The tumor immune composition of mismatch repair deficient and Epstein-Barr virus-positive gastric cancer: A systematic review

BACKGROUND

Gastric cancer (GC), known for its unfavorable prognosis, has been classified in four distinct molecular subtypes. These subtypes not only exhibit differences in their genome and transcriptome but also in the composition of their tumor immune microenvironment. The microsatellite instable (MSI) and Epstein-Barr virus (EBV) positive GC subtypes show clear clinical benefits from immune checkpoint blockade, likely due to a neoantigen-driven and virus-driven antitumor immune response and high expression of immune checkpoint molecule PD-L1. However, even within these subtypes response to checkpoint inhibition is variable, which is potentially related to heterogeneity in the tumor immune microenvironment (TIME) and expression of co-inhibitory molecules. We conducted a systematic review to outline the current knowledge about the immunological features on the TIME of MSI and EBV + GCs.

METHODS

A systematic search was performed in PubMed, EMBASE and Cochrane Library. All articles from the year 1990 and onwards addressing immune features of gastric adenocarcinoma were reviewed and included based on predefined in- and exclusion criteria.

RESULTS

In total 5962 records were screened, of which 139 were included that reported immunological data on molecular GC subtypes. MSI and EBV + GCs were reported to have a more inflamed TIME compared to non-MSI and EBV- GC subtypes. Compared to microsatellite stable (MSS) tumors, MSI tumors were characterized by higher numbers of CD8 + and FoxP3 + T cells, and tumor infiltrating pro- and anti-inflammatory macrophages. HLA-deficiency was most common in MSI tumors compared to other molecular GC subtypes and associated with lower T and B cell infiltrates compared to HLA-proficient tumors. EBV + was associated with a high number of CD8 + T cells, Tregs, NK cells and macrophages. Expression of PD-L1, CTLA-4, Granzyme A and B, Perforin and interferon-gamma was enriched in EBV + tumors. Overall, MSI tumors harbored a more heterogeneous TIME in terms of immune cell composition and immune checkpoints compared to the EBV + tumors.

DISCUSSION AND CONCLUSION

MSI and EBV + GCs are highly Handbook for Conducting a Literature-Based Health Assessment Using OHAT Approach for Systematic Review and Evidence Integration.; 2019pro-inflammatory immune cell populations. Although studies on the direct comparison of EBV + and MSI tumors are limited, EBV + tumors show less intra-subgroup heterogeneity compared to MSI tumors. More studies are needed to identify how Intra-subgroup heterogeneity impacts response to immunotherapy efficacy.

Animal board invited review: The purebred-crossbred genetic correlation in poultry

The purebred-crossbred genetic correlation (rpc) is a key parameter to determine whether the optimal selection of purebred animals to improve crossbred performance should rely on crossbred phenotypes, purebred phenotypes, or both. We reviewed published estimates of the rpc in poultry. In total, 19 studies were included, of which four were on broilers and 15 on laying hens, with 150 rpc estimates for nine different trait categories. Average reported rpc estimates were highest for egg weight, egg quality and egg colour (0.74-0.82), intermediate for BW, maturity and mortality (0.61-0.70) and egg number (0.58), and low for resilience (0.40) and body conformation (0.14). Most studies were based on measuring purebred and crossbred phenotypes in the same environment and thus did not capture the contribution of genotype by environment interactions to the rpc, suggesting that the presented average estimates may be higher than values that apply in practice. Nearly all studies were based on two-way crossbred animals. We hypothesised that rpc values for a two-way cross are good proxies for rpc of a four-way cross. Only eight out of 19 studies were published in the last 25 years, and only two of those used genomic data. We expect that more studies using genomic data may be published in the coming years, as the required data may be generated when implementing genomic selection for crossbred performance, which will lead to more accurate rpc estimates. Future studies that aim to estimate rpc are encouraged to capture the genotype by environment interaction component by housing purebred and crossbred animals differently as is done in practice. Moreover, there is a need for further studies that enable to explicitly estimate the magnitude of genotype by environment versus genotype by genotype interactions for multiple trait categories. Further, studies are advised to report: the specific housing conditions of the animals, any differences between measurements of purebred versus crossbred performance, and the heritabilities of purebred and crossbred performance.

Uncertainty in phosphorus fluxes and budgets across the U.S. long-term agroecosystem research network

Phosphorus (P) budgets can be useful tools for understanding nutrient cycling and quantifying the effectiveness of nutrient management planning and policies; however, uncertainties in agricultural nutrient budgets are not often quantitatively assessed. The objective of this study was to evaluate uncertainty in P fluxes (fertilizer/manure application, atmospheric deposition, irrigation, crop removal, surface runoff, leachate) and the propagation of these uncertainties to annual P budgets. Data from 56 cropping systems in the P-FLUX database, which spans diverse rotations and landscapes across the U.S. and Canada, were evaluated. Results showed that across cropping systems, average annual P budget was 22.4 kg P ha^-1 (range = -32.7 to 340.6 kg P ha^-1 ), with an average uncertainty of 13.1 kg P ha^-1 (range = 1.0 to 87.1 kg P ha^-1 ). Fertilizer/manure application and crop removal were the largest P fluxes across cropping systems and, as a result, accounted for the largest fraction of uncertainty in annual budgets (61 and 37%, respectively). Remaining fluxes individually accounted for <2% of the budget uncertainty. Uncertainties were large enough that determining whether P was increasing, decreasing, or not changing was inconclusive in 39% of the budgets evaluated. Findings indicate that more careful and/or direct measurements of inputs, outputs, and stocks are needed. Recommendations for minimizing uncertainty in P budgets based on the results of the study were developed. Quantifying, communicating, and constraining uncertainty in budgets among production systems and multiple geographies is critical for engaging stakeholders, developing local and national strategies for P reduction, and informing policy. This article is protected by copyright. All rights reserved.

Assessment of COVID-19 outbreaks in long-term care facilities

BACKGROUND

The B.1.167.2 (Delta) variant quickly became the predominant circulating SARS-CoV-2 strain in the USA during summer 2021. Missouri identified a high number of outbreaks in long-term care facilities (LTCFs) across the state with low vaccination rates among LTCF staff members and poor adherence to mitigation measures within local communities.

AIM

To describe COVID-19 outbreaks that occurred in Missouri LTCFs impacting staff and residents during the surge of the Delta variant.

METHODS

Outbreaks of COVID-19 in 178 LTCFs were identified by the Missouri Department of Health and Senior Services. Case data from LTCFs with the highest burden of disease were analysed to assess disease transmission, vaccination status, and outcomes among residents and staff. Additional investigational measures included onsite visits to facilities with recent COVID-19 outbreaks in communities with substantial transmission to assess mitigation measures.

