Islet transplantation outcomes in type 1 diabetes and transplantation of HLA-DQ8/DR4: results of a single-centre retrospective cohort in Canada

Background

In solid organ transplantation, HLA matching between donor and recipient is associated with superior outcomes. In islet transplantation, an intervention for Type 1 diabetes, HLA matching between donor and recipient is not performed as part of allocation. Susceptibility to Type 1 diabetes is associated with the presence of certain HLA types. This study was conducted to determine the impact of these susceptibility antigens on islet allograft survival.

Methods

This is a single-centre retrospective cohort study. This cohort of transplant recipients (n = 268) received islets from 661 donor pancreases between March 11th, 1999 and August 29th, 2018 at the University of Alberta Hospital (Edmonton, AB, Canada). The frequency of the Type 1 diabetes susceptibility HLA antigens (HLA-A24, -B39, -DQ8, -DQ2 and-DQ2-DQA1∗05) in recipients and donors were determined. Recipient and donor HLA antigens were examined in relation to time to first C-peptide negative status/graft failure or last observation point. Taking into account multiple transplants per patient, we fitted a Gaussian frailty survival analysis model with baseline hazard function stratified by transplant number, adjusted for cumulative islet dose and other confounders.

Findings

Across all transplants recipients of donors positive for HLA-DQ8 had significantly better graft survival (adjusted HRs 0.33 95% CI 0.17-0.66; p = 0.002). At first transplant only, donors positive for HLA-DQ2-DQA1∗05 had inferior graft survival (adjusted HR 1.96 95% CI 1.10-3.46); p = 0.02), although this was not significant in the frailty analysis taking multiple transplants into account (adjusted HR 1.46 95% CI 0.77-2.78; p = 0.25). Other HLA antigens were not associated with graft survival after adjustment for confounders.

Interpretation

Our findings suggest islet transplantation from HLA-DQ8 donors is associated with superior graft outcomes. A donor positive for HLA-DQ2-DQA1∗05 at first transplant was associated with inferior graft survival but not when taking into account multiple transplants per recipient. The relevance of HLA-antigens on organ allocation needs further evaluation and inclusion in islet transplant registries and additional observational and interventional studies to evaluate the role of HLA-DQ8 in islet graft survival are required.

Funding

None.

Periductal Stromal Tumor of the Breast with a TERT Promoter Mutation: First Case Report with Comprehensive Molecular Analysis

The molecular pathogenesis of breast fibroepithelial tumors continues to be elucidated. Recently, highly recurrent MED12 mutations arising in exon 2 at codon 44 were discovered in fibroadenomas and phyllodes tumors. In addition, a high prevalence of TERT promoter mutations in two hotspots (124 and 126 bp upstream from the translation start site) was discovered in up to 65% of phyllodes tumors. Breast periductal stromal tumors are a potentially distinct category of fibroepithelial lesions that are exceptionally rare with controversial classification and pathogenesis. Herein, we report the first comprehensive molecular genetic workup of a breast periductal stromal tumor that harbored a TERT promoter -124C > T mutation, supporting a relation to phyllodes tumors.

Examining the equity and diversity characteristics of academic general surgeons hired in Canada

BACKGROUND

Job competition and underemployment among surgeons emphasize the importance of equitable hiring practices. The purpose of this study was to describe some of the demographic characteristics of academic general surgeons and to evaluate the gender and visible minority (VM) status of those recently hired.

METHODS

Demographic information about academic general surgeons across Canada including gender, VM status, practice location and graduate degree status was collected. Location of residency was collected for recently hired general surgeons (hired between 2013 and 2020). Descriptive statistics were performed on the demographic characteristics at each institution. Pearson correlation coefficients and hypothesis testing were used to determine the correlation between various metrics and gender and VM status.

RESULTS

A total of 393 general surgeons from 30 academic hospitals affiliated with 14 universities were included. The percentage of female general surgeons ranged from 0% to 47.4% and the percentage of VM general surgeons ranged from 0% to 66.7% at the hospitals. This heterogeneity did not correlate with city population (gender: r = 0.06, p = 0.77; VM: r = 0.04, p = 0.83). The percentage of VM general surgeons at each hospital did not correlate with the percentage of VM population in the city (r = 0.13, p = 0.49). Only 34 of 120 recently hired academic general surgeons (28.3%) did not have a graduate degree. The percentage of recently hired academic general surgeons who did not have a graduate degree was approximately 1.5 times higher among male hirees than female hirees. With respect to academic promotion, the percentage of female full professors ranged from 0% to 40.0% and did not correlate with the percentage of female general surgeons at each institution (r = 0.11, p = 0.70). The percentage of VM full professors ranged from 0% to 44.4% and was moderately correlated with the percentage of VM surgeons at each institution (r = 0.40, p = 0.16).

