Future imaging modalities for the assessment of pancreas allografts a scan of the horizon.

Pancreas transplantation (PT) allows improved glycaemic control for patients with complicated type 1 diabetes mellitus and is most commonly performed simultaneously with a renal transplant. Imaging modalities are critical for the assessment of pancreatic graft dysfunction, as clinical assessment and hyperglycaemia lack robust sensitivity for the transplant clinician. Biopsy represents the most conclusive standard of PT graft assessment but is challenging due to its invasive nature and the potential morbidity associated with the procedure. Innovative imaging technologies offer the opportunity to apply these modalities to improve PT outcomes while using non-invasive technologies to provide a diagnostic sensitivity that traditionally only biopsies can provide. Early graft dysfunction has traditionally been investigated with Computed tomography (CT) and ultrasound (US) scans. We explore adjuncts to these modalities including the application of contrast enhanced ultrasound (CEUS) for routine post-operative graft assessment to inform post-operative treatment strategies. There is currently a dearth of imaging modalities to reliably monitor long term graft function, but the use of innovative functional imaging techniques and how they can be applied to PT is discussed. Perfusion CT and glucose stimulated magnetic resonance imaging (MRI) to detect whole organ function are examined. In addition, early phase developments in beta-cell specific imaging methods to quantify beta-cell mass longitudinally are described. The clinical applications of such tools including Mn2+-enhanced MR and GLP-1R targeted PET/CT are reviewed and may demonstrate opportunities to provide the transplant clinician with greater information to support improved patient care.

The moment of tooth: rate, fate and pattern of Pacific lingcod dentition revealed by pulse-chase.

Tooth replacement rates of polyphyodont cartilaginous and bony fishes are hard to determine because of a lack of obvious patterning and maintaining specimens long enough to observe replacement. Pulse-chase is a fluorescent technique that differentially colours developing mineralized tissue. We present in situ tooth replacement rate and position data for the oral and pharyngeal detentions of Ophiodon elongatus (Pacific lingcod). We assessed over 10 000 teeth, in 20 fish, and found a daily replacement rate of about two teeth (3.6% of the dentition). The average tooth is in the dental battery for 27 days. The replacement was higher in the lower pharyngeal jaw (LPJ). We found no difference between replacement rates of feeding and non-feeding fish, suggesting feeding was not a driver of tooth replacement. Lingcod teeth have both a size and location fate; smaller teeth at one spot will not grow into larger teeth, even if a large tooth nearby is lost. We also found increased rates of replacement at the posterior of the LPJ relative to the anterior. We propose that lingcod teeth do not migrate in the jaw as they develop; their teeth are fated in size and location, erupting in their functional position.

Systematic review to assess the possibility of return of cerebral and cardiac activity after normothermic regional perfusion for donors after circulatory death.

BACKGROUND: Normothermic regional perfusion (NRP) is a novel technique that aids organ recovery from donors after circulatory death (DCDs). However, ethical concerns exist regarding the potential return of spontaneous cerebral and cardiac activity (ROSCCA). This study aimed to determine the likelihood of ROSCCA in NRP-DCDs of abdominal organs. METHODS: Extracorporeal cardiopulmonary resuscitation (ECPR) for refractory out-of-hospital cardiac arrest (OOHCA) was identified as a comparator for NRP-DCDs and as a validation cohort. A systematic search identified all articles relating to NRP-DCDs and ECPR-OOHCA. Rates of ROSCCA and survival outcomes (ECPR-OOHCA only) were recorded and analysed according to the duration of no perfusion. RESULTS: In NRP-DCDs, 12 of 410 articles identified by database searching were eligible for inclusion. There were no instances of ROSCCA recorded among 493 donors. In ECPR-OOHCA, eight of 947 screened articles were eligible for inclusion (254 patients). Where the absence of perfusion exceeded 5 min in ECPR-OOHCA, there were no survivors with a favourable neurological outcome. CONCLUSION: ROSCCA is unlikely following commencement of NRP and has not occurred to date. Strict observance of the 5-min interval following asystole provides satisfactory assurance that ROSCCA will not occur following NRP.

