Quantifying Neck Fibrosis: Establishing the Domain Structure of the Neck Fibrosis Scale

OBJECTIVE

We recently described the development of the Neck Fibrosis Scale (NFS). In this submission, we confirm domain structure and validate a scoring system for the NFS.

STUDY DESIGN

Prospective cross-sectional study.

METHODS

Between January 2020 and December 2021, 127 head and neck cancer patients with varying degrees of cutaneous neck fibrosis completed the original 15 item NFS. Exploratory factor analysis was used to identify optimal groupings with similar underlying factors. The association between the domains of the NFS and various measures of neck morbidity (i.e., construct validity) were assessed using gamma regression.

RESULTS

Exploratory factor analysis confirmed 13 of the 15 items from the NFS mapped onto two factors, which were labelled 'physical' and 'emotional' domains. Of the remaining two items, 'energy' did not load uniquely onto one factor and was removed. 'Neck-swelling' did not load on either factor (loadings <0.3) but was retained within the physical domain based on clinical importance. This resulted in a revised 14-item questionnaire. Internal consistency for these two domains was high (>0.8, p < 0.01). Both the physical and emotional domains of the revised NFS show strong correlation with the neck dissection impairment index and neck range of motion. The physical domain strongly correlated with neck elasticity (0.902 [95%CI 0.839-0.972], p < 0.01). Patients receiving multimodal therapy had physical domain scores that were 31.6% [95% 13.9-51.8] higher (worse) than unimodal therapy patients.

CONCLUSIONS

A domain structure and scoring strategy have been developed for the NFS. Future efforts should be directed toward an evaluation of responsiveness.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2198-2202, 2023.

Experiences and perceptions of receiving and prescribing rehabilitation in adults with cystic fibrosis undergoing lung transplantation

BACKGROUND

Rehabilitation is prescribed to optimize fitness before lung transplantation (LTx) and facilitate post-transplant recovery. Individuals with cystic fibrosis (CF) may experience unique health issues that impact participation.

METHODS

Patient and healthcare provider semi-structured interviews were administered to explore perceptions and experiences of rehabilitation before and after LTx in adults with CF. Interviews were analyzed via inductive thematic analysis.

RESULTS

Eleven participants were interviewed between February and October 2021 (five patients, median 28 (IQR 27-29) years, one awaiting re-LTx, four following first or second LTx) and six healthcare providers. Rehabilitation was delivered both in-person and virtually using a remote monitoring App. Six key themes emerged: (i) structured exercise benefits both physical and mental health, (ii) CF-specific physiological impairments were a large barrier, (iii) supportive in-person or virtual relationships facilitated participation, (iv) CF-specific evidence and resources are needed, (v) tele-rehabilitation experiences during the COVID-19 pandemic resulted in preferences for a hybrid model and (vi) virtual platforms and clinical workflows require further optimization. There was good engagement with remote data entry alongside satisfaction with virtual support.

CONCLUSIONS

Structured rehabilitation provided multiple benefits and a hybrid model was preferred going forward. Future optimization of tele-rehabilitation processes and increased evidence to support exercise along the continuum of CF care are needed.

Human papillomavirus (HPV) vaccination across a cascade of knowledge, willingness, and uptake among gay, bisexual, and other men who have sex with men in Canada's three largest cities

BACKGROUND

Some Canadian jurisdictions offer publicly funded HPV vaccine to gay, bisexual, and other men who have sex with men (GBM) aged ≤26 years. We characterized factors associated with being in different stages of HPV vaccination.

METHODS

Engage is a sexual health study of GBM in the three largest Canadian cities recruited via respondent driven sampling (RDS). We categorized participants as: (1) unaware of HPV vaccine, (2) undecided/unwilling to get vaccinated, (3) willing to get vaccinated, (4) vaccinated with one or more doses. Our RDS-II weighted analyses used multinomial logistic regression to identify factors associated with being in earlier stages of the cascade compared to Stage 4.

RESULTS

Across the cities, 26-40%, 7-14%, 33-39%, and 13-28% were in Stages 1 to 4, respectively. Compared to Stage 4, being in earlier stages of the cascade was associated with bisexual-identification (Stage 1: adjusted odds ratio[aOR] = 2.84, 95% confidence interval[CI] = 1.06-7.62; Stage 2: aOR = 3.09, 95%CI = 1.19-8.05), having immigrated to Canada (Stage 1: aOR = 1.79, 95%CI 1.07-2.99), preference to keep same-sex romantic relationships private (Stage 1: aOR = 1.25, 95% CI = 1.05-1.48; Stage 2: aOR = 1.24, 95%CI = 1.05-1.46), not receiving sexual health information (Stage 1: aOR = 0.31, 95% CI = 0.13-0.71; Stage 2: aOR = 0.27, 95%CI = 0.12-0.64), not accessing a health-care provider (Stage 2: aOR = 0.36, 95%CI = 0.15-0.83), and no past hepatitis A/B vaccination (Stage 1: aOR = 0.16, 95% CI = 0.09-0.30; Stage 2: aOR = 0.18, 95%CI = 0.09-0.35; Stage 3: aOR = 0.38, 95%CI = 0.21-0.61).

DISCUSSION

Interventions are needed to reduce social and financial barriers, increase sexual health knowledge, and improve GBM-competent health-care access to increase vaccine uptake among GBM.

Advance care planning in adults with oral cancer: Multi-institutional cross-sectional study

PURPOSE

Patients undergoing head and neck surgery are often elderly and frail with significant comorbidities. Discussion and documentation of what patients would desire for end-of-life care and decision-making is, therefore, essential for delivering patient-centered care.

MATERIALS AND METHODS

This was a retrospective, cross-sectional study of patients undergoing surgery for head and neck cancer at two large, academic, tertiary care centers in Canada. Advance care planning was defined as any documentation of advance directives, resuscitation orders, or end-of-life care preferences.

RESULTS

Among 301 patients, advance care planning was documented for 31 (10.3%). Patients with locally advanced disease (T3+) were twice as likely to have advance care planning documentation compared to those with early disease (RR 1.97, 95%CI [0.98, 3.97]).

