Severe acute myositis and myocarditis on initiation of 6-weekly pembrolizumab post-COVID-19 mRNA vaccination

We describe three cases of critical acute myositis with myocarditis occurring within 22 days of each other at a single institution, all within 1 month of receiving the initial cycle of the anti-PD-1 drug pembrolizumab. Analysis of T cell receptor repertoires from peripheral blood and tissues revealed a high degree of clonal expansion and public clones between cases, with several T cell clones expanded within the skeletal muscle putatively recognizing viral epitopes. All patients had recently received a COVID-19 mRNA booster vaccine prior to treatment and were positive for SARS-CoV2 Spike antibody. In conclusion, we report a series of unusually severe myositis and myocarditis following PD-1 blockade and the COVID-19 mRNA vaccination.

IFNγ signaling in cytotoxic T cells restricts anti-tumor responses by inhibiting the maintenance and diversity of intra-tumoral stem-like T cells

IFNγ is an immune mediator with concomitant pro- and anti-tumor functions. Here, we provide evidence that IFNγ directly acts on intra-tumoral CD8 T cells to restrict anti-tumor responses. We report that expression of the IFNγ receptor β chain (IFNγR2) in CD8 T cells negatively correlates with clinical responsiveness to checkpoint blockade in metastatic melanoma patients, suggesting that the loss of sensitivity to IFNγ contributes to successful antitumor immunity. Indeed, specific deletion of IFNγR in CD8 T cells promotes tumor control in a mouse model of melanoma. Chronic IFNγ inhibits the maintenance, clonal diversity and proliferation of stem-like T cells. This leads to decreased generation of T cells with intermediate expression of exhaustion markers, previously associated with beneficial anti-tumor responses. This study provides evidence of a negative feedback loop whereby IFNγ depletes stem-like T cells to restrict anti-tumor immunity. Targeting this pathway might represent an alternative strategy to enhance T cell-based therapies.

IL7 genetic variation and toxicity to immune checkpoint blockade in patients with melanoma

Treatment with immune checkpoint blockade (ICB) frequently triggers immune-related adverse events (irAEs), causing considerable morbidity. In 214 patients receiving ICB for melanoma, we observed increased severe irAE risk in minor allele carriers of rs16906115, intronic to IL7. We found that rs16906115 forms a B cell-specific expression quantitative trait locus (eQTL) to IL7 in patients. Patients carrying the risk allele demonstrate increased pre-treatment B cell IL7 expression, which independently associates with irAE risk, divergent immunoglobulin expression and more B cell receptor mutations. Consistent with the role of IL-7 in T cell development, risk allele carriers have distinct ICB-induced CD8+ T cell subset responses, skewing of T cell clonality and greater proportional repertoire occupancy by large clones. Finally, analysis of TCGA data suggests that risk allele carriers independently have improved melanoma survival. These observations highlight key roles for B cells and IL-7 in both ICB response and toxicity and clinical outcomes in melanoma.

Ten year real world experience with ultrafiltration for the management of acute decompensated heart failure

Background

Randomized controlled trials (RCT) of ultrafiltration (UF) have demonstrated conflicting results regarding its efficacy and safety.

Objective

We reviewed 10 years of data for adjustable UF during heart failure hospitalizations in a real world cohort.

Methods

We performed a retrospective, single center analysis of 335 consecutive patients treated with adjustable rate UF using the CHF Solutions Aquadex Flex Flo System from 2009 to 2019.

Results

Compared to previous RCTs investigating UF, our cohort was older, with worse renal impairment and more antecedent HF hospitalizations in the year preceding therapy. Mean fluid removal with UF was 14.6 l. Mean weight loss with UF was 15.6 lbs (range 0.2-57 lbs) and was sustained at 1-2 week follow-up. Mean creatinine change upon stopping UF, at discharge and follow-up (mean 30 days) was +0.11 mg/dl, +0.07 mg/dl and +0.11 mg/dl, respectively. HF rehospitalizations at 30 days, 90 days and 1 year were 12.4 %, 14.9 % and 27.3 % respectively. On average patients had 1.74 fewer hospitalizations for HF in the year following UF when compared to 12 months preceding UF. Major bleeding defined as requiring discontinuation of anticoagulation occurred in 3.6 % of patients.

Conclusions

Compared with previous UF trials, our study demonstrates that UF compares favorably for HF rehospitalizations, renal function response, and weight/volume loss. Importantly, our real world experience allowed for the adjustment of UF rate during therapy and we believe this is a major contributor to our favorable outcomes. In clinical practice, UF can be a safe and effective strategy for decongestion.

Reduction in Chest CT Severity and Improved Hospital Outcomes in SARS-CoV-2 Omicron Compared with Delta Variant Infection

Background The SARS-Cov-2 Omicron variant demonstrates rapid spread but reduced disease severity. Studies evaluating lung imaging findings of Omicron infection versus non-Omicron infection remain lacking. Purpose To compare the Omicron variant with the SARS-CoV-2 Delta variant according to their chest CT radiologic pattern, biochemical parameters, clinical severity, and hospital outcomes after adjusting for vaccination status. Materials and Methods This retrospective study included hospitalized adult patients with reverse transcriptase-polymerase chain reaction test results positive for SARS-CoV-2, with CT pulmonary angiography performed within 7 days of admission between December 1, 2021, and January 14, 2022. Multiple readers performed blinded radiologic analyses that included RSNA CT classification, chest CT severity score (CTSS) (range, 0 [least severe] to 25 [most severe]), and CT imaging features, including bronchial wall thickening. Results A total of 106 patients (Delta group, n = 66; Omicron group, n = 40) were evaluated (overall mean age, 58 years ± 18 [SD]; 58 men). In the Omicron group, 37% of CT pulmonary angiograms (15 of 40 patients) were categorized as normal compared with 15% (10 of 66 patients) of angiograms in the Delta group (P = .016). A generalized linear model was used to control for confounding variables, including vaccination status, and Omicron infection was associated with a CTSS that was 7.2 points lower than that associated with Delta infection (β = -7.2; 95% CI: -9.9, -4.5; P < .001). Bronchial wall thickening was more common with Omicron infection than with Delta infection (odds ratio [OR], 2.4; 95% CI: 1.01, 5.92; P = .04). A booster shot was associated with a protective effect for chest infection (median CTSS, 5; IQR, 0-11) when compared with unvaccinated individuals (median CTSS, 11; IQR, 7.5-14.0) (P = .03). The Delta variant was associated with a higher OR of severe disease (OR, 4.6; 95% CI: 1.2, 26; P = .01) and admission to a critical care unit (OR, 7.0; 95% CI: 1.5, 66; P = .004) when compared with the Omicron variant. Conclusion The SARS-CoV-2 Omicron variant was associated with fewer and less severe changes on chest CT images compared with the Delta variant. Patients with Omicron infection had greater frequency of bronchial wall thickening but less severe disease and improved hospital outcomes when compared with patients with Delta infection. © RSNA, 2022 Online supplemental material is available for this article.

