Megaplasmid Dissemination in Multidrug-Resistant Salmonella Serotypes from Backyard and Commercial Broiler Production Systems in the Southeastern United States

Over the past decade, there has been a rise in U.S. backyard poultry ownership, raising concern for residential area antimicrobial-resistant (AMR) Salmonella contamination. This study aims to lay the groundwork to better understand the persistence of AMR Salmonella in residential broiler production systems and make comparisons with commercial systems. Ten backyard and 10 commercial farms were sampled at three time points across bird production. Both fecal (n = 10) and environmental (soil, n = 5, litter/compost, n = 5, feeder, and waterer swabs, n = 6) samples were collected at each visit on days 10, 31, and 52 of production for backyard farms and days 10, 24, and 38 of production for commercial farms. AMR Salmonella was characterized phenotypically by broth microdilution and genotypically by whole-genome sequencing. Overall, Salmonella was more prevalent in commercial farm samples (52.31%) over backyard farms (19.10%). Kentucky (sequence type (ST) 152) was the most common serotype found in both backyard and commercial farms. Multidrug-resistant (MDR, resistance to ≥3 or more antimicrobial classes) isolates were found in both production systems, while ciprofloxacin- and nalidixic acid-resistant and intermediate isolates were more prevalent in commercial (33%) than backyard samples (1%). Plasmids that have been associated with MDR were found in Kentucky and Infantis isolates, particularly IncFIB(K)_1_Kpn3 megaplasmid (Infantis). Our study emphasizes the need to understand the selection pressures in disseminating megaplasmids in MDR Salmonella in distinct broiler production systems.

Tracking the Transmission of Antimicrobial-Resistant Non-O157 Escherichia coli and Salmonella Isolates at the Interface of Food Animals and Fresh Produce from Agriculture Operations Using Whole-Genome Sequencing

An increasing number of outbreaks are caused by foodborne pathogens such as Escherichia coli and Salmonella, which often harbor antimicrobial resistance (AMR) genes. We previously demonstrated the transmission of pathogens from animal operations to produce fields on sustainable farms, which illustrated an urgent need to develop and implement novel prevention methods and remediation practices such as the vegetative buffer zone (VBZ) to prevent this movement. The focus of this study was to use whole-genome sequencing (WGS) to characterize the AMR, virulence, and single-nucleotide polymorphism profile of 15 Salmonella and 128 E. coli isolates collected from small-scale dairy and poultry farms on a research station in North Carolina. Phenotypically, seven E. coli and three Salmonella isolates displayed resistance to antibiotics such as tetracycline (n = 4), ampicillin (n = 4), nalidixic acid (n = 3), chloramphenicol (n = 2), sulfisoxazole (n = 1), and streptomycin (n = 1). A single E. coli isolate was found to be resistant to five different antibiotic class types and possessed the bla_TEM-150 resistance gene. Virulence genes that facilitate toxin production and cell invasion were identified. Mauve analysis of the E. coli isolates identified seven clusters (dairy-six and poultry-one) indicating that transmission is occurring from animal operations to fresh produce fields and the surrounding environment when the VBZ is denudated. This suggests that the VBZ is a useful barrier to reducing the transmission of enteric pathogens in agricultural systems. Our study demonstrates the prevalence of AMR and virulence genes on small-scale sustainable farms and highlights the advantage of using WGS to assess the impact of the VBZ to reduce the transmission of E. coli and Salmonella.

Antimicrobial resistance and virulence factors profile of Salmonella spp. and Escherichia coli isolated from different environments exposed to anthropogenic activity

OBJECTIVE

The study aimed to identify the antimicrobial resistance (AMR) determinants and virulence factors in Salmonella spp. and Escherichia coli recovered from different anthropogenic areas in North Carolina.

METHODS

Soil samples were collected from different anthropogenic areas, urban and natural. The minimum inhibitory concentration (MIC) was determined by using the broth microdilution method. Whole-genome sequencing (WGS) and analysis were done to identify the AMR determinants and virulence factors.

RESULTS

A higher prevalence of Salmonella spp. and E. coli was detected in the urban environment. The Salmonella spp. isolates showed resistance to sulfisoxazole and streptomycin, whereas E. coli was resistant to sulfisoxazole, cefoxitin and ampicillin. Salmonella serotypes Schwarzengrund and Mississippi were identified based on WGS analysis. Aminoglycoside resistance genes and IncFIB and IncFIC(FII) plasmids were detected among Salmonella spp. In general, E. coli was predominated by isolates from phylogroups B1, B2 and D. The multidrug transporter mdfA gene was detected in most of the E. coli from both the urban (100%) and natural (84.5%) environments. The FosA7 gene was detected in an isolate from a residential yard. The pCoo and pB171 plasmids were detected in an urban environment; col(156) and pHN7A8 plasmids were detected in natural environments.

