Psychosocial outcomes for preschool children and families after surgery for complex congenital heart disease

The purpose of the current study was to assess the psychosocial outcomes of preschool-aged survivors (ages 3-6 years) of hypoplastic left heart syndrome (HLHS; n=13) and transposition of the great arteries (TGA; n=13). Parents completed the following measures: Pediatric Quality of Life Inventory, Impact on the Family Scale, Parenting Stress Index, Parent Behavior Checklist, and Child Behavior Checklist. Quality of life scores did not differ from those of healthy controls. Parents of children with HLHS reported more negative impact of the child's illness on the family and more parenting stress than parents of children with TGA. Parents of both groups of children were more permissive in their parenting style than parents of healthy controls. Children with HLHS had higher rates of attention and externalizing behavior problems than children with TGA. The results highlight the need for practitioners working with these children and families to ask about parental stress, family functioning, and behavioral expectations for the child in the context of routine medical/cardiac follow-up.

Interspecies transmission of Enterozytozoon bieneusi supported by observations in laboratory animals and phylogeny

Enterocytozoon bieneusi is emerging as an important cause of chronic diarrhoea in AIDS patients. Its reservoirs and transmission patterns are unknown. In this study, we have examined E. bieneusi sequences from four Rhesus macaques of different origin, which were kept at one animal facility. The sequences were identical in all animals, which suggested that infection had occurred within the facility. Full sequence agreement of E. bieneusi from macaques was found with an E. bieneusi genotype that occurs frequently in humans. To clarify, the relevance of possible inter-species transmission from man to macaque, a phylogenetic analysis was conducted including all sequences of E. bieneusi deposited in GenBank. The hitherto used system of diverse nomenclatures could be reduced to an outlier group and three main lineages, one of which could be further sub-divided into five subgroups. Based in this phylogeny, an association of parasites and host species could be observed for main lineages 2 and 3, as well as for most of the subgroups of main lineage 1. For confirmation, the phylogeny of main lineage 1 was reconstructed with an alternative method of distance estimation, yielding essentially the same parasite-host associations. Zoonotic potential of E. bieneusi is thus supported on a phylogenetic basis.

Missing the target: a comparison of buyback and fatality related guns

OBJECTIVES

To determine whether the firearms recovered in buyback programs in a large urban community are the types most closely associated with firearm fatalities in the same geographic area.

METHODS

The type, caliber, and manufacturer of 941 handguns recovered in Milwaukee County 1994-96 buyback programs were compared with 369 homicide related and 125 suicide related handguns used in Milwaukee during 1994-97.

RESULTS

Buyback handguns differed substantially from those used in homicide and suicide. One third of buyback handguns were semiautomatic pistols versus two thirds of homicide related handguns (p<0.001) and 40% of suicide related handguns (p=NS). Over 75% of buyback handguns were small caliber compared with 24% of homicide and 32% of suicide handguns (p<0.001). The top two manufacturers of buyback handguns represented 30% of these guns but only 5% of fatality related handguns (p<0.001). Companies currently out of business manufactured 15% of buyback handguns versus 7% of fatality related handguns (p<0.001).

CONCLUSIONS

Handguns recovered in buyback programs are not the types most commonly linked to firearm homicides and suicides. Although buyback programs may increase awareness of firearm violence, limited resources for firearm injury prevention may be better spent in other ways.

Characteristics of a pathogenic molecular clone of an end-stage serum-derived variant of simian immunodeficiency virus (SIV(F359))

End-stage simian immunodeficiency virus (SIV) isolates are suggested to be the most fit of the evolved virulent variants that precipitate the progression to AIDS. To determine if there were common characteristics of end-stage variants which emerge from accelerated cases of AIDS, a molecular clone was derived directly from serum following in vivo selection of a highly virulent SIV isolate obtained by serial end-stage passage in rhesus monkeys (Macaca mulatta). This dominant variant caused a marked cytopathic effect and replicated to very high levels in activated but not resting peripheral blood lymphocytes. Furthermore, although this clone infected but did not replicate to detectable levels in rhesus monocyte-derived macrophages, these cells were able to transmit infection to autologous T cells upon contact. Interestingly, although at low doses this end-stage variant did not use any of the known coreceptors except CCR5, it was able to infect and replicate in human peripheral blood mononuclear cells homozygous for the Delta 32 deletion of CCR5, suggesting the use of a novel coreceptor. It represents the first pathogenic molecular clone of SIV derived from viral RNA in serum and provides evidence that not only the genetic but also the biological characteristics acquired by highly fit late-stage disease variants may be distinct in different hosts.

Characteristics of fatal ambulance crashes in the United States: an 11-year retrospective analysis

BACKGROUND

Ambulance crashes have become an increasing source of public concern. Emergency medical services directors have little data to develop ambulance operation and risk management policies.

OBJECTIVE

To describe fatal ambulance crash characteristics, identifying those that differentiate emergency and nonemergency use crashes.

METHODS

This was a retrospective analysis of all fatal ambulance crashes on U.S. public roadways reported to the Fatality Analysis Reporting System (FARS) database from 1987 to 1997. Main outcome measures were 42 variables describing crash demographics, crash configuration, vehicle description, crash severity, and ambulance operator and vehicle occupant attributes.