CONCLUSION

The academic general surgery workforce appears to be somewhat diverse. However, there was substantial heterogeneity in diversity between hospitals, leaving room for improvement. We must be willing to examine our hiring processes and be transparent about them to build an equitable surgical workforce.

Dermatology ethics and health equity elective: a model for incorporating cultural diversity into undergraduate medical education

This letter concerns the discussion on expanding education on diversity and ethical issues in dermatology. As documented in previous literature, undergraduate medical education (UME) in dermatology lacks content on historical inequities, sexual and gender diversity, and skin of colour. We propose using a preclinical elective to create a more diverse dermatology UME, particularly when there is limited space for expansion in the core curriculum.

HMGB1 acts as an agent of host defense at the gut mucosal barrier

Mucosal barriers provide the first line of defense between internal body surfaces and microbial threats from the outside world. ¹ In the colon, the barrier consists of two layers of mucus and a single layer of tightly interconnected epithelial cells supported by connective tissue and immune cells. ² Microbes colonize the loose, outer layer of colonic mucus, but are essentially excluded from the tight, epithelial-associated layer by host defenses. ³ The amount and composition of the mucus is calibrated based on microbial signals and loss of even a single component of this mixture can destabilize microbial biogeography and increase the risk of disease. ^4-7 However, the specific components of mucus, their molecular microbial targets, and how they work to contain the gut microbiota are still largely unknown. Here we show that high mobility group box 1 (HMGB1), the prototypical damage-associated molecular pattern molecule (DAMP), acts as an agent of host mucosal defense in the colon. HMGB1 in colonic mucus targets an evolutionarily conserved amino acid sequence found in bacterial adhesins, including the well-characterized Enterobacteriaceae adhesin FimH. HMGB1 aggregates bacteria and blocks adhesin-carbohydrate interactions, inhibiting invasion through colonic mucus and adhesion to host cells. Exposure to HMGB1 also suppresses bacterial expression of FimH. In ulcerative colitis, HMGB1 mucosal defense is compromised, leading to tissue-adherent bacteria expressing FimH. Our results demonstrate a new, physiologic role for extracellular HMGB1 that refines its functions as a DAMP to include direct, virulence limiting effects on bacteria. The amino acid sequence targeted by HMGB1 appears to be broadly utilized by bacterial adhesins, critical for virulence, and differentially expressed by bacteria in commensal versus pathogenic states. These characteristics suggest that this amino acid sequence is a novel microbial virulence determinant and could be used to develop new approaches to diagnosis and treatment of bacterial disease that precisely identify and target virulent microbes.

Long term outcomes after normothermic machine perfusion in liver transplantation -experience at a single North American centre

Normothermic machine perfusion (NMP) has emerged as a valuable tool in the preservation of liver allografts before transplantation. Randomized trials have shown that replacing static cold storage (SCS) with NMP reduces allograft injury and improves graft utilization. The University of Alberta's liver transplant program was one of the early adopters of NMP in North America. Herein, we describe our seven-year experience applying NMP to extend preservation time in liver transplantation using a 'back-to-base' approach. From 2015 to 2021, 79 livers were transplanted following NMP compared to 386 after SCS only. NMP livers were preserved for a median time of 847min compared to 288.5min in the SCS cohort (p<0.0001). Despite this, we observed significantly improved 30-day graft survival (p=0.030), though no differences in long term patient survival, major complications or biliary or vascular complications. We also found that while SCS time was strongly associated with increased graft failure at one year in the SCS cohort (p=0.006), there was no such association amongst NMP livers (p=0.171). Our experience suggests that NMP can safely extend the total preservation time of liver allografts without increasing complications.

Pancreas and Islet Transplantation: Comparative Outcome Analysis of a Single-centre Cohort Over 20-years

OBJECTIVE

To provide the largest single-center analysis of islet (ITx) and pancreas (PTx) transplantation.

SUMMARY BACKGROUND DATA

Studies describing long-term outcomes with ITx and PTx are scarce.

METHODS

We included adults undergoing ITx (n=266) and PTx (n=146) at the University of Alberta from January 1999 to October 2019. Outcomes include patient and graft survival, insulin independence, glycemic control, procedure-related complications, and hospital readmissions. Data are presented as medians (interquartile ranges, IQR) and absolute numbers (percentages, %) and compared using Mann-Whitney and χ2 tests. Kaplan-Meier estimates, Cox proportional hazard models and mixed main effects models were implemented.