CONCLUSIONS

The detection of AMR determinants and virulence factors in these bacteria is significant in understanding the occurrence and even the development of AMR. The presence of these determinants in different anthropogenic areas suggests the need to conduct longitudinal studies for comparing the profile of pathogens across different environments.

Extended-spectrum ß-lactamase-producing Escherichia coli among humans, chickens and poultry environments in Abuja, Nigeria

BACKGROUND

Globally, chicken is known to be a reservoir for the spread of antimicrobial resistance genes to humans. In Nigeria, antimicrobial drugs are readily accessible for use in poultry production, either for preventive or therapeutic purposes. Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) are transmissible to humans because of their zoonotic potentials. People working very closely with chickens either on farms or markets are at greater risk. The aim of this study was to investigate the prevalence and zoonotic transmission of ESBL-EC among poultry-workers, chickens, and poultry environments in Abuja, Nigeria.

METHODS

We conducted a cross-sectional study among workers, chickens and poultry environment in selected farms/chicken markets in Abuja. Stool, faecal, and environmental samples were collected from apparently healthy workers, chickens, and farm/market environments from December 2018 to April 2019. Data were collected electronically using an open data kit (ODK) installed on a Smartphone. Antimicrobial resistance was determined using broth micro-dilution methods against a panel of 14 antimicrobial agents. We carried out the phenotypic and genotypic characterization of the isolates. Data were analyzed by computing frequencies, proportions and spearman's correlation (ρ).

RESULTS

Of 429 samples, 26.8% (n = 115) were positive for Escherichia coli (E. coli). Of the 115 E. coli isolates, 32.2% (n = 37) were confirmed ESBL producers by phenotypic characterization. Prevalence of ESBL-EC was highest among both poultry-workers (37.8%; n = 14) and chickens (37.8%; n = 14) followed by the environment (24.3%; n = 9). Both human and chicken isolates showed similar patterns of multidrug resistance to tested antimicrobials with a positive correlation (ρ = 0.91). Among ESBL producers, we observed the dissemination of blaCTX-M (10.8%; n = 4) genes. The coexistence of blaCTX-M-15 and blaTEM-1 genes was observed in 8.1% (n = 3) of the isolates, out of which (66.7%; n = 2) were chicken isolates from the farm, while a single human isolate was from the chicken market.

CONCLUSIONS

ESBL-EC isolates were prevalent amongst apparently healthy individuals, chickens and the poultry farm/market environment in Abuja. It is important to educate healthcare workers that people in proximity with poultry are a high-risk group for faecal carriage of ESBL-EC, hence pose a higher risk to the general population for the spread of antimicrobial resistance.

Thermoacoustic contrast of prostate cancer due to heating by very high frequency irradiation

Applying the thermoacoustic (TA) effect to diagnostic imaging was first proposed in the 1980s. The object under test is irradiated by high-power pulses of electromagnetic energy, which heat tissue and cause thermal expansion. Outgoing TA pressure pulses are detected by ultrasound transducers and reconstructed to provide images of the object. The TA contrast mechanism is strongly dependent upon the frequency of the irradiating electromagnetic pulse. When very high frequency (VHF) electromagnetic irradiation is utilized, TA signal production is driven by ionic content. Prostatic fluids contain high levels of ionic metabolites, including citrate, zinc, calcium, and magnesium. Healthy prostate glands produce more ionic metabolites than diseased glands. VHF pulses are therefore expected to generate stronger TA signal in healthy prostate glands than in diseased glands. A benchtop system for performing ex vivo TA computed tomography with VHF energy is described and images are presented. The system utilizes irradiation pulses of 700 ns duration exceeding 20 kW power. Reconstructions frequently visualize anatomic landmarks such as the urethra and verumontanum. TA reconstructions from three freshly excised human prostate glands with little, moderate, and severe cancerous involvement are compared with histology. TA signal strength is negatively correlated with percent cancerous involvement in this small sample size. For the 45 regions of interest analyzed, a reconstruction value of 0.4 mV provides 100% sensitivity but only 29% specificity. This sample size is far too small to draw sweeping conclusions, but the results warrant a larger volume study including comparison of TA images to the gold standard, histology.

Abdominal subcutaneous adipose tissue insulin resistance and lipolysis in patients with non-alcoholic steatohepatitis

BACKGROUND

Systemic insulin resistance (IR) is a primary feature in non-alcoholic steatohepatitis (NASH), however, there remain limited data on tissue-specific insulin sensitivity in vivo.