CONCLUSIONS

In this multi-institutional cross-sectional study of two large academic centers, we have demonstrated that advance care planning and documentation is overall poor in patients undergoing surgery for oral cancer. These findings may have health policy implications, as advance care planning is associated with increased patient and provider satisfaction and improved alignment of patient goals and care delivered. Future work will investigate barriers and facilitators to advance care-planning documentation in this setting.

Evaluation of Sarcopenia in Older Patients Undergoing Head and Neck Cancer Surgery

OBJECTIVES/HYPOTHESIS

Sarcopenia is a hallmark of aging and its identification may help predict adverse postoperative events in patients undergoing head and neck surgery. The study objective was to assess the relationship between sarcopenia and postoperative complications and length of stay in patients undergoing major head and neck cancer surgery.

STUDY DESIGN

Prospective cohort study.

METHODS

A prospective cohort study was performed of patients 50 years and older undergoing major head and neck surgery. Sarcopenia was defined as low muscle mass (determined by neck muscle cross-sectional imaging) with either low muscle strength (grip strength) or low muscle performance (timed walk test). Logistic regression was applied on binary outcomes, and linear regression was used for log-transformed length of hospital stay (LOS). Univariate and multivariate analyses were performed.

RESULTS

Of the 251 patients enrolled, pre-sarcopenia was present in 34.9% (n = 87) and sarcopenia in 15.6% (n = 39) of patients. Patients with sarcopenia were more likely to be older (P = .001), female (P = .001), have a lower body mass index (P = .001), and lower preoperative hemoglobin (P < .001). On univariate analysis, the presence and severity of sarcopenia was associated with the development of medical complications (P = .029), higher grade of complications (P = .032), LOS (P = .015), and overall survival (P = .001). On multivariate analysis, sarcopenia was associated with a longer LOS (β = 0.32 [95% CI: 0.19-0.45], P < .001) and worse overall survival (HR = 2.21 [95% CI: 1.01-4.23], P = .017).

CONCLUSIONS

Sarcopenia may aid in the prediction of prolonged hospital stay and death in patients who are candidates for major head and neck surgery.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Human papillomavirus (HPV) vaccine uptake among a community-recruited sample of gay, bisexual, and other men who have sex with men in the three largest cities in Canada from 2017 to 2019

INTRODUCTION

In 2015/2016, Canada's largest provinces implemented publicly-funded human papillomavirus (HPV) vaccination programs for gay, bisexual, and other men who have sex with men (GBM) ≤ 26 years old. We sought to describe HPV vaccine uptake among GBM and determine barriers and facilitators to vaccine initiation with a focus on healthcare access and utilization.

METHODS

Engage is a cohort study among GBM aged 16 + years in three Canadian cities recruited from 2017 to 2019 via respondent driven sampling (RDS). Men completed a comprehensive questionnaire at baseline. By publicly-funded vaccine eligibility (≤26 years old = eligible for vaccination, ≥27 years old = ineligible), we described HPV vaccine uptake (initiation = 1 + dose, completion = 3 doses) and explored factors associated with vaccine initiation using Poisson regression. All analyses were weighted with the RDS-II Volz-Heckathorn estimator.

RESULTS

Across the three cities, 26-35% and 14-21% of men ≤ 26 years and 7-26% and 2-9% of men ≥ 27 years initiated and completed HPV vaccination, respectively. Vaccine initiation was significantly associated with STI/HIV testing or visiting a HIV care specialist in the past six months (≤26: prevalence ratio[PR] = 2.15, 95% confidence interval[CI] 1.06-4.36; ≥27: PR = 2.73, 95%CI 1.14-6.51) and past hepatitis A or B vaccination (≤26: PR = 2.88, 95%CI 1.64-5.05; ≥27: PR = 2.03, 95%CI 1.07-3.86). Among men ≥ 27 years old, vaccine initiation was also positively associated with accessing PrEP, living in Vancouver or Toronto, but negatively associated with identifying as Latin American and increasing age. Vaccine initiation was twice as likely among men ≥ 27 years with private insurance versus no insurance.

CONCLUSIONS

Sixty-five to 74% of men eligible for publicly-funded vaccine across the three cities remained unvaccinated against HPV by 2019. High vaccine cost may partly explain even lower uptake among men ≥ 27 years old. Men seeking sexual health care were more likely to initiate vaccination; bundling vaccination with these services may help improve HPV vaccine uptake.

Evaluation of the Braden scale in predicting surgical outcomes in older patients undergoing major head and neck surgery

BACKGROUND

Being able to predict negative postoperative outcomes is important for helping select patients for treatment as well for informed decision-making by patients. Frailty measures are often time and resource intensive to use as screening measures, whereas the Braden scale, a commonly used measure to assess patients at risk of developing pressure ulcers after surgery, may be a potential tool to predict postoperative complication rates and longer length of stay (LOS) in patients undergoing major head and neck cancer surgery.

METHODS

A retrospective analysis of Braden scale scores was performed on a prospectively collected cohort of patients undergoing major head and neck surgery recruited between December 2011 and April 2014. The association of Braden scale score with the primary outcomes of complications and LOS was analyzed using logistic regression and linear regression models on univariate analysis (UVA), respectively. Multivariate analysis (MVA) was performed based on a backward stepwise selection algorithm.

RESULTS

There were 232 patients with a mean (SD) Braden scale score of 14.9 (2.8) with a range from 9 to 23. The Braden scale (β = -.07 per point; 95% CI -0.09, -0.04, P < .001) was an independent predictor of increased LOS on UVA, but not on MVA when adjusted for other variables. For overall complications, as well as type of complication, the Braden scale score was not a significant predictor of complications on either UVA or MVA.

CONCLUSION

In the sample population, the Braden scale did not demonstrate an ability to predict negative outcomes in head and neck surgery patients.

LEVEL OF EVIDENCE

Level 2b individual cohort study.

Radiographical Spectrum of High-altitude Pulmonary Edema: A Pictorial Essay

Background

High-altitude pulmonary edema (HAPE) is a common cause of hospitalization in high altitude areas with significant morbidity. The clinical presentation of HAPE can overlap with a broad spectrum of cardiopulmonary diseases. Also, it is associated with varied radiological manifestations mimicking other conditions and often leading to unnecessary and inappropriate treatment.

