An age-related change in the ipsilateral silent period of a small hand muscle

ObjectiveTo establish the presence or absence of an age effect on the ipsilateral silent period (iSP) for the abductor pollicis brevis (APB) muscle in healthy subjects.MethodsTwenty young adults (10 men, 10 women; age range: 20–40) and 20 older adults (10 men, 10 women; age range: 50–70) were matched by age (+30 years), gender and height (±5 cm). All were right-handed. We investigated the iSP for the APB by applying transcranial magnetic stimulation (TMS) and recording surface electromyograms. The contralateral motor-evoked potential (MEP) onset latency, the iSP onset and end latency (iSPOL and iSPEL) were measured and the iSP duration (iSPD) and transcallosal conduction time (TCT) were calculated. We evaluated the correlation between age and iSP, the latter’s intra- and intersession reproducibility and potential influencing factors.ResultsMean iSPOL, iSPEL and TCT values were significantly greater in older adults (both men and women) than in young adults. Intra- and intersession reproducibility was good. The mean left-side iSPEL and iSPD were longer than the right-side mean values in young adults but not in older adults. In both age groups, women displayed shorter latencies than men.ConclusionsThere is a strong effect of age on iSP parameters.SignificanceOur iSP results may evidence a decrease in transcallosal excitability with age, rather than slowing of the transcallosal interneuron conduction velocity.     

Does Preoperative 25-Hydroxyvitamin D Status Significantly Affect the Calcium Kinetics after Total Thyroidectomy?

Background

Although previous studies have suggested that low preoperative 25-hydroxyvitamin D (25-OHD) is a risk factor for hypocalcemia after total thyroidectomy, the impact of preoperative 25-OHD on calcium (Ca)/parathyroid hormone (PTH) kinetics in the immediate postoperative period remains unclear. The study compared the postoperative Ca/PTH kinetics between different preoperative 25-OHD levels.

Patients

A total of 281 patients who underwent a total thyroidectomy were analyzed. Serum Ca was measured preoperatively within 1 h after surgery (Ca-D0) and on the following morning (Ca-D1). Preoperative 25-OHD was also measured after overnight fasting while postoperative PTH was checked at skin closure on day 0 (PTH-D0) and on the following morning on day 1 (PTH-D1). The Ca/PTH kinetics were compared between three groups (group I: preoperative 25-OHD < 10 ng/mL; group II: 25-OHD = 10–20 ng/mL; group III: 25-OHD > 20 ng/mL).

Results

Group I had significantly lower preoperative Ca (p = 0.016) and Ca-D0 (p = 0.036) but higher PTH-D1 (p = 0.015) than groups II and III. PTH-D0, Ca-D1, and the rate of clinically significant hypocalcemia were similar in the three groups. Group I had a significantly smaller Ca drop (?0.02 vs. 0.01 and 0.02 mmol/L, p = 0.011) and a tendency for a significantly smaller PTH drop (0.4 vs. 0.5 and 1.0 pmol/L, p = 0.073) than groups II and III. PTH-D1 (OR = 1.550) and 25-OHD (OR = 0.958) were independent factors for Ca drop from day 0 to day 1.

Conclusions

Although group I began with lower serum Ca, those patients tended to have a greater PTH response to Ca drop and so preoperative 25-OHD did not significantly affect the overall Ca kinetics from preoperative to day 1.     

Fistula use after concurrent arteriovenous fistula formation and Tenckhoff catheter insertion

A significant proportion of peritoneal dialysis (PD) patients will have abrupt technique failure requiring conversion to haemodialysis, often using temporary vascular catheters as bridging access. However, vascular catheter use has been associated with increased mortality and great effort has been made to reduce their use. Just under two decades ago, a trial of dual arteriovenous fistula (AVF) formation and Tenckhoff catheter insertion reported only 4% of those in whom back‐up fistulae were formed ever used them. Patient demographic, surgical technique and fistula care over those decades have changed substantially, potentially making this practice feasible. Thirty‐five selected patients at Concord Repatriation and General Hospital had AVF formed at the time of Tenckhoff insertion and were entered prospectively into a vascular access database. We retrospectively examined this database with a median follow up of 345 days (interquartile range 183–658). Thirty‐one per cent of all patients used the preformed AVF, and a further 19% who were still on PD had clinically functioning AVF. The vast majority (62%) had abrupt PD technique failure. This is a marked difference to dated reports of AVF use after concurrent PD and AVF formation. It raises the possibility that the formation of back‐up fistula may be another method to reduce the need for vascular catheter use.     

A survey of current practices in the diagnosis of and interventions for inhalational injuries in Canadian burn centres

OBJECTIVE:

To summarize current Canadian practice patterns in the diagnosis of and interventions for inhalation injuries (INHI).

METHODS:

A 10-question survey regarding the diagnosis of and interventions for INHI was sent to the medical directors of all 16 burn centres across Canada.