RESULTS

Three hundred thirty-nine ambulance crashes caused 405 fatalities and 838 injuries. These crashes occurred more often between noon and 6 PM (39%), on improved (99%), straight (86%), dry roads (69%) during clear weather (77%), while going straight (80%), through an intersection (53%), and striking (81%) another vehicle (80%) at an angle (56%). Most crashes (202/339) and fatalities (233/405) occurred during emergency use. These crashes occurred significantly more often at intersections (p < 0.001), at an angle (p < 0.001), with another vehicle (p < 0.001). Most crashes resulted in one fatality, not in the ambulance. Thirty pedestrians and one bicyclist comprised 9% of all fatalities. In the ambulance, most serious and fatal injuries occurred in the rear (OR 2.7 vs front) and to improperly restrained occupants (OR 2.5 vs restrained). Sixteen percent of ambulance operators were cited; 41% had poor driving records.

CONCLUSIONS

Most crashes and fatalities occurred during emergency use and at intersections. The greater burden of injury fell upon persons not in the ambulance. Rear compartment occupants were more likely to be injured than those in the front. Crash and injury reduction programs should address improved intersection control, screening to identify high-risk drivers, appropriate restraint use, and design modifications to the rear compartment of the ambulance.

Independence of herpesvirus-induced T cell lymphoma from viral cyclin D homologue

Cyclin D family members are cellular protooncogenes, and their viral homologues in the Kaposi's sarcoma-associated herpesvirus (KSHV, human herpesvirus type 8 [HHV-8]) and the closely related Herpesvirus saimiri have been implicated as putative cofactors of viral transformation and pathogenesis. KSHV is regularly found in Kaposi's sarcoma and in the primary effusion B cell lymphoma and Castleman's disease associated with immunosuppression and AIDS. H. saimiri strain C488 transforms human and marmoset T cells in vitro and causes polyclonal T cell lymphoma in New World monkeys. The viral cyclins stimulate cell cycle progression of quiescent fibroblasts, and they form active cyclin-dependent kinase (CDK)6 complexes of broad substrate specificity that can resist and downregulate cellular CDK inhibitors. This study shows that the viral cyclin of H. saimiri strain C488 is not required for viral replication, T cell transformation, and pathogenicity in New World primates.

Age and gender patterns in motor vehicle crash injuries: importance of type of crash and occupant role

To evaluate the interaction of gender, age, type of crash, and occupant role in motor vehicle crash injuries leading to hospitalization, we analyzed 1997 Wisconsin hospital discharge data for patients with primary E-code diagnoses of motor vehicle injuries. The overall ratio of males to females (M/F ratio) hospitalized for motor vehicle crash injuries was 1.33 (95% confidence interval (CI): 1.26-1.41). The M/F ratio varied by type of crash and differed for passengers and drivers. For injuries sustained in collisions between vehicles, the M/F ratio was 0.96 (95% CI: 0.87-1.05); in loss of control accidents the M/F ratio was 1.95 (95% CI: 1.76-2.17). Within each type of crash, the M/F ratio for drivers was similar to that for the entire type; the M/F ratio for passengers was about half of the type total. Expressed as rates of hospitalization per 100,000 people in the general population, hospitalizations of drivers in collisions with another motor vehicle increased steeply in males, but not in females, beginning at about age 70. For drivers in loss of control crashes, male rates exceeded female rates in all age groups, with peaks in the groups 15-24 and 85-89. For passengers, injury rates from collisions with other motor vehicles were greater for females, especially in the elderly, and injury rates from loss of control crashes were similar for both genders, with peaks at 15-24 and 85-94. The higher fatality of men in loss of control motor vehicle crashes, compared to women, suggests an important area for further investigation.

Safety and immunogenicity of ALVAC wild-type human p53 (vCP207) by the intravenous route in rhesus macaques

p53 is over-expressed in approximately 50% of human cancers, and transfer of cytotoxic T lymphocytes (CTL) against wild-type p53 protects mice against p53-over-expressing tumors, suggesting that p53 might be an attractive target for immunotherapy. Immunization of mice with a recombinant canarypox virus, ALVAC, expressing human wild-type p53 (vCP207) prevented growth of p53-over-expressing tumors. Since intravenous administration induced better immune responses in mice than other routes, we have proposed to use this route in cancer patients. However, because this vector has never been administered intravenously to humans, and because of the possibility of inducing auto-immunity to a self-antigen, we felt it was necessary to first evaluate safety in rhesus macaques. We found that three intravenous administrations of vCP207 at proportional doses up to 10x those proposed for humans produced no abnormalities in hematologic or clinical chemistry parameters. Serologic markers of autoimmunity and inflammation were unaffected, despite the >95% amino acid identity between human and rhesus p53. Pathological examination of numerous tissues yielded findings comparable to those in animals given placebo. Some animals showed anti-p53 antibody responses following vaccination, indicating that tolerance could be broken to some extent. However, with the exception of one animal with a possible delayed type hypersensitivity reaction to p53 protein, we did not see evidence for a cell-mediated response. The safety profile in monkeys with ALVAC-p53 provides encouragement for using such live, modified vectors via the intravenous route for human immunotherapy.