Patients and methods

The primary aim of the study was to study the various radiological manifestations of HAPE through real-world chest radiographs. We present six different chest X-ray patterns of HAPE as a pictorial assay, at initial presentation, and after the resolution of symptoms with supplemental oxygen therapy and bed rest alone.

Results

HAPE can present as bilateral symmetrical perihilar opacities, bilateral symmetrical diffuse opacities, unilateral diffuse opacities, bilateral asymmetrical focal opacities, and even lobar consolidation with lower zone or less commonly upper zonal predilection. These presentations can mimic many common conditions like heart failure, acute respiratory distress syndrome, pulmonary embolism, aspiration pneumonitis, pneumonia, malignancy, and tuberculosis.

Conclusion

A holistic clinical–radiological correlation coupled with analysis of the temporal course can help high-altitude physicians in differentiating true HAPE from its mimics.

How to cite this article

Yanamandra U, Vardhan V, Saxena P, Singh P, Gupta A, Mulajkar D, et al. Radiographical Spectrum of High-altitude Pulmonary Edema: A Pictorial Essay. Indian J Crit Care Med 2021;25(6):668–674.

0675 Nocturnal Oxygen Supplementation With Positive Airway Pressure Therapy For Obesity Hypoventilation Syndrome: Clinical Predictors And Liberation From Oxygen

Introduction

Obesity hypoventilation syndrome (OHS) is associated with a high morbidity and mortality. Many patients require nocturnal supplemental oxygen on top of positive airway pressure (PAP) therapy for hypoxemia independent of apneic events. We need to clinically identify patients likely to require nocturnal oxygen supplementation. Follow up is essential as with adequate control of sleep apnea, hypoxia improves and liberation from nocturnal oxygen supplementation may be achievable.

Methods

Researchers obtained a list of patients with coding diagnosis of OHS, seen at the Jefferson Sleep Center between November 2016 and September 2019. Patients with BMI of ≥ 30 and evidence of hypoventilation were included. Hypoventilation was defined as an elevated CO2 level of ≥ 45 mmHg on blood gas analysis, elevated serum bicarbonate level of ≥ 27 mmol/L or by evidence of nocturnal hypoventilation by AASM criteria on polysomnography. Patients with pulmonary and neuromuscular disorders were excluded

Results

Out of 189 patients reviewed, 36 met the inclusion and exclusion criteria. Nineteen patients (53%) required nocturnal oxygen supplementation. A higher serum bicarbonate level of 33 mmol/L against 30 mmol/L (p=0.0078) and a lower resting awake SaO2 of 89% versus 95% (p &lt;0.01) were observed in the oxygen supplementation group. In polysomnographic data, the oxygen supplementation group had lower SaO2 nadir of 67% versus 73% (p=0.026) and had a longer time with SaO2 &lt;88% at 238.2 minutes versus 65.5 minutes (p &lt;0.01). Nine out of the 19 patients (47%) underwent nocturnal oximetry on PAP and room air. Of these, 4 patients (44%) were liberated from oxygen.

Conclusion

Fifty three percent of patients with OHS required nocturnal oxygen supplementation on top of PAP therapy. Higher serum bicarbonate level and lower resting awake SaO2 are potential clinical predictors of nocturnal oxygen supplementation. After nocturnal oximetry on PAP, 44% were successfully liberated from supplemental oxygen.

Support

 

High-altitude pulmonary oedema: Newer treatment modalities for an age-old problem

Background & objectives

High-altitude pulmonary oedema (HAPE) continues to challenge the healthcare providers at remote, resource-constrained settings. High-altitude terrain itself precludes convenience of resources. This study was conducted to evaluate the rise in peripheral capillary saturation of oxygen (SpO₂) by the use of a partial rebreathing mask (PRM) in comparison to Hudson's mask among patients with HAPE.

Methods

This was a single-centre, randomized crossover study to determine the efficiency of PRM in comparison to Hudson's mask. A total of 88 patients with HAPE referred to a secondary healthcare facility at an altitude of 11,500 feet from January to October 2013 were studied. A crossover after adequate wash-out on both modalities was conducted for first two days of hospital admission. All patients with HAPE were managed with bed rest and stand-alone oxygen supplementation with no adjuvant pharmacotherapy.

Results

The mean SpO₂on ambient air on arrival was 66.92±10.8 per cent for all patients with HAPE. Higher SpO₂values were achieved with PRM in comparison to Hudson's mask on day one (86.08±5.15 vs. 77.23±9.09%) and day two (89.94±2.96 vs. 83.39±5.93%). The difference was more pronounced on day one as compared to day two.

Interpretation & conclusions

Mean SpO₂values were found to be significantly higher among HAPE patients using PRM compared to those on Hudson's mask. Further studies to understand the translation of this incremental response in SpO₂to clinical benefits (recovery times, mortality rates and hospital stay) need to be undertaken.

Sex-associated differences in mitochondrial function in human peripheral blood mononuclear cells (PBMCs) and brain

BACKGROUND

Alzheimer's disease (AD) is the most common form of dementia, and it affects more women than men. Mitochondrial dysfunction (MD) plays a key role in AD, and it is detectable at an early stage of the degenerative process in peripheral tissues, such as peripheral mononuclear blood cells (PBMCs). However, whether these changes are also reflected in cerebral energy metabolism and whether sex-specific differences in mitochondrial function occur are not clear. Therefore, we estimated the correlation between mitochondrial function in PBMCs and brain energy metabolites and examined sex-specific differences in healthy participants to elucidate these issues.

METHODS

The current pilot study included 9 male and 15 female healthy adults (mean age 30.8 ± 7.1 years). Respiration and activity of mitochondrial respiratory complexes were measured using a Clarke-electrode (Oxygraph-2k system), and adenosine triphosphate (ATP) levels were determined using a bioluminescence-based assay in isolated PBMCs. Citrate synthase activity as a mitochondrial marker was measured using a photometric assay. Concentrations of brain energy metabolites were quantified in the same individuals using 1H-magnetic resonance spectroscopy (MRS).