An immunodominant NP105-113-B*07:02 cytotoxic T cell response controls viral replication and is associated with less severe COVID-19 disease

NP105-113-B*07:02-specific CD8+ T cell responses are considered among the most dominant in SARS-CoV-2-infected individuals. We found strong association of this response with mild disease. Analysis of NP105-113-B*07:02-specific T cell clones and single-cell sequencing were performed concurrently, with functional avidity and antiviral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with T cell receptor usage, transcriptome signature and disease severity (acute n = 77, convalescent n = 52). We demonstrated a beneficial association of NP105-113-B*07:02-specific T cells in COVID-19 disease progression, linked with expansion of T cell precursors, high functional avidity and antiviral effector function. Broad immune memory pools were narrowed postinfection but NP105-113-B*07:02-specific T cells were maintained 6 months after infection with preserved antiviral efficacy to the SARS-CoV-2 Victoria strain, as well as Alpha, Beta, Gamma and Delta variants. Our data show that NP105-113-B*07:02-specific T cell responses associate with mild disease and high antiviral efficacy, pointing to inclusion for future vaccine design.

Parenchymal involvement on CT pulmonary angiography in SARS-CoV-2 Alpha variant infection and correlation of COVID-19 CT severity score with clinical disease severity and short-term prognosis in a UK cohort

AIM

To determine if there is a difference in radiological, biochemical, or clinical severity between patients infected with Alpha-variant SARS-CoV-2 compared with those infected with pre-existing strains, and to determine if the computed tomography (CT) severity score (CTSS) for COVID-19 pneumonitis correlates with clinical severity and can prognosticate outcomes.

MATERIALS AND METHODS

Blinded CTSS scoring was applied to 137 hospital patients who had undergone both CT pulmonary angiography (CTPA) and whole-genome sequencing of SARS-CoV-2 within 14 days of CTPA between 1/12/20–5/1/21.

RESULTS

There was no evidence of a difference in imaging severity on CTPA, viral load, clinical parameters of severity, or outcomes between Alpha and preceding variants. CTSS on CTPA strongly correlates with clinical and biochemical severity at the time of CTPA, and with patient outcomes. Classifying CTSS into a binary value of “high” and “low”, with a cut-off score of 14, patients with a high score have a significantly increased risk of deterioration, as defined by subsequent admission to critical care or death (multivariate hazard ratio [HR] 2.76, p<0.001), and hospital length of stay (17.4 versus 7.9 days, p<0.0001).

CONCLUSION

There was no evidence of a difference in radiological severity of Alpha variant infection compared with pre-existing strains. High CTSS applied to CTPA is associated with increased risk of COVID-19 severity and poorer clinical outcomes and may be of use particularly in settings where CT is not performed for diagnosis of COVID-19 but rather is used following clinical deterioration.

Immune checkpoint blockade sensitivity and progression-free survival associates with baseline CD8+ T cell clone size and cytotoxicity

[Figure: see text].

Identification of neutralising pembrolizumab anti-drug antibodies in patients with melanoma

Development of anti-drug antibodies (ADAs) can interfere with therapeutic monoclonal antibodies and may lead to drug neutralisation and clinical disease progression. Measurement of circulating drug levels and development of ADAs in the setting of anti-programmed cell death-1 agent pembrolizumab has not been well-studied. Enzyme-linked immunosorbent assays were used to measure pembrolizumab drug level and ADAs in 41 patients with melanoma at baseline, Time-point 1 (3 weeks) and Time-point 2 (21 weeks). Assay results were related to patient demographics and clinical outcome data at 6 months. The median pembrolizumab drug level at 3 weeks was 237 ng/μL and did not correlate with age, sex or body surface area.17/41 patients had an ADA detected at any timepoint, with the highest prevalence at Timepoint 1 (median concentration = 17 ng/μL). The presence of an ADA did not correlate with clinical progression at 6 months. 3/41 (7%) of patients displayed a falling pembrolizumab drug level and rising ADA titre between Timepoint 1 and 2 suggestive of a neutralising ADA. Pembrolizumab drug levels and ADAs can be readily measured. The rates of total and treatment-emergent ADAs may be higher in “real-word” settings than those previously reported. Larger studies are needed to determine effect of neutralising ADAs on long-term clinical outcome.

Checkpoint-blocker-induced autoimmunity is associated with favourable outcome in metastatic melanoma and distinct T-cell expression profiles

BACKGROUND

Immune checkpoint blockers (ICBs) activate CD8⁺ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.

METHODS

Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab-sICB) or combination (nivolumab and ipilimumab-cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8⁺ T cells was sequenced and differential gene expression according to irAE development assessed.

RESULTS

58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9-33.4) versus not-reached (P = 2.8 × 10^-6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8⁺ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.

CONCLUSIONS

Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.

Chest CT screening for COVID-19 in elective and emergency surgical patients: experience from a UK tertiary centre

AIM

To determine the incidence of possible COVID-19-related lung changes on preoperative screening computed tomography (CT) for COVID-19 and how their findings influenced decision-making. To also to determine whether the patients were managed as COVID-19 patients after their imaging findings, and the proportion who had SARS-CoV2 reverse transcriptionpolymerase chain reaction (RT-PCR) testing.