Herpesvirus saimiri vFLIP provides an antiapoptotic function but is not essential for viral replication, transformation, or pathogenicity

Apoptosis of infected cells is an important host defense mechanism, and many viruses have exploited antiapoptotic proteins that interfere with crucial cellular pathways. Viral FLICE inhibitory proteins (vFLIPs) are encoded by rhadinoviruses like herpesvirus saimiri, the related Kaposi's sarcoma-associated herpesvirus-human herpesvirus 8 (KSHV/HHV8), and the poxvirus responsible for molluscum contagiosum. The vFLIPs can block the interaction of the death receptor-adapter complex with the cellular effector FLICE (caspase-8), and this prevents the initiation of the downstream caspase cascade. KSHV/HHV8 vFLIP overexpression can confer resistance to T-cell-mediated apoptosis and acts as a tumor progression factor in a murine B-cell lymphoma model. To analyze the function of herpesvirus vFLIPs in the genetic background of the virus and in a model for viral pathogenesis, we deleted the vFLIP gene (open reading frame 71) from the genome of herpesvirus saimiri strain C488. The viral deletion mutant was viable and replicated like the wild-type virus. An antiapoptotic effect could be attributed to the vFLIP gene, but we also show that the vFLIP gene of herpesvirus saimiri is dispensable for viral transformation of T cells in vitro and for pathogenicity in cottontop tamarins in vivo.

Successful suppression of the early rejection of pig islets in monkeys

Primary nonfunction (PNF) is seen very frequently after xenogeneic transplantation of islets of Langerhans. In a pig-to-rat model we recently observed that no PNF occurs when the islets are kept in culture at 37 degrees C for 1-2 weeks prior to transplantation. In order to investigate the rejection mechanisms in a preclinical model, we transplanted cultured porcine islets under the capsule of both kidneys in four cynomolgous monkeys. Islets were isolated from adult sows by means of digestion with Liberase in University of Wisconsin solution (UWS). The digest was purified by a density gradient of OptiPrep in UWS. Highly purified (>95%) islets were cultured 1-2 weeks in RPMI. All monkeys showed significant titers of preformed anti-pig antibodies. The immunosuppression of the monkeys consisted of cyclophosphamide (Cy) (2 days), cyclosporin A (CsA), and prednisolone. Anticipating a fast rejection we carried out nephrectomies at different time points within 2 weeks after transplantation. Following unilateral nephrectomy, well-preserved islets with no signs of rejection were observed between 3 and 7 days posttransplant. Later, between days 11 and 15 posttransplant, histology in the first three animals demonstrated no islets. In the fourth monkey histology on day 11 showed islets with excellent morphology and some small focal infiltrates. The highest CsA blood levels (around 1000 ng/ml) were found in animals with the best graft survival. We conclude that cultured porcine islets can be grafted without hyperacute rejection in monkeys with preformed anti-pig antibodies. In the presence of high levels of CsA only marginal signs of a cellular immune response were observed 11 days after transplantation.

The added diagnostic value of automated QT-dispersion measurements and automated ST-segment deviations in the electrocardiographic diagnosis of acute cardiac ischemia

The purpose of this study was to determine the added value of automated QT dispersion and ST-segment measurements to physician interpretation of 12-lead electrocardiograms (ECGs) in patients with chest pain. To date, poor reproducibility of manual measurements and lack of shown added value have limited the clinical use of QT dispersion. Twelve-lead ECGs (n = 1,161) from the Milwaukee Prehospital Chest Pain Database were independently classified by 2 physicians into 3 groups (acute myocardial infarction (AMI), acute cardiac ischemia (ACI), or nonischemic), and their consensus was obtained. QT-end and QT-peak dispersions were measured by a computerized system. The computer also identified ST-segment deviations. Sensitivity, specificity, and positive predictive values (PPVs) and negative predictive values (NPV) for AMI and ACI were evaluated independently and in combinations. For AMI, physicians' consensus classification was remarkably good (sensitivity, 48%, specificity, 99%). Independent classification by QT-end and QT-peak dispersions or ST deviations was not superior to the physicians' consensus. Optimal classification occurred by combining automated QT-end dispersion and ST deviations with physicians' consensus. This combination increased sensitivity for the diagnoses of AMI by 35% (65% vs 48%, P < .001) and ACI by 55% (62% vs 40%, P < .001) compared with physicians' consensus, while maintaining comparable specificity. This study supports a potential clinical role for automated QT dispersion when combined with other diagnostic methods for detecting AMI and ACI.

Microsporidia and Candida spores: their discrimination by Calcofluor, trichrome-blue and methylene-blue combination staining

Faeces of immunocompromised patients are often contaminated with the chitin-containing spores of microsporidia and Candida, which exclude the use of the chitin-specific fluorescent brightener Calcofluor white M2R for the identification of microsporidian spores. We developed a combination staining of Calcofluor white M2R with modified trichrome-blue staining and subsequent methylene-blue incubation which permits discrimination between these two types of spores. As a basis for diagnosis, a difference in the fluorescence pattern (365-440 nm) is combined with a difference in the light microscopic staining pattern. Under fluorescence conditions microsporidia spores have a spotted, brilliant white Calcofluor fluorescence and can easily be identified, while Candida spores show a reddish purple colour. Under the light microscope microsporidian spores show a light red colour with nonstained vacuole spots or strips in contrast to the yeast spores with their red-brown colour. This combination technique offers a highly specific means for the diagnosis of microsporidia spores in faeces.