METHODS

We examined tissue-specific (adipose, muscle and liver) insulin sensitivity and inflammation in 16 European Caucasian patients with biopsy-confirmed NASH and in 15 healthy controls. All underwent a two-step hyperinsulinaemic euglycaemic clamp incorporating stable isotope measurements of carbohydrate and lipid metabolism with concomitant subcutaneous adipose tissue (SAT) microdialysis.

RESULTS

Hepatic and muscle insulin sensitivity were decreased in patients with NASH compared with controls, as demonstrated by reduced suppression of hepatic glucose production and glucose disposal (Gd) rates following insulin infusion. In addition, rates of lipolysis were higher in NASH patients with impaired insulin-mediated suppression of free fatty acid levels. At a tissue specific level, abdominal SAT in patients with NASH was severely insulin resistant, requiring >sixfold more insulin to cause ½-maximal suppression of glycerol release when compared with healthy controls. Furthermore, patients with NASH had significantly higher circulating levels of pro-inflammatory adipocytokines than controls.

CONCLUSION

NASH patients have profound IR in the liver, muscle and in particular adipose tissues. This study represents the first in vivo description of dysfunctional SAT in patients with NASH.

Effectiveness of 0.05% oxymetazoline (Vicks Sinex Micromist®) nasal spray in the treatment of objective nasal congestion demonstrated to 12 h post-administration by magnetic resonance imaging

INTRODUCTION

This study aimed to assess the qualitative and quantitative utility of MRI imaging to illustrate the magnitude and duration of the effect of a standard 100 μg dose of oxymetazoline in a commercially available formulation that also contains aromatic oils.

METHODS

This was a randomized, open label, single dose, parallel group study in 21 adult male and female subjects who reported moderate to severe nasal congestion due to acute upper respiratory tract infection or hay fever. MRI scans were acquired using a 3T Philips Achieva scanner with a 16 channel head receive coil. High resolution MRI scans of the nasal turbinates were obtained immediately prior to dosing (baseline) and at approximately 1, 8, 10, 11, and 12 h after dosing. The efficacy variables of primary interest were inferior turbinate total volume at 8 and 12 h post-dosing. The secondary efficacy variables analysed were inferior turbinate total volume at 1, 10, and 11 h post-dosing, middle turbinate total volume at 1, 8, 10, 11, and 12 h post-dosing.

RESULTS

Changes from baseline volumes measured for the inferior and middle turbinates of subjects receiving the oxymetazoline formulation showed significant (P < 0.05) decreases at all times up to and including 12 h post-administration. No significant decreases from baseline were detected in subjects receiving a sham 'spray' (untreated control - spray bottles with no spray solution). Statistical ANCOVA results of inferior and middle turbinate volume indicated significant differences (P < 0.05) at all measurement points up to and including 12 h post-administration between the oxymetazoline treatment group and the untreated control with the only exception the middle turbinate volume at 10 h (P = 0.0896). The significant changes were likely to be clinically relevant though this was not measured in the study. No AEs were reported during this study and no other safety evaluations were made.

CONCLUSIONS

This study showed that MRI assessment of nasal congestion in human volunteers is a robust, repeatable and viable measurement technique. The application of a 100 μg Vicks Sinex Micromist(®) nasal decongestant (0.05% oxymetazoline solution) delivered a highly significant reduction in inferior and middle turbinate volumes compared with the application of a control, measurable by the MRI method up to and including a 12 h post-dose scan.

Sorafenib for advanced hepatocellular carcinoma (HCC): impact of rationing in the United Kingdom

BACKGROUND

The prognosis for hepatocellular carcinoma (HCC) is dependent upon tumour stage, performance status (PS), severity of underlying liver disease, and the availability of appropriate therapies. The unavailability of sorafenib may have a significantly adverse effect on the prognosis of UK patients with advanced HCC. During the study period, access to sorafenib was at the discretion of local health funding bodies, a process that may delay or deny access to the drug and that remains in place for Wales, Scotland, and Northern Ireland. Here, we attempt to address the impact of this system on patients with advanced HCC in the United Kingdom.

METHODS

This is a retrospective study performed in the two largest specialist hepatobiliary oncology units in the United Kingdom. Funding applications were made to local funding bodies for patients with advanced HCC for whom sorafenib was considered appropriate (advanced HCC not suitable for loco-regional therapies, compensated chronic liver disease, PS 0-2).

RESULTS

A total of 133 applications were made, of which 57 (43%) were approved and 76 (57%) declined. Demographics and prognostic factors were balanced between the two groups. This cohort had a number of adverse prognostic features: patients were predominantly PS 1-2; the majority had multifocal disease with the largest lesion being >5 cm; and macroscopic vascular invasion, metastases, and AFP >,000 ng ml(-1), were each present in one-third of cases. The median time from application to funding decision was 17 days (range 3-260 days). For the primary 'intention-to-treat' analysis, median overall survival was 4.1 months when funding was declined, and 9.5 months when funding was approved (hazard ratio (HR) 0.48; 95% CI 0.3186-0.7267; P=0.0005).