MATERIALS AND METHODS

A retrospective study was undertaken of consecutive patients having imaging prior to urgent elective surgery (n=156) or acute abdominal imaging (n=283). Lung findings were categorised according to the British Society of Thoracic Imaging (BSTI) guidelines. RT-PCR testing, management, and outcomes were determined from the electronic patient records.

RESULTS

3% (13/439) of CT examinations demonstrated findings of classic/probable COVID-19 pneumonia, whilst 4% (19/439) had findings indeterminate for COVID-19. Of the total cohort, 1.6% (7/439) subsequently had confirmed RT-PCR-positive COVID-19. Importantly, all the patients with a normal chest or alternative diagnoses on CT who had PCR testing within the next 7 days, had a negative RT-PCR (92/407). There was a change in surgical outcome in 6% (10/156) of the elective surgical cohort with no change to surgical management was demonstrated in the acute abdominal emergency cohort requiring surgery (2/283).

CONCLUSION

There was a 7% (32/439) incidence of potential COVID-19-related lung changes in patients having preoperative CT. Although this altered surgical management in the elective surgical cohort, no change to surgical management was demonstrated in the acute abdominal emergency cohort requiring surgery.

Tumor heterogeneity: does it matter?

Introduction: It has long been recognized that tumors are composed of a mosaic of cells and numerous methods have been developed to detect tumor heterogeneity, including in situ hybridization, multi-regional sampling, cytological assays, and whole genome and single cell sequencing. Using these methods, heterogeneity has been observed at the genetic, epigenetic, and phenotypic level in numerous cancers. With the advent of deep sequencing technology, we now appreciate a greater complexity of distinct genotypes and phenotypes that drive the biological behavior of cancer. Despite decades of progress in detecting tumor heterogeneity, the question remains: to what extent does it matter? Areas covered: This review explores the evidence for and against the importance of tumor heterogeneity in three main areas: prognostication, development of targeted therapeutics and tumor resistance; summarizing current understanding before evaluating ongoing experimental and clinical developments. Expert opinion: Theoretical understanding and in vitro detection of intratumour heterogeneity promises much but is yet to translate into meaningful clinical benefit. However, the recent emergence of a host of technological innovations and upcoming clinical trials may soon change the landscape of this field.

Is microwave ablation an alternative to stereotactic ablative body radiotherapy in patients with inoperable early-stage primary lung cancer?

A best evidence topic was written according to a structured protocol. The question addressed was: in patients with inoperable early-stage primary lung cancer does microwave ablation (MWA) or stereotactic ablative body radiotherapy (SBRT) achieve improved outcomes in terms of local control, recurrence, survival and complications? Altogether, more than 550 papers were found using the reported search, of which 12 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. No single study directly compared the effects of MWA with SBRT. However, the best available evidence for MWA (7 studies) was compared to that for SBRT (5 studies). The range of 3-year survival reported for MWA was 29.2–84.7%, compared with 42.7–63.5% for SBRT. The range of median survival was 35–60 months for MWA and 32.6–48 months for SBRT. This suggests similar outcomes between these two 2 techniques. Different side-effect profiles were observed between techniques with MWA associated with pneumothorax and fever and SBRT most commonly causing radiation pneumonitis and rib fractures. The evidence base for MWA is less than that for SBRT and is heterogenous in terms of participants and technical design. However, within these limitations, we conclude that MWA appears comparable with SBRT in terms of local control and survival rates.

Effects of economic downturns on child mortality: a global economic analysis, 1981-2010

Objectives

To analyse how economic downturns affect child mortality both globally and among subgroups of countries of variable income levels.

Design

Retrospective observational study using economic data from the World Bank's Development Indicators and Global Development Finance (2013 edition). Child mortality data were sourced from the Institute for Health Metrics and Evaluation.

Setting

Global.

Participants

204 countries between 1981 and 2010.

Main outcome measures

Child mortality, controlling for country-specific differences in political, healthcare, cultural, structural, educational and economic factors.

Results

197 countries experienced at least 1 economic downturn between 1981 and 2010, with a mean of 7.97 downturns per country (range 0–21; SD 0.45). At the global level, downturns were associated with significant (p<0.0001) deteriorations in each child mortality measure, in comparison with non-downturn years: neonatal (coefficient: 1.11, 95% CI 0.855 to 1.37), postneonatal (2.00, 95% CI 1.61 to 2.38), child (2.93, 95% CI 2.26 to 3.60) and under 5 years of age (5.44, 95% CI 4.31 to 6.58) mortality rates. Stronger (larger falls in the growth rate of gross domestic product/capita) and longer (lasting 2 years rather than 1) downturns were associated with larger significant deteriorations (p<0.001). During economic downturns, countries in the poorest quartile experienced ∼1½ times greater deterioration in neonatal mortality, compared with their own baseline; a 3-fold deterioration in postneonatal mortality; a 9-fold deterioration in child mortality and a 3-fold deterioration in under-5 mortality, than countries in the wealthiest quartile (p<0.0005). For 1–5 years after downturns ended, each mortality measure continued to display significant deteriorations (p<0.0001).

Conclusions

Economic downturns occur frequently and are associated with significant deteriorations in child mortality, with worse declines in lower income countries.

Use of a machine learning algorithm to classify expertise: analysis of hand motion patterns during a simulated surgical task

PURPOSE

To test the hypothesis that machine learning algorithms increase the predictive power to classify surgical expertise using surgeons' hand motion patterns.

METHOD

In 2012 at the University of North Carolina at Chapel Hill, 14 surgical attendings and 10 first- and second-year surgical residents each performed two bench model venous anastomoses. During the simulated tasks, the participants wore an inertial measurement unit on the dorsum of their dominant (right) hand to capture their hand motion patterns. The pattern from each bench model task performed was preprocessed into a symbolic time series and labeled as expert (attending) or novice (resident). The labeled hand motion patterns were processed and used to train a Support Vector Machine (SVM) classification algorithm. The trained algorithm was then tested for discriminative/predictive power against unlabeled (blinded) hand motion patterns from tasks not used in the training. The Lempel-Ziv (LZ) complexity metric was also measured from each hand motion pattern, with an optimal threshold calculated to separately classify the patterns.