Antiretroviral therapy during primary immunodeficiency virus infection can induce persistent suppression of virus load and protection from heterologous challenge in rhesus macaques

A limited period of chemotherapy during primary immunodeficiency virus infection might provide a long-term clinical benefit even if treatment is initiated at a time point when virus is already detectable in plasma. To evaluate this strategy, we infected rhesus macaques with the pathogenic simian/human immunodeficiency virus RT-SHIV and treated them with the antiretroviral drug (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA) for 8 weeks starting 7 or 14 days postinfection. PMPA treatment suppressed viral replication efficiently in all of the monkeys. After chemotherapy ended, virus replication rebounded and viral RNA in plasma reached levels comparable to that of the controls in four of the six monkeys. However, in the other two animals, virus loads peaked only moderately after withdrawal of the drug and then declined to low or even undetectable levels. These low levels of viremia remained stable for at least 31 weeks after cessation of therapy. At this time point, these two monkeys were challenged with SIV(8980) to evaluate whether the host responses which were able to keep RT-SHIV replication under control were also sufficient to protect against infection with a highly pathogenic heterologous virus. Both monkeys proved to be protected against the heterologous virus. In one of the two animals, low levels of SIV(8980) replication were detected. Thus, by chemotherapy during the acute phase of pathogenic virus replication, we could achieve not only persistent virus load suppression in two out of six monkeys but also protection from subsequent heterologous challenge. By this chemotherapeutic attenuation, the replication kinetics of attenuated viruses could be mimicked and a vaccination effect similar to that induced by live attenuated simian immunodeficiency virus vaccines was achieved.

Morphologic and immunophenotypic characteristics of malignant lymphomas in SIV-infected rhesus macaques

Eight cases of extranodal non-Hodgkin's lymphoma in simian immunodeficiency virus (SIV)-infected rhesus macaques, aged 4-9 years, were phenotypically and immunologically characterized, using the updated Kiel classification, in order to determine both the differences and the similarities between these types of lymphoma in immunodeficient rhesus macaques (Macaca mulatta) and man. The high-grade malignant tumors were of B-cell origin, with a predilection for extranodal growth in viscera and periorbital tissues. Immunophenotypical characterization showed that the monkey lymphomas were similar in many aspects to human immunodeficiency virus-associated lymphomas. The number of Ki67 positive cells varied from case to case and ranged from 50 to 90%. A serological screening for the simian equivalent of the Epstein-Barr virus (sEBV) by immunofluorescence assay revealed a prevalence of 92% of the sEBV antibodies in our cohort. The presence of Ebstein-Barr virus nuclear antigen (EBNA-2) could be demonstrated by immunohistochemistry in four out of eight cases. In situ hybridization revealed the presence of small EBV-encoded RNAs (EBER-1, EBER-2) in six of the eight cases. Further studies should define the precise role of herpesvirus infection for lymphomagenesis in SIV-induced immunodeficiency.

Hospitalizations for vehicle associated injuries in Wisconsin

Computerized data from the Wisconsin Office of Health Care Information (OHCI) was utilized to evaluate the epidemiology of vehicle associated injuries treated in acute care Wisconsin hospitals in 1997. There were 6043 vehicle associated injuries which required hospitalization in Wisconsin in 1997, a rate of 141 per 100,000 males and 91 per 100,000 females. Seventy-eight percent of these were motor vehicle traffic related (8% of which involved collisions with pedestrians), 9% were motor vehicle non-traffic related and 6% were pedal cycle related. This study demonstrates how the risk of these various types of vehicle related injuries varied with age, gender, and county of residence, and describes the distribution of morbidity associated with each type. The information described in this paper may be useful in developing hypotheses regarding the causes of vehicle related injuries in Wisconsin, and ultimately lead to the development of interventions which will decrease morbidity, mortality, and costs due to vehicle related injuries.

Prognostic factors for persons with idiopathic chronic fatigue

BACKGROUND

The simultaneous examination of a large number of patient characteristics in a prospective study of patients with chronic fatigue.

OBJECTIVE

To compare the relative importance of these characteristics as prognostic factors.

METHODS

The data analyzed were from 199 subjects in a registry of persons who were aged 18 years or older and had idiopathic fatigue for at least 6 months. All subjects completed an extensive baseline questionnaire that provided information about fatigue, demographic characteristics, medical conditions, lifestyle, sleeping habits, psychological characteristics, and the presence of criteria for chronic fatigue syndrome. Changes in fatigue severity from baseline to 2-year follow-up were tested for an association with risk factors at baseline and with changes in symptoms other than fatigue during the follow-up period.

RESULTS

The following characteristics at baseline significantly and independently predicted greater fatigue improvement: less unclear thinking, fewer somatoform symptoms not used to define chronic fatigue syndrome, infrequent awakening, fewer hours sleeping, and being married. Of 29 subjects who at baseline reported no somatoform symptoms unrelated to chronic fatigue syndrome and who thought clearly most of the time, 8 substantially improved, compared with 1 of 29 subjects who had more than 2 somatoform symptoms and never thought clearly (P = .01). Improvements in the following symptoms were significantly and independently associated with improvements in fatigue: unclear thinking, depression, muscle aches, and trouble falling asleep.

CONCLUSIONS

This study identified characteristics of subjects that seem to be of prognostic importance for idiopathic chronic fatigue. Symptoms that change concomitantly with changes in fatigue may be intrinsically linked to fatigue.

Prevention of renal allograft rejection in primates by blocking the B7/CD28 pathway

BACKGROUND

There is accumulating evidence that blockade of the costimulatory pathways offers a valid approach for immune suppression after solid organ transplantation. In this study, the efficacy of anti-CD80 and anti-CD86 monoclonal antibodies (mAbs) in combination with cyclosporine (CsA) to prevent renal allograft rejection was tested in non-human primates.