RESULTS

Crude mortality was 9.4% and 14.4% after ITx and PTx, respectively ( P= 0.141). Sex-adjusted and age-adjusted hazard-ratio for mortality was 2.08 (95% CI, 1.04-4.17, P= 0.038) for PTx versus ITx. Insulin independence occurred in 78.6% and 92.5% in ITx and PTx recipients, respectively ( P= 0.0003), while the total duration of insulin independence was 2.1 (IQR 0.8-4.6) and 6.7 (IQR 2.9-12.4) year for ITx and PTx, respectively ( P= 2.2×10 -22 ). Graft failure ensued in 34.2% and 19.9% after ITx and PTx, respectively ( P =0.002). Glycemic control improved for up to 20-years post-transplant, particularly for PTx recipients (group, P= 7.4×10 -7 , time, P =4.8×10 -6 , group*time, P= 1.2×10 -7 ). Procedure-related complications and hospital readmissions were higher after PTx ( P =2.5×10 -32 and P= 6.4×10 -112 , respectively).

CONCLUSIONS

PTx shows higher sex-adjusted and age-adjusted mortality, procedure-related complications and readmissions compared with ITx. Conversely, insulin independence, graft survival and glycemic control are better with PTx. This study provides data to balance risks and benefits with ITx and PTx, which could improve shared decision-making.

C-peptide Targets and Patient-centered Outcomes of Relevance to Cellular Transplantation for Diabetes

BACKGROUND

C-peptide levels are a key measure of beta-cell mass following islet transplantation, but threshold values required to achieve clinically relevant patient-centered outcomes are not yet established.

METHODS

We conducted a cross-sectional retrospective cohort study evaluating patients undergoing islet transplantation at a single center from 1999 to 2018. Cohorts included patients achieving insulin independence without hypoglycemia, those with insulin dependence without hypoglycemia, and those with recurrent symptomatic hypoglycemia. Primary outcome was fasting C-peptide levels at 6 to 12 mo postfirst transplant; secondary outcomes included stimulated C-peptide levels and BETA-2 scores. Fasting and stimulated C-peptide and BETA-2 cutoff values for determination of hypoglycemic freedom and insulin independence were evaluated using receiver operating characteristic curves.

RESULTS

We analyzed 192 patients, with 122 (63.5%) being insulin independent without hypoglycemia, 61 (31.8%) being insulin dependent without hypoglycemia, and 9 (4.7%) experiencing recurrent symptomatic hypoglycemia. Patients with insulin independence had a median (interquartile range) fasting C-peptide level of 0.66 nmol/L (0.34 nmol/L), compared with 0.49 nmol/L (0.25 nmol/L) for those being insulin dependent without hypoglycemia and 0.07 nmol/L (0.05 nmol/L) for patients experiencing hypoglycemia ( P < 0.001). Optimal fasting C-peptide cutoffs for insulin independence and hypoglycemia were ≥0.50 nmol/L and ≥0.12 nmol/L, respectively. Cutoffs for insulin independence and freedom of hypoglycemia using stimulated C-peptide were ≥1.2 nmol/L and ≥0.68 nmol/L, respectively, whereas optimal cutoff BETA-2 scores were ≥16.4 and ≥5.2.

CONCLUSIONS

We define C-peptide levels and BETA-2 scores associated with patient-centered outcomes. Characterizing these values will enable evaluation of ongoing clinical trials with islet or stem cell therapies.

COVID-19 Infection and Acute Pancreas Transplant Graft Thrombosis

The coronavirus disease 2019 (COVID-19) pandemic created an unprecedented challenge for healthcare, and the world continues to struggle in recovering from its aftermath. COVID-19 has been clearly linked to hypercoagulable states and can lead to end-organ ischemia, morbidity, and mortality. Immunosuppressed solid organ transplant recipients represent a highly vulnerable population for the increased risk of complications and mortality. Early venous or arterial thrombosis with acute graft loss after whole pancreas transplantation is well-described, but late thrombosis is rare. We herein report a case of acute, late pancreas graft thrombosis at 13 years post pancreas-after-kidney (PAK) transplantation coinciding with an acute COVID-19 infection in a previously double-vaccinated recipient.

Pancreatic islet transplantation in type 1 diabetes: 20-year experience from a single-centre cohort in Canada

BACKGROUND

Islet transplantation offers an effective treatment for selected people with type 1 diabetes and intractable hypoglycaemia. Long-term experience, however, remains limited. We report outcomes from a single-centre cohort up to 20 years after islet transplantation.

