Themba Nyirenda

Parkinson disease affects peripheral sensory nerves in the pharynx.

Dysphagia is very common in patients with Parkinson disease (PD) and often leads to aspiration pneumonia, the most common cause of death in PD. Current therapies are largely ineffective for dysphagia. Because pharyngeal sensation normally triggers the swallowing reflex, we examined pharyngeal sensory nerves in PD patients for Lewy pathology.Sensory nerves supplying the pharynx were excised from autopsied pharynges obtained from patients with clinically diagnosed and neuropathologically confirmed PD (n = 10) and healthy age-matched controls (n = 4). We examined the glossopharyngeal nerve (cranial nerve IX), the pharyngeal sensory branch of the vagus nerve (PSB-X), and the internal superior laryngeal nerve (ISLN) innervating the laryngopharynx. Immunohistochemistry for phosphorylated α-synuclein was used to detect Lewy pathology. Axonal α-synuclein aggregates in the pharyngeal sensory nerves were identified in all of the PD subjects but not in the controls. The density of α-synuclein-positive lesions was greater in PD patients with dysphagia versus those without dysphagia. In addition, α-synuclein-immunoreactive nerve fibers in the ISLN were much more abundant than those in cranial nerve IX and PSB-X. These findings suggest that pharyngeal sensory nerves are directly affected by pathologic processes in PD. These abnormalities may decrease pharyngeal sensation, thereby impairing swallowing and airway protective reflexes and contributing to dysphagia and aspiration.

Incidence of Renal Artery Pseudoaneurysm Following Open and Minimally Invasive Partial Nephrectomy: A Systematic Review and Comparative Analysis

PURPOSE Partial nephrectomy is performed for renal masses as a means of preserving renal function. Renal artery pseudoaneurysm is a potential complication of partial nephrectomy. We determined the incidence of renal artery pseudoaneurysm after open and minimally invasive partial nephrectomy, and performed a comparative analysis. MATERIALS AND METHODS We queried the Ovid Medline® and PubMed® databases to locate published reports of renal artery pseudoaneurysm after partial nephrectomy. Studies were included in comparative analysis if they were in English and showed the total number of procedures performed and perioperative complications. RESULTS Included studies represented a total of 5,229 patients, of whom 2,494 and 2,735 underwent open and minimally invasive partial nephrectomy, respectively. A total of 25 and 52 renal artery pseudoaneurysms were reported after open and minimally invasive procedures (weighted 1.00% and 1.96%, respectively). The difference between these 2 values was statistically significant (p ≤ 0.001). Patients diagnosed with renal artery pseudoaneurysm presented a mean of 14.9 days after surgery and 87.3% of them had gross hematuria at presentation. Almost all patients with renal artery pseudoaneurysm were treated with percutaneous angioembolization with 96% success. CONCLUSIONS Although it is rare, the risk of renal artery pseudoaneurysm after partial nephrectomy is significant and should be high on the differential for a patient who presents postoperatively with gross hematuria. The incidence of renal artery pseudoaneurysm is higher after minimally invasive partial nephrectomy than after an open approach. Angioembolization for renal artery pseudoaneurysm after partial nephrectomy offers an excellent success rate and minimal patient morbidity.

Vancomycin-resistant enterococcal bacteraemia and daptomycin: are higher doses necessary?

BACKGROUND The MIC corresponding to daptomycin susceptibility for vancomycin-resistant enterococci (VRE) is ≤ 4 mg/L. Based on the concentration-dependent killing properties of daptomycin, there may be concern about achieving adequate concentrations when the MIC approaches the upper end of the susceptible range (3-4 mg/L). Higher doses of daptomycin may be needed to treat VRE isolates with higher MICs. METHODS We conducted a single-centre retrospective chart review of adult cases with VRE bacteraemia who received daptomycin as initial therapy. The primary outcome was time to microbiological cure (TMC) between standard doses (≤ 6 mg/kg) and high doses (> 6 mg/kg) of daptomycin and whether TMC differed based on MICs. The secondary outcome evaluated the daptomycin MIC distribution and assessed whether recent exposure to vancomycin was associated with higher daptomycin MICs. RESULTS Forty-six cases were included in the primary analysis and 60.9% of patients were neutropenic. The two dose groups differed in the baseline characteristics of age, body mass index, blood culture source and catheter removal. Median TMC was 2 days for both dose groups. There was no significant difference in TMC between MIC subgroups of ≤ 2 mg/L versus >2 and ≤ 4 mg/L. For the secondary analysis 227 VRE isolates were evaluated and 62% had daptomycin MICs of 3-4 mg/L. Each daptomycin MIC group had a similar incidence of prior vancomycin exposure. CONCLUSIONS Based on this retrospective review we did not observe a difference in TMC based on daptomycin dose and MIC; however, there were various limitations to this study, and the study was not powered to detect a difference in TMC. Also, prior vancomycin exposure did not appear to influence daptomycin MICs. The frequency of daptomycin MICs of 3-4 mg/L reported in this study is higher than those reported in the literature.