Indicators of skin barrier integrity among newborns massaged with mustard oil in rural Nepal.

OBJECTIVE: The objective of this study was to determine the skin barrier changes during postnatal month 1 among infants receiving routine mustard oil massage in the humid conditions of rural Nepal. STUDY DESIGN: This was an observational study among 500 live-born neonates receiving mustard oil massage. Skin integrity such as erythema, rash, dryness, skin pH, stratum corneum protein concentration and transepidermal water loss was measured on days 1, 3, 7, 14 and 28. RESULTS: Erythema and rash increased (worsened) during weeks 1 and 2, then decreased over weeks 3 and 4. Skin pH (6.1±0.5 to 5.0±0.6) and stratum corneum protein (16.6±7.9 to 13.5±5.9 µg cm-2) decreased. Transepidermal water loss increased from 33.2±23.5 to 43.0±24.5 g m-2 h-1 at day 28. Skin pH and stratum corneum protein were higher for early versus late premature infants. CONCLUSION: Premature and full-term skin condition was generally poor especially during the first 2 weeks, improving thereafter. Maturational changes were evident.

Renal Allograft Failure After Ipilimumab Therapy for Metastatic Melanoma: A Case Report and Review of the Literature.

Transplant recipients are at an increased risk of malignant melanoma, a result of chronic immunosuppression. Ipilimumab is a newer biological agent targeting T lymphocytes to potentiate an immune response against melanoma, and the use of this agent results in a new adverse effect profile that the clinician must be aware of while a patient is on therapy. We report the case of a male renal transplant recipient who developed graft failure while treated with ipilimumab and minimal immunosuppressive therapy for metastatic ocular melanoma, with biopsy evidence of glomerulonephritis and acute rejection. We highlight the immunological side effects that can manifest from ipilimumab therapy and conclude that it did influence graft function in this patient. Our case illustrates the importance of weighing the risks and benefits to graft function and long-term survival as well as the importance of considering other treatment modalities in this specific group of melanoma patients.

Cross-trimester repeated measures testing for Down's syndrome screening: an assessment.

OBJECTIVES: To provide estimates and confidence intervals for the performance (detection and false-positive rates) of screening for Down's syndrome using repeated measures of biochemical markers from first and second trimester maternal serum samples taken from the same woman. DESIGN: Stored serum on Down's syndrome cases and controls was used to provide independent test data for the assessment of screening performance of published risk algorithms and for the development and testing of new risk assessment algorithms. SETTING: 15 screening centres across the USA, and at the North York General Hospital, Toronto, Canada. PARTICIPANTS: 78 women with pregnancy affected by Down's syndrome and 390 matched unaffected controls, with maternal blood samples obtained at 11-13 and 15-18 weeks' gestation, and women who received integrated prenatal screening at North York General Hospital at two time intervals: between 1 December 1999 and 31 October 2003, and between 1 October 2006 and 23 November 2007. INTERVENTIONS: Repeated measurements (first and second trimester) of maternal serum levels of human chorionic gonadotrophin (hCG), unconjugated estriol (uE3) and pregnancy-associated plasma protein A (PAPP-A) together with alpha-fetoprotein (AFP) in the second trimester. MAIN OUTCOME MEASURES: Detection and false-positive rates for screening with a threshold risk of 1 in 200 at term, and the detection rate achieved for a false-positive rate of 2%. RESULTS: Published distributional models for Down's syndrome were inconsistent with the test data. When these test data were classified using these models, screening performance deteriorated substantially through the addition of repeated measures. This contradicts the very optimistic results obtained from predictive modelling of performance. Simplified distributional assumptions showed some evidence of benefit from the use of repeated measures of PAPP-A but not for repeated measures of uE3 or hCG. Each of the two test data sets was used to create new parameter estimates against which screening test performance was assessed using the other data set. The results were equivocal but there was evidence suggesting improvement in screening performance through the use of repeated measures of PAPP-A when the first trimester sample was collected before 13 weeks' gestation. A Bayesian analysis of the combined data from the two test data sets showed that adding a second trimester repeated measurement of PAPP-A to the base test increased detection rates and reduced false-positive rates. The benefit decreased with increasing gestational age at the time of the first sample. There was no evidence of any benefit from repeated measures of hCG or uE3. CONCLUSIONS: If realised, a reduction of 1% in false-positive rate with no loss in detection rate would give important benefits in terms of health service provision and the large number of invasive tests avoided. The Bayesian analysis, which shows evidence of benefit, is based on strong distributional assumptions and should not be regarded as confirmatory. The evidence of potential benefit suggests the need for a prospective study of repeated measurements of PAPP-A with samples from early in the first trimester. A formal clinical effectiveness and cost-effectiveness analysis should be undertaken. This study has shown that the established modelling methodology for assessing screening performance may be optimistically biased and should be interpreted with caution.