METHODS

This cohort study included patients older than 18 years with type 1 diabetes undergoing allogeneic islet transplantation between March 11, 1999, and Oct 1, 2019, at the University of Alberta Hospital (Edmonton, AB, Canada). Patients who underwent islet-after-kidney transplantation and islet transplantation alone or islet transplantation before whole-pancreas transplantation (follow-up was censored at the time of whole-pancreas transplantation) were included. Patient survival, graft survival (fasting plasma C-peptide >0·1 nmol/L), insulin independence, glycaemic control, and adverse events are reported. To identify factors associated with prolonged graft survival, recipients with sustained graft survival (≥90% of patient follow-up duration) were compared with those who had non-sustained graft survival (<90% of follow-up duration). Multivariate binary logistic regression analyses were done to determine predictors of sustained graft survival.

FINDINGS

Between March 11, 1999, and Oct 1, 2019, 255 patients underwent islet transplantation and were included in the analyses (149 [58%] were female and 218 [85%] were White). Over a median follow-up of 7·4 years (IQR 4·4-12·2), 230 (90%) patients survived. Median graft survival was 5·9 years (IQR 3·0-9·5), and graft failure occurred in 91 (36%) patients. 178 (70%) recipients had sustained graft survival, and 77 (30%) had non-sustained graft survival. At baseline, compared with patients with non-sustained graft survival, those with sustained graft survival had longer median type 1 diabetes duration (33·5 years [IQR 24·3-41·7] vs 26·2 years [17·0-35·5]; p=0·0003), median older age (49·4 years [43·5-56·1] vs 44·2 years [35·4-54·2]; p=0·0011), and lower median insulin requirements (0·53 units/kg per day [0·45-0·67] vs 0·59 units/kg per day [0·48-0·70]; p=0·032), but median HbA_1c concentrations were similar (8·2% [7·5-9·0] vs 8·5% [7·8-9·2]; p=0·23). 201 (79%) recipients had insulin independence, with a Kaplan-Meier estimate of 61% (95% CI 54-67) at 1 year, 32% (25-39) at 5 years, 20% (14-27) at 10 years, 11% (6-18) at 15 years, and 8% (2-17) at 20 years. Patients with sustained graft survival had significantly higher rates of insulin independence (160 [90%] of 178 vs 41 [53%] of 77; p<0·0001) and sustained improvements in glycaemic control mixed-main-effects model group effect, p<0·0001) compared with those with non-sustained graft survival. Multivariate analyses identified the combined use of anakinra plus etanercept (adjusted odds ratio 7·5 [95% CI 2·7-21·0], p<0·0001) and the BETA-2 score of 15 or higher (4·1 [1·5-11·4], p=0·0066) as factors associated with sustained graft survival. In recipients with sustained graft survival, the incidence of procedural complications was lower (23 [5%] of 443 infusions vs 17 [10%] of 167 infusions; p=0·027), whereas the incidence of cancer was higher (29 of [16%] of 178 vs four [5%] of 77; p=0·015) than in those with non-sustained graft survival; most were skin cancers (22 [67%] of 33). End-stage renal disease and severe infections were similar between groups.

INTERPRETATION

We present the largest single-centre cohort study of long-term outcomes following islet transplantation. Although some limitations with our study remain, such as the retrospective component, a relatively small sample size, and the absence of non-transplant controls, we found that the combined use of anakinra plus etanercept and the BETA-2 score were associated with improved outcomes, and therefore these factors could inform clinical practice.

FUNDING

None.

Acoustic and vibration isolation for a gravity gradiometer

Vibration in the audio frequency band affects the performance of rotating gravity gradiometers used for airborne mineral exploration. This is probably due to translation to rotation coupling inside the gradiometer platform. It was found that the DC gravity gradient signal was proportional to the square of the third time derivative of position, or jerk squared. The demanding airborne environment for such instrumentation demands a light weight broadband acoustic shield and vibration isolator. This paper presents the design principles for such an isolator, based on vibration isolated spherical shell structures. Performance data are presented as well as flight test data that demonstrated a 14% gravity gradient noise reduction compared with an unshielded instrument.

Public health service increased risk donor kidney grafts for transplant into children, a survey of pediatric nephrologists

BACKGROUND

Kidney transplant is the best treatment for end-stage renal disease (ESRD); however, access is limited by severe organ shortage. Public Health Service increased risk donors (PHS-IRD) represent a significant portion of available organs which are discarded at disproportional rates.