Health care workers and disaster preparedness: barriers to and facilitators of willingness to respond

BackgroundThere is limited research on preparation of health care workers for disasters. Prior research addressed systems-level responses rather than specific institutional and individual responses.MethodsAn anonymous online survey of hospital employees, who were grouped into clinical and non-clinical staff, was conducted. The objective of this study was to compare perceptions of clinical and non-clinical staff with regard to personal needs, willingness to report (WTR) to work, and level of confidence in the hospital‘s ability to protect safety and provide personal protective equipment (PPE) in the event of a disaster.ResultsA total of 5,790 employees were surveyed; 41 % responded (77 % were women and 63 % were clinical staff). Seventy-nine percent either strongly or somewhat agreed that they know what to do in the event of a disaster, and the majority was willing to report for duty in the event of a disaster. The most common barriers included ‘caring for children’ (55 %) and ‘caring for pets’ (34 %). Clinical staff was significantly more likely than non-clinical staff to endorse childcare responsibilities (58.9 % vs. 48 %) and caring for pets (36 % vs. 30 %, respectively) as barriers to WTR. Older age was a significant facilitator of WTR [odds ratio (OR) 1.49, 95 % CI: 1.27-1.65]. Non-clinical staff was more confident in the hospital’s ability to protect safety and provide PPE compared to clinical staff (OR 1.43, 95 % CI: 1.15-1.78).ConclusionClinical and non-clinical staff differ in the types of barriers to WTR endorsed, as well as their confidence in the hospital’s ability to provide them with PPE and guarantee their safety.

Propranolol for infantile haemangiomas: initiating treatment on an outpatient basis.

INTRODUCTION Propranolol was recently discovered to be an effective treatment for infantile haemangiomas, and varying doses and monitoring regimens have been proposed. Adverse events, although uncommon, have been reported. MATERIALS AND METHODS This was a retrospective chart review of infants with haemangiomas who were started on propranolol at a dose of 3 milligrams per kilogram per day on an outpatient basis. After a baseline cardiac evaluation including an electrocardiogram and an echocardiogram, treatment was initiated during 6 hours of observation. RESULTS A total of 15 patients were identified; however, only 13 returned for at least one follow-up visit. This cohort was followed up for a median of 2.8 months with a range from 0.2 to 10.0. No hypotension, hypoglycaemia, bronchospasm, or clinically significant bradycardia occurred during treatment. All patients had clinical improvement of their haemangiomas. CONCLUSIONS This study suggests that initiating treatment during outpatient observation may be a reasonable alternative to inpatient admission. In addition, expensive testing may not be necessary during pre-treatment screening when the physical examination is normal.

Reinnervation of denervated muscle by implantation of nerve-muscle-endplate band graft to the native motor zone of the target muscle

Motor endplate reinnervation is critical for restoring motor function of the denervated muscle. We developed a novel surgical technique called nerve‐muscle‐endplate band grafting (NMEG) for muscle reinnervation.