RESULTS

We detected sex-associated differences in mitochondrial function. Mitochondrial complexes I, I+II, and IV and uncoupled respiration and electron transport system (ETS) capacity in PBMCs isolated from blood samples of females were significantly (p < 0.05; p < 0.01) higher compared to males. ATP levels in the PBMCs of female participants were approximately 10% higher compared to males. Citrate synthase (CS) activity, a marker of mitochondrial content, was significantly (p < 0.05) higher in females compared to males. Sex-associated differences were also found for brain metabolites. The N-acetylaspartate (NAA) concentration was significantly higher in female participants compared to males in targeted regions. This difference was observed in white matter (WM) and an area with a high percentage (> 50%) of gray matter (GM) (p < 0.05; p < 0.01). The effect sizes indicated a strong influence of sex on these parameters. Sex-associated differences were found in PBMCs and brain, but the determined parameters were not significantly correlated.

CONCLUSIONS

Our study revealed sex-associated differences in mitochondrial function in healthy participants. The underlying mechanisms must be elucidated in more detail, but our study suggests that mitochondrial function in PBMCs is a feasible surrogate marker to detect differences in mitochondrial function and energy metabolism in humans and it underscores the necessity of sex-specific approaches in therapies that target mitochondrial dysfunction.

Comparison of Optic Nerve Sheath Diameter between both eyes: A Bedside Ultrasonography Approach

Context

Optic nerve sheath diameter (ONSD) has long been accepted as a reliable proxy of intracranial pressure especially in critical care and bedside settings. The present consensus is to measure ONSD in both eyes and take average value, which is cumbersome and a potential cause of discomfort to the patient.

Aim

We aim to compare the values of ONSD of the right and left eye in a random sample as measured by bedside ocular ultrasonography (USG) in Indian adults.

Settings and Design

This was a prospective study conducted from September 2012 to March 2013 in the Department of Internal Medicine of a tertiary care hospital situated at moderate high altitude (11,500 ft) in India.

Materials and Methods

Patients admitted with high altitude pulmonary edema (HAPE) were recruited by convenience sampling. The ONSD of both eyes were measured 3 mm behind the globe using a 7.5 MHz linear probe on the closed eyelids of supine subjects.

Statistical Analysis

Analysis was done using SPSS 17.0.

Results

A total of 47 patients of HAPE were recruited to the study with daily ONSD recording of both eyes during the admission period. The mean ONSD of the left eye was 4.60 (standard deviation [SD] = 0.71) whereas the mean ONSD of right eye 4.59 (SD = 0.72). The ONSD of the right eye and left eye was strongly correlated (correlation coefficient = 0.98 with P < 0.0001). The mean difference in the ONSD of both eyes (right-left) was -0.0044 (SD = 0.11) which was not statistically significant (P = 0.533).

Conclusion

Our results suggest that the difference in ONSD of both eyes is not statistically significant in disease or health. This study also suggests that the ONSD of either eye can be predicted by the other eye recordings. Based on these findings, it can be suggested that during ocular USG for routine bedside/research purposes it is sufficient to measure ONSD of any of the one eye to save time and avoid discomfort to the patient.

Managing High-Altitude Pulmonary Edema with Oxygen Alone: Results of a Randomized Controlled Trial

Yanamandra, Uday, Velu Nair, Surinderpal Singh, Amul Gupta, Deepak Mulajkar, Sushma Yanamandra, Konchok Norgais, Ruchira Mukherjee, Vikrant Singh, Srinivasa A. Bhattachar, Sagarika Patyal, and Rajan Grewal. High-altitude pulmonary edema management: Is anything other than oxygen required? Results of a randomized controlled trial. High Alt Med Biol. 17:294-299, 2016.-Treatment strategies for management of high-altitude pulmonary edema (HAPE) are mainly based on the observational studies with only two randomized controlled trials, thus the practice is very heterogeneous and individualized as per the choice of treating physician. To compare the response to different modalities of therapy in patients with HAPE in a randomized controlled manner. We conducted an open-label, randomized noninferiority trial to compare three modalities of therapy (Therapy 1: supplemental O₂ with oral dexamethasone 8 mg q8 hours [n = 42], Therapy 2: supplemental O₂ with sustained release oral nifedipine 20 mg q8 hours [n = 41], and Therapy 3: only supplemental O₂ [n = 50]). Bed rest was mandated in all patients. The study was conducted in a cohort of previously healthy young lowlander males at an altitude of 3500 m. Baseline characteristics of the patients were comparable in the study arms. Complete response was defined as clinical and radiological resolution of features of HAPE, no oxygen dependency, a normal 6-minute walk test (6MWT) on 2 consecutive days, and normal two-dimensional echocardiography. Results were compared by analysis of variance using SPSS version 16.0. There was no statistical difference in duration of therapy to complete response between the three groups (Therapy 1: 8.1 ± 4.0 days, Therapy 2: 6.7 ± 3.9 days, Therapy 3: 6.8 ± 3.2 days; p = 0.15). There were no deaths in any of the groups. We conclude that oxygen and bed rest alone are adequate therapy for HAPE and that adjuvant pharmacotherapy with either dexamethasone or nifedipine does not hasten recovery.

A case of disseminated superficial porokeratosis associated with giant porokeratosis in pregnancy

A 23-year-old pregnant lady presented with dark raised lesions over face, axillae, and upper limbs of 15-day duration. She was 35 weeks pregnant at the time of onset of the lesions. Dermatological examination revealed hyperpigmented plaques on the face and papules with raised borders in the axillae and proximal arms. Skin biopsy from both the lesions revealed a diagnosis of porokeratosis. She was treated with emollients alone and the lesions regressed four weeks following delivery. This case is being reported for the rare occurrence of the combination of disseminated superficial porokeratosis with giant porokeratosis in pregnancy.