RESULTS

The LZ metric classified unlabeled (blinded) hand motion patterns into expert and novice groups with an accuracy of 70% (sensitivity 64%, specificity 80%). The SVM algorithm had an accuracy of 83% (sensitivity 86%, specificity 80%).

CONCLUSIONS

The results confirmed the hypothesis. The SVM algorithm increased the predictive power to classify blinded surgical hand motion patterns into expert versus novice groups. With further development, the system used in this study could become a viable tool for low-cost, objective assessment of procedural proficiency in a competency-based curriculum.

A low-cost surgical application of additive fabrication

OBJECTIVE

This study was used to test the feasibility of using additive fabrication techniques 3-dimensional (3D) printing to create personalized/patient-specific hepatic 3D physical models from clinical radiology studies for surgical resident education.

DESIGN

Patient-specific imaging data from either computed tomography or magnetic resonance imaging scans, in Digital Imaging and Communications in Medicine format, were rendered and manipulated with computer software, translating the medical imaging data sets into useful 3D geometry files in stereo lithography format for 3D printing. A commercial third party was used to print the 3D models in laser sintered nylon, which provided access to expensive, industrial-grade, high-resolution 3-D printers at a low cost.

RESULTS

Multiple patient-specific preoperative 3D physical models were printed of portal and hepatic venous anatomy at a cost of less than $100 per model.

CONCLUSION

Current 3D printing techniques can be used to create low-cost personalized/patient-specific hepatic 3D models from clinical radiology studies for surgical resident education.

Radial artery for coronary artery bypass grafting: does proximal anastomosis to the aorta or left internal mammary artery achieve better patency?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'in coronary artery bypass grafting using radial artery grafts, does proximal anastomosis to the aorta or left internal mammary artery achieve better patency'. Altogether >183 papers were found using the reported search, of which 9 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Radial artery grafts typically have a narrower lumen than vein grafts, and as such there is some concern that anastomosing them directly to the aorta during coronary artery bypass grafting (CABG) may impair graft patency. As such, some surgeons prefer to anastomose radial artery grafts to a second-order vessel such as the left internal mammary artery (LIMA). We sought to assess the evidence for this. A handful of papers directly addressing the issue of the effect of the site of proximal anastomosis on graft patency were found, with three showing no significant difference. One such study reported an insignificant difference in angiographic patency at 32 months postoperatively, with 94.1% of off-aorta grafts remaining patent vs 87.2% of off-LIMA grafts (p = 0.123). However, a large-scale well-designed study was able to demonstrate a statistically significant difference at five years postoperatively, with 74.3% of off-aorta grafts patent, compared with 65.2% of off-LIMA (p = 0.004). Nonetheless, a number of papers that report patency for either off-aorta or off-LIMA grafts give comparable figures for each technique. Additionally, different centres and investigators report very different patency results for grafts that have the same site of proximal anastomosis. One centre was able to achieve patency rates for off-LIMA grafts of 88% up to a mean of 7.7 years postoperatively while another centre reported a patency rate of only 78.6% at three years. Given this, and the plethora of other factors influencing graft patency, we conclude that the best evidence suggests that the site of proximal anastomosis has little or no effect on radial artery graft patency following CABG.

Should trainee doctors use the developing world to gain clinical experience? The annual Varsity Medical Debate - London, Friday 20th January, 2012

The 2012 Varsity Medical Debate between Oxford University and Cambridge University provided a stage for representatives from these famous institutions to debate the motion "This house believes that trainee doctors should be able to use the developing world to gain clinical experience." This article brings together many of the arguments put forward during the debate, centring around three major points of contention: the potential intrinsic wrong of 'using' patients in developing countries; the effects on the elective participant; and the effects on the host community. The article goes on to critically appraise overseas elective programmes, offering a number of solutions that would help optimise their effectiveness in the developing world.

Serum 25-hydroxyvitamin D concentration and mortality from heart failure and cardiovascular disease, and premature mortality from all-cause in United States adults

We aimed to examine associations between serum 25-hydroxyvitamin D (25[OH]D) concentration and mortality from heart failure (HF) and cardiovascular disease (CVD) and premature death from all causes using data from the Third National Health and Nutrition Examination Survey, which included 13,131 participants (6,130 men, 7,001 women) ≥35 years old at baseline (1988 to 1994) and followed through December 2000. Premature death was defined all-cause death at <75 years of age. Results indicated that during an average 8-year follow-up, there were 3,266 deaths (24.9%) including 101 deaths from HF, 1,451 from CVD, and 1,066 premature all-cause deaths. Among HF deaths, 37% of decedents had serum 25(OH)D levels <20 ng/ml, whereas only 26% of those with non-HF deaths had such levels (p <0.001). Multivariate-adjusted Cox model indicated that subjects with serum 25(OH)D levels <20 ng/ml had 2.06 times higher risk (95% confidence interval 1.01 to 4.25) of HF death than those with serum 25(OH)D levels ≥30 ng/ml (p <0.001). In addition, hazard ratios (95% confidence intervals) for premature death from all causes were 1.40 (1.17 to 1.68) in subjects with serum 25(OH)D levels <20 ng/ml and 1.11 (0.93 to 1.33) in those with serum 25(OH)D levels of 20 to 29 ng/ml compared to those with serum 25(OH)D levels ≥30 ng/ml (p <0.001, test for trend). In conclusion, adults with inadequate serum 25(OH)D levels have significantly higher risk of death from HF and all CVDs and all-cause premature death.

What is the potential of oligodendrocyte progenitor cells to successfully treat human spinal cord injury?

Background

Spinal cord injury is a serious and debilitating condition, affecting millions of people worldwide. Long seen as a permanent injury, recent advances in stem cell research have brought closer the possibility of repairing the spinal cord. One such approach involves injecting oligodendrocyte progenitor cells, derived from human embryonic stem cells, into the injured spinal cord in the hope that they will initiate repair. A phase I clinical trial of this therapy was started in mid 2010 and is currently underway.