The influence of risk estimates obtained from maternal serum screening on amniocentesis rates.

OBJECTIVE: To investigate the influence of Down syndrome risk estimates obtained from maternal serum screening (MSS) on women's choices regarding amniocentesis. METHODS: Women who screened positive for Down syndrome by an Ontario MSS program between 1993 and 1998 were grouped on the basis of their risk estimate and ethnicity. Amniocentesis uptake rates between the groups were compared in order to determine how the MSS risk estimate influenced uptake. RESULTS: Analysis of 16 792 women showed that amniocentesis uptake rates increased as the estimated risk increased. Uptake in women < or = 35 was higher than that for older women (70% vs 60%, p = 0.001). Uptake in Caucasian and Asian women was higher than the uptake in Black women (67% vs 49%, p = 0.001). Women aged 35 years or older were more likely to proceed with amniocentesis if the MSS risk estimate was higher than their age-specific risk. CONCLUSION: The increase in amniocentesis rate paralleled the increase in MSS risk estimate for Down syndrome. Risk-specific amniocentesis rates are higher in women aged less than 35 years. Women aged 35 years or older whose risk estimate by MSS is lower than their age-specific risk are less likely to opt for amniocentesis.

The effect of fetal gender on the false-positive rate of Down syndrome by maternal serum screening.

OBJECTIVES: (1) To further explore if there is a difference in maternal serum levels of alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG) and estriol (uE3) between fetal genders. (2) To determine if these differences influence false-positive rates of Down syndrome screening in pregnancies with male or female fetuses. METHODS: This is a descriptive study of women screened at the Ontario Maternal Serum Screening program between 1993 and 1995. The women were grouped by fetal gender and ethnicity. Serum levels of the three markers and screening false-positive rates for Down syndrome were compared between fetal genders in women of different ethnicity respectively. RESULTS: Complete data were available for 110 306 pregnancies. In all three ethnic groups, MSAFP levels were significantly decreased and MShCG levels were significantly increased in women with female fetuses. The level of MSuE3 was similar between genders. The difference in false-positive rates of Down syndrome between genders was not statistically significant. CONCLUSIONS: This is the largest study comparing false-positive rates between fetal genders. In contrast to previous studies, the differences in the serum marker levels between fetal genders do not influence the false-positive rates for Down syndrome.

Maternal serum screening in Ontario using the triple marker test.