CONCLUSION

These data support the use of sorafenib for patients with advanced HCC as an effective intervention. In the United Kingdom, this applies to a relatively small group of patients, estimated to total ∼800 per year who, unfortunately, do not survive long enough to themselves lobby for the availability of this drug. These data provide a comparison of sorafenib with supportive care and demonstrate the potential detrimental impact on patient outcomes of rationing health-care resources on the basis of cost.

Post-axial polydactyly type A2, overgrowth and autistic traits associated with a chromosome 13q31.3 microduplication encompassing miR-17-92 and GPC5

Genomic rearrangements at chromosome 13q31.3q32.1 have been associated with digital anomalies, dysmorphic features, and variable degree of mental disability. Microdeletions leading to haploinsufficiency of miR17∼92, a cluster of micro RNA genes closely linked to GPC5 in both mouse and human genomes, has recently been associated with digital anomalies in the Feingold like syndrome. Here, we report on a boy with familial dominant post-axial polydactyly (PAP) type A, overgrowth, significant facial dysmorphisms and autistic traits who carries the smallest germline microduplication known so far in that region. The microduplication encompasses the whole miR17∼92 cluster and the first 5 exons of GPC5. This report supports the newly recognized role of miR17∼92 gene dosage in digital developmental anomalies, and suggests a possible role of GPC5 in growth regulation and in cognitive development.

Oral Candida infection and colonization in solid organ transplant recipients

INTRODUCTION

Oral Candida carriage and infection have been reported to be associated with a greater risk for systemic infection in transplant recipients; however, a systematic analysis of the oral Candida titers and species has not been previously conducted. The objectives of this study were to determine the prevalence of oropharyngeal candidiasis, the oral carrier status, Candida titers and species in this population.

METHODS

Ninety kidney and heart transplant subjects and 72 age-matched healthy controls were included. Swabs from the oral mucosa and a standardized amount of unstimulated saliva were plated on Chromagar Candida, and colony-forming units per millilitre were calculated. Initial speciation was based on colony color and was confirmed by standard germ tube, biotyping, or polymerase chain reaction assays.

RESULTS

Infection with C. albicans was detected in seven transplant subjects and none of the controls. The transplant group had significantly higher oral Candida titers than the control group. There were no statistically significant relationships between the dose or type of immunosuppressants and oral Candida titers or infection. A significantly higher percentage of transplant subjects were colonized by more than one species, compared with control subjects. The most frequent species combination in transplant subjects was C. albicans and C. glabrata. C. glabrata was isolated from 13.5% of transplant carriers and none of the controls.

CONCLUSIONS

Increased oral Candida infection and carriage titers were found in the transplant population. Although the majority of transplant patients were colonized by C. albicans, C. glabrata appears to emerge as the second most prevalent species.

The (my)Grid ontology: bioinformatics service discovery

(my)Grid supports in silico experiments in the life sciences, enabling the design and enactment of workflows as well as providing components to assist service discovery, data and metadata management. The (my)Grid ontology is one component in a larger semantic discovery framework for the identification of the highly distributed and heterogeneous bioinformatics services in the public domain. From an initial model of formal OWL-DL semantics throughout, we now adopt a spectrum of expressivity and reasoning for different tasks in service annotation and discovery. Here, we discuss the development and use of the (my)Grid ontology and our experiences in semantic service discovery.

Effects of creating a non-specific, virus-hostile environment in the nasopharynx on symptoms and duration of common cold

The Common Cold remains the most frequent symptomatic viral infection in man. Current best therapies are all symptomatic. New pharmacological therapies are likely to be prescription-bound, and as most Common Cold infections are successfully treated without the intervention of a Physician, there is a need for effective non-prescription therapy options. Aim of this study is to propose a new type of approach, based on the concept of making a hostile biological environment for virus survival and spreading at the point of infection, the nasopharynx. The hypothesis was advanced that infections could be controlled using a physical biological approach to create an environment at the point of infection, that is inhibitory to the survival, and persistence of infecting virus, and of viruses newly released from infected mucosal epithelial cells. A nasal irrigation spray, designed to deliver a low pH gel to the nasal cavity, was developed and tested in this study. The study was a randomised, parallel, double-blind, placebo-controlled evaluation of three formulations of irrigation nasal spray in 441 subjects. The objective was to test whether the formulations reduced Cold severity and Cold duration compared to a placebo nasal spray. Subjects were recruited, and supplied with the product when healthy, and were instructed to begin treating and recording symptom severity once they experienced the "first signs" of a Common Cold. To qualify, subjects had to volunteer that they had at least one of the symptoms: sore/scratchy throat, runny nose or congested nose. The product was used 4 times daily, with at least 4 hours separating each dose, for a maximum of 7 days. Efficacy was assessed by an Interactive Voice Recall System whereby subjects were required to contact the investigation site, by telephone, twice daily when they were asked to assess the severity of their symptoms using a four point ordinal scale where 0 = "absent", and 3 = "severe". The symptoms assessed were sore throat, runny nose, blocked nose, cough and tired/run-down feeling. Two formulations demonstrated significant effects. A hydroxy methyl propyl cellulose based formulation reduced symptom severity compared with placebo by 17% and a Poloxamer based formulation reduced severity by 21%. Duration of illness was reduced with a hydroxy methyl propyl cellulose based formulation by 1.5 days to 2.4 days (according to the dose) and by a Poloxamer based formulation by 2.5 days. Results of this study suggest that the creation of a non virus-specific, inhibitory environment in the nasopharynx holds promise as an effective method of controlling the severity and duration of the Common Cold.