METHODS

Pediatric nephrologists were surveyed regarding PHS-IRD kidneys to understand attitudes and perceived barriers to the use of these grafts in children. We sought to elucidate what methods may help increase the likelihood of PHS-IRD acceptance.

RESULTS

Twenty-two responses were received from United States pediatric nephrologists representing 11 UNOS regions (response rate 5.9%). Of respondents, 50% had been practicing for 20+ years, 77% in academic hospitals, and 63% in cities with over 1 000 000 people. All respondents worked in an institution with a kidney transplant program. 41% reported that they would not accept PHS-IRD kidneys under any circumstance, 45% would accept depending on the candidate's medical status, and 14% routinely accepted PHS-IRD kidneys. Infectious transmission was the biggest disincentive reported (59%), with only 55% of respondents feeling comfortable counseling families on the associated risks. 82% of respondents did not perceive all PHS-IRD as the same, and 90% supported stratifying PHS-IRD into tiers based on risk, which would increase the likelihood of organ acceptance (82%) and assist in counseling families (91%).

CONCLUSIONS

With improved utilization, PHS-IRD kidneys offer a step toward decreasing the organ shortage. These findings suggest hesitance in use of PHS-IRD kidneys for pediatric recipients. Further stratification of risk could aid in provider organ acceptance and counseling patients.

Breeding systems of floral colour forms in the Drosera cistiflora species complex

Variation in plant breeding systems has implications for pollinator-mediated selection on floral traits and the ecology of populations. Here we evaluate pollinator contribution to seed production, self-compatibility and pollen limitation in different floral colour forms of Drosera cistiflora sensu lato (Droseraceae). These insectivorous perennial plants are endemic to fynbos and renosterveld vegetation in the Cape Floristic Region of South Africa, and the species complex includes five floral colour forms (pink, purple, red, white and yellow), some of which are known to be pollinated by beetles. Controlled hand-pollination experiments were conducted in 15 populations of D. cistiflora s.l. (two to four populations per floral colour form) to test whether the colour forms vary in their degree of self-compatibility and their ability to produce seeds through autonomous self-fertilization. Yellow-flowered forms were highly self-incompatible, while other floral colour forms exhibited partial self-compatibility. Seed set resulting from autonomous selfing was very low, and pollinator dependence indices were high in all populations. Since hand cross-pollination resulted in greater seed set than open pollination in 13 of the 15 populations, we inferred that seed production is generally pollen-limited. Drosera cistiflora s.l. typically exhibits high levels of pollinator dependence and pollen limitation. This is unusual among Drosera species worldwide and suggests that pollinators are likely to mediate strong selection on attractive traits such as floral colour and size in D. cistiflora s.l. These results also suggest that the floral colour forms of D. cistiflora s.l. which are rare and threatened are likely to be vulnerable to local extinction if mutualisms were to collapse indefinitely.

Interlaboratory Study of a Thermospray-Liquid Chromatographic/Mass Spectrometric Method for Selected N-Methyl Carbamates, N-Methyl Carbamoyloximes, and Substituted Urea Pesticides

A thermospray-liquid chromatographic/mass spectrometric (TS-LC/MS) method was evaluated in an interlaboratory study for determining 3 N-methyl carbamates (bendiocarb, carbaryl, and carbofuran), 3 N-methyl carbamoyloximes (aldicarb, methomyl, and oxamyl), 2 substituted urea pesticides (diuron and linuron), and 1 ester of a substituted carbamic acid (carbendazim). The purpose of this study was to establish whether these 9 compounds can be reliably detected and quantitated with this method, and to establish the interlaboratory precision and accuracy of the method with currently available instrumentation. The study design was based on AOAC INTERNATIONAL’S blind replicate design with balanced replicates. The samples consisted of solutions of the 9 test compounds in methanol at 3 concentrations that were unknown to the participating laboratories and that covered the linear range of the method. Nine volunteer laboratories participated in the study. Linear regression equations are presented that calculate the accuracy of the method, i.e., the percent recovery of each of the 9 compounds at any concentration within the range of concentrations tested (5–90 (μg/mL for each compound, except carbendazim, for which the range was 1.25–22.5 μg/mL). The intra laboratory precisions of the TS-LC/MS method ranged from 6.5 to 33.1 % relative standard deviation, depending on the compound. The interlaboratory method precisions ranged from 29.8 to 98.2% relative standard deviation over the concentration range tested. Analysis of variance indicates that for all compounds tested, the variation from laboratory to laboratory is greater than that attributed to analytical error displayed within laboratories. There are many operational parameters that could contribute to interlaboratory variability; one of them, the thermospray tip temperature, can play a major role in adduct formation and ion fragmentation in the case of thermally labile carbamate pesticides and, therefore, needs to be monitored and controlled carefully. The correlation of mass spectral data with the thermospray tip temperature was attempted using principal component analysis.