METHODS

Rhesus monkeys were transplanted with a partly major histocompatibility complex-matched kidney on day 0. Anti-CD80 and anti-CD86 mAbs were administered intravenously daily for 14 days starting at day - 1. CsA was given intramuscularly for 35 days starting just after transplantation. The kidney function was monitored by determining serum creatinine levels.

RESULTS

The combination of anti-CD80 and anti-CD86 mAbs completely abrogated the mixed lymphocyte reaction. Untreated rhesus monkeys rejected the kidney allograft in 5-7 days. Treatment with anti-CD80 plus anti-CD86 mAbs resulted in a significantly prolonged graft survival of 28+ 7 days (P=0.025). There were no clinical signs of side effects or rejection during treatment. Kidney graft rejection started after the antibody therapy was stopped. The anti-mouse antibody response was delayed from day 10 to 30 after the first injection. No difference in graft survival was observed between animals treated with CsA alone or in combination with anti-CD80 and anti-CD86 mAbs. However, treatment with anti-CD80 and anti-CD86 mAbs reduced development of vascular rejection.

CONCLUSIONS

In combination, anti-CD80 and antiCD86 mAbs abrogate T-cell proliferation in vitro, delay the anti-mouse antibody response in vivo, and prevent graft rejection and development of graft vascular disease in a preclinical vascularized transplant model in non-human primates.

An anti-HIV strategy combining chemotherapy and therapeutic vaccination

Combination chemotherapy using potent anti-retroviral agents has led to significant advances in the clinical management of human immunodeficiency virus (HIV) disease. However, the emergence of multiple drug-resistant mutants, the high need for compliance to adhere to demanding drug-dosing schemes, and the remaining toxic side-effects of drugs make the perspective of life-long treatment unattractive and possibly unrealistic. Therefore, means must be sought to shorten the time span during which treatment is necessary. Such means could be to stimulate an efficient immune response during the period of low virus load and restored CD4 + cell levels, which might be capable of keeping the virus under long-lasting control after treatment is stopped. Here we tested this concept of combined chemotherapy/ therapeutic vaccination in a non-human primate model. Rhesus macaques chronically infected with the chimeric simian/human immunodeficiency virus (SHIV) containing the HIV type 1 (HIV-1) HXBc2 gene for reverse transcriptase (RT) in the genomic background of simian immunodeficiency virus (SIV)(mac239) (RT-SHIV) were treated with (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA), a potent anti-HIV drug. When virus load had decreased significantly, we immunized with SIV genes env, gag/pol, rev, tat, and nef inserted in two different expression vector systems. Four weeks after the second immunization, drug treatment was stopped. Animals were monitored to determine if virus load stayed low or if it increased again to the original levels and if CD4+ T-cell levels remained stable. Humoral and cellular immune responses were also measured. This combined chemotherapy/ therapeutic vaccination regimen induced a significant reduction in the steady-state level of viremia in one out of two chronically infected rhesus macaques. Chemotherapeutic treatment alone did not achieve reduction of viremia in two chronically infected animals. The nature of the immune responses assumed to have been induced by vaccination in one out of the two monkeys remains to be elucidated.

A case of intestinal Mycobacterium simiae infection in an SIV-infected immunosuppressed rhesus monkey

Although Mycobacterium simiae was identified and classified more than three decades ago, only a few cases are mentioned in the current literature. After experimental simian immunodeficiency virus infection, a 9-year-old female rhesus monkey (Macaca mulatta) developed progressive immunosuppression and gastrointestinal disease very similar to the clinical and pathomorphologic features of Johne's disease, which is caused by M. paratuberculosis. Acid-fast-positive bacteria reacted immunohistochemically with antibodies against M. paratuberculosis and M. bovis but were not useful for differentiation because of a high degree of cross-reactivity. In contrast to immunohistochemistry and histopathology, biochemical methods and cycle sequencing analysis of the 16S ribosomal RNA identified M. simiae as the disease-causing pathogen. This case demonstrates the importance of molecular biological methods for the diagnosis of M. simiae infection in monkeys.

The acidic region and conserved putative protein kinase C phosphorylation site in Nef are important for SIV replication in rhesus macaques

Variants of the pathogenic SIVmac239 clone with changes in Nef were analyzed to assess the functional relevance of two highly conserved regions in Nef in vitro and in vivo. Changes in a region with an acidic charge (Aci-Nef), or a potential protein kinase C phosphorylation site (PKC-Nef), impaired the ability of Nef to down-regulate CD4 and MHC class I surface expression and to alter CD3-initiated signal transduction in Jurkat T cells. The Aci-Nef, but not the PKC-Nef, associated with the previously described p65 phosphoprotein. SIV containing Aci-Nef, but not SIV containing PKC-Nef, showed reduced infectivity and replication in cell culture systems. One of two rhesus macaques infected with the PKC-Nef mutant virus showed rapid reversion and progressed to disease. In the second animal no reversions and nonprogressive infection was observed. In one of two macaques infected with the Aci-Nef variant, the mutations were stable during the first 40 weeks after infection. Thereafter, variants evolved in which up to six of the eight mutated positions in Nef were reverted and functional activity in vitro was partially restored. These changes occurred concomitantly with increasing viral load and disease progression. The second animal infected with the Aci-Nef variant showed no reversions and remained asymptomatic. Our study suggests that the acidic region and conserved PKC phosphorylation site in Nef are important for SIV replication in rhesus macaques and for several in vitro Nef functions. An almost wild-type activity in in vitro infectivity and replication assays seems insufficient to confer a full nef-positive phenotype in vivo.