Impact of the HIV epidemic and Anti-Retroviral Treatment policy on lymphoma incidence and subtypes seen in the Western Cape of South Africa, 2002-2009: preliminary findings of the Tygerberg Lymphoma Study Group

The Tygerberg Lymphoma Study Group was constituted in 2007 to quantify the impact of HIV on the pattern and burden of lymphoma cases in the Western Cape of South Africa which currently has an HIV prevalence of 15%. South Africa has had an Anti-Retroviral Treatment (ART) policy and a roll-out plan since 2004 attaining 31% effective coverage in 2009. This study is designed to qualify and establish the impact of HIV epidemic and the ARV roll-out treatment program on the incidence of HIV Related Lymphoma (HRL). Early data document that despite the ART roll out, cases of HRL are increasing in this geographical location, now accounting for 37% of all lymphomas seen in 2009 which is an increase from 5% in 2002. This is in contrast to trends seen in developed environments following the introduction of ART. Also noted are the emergence of subtypes not previously seen in this location such as Burkitt and plasmablastic lymphomas. Burkitt lymphoma is now the commonest HRL seen in this population followed by diffuse large B-cell lymphoma subtypes. The reasons for this observed increase in HRL are not ascribable to improved diagnostic capacity as the tertiary institute in which these diagnoses are made has had significant expertise in this regard for over a decade. We ascribe this paradoxical finding to an ART treatment environment that is ineffective for a diversity of reasons, paramount of which are poor coverage, late commencement of ART and incomplete viral suppression.

Abiotic stress enhances androgenesis from isolated microspores of some legume species (Fabaceae)

To induce androgenesis in field pea, grass pea and the model legume species Medicago truncatula, isolated microspores of various genotypes of these three species were submitted to a range of abiotic stresses prior to and during their initial culture, in order to stimulate them to divide and form embryos. Some stress agents had a positive effect on androgenesis from the treated microspores. Submission of flower buds to a cold period prior to anther excision or microspore isolation, modifying the osmotic pressure of the medium during initial culture and electroporation of isolated microspores were the three major individual stress agents to have an impact on the efficiency of androgenetic proliferation and subsequent differentiation from the microspores of pea, grass pea and M. truncatula genotypes. A combination of osmotic and electric shocks significantly improved responses from isolated microspores and yielded microcalluses and then calluses, but only few underwent morphogenesis. Further work is under way to improve responses and extend them to other genotypes. The results reported here are, to the best of our knowledge, the first successful results from isolated microspores of these species.

A randomized prospective study on the treatment of intra-articular distal radius fractures: open reduction and internal fixation with dorsal plating versus mini open reduction, percutaneous fixation, and external fixation

PURPOSE

To compare 2 methods of surgical treatment for displaced intra-articular fractures of the distal radius: open reduction and internal fixation with dorsal plating (Pi Plate; Synthes, Paoli, PA) versus mini open reduction with percutaneous K-wire and external fixation.

METHODS

Patients with AO type C intra-articular distal radius fractures were randomized into 2 groups: open reduction and internal fixation and dorsal plating or external fixation and K-wires and mini-open reduction. Patients over the age of 70 years with any associated soft-tissue or skeletal injury to the same limb and pre-existing wrist arthrosis or disability were excluded from the study. Objective, subjective, and radiographic outcomes were assessed at 2 weeks, 4 to 6 weeks, 10 to 12 weeks, 6 months, and 1- and 2-year intervals. The minimum follow-up period was 6 months; the average follow-up period was 18 months. The principal outcome analyzed was the Disabilities of the Arm, Shoulder, and Hand score. Secondary outcomes included grip strength, range of motion, surgical procedure time, complications, and radiographic parameters. The groups were equal with respect to age, gender, fracture subtype, and number of workers' compensation cases.

RESULTS

No significant difference was found in the Disabilities of the Arm, Shoulder, and Hand scores, our primary outcome. The dorsal plate group, however, showed a higher complication rate when compared with the external fixator group. The plate group had significantly longer tourniquet times when compared with the external fixator group. The plate group also had higher levels of pain at 1 year when compared with the external fixator group; however, this equalized after hardware removal. The external fixator group showed an average grip strength of 97% compared with the normal side and 86% in the dorsal plate group.

CONCLUSIONS

At midterm analysis the dorsal plate group showed a significantly higher complication rate compared with the external fixator group; therefore enrollment in the study was terminated. The dorsal plate group also showed statistically significant higher levels of pain, weaker grip strength, and longer surgical and tourniquet times. Based on these results we cannot recommend the use of dorsal plates in treating complex intra-articular fractures of the distal radius.

Coordinated secretion of alkaline phosphatase into serum and intestine in fat-fed rats

BACKGROUND

Fat feeding increases the activity of intestinal alkaline phosphatase in the serum. The mechanism underlying this increase is unknown. Surfactant-like particles (SLP) secreted by enterocytes have been implicated in this phenomenon.

OBJECTIVE

To study the effect of feeding fish oil and protein synthesis inhibitors on alkaline phosphatase activity in serum and in different intestinal fractions.

METHODS

Male albino rats were fed 2 mL of fish oil and were injected cycloheximide or actinomycin D. Alkaline phosphatase activity was determined in the serum and intestinal fractions (SLP, mucosa, muscularis).

RESULT

Feeding fish oil significantly elevated alkaline phosphatase activity in serum (p< 0.001) and intestinal mucosa (p< 0.01). Administration of cycloheximide or actinomycin D significantly reduced alkaline phosphatase activity in serum (p< 0.01) and in intestinal mucosa (p< 0.05). BCIP staining of brush border alkaline phosphatase activity in acrylamide gels yielded similar results.

CONCLUSIONS

These findings suggest a co-ordination between alkaline phosphatase synthesis and its assembly into lipoprotein vesicles, such as SLP, secreted by enterocytes in response to fat feeding.

Rituximab for autoimmune haemophilia: a proposed treatment algorithm

We previously reported durable complete responses following brief courses of rituximab and prednisone with or without cyclophosphamide in four patients with autoimmune haemophilia and inhibitor titres of 5-60 BU. We report here responses to this monoclonal anti-CD20 antibody in four additional patients, including two patients with inhibitor titres >200 BU. Factor VIII levels became normal 2-35weeks after 4 or 8 weekly doses of rituximab, brief courses of prednisone and in one patient immunoglobulin. Complete responses are ongoing at 10 months in two patients. Two patients relapsed: a patient whose initial inhibitor titre was 525 BU relapsed at 3.5 months and a long-term prednisone-dependent patient at 8.5 months. Both responded to second courses of rituximab and prednisone and are in remission. Our experience suggests that rituximab is a safe and effective addition to immunosuppression with prednisone and cyclophosphamide to treat autoimmune haemophilia, and may permit early discontinuation or even avoidance of these potentially toxic agents. High-titre inhibitor patients, however, may require multiple courses of rituximab or the addition of cyclophosphamide. Pending randomized studies, we propose an algorithm based on our experience and other reports for incorporating rituximab in the treatment of this rare disorder.