Discussion

The theory underlying this approach is that these myelinating progenitors will phenotypically replace myelin lost during injury whilst helping to promote a repair environment in the lesion. However, the importance of demyelination in the pathogenesis of human spinal cord injury is a contentious issue and a body of literature suggests that it is only a minor factor in the overall injury process.

Summary

This review examines the validity of the theory underpinning the on-going clinical trial as well as analysing published data from animal models and finally discussing issues surrounding safety and purity in order to assess the potential of this approach to successfully treat acute human spinal cord injury.

Relation between trunk fat volume and reduction of total lung capacity in obese men

Reduction in total lung capacity (TLC) in obese men is associated with restricted expansion of the thoracic cavity at full inflation. We hypothesized that thoracic expansion was reduced by the load imposed by increased total trunk fat volume or its distribution. Using MRI, we measured internal and subcutaneous trunk fat and total abdominal and thoracic volumes at full inflation in 14 obese men [mean age: 52.4 yr, body mass index (BMI): 38.8 (range: 36-44) kg/m(2)] and 7 control men [mean age: 50.1 yr, BMI: 25.0 (range: 22-27.5) kg/m(2)]. TLC was measured by multibreath helium dilution and was restricted (<80% of the predicted value) in six obese men (the OR subgroup). All measurements were made with subjects in the supine position. Mean total trunk fat volume was 16.65 (range: 12.6-21.8) liters in obese men and 6.98 (range: 3.0-10.8) liters in control men. Anthropometry and mean total trunk fat volumes were similar in OR men and obese men without restriction (the ON subgroup). Mean total intraabdominal volume was 9.41 liters in OR men and 11.15 liters in ON men. In obese men, reduced thoracic expansion at full inflation and restriction of TLC were not inversely related to a large volume of 1) intra-abdominal or total abdominal fat, 2) subcutaneous fat volume around the thorax, or 3) total trunk fat volume. In addition, trunk fat volumes in obese men were not inversely related to gas volume or estimated intrathoracic volume at supine functional residual capacity. In conclusion, this study failed to support the hypotheses that restriction of TLC or impaired expansion of the thorax at full inflation in middle-aged obese men was simply a consequence of a large abdominal volume or total trunk fat volume or its distribution.

Effects of intra-gene fitness interactions on the benefit of sexual recombination

Whereas spontaneous point mutation operates on nucleotides individually, sexual recombination manipulates the set of nucleotides within an allele as an essentially particulate unit. In principle, these two different scales of variation enable selection to follow fitness gradients in two different spaces: in nucleotide sequence space and allele sequence space respectively. Epistasis for fitness at these two scales, between nucleotides and between genes, may be qualitatively different and may significantly influence the advantage of mutation-based and recombination-based evolutionary trajectories respectively. We examine scenarios where the genetic sequence within a gene strongly influences the fitness effect of a mutation in that gene, whereas epistatic interactions between sites in different genes are weak or absent. We find that, in cases where beneficial alleles of a gene differ from one another at several nucleotide sites, sexual populations can exhibit enormous benefit compared with asexual populations: not only discovering fit genotypes faster than asexual populations, but also discovering high-fitness genotypes that are effectively not evolvable in asexual populations.

Evolution of changes in carbon monoxide transfer factor in men with chronic obstructive pulmonary disease

Progression of chronic obstructive pulmonary disease (COPD) has been studied predominantly by following change in forced expiratory volume in 1s (FEV1) which reflects both primary airway disease and associated alveolar disease. Carbon monoxide transfer (Tlco) (the product of the transfer coefficient Kco and alveolar volume Va) is the only simple, widely available test of alveolar function, but few studies have followed long-term changes in an individual. Seventeen middle-aged men with moderate chronic airflow obstruction (mean FEV1 56% of predicted values) were observed with yearly measurements of FEV1, Tlco and Kco over a mean of 18.9 yr. At the end of follow-up FEV1 had fallen to 29% of predicted values. Va, measured by single breath dilution, fell in each man. Kco at recruitment ranged from 41% to 110% predicted and remained >75% predicted in eight men at the end of follow-up supporting a phenotype of COPD with predominant airway disease and little emphysema. Fall in FEV1 was faster (2.03% predicted FEV1/yr) in seven men with low initial Kco<75% pred. than in men with initial Kco>75% pred. (1.14% predicted FEV1/yr, P=0.006). Repeated measurements of CO transfer in an individual should increase the present poor knowledge of the contribution of alveolar disease to the progression of chronic airflow obstruction.

Postural changes in nasal and pulmonary resistance in subjects with asthma

INTRODUCTION

Subjects with asthma frequently have nasal symptoms and complain of orthopnoea but airflow resistance is usually only assessed during oral breathing and while seated.

METHOD

We have used a forced oscillation technique to measure total respiratory resistance (Rrs) at 6Hz during mouth breathing (Rrs,mo) and during nose breathing (Rrs,na) in the sitting and supine postures; resistance of the nasal airway (Rnaw) was estimated as Rrs,na--Rrs,mo. Forced oscillations were applied during normal tidal breathing and the mid-tidal lung volume (MTLV) was determined for each breathing route and posture.

SUBJECTS

Three groups of subjects were studied: 10 normal subjects without lung or nasal disease (N; five males, mean age 33.5 [range 23-58] years, mean FEV1 105%pred, FEV1/VC 86%); seven subjects with asthma alone (A; four males, 40.3 [23-57] years, mean FEV1 66%pred, FEV1/VC 74%); 10 asthmatic subjects with nasal obstructive symptoms (AN; six males, 62.8 [38-80] years, mean FEV1 56%pred, FEV1/VC 75%).

RESULTS

In all three groups of subjects, mean Rrs,mo and Rrs,na were higher in the supine than sitting posture. In normal subjects the increase in supine Rrs,mo was associated with a 0.6 liter fall in MTLV. In asthma supine Rrs,mo increased despite a much smaller fall in MTLV; supine increases in Rrs,na were particularly large in presence of nasal disease.