FINDINGS

During April 22^nd to July 29^th, 2021, 159 COVID-19 cases among 72 staff members and 87 residents were identified in 10 LTCFs. More than 74.7% of resident cases were vaccinated compared to 23.6% of staff cases. Vaccinated residents had a lower proportion of hospitalizations and deaths reported compared to unvaccinated residents. Data analysis and contact-tracing efforts from a sample of the facilities suggest that staff members were likely a major factor in introducing SARS-CoV-2 virus into the facilities. Adherence to COVID-19 mitigation measures varied at the visited facilities.

CONCLUSION

Data showed that vaccination rates varied between staff cases and resident cases in facilities with high-burden outbreaks. Differences were identified in mitigation practices in at least two facilities.

P-FLUX: A phosphorus budget dataset spanning diverse agricultural production systems in the United States and Canada

Quantifying spatial and temporal fluxes of phosphorus (P) within and among agricultural production systems is critical for sustaining agricultural production while minimizing environmental impacts. To better understand P fluxes in agricultural landscapes, P-FLUX, a detailed and harmonized dataset of P inputs, outputs, and budgets, as well as estimated uncertainties for each P flux and budget, was developed. Data were collected from 24 research sites and 61 production systems through the Long-term Agroecosystem Research (LTAR) network and partner organizations spanning 22 U.S. states and 2 Canadian provinces. The objectives of this paper are to (a) present and provide a description of the P-FLUX dataset, (b) provide summary analyses of the agricultural production systems included in the dataset and the variability in P inputs and outputs across systems, and (c) provide details for accessing the dataset, dataset limitations, and an example of future use. P-FLUX includes information on select site characteristics (area, soil series), crop rotation, P inputs (P application rate, source, timing, placement, P in irrigation water, atmospheric deposition), P outputs (crop removal, hydrologic losses), P budgets (agronomic budget, overall budget), uncertainties associated with each flux and budget, and data sources. Phosphorus fluxes and budgets vary across agricultural production systems and are useful resources to improve P use efficiency and develop management strategies to mitigate environmental impacts of agricultural systems. P-FLUX is available for download through the USDA Ag Data Commons (https://doi.org/10.15482/USDA.ADC/1523365).

[Online schema therapy: a cross-sectional survey among Dutch therapists]

BACKGROUND

Long waiting lists exist for the treatment of personality disorders, which can be shortened by using videoconference treatment. During the COVID-19 pandemic, by necessity, videoconferencing was used to provide schema therapy, a specific treatment for personality disorders.

AIM

To investigate therapist experience of schema therapy via videoconferencing during the pandemic.

METHOD

In an observational cross-sectional study, 83 schema therapists completed a questionnaire about the period prior to, and during the COVID-19 pandemic. We investigated their experience, use of, and attitude toward videoconferencing, as well as the extent to which the effectiveness of videoconferencing and face to face (F2F) schema therapy for personality disorders was found to be comparable.

RESULTS

Schema therapists rated their experience with videoconferencing therapy for personality disorders during the COVID-19 pandemic positively, its use increased during this period, and therapists&rsquo; attitudes became more positive. However, the majority found videoconferencing therapy less effective than F2F treatment. Almost half of the therapists used shorter sessions or adapted exercises during videoconferencing therapy.

CONCLUSION

Although therapists were increasingly positive about video conferencing therapy, they believed that F2F treatment is more effective. Randomized efficacy studies of videoconferencing therapy compared to F2F therapy are needed, also examining patients&rsquo; experiences with both forms.

A comprehensive approach to ending an outbreak of rare blaOXA-72 gene-positive carbapenem-resistant Acinetobacter baumannii at a Community Hospital, Kansas City, MO, 2018

We identified a cluster of extensively drug-resistant, carbapenemase gene-positive, carbapenem-resistant Acinetobacter baumannii (CP-CRAB) at a teaching hospital in Kansas City. Extensively drug-resistant CRAB was identified from eight patients and 3% of environmental cultures. We used patient cohorting and targeted environmental disinfection to stop transmission. After implementation of these measures, no additional cases were identified.

Ektacytometry Analysis of Post-splenectomy Red Blood Cell Properties Identifies Cell Membrane Stability Test as a Novel Biomarker of Membrane Health in Hereditary Spherocytosis

Hereditary spherocytosis (HS) is the most common form of hereditary chronic hemolytic anemia. It is caused by mutations in red blood cell (RBC) membrane and cytoskeletal proteins, which compromise membrane integrity, leading to vesiculation. Eventually, this leads to entrapment of poorly deformable spherocytes in the spleen. Splenectomy is a procedure often performed in HS. The clinical benefit results from removing the primary site of destruction, thereby improving RBC survival. But whether changes in RBC properties contribute to the clinical benefit of splenectomy is unknown. In this study we used ektacytometry to investigate the longitudinal effects of splenectomy on RBC properties in five well-characterized HS patients at four different time points and in a case-control cohort of 26 HS patients. Osmotic gradient ektacytometry showed that splenectomy resulted in improved intracellular viscosity (hydration state) whereas total surface area and surface-to-volume ratio remained essentially unchanged. The cell membrane stability test (CMST), which assesses the in vitro response to shear stress, showed that after splenectomy, HS RBCs had partly regained the ability to shed membrane, a property of healthy RBCs, which was confirmed in the case-control cohort. In particular the CMST holds promise as a novel biomarker in HS that reflects RBC membrane health and may be used to asses treatment response in HS.

Re-do left cardiac sympathetic denervation (LCSD following breakthrough cardiac events in long qt syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT)

Background

Left cardiac sympathetic denervation (LCSD) is an effective anti-fibrillatory, minimally invasive therapy for patients with either LQTS or CPVT. As a pre-ganglionic fiber resection, re-growth or re-innervation is not possible. However, if a suboptimal CSD was performed, chances for post-LCSD breakthrough cardiac events (BCEs) are increased.

Purpose

To examine the prevalence and outcomes of patients requiring a re-do LCSD.

Methods

We performed a retrospective review of the 251 LQTS and CPVT patients who underwent CSD (mostly LCSD) at our institution to identify the subset referred for additional CSD because of recurrent BCEs after their primary LCSD that was performed elsewhere. Clinical data on symptomatic status prior to diagnosis and BCEs after first surgery as well as the surgical reports were reviewed to determine the reasons for the repeat procedure.

