38 cases in order to determine the rate of survival and failure analysis of a constrained cemented cup, with a mean follow-up of 27 months. We studied demographic data, complications, especially re-dislocations of the prosthesis and, also the likely causes of system failure analyzed.

RESULTS

In 21.05% (8 cases) were primary surgery and 78.95% were revision surgery (30 cases). The overall survival rate by Kaplan-Meier method was 70.7 months. During follow-up 3 patients died due to causes unrelated to surgery and 2 infections occurred. 12 hips had at least two previous surgeries done. It wasn't any case of aseptic loosening. Four patients presented dislocation, all with a 22 mm head (P=.008). Our statistical analysis didn't found relationship between the abduction cup angle and implant failure (P=.22).

CONCLUSIONS

The ultra high molecular weight polyethylene retentive cup evaluated in this series has provided satisfactory short-term results in hip arthroplasty patients at high risk of dislocation.

[Study of the consistency of a system for preoperative planning digital in total arthroplasty of the hip]

OBJECTIVE

Check the agreement of a preoperative digital templating, compared with the final result in the postoperative radiograph.

MATERIAL AND METHOD

The study was carried out on a 55 total hip prosthesis. A templating-software Neteous (Socincer, Gijón, Spain) was used. Agreement was measured using the Kappa Index for the stem offset or Lin Index for others variables: stem size, cup size, femoral neck length, and the distance from the center of rotation of the femoral head to the lesser trochanter. The percentage of accurate hits was also described.

RESULTS

Stem size: The exact success or error of only one size was of 61.6%. Quantitatively the Lin Index was 0.64 (substantial). Horizontal offset: satisfactory agreement was obtained (Kappa index of 0.75). In 6 cases (10.90%) was changed to lateralized during surgery, for more joint stability. Size of the cup: the agreement obtained was 0.67 (substantial) with a hit grade of 43.6%. Prosthetic neck length: the exact hit or error of only one size were found in 50.9%, moderate level of agreement. Distance from the center of rotation to the lesser trochanter: was observed for almost perfect agreement with Lin Index of 0.95. The exact percentage of hits or gap error less than 5mm was 74.5%.

DISCUSSION AND CONCLUSION

In ours hands, the preoperative templating software analyzed, has provided acceptable agreement rates, when compared with the postoperative result. But it takes more works verified by independent observers.

Body weight and comorbidity predict mortality in COPD patients treated with oxygen therapy

The aim of this study was to investigate the association between clinical variables and all-cause and respiratory mortality in patients with chronic obstructive pulmonary disease (COPD) undergoing long-term oxygen therapy (LTOT). The authors retrospectively studied a historic cohort of 128 patients with COPD (126 males, mean age+/-SD 68.9+/-9.7 yrs, body mass index (BMI) 25.1+/-4.5 kg.m-2, and forced expiratory volume in one second 25.4+/-8.8% predicted), who were being treated with long-term oxygen therapy in a tertiary teaching hospital between 1992 and 1999. Comorbidity, assessed with the Charlson Index, was present in 38% of the patients. Vital status and cause of death were assessed through the population death registry. A total of 78 patients (61%) had died by the end of follow-up. Three-year survival was 55%. Death was due to respiratory causes in 77% of cases. On Cox analysis, BMI<25 kg.m-2, comorbid conditions, age>or=70 yrs and cor pulmonale were associated with all-cause mortality. The BMI and comorbidity were the only significant predictive factors when the analysis was restricted to respiratory mortality. In conclusion, body mass index<25 kg.m-2 and comorbidity were predictors of all-cause and respiratory mortality in a cohort of chronic obstructive pulmonary disease patients treated with long-term oxygen therapy. These factors should be taken into account when considering the management and prognosis of these patients.

Identification of candidate tumor related genes using comprehensive gene expression analysis of neuroblastic tumors