Body Mass Index and Abdominal Ultrasound Image Quality A Pilot Survey of Sonographers

The objective was to assess the consensus among sonographers that the quality of abdominal ultrasound (US) images is related to the patient’s body mass index (BMI). Fourteen sonographers completed a 12-item questionnaire to evaluate their experience with abdominal US imaging with respect to image quality in correlation with the patient’s adipose tissue. Of the sonographers sampled, 85.7% agreed that there is an association between the amount of adipose tissue on a patient’s abdomen and the quality of US image obtained; 85.7% also agreed that a normal BMI of 18.5 to 24.9 provides the best US image. However, only 28.6% agreed that normal amounts of adipose tissue produce poor image quality. There appears to be agreement among sonographers that BMI is a factor in obtaining good quality abdominal US images. The general consensus was that the best abdominal US images were obtained in patients with normal BMI, whereas images obtained from patients with BMI 30.0 to 34.9 and to a lesser extent BMI 25.0 to 29.9 were limited in quality.

Nerve growth factor and basic fibroblast growth factor promote reinnervation by nerve−muscle−endplate grafting: NGF and FGF-2 Promote Reinnervation

This study was designed to test whether exogenous application of nerve growth factor (NGF) and basic fibroblast growth factor (FGF‐2) to muscles reinnervated with nerve−muscle−endplate band grafting (NMEG) could promote specific outcomes.

Intraoperative 1-Hour Electrical Nerve Stimulation Enhances Outcomes of Nerve–Muscle-Endplate Band Grafting Technique for Muscle Reinnervation

Background Increasing evidence suggests that 1‐hour electrical nerve stimulation during surgery improves nerve regeneration and functional recovery. However, it remains unknown if this approach has beneficial effects on the outcomes of our recently developed nerve‐muscle‐endplate band grafting‐native motor zone (NMEG‐NMZ) technique for muscle reinnervation. Methods In this study, NMEG‐NMZ transplantation was performed in a rat model. The right sternomastoid muscle was experimentally denervated and immediately reinnervated by implanting a NMEG harvested from the ipsilateral sternohyoid (SH) muscle into the NMZ of the target muscle. Before implantation of the NMEG, the SH nerve branch innervating the NMEG was subjected to intraoperative 1‐hour continuous electrical stimulation (20 Hz). Three months after surgery, the degree of functional recovery was evaluated with muscle force measurement and the extent of nerve regeneration and endplate reinnervation was examined using histological and immunohistochemical methods. Results A combination of NMEG‐NMZ with electrical nerve stimulation resulted in a greater degree of functional recovery than the NMEG‐NMZ alone. The mean muscle force of the treated muscles was 90% of the contralateral control. The muscle mass was recovered up to 90% of the control. The mean number and percentage of area of the regenerated axons in the treated muscles was computed to be 81 and 84% of the control muscles, respectively. On average, 83% of the denervated endplates in the treated muscles were reinnervated by regenerated axons. Conclusion Intraoperative brief nerve stimulation promotes nerve regeneration, endplate reinnervation, and functional recovery of the muscles reinnervated with NMEG‐NMZ technique.

Outcomes of Muscle Reinnervation with Direct Nerve Implantation into the Native Motor Zone of the Target Muscle.

Background Our recent work has demonstrated that the native motor zone (NMZ) within a given skeletal muscle is the best site for muscle reinnervation. This study was designed to explore the outcomes of direct nerve implantation (DNI) into the NMZ of denervated sternomastoid (SM) muscle in a rat model. Methods The right SM muscle was experimentally denervated by transecting its innervating nerve. The proximal stump of the severed SM nerve was immediately implanted into a small muscle slit made in the NMZ of the muscle where denervated motor endplates were concentrated. The outcomes of DNI‐NMZ reinnervation were evaluated 3 months after surgery. Specifically, the degree of functional recovery was examined with muscle force measurement. The extent of nerve regeneration and endplate reinnervation was assessed using histological and immunohistochemical methods. Results This study showed that the mean muscle force of the treated muscles was 64% of the contralateral control. Reinnervated SM muscles weighed 71% of the weight of the control muscles. Abundant regenerated axons were identified in the NMZ of the target muscle. The mean number and area of the regenerated axons in the treated muscles was computed to be 62% and 51% of the control muscles, respectively. On average, 66% of the denervated endplates in the treated muscles were reinnervated by regenerated axons. Conclusion Our results suggest that the NMZ within a muscle is an ideal site for endplate reinnervation and satisfactory functional recovery. Further studies are needed to promote the efficacy of DNI‐NMZ technique for muscle reinnervation.