ATP-binding cassette transporters are required for efficient RNA interference in Caenorhabditis elegans

RNA interference (RNAi) is a conserved gene-silencing phenomenon that can be triggered by delivery of double-stranded RNA (dsRNA) to cells and is a widely exploited technology in analyses of gene function. Although a number of proteins that facilitate RNAi have been identified, current descriptions of RNAi and interrelated mechanisms are far from complete. Here, we report that the Caenorhabditis elegans gene haf-6 is required for efficient RNAi. HAF-6 is a member of the ATP-binding cassette (ABC) transporter gene superfamily. ABC transporters use ATP to translocate small molecule substrates across the membranes in which they reside, often against a steep concentration gradient. Collectively, ABC transporters are involved in a variety of activities, including protective or barrier mechanisms that export drugs or toxins from cells, organellar biogenesis, and mechanisms that protect against viral infection. HAF-6 is expressed predominantly in the intestine and germline and is localized to intracellular reticular organelles. We further demonstrate that eight additional ABC genes from diverse subfamilies are each required for efficient RNAi in C. elegans. Thus, the ability to mount a robust RNAi response to dsRNA depends upon the deployment of two ancient systems that respond to environmental assaults: RNAi mechanisms and membrane transport systems that use ABC proteins.

Methods for delivery of double-stranded RNA into Caenorhabditis elegans

The nematode Caenorhabditis elegans is often employed in investigations of diverse aspects of biology, including behavior, development, basic cellular processes, and disease states. The ability to utilize double-stranded RNA (dsRNA) to inhibit specific gene function in this organism has dramatically increased its value for these kinds of studies and has provided more flexibility in experimental design that include procedures. Here, we have collected a set of protocols from the C. elegans community for propagation of C. elegans, techniques for dsRNA preparation, four basic methods for delivery of dsRNA to C. elegans (injection, soaking, feeding, and in vivo delivery), and we suggest schemes that should facilitate detection of specific gene silencing.

Beneficial pharmacokinetic interaction between cyclosporine and itraconazole in renal transplant recipients

BACKGROUND

Itraconazole is often given for fungal prophylaxis to renal transplant recipients, who require concomitant cyclosporine in the immediate posttransplant period. We determined the extent of the pharmacokinetic interaction between cyclosporine and itraconazole oral solution in renal transplant recipients and the effect on daily drug costs.

METHOD

This was a single-center, open-label, nonrandomized study. Posttransplantation, renal transplant recipients received itraconazole solution 200 mg twice daily and cyclosporine, dosed to achieve target concentrations. Once at steady state, blood samples were collected over 12 hours for pharmacokinetic evaluation of cyclosporine, itraconazole, and hydroxy-itraconazole. Itraconazole was discontinued after approximately a 3-month prophylaxis regimen. Cyclosporine doses were titrated to achieve target concentrations and cyclosporine concentrations were once again determined when steady state was achieved. A noncompartmental analysis was used to analyze cyclosporine pharmacokinetic parameters. The pharmacoeconomic impact was measured based on the percent change in dose of cyclosporine when administered with and without itraconazole. Drug costs were calculated using the average wholesale price. The cost per patient, as well as the average cost, was calculated for the cyclosporine/itraconazole combination, as well as the cyclosporine regimen alone.

RESULTS

Eight renal transplant recipients completed the study. All were included for itraconazole analyses and seven for cyclosporine analyses. Mean peak and trough itraconazole levels were 1.64 +/- 0.82 and 1.23 +/- 0.90 microg/mL respectively. Mean peak and trough hydroxy-itraconazole levels were 2.37 +/- 1.55 and 2.20 +/- 1.48 microg/mL, respectively. While on itraconazole, a 48% reduction in the mean total daily dose of cyclosporine was necessary to maintain target concentrations (171 +/- 63.6 versus 329 +/- 103.5 mg, P =.003). This reduction in cyclosporine dose resulted in a discounted itraconazole daily drug cost of approximately 29.5%.