DISCUSSION

Values of airflow resistance are 2-3 times higher in both normal and asthmatic subjects when breathing via the nose and supine than under normal laboratory conditions of oral breathing and seated.

Postural changes in lung volumes and respiratory resistance in subjects with obesity

Reduced functional residual capacity (FRC) is consistently found in obese subjects. In 10 obese subjects (mean +/- SE age 49.0 +/- 6 yr, weight 128.4 +/- 8 kg, body mass index 44 +/- 3 kg/m2) without respiratory disease, we examined 1) supine changes in total lung capacity (TLC) and subdivisions, 2) whether values of total respiratory resistance (Rrs) are appropriate for mid-tidal lung volume (MTLV), and 3) estimated resistance of the nasopharyngeal airway (Rnp) in both sitting and supine postures. The results were compared with those of 13 control subjects with body mass indexes of <27 kg/m2. Rrs at 6 Hz was measured by applying forced oscillation at the mouth (Rrs,mo) or the nose (Rrs,na); Rnp was estimated from the difference between sequential measurements of Rrs,mo and Rrs,na. All measurements were made when subjects were seated and when supine. Obese subjects when seated had a restrictive defect with low TLC and FRC-to-TLC ratio; when supine, TLC fell 80 ml and FRC fell only 70 ml compared with a mean supine fall of FRC of 730 ml in control subjects. Values of Rrs,mo and Rrs,na at resting MTLV in obese subjects were about twice those in control subjects in both postures. Relating total respiratory conductance (1/Rrs) to MTLV, the increase in Rrs,mo in obese subjects was only partly explained by their reduced MTLV. Rnp was increased in some obese subjects in both postures. Despite the increased extrapulmonary mass load in obese subjects, further falls in TLC and FRC when supine were negligible. Rrs,mo at isovolume was increased. Further studies are needed to examine the causes of reduced TLC and increases in Rrs,mo and sometimes in Rnp in obese subjects.

Multiphasic Helical CT Criteria for Differentiation of Recurrent Neoplasm and Desmoplastic Reaction after Laparoscopic Resection of Renal Mass Lesions

BACKGROUND AND PURPOSE

Differentiation of recurrent neoplasm and desmoplastic reaction following laparoscopic resection of renal mass lesions poses a problem. The usefulness of multiphasic helical CT-generated criteria based on enhancement and morphologic characteristics was investigated.

PATIENTS AND METHODS

The findings in 5 female and 12 male patients aged 29 to 68 years having renal-cell carcinoma (11-38 mm; N = 15) or solitary angiomyolipomas (N = 2) treated by laparoscopic resection (N = 15) or open segmental surgery (N = 2) were analyzed. Multiphasic helical CT was performed in the preenhancement, arterial corticomedullary, parenchymal, and excretory phases generating 2.5- to 7-mm slices.

RESULTS

Both recurrent neoplasms showed median postcontrast enhancement of 119 HU in the arterial corticomedullary phase; the median enhancement of desmoplastic masses was 48 HU. In the parenchymal and excretory phase, recurrent neoplasms showed progressive loss of enhancement, whereas desmoplastic lesions sustained enhancement at about the same level. Recurrent neoplasms presented a defined mass with characteristic spiculation, whereas desmoplastic reaction was characterized by an ill-defined mass with spidery projections extending to abutting fat and residual fascial planes. On 2- to 3-month follow-up scans, recurrent neoplasms showed progressive increases in size and desmoplastic reaction a sharp decrease.

CONCLUSION

Enhancement of the mass at the operative site on arterial corticomedullary-phase CT to >90 HU strongly suggests recurrent renal-cell carcinoma, while progressive decrease in size on 1- to 3-month follow-up CT suggests a desmoplastic reaction.

Multiphasic Helical CT Diagnosis of Early Medullary and Papillary Necrosis

PURPOSE

The feasibility of identifying early manifestations of renal papillary necrosis (RPN) and medullary necrosis (RMN) on multiphasic helical CT, leading to prompt treatment for the causative conditions, and its impact on reducing the incidence of late-stage RML and RPN, was investigated.

PATIENTS AND METHODS

Sixty-eight patients (35 male, 33 female) aged 19 to 88 years were examined by multiphasic helical CT for complaints of microscopic hematuria (N=49), macroscopic hematuria (N=2), bacteriuria (N=45), pyuria (N=10), fever (N=15), and flank pain (N=27). Preenhancement, arterial corticomedullary, parenchymal, and excretory phase scans generated 1.25 to 7-mm-thick slices. Follow-up CTs were performed at 1 month (N=62) and 3 months (N=58).

RESULTS

While the attenuation coefficients of areas suspect for RMN and RPN were similar on preenhancement CT, they differed substantially on the arterial corticomedullary phase (lesions 55 HU mean; normal medulla 120 HU mean) and parenchymal phase (lesions 58 HU mean, normal medulla 210 HU mean). Investigation for predisposing conditions identified diabetes in 18 patients, upper urinary-tract infections in 48, sickle-cell disease or trait in 17, urinary obstruction in 7, and cirrhosis of the liver in 1. On follow-up examinations, enhancement had normalized in 26 compromised areas of 14 patients at 1 month, and 47 areas (23 patients) at 3 months, remained stationary in 28 patients at 1 month and 9 at 3 months, and progressed in 20 at 1 and 26 at 3 months (P<0.001; Fisher's exact test). Patients (N=35) treated for underlying conditions causing ischemia showed reperfusion in 12 cases at 1 month and 20 at 3 months, while of the untreated patients (N=10), none showed reperfusion, and all lesions increased in size.

CONCLUSIONS

Multiphasic helical CT is recommended for identification of RMN and RPN at a stage when effective treatment of underlying causative conditions can arrest or reverse the process of devascularization and prevent loss of medullary tissue.

Detection of medullary and papillary necrosis at an early stage by multiphasic helical computerized tomography

PURPOSE

Multiphasic helical computerized tomography (CT) is advocated to identify early manifestations of papillary and medullary necrosis based on decreased enhancement of circumscribed areas in the medullary pyramid. At this stage the devascularizing process can be reversed if causative conditions such as infections or diabetes mellitus are effectively treated.