Synthetic mannosides act as acceptors for mycobacterial α1-6 mannosyltransferase

A series of synthetic mannosides was screened in a cell-free system for their ability to act as acceptor substrates for mycobacterial mannosyltransferases. Evaluation of these compounds demonstrated the incorporation of [14C]Man from GDP-[14C]Man into a radiolabeled organic-soluble fraction and analysis by thin layer chromatography and autoradiography revealed the formation of two radiolabeled products. Each synthetic acceptor was capable of accepting one or two mannose residues, resulting in a major and a minor mannosylated product. Both products from each acceptor were isolated and their mass was confirmed by fast-atom bombardment-mass spectrometry (FABMS). Characterization of each mannosylated product by exo-glycosidase digestion. acetolysis and linkage analysis by gas chromatography mass spectrometry of partially per-O-methylated alditols, revealed only alpha1-6-linked products. In addition. the antibiotic amphomycin selectively inhibited the formation of mannosylated products suggesting polyprenolmonophosphate-mannose (C15 50-P-Man) was the immediate mannose donor in all mannosylation reactions observed. The ability of synthetic disaccharides to act as acceptor substrates in this system, is most likely due to the action of a mycobacterial polyprenol-P-Man:mannan alpha1-6 mannosyltransferase involved in the biosynthesis of linear alpha1-6-linked lipomannan.

Ulnar nerve elongation and excursion in the cubital tunnel after decompression and anterior transposition

We studied the elongation and excursion of cadaveric ulnar nerves during elbow flexion in control conditions and after in situ decompression and anterior subcutaneous transposition. We found that the normal nerve had the greatest elongation (23%) and excursion (14 mm) in the epicondylar groove. Decompression did not alter the excursion, but significantly reduced the elongation in the groove (6%) and increased it proximally (19%). After anterior subcutaneous transposition, the nerve segment which was originally in the groove elongated with elbow extension to the same extent as occurred with the normal nerve during flexion.

Feasibility of partial A2 and A4 pulley excision: residual pulley strength

We investigated residual digital flexor pulley strengths after 75% excision of the A2 and A4 pulleys. For direct pull-off tests, A2 and A4 pulleys from cadaveric fingers were tested by pulling on a loop of flexor digitorum profundus tendon through the pulley. For functional loading tests, fingers were positioned with the metacarpophalangeal joint flexed to 90 degrees for A2 testing, and with the proximal interphalangeal joint in 90 degrees flexion for A4 testing (with all other joints in full extension). Excision of 75% of A2 and A4 pulleys reduced pulley strengths determined by both testing methods. For the functional loading tests, which are more clinically relevant, mean tendon forces at failure after partial excision of A2 and A4 pulleys were 224 and 131 N respectively, which is sufficient to withstand flexor tendon forces expected during activities of daily living.

Passive and active rehabilitation for partial lacerations of the canine flexor digitorum profundus tendon in zone II

The purpose of this study was to compare the effect of unrestricted active versus passive mobilization on the gliding function and structural properties (ultimate load and stiffness) of repaired and nonrepaired canine flexor digitorum profundus tendons following partial laceration at 1 week. Using a radiographic method, normalized tendon gliding of the flexor digitorum profundus tendon adjacent to the metacarpal bone and total joint rotation were shown to be significantly greater in passive than in active tendons. Each group differed from their control group, however, by an average of only 5%. Both rehabilitation (active vs. passive) and treatment (repair vs. nonrepaired) of the partial tendon laceration significantly affected gap formation. Both active rehabilitation and repair of the laceration significantly increased gap formation compared with passive rehabilitation and nonrepair of the partial laceration. Rehabilitation did not significantly affect the normalized ultimate loads and stiffness in the passive and active groups but the nonrepair groups displayed significantly higher ultimate loads and stiffness than the repair groups.

Feasibility of partial A2 and A4 pulley excision: effect on finger flexor tendon biomechanics

We investigated the effect of partial excision of the A2 and A4 digital pulleys, separately and in combination, on finger angular rotation and the energy for finger flexion. Statistically significant decreases in angular rotation resulted only after 50% and 75% excision of A2, A4, or A2 and A4 in combination. Work of flexion trends were weak and none of the changes were statistically significant. Although optimal finger function relies on the integrity of the A2 and A4 pulleys to maintain the efficiency of the digital flexor system, these data suggest that the A2 and A4 pulleys can be excised up to 25%, either separately or in combination, without significant effects on angular rotation. Decreases in total angular range of motion after 50% and 75% pulley excision were small, even for combined pulley excision (9 degrees +/- 3 degrees and 15 degrees +/- 5 degrees [mean +/- SD], respectively), and may be clinically acceptable.

Mapping of a new autosomal dominant spinocerebellar ataxia to chromosome 22

The autosomal dominant cerebellar ataxias (ADCAs) are a clinically and genetically heterogeneous group of disorders. The clinical symptoms include cerebellar dysfunction and associated signs from dysfunction in other parts of the nervous system. So far, five spinocerebellar ataxia (SCA) genes have been identified: SCA1, SCA2, SCA3, SCA6, and SCA7. Loci for SCA4 and SCA5 have been mapped. However, approximately one-third of SCAs have remained unassigned. We have identified a Mexican American pedigree that segregates a new form of ataxia clinically characterized by gait and limb ataxia, dysarthria, and nystagmus. Two individuals have seizures. After excluding all known genetic loci for linkage, we performed a genomewide search and identified linkage to a 15-cM region on chromosome 22q13. A maximum LOD score of 4.3 (recombination fraction 0) was obtained for D22S928 and D22S1161. This distinct form of ataxia has been designated "SCA10." Anticipation was observed in the available parent-child pairs, suggesting that trinucleotide-repeat expansion may be the mutagenic mechanism.