CONCLUSION

Administering itraconazole with cyclosporine allows for a decrease in the cyclosporine dose, thus lowering daily drug costs and providing adequate antifungal coverage with itraconazole and hydroxy-itraconazole trough concentrations above the MIC(90) of Candida and Aspergillus spp.

Hand assisted laparoscopic donor nephrectomy: a comparison with the open approach

PURPOSE

Hand assisted laparoscopy combines aspects of open and laparoscopic surgery. A hand in the abdomen may facilitate laparoscopic live donor nephrectomy, allowing more urologists to participate. We report and compare our initial series of hand assisted laparoscopy donor nephrectomy with nephrectomy performed by standard open methods.

MATERIALS AND METHODS

In the last 18 months 60 patients at 2 institutions underwent hand assisted laparoscopy donor nephrectomy. This cohort was compared to a contemporary group of 31 patients who underwent open donor nephrectomy via a flank incision at our 2 institutions. Demographic and outcome data were compared retrospectively in a nonrandomized fashion in the 2 groups.

RESULTS

Demographic data on patient age, male-to-female ratio and body mass index were similar in the 2 groups. Operative time, transfusion rate, time to oral intake and complications were also similar. However, estimated blood loss, change in hematocrit preoperatively to postoperatively, hospitalization, parenteral and oral narcotic requirement, and donor convalescence were significantly less in the hand assisted laparoscopy versus open groups. In terms of allograft function, nadir creatinine, time to nadir creatinine, creatinine clearance at 6, 12, and 18 months, delayed graft function, episodes of acute rejection and ureteral stricture were similar in the groups.

CONCLUSIONS

Hand assisted laparoscopy is safe, efficacious and reproducible for living related donor nephrectomy. Compared with the open technique hand assisted laparoscopy provides the donor with significantly decreased postoperative morbidity, while enabling excellent allograft function. Further randomized prospective studies are warranted.

Use of cryopreserved cadaveric vein allograft for hemodialysis access precludes kidney transplantation because of allosensitization

BACKGROUND

Dimethyl sulfoxide-cryopreserved cadaveric vein allografts have recently been proposed as an alternative to prosthetic grafts in the problem hemodialysis population. The transfer of mismatched major histocompatibility complex I and II molecules in association with these allografts can potentially lead to allosensitization in nonimmunosuppressed individuals.

METHODS

In a university-affiliated medical center, 20 consecutive patients receiving technically successful upper arm cadaveric vein allograft fistulas (CAVFs) for hemodialysis between April 1999 and April 2000 were studied. A control cohort of 20 patients on a kidney transplantation waiting list was selected by nurses blinded to the study. These patients were matched for age, sex, history of transfusion, pregnancy, cause of kidney failure, and prior transplantation. The panel reactive antibody (PRA) values were recorded in this group over the same time period as the CAVF group.

RESULTS

Patients receiving CAVFs had a mean PRA assay value of 84.1% (median, 96.5%) at an average of 3.1 months after engraftment (median, 1.5 months). The preengraftment PRA values were available for seven patients who were on the transplant waiting list. Six of these patients had nonreactive PRA assays before CAVF creation. All of these patients converted to positive PRA assays after CAVF creation with a mean value of 92.3% (median, 98%) at 2.85 months follow-up (median, 1.3 months). The mean PRA value for the control cohort was 5.5% (median, 2.5%), with no patients converting from a nonreactive to a reactive PRA assay during this same time interval.

CONCLUSION

The use of dimethyl sulfoxide-cryopreserved cadaveric vein allografts for hemodialysis access leads to broad allosensitization as measured by PRA assay. Cryopreserved cadaveric vein allografts should not be used for hemodialysis access in potential kidney transplant recipients.

Fatty acid balance studies in preterm infants fed formula milk containing long-chain polyunsaturated fatty acids (LCP) II

A milk formula (Prematil-LCP) containing long-chain polyunsaturated fatty acids (LCP) and with a fatty acid profile closely resembling breast milk has recently been introduced for preterm infants. A double-blind randomized controlled trial was performed comparing fatty acid absorption from Prematil-LCP (n=10) and standard Prematil (n=10). Formula-fed preterm infants underwent 3 d fat balances (once full enteral feeds were established) along with a parallel human milk fed group (n=11). Plasma samples were taken on the last day. Median total fat excretion (absorption, %) was 2.34g kg(-1) (82.0), 2.64g kg(-1) (82.9) and 1.65g kg(-1) (87.8) with Prematil, Prematil-LCP and human milk feeding, respectively. This reflected differences in the excretion and absorption of long-chain saturated fatty acids. All groups excreted detectable LCP. LCP disappearance was higher in infants fed human milk than in those fed Prematil-LCP, particularly for n-6 LCP (p < 0.01). Nevertheless, excreted LCP equated to < 30% dietary intake, with Prematil-LCP feeding. Plasma lipid fatty acid composition reflected differences in dietary LCP intake.