MATERIALS AND METHODS

Multiphasic helical CTs were performed in 31 male and 26 female patients with complaints of microscopic hematuria (41), macroscopic hematuria (2), bacteriuria (39) and pyuria (9). Pre-enhancement, arterial, early corticomedullary, parenchymal and excretory phase helical CTs generated 1.25 to 5 mm. thick slices. Followup examination included multiphasic helical CT at 1 and 3 months, and excretory urography for some patients at 3 months.

RESULTS

Bacteriuria was identified as the probable cause of medullary and papillary necrosis in 39 patients, of whom 28 were treated with effective antibiotic therapy, resulting in normalization and re-perfusion of the initial lesion in 16, no change in 5 and progressive disease in 7 at 3-month followup. Of 8 lesions not treated with specific antibiotic therapy 4 progressed and 4 remained unchanged.

CONCLUSIONS

Multiphasic helical CT unlike the excretory urogram can identify medullary and papillary necrosis at an early stage when effective treatment of the underlying cause can reverse the process of devascularization and prevent sloughing of medullary tissues.

Chemo-ablation of the prostate with dehydrated alcohol for the treatment of prostatic obstruction

PURPOSE

We confirmed clinically whether chemo-ablation of the prostate with absolute ethanol may be an innovative transurethral approach for the relief of obstructive benign prostatic hyperplasia.

METHODS

Using the InjecTx endoscopic device (Injectx Inc., San Jose, California) an initial cohort of 15 patients, including 13 who have now been followed more than 1 year, underwent elective transurethral chemo-ablation of the prostate.

RESULTS

Preoperative and postoperative comparisons of the American Urological Association symptom score, maximum urine flow rate and prostatic volume reveal significant improvement with minimal discomfort and no major complication.

CONCLUSIONS

The InjecTx technique proved encouragingly successful in this initial small-scale clinical trial.

Endourologic management of malignant ureteral strictures

PURPOSE

This retrospective analysis assessed the efficacy of balloon dilatation, endoureterotomy, percutaneous ureteroneocystostomy with stenting, and insertion of Wallstents in the management of malignant ureteral strictures with an intact or compromised vascular supply.

PATIENTS AND METHODS

A series of 127 patients with ureteral strictures secondary to malignancies were assessed after at least 2-year follow-up (range 2-5 years; mean 3.5 years). Balloon dilation (antegrade approach) was applied in 46 patients, endoureterotomy with temporary stenting in 37, percutaneous ureteroneocystostomy with stenting in 34, bougie and stents in 13, and Wallstents in 31.

RESULTS

Balloon dilatation was successful in only two of four malignant midureteral stenoses with intact vascular supplies and was even less successful (10%) in midureteral strictures with a compromised vascular supply. Endoureterotomy failed in all cases to prevent ureteral obstruction. Percutaneous ureteroneocystostomy achieved patency in 11 of 34 patients (33%) having a compromised ureteral vascular supply. Wallstents were successful in 18 of 31 patients (58%) with stenoses of the pelvic ureter.

CONCLUSIONS

Percutaneous ureteroneocystostomy with stenting meets the requirement for palliation in patients with obstruction secondary to pelvic neoplasms. Wallstents proved to be most successful when used in the pelvic ureter.

Endourologic management of benign ureteral strictures with and without compromised vascular supply

OBJECTIVES

To retrospectively assess the efficacy of balloon dilation, endopyelotomy/ureterotomy, and stenting alone in the management of benign ureteral strictures with intact or compromised vascular supply.

METHODS

One hundred fourteen patients with benign ureteral strictures were assessed after at least a 2-year follow-up (range 2 to 16 years, mean 6.3). Balloon dilation was performed in 81, endopyelotomy/ureterotomy with temporary stenting in 27, and ureteral stenting alone in 6 patients. Ureteral strictures were divided into strictures with intact or with compromised vascular supply.

RESULTS

Balloon dilation was successful in short ureteral strictures with intact vascular supply in 33 of 37 (89.2%), but only in 3 of 8 (37.5%) long ureteral strictures and in 1 of 2 (50%) recurrent ureteropelvic junction strictures. Balloon dilation was less successful when the vascular supply was compromised in 2 (40%) of 5 short strictures, 1 (16.7%) of 6 long strictures, and 2 (33.3%) of 6 recurrent ureteropelvic junction strictures. Endopyelotomy/ureterotomy was successful in 17 (89.5%) of 19 strictures with compromised vascular supply.

CONCLUSIONS

Balloon dilation is recommended for management of short strictures with intact vascular supply. Endoureterotomy with stenting is recommended for all long ureteral strictures, for ureteropelvic junction stenoses, and for short ureteral strictures with compromised vascular supply and benign underlying etiology.

Accuracy of diagnosis by guided biopsy of renal mass lesions classified indeterminate by imaging studies

OBJECTIVES

To define the accuracy, safety, and impact of percutaneous biopsies of indeterminate mass lesions as an additional diagnostic tool. The vast majority of renal mass lesions are routinely diagnosed by radiographic features alone. However, with the increased use of computed tomography scanning and ultrasound, many smaller renal masses, which are "indeterminate" (refractory to categorization on the basis of imaging alone), are now being discovered.

METHODS

We retrospectively reviewed 583 patients (364 male and 219 female) with indeterminate renal mass lesions diagnosed by imaging studies that were further investigated by percutaneous biopsy. Patients were followed up for at least 5 years if the biopsy result demonstrated a benign lesion, or they underwent surgical exploration if the biopsy result demonstrated a malignancy. Biopsy or aspiration material was assessed by histopathologic and cytologic evaluation and, when appropriate, with biochemistry, Gram stain, culture, and sensitivity. The biopsy site was localized by computed tomography, ultrasound, or fluoroscopy.