OBJECTIVES: To summarise the experience and evaluate the performance of the Ontario maternal serum screening (MSS) programme. SETTING: The Ontario MSS programme between October 1993 and September 2000. METHODS: This study used information collected in the Ontario MSS database, which contains data on each screened pregnancy. In the Ontario MSS programme, women are screened between 15 and 20 weeks of gestation. The risk cut-off for Down's syndrome was >or= 1 in 385 at term and women with a serum alpha-fetoprotein >or= 2.2 multiples of the unaffected population median were defined as screen-positive for open neural tube defects. RESULTS: Between 1 October 1993 and 30 September 2000, 428410 women residing in Ontario were screened for open neural tube defects, and 423895 women were screened for Down's syndrome and trisomy 18. Approximately 48% of all pregnant women in the province had MSS. The uptake rate of amniocentesis following a positive Down's syndrome screening was 67%. Of 717 cases of Down's syndrome ascertained in the screened population, 531 were detected by MSS, giving a term detection rate (DR) of 70.6%, with a false-positive rate (FPR) of 7.2%. For neural tube defects, the DR was 72.7%, with a FPR of 2.0%. The screen also detected 50% of cases of trisomy 18 at term, with a FPR of 0.2%. Coincidentally, 113 cases of chromosome aneuploidies other than Down's syndrome and trisomy 18 were detected. DISCUSSION: In the Ontario MSS programme, MSS performed as expected in the detection of Down's syndrome, open neural tube defects and trisomy 18. MSS is an effective and practical method for large-scale second trimester screening for Down's syndrome, open neural tube defects and trisomy 18, and the MSS database is an extremely useful tool in monitoring the performance of this screen.

The influence of applicator angle on dosimetry in vaginal vault brachytherapy.

In vaginal vault brachytherapy, the critical normal tissues are bladder and rectum; doses to these tissues may be affected by the position of a single line applicator placed in the vagina. Dosimetry with the applicator lying at its "natural" angle in the vagina with the patient in the lithotomy position has been compared with the applicator held horizontal as defined by a spirit level in 30 consecutive patients. A mean change in angle of 19.7 degrees was found. This resulted in a mean decrease in ICRU (International Commission of Radiation Units and Measurements) rectal point dose when the applicator is horizontal of 12.9%, equivalent to a mean absolute dose reduction of 1.3 Gy for a prescription dose of 5.5 Gy at 5 mm depth. An increase in mean dose to the ICRU bladder point when the applicator is horizontal of 13.3%, equivalent to an absolute mean dose increase of 0.5 Gy per fraction for the same prescription dose, was also found. On the basis of these findings, it is recommended that vaginal vault brachytherapy is performed with a single line source held in the "corrected" horizontal position to reduce bowel dose as this is the most sensitive critical normal tissue.

Salvage of ischemic digits using a lateral arm fascial flap.

Four patients underwent microvascular transfer of a lateral arm fascial flap to salvage severely ischemic digits by means of induction of neovascularization. The cause of the digital ischemia was direct trauma (crush injury) in one patient and chronic embolic phenomena (proximal arterial occlusion) in three patients. None of the patients had responded to traditional therapy, including treatment with one or more of the following: anticoagulation, lytic therapy, oral vasodilators, digital sympathectomy, and vein bypass grafting. Each patient underwent noninvasive (Doppler ultrasound, digital pressures, digital temperatures, vascular refill) and invasive (angiogram) vascular assessment preoperatively. After microvascular transfer of the lateral arm fascial flap, all patients reported symptomatic relief, and objective improvements were documented by both noninvasive and invasive assessment criteria. One patient developed a seroma at the donor site; another experienced a late complication of thrombosis of the flap after his wound dehisced. A 6-month follow-up evaluation demonstrated neovascular collateralization and stable improvement without regression in the remaining patients. The authors present their clinical experience and propose a treatment algorithm for patients with chronic digital ischemia.

Efficacy of preoperative decontamination of the oral cavity.

This two-part study consisted of: (1) a survey to assess current practice patterns, and (2) an experiment designed to assess the results of varying intraoral preparations. A 48 percent response rate was obtained from the survey of the 318 active members of the American Society of Maxillofacial Surgeons. This survey demonstrated that significant controversy continues regarding the efficacy of preoperative decontamination of the oral cavity. This prospective, randomized experimental study of 30 patients (saline, 10; povidone-iodine, 10; no preparation, 10) demonstrates a significant and sustained reduction of both anaerobic and aerobic bacteria after intraoral preparation with povidone-iodine solution but not saline. The patient's age, use of preoperative intravenous cephalosporin, and type and length of procedure did not influence the postoperative bacterial counts. Although none of the patients in this study developed an infection, recommendations are provided for standardized preoperative treatment of the oral cavity.