Results

Among the 15 patients (6% overall, 6 female; 13 LQTS, 2 CPVT) referred for additional CSD, 3 patients (20%) had a re-do LCSD performed instead of a sequential RCSD because of incomplete resection with the primary LCSD. Patient 1 is a male with Jervell-and-Lange Nielsen Syndrome (JLNS; KCNQ1-K421fs9X; KCNQ1-N365H), who first experienced syncope with torsades at age 3 after which a primary bilateral CSD was performed elsewhere. He had 2 BCEs and at age 12 underwent re-do LCSD, where his left-sided T2-T4 sympathetic chain with remnants of T1 were found to be intact. Patient 2 is a male who had 3 cardiac events prior to diagnosis (genotype negative LQTS) and LCSD at age 3. Following 3 BCEs, he underwent re-do LCSD at age 5 where scarring of T3 and intact stellate ganglion were found. Patient 3 is an adult female with CPVT (RYR2-deletion exon 3) who had multiple syncopal events, out-of-hospital arrest (leading to ICD) and 2 ICD-storms before primary bilateral CSD. Re-do LCSD was performed after identifying an intact left stellate ganglion and T2.

Conclusions

Before performing a primary bilateral CSD, proceeding to a RCSD after post-LCSD BCEs, or doing a videoscopic LCSD in the first place, it must be recognized that LCSD's success hinges on fully resecting the lower half of the stellate ganglion and the sympathetic chain through T4. Anything less is a partial denervation and likely ineffective procedure.

Funding Acknowledgement

Type of funding source: None

T cell-derived interferon-γ programs stem cell death in immune-mediated intestinal damage

Despite the importance of intestinal stem cells (ISCs) for epithelial maintenance, there is limited understanding of how immune-mediated damage affects ISCs and their niche. We found that stem cell compartment injury is a shared feature of both alloreactive and autoreactive intestinal immunopathology, reducing ISCs and impairing their recovery in T cell-mediated injury models. Although imaging revealed few T cells near the stem cell compartment in healthy mice, donor T cells infiltrating the intestinal mucosa after allogeneic bone marrow transplantation (BMT) primarily localized to the crypt region lamina propria. Further modeling with ex vivo epithelial cultures indicated ISC depletion and impaired human as well as murine organoid survival upon coculture with activated T cells, and screening of effector pathways identified interferon-γ (IFNγ) as a principal mediator of ISC compartment damage. IFNγ induced JAK1- and STAT1-dependent toxicity, initiating a proapoptotic gene expression program and stem cell death. BMT with IFNγ-deficient donor T cells, with recipients lacking the IFNγ receptor (IFNγR) specifically in the intestinal epithelium, and with pharmacologic inhibition of JAK signaling all resulted in protection of the stem cell compartment. In addition, epithelial cultures with Paneth cell-deficient organoids, IFNγR-deficient Paneth cells, IFNγR-deficient ISCs, and purified stem cell colonies all indicated direct targeting of the ISCs that was not dependent on injury to the Paneth cell niche. Dysregulated T cell activation and IFNγ production are thus potent mediators of ISC injury, and blockade of JAK/STAT signaling within target tissue stem cells can prevent this T cell-mediated pathology.

2458. A comprehensive approach to ending an outbreak of rare OXA-72 producing carbapenem-resistant Acinetobacter baumannii at a Community Hospital, Kansas City, MO, 2018

Background

In 2018, an outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) containing a rare β-lactamase (OXA-72) was detected at Research Medical Center, a 511 bed community hospital in Kansas City, MO. We describe a coordinated effort among hospital infection control personnel and public health to control the outbreak.

Methods

We defined a case as isolation of OXA-72-producing CRAB from any clinical culture collected from a hospitalized patient during 2018. We assessed infection control practices, including adherence to transmission-based precautions and hand hygiene, environmental cleaning and patient transfers. After patients with CRAB were discharged, terminal cleaning was performed using bleach and environmental cultures were collected; rooms were closed to new patients until CRAB was not isolated. Whole-genome sequencing and bioinformatics analyses were performed.

Results

From January through October, CRAB was isolated from clinical cultures among 20 patients; 6 OXA-72-positive cases were identified during June and July. We found practices for cleaning and disinfection of shared medical equipment were not clearly delineated among nursing and environmental services staff and we ensured responsibilities were well defined. W restricted all patients with CRAB to certain medical units in order to limit the spread. In total, 248 environmental cultures were collected; 151 (61%) from inside patient rooms and 97 (39%) from shared medical equipment or surfaces outside patient rooms. Overall, Acintobacter baumannii was isolated from 39 (16%) environmental cultures (21 from inside rooms and 18 from outside rooms); 5 isolates were confirmed to contain OXA-72. Using WGS, we compared 6 clinical and 5 environmental OXA-72 CRAB isolates; all were determined to be genetically related (0–6 single nucleotide polymorphisms, 88.4% core genome) (figure). No additional cases were identified after these interventions.

Conclusion

We identified widespread CRAB environmental contamination, illustrating the challenges of eradicating CRAB from the hospital environment. We developed a comprehensive approach focusing on infection control, environmental cleaning and culturing, and patient movement to stop the outbreak.

Disclosures

All authors: No reported disclosures.

Quality control for the first large areas of triple-GEM chambers for the CMS endcaps

The CMS Collaboration plans to equip the very forward muon system with triple-GEM detectors that can withstand the environment of the High-Luminosity LHC. This project is at the final stages of R&D and moving to production. An unprecedented large area of several 100 m2 are to be instrumented with GEM detectors which will be produced in six different sites around the world. A common construction and quality control procedure is required to ensure the performance of each detector. The quality control steps will include optical inspection, cleaning and baking of all materials and parts used to build the detector, leakage current tests of the GEM foils, high voltage tests, gas leak tests of the chambers and monitoring pressure drop vs. time, gain calibration to know the optimal operation region of the detector, gain uniformity tests, and studying the efficiency, noise and tracking performance of the detectors in a cosmic stand using scintillators.

A novel application of Fiber Bragg Grating (FBG) sensors in MPGD

We present a novel application of Fiber Bragg Grating (FBG) sensors in the construction and characterisation of Micro Pattern Gaseous Detector (MPGD), with particular attention to the realisation of the largest triple (Gas electron Multiplier) GEM chambers so far operated, the GE1/1 chambers of the CMS experiment at LHC. The GE1/1 CMS project consists of 144 GEM chambers of about 0.5 m2 active area each, employing three GEM foils per chamber, to be installed in the forward region of the CMS endcap during the long shutdown of LHC in 2108-2019. The large active area of each GE1/1 chamber consists of GEM foils that are mechanically stretched in order to secure their flatness and the consequent uniform performance of the GE1/1 chamber across its whole active surface. So far FBGs have been used in high energy physics mainly as high precision positioning and re-positioning sensors and as low cost, easy to mount, low space consuming temperature sensors. FBGs are also commonly used for very precise strain measurements in material studies. In this work we present a novel use of FBGs as flatness and mechanical tensioning sensors applied to the wide GEM foils of the GE1/1 chambers. A network of FBG sensors have been used to determine the optimal mechanical tension applied and to characterise the mechanical tension that should be applied to the foils. We discuss the results of the test done on a full-sized GE1/1 final prototype, the studies done to fully characterise the GEM material, how this information was used to define a standard assembly procedure and possible future developments.