Pre-transplant identification of risk factors that adversely affect length of stay and charges for renal transplantation

BACKGROUND

In the current era of renal transplantation, increasing attention is being focused on resource utilization. The purpose of this study was to identify demographic, medical and immunologic risk factors that are associated with changes in length of stay (LOS) and charges for renal transplantation.

METHOD

The study was a retrospective analysis of 311 consecutive renal transplants performed at a single institution. Univariate and multivariate analyses were used to examine relationships between risk factors, LOS, charges and post-operative complications.

RESULTS

The following pre-transplant variables were found to be independently significant in predicting increased LOS and/or charges: African-American race, obesity for women, chronic obstructive pulmonary disease (COPD), presence of cardiac disease or previous stroke, pre-transplant dialysis time > or = 1 yr, a 10% increase in panel reactive antibody (PRA), cadaver donor and retransplantation. The analyses were performed with and without adjustment for key outcome variables such as delayed graft function (DGF) and use of induction antibody therapy. Increased LOS or charges for specific risk factors could be attributed to increased complication rates, including delayed graft function seen with various co-morbidities, or increased immunologic risk and more frequent use of induction antibody therapy.

CONCLUSION

Analysis of linked financial and clinical databases can reveal demographic, medical and immunologic risk factors that correlate with LOS, charges and complications for renal transplantation. Efforts to establish quantitative relationships for various risk factors relative to resource utilization will become important in managed care and/or capitated healthcare delivery systems.

Immunohistochemical studies of productive rhesus cytomegalovirus infection in rhesus monkeys (Macaca mulatta) infected with simian immunodeficiency virus

In humans infected with the human immunodeficiency virus (HIV), clinical disease due to human cytomegalovirus (HCMV) infection is one of the AIDS-defining diseases; HCMV is the most common opportunistic infection found postmortem. Histologically, the typical lesions are characterized by "owl's eye cells." In rhesus monkeys infected with simian immunodeficiency virus (SIV), comparable lesions are caused by an infection with the rhesus CMV (RhCMV). The aim of this study was to investigate the incidence of productive and latent RhCMV infection in monkeys infected with SIV macaques (SIVmac). Eleven SIVmac-infected rhesus monkeys, which were euthanatized after developing AIDS-like disease, and 11 clinically healthy and uninfected animals comprised the study. The monkeys were screened serologically for RhCMV by western-blot analysis. Immunohistochemistry was performed by an indirect immunoperoxidase technique with a polyclonal rabbit RhCMV-antiserum. Lesions characteristic of RhCMV-associated diseases were detected histologically. All animals were latently RhCMV-infected. Seven of eleven (63.6%) SIV-infected macaques were productively RhCMV infected according to immunohistochemistry. RhCMV antigen was identified in the gastrointestinal tract, the hepatobiliary system, the lungs, and the testicles. Two of these seven animals showed characteristic inflammatory lesions associated with productive infection. Consequently, the CMV prevalence in SIVmac-infected rhesus monkeys and human AIDS patients is comparable.

Prestige of training programs and experience of bypass surgeons as factors in adjusted patient mortality rates

OBJECTIVES

The relation of physician performance to physician training and experience is not well understood. The aim of this study was to examine whether indicators of physician background and experience were associated with an objective measure of physician performance.

METHODS

Physician background information obtained from the Directory of Board-Certified Medical Specialists was linked to physician risk-adjusted mortality rates obtained from three statewide data bases of coronary artery bypass surgeons. Subjects were 275 surgeons who performed CABG surgery on 83,547 patients during the years 1989 to 1992. Surgical performance was measured by the mortality ratio (MR), the ratio of the observed to the predicted patient mortality rate as determined by detailed clinical information. Training institutions and physicians were characterized as prestigious if they were listed as outstanding in published articles.

RESULTS

Surgical performance was not associated with graduation from an American medical school; attendance at a prestigious medical school, residency, or fellowship program; or an academic appointment. Mortality ratios decreased with increased volume and increased with years of experience, age, and academic rank. Surgeons were more likely to be considered a "best doctor" if they had more years experience and trained at a prestigious residency or fellowship program.

CONCLUSIONS

Training at a prestigious institution was associated with identification as a "best" doctor but not with lower mortality ratios.

Charges for childhood asthma by hospital characteristics

BACKGROUND

The ownership, location, and teaching status of hospitals affect their missions, policies, finances, and operations.

OBJECTIVE

This study assesses the relationship of hospital ownership, location, and teaching status with charges and length of stay for children with asthma, the most common reason for pediatric admission after birth.

METHODS

All 28 545 complete records of patients </=18 years of age with the principal diagnosis asthma in 1994 were extracted from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample, providing a stratified sample of 735 nonfederal, acute-care hospitals in 17 states. Multiple regression analysis on log transformed data was used to calculate mean total charges and average length of stay (ALOS) after adjusting for illness severity and mortality risk (four All Patient Refined-Diagnosis Related Group classes based on secondary diagnoses and procedures); payer (Medicaid, private, uninsured, other); patient age, sex, income (four categories based on ZIP code of residence); state; bed size (three categories varying by location); hospital ownership; location; teaching status; and admission month.