Lack of germline CDK6 mutations in familial melanoma.

Germline mutations in genes encoding several components of the retinoblastoma pathway have been linked with inherited predisposition to melanoma. Most commonly, such mutations involve CDKN2A, a cyclin-dependent kinase inhibitor of two kinases, CDK4 and CDK6, which phosphorylate the retinoblastoma protein (pRB) and thereby promote passage through the G1/S cell-cycle restriction point. Less frequently, germline mutations in the CDK4 gene have also been linked with an increased risk of melanoma. Despite the sequence and functional homology between CDK4 and CDK6, the role of germline mutations in CDK6 in melanoma predisposition is unknown. We detected no CDK6 mutations within the p16 (CDKN2A) binding domain in index cases from 60 melanoma-prone kindreds that lacked germline mutations in the coding regions of either CDKN2A or within the entire CDK4 coding region. We conclude that germline mutations in CDK6 do not make a significant contribution to melanoma predisposition.

Association of IL-10 genotype with sudden infant death syndrome.

Sudden infant death syndrome (SIDS) is a major cause of infant death of unknown etiology. We propose that SIDS results from a genetically determined imbalance in the production of inflammatory and anti-inflammatory cytokines in response to the infant's microbial flora. We were especially interested to know the relationship between SIDS and genetically determined higher or lower production of IL-10, an anti-inflammatory cytokine. Biallelic polymorphisms in the promoter region of the IL-10 gene associated with higher or lower production of IL-10 were determined in a SIDS and in a control group using a sequence-specific oligonucleotide approach. One particular allele of the IL-10 gene, the IL-10-592*A allele, was significantly associated with SIDS. Indeed, 70% of the SIDS babies carried the IL-10-592*A allele (p = 0.007 compared with control). In addition, there was a significant reduction in the frequency of homozygosity for the allele IL-10-592*C (p = 0.001 compared with control). Carrying the A allele (either A/A or A/C) had an odds ratio of 3.3 (95% confidence interval 1.4-8.0). In the same patients there was no association with other IL-10 gene polymorphisms nor with other cytokine (TNF-alpha, TGF-beta 1) genotypes, emphasizing the particular relationship between SIDS and the IL-10-592*A allele.

Acquisition of surgical skills: a randomized trial of didactic, videotape, and computer-based training.

BACKGROUND: Although computer-based training (CBT) can enhance didactic instruction, few studies have assessed the efficacy of CBT for basic surgical skills training. This study compares CBT with traditional methods of basic surgical skills training. METHODS: Sixty-nine naive medical students were randomized into 3 treatment groups for basic surgical skills instruction: didactic, videotape, or CBT. All instructional material contained the same pictures, text, and audio. With use of a multiple-choice question examination and a series of performance stations, students were objectively assessed before, immediately after, and 1 month after skills instruction. Raters were blinded to treatment modality during the follow-up evaluation. RESULTS: There were no significant differences among the groups before treatment. After treatment, the didactic group scored higher on the multiple-choice question examination. In contrast, the videotape and CBT groups demonstrated statistically significant (P < .01) enhancement of technical skills compared with the didactic group. After 1 month, a calculated performance quotient revealed statistically significant (P < .01) improvement only in the CBT group. The amount of time students spent practicing their skills was not significantly different among the groups. CONCLUSIONS: CBT is as effective as, and possibly more efficient, than traditional methods of basic surgical skills training for medical students.

Surgical treatment of tracheomediastinal fistula from recurrent Hodgkin's lymphoma.

The role of surgery in the management of Hodgkin's disease is usually diagnostic because chemotherapy and radiation are often curative. We report here the surgical treatment of a tracheomediastinal fistula from recurrent Hodgkin's lymphoma.

Mutation of the CDKN2A 5' UTR creates an aberrant initiation codon and predisposes to melanoma.