Measles outbreak associated with adopted children from China--Missouri, Minnesota, and Washington, July 2013

On July 5, 2013, CDC was notified of two cases of laboratory-confirmed measles in recently adopted children from an orphanage in Henan Province, China. To find potentially exposed persons, CDC collaborated with state and local health departments, the children's adoption agency, and airlines that carried the adoptees. Two additional measles cases were identified, one in a family member of an adoptee and one in a third adopted child from China. To prevent further importation of measles, CDC worked with health officials in China, including "panel physicians" contracted by the U.S. Department of State to conduct the overseas medical examinations required for all immigrants and refugees bound for the United States. The following measures were recommended: 1) all adoptees examined at panel physician facilities should be screened for fever and rash illness, 2) measles immunity should be ensured among all adoptees from Henan Province who are scheduled for imminent departure to the United States, and 3) all children at the orphanage in Henan Province should be evaluated for measles. This report summarizes the results of the outbreak investigation and underscores the importance of timely routine vaccination for all international adoptees.

Necrotizing cutaneous mucormycosis after a tornado in Joplin, Missouri, in 2011

BACKGROUND

Mucormycosis is a fungal infection caused by environmentally acquired molds. We investigated a cluster of cases of cutaneous mucormycosis among persons injured during the May 22, 2011, tornado in Joplin, Missouri.

METHODS

We defined a case as a soft-tissue infection in a person injured during the tornado, with evidence of a mucormycete on culture or immunohistochemical testing plus DNA sequencing. We conducted a case-control study by reviewing medical records and conducting interviews with case patients and hospitalized controls. DNA sequencing and whole-genome sequencing were performed on clinical specimens to identify species and assess strain-level differences, respectively.

RESULTS

A total of 13 case patients were identified, 5 of whom (38%) died. The patients had a median of 5 wounds (range, 1 to 7); 11 patients (85%) had at least one fracture, 9 (69%) had blunt trauma, and 5 (38%) had penetrating trauma. All case patients had been located in the zone that sustained the most severe damage during the tornado. On multivariate analysis, infection was associated with penetrating trauma (adjusted odds ratio for case patients vs. controls, 8.8; 95% confidence interval [CI], 1.1 to 69.2) and an increased number of wounds (adjusted odds ratio, 2.0 for each additional wound; 95% CI, 1.2 to 3.2). Sequencing of the D1-D2 region of the 28S ribosomal DNA yielded Apophysomyces trapeziformis in all 13 case patients. Whole-genome sequencing showed that the apophysomyces isolates were four separate strains.

CONCLUSIONS

We report a cluster of cases of cutaneous mucormycosis among Joplin tornado survivors that were associated with substantial morbidity and mortality. Increased awareness of fungi as a cause of necrotizing soft-tissue infections after a natural disaster is warranted.

[Quality of life in dementia, opinions among people with dementia, their professional caregivers, and in literature]

Different definitions of quality of life (QOL) are found in the literature. This raised the question which domains are viewed as really important by persons with dementia. In an explorative study the opinions of persons with dementia (community-dwelling and living in nursing homes), were compared to those of professional carers and instruments for QOL in dementia. Data were gathered through interviews, focus groups and literature study. Most QOL-domains mentioned as important by persons with dementia were also acknowledged by carers and in measurement instruments. Some domains, however, were not mentioned by the carers ('sense of aesthetics', 'financial situation', 'being useful' and 'spirituality'), or not selected in the measuring instruments ('security and privacy', 'self-determination and freedom', 'being useful' and 'spirituality'). This indicates differences in perspectives on quality of life between persons with dementia, professional caregivers and researchers. Subsequently it was studied to what degree professionals focus on the QoL-domains that persons with dementia consider essential. Caregivers working on 29 units and 3 day care facilities of 13 nursing homes and in 12 meeting centers filled out a questionnaire (N = 374). They reported to focus at least to some degree on most domains considered important by persons with dementia. However, little attention was paid to the domains 'financial situation' and 'being useful'. Professionals offering daytime activities focused more than 24-hour care staff on 'attachment', 'enjoyment of activities', 'sense of aesthetics', and 'being useful'. This article is a translation and merging of 1) Dröes et al. Quality of life in dementia in perspective; an explorative study of variations in opinions among people with dementia and their professional caregivers, and in literature. Dementia: The International Journal 2006; 5 (4): 533-558, and 2) Gerritsen et al. Differences in perspective: do professional caregivers focus on the Quality of life domains that are important for people with dementia? American Journal of Alzheimer's Disease and Other Dementias 2007; 22:176-183.

Ascorbic acid and infectious bronchitis infections in broilers

The effect of supplementing the feed of broiler chicks with different levels of ascorbic acid on the resistance against infectious bronchitis virus was investigated. Resistance was measured by the severity of tracheal lesions and the development of airsacculitis after challenge. The effect of ascorbic acid was dose dependent. Addition of 300 to 330 ppm ascorbic acid to the feed gave the best results. High concentrations (>600 ppm) had a less beneficial effect.

Update on hantavirus in Oklahoma: are we missing cases?

Hantavirus Pulmonary Syndrome (HPS) was first recognized in 1993. Through July 6, 2005, 396 cases have been reported in the US, including 50 from Kansas, Texas, and Oklahoma. We report the second case of HPS in Oklahoma and present data from rodent testing to support the presence of hantaviruses across Oklahoma. We examined Oklahoma death certificates for 1999-2003 for possible unreported HPS cases. The rate of death in young adults 15-49 years due to acute respiratory distress syndrome was 69% higher and the death rate due to unspecified respiratory failure was three times higher in the grassland area of Oklahoma as compared to the non-grassland. It appears the highest risk of HPS is in the Oklahoma grasslands but Sin Nombre virus is present in the non-grassland area as well. We request physician collaboration in detection and reporting of HPS cases and present brief recommendations for prevention.