Targeted disruption of SHIP leads to hemopoietic perturbations, lung pathology, and a shortened life span

SHIP is a 145-kD SH2-containing inositol-5-phosphatase widely expressed in hemopoietic cells. It was first identified as a tyrosine phosphoprotein associated with Shc in response to numerous cytokines. SHIP has been implicated in FcgammaRIIB receptor-mediated negative signaling in B cells and mast cells and is postulated to down-regulate cytokine signal transduction in myeloid cells. To define further its role in the proliferation and differentiation of hemopoietic progenitors, as well as its function in mature cells, we have generated embryonic stem cells and mice bearing a targeted disruption of both SHIP alleles. Here we show that although SHIP null mice are viable and fertile, they fail to thrive and survival is only 40% by 14 weeks of age. Mortality is associated with extensive consolidation of the lungs resulting from infiltration by myeloid cells. Increased numbers of granulocyte-macrophage progenitors are observed in both the bone marrow and spleen of SHIP-/- mice, perhaps as a consequence of hyper-responsiveness to stimulation by macrophage-colony stimulating factor, granulocyte-macrophage colony stimulating factor, interleukin-3, or Steel factor as observed in vitro. In contrast, numbers of bone marrow lymphoid and late erythroid progenitors (CFU-E) are reduced. Thus, homozygous disruption of SHIP establishes the crucial role of this molecule in modulating cytokine signaling within the hemopoietic system and provides a powerful model for further delineating its function.

The effect of partial excision of the A2 and A4 pulleys on the biomechanics of finger flexion

The purpose of this study was to investigate the effect of partial excision of the A2 and A4 pulleys on digital angular rotation and the energy required to flex the finger. Partial excision of A2 resulted in a statistically significant decrease in angular rotation of 3 and 5% after 50 and 75% excision, respectively. Partial excision of A4 failed to produce any significant differences in angular rotation. Combined partial excision of A2 and A4 resulted in a significant decrease of 5 and 8% after 50 and 75% excision, respectively. Significant differences in work of flexion occurred only after excision of 75% of the A2 pulley. Although optimal finger function relies on the integrity of the A2 and A4 pulleys which maintain the efficiency of the digital flexor system, these data suggest that 25% of the A2 pulley, up to 75% of the A4 and 25% of the A2 and A4 together can be excised without significant effects on angular rotation.

The effects of multiple-strand suture methods on the strength and excursion of repaired intrasynovial flexor tendons: a biomechanical study in dogs

This study was designed to determine the effects of in vivo multistrand, multigrasp suture techniques on the strength and gliding of repaired intrasynovial tendons when controlled passive motion rehabilitation was used. Twenty-four adult mongrel dogs were divided into 4 groups and their medial and lateral forepaw flexor tendons were transsected and sutured by either the Savage, the Tajima, the Kessler, or the recently developed 8-strand suture method. The tendon excursion, joint rotation, and tensile properties of the repaired tendons were evaluated biomechanically at 3 and 6 weeks after surgery. It was found that neither time nor suture method significantly effected proximal and distal interphalangeal joint rotation or tendon excursion when the 4 techniques were compared to each other. Normalized load value (experimental/control) was significantly affected by both the suture method and the amount of time after surgery, however. The Savage and 8-strand repair methods had significantly greater strength than did the Tajima method at each time interval (p < .05 for each comparison). In addition, the 8-strand method had significantly greater normalized load values than did the Savage method at each time interval (p < .05 for each comparison). Normalized stiffness (experimental/control) for the 8-strand repair method was significantly greater than that for the Tajima and Savage methods at 3 and 6 weeks after surgery (p < .05). In addition, the normalized stiffness values for the 6-week groups was significantly greater than those for the 3-week groups (p < .05). It was concluded that the method of tendon suture was a significant variable insofar as the regaining of tendon strength was concerned and that the newer low-profile 8-strand repair method significantly expands the safety zone for the application of increased in vivo load during the early stages of rehabilitation.

Human acetyltransferase polymorphisms

Conjugation of primary amino and hydroxylamino groups with acetate, catalyzed by acetyl CoA-dependent arylamine acetyltransferase (NAT) enzymes, may play an important role in the intricate series of metabolic pathways that produce or prevent toxicity following exposure to homo- and heterocyclic arylamine and hydrazine xenobiotics. Two independently regulated and kinetically distinct human acetyltransferases are now known to exist, namely NAT1 and NAT2. Interindividual variation in NAT2 function is associated with the classical isoniazid acetylation polymorphism which was discovered over forty years ago. At last count, fifteen variant alleles at the NAT2 gene locus have been linked to the isoniazid 'acetylator phenotype', and each of these can be identified in population studies using specific PCR-based genotyping tests. On the other hand, NAT1 shows kinetic selectivity for compounds whose disposition is unrelated to the classical isoniazid acetylation polymorphism. NAT1 expression is also phenotypically variable in human populations, at least in part due to allelic differences at the NAT1 gene locus. Nine NAT1 variant alleles have been described to date, of which NAT1* 14 and NAT1* 15 clearly produce defective NAT1 proteins and lead to functional impairment in the metabolism of NAT1-selective substrates both in vivo and in vitro. On the other hand, it has been reported that the NAT1* 10 variant associates with elevated NAT1 activity and increased risk for cancers of the bladder and colon. Because of the important toxicologic consequences of allelic variation in NAT1 and NAT2 function for the metabolic activation of arylamine and heterocyclic amine procarcinogens, further studies are needed to improve our understanding of the extent of NAT allelic variation, to determine the functional capacity of each variant gene product, and to develop accurate methods of detecting them in population and epidemiological studies.