Approximately 8-12% of melanoma is inherited in an autosomal dominant fashion with variable penetrance. A chromosome 9p21 locus has been linked to this disease in 50-80% of affected families. CDKN2A (also known as P16, INK4, p16INK4A and MTS1) is allelic to this locus and encodes a cdk4/cdk6 kinase inhibitor that constrains cells from progressing through the G1 restriction point. Although germline CDKN2A coding mutations cosegregate with melanoma in 25-60% of families predisposed to the disease, there remains a number of mutation-negative families that demonstrate linkage of inherited melanoma to 9p21 markers. We show here that a subset of these kindreds possess a G-->T transversion at base -34 of CDKN2A, designated G-34T. This mutation gives rise to a novel AUG translation initiation codon that decreases translation from the wild-type AUG. The G-34T mutation is not seen in controls, segregates with melanoma in families and, on the basis of haplotyping studies, probably arose from a common founder in the United Kingdom. Characterization of this and other CDKN2A non-coding mutations should have an impact on current efforts to identify susceptible melanoma-prone families and individuals.

The core metal-recognition domain of MerR.

MerR, the metalloregulatory protein of the mercury-resistance operon (mer) has unusually high affinity and specificity for ionic mercury, Hg(II). Prior genetic and biochemical evidence suggested that the protein has a structure consisting of an N-terminal DNA binding domain, a C-terminal Hg(II)-binding domain, and an intervening region involved with communication between these two domains. We have characterized a series of MerR deletion mutants and found that as little as 30% of the protein (residues 80-128) forms a stable dimer and retains high affinity for Hg(II). Biophysical measures indicate that this minimal Hg(II)-binding domain assumes the structural characteristics of the wild-type full-length protein both in the Hg(II) center itself and in an immediately adjacent helical protein domain. Our observations are consistent with the core Hg(II)-binding domain of the MerR dimer being constituted by a pair of antiparallel helices (possibly in a coiled-coil conformation) comprised of residues cysteine 82 through cysteine 117 from each monomer followed by a flexible loop through residue cysteine 126. These antiparallel helices would have a potential Hg(II)-binding site at each end. However, just as in the full-length protein, only one of these potential binding sites in the deleted proteins actually binds Hg(II).

Psychological outcomes following maternal serum screening: a cohort study.

BACKGROUND: Maternal serum screening is used to assist in the prenatal detection of congenital anomalies. Its use is controversial, and one concern that has been expressed is its psychological effects on women. The authors examined whether this test leads to an increase in anxiety and depression among women who have a false-positive result as compared with those who have a true-negative result or do not undergo testing. METHODS: A prospective cohort study with baseline assessment at 15 to 18 weeks' gestation and follow-up at 24 weeks' gestation was conducted. Pregnant women at 8 geographically diverse sites across Ontario were recruited. The main outcome measures were the state portion of the State--Trait Anxiety Inventory and the Center for Epidemiologic Studies Depression Scale. RESULTS: Of the 2418 potential subjects 2020 (83.5%) were enrolled and eligible; 1741 (86.2%) completed the follow-up. A total of 1177 women (67.6%) underwent maternal serum screening. No overall adverse psychological effects as a result of testing were found at 24 weeks' gestation. Women with a false-positive result had a mean increase in anxiety score of 1.6 (95% confidence interval [CI] -1.7 to 4.9), whereas women with a true-negative result had a mean decrease of 1.1 (95% CI -1.8 to -0.3) and those not tested had a mean decrease of 0.4 (95% CI -1.3 to 0.5). The mean depression score increased by 0.5 (95% CI -0.9 to 2.0) in the false-positive group, was unchanged (95% CI -0.3 to 0.4) in the true-negative group and increased by 0.2 (95% CI -1.7 to 1.2) in the not tested group. Of the women who underwent testing, 87 (7.6%) were unsure of their result at the time of follow-up. INTERPRETATION: The results suggest that maternal screening in Ontario is not causing serious psychological harm to women. Communication regarding test results could be improved, since a substantial proportion of women were unsure of their test result.