Fatty acid balance studies in term infants fed formula milk containing long-chain polyunsaturated fatty acids

Long-chain polyunsaturated fatty acids (LCP) are thought to be required for optimal nervous system development in the newborn. A commercial milk formula containing LCP (Aptamil-LCP) with a fatty acid profile closely resembling breast milk, has recently been introduced for term infants. The absorption of fatty acids in term infants was examined in a double-blind randomized controlled trial comparing Aptamil-LCP (n = 20) and standard Aptamil (n = 20). Formula-fed newborn infants were studied from birth for 14 d. Fat balances (3 d) were performed from d 10. A 3-d stool collection was performed from d 10 in a parallel breastfed group (n = 21). Plasma samples were taken on d 6. Median fat excretion (mg kg[-1]) was 897.1, 615.0 and 355.2 with Aptamil, Aptamil-LCP and breastfeeding, respectively. The median total fat absorption coefficient in Aptamil-LCP-fed infants was higher than in those fed standard Aptamil (p < 0.01). These findings were accounted for by differences in the excretion and absorption of long-chain saturated fatty acids (C14:0, C16:0 and C18:0). Higher fat excretion was associated with bulkier and firmer stools. Only trace amounts of LCP were detected in the stools of all groups. This accounted for less than 4% of dietary intake in Aptamil-LCP-fed infants. No differences in the utilization of LCP from Aptamil-LCP and breast milk feeding were apparent. Plasma phospholipid fatty acid composition data reflected differences in dietary LCP intake. Thus, PL LCP levels were highest in the breastfed infants and lowest in the Aptamil-fed infants, with values for the Aptamil-LCP-fed group falling in between.

Superior mesenteric vein occlusion presenting with a massive vascular malformation of the colon

Superior mesenteric vein occlusion is a rare condition which has protean clinical manifestations. It frequently occurs secondary to an underlying coagulation defect. We present the case of a young female who presented uniquely with a massive colonic vascular malformation and who had various predisposing factors, the most serious being a protein C deficiency.

Metabolic rate of sleeping infants

AIM

To measure the sleeping metabolic rate (SMR) of healthy infants in the first year of life.

METHODS

The SMR was measured on 73 infants aged 1 to 12 months in a special nursery using indirect calorimetry. One hundred satisfactory observations were made. The room air and radiative temperatures, humidity, and amount of insulation were measured. Parents chose the clothing and bedding that they judged their infant needed.

RESULTS

The mean (SD) SMR was 2.4 (0.4) watts (W)/kg or 45 (10) W/m2. The mean SMR of infants aged 1-2 months was 38 compared with 44 W/m2 in infants of 8-12 months; the difference was not significant. There were no obvious differences in SMR between boys and girls. But there were wide differences in SMR between apparently similar infants, range 1.4 to 3.5 W/kg. Most parents selected insulation between 1 and 3 togs, and this was weakly negatively correlated with air temperature.

CONCLUSION

These wide variations in SMR mean that it is impossible to give specific guidelines on the amount of clothing and bedding a particular infant will need for thermal comfort in a given room temperature.

Individual variation in sleeping metabolic rates in infants

AIM

To measure the variation in sleeping metabolic rate (SMR) of healthy infants in the first year of life.

METHODS

Attempts were made to measure SMR in the home of one group of infants at monthly intervals over the first year of life and of another group in the 1 to 12 age range, over three consecutive days. Sixty one infants were recruited and 181 measurements made. In 11 infants six or more satisfactory measurements were made a monthly intervals and in another 11 infants, three consecutive daily measurements were obtained. Parents chose the clothing and bedding that they judged their infant needed to fall asleep. The room air and radiative temperatures, humidity, and amount of insulation were recorded.

RESULTS

The mean (SD) SMR was 2.4 (0.4) watts (W)/kg or 45 (10) W/m2. The rate was the same for infants in the age groups 0.25, 0.5, 0.75, and 1 years; individual infants did not show a systematic change with age. There was wide variation. Ninety eight per cent of infants had a SMR between 1.8 and 3.1 W/kg. The mean SMR for the infants measured on three consecutive days varied from 1.7 to 3.1 W/kg, and SMR varied within infants, from 0.06 to 0.86 W/kg. The variation within six to 11 measurements on infants over the first year of life ranged from 0.38 to 1.05 W/kg.