Double Obstruction Following Third Renal Transplant: A Case Report

As the field of transplant evolves and patients with chronic disease live longer, retransplant for end-stage renal disease becomes more common because kidney allografts have a limited lifespan. In renal retransplant, graft and patient survival is near equivalent to first-time transplant; however, these procedures present a unique surgical risk profile, especially third and subsequent transplants, which are reviewed in this manuscript. The risk of bowel obstruction in primary kidney transplant recipients is much lower than patients who have undergone laparotomy for second or third transplant because of the retroperitoneal location of the transplanted kidney. Internal hernia is an uncommon cause of small bowel obstruction, particularly after kidney transplant, and often diagnosis and intervention are delayed because of diagnostic uncertainty. We report a case of a 34-year-old man with acute kidney injury and bowel obstruction, whose final diagnosis was an internal hernia around the transplanted ureter of an intra-abdominally placed third renal transplant resulting in ureteric obstruction associated with small bowel obstruction-a case of double obstruction.

Idiopathic myointimal hyperplasia is a distinct cause of chronic colon ischaemia

AIM

Colon ischaemia (CI) is most commonly an acute and reversible manifestation of a transient, non-occlusive decrease of blood flow in the colonic microvasculature. Irreversible complications are uncommon and the progression to chronic CI remains controversial. Our objective was to identify cases of chronic CI and assess for distinct clinicopathological features.

METHOD

A retrospective review was performed of CI patients having symptom chronicity of ≥ 1 month and ischaemic histology at our institution from 1994 to 2015. Demographic, clinical, endoscopic, radiological, pathological and outcome variables were abstracted. Histological evaluation was performed by two gastrointestinal pathologists.

RESULTS

Fifteen patients (n = 9; 67% men) with a median age of 65 years (range 22-88) were identified. The most common presenting symptoms were diarrhoea and abdominal pain (n = 6, 86%; n = 5, 71%, respectively). The typical endoscopic appearance was segmental ulceration of the sigmoid colon (n = 6, 75%). Vascular imaging showed patent mesenteric vessels in all patients. Histopathological evaluation revealed venous intimal hyperplasia consistent with idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) in eight patients; the remainder showed non-specific ulceration and fibrosis. Surgical resection was performed in seven IMHMV patients, resulting in symptom resolution. On re-review of pre-resection biopsies, all IMHMV patients had characteristic changes of hyperplastic, thick-walled, hyalinized vessels in the lamina propria.

CONCLUSIONS

IMHMV is a unique histopathological entity causing chronic CI. The small vessel histological changes in IMHMV are distinctive in colonic resections and undetectable by routine vascular imaging. Preoperative diagnosis of IMHMV is possible with endoscopic biopsy and segmental colon resection is curative.

Long-Term Endocrine and Exocrine Insufficiency After Pancreatectomy

PURPOSE

To identify peri-operative risk factors and time to onset of pancreatic endocrine/exocrine insufficiency.

METHODS

We retrospectively analyzed a single institutional series of patients who underwent pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) between 2000 and 2015. Endocrine/exocrine insufficiencies were defined as need for new pharmacologic intervention. Cox proportional modeling was used to identify peri-operative variables to determine their impact on post-operative pancreatic insufficiency.

RESULTS

A total of 1717 patient records were analyzed (75.47% PD, 24.53% DP) at median follow-up 17.88 months. Average age was 62.62 years, 51.78% were male, and surgery was for malignancy in 74.35% of patients. Post-operative endocrine insufficiency was present in 20.15% (n = 346). Male gender (p = 0.015), increased body mass index (BMI) (p < 0.001), tobacco use (p = 0.011), family history of diabetes (DM) (p < 0.001), personal history of DM (p ≤ 0.001), and DP (p ≤ 0.001) were correlated with increased risk. Mean time to onset was 20.80 ± 33.60 (IQR: 0.49-28.37) months. Post-operative exocrine insufficiency was present in 36.23% (n = 622). Race (p = 0.014), lower BMI (p < 0.001), family history of DM (p = 0.007), steatorrhea (p < 0.001), elevated pre-operative bilirubin (p = 0.019), and PD (p ≤ 0.001) were correlated with increased risk. Mean time to onset was 14.20 ± 26.90 (IQR: 0.89-12.69) months.