9051

Background: Neuroblastic tumors (NBTs) represent a heterogeneous and relatively well defined spectrum of neoplastic diseases. We performed gene expression analysis to molecularly characterize the distinct clinicobiological subtypes of NBTs. Methods: Gene expression analysis of 106 NBTs (10 ganglioneuromas, 10 stage 4s, 29 loco-regional (stages 1, 2, 3), and 57 stage 4) and 12 neuroblastoma cell lines was performed using Affymetrix Genechip Human Genome U95 Set Arrays. Differential expression between predefined groups of biological and clinical relevance was determined by differences >3 standard deviations between the means for groups, step-down permutation and false discovery rate methods. Results: Gene expression analysis of clinically defined groups including stage 4 infants versus children, metastatic versus non metastatic, and stroma poor loco-regional versus stage 4, revealed that many differentially expressed genes mapped to chromosomal regions with well described recurrent abnormalities in NBTs (chromosomes 1, 11, 17, 19 and X). Pairwise comparison analysis of biologically defined groups, including triploid versus diploid/tetraploid NBTs, identified significantly discriminating genes that map to the same chromosomal regions. Gene expression analysis of MYCN-amplified versus MYCN non amplified NBTs, confirmed a functional overrepresentation for genes involved in protein biosynthesis. Conclusions: Gene expression profile analysis of clinically and biologically relevant subgroups of NBTs revealed differential expression of genes at specific chromosomal regions known to have strong association between genetic alterations and NBT clinical features. The identification of altered expression helps to define critical chromosomal regions and identify tumor related candidate genes within each region.

No significant financial relationships to disclose.

Leuconostoc bacteremia in a healthy infant

Infections by Leuconostoc species bacteria are uncommon, and usually affect patients with an underlying disease, or those fitted with a venous catheter or subjects previously treated with vancomycin. The most common clinical presentation is fever secondary to a central venous line infection. We report a case of Leuconostoc sp. bacteremia in an otherwise apparently healthy 2.5 month-old infant. The patient was successfully treated with cefotaxime. Leuconostoc sp. is an emerging pathogen that should be considered in the differential diagnosis of vancomycin-resistant Gram-positive bacteremia.

Early onset of neonatal sepsis due to group A streptococcus

Neonatal infections by group A beta-hemolytic streptococcus are very rare in the antibiotic era. There are only a few cases in the first 72 hours after birth. The authors describe a case in which it was confirmed that the bacteria responsible, group A beta-hemolytic streptococcus, had grown in the newborn's blood and in the mother's lochia. The transmission mechanisms are also reviewed.

IP3 receptor function and localization in myotubes: an unexplored Ca2+ signaling pathway in skeletal muscle

We present evidence for an unexplored inositol 1,4,5-trisphosphate-mediated Ca2+ signaling pathway in skeletal muscle. RT-PCR methods confirm expression of all three known isotypes of the inositol trisphosphate receptor in cultured rodent muscle. Confocal microscopy of cultured mouse muscle, doubly labeled for inositol receptor type 1 and proteins of known distribution, reveals that the receptors are localized to the I band of the sarcoplasmic reticulum, and this staining is continuous with staining of the nuclear envelope region. These results suggest that the receptors are positioned to mediate a slowly propagating Ca2+ wave that follows the fast Ca2+ transient upon K+ depolarization. This slow wave, imaged using fluo-3, resulted in an increase in nucleoplasmic Ca2+ lasting tens of seconds, but not contraction; the slow wave was blocked by both the inositol trisphosphate receptor inhibitor 2-aminoethoxydiphenyl borate and the phospholipase C inhibitor U-73122. To test the hypothesis that these slow Ca2+ signals are involved in signal cascades leading to regulation of gene expression, we assayed for early effects of K+ depolarization on mitogen-activated protein kinases, specifically extracellular-signal related kinases 1 and 2 and the transcription factor cAMP response element-binding protein (CREB). Within 30-60 seconds following depolarization, phosphorylation of both the kinases and CREB was evident and could be inhibited by 2-aminoethoxydiphenyl borate. These results suggest a signaling system mediated by Ca2+ and inositol trisphosphate that could regulate gene expression in muscle cells.

Characterization of Cr(VI) binding and reduction to Cr(III) by the agricultural byproducts of Avena monida (oat) biomass

Chromium contamination of the environment has become an important issue due to the potential health threat it poses. Conventional technologies to clean up heavy metal ions from contaminated waters have been utilized, but these technologies are not cost-effective. However, the use of agricultural waste byproducts for the removal of Cr(VI) from contaminated waters may be a new cost-effective alternative. Oat byproducts from the Juarez Valley in Mexico were studied for the ability to bind Cr(VI) under different temperature and time conditions. The metal binding ability of oat byproducts was calculated from experimental data collected at temperatures of 8, 26, and 54 degrees C, and time exposures of 1, 6, 24, 48, and 72 h at each temperature. These results showed that the binding of Cr(VI) to oat biomass increased as time and temperature increased. The bound chromium was recovered from the oat biomass by treatment with 0.2M HCl. Through the use of X-ray absorption spectroscopy, the reduction of Cr(VI) to Cr(III) was determined to occur by the oat byproducts. These results indicate that the use of agricultural waste byproducts could be a better alternative for the removal and subsequent reduction of Cr(VI) to Cr(III) from contaminated waters.