Equine trypanosomosis in the Central River Division of The Gambia: a study of veterinary gate-clinic consultation records

The objective of this study was to provide epidemiological information of equine trypanosomosis in the Central River Division (CRD) of The Gambia. Therefore, 2285 consultations records of equines, admitted in a gate-clinic at Sololo in CRD, were studied retrospectively. The data were recorded in the period between September 1995 and July 2002 and comprised consultations of 2113 horses and 172 donkeys. 'Trypanosome infection' was the most frequently diagnosed condition and accounted for 61% of the cases. Horses were more frequently diagnosed with trypanosome infections than donkeys (p<0.001), with an occurrence of 63% compared to 43% in donkeys. In both horses and donkeys, trypanosome infections were mainly due to Trypanosoma congolense (64%) and T. vivax (32%). There was no difference observed in the occurrence of trypanosome infections in male or female donkeys (p=0.585), but there were more female (67.8%) horses observed with trypanosome infections than male horses (60.7%; p=0.003). There was no difference observed in the occurrence of trypanosome infections in donkeys older or younger than 1 year (p=0.130), but more older horses (63.2% >1 year) were observed with trypanosome infections than young horses (54.5% <1 year; p=0.033). The number of donkeys and horses with trypanosome infections decreased during the rainy season (June-September). The majority of equines that were admitted with trypanosome infections were severely anaemic. The average packed cell volume (PCV) declined with increasing parasitaemia (p=0.006). Seventy-four percent of the farmers' predictions of trypanosome infections in their equines were confirmed by darkground-microscopy. That proved that farmers had a fairly accurate knowledge of the diseases affecting their equines. The treatments executed at the gate-clinic were generally effective. The few (0.4%) relapses of the T. vivax infections that were previously treated with diminazene aceturate in this study were not sufficient to prove drug resistance. The study showed that the analysis of consultation records at a gate-clinic can provide complementary information to conventional epidemiological studies in the same research area.

Susceptibility of West African Dwarf goats and WAD×Saanen crosses to experimental infection with Trypanosoma congolense

West African Dwarf goats (WADs) and their Saanen crosses were experimentally infected with Trypanosoma congolense. No significant differences were found between trypanosome parasitaemia and antibody response of the crossbred and WAD goats. Neither the WAD goats nor the Saanen crosses were able to control the drop in PCV following trypanosome infection. The level of anaemia caused by the trypanosome infection was similar in the two breeds during the trial. Based on these findings, no difference in tolerance or susceptibility to T. congolense could be demonstrated between the WAD goats and their Saanen crosses. Although the weight of all goats increased during the trial, the crosses gained significantly more weight than the WAD goats. The trypanosome infection reduced the growth rate of both breeds, but this reduction was not statistically significant. Crossbreeding trypanotolerant WADs with trypanosusceptible Saanen goats might, therefore, be an effective means of increasing productivity.

Fatal necrotizing colitis following a foodborne outbreak of enterotoxigenic Clostridium perfringens type A infection

BACKGROUND

Enterotoxigenic Clostridium perfringens type A is the third leading cause of foodborne disease in the United States, resulting annually in an estimated 250,000 cases of a typically mild, self-limiting gastrointestinal illness.

METHODS

A retrospective cohort study was conducted to determine the cause of a small cluster of cases of gastrointestinal illness, which included cases of severe necrotizing colitis. Participants in the study consisted of residents and staff of a residential care facility for the mentally ill in Oklahoma (n = 20). An inspection of food preparation and food storage areas of the residential care facility was conducted as part of an environmental investigation. The investigation included extensive microbiological and molecular testing of the C. perfringens isolates and tissue specimens collected at autopsy.

RESULTS

A total of 7 (3 confirmed and 4 probable) cases of foodborne enterotoxigenic C. perfringens type A were identified (attack rate, 35%) after the consumption of high-risk foods. Three residents developed acute necrotizing colitis; 2 of them died. Each patient with confirmed infection presented with evidence of constipation or fecal impaction. C. perfringens enterotoxin (CPE)-positive C. perfringens type A was cultured on samples from each patient with necrotizing colitis. Although statistical analyses failed to implicate a food source, the isolates carried a chromosomal cpe gene, which supports a foodborne origin.

CONCLUSIONS

This study confirms that foodborne CPE-positive C. perfringens type A can affect the colon, resulting in potentially fatal necrotizing colitis. Drug-induced constipation and fecal impaction, resulting in prolonged exposure of the colonic mucosal tissue to C. perfringens type A toxins, contributed to the development of necrotizing colitis.

Definition and assessment of specific occupational demands concerning lifting, pushing, and pulling based on a systematic literature search

AIMS

(1) To find a universal strategy for the identification of specific demands of a job or task, focusing on occupations in which there may be an increased risk for health complaints owing to these specific demands. (2) To select reliable and valid tests concerning lifting, pushing, and pulling, which consider the relation between occupational work demands and the assessment of the maximally acceptable load on an individual level.

METHODS

Literature search was performed using Medline (1988 to May 2001), Embase (1966 to May 2001), and NIOSHTIC (1971-98).

RESULTS

No universal strategy was found for the definition of specific occupational demands. Therefore a "three step strategy" was formulated for defining specific occupational demands in a job or a task in order to prevent health complaints on an individual level. Many tests were found in the literature concerning lifting, but only a few concerning pushing and pulling. None of the tests concerning pushing, pulling, or lifting considered the relation between work demands and the assessment of the maximally acceptable load on an individual level. Furthermore, none of the tests met the criteria of reliability and prognostic value for musculoskeletal complaints completely. Only for the prognostic value of relative strength capacity tests concerning pushing pulling and lifting, did there appear to be limited proof for the development of musculoskeletal complaints.

CONCLUSIONS

In general, for the prevention of work related health complaints, it can be suggested that more attention should be paid to: (1) the definition of specific occupational demands; (2) the assessment of specific occupational demands; and (3) the quality of tests for specific occupational demands.