CONCLUSION

Infants in the first year of life exhibit wide variations in SMR from day to day and from month to month. As the range is wide, guidance on clothing and bedding for thermal comfort can be given only in broad terms.

Malignant lymphoma in congenital dyserythropoietic anaemia type III

A 60 year old woman with congenital dyserythropoietic anaemia (CDA) type III developed a malignant T cell lymphoma with cutaneous and widespread nodal involvement. Bone marrow aspirates showed erythroid hyperplasia and dyserythropoiesis with multinucleate erythroblasts and gigantoblasts, in keeping with CDA type III. Electron microscopy showed multinucleate erythroblasts with notably irregular nuclear outlines and intranuclear clefts. The development of malignant lymphoma in this patient, together with a documented high prevalence of monoclonal gammopathy and multiple myeloma and a single case of Hodgkin's disease, may indicate an increased incidence of lymphoproliferative disease in CDA type III.

Organ transplantation at the Hartford Transplant Center

Over 1,243 organ transplants have been performed at the Hartford Transplant Center over the past two decades. Survival in kidney, heart, liver, and pancreas patients is at or above the national average. Hartford was one of the first centers to use triple immunosuppression, which significantly improved survival in kidney transplantation. For recipients of kidneys from living related donors and cadaveric kidneys, two-year actuarial graft survival has been 98% and 83%, respectively, over the last five years. For heart and liver transplants, two-year survival has been 79% and 67%, respectively. Despite high success rates at most transplant centers, donor organs remain scarce. This problem needs to be addressed through increased cooperative efforts in the health-care community and the general public.

Health and immunology study following exposure to toxigenic fungi (Stachybotrys chartarum) in a water-damaged office environment

There is growing concern about adverse health effects of fungal bio-aerosols on occupants of water-damaged buildings. Accidental, occupational exposure in a nonagricultural setting has not been investigated using modern immunological laboratory tests. The objective of this study was to evaluate the health status of office workers after exposure to fungal bio-aerosols, especially Stachybotrys chartarum (atra) (S. chartarum) and its toxigenic metabolites (satratoxins), and to study laboratory parameters or biomarkers related to allergic or toxic human health effects. Exposure characterization and quantification were performed using microscopic, culture, and chemical techniques. The study population (n = 53) consisted of 39 female and 14 male employees (mean age 34.8 years) who had worked for a mean of 3.1 years at a problem office site; a control group comprised 21 persons (mean age 37.5 years) without contact with the problem office site. Health complaints were surveyed with a 187-item standardized questionnaire. A comprehensive test battery was used to study the red and white blood cell system, serum chemistry, immunology/antibodies, lymphocyte enumeration and function. Widespread fungal contamination of water-damaged, primarily cellulose material with S. chartarum was found. S. chartarum produced a macrocyclic trichothecene, satratoxin H, and spirocyclic lactones. Strong associations with exposure indicators and significant differences between employees (n = 53) and controls (n = 21) were found for lower respiratory system symptoms, dermatological symptoms, eye symptoms, constitutional symptoms, chronic fatigue symptoms and several enumeration and function laboratory tests, mainly of the white blood cell system. The proportion of mature T-lymphocyte cells (CD3%) was lower in employees than in controls, and regression analyses showed significantly lower CD3% among those reporting a history of upper respiratory infections. Specific S. chartarum antibody tests (IgE and IgG) showed small differences (NS). It is concluded that prolonged and intense exposure to toxigenic S. chartarum and other atypical fungi was associated with reported disorders of the respiratory and central nervous systems, reported disorders of the mucous membranes and a few parameters pertaining to the cellular and humoral immune system, suggesting a possible immune competency dysfunction.

Metabolic rate in febrile infants

An open circuit indirect calorimeter was used to measure resting energy expenditure in febrile infants. Twelve infants admitted to hospital with fever (axillary temperature 37.5 degrees C) were studied on admission and then again at the same time of day and in similar environmental conditions after the fever had resolved. Mean age of the infants was 0.31 years (range 0.12-0.54) and the mean body weight 6.59 kg (range 4.50-8.88 kg). On average the infants' axillary temperatures were +2.1 degrees C higher when they were febrile. Overall the mean difference in oxygen consumption (VO2), carbon dioxide production (VCO2), and resting energy expenditure (REE) between the febrile and afebrile measurements was not statistically significant. Of eight infants with a greater REE when febrile, five were diagnosed as having viral illness and three had bacterial meningitis. Of the four with a lower REE when febrile, two had viral illness and two had bacterial infection (one chest infection and one meningitis). In conclusion, there was no consistent alteration of REE during a fever in infants 1 to 6 months of age. In particular, age and type of infection were not predictors of whether REE would increase or decrease during the illness.