Early onset neonatal sepsis due to Neisseria meningitidis B

The onset of meningococcal infection in the first 72 hours after birth has only been reported on a few occasions; The authors describe a case where it was confirmed that the bacteria responsible, Neisseria meningitidis group B, grew in the newborn's blood and in the mother's lochia. The transmission mechanisms are also reviewed.

Genetic differentiation among geographically isolated populations of Criollo cattle and their divergence from other Bos taurus breeds

The microsatellites HEL5, HEL9, INRA063, and BM2113 were used to analyze genetic similarities and differences of geographically isolated Criollo cattle herds in Mexico. Criollo cattle from five counties within the state of Chihuahua and one county from the state of Tamaulipas (n = 60) were sampled. The five counties in Chihuahua included Cerocahui (n = 14), Chinipas (n = 10), Guachochi (n = 15), Morelos (n = 30), and Temoris (n = 9). Samples of DNA were amplified by PCR and separated on a 7% polyacrylamide gel. Microsatellite size was established by comparison to M13mp18 DNA ladder and a documented set of four bovine controls. Allele frequencies and genotypic deviations from Hardy-Weinberg equilibrium were tested using the GENEPOP program. Eleven alleles were generated at HEL5 for the populations sampled (149 to 169 bp). Allele frequencies were greatest for the 163-bp allele in Criollo cattle from Cerocahui, Chinipas, Moralos, and Tamaulipas (0.23 to 0.5). Cattle from Guachochi had an allele frequency of 0.38 for the 151-bp allele, and cattle from Temoris had an allele frequency of 0.25 for the 149- and 167-bp alleles, with no 163-bp allele. Amplification with HEL9 produced 12 alleles (145, 149 to 169 bp) and showed common high-frequency alleles at 149, 157, and 159 bp for animals from all regions. The Chinipas population showed a moderate allele frequency at 145 bp; no other regions contained this allele. For INRA063 there were five alleles with 182 and 184 bp in low frequency. For BM2113 there were 10 alleles in the Criollo cattle (125 to 143 bp), with an equal distribution of frequencies for all alleles. In two regions, Guachochi and Morelos, genotypic frequencies deviated from Hardy-Weinberg equilibrium. Cattle from the Temoris region were genetically most distant from Criollo cattle of the other five regions.

Mapping of a syndrome of X-linked thrombocytopenia with Thalassemia to band Xp11-12: further evidence of genetic heterogeneity of X-linked thrombocytopenia

X-linked thrombocytopenia with thalassemia (XLTT; Online Mendelian Inheritance in Man [OMIM] accession number 314050) is a rare disorder characterized by thrombocytopenia, platelet dysfunction, splenomegaly, reticulocytosis, and unbalanced hemoglobin chain synthesis. In a 4-generation family, the gene responsible for XLTT was mapped to the X chromosome, short arm, bands 11-12 (band Xp11-12). The maximum lod score possible in this family, 2.39, was obtained for markers DXS8054 and DXS1003, at a recombination fraction of 0. Recombination events observed for XLTT and markers DXS8080 and DXS8023 or DXS991 define a critical region that is less than or equal to 7.65 KcM and contains the gene responsible for the Wiskott-Aldrich syndrome (WAS; OMIM accession number 301000) and its allelic variant X-linked thrombocytopenia (XLT; OMIM accession number 313900). Manifestations of WAS include thrombocytopenia, eczema, and immunodeficiency. In WAS/XLT the platelets are usually small, and bleeding is proportional to the degree of thrombocytopenia. In contrast, in XLTT the platelet morphology is normal, and the bleeding time is disproportionately prolonged. In this study no alteration in the WAS gene was detected by Northern blot or Western blot analysis, flow cytometry, or complimentary DNA dideoxynucleotide fingerprinting or sequencing. As has been reported for WAS and some cases of XLT, almost total inactivation of the XLTT gene-bearing X chromosome was observed in granulocytes and peripheral blood mononuclear cells from 1 asymptomatic obligate carrier. The XLTT carrier previously found to have an elevated alpha:beta hemoglobin chain ratio had a skewed, but not clonal, X-inactivation pattern favoring activity of the abnormal allele. Clinical differences and results of the mutation analyses make it very unlikely that XLTT is another allelic variant of WAS/XLT and strongly suggest that X-linked thrombocytopenia mapping to band Xp11-12 is a genetically heterogeneous disorder.