RESULTS

Asthma severity did not differ significantly by hospital location or teaching status. Nonprofit hospitals treated a slightly higher proportion of children with major or extreme severity asthma than either public or for-profit hospitals. Urban teaching hospitals treated more children with asthma who lived in low-income neighborhoods, were uninsured, or received Medicaid coverage than urban nonteaching hospitals. For-profit hospitals admitted fewer children with asthma from low-income areas than did public hospitals. The ALOS was 2.5 days and did not differ significantly by hospital ownership, location, or teaching status. However, the mean total charges, after adjusting for all other significant covariates, was higher at for-profit ($4203) than at nonprofit ($3640) or public hospitals ($3620). Average charges also were higher at urban teaching ($4230) and lower at rural institutions ($2910) compared with urban nonteaching hospitals ($3424).

CONCLUSIONS

Despite similar ALOS, mean charges for childhood asthma varied significantly by hospital ownership, location, and teaching status. Implications. Additional clinical and outpatient data are needed to study variations in quality of care by hospital characteristics. With the proliferation of investor-owned hospitals, both the reasons for and the impact of higher average charges at for-profit institutions require additional investigation. With the expanding needs of the medically underserved, socially just policies are required for financing hospitals that care for a disproportionate share of economically disadvantaged children.

Complete withdrawal of immunosuppression in kidney allograft recipients: a prospective study in rhesus monkeys

BACKGROUND

We previously reported the successful withdrawal of immunosuppression in kidney-allografted rhesus monkeys. Recipients had received pretransplant blood transfusions and cyclosporine (CsA) immunosuppression for 6 to 12 months. One animal is still alive at more than 15 years after transplantation. Our hypothesis was that the sharing of a single DR antigen between blood donor and recipient, and the sharing of the same DR antigen with the kidney donor, may be beneficial to allograft survival. We now report on the results from a prospective study.

METHODS

The animals received three pretransplant blood transfusions from a single donor sharing one DR antigen with the recipient. Subsequently, a life-supporting kidney from a donor sharing the same DR antigen was transplanted. CsA was given for at least 6 months after transplantation.

RESULTS

Two animals rejected their graft at 5-8 weeks after cessation of CsA treatment. One animal is still alive at 700 days after transplantation. This animal showed MLR nonreactivity to its kidney donor, similar to the animal at more than 15 years after transplantation.

CONCLUSION

These results demonstrate that withdrawal of immunosuppression may be a realistic option in kidney graft patients under careful immunological monitoring of donor-specific immunity.

The interleukin-17 gene of herpesvirus saimiri

In comparison to wild-type herpesvirus saimiri, viral interleukin-17 gene knockout mutants have unaltered behavior regarding viral replication, T-cell transformation in vitro, and pathogenicity in cottontop tamarins. Thus, this gene is not required for T-cell lymphoma induction but may contribute to apathogenic viral persistence in the natural host, the squirrel monkey.

Platynosomum fastosum in ex-captive orangutans from Indonesia

The liver fluke Platynosomum fastosum was identified upon necropsy of three ex-captive orangutans (Pongo pygmaeus) which had been part of a rehabilitation program for reintroduction to the wild. This trematode has not been reported in orangutans previously and is commonly found in cats in Southeast Asia. Cross infection from cats via intermediate hosts, to orangutans kept in captivity as pets, could explain their presence in the latter. Although P. fastosum caused intrahepatic and bile duct damage, death of the hosts could not be attributed solely to the presence of the liver fluke infection.

Hospitalization costs associated with homelessness in New York City

BACKGROUND

Homelessness is believed to be a cause of health problems and high medical costs, but data supporting this association have been difficult to obtain. We compared lengths of stay and reasons for hospital admission among homeless and other low-income persons in New York City to estimate the hospitalization costs associated with homelessness.

METHODS

We obtained hospital-discharge data on 18,864 admissions of homeless adults to New York City's public general hospitals (excluding admissions for childbirth) and 383,986 nonmaternity admissions of other low-income adults to all general hospitals in New York City during 1992 and 1993. The differences in length of stay were adjusted for diagnosis-related group, principal diagnosis, selected coexisting illnesses, and demographic characteristics.

RESULTS

Of the admissions of homeless people, 51.5 percent were for treatment of substance abuse or mental illness, as compared with 22.8 percent for the other low-income patients, and another 19.7 percent of the admissions of homeless people were for trauma, respiratory disorders, skin disorders, and infectious diseases (excluding the acquired immunodeficiency syndrome [AIDS]), many of which are potentially preventable medical conditions. For the homeless, 80.6 percent of the admissions involved either a principal or a secondary diagnosis of substance abuse or mental illness -- roughly twice the rates for the other patients. The homeless patients stayed 4.1 days, or 36 percent, longer per admission on average than the other patients, even after adjustments were made for differences in the rates of substance abuse and mental illness and other clinical and demographic characteristics. The costs of the additional days per discharge averaged $4,094 for psychiatric patients, $3,370 for patients with AIDS, and $2,414 for all types of patients.

CONCLUSIONS

Homelessness is associated with substantial excess costs per hospital stay in New York City. Decisions to fund housing and supportive services for the homeless should take into account the potential of these services to reduce the high costs of hospitalization in this population.