RESULTS:

The response rate to the survey was 50%. Fibreoptic bronchoscopy is required for the diagnosis of INHI in only four centres (50%). The departments of intensive care, plastic surgery, otolaryngology and respirology are involved in performing fibreoptic bronchoscopy in 87.5%, 37.5%, 12.5% and 12.5% of Canadian burn centres, respectively. Intubation for INHI is most often based on physical examination results (87.5%) and clinical history (75%). The most common physical features believed to be most consistent with INHI are dyspnea (87.5%) and hoarseness (87.5%). Common treatments include intubation (87.5%), routine ventilatory support (87.5%) and chest physiotherapy (75%). None of the centres used nebulized heparin. A total of five centres (62.5%) routinely changed the fluid resuscitation protocol when INHI was diagnosed. Only two centres (25%) routinely used prophylactic antibiotics for INHI.

CONCLUSION:

Prospective, multicentre trials are needed to generate evidence-based consensus in the areas of diagnosis, grading and treatment for INHI in Canada.     

The National Institutes of Health Chemical Countermeasures Research Program (NIH CCRP): A collaborative opportunity to develop effective and accessible chemical medical countermeasures for the American people

The United States Department of Health and Human Services (HHS) leads the nation in preventing, preparing for, and responding to the adverse health effects of public health emergencies and disasters. In addition to biological, radiological and nuclear agents, the risk of a high consequence public health emergency due to the intentional and/or accidental release of chemical agents is a major growing concern of the US government. As such, the federal government is fully committed to address public health security threats posed by chemicals. To enhance chemical emergency preparedness and response, HHS oversees the interdepartmental research, advanced development, regulatory review and approval, procurement, and stockpiling of medical countermeasures (MCMs). Within the National Institute of Health (NIH/HHS), the National Institute of Allergy and Infectious Diseases (NIAID) is responsible for the fundamental research and early development of MCMs to prevent deaths and/or treat injuries during and after emergencies due to large scale chemical exposure. This commentary provides an overview of the NIAID/NIH Chemical Countermeasures Research Program (CCRP) and resources to facilitate the research, discovery, and early development of chemical MCMs. Available product development resources include research funding opportunities, expert advice from the NIH, and preclinical and efficacy service support cores to reduce opportunity costs and entry barriers for prospective developers interested in entering or accelerating the development of chemical MCMs.     

Localization and variable expression of G alpha(i2) in human endometrium and Fallopian tubes

BACKGROUND: Heterotrimeric G proteins take part in membrane-mediated cell signalling and have a role in hormonal regulation. This study clarifies the expression and localization of the G protein subunit G alpha(i2) in the human endometrium and Fallopian tube and changes in G alpha(i2) expression in human endometrium during the menstrual cycle. METHODS: The expression of G alpha(i2) was identified by Polymerase chain reaction (PCR), and localization confirmed by immunostaining. Cyclic changes in G alpha(i2) expression during the menstrual cycle were evaluated by quantitative real-time PCR. RESULTS: We found G alpha(i2) to be expressed in human endometrium, Fallopian tube tissue and in primary cultures of Fallopian tube epithelial cells. Our studies revealed enriched localization of G alpha(i2) in Fallopian tube cilia and in endometrial glands. We showed that G alpha(i2) expression in human endometrium changes significantly during the menstrual cycle, with a higher level in the secretory versus proliferative and menstrual phases (P < 0.05). CONCLUSIONS: G alpha(i2) is specifically localized in human Fallopian tube epithelial cells, particularly in the cilia, and is likely to have a cilia-specific role in reproduction. Significantly variable expression of G alpha(i2) during the menstrual cycle suggests G alpha(i2) might be under hormonal regulation in the female reproductive tract in vivo.     

Evaluation of a Once-Daily Vancomycin Regimen in an Outpatient Leukemia/Bone Marrow Transplant Clinic (OD-VANCO Study)

Background

The Leukemia/Bone Marrow Transplant Program of British Columbia manages patients with high-risk febrile neutropenia and those with non-neutropenic immunocompromised states in an outpatient clinic setting. Because the program treats outpatients only, once-daily administration of IV antibiotics is desirable. A high-dose, once-daily vancomycin nomogram was developed and implemented as part of the antibiotic treatment regimen.

Objective:

To determine if therapeutic vancomycin trough levels could be achieved with a high-dose, once-daily regimen in this outpatient setting.

Methods:

A prospective, single-centre, observational cohort study was conducted over a 7-month period. Outpatients in the Leukemia/Bone Marrow Transplant Program were started on IV vancomycin with the high-dose, once-daily vancomycin nomogram, and outcomes were assessed.

Results:

Of 48 outpatients treated over the 7-month period, 10 (21%) had therapeutic vancomycin trough concentrations (i.e., greater than 10 mg/L). Thirty-five (90%) of the 39 patients with suspected clinical infection experienced clinical cure, and 6 (67%) of the 9 patients with documented microbiological infection experienced microbiological cure. Thirty (62%) of the 48 patients experienced symptoms of “red man syndrome”, and 7 (15%) experienced some degree of nephrotoxicity. Two of 3 patients with laboratory-reported minimum inhibitory concentration (MIC) for identified pathogens had a calculated area under the curve to MIC ratio greater than or equal to 400.

Conclusion:

The high-dose, once-daily vancomycin nomogram was effective in attaining trough levels greater than 10 mg/L in only 21% of patients in this study. A substantial number of adverse drug reactions were observed. Given these results, high-dose, once-daily vancomycin is no longer recommended for outpatient therapy.