Effects of diesel exhaust enriched concentrated PM2.5 in ozone preexposed or monocrotaline-treated rats

Epidemiological studies have observed statistical associations between short-term exposure to increased ambient particulate air pollution and increased hospital admissions, medication use, pulmonary morbidity, and mortality. To examine the effects of particle air pollution in animals, rats with a preexisting pulmonary inflammation (induced by 1600 microg/m(3) ozone) or hypertension (induced by monocrotaline, MCT) were nose-only exposed to concentrated freshly generated diesel exhaust particles (DEP) mixed with ambient air (CDP). It was hypothesized that a single 6-h exposure to PM exacerbates respiratory inflammatory processes, which affects health parameters in the blood. Histopathology of lung and nose, bronchiolar lavage (BAL), and blood analyses were performed at 1, 2, and 4 days after of the CDP exposure. Morphometry of BrdU-labeled cells in lung and nose was performed at 4 days postexposure. One day after ozone exposure, a mild inflammatory reaction in the centriacinar area was present, consisting of an increase in cellularity of septa and in the number of alveolar macrophages, decreasing in time. Additional CDP exposure did not influence this pattern, except for alveolar macrophages that were loaded with CDP. The only effect seen in the nose after ozone exposure was a slight hypertrophy of the septal mucous cells. Additional exposure to CDP did not change this appearance. MCT-treated rats showed hypertrophy of the media of the pulmonary muscular arteries that was not effected by CDP. BrdU labeling of predominantly Clara cells in the terminal bronchioles was significantly increased after ozone exposure as well as after MCT treatment, whereas this labeling index was markedly enhanced after an additional exposure to CDP. However, no increases in Clara cell protein (CC16) levels were measured of Clara cell protein (CC16) in either BAL or blood. BrdU labeling in the nasal epithelium was not influenced by exposure to ozone or ozone + CDP. CDP exposures did not induce significant toxic effects in the lungs. CDP exposures clearly induced an oxidative stress that was indicated by increasing glutathione levels in BAL with time. In addition, blood fibrinogen levels were enhanced in pulmonary hypertensive rats exposed to CDP. The present study demonstrates that very high CDP concentrations are needed to result in pulmonary changes in animal models with a preexisting pulmonary inflammation or hypertension that continue for days after a single exposure. In addition, CDP has the potential to induce changes in blood. It has not yet been determined how the effects seen with CDP would compare to similar levels of ambient particles.

Dilation of the sinotubular junction causes aortic insufficiency after aortic valve replacement with the Toronto SPV bioprosthesis

OBJECTIVE

This study was undertaken to examine the causes of late aortic insufficiency in patients who had aortic valve replacement with the Toronto SPV bioprosthesis (St Jude Medical, Inc, St Paul, Minn).

METHODS

From 1991 to 1996, 174 patients with a mean age of 63 +/- 11 years underwent aortic valve replacement with the Toronto SPV bioprosthesis and were evaluated annually by Doppler echocardiographic studies to assess valve function. The diameters of the aortic root were retrospectively measured in all patients who had aortic insufficiency and also in a random sample of 23 patients without aortic insufficiency. The mean follow-up was 5.8 years (range 4 to 9 years).

RESULTS

Aortic insufficiency greater than 1+ developed in 19 patients. The diameter of the sinotubular junction increased in these patients and did not change in those without aortic insufficiency. The ratio between the diameter of the sinotubular junction and the size of the Toronto SPV bioprosthesis increased in patients who had aortic insufficiency and did not change in those without aortic insufficiency. Both 2-way analysis of covariance and analysis by a mixed linear model demonstrated a significant difference in slopes between the patients with aortic insufficiency greater than 1+ and in those without insufficiency for the ratio of the diameter of the sinotubular junction/diameter of the Toronto SPV relationships over time (aortic insufficiency. Year; P <.001). Structural valve deterioration was observed in 5 valves, and in 4 of them the sinotubular junction of the aortic root had dilated. The freedom from structural valve deterioration was 99% +/- 1% for patients without aortic insufficiency and 82% +/- 12% for those with aortic insufficiency of more than 1+ at 8 years (P =.004). One patient had moderate aortic insufficiency without structural valve deterioration and dilation of the sinotubular junction.

CONCLUSIONS

Dilation of the sinotubular junction causes aortic insufficiency after aortic valve replacement with the Toronto SPV bioprosthesis and increases the risk of structural valve deterioration. Banding the sinotubular junction may prevent dilation and enhance the durability of this valve.

Surfactant chain length effects on the light emission of tris(2,2'-bipyridyl)ruthenium(II)/ tripropylamine electrogenerated chemiluminescence

The effects of nonionic surfactant chain length on the properties of tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3(2+) where bpy = 2,2'-bipyridine) electrochemiluminescence (ECL) have been investigated. The electrochemistry, photophysics, and ECL of Ru(bpy)3(2+) in the presence of a series of nonionic surfactants are reported (Triton X-100, 114, 165, 405, 305, and 705-70). These surfactants differ in the number of poly(ethylene oxide) units incorporated into the surfactant molecule. The anodic oxidation of Ru(bpy)3(2+) produces ECL in the presence of tri-n-propylamine (TPrA) in aqueous surfactant solution. Increases in ECL efficiency (> or = 5-fold) and TPrA oxidation current (> or = 2-fold) have been observed in surfactant media. Slight decreases in ECL intensity are observed as the chain length of the nonionic surfactant increases. The data supports adsorption of surfactant on the electrode surface, thus facilitating TPrA and Ru(bpy)3(2+) oxidation and leading to higher ECL efficiencies.

Notes on a controversy: the question of lay analysis

The question of lay analysis was one of the most important problems of pre-war psychoanalysis. The controversy began in the late 1910s and ended some 20 years later, in the late 1930s, without being resolved. The 1927 discussion on lay analysis marked the height of the controversy. This discussion also proved to be an important turning point, particularly when two rival attempts were made to settle the dispute.

Making a contribution to the history of psychoanalysis, this paper provides a detailed analysis of this controversy in terms of Bourdieu's work on symbolic capital. The author examines why the problem of lay analysis was never resolved, and links an explanation of this question to the inherent discursive dynamics of the debate. Psychoanalytic institutionalization, it is argued, goes hand in hand with an accumulation of symbolic capital, setting in motion processes of formalization of psychoanalytic discourse and of social distancing between speaker and listener.

Work-based antipoverty programs for parents can enhance the school performance and social behavior of children

We assess the impact of the New Hope Project, an antipoverty program tested in a random assignment experimental design, on family functioning and developmental outcomes for preschool- and school-aged children (N = 913). New Hope offered wage supplements sufficient to raise family income above the poverty threshold and subsidies for child care and health insurance to adults who worked full-time. New Hope had strong positive effects on boys' academic achievement, classroom behavior skills, positive social behavior, and problem behaviors, as reported by teachers, and on boys' own expectations for advanced education and occupational aspirations. There were not corresponding program effects for girls. The child outcomes may have resulted from a combination of the following: Children in New Hope families spent more time in formal child care programs and other structured activities away from home than did children in control families. New Hope parents were employed more, had more material resources, reported more social support, and expressed less stress and more optimism about achieving their goals than did parents in the control sample. The results suggest that an anti-poverty program that provides support for combining work and family responsibilities can have beneficial effects on the development of school-age children.