CONCLUSIONS

In this large series of pancreatectomy patients, 20.15% and 36.23% of patients developed post-operative endocrine and exocrine insufficiency at a mean time to onset of 20.80 and 14.20 months, respectively. Patients should be educated regarding post-resection insufficiencies and providers should have heightened awareness long-term.

Breast cancer survivor's perspectives on the role different providers play in follow-up care

IMPORTANCE

Significant variation in the number and types of oncologists that provide breast cancer follow-up exists. However, there is limited understanding regarding breast cancer survivors' preferences for who provides their follow-up. Our objective was to explore breast cancer survivors' perspectives on the goals of breast cancer follow-up, the preferred role for primary care providers, and the perceived roles of different types of oncologists during follow-up.

METHODS

A convenience sample of stage 0-III breast cancer survivors was identified and in-depth one-on-one interviews conducted. Data were analyzed using inductive content analysis.

RESULTS

Survivors cited a strong preference for oncology-based follow-up within the first 5 years after diagnosis, driven by their need for reassurance that cancer had not recurred. Survivors also thought that their primary care provider needed to be involved. Survivors assumed that oncology follow-up was directed by a standard protocol that included streamlining the follow-up team. Survivors recognized that patients with more complex cancers or challenging treatment courses may require more intensive follow-up and deviate from the standard protocol. Most survivors were comfortable deferring decisions regarding who participated in follow-up to the oncology team.

CONCLUSIONS

Most patients think a streamlined approach to oncology-based breast cancer follow-up already occurs, driven by a standard protocol. The use of a standard protocol to provide guidance for which types of oncology providers should participate in breast cancer follow-up will streamline care and represents a significant opportunity to reduce unnecessary variation. This approach is especially critical given patients' strong preferences for oncology-based follow-up.

Capillary Refill Time in Adults Has Poor Inter-Observer Agreement

Objectives

Capillary refill time (CRT) has been taught as a rapid indicator of circulatory status but to be a useful clinical test, CRT needs to be reproducible when performed by another health care worker. No inter-rater agreement studies have been reported for adult patients. The aim of this study was to determine the inter-observer reliability of CRT in a sample of adult emergency department (ED) patients. Methods This prospective observational study included clinically stable ED patients with a variety of conditions from two community EDs. A doctor and a nurse each measured CRT by estimation to the nearest half-second using a standard method on each patient. They were blinded to each other's measurements. The primary outcome of interest was inter-rater agreement. Secondary outcome was agreement in classification as normal or abnormal according to accepted definitions. Data was analysed using bias plot analysis, correlation, absolute percent agreement and kappa analysis. Results Totally, 209 patients were enrolled; 51% were female and 86% were Caucasian. Median CRT was 2 seconds (95% CI 2–2.35 seconds). The mean difference between measurements by the different observers was 0 second, however the 95% limits of agreement were very wide (–1.7 to +1.9 seconds). Agreement was 70% for classification of ‘normal’ or ‘abnormal’ using the 2-second definition of normal, with a kappa of 0.38. Conclusion Interobserver agreement in measurement of CRT was poor in adult subjects with wide limits of agreement. This is a serious threat to the appropriateness of this test for use in clinical practice.

Insulinoma or non-insulinoma pancreatogenous hypoglycemia? A diagnostic dilemma

Insulinoma is the most common cause of endogenous hyperinsulinemic hypoglycemia in adults. An alternate etiology, non-insulinoma pancreatogenous hypoglycemia (NIPH), is rare. Clinically, NIPH is characterized by postprandial hyperinsulinemic hypoglycemia, negative 72-h fasts, negative preoperative localization studies for insulinoma and positive selective arterial calcium infusion tests. Histologically, diffuse islet hyperplasia with increased number and size of islet cells is present and confirms the diagnosis. Differentiating NIPH from occult insulinoma preoperatively is challenging. Partial pancreatectomy is the procedure of choice; however, recurrence of symptoms, although less debilitating, occurs commonly. Medical management with diazoxide, verapamil and octreotide can be used for persistent symptoms. Ultimately, near-total or total pancreatectomy may be necessary. We report a case of a 67-year-old male with hypoglycemia in whom preoperative workup, including computerized tomography abdomen, suggested insulinoma, but whose final diagnosis on pathology was NIPH instead.