Isolation of chromosome 18-specific brain transcripts as positional candidates for bipolar disorder

Several studies have proposed the existence of susceptibility loci for bipolar disorder on chromosome 18. To identify possible candidate genes for this disease, we isolated brain-expressed transcripts by direct cDNA selection on chromosome 18-specific biotinylated cosmid clones. Longer cognate cDNA clones of the selected cDNAs were isolated from a normalized infant brain cDNA library. Physical mapping by PCR on a panel of somatic cell hybrids was conducted by the use of primers derived from partial sequences on either the 5' or 3' ends of the clones. In our initial analysis, 48 cDNA clones were found to be chromosome 18-specific, mapping to different subchromosomal regions. Sequence redundancy among these clones yielded 30 unique transcripts, five of which were represented in previously known genes. Further sequencing of the remaining 25 unique cDNA clones confirmed the absence of significant homology to known genes, indicating that these transcripts represented novel genes. Mapping with the use of a radiation hybrid panel positioned the brain cDNAs to within = 100 to 1100 kb from reference sequence tag sites (STSs) and assembled them into six high resolution linkage groups. The majority of the transcripts were found to cluster to discrete locations on 18p and 18q, previously hypothesized as susceptibility regions for bipolar disorder, identifying them as positional candidate genes.

Avulsion of the tibial tuberosity: muscles too strong for a growth plate

PURPOSE

To ascertain whether there were significant knee extension strength differences between two adolescent male gymnasts (patient 1: age, 14.5 years; height, 159.3 cm; weight, 52.2 kg; patient 2: age, 15 years; height, 160.6 cm; weight, 54.8 kg) with avulsion of the tibial tuberosity associated with avulsion of the patellar tendon.

CASE SUMMARY

Two adolescent male gymnasts underwent open reduction and internal fixation for avulsion of the tibial tuberosity associated with avulsion of the patellar tendon. Isometric extension strength of the contralateral uninjured knee and of the operated knee was significantly greater than for nonathletic adolescents of the same age (one-way analysis of variance [ANOVA], p = 0.001), and was at a higher part of normal strength than their gymnastic peers.

DISCUSSION

A maximal contraction of the quadriceps is able to overcome the strength of the upper tibial epiphysis disrupting the extensor mechanism of the knee.

RELEVANCE

Greater-than-usual strength, although normally of no undesired consequence, may play a role in avulsion injuries of major muscles.

Bundle pattern of the flexor digitorum profundus tendon in zone II of the hand: a quantitative assessment of the size of a laceration

Assessing the cross-sectional area of a partial laceration of a flexor digitorum profundus tendon based on its width, using magnification and calipers, is often inaccurate. As the threshold for repairing a partial laceration for most surgeons is the involvement of 50% of the tendon area, an accurate method of naked-eye evaluation to detect a 50% (or larger, or smaller) laceration was developed. This assessment is based on the size of the radial and ulnar bundles in the tendon. The relative area of the two bundles at four levels in zone II in the index, middle, ring, and small fingers was measured. In the index and small fingers, the ulnar bundle had a mean area consistently greater than and the radial bundle consistently less than 50% of the total tendon area. In the middle finger, the mean areas of both bundles were close to 50% of the total tendon area, but the radial bundle was reduced at the level of the proximal interphalangeal joint and distally. In the ring finger, both bundles remained close to 50% of the total tendon area at all levels. The bundles involved in a laceration can be easily identified with the naked eye; the data provided by this study may improve the accuracy of partial laceration size assessment.

Does the internal thoracic artery graft delay the recovery of myocardial metabolism?

BACKGROUND

The left internal thoracic artery (LITA) bypass graft to the left anterior descending artery has greater long-term patency than a saphenous vein graft. However, surgeons may be reluctant to use the LITA graft in some patients because they are unable to deliver cardioplegia to the left anterior descending artery territory.

METHODS

We compared the myocardial levels of high-energy phosphates and their metabolites in patients who received an LITA graft with those in patients who received a saphenous vein graft to the left anterior descending artery territory during elective coronary artery bypass grafting. Right and left ventricular biopsy specimens were obtained at three times: before aortic cross-clamping, after cross-clamp removal, and after 10 minutes of reperfusion.

RESULTS

No differences were found between the LITA graft group and the saphenous vein graft group in any right ventricular metabolites. There was an improvement in myocardial protection over time and a higher proportion of LITA graft patients in the late time period (early group, 63% versus late group, 80%; p < 0.01). Within each time period, there were no differences between the LITA and saphenous vein graft groups. Among patients receiving cold antegrade cardioplegia, the myocardial levels of high-energy phosphates were better preserved in those receiving an LITA graft.

CONCLUSIONS

Advances in myocardial protection have led to improved preservation of high-energy phosphate levels after cardioplegic arrest. In patients undergoing elective coronary artery bypass grafting, the use of an LITA graft does not adversely affect myocardial metabolism. Further investigations are required to determine the effects of the use of the LITA during urgent or emergent procedures.

Tensile properties of the interosseous membrane of the human forearm

The interosseous membrane is a structure deep in the forearm that joins the radius and the ulna. It is made up of membranous and ligamentous regions. Two main ligamentous structures have been described: a prominent central fiber group, the "central band," and a smaller proximal fibrous band, the "oblique cord." Many authors believe that the central band plays a biomechanical role in the normal and fractured forearm and that it may function much like a ligament. The objective of this study was to determine the tensile properties of the central band. Eighteen fresh frozen forearms from cadavers (45-70 years of age, both sexes) were used. A fiber bundle of the central band was subjected to a uniaxial tensile test to failure in a materials testing machine, and its tensile properties were calculated. Stiffness, ultimate load, and energy absorbed to failure were expressed as a function of specimen width. The central band structure had a stiffness of 13.1 +/- 3.0 N/mm per mm width and an ultimate load of 56.6 +/- 15.1 N per mm width (mean +/- SD). The tissue of the central band displayed a modulus of 608.1 +/- 160.2 MPa, ultimate tensile strength of 45.1 +/- 10.3 MPa, and strain at failure of 9.0 +/- 2.0%. This study demonstrated that the central band is comprised of strong tissue. The material properties of the central band compare with those of patellar tendon: modulus is 120% and ultimate tensile strength is 84% that of patellar tendon. As a structure, the interosseous membrane is stiff and capable of bearing high loads. Although load distribution across the central band is unknown, a 1.7 cm wide, evenly loaded homogenous portion of the central band would possess a stiffness comparable with that of the anterior cruciate ligament. The results of this study provide a basis for future analyses of radioulnar stability and load transfer.