Personality characteristics of ADHD adults assessed with the Millon Clinical Multiaxial Inventory-II: evidence of four distinct subtypes

This study compared the personality characteristics of 104 adults diagnosed with attention deficit hyperactivity disorder (ADHD). Personality features were assessed with the MCMI-II (Millon, 1987). Participants were divided into 4 groups based on the presence of persisting oppositional defiant disorder (ODD) or other comorbid diagnoses (ADHD only, ADHD-comorbid, ADHD-ODD, ADHD-ODD-comorbid). Significant differences between these groups were present for 9 of the 13 MCMI-II personality scales, resulting in 4 modal personality styles. ADHD-only adults evidenced mild histrionic traits, whereas the ADHD-comorbid group was more often avoidant and dependent in personality style. ADHD-ODD adults showed histrionic, narcissistic, aggressive-sadistic, and negativistic traits whereas the ADHD-ODD-comorbid group had a combination of avoidant, narcissistic, antisocial, aggressive-sadistic, negativistic, and self-defeating personality features. Implications for treatment are discussed.

Shared life narratives in the work of Lou Andreas-Salomé

The author presents a re-reading of the works of Lou Andreas-Salomé (1861-1937), one of the key figures in the early history of psychoanalysis. He focusses in particular on her biographical and autobiographical works, as well as her correspondences with Freud, Rilke and other influential people of her time, arguing that Andreas-Salomé disappears from her own works as an autonomous speaking subject, while reappearing in the works of others as a silent, tacit influence. On closer examination, a specific genre emerges from her works that has so far gone unnoticed: the shared life narrative. The author claims that Andreas-Salomé developed this genre of shared life narratives in an attempt to match her theoretical notions of narcissism to a practical communicative position that is neither subjectivistic nor objectivistic. Relating the notion of shared life narratives to the psychoanalytic discourse, new possibilities may be opened up for expanding and enlarging our knowledge of human interaction.

Aortic valve replacement with stentless porcine aortic valve: a pioneer series

Durability of stentless porcine aortic valves is determined by the resistance of the cusps to mechanical fatigue and reactions by the host. This study examines the role of mismatch between the size of the valve and the diameter of the sinotubular junction on durability of the valve. A custom-made stentless porcine aortic valve designed for implantation in the subcoronary position was used for aortic valve replacement in 29 patients. There were 15 men and 14 women, with a mean age of 58 years (range 26 to 72 years). In addition to aortic valve replacement, 6 patients had mitral valve surgery, 10 patients had coronary artery bypass graft, 1 patient had closure of an atrial septal defect, and 1 had concomitant aortobi-iliac bypass graft. Follow-up time extended from 10.3 to 11.5 years and was complete. The selection of size of valve implanted was based solely on the diameter of the aortic annulus. Because the diameter of the sinotubular junction plays an important role in leaflet motion and valve competence, the size of valves was compared with the diameter of the sinotubular junction of the aortic roots where they were implanted. There was one operative death and five late deaths. There were no valve-related deaths. The actuarial survival at 10 years was 76%+/-5%. There were only two transient ischemic attacks and no strokes. One patient developed endocarditis 4 years' postoperatively and was successfully treated with aortic valve re-replacement. One patient with cardiomyopathy had heart transplantation. Thus, the stentless valve was at risk of failure in 21 patients. Nine patients developed echocardiographic evidence of valve dysfunction: seven had aortic valve re-replacement and two continue to be observed because the dysfunction is not severe. The function of the stentless valve remained normal in 12 patients. Patients with bioprosthetic valve dysfunction had a sinotubular junction 3.2+/-1.3 mm larger than the size of the valve, whereas patients with normal bioprosthetic valve function had a sinotubular junction 0.8+/-1.2 mm larger than the size of the valve (P = .01). The durability of stentless porcine aortic valve implanted in the subcoronary position is affected by discrepancies in diameters between the xenograft valve and the sinotubular junction of the aortic root. Sinotubular junction greater than the size of the stentless valve probably increases mechanical stress on the cusps and causes premature valve failure.

The Toronto SPV: hemodynamic data at 1 and 5 years' postimplantation

The Toronto-SPV (T-SPV) bioprosthesis has been used for aortic valve replacement (AVR) since July 1991. There is no published data on its mid-term hemodynamic performance. This study compares the hemodynamic data of a consecutive series of patients at 1 and 5 years after AVR. The first 109 consecutive patients who had AVR with a T-SPV have been monitored for a minimum of 5 years and have had annual Doppler echocardiographic studies. There were 80 men and 29 women in the study; mean age was 62 years (range 34 to 80 years). Concomitant coronary artery bypass surgery was done in 35 patients. One operative and nine late deaths occurred. The mean systolic gradient across the T-SPV in all patients was 3.9+/-2.4 mm Hg at 1 year and 4.1+/-3.3 mm Hg at 5 years (P = .27). The mean aortic valve area was 2.2+/-0.6 cm2 at 1 year and 2.3+/-0.7 cm2 at 5 years (P = .43). The mean left ventricular mass index (LVMI) was 104+/-31 g/m2 at 1 year and 97+/-24 g/m2 at 5 years (P = .08). Multivariate linear regression analysis showed that preoperative coronary artery disease (P<.0001) and hypertension (P<.01) were independent predictors of higher LVMI over time. Aortic insufficiency was none/trivial in 94% of patients and mild in 6% at 1 year. At 5 years, aortic insufficiency was none/trivial in 88% of patients, mild in 10%, and moderate in 2%. The aortic leaflets remained thin and pliable in all patients as assessed by echocardiography. Most patients (85%) were in New York Heart Association functional class I. The hemodynamic performance of the T-SPV remained unchanged during the first 5 years after implantation. The LVMI continued to decrease after the first year and tended to normalize in most patients. The aortic valve remained competent, and the leaflets did not change their thickness or show evidence of calcification.

Aortic valve replacement with stentless and stented porcine valves: a case-match study

OBJECTIVES

To assess the potential benefits of the hemodynamic superiority of stentless valves, we conducted a case-match study among patients who underwent aortic valve replacement with two types of porcine bioprostheses: the Toronto SPV and the stented Hancock II bioprosthesis.

METHODS

Preoperative clinical variables predictive of death after aortic valve replacement were determined by a stepwise logistic regression analysis in a series of 908 consecutive patients who received porcine aortic bioprostheses during a 14-year interval. Advanced age, New York Heart Association functional class IV, left ventricular ejection fraction of less than 30%, and coronary artery disease were independent predictors of death. On the basis of these four variables, 198 pairs of patients who survived aortic valve replacement with stentless and stented porcine valves were matched. The follow-up, truncated to the shortest interval for each matched pair, was 43 +/- 24 months for both groups.