Detection of latent tuberculosis infection among migrant farmworkers along the US-Mexico border

Background

Migrant farmworkers are among the highest-risk populations for latent TB infection (LTBI) in the United States with numerous barriers to healthcare access and increased vulnerability to infectious diseases. LTBI is usually diagnosed on the border using the tuberculin skin test (TST). QuantiFERON-TB Gold In-Tube (QFT-GIT) also measures immune response against specific Mycobacterium tuberculosis antigens. The objective of this study is to assess the comparability of TST and QFT-GIT to detect LTBI among migrant farmworkers on the border, as well as to examine the effects of various demographic and clinical factors on test positivity.

Methods

Participants were recruited using mobile clinics on the San Luis US-Mexico border and tested with QFT-GIT and TST. Demographic profiles and clinical histories were collected. Kappa coefficients assessed agreement between TST and QFT-GIT using various assay cutoffs. Logistic regression examined factors associated with positive TST or QFT-GIT results.

Results

Of 109 participants, 59 of 108 (55 %) were either TST (24/71, 34 %) or QFT-GIT (52/106, 50 %) positive. Concordance between TST and QFT-GIT was fair (71 % agreement, ĸ = 0.38, 95 % CI: 0.15, 0.61). Factors associated with LTBI positivity included smoking (OR = 1.26, 95 % CI–1.01–1.58) and diabetes/high blood sugar (OR = 0.70, 95 % CI = 0.51–0.98).

Discussion

Test concordance between the two tests was fair, with numerous discordant results observed. Greater proportion of positives detected using QFT-GIT may help avoid LTBI under-diagnosis. Assessment of LTBI status on the border provides evidence whether QFT-GIT should replace the TST in routine practice, as well as identifies risk factors for LTBI among migrant populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1959-3) contains supplementary material, which is available to authorized users.

Pollination, mating and reproductive fitness in a plant population with bimodal floral-tube length

Mating patterns and natural selection play important roles in determining whether genetic polymorphisms are maintained or lost. Here, we document an atypical population of Lapeirousia anceps (Iridaceae) with a bimodal distribution of floral-tube length and investigate the reproductive mechanisms associated with this pattern of variation. Flowers were visited exclusively by the long-proboscid fly Moegistorhynchus longirostris (Nemestrinidae), which exhibited a unimodal distribution of proboscis length and displayed a preference for long-tubed phenotypes. Despite being visited by a single pollinator species, allozyme markers revealed significant genetic differentiation between open-pollinated progeny of long- and short-tubed phenotypes suggesting mating barriers between them. We obtained direct evidence for mating barriers between the floral-tube phenotypes through observations of pollinator foraging, controlled hand pollinations and measurements of pollen competition and seed set. Intermediate tube-length phenotypes produced fewer seeds in the field than either long- or short-tubed phenotypes. Although floral-tube length bimodality may not be a stable state over long timescales, reproductive barriers to mating and low 'hybrid' fitness have the potential to contribute to the maintenance of this state in the short term.

Search for Spectral Irregularities due to Photon-Axionlike-Particle Oscillations with the Fermi Large Area Telescope

We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the γ-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5×10^{-12}  GeV^{-1} for ALP masses 0.5≲m_{a}≲5  neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the γ-ray opacity of the Universe.

Search for Pompe disease among patients with undetermined myopathies

OBJECTIVE

Pompe disease is a rare treatable glycogen storage disease with in adults - a limb-girdle muscle weakness. Muscle biopsy may fail to show the typical vacuolar myopathy. We asked if we had un-diagnosed patients with Pompe disease in western Sweden.

MATERIAL AND METHODS

We searched the muscle biopsy registry during the time period 1986 until 2006 including 3665 biopsies and included patients at our Neuromuscular Center with unspecified myopathy or limb-girdle muscular dystrophy. The dry blood spot test was used to identify patients with Pompe disease.

RESULTS

A total of 82 patients (46 from the biopsy register and 36 from our center) were seen and dry blood spot test was obtained. No patient with Pompe disease was found. The dry blood spot test was low in three cases (11, 16, and 18% of normal) but a second blood sample showed a normal result based on GAA enzyme activity in lymphocytes in all three patients. In one patient with low normal result of the analysis in lymphocytes a genetic test showed no pathogenic mutations. Further investigation gave a definite diagnose of another myopathy in 12 patients.

CONCLUSIONS

The prevalence of Pompe disease in western Sweden (3 in 1.27 million or 0.24 per 100.000 inhabitants) is lower than in the Netherlands and New York. Re-evaluation of patients with myopathies but without definite diagnosis is rewarding since 12 of 82 patients in our study had a definite molecular diagnosis after workup.