RESULTS

Five hundred eighty-three patients with indeterminate renal mass lesions (representing 7.2% of all renal masses diagnosed from 1967 through 1996) were diagnosed by imaging studies complemented by guided biopsy. Sixty-six patients were lost to follow-up, leaving 517 patients who were analyzed. In 393 cases (76%), the imaging-guided biopsy provided a definitive diagnosis. The incidence of false diagnoses was 1.2% (7 biopsies). In 124 of the cases (21%), imaging-guided biopsy was unable to determine the etiology of the lesion with acceptable confidence; of these, 21 biopsies did not provide enough material to establish the diagnosis (16.9%).

CONCLUSIONS

Overall, percutaneous biopsy of the kidney has proved to be a safe and accurate diagnostic procedure, with impact on the management of cystic or solid renal lesions.

Penile Kaposi's sarcoma preceded by chronic penile lymphoedema

Kaposi's sarcoma localized to the penis with striking lymphoedema is extraordinary. We report a middle-aged Haitian man who was human herpesvirus-8 seropositive, without evidence of immunosuppression or human immunodeficiency virus infection. He was first seen with Kaposi's sarcoma of 6 months duration localized to his penis, preceded by a 3-year history of chronic penile lymphoedema. His tumour regressed completely after radiotherapy. We propose that chronic lymphoedema in this patient predisposed to the development of Kaposi's sarcoma.

Cross-Correlation of Tenerife Data with Galactic Templates-Evidence for Spinning Dust?

The recent discovery of dust-correlated diffuse microwave emission has prompted two rival explanations: free-free emission and spinning dust grains. We present new detections of this component at 10 and 15 GHz by the switched-beam Tenerife experiment. The data show a turnover in the spectrum and thereby support the spinning dust hypothesis. We also present a significant detection of synchrotron radiation at 10 GHz, which is useful for normalizing foreground contamination of cosmic microwave background experiments at high galactic latitudes.

Percutaneous nephrostomy as adjunct management in advanced upper urinary tract infection

OBJECTIVES

To determine by retrospective review of 315 percutaneous nephrostomies, performed for pyonephrosis, whether this intervention has major clinical advantages.

METHODS

From 1977 to 1996, under the direct supervision of the senior author of this report (E.K.L.), at seven hospital sites, 315 patients (181 males, 134 females; 17 to 88 years of age) were treated with percutaneous nephrostomy and antibiotic therapy for infected hydronephrosis.

RESULTS

Additional or disparate pathogens were identified in 116 (36.8%) of 315 patients, leading to a clinically significant change in, or addition of, antibiotics and/or antifungal agents in 84 (73%) of 116. Most notably, we often found a clinically important disparity between the results of cultures obtained from the nephrostomy and those obtained from bladder-urine specimens.

CONCLUSIONS

This retrospective review confirms previously reported advantages of percutaneous upper urinary tract drainage as a potentially life-saving adjunct in the treatment of pyonephrosis. Several case studies highlight the advantage of this maneuver in difficult cases involving obstruction due to extensive fungus or debris. In particular, our review focuses attention on the clinically important insight that urine cultures from percutaneous nephrostomy drainage often identify pathogens that differ from those detected in concurrent bladder cultures.

Placement of metallic stents in ureters obstructed by carcinoma of the cervix to maintain renal function in patients undergoing long-term chemotherapy

OBJECTIVE

Metallic stents, sometimes augmented by "J" endostents, were placed in ureters obstructed by advanced carcinoma of the cervix to improve or maintain renal function in these patients at a level necessary to pursue long-term chemotherapy and radiation therapy.

SUBJECTS AND METHODS

Seventeen ureters in 11 patients were treated with metallic stents, which were placed by an anterograde approach in 10 patients and by a retrograde approach in one. An anterograde ureteroneocystostomy was necessary in two of the 11 patients. J endostents were placed for I month in all patients. In 10 ureters, J endostents were reintroduced during follow-up 1-48 months later.

RESULTS

In 17 ureters, metallic stents were successfully placed; in the remaining three ureters, the procedures were aborted because of technical difficulties. The goal of improving and maintaining renal function was met in 10 patients. Serum creatinine levels returned to normal in four patients and stabilized at a range of 2.7-3.2 mg/dl in six more patients, permitting treatment with chemotherapy, radiation therapy, or both. Four of the 11 patients died within 4 months after treatment, and three more died within 2 years. At the time of death or last follow-up, seven metallic stents and eight combinations of metallic stents and J endostents were patent. Complications were minor.

CONCLUSION

Placement of metallic stents is recommended as an effective method to ensure patency and to facilitate cystoscopic replacement of J endostents in ureters compromised by carcinoma of the cervix. Renal function can be maintained, allowing chemotherapy. Survival is governed by the effectiveness of chemotherapy and radiation therapy.

Use of mouth pressure twitches induced by cervical magnetic stimulation to assess voluntary activation of the diaphragm

There is a need for a simple method to assess the adequacy of diaphragm activation during voluntary inspiratory efforts in patients with suspected respiratory muscle weakness. We have compared mouth (Pmo,t), oesophageal (Poes,t) and transdiaphragmatic (Pdi,t) twitch pressure elicited by cervical magnetic stimulation (CMS) in five normal men (mean (SD) age 32.2 (1.8) yrs) on two separate study days. Single magnetic stimuli were delivered at functional residual capacity during relaxation and during graded voluntary inspiratory efforts against a closed airway. As voluntary-effort transdiaphragmatic and oesophageal pressure increased, Pdi,t and Poes,t decreased linearly (r range, respectively, 0.82-0.98 and 0.87-0.95). During relaxation, Pmo,t was unreliable due to the poor transmission of intrathoracic pressure, but during inspiratory efforts, the relation between voluntary mouth pressure and Pmo,t was also linear (r range 0.84-0.95). On average, our subjects voluntarily generated 99, 100 and 102% of the maximum transdiaphragmatic, oesophageal and mouth pressures predicted by the respective linear regression equations. Pmo,t was correlated to both Poes,t and Pdi,t during inspiratory efforts, but not during relaxation. These studies confirm that twitch pressures induced by CMS during inspiratory efforts can be assessed at the mouth in normal subjects, providing a simple and non-invasive technique for assessing diaphragm activation during voluntary inspiratory efforts. Potentially, this technique could be made more sensitive and accurate and applied to detect submaximal efforts in patients.