RESULTS

At 8 years the actuarial survival was 91% +/- 4% for the Toronto SPV group and 69% +/- 8% for the Hancock II group (p = 0.006); the freedom from cardiac-related death was 95% +/- 4% for the Toronto SPV and 81% +/- 8% for the Hancock II (p = 0.01); the freedom from any valve-related complication was 81% +/- 5% for the Toronto SPV and 50% +/- 10% for the Hancock II (p = 0.008). A Cox proportional hazard model demonstrated a significant reduction in cardiac mortality rates and valve-related morbidity in patients who received the Toronto SPV bioprosthesis.

CONCLUSIONS

Although it is possible that confounding factors may have played a role in the clinical outcomes of this case-control study, the study suggests that aortic valve replacement with a stentless porcine valve enhances survival. This is believed to be due to the hemodynamic superiority of these valves.

Aortic valve replacement with stentless porcine aortic valves: a ten-year experience

BACKGROUND AND AIMS OF THE STUDY

It has been shown that although stentless porcine aortic valves have better hemodynamic features than stented porcine valves, their long-term durability remains unknown. This study was undertaken to examine the long-term clinical outcome of aortic valve replacement (AVR) with stentless porcine aortic valves.

METHODS

Between 1987 and 1989, custom-made stentless valves were implanted in 29 patients (mean age 58 years), and between 1991 and 1997, the Toronto SPV was implanted in 213 patients (mean age 63 years). In addition to AVR, one-third of the patients had coronary artery bypass. All patients were followed up at annual intervals and underwent Doppler echocardiography.

RESULTS

There were two operative and 11 late deaths (four cardiac, seven non-cardiac). The actuarial survival rate was 89 +/- 4% at nine years. There were two strokes and seven transient ischemic attacks; freedom from thromboembolic complications was 92 +/- 4% at nine years. Two patients developed infective endocarditis, one early and one late; freedom from prosthetic valve endocarditis was 98 +/- 1% at nine years. Freedom from primary tissue failure was 85 +/- 8% at nine years. Seven patients required repeat AVR, because of endocarditis (two) and aortic insufficiency (five); freedom from repeat AVR was 82 +/- 8% at nine years. Periodic hemodynamic assessment by echocardiography indicated that the mean systolic gradients across the valve decreased during the first year of implantation, the valve effective orifice increased, and valve competence remained stable.

CONCLUSIONS

Stentless porcine aortic valves have provided excellent clinical results. These valves may suffer degenerative changes and fail at the same rate as stented porcine aortic valves but, because of their superior hemodynamic performance, they may enhance patients' survival by allowing complete regression of left ventricular hypertrophy and restoration of normal ventricular function.

The registered nurse surgical assistant

This article provides a candid account of the evolution of two Registered Nurse Surgical Assistant positions, and their roles as members of a large open-heart team. A description of the expectation of the job, the role in surgery and the challenges and rewards are outlined.

[Histological and morphometric studies of femurs with stable hip joint replacement. An autopsy study with special reference to factors leading to late loosening]

To gain insight into the tissue reactions leading to non-infectious loosening 25 autopsy specimens of femurs with well-fixed cemented femoral components of hip prostheses were analysed histomorphologically and morphometrically. The implant duration ranged from one month to 15 years. With the exception of some focal bone-cement contacts bone and cement were separated by a fibrohistiocytic soft tissue membrane. This membrane contained wear particles predominantly of the bone cement mantle and--less abundant--of the polyethylene cups. The amount of wear particles as well as histiocytes and necroses within the membrane statistically significantly increased with advancing time in situ. The cancellous bone adjacent to the soft tissue membrane often revealed a mainly histiocytic infiltration too, accompanied by bone remodeling in this area. The histiocytic inflammatory reaction at the bone cement interface, which is mainly caused by the accumulation of wear particles is considered to be of major importance for the non infectious late loosening of cemented prostheses.

Repair of the aortic valve in patients with aortic insufficiency and aortic root aneurysm

Patients with aneurysms of the ascending aorta or aortic root frequently have aortic insufficiency despite normal aortic leaflets. The aortic valve dysfunction is caused by dilatation of the sinotubular junction, distortion or dilatation of the sinuses of Valsalva, annuloaortic ectasia, or a combination of these problems. In the case of annuloaortic ectasia, reconstruction of the aortic root is performed by reimplanting the aortic valve in a tubular Dacron graft (reimplantation). In the case of mild or no annuloaortic ectasia, reconstruction of the aortic root is performed by correcting the dilated sinotubular junction and replacement of the aortic sinuses if they are also dilated with an appropriately tailored Dacron graft (remodeling). From July 1989 to March 1994, 45 patients have had either reimplantation of the aortic valve (19 patients) or remodeling of the aortic root (26 patients). Fourteen patients had Marfan's syndrome, 11 had acute and five had chronic type A aortic dissection, and nine also had transverse arch aneurysm. There were two operative deaths, both in the remodeling group. One patient who had reimplantation needed composite replacement of the aortic valve and ascending aorta because of persistent aortic insufficiency after the repair. A young patient with Marfan's syndrome had progressive aortic valve dysfunction during a growth spurt and had aortic valve replacement 2 years after the initial operation. No other valve-related complication has occurred. The remaining 41 patients have only mild or no aortic insufficiency, and the repair remains stable from 1 to 58 months, mean 18 months. These two types of aortic valve reconstruction have provided excellent clinical results in carefully selected adult patients.

Stentless porcine bioprosthesis for aortic valve replacement

We report herein our experience with the Toronto Stentless Porcine Valve (Toronto SPV, manufactured by St. Jude Medical Inc., Minneapolis, MN, USA) for aortic valve replacement (AVR). To date 146 SPV valves have been implanted, 29 in an initial clinical trial (from October 1987 to April 1987) and 117 in the current FDA trial (September 1991 to January 1994). In the current trial the majority of patients were male (76%), aortic stenosis was the dominant lesion (73%) and 68% of the patients received a valve size 27 mm or greater. The mean age was 61.3 +/- 12.0 years. For the entire group there has been no hospital death and no patient has required a pacemaker. Perioperative complications were myocardial infarction in three patients and suspect subacute bacterial endocarditis (medically treated) in three patients. There have been two late deaths (2%), two patients have had transient ischemic attacks (2%), and one patient suffered stroke with complete neurological recovery (1%). To date there has been no case of primary valve failure. Echocardiographic assessment of the SPV valve has demonstrated excellent effective valve orifice areas with very low transvalvular gradients and 95% of the patients had either 0 or 1+ insufficiency. These results are encouraging and justify the continued use of this valve in clinical trials. Further follow-up is required to determine its durability.