T-cell lymphoma caused by herpesvirus saimiri C488 independently of ie14/vsag, a viral gene with superantigen homology

The immediate-early gene ie14/vsag of herpesvirus saimiri has homology with murine superantigens. We compared the pathogenesis of infection with either ie14/vsag deletion mutants or wild-type virus C488 in cottontop tamarin monkeys (Saguinus oedipus). Two weeks after infection, all animals developed acute T-cell lymphomas independently of the presence of the viral ie14/vsag gene.

Cytokine gene transcription in simian immunodeficiency virus and human immunodeficiency virus-associated non-Hodgkin lymphomas

Infection of rhesus monkeys with SIV leads to AIDS-like symptoms. Similar to human AIDS patients, some monkeys develop B cell non-Hodgkin lymphoma (NHL). We determined transcription of cytokine genes regulating the activation of B and T cells, which play a role in intratumoral immune surveillance. Therefore, we compared the transcription of the cytokine genes encoding IL-2, IL-4, IL-6, IL-10, IFN-gamma, TNF-alpha, and TGF-beta1, and the Epstein-Barr virus-encoded BCRF 1 gene, in cells from five monkey and two human tumor specimens. The immune-suppressive IL-10 and TGF-beta1 genes were predominantly transcribed in all tumor specimens analyzed. Cytokine gene transcription patterns appeared to be similar in human and animal tumor cells. The transcription patterns corresponded to their histological classification as diffuse large-cell lymphoma according to the REAL classification and as immunoblastic or centroblastic tumors according to the Kiel classification. The determination of cytokine gene transcription pattern in the NHL may improve our understanding of pathogenesis and immune surveillance in this heterogeneous group of tumors. Our data show that SIV-associated NHLs of rhesus monkeys are comparable to human HIV-1-associated EBV-positive non-Hodgkin lymphoma.

Intestinal manifestations of experimental SIV-infection in rhesus monkeys (Macaca mulatta): a histological and ultrastructural study

Intestinal lesions were studied in 32 rhesus monkeys experimentally infected with different strains of simian immunodeficiency virus SIVmac (251/32H, 251/32H-SPL and 251/MPBL) by light microscopy, transmission and scanning electron microscopy. A spectrum of primary and secondary manifestations of SIV-infection were detected. Primary changes included 'SIV-enteropathy' in 12 monkeys and virus-induced syncytial giant cell formation (GCF) of the intestine in two animals. A primary virus-induced enteropathy occurred both as only histologically visible 'SIV-enteropathy' and as 'AIDS-enteropathy' accompanied by clinical signs of enteritis. Secondary opportunistic infections (Balantidium coli, Cryptosporidium, Trichuris, Trichomonas, Spironucleus, Mycobacteria and Cytomegalovirus) were identified in 27 animals and three monkeys developed malignant lymphomas involving the intestinal tract. Compared to intestinal lesions in HIV-infected patients, differences were found concerning the incidence of GCF and the range of opportunistic infections, with cryptosporidium, cytomegalovirus and mycobacteria occurring in both SIV-infected macaques and AIDS patients. The present observations revealed that SIV-infected rhesus monkeys provide an excellent model both for studies on the pathogenesis of HIV-enteropathy and opportunistic infections and for the development of therapies against cryptosporidial, cytomegalovirus and mycobacteria infection. Comparison of three SIV-strains revealed differences in primary and secondary lesions observed: SIVmac251/MPBL was correlated with severe primary SIV-induced pathologic changes and SIVmac251-SPL-infected animals showed a higher incidence of malignant lymphomas.

Are the best coronary artery bypass surgeons identified by physician surveys?

OBJECTIVES

This study assessed the validity of surveys for identifying the best coronary artery bypass surgeons.

METHODS

Data on physicians who performed coronary artery bypass surgery were available from New York, Pennsylvania, and Wisconsin. Data on physicians' reputation were obtained from one national and five city surveys. The measure of surgical performance was the mortality ratio (MR), that is, the ratio of the observed to the predicted patient mortality rate.

RESULTS

Mortality ratios were very similar for the 10,722 patients treated by the 31 surgeons defined as "best" doctors in the surveys (MR = 98) and for the 74,854 patients treated by 243 other surgeons who had more than a minimal number of cases (MR = .96). The mortality ratio was 1.34 for the patients treated by surgeons with the lowest volumes and .87 for the surgeons who performed more than 400 coronary artery bypass surgeries in 3 years.

CONCLUSIONS

These results suggest that the quality of a coronary artery bypass surgeon may be more closely associated with patient volume than with the surgeon's reputation among peers.

The relationship of the value of outcome comparisons to the number of patients per provider

PURPOSE

Monte Carlo methods were used to assess how the value of outcome comparisons depends on the number of patients per provider.

METHODS

We simulated two patient data sets that have been used for well-known studies of outcome comparisons: mortality rates for coronary artery bypass surgeons from New York and Pennsylvania, and 30-day hospital mortality rates of Medicare patient from a national data set. In the simulated data sets, each surgeon or hospital provider was assigned a true or underlying probability of mortality.

RESULTS

For the simulated CABG surgery data set, the underlying probability of mortality explained 30% of the variation in the observed mortality rate when there were 100 patients per physician, and 63% when there were 400 patients. The positive predictive value of using an observed mortality rate in the bottom 10% to identify a surgeon whose underlying probability of mortality was in the bottom 10% was 31% for 100 patients and 59% for 400 patients. The relationship between underlying and observed rates was weaker in the simulated Medicare data set with the same number of patients per provider. For a given data set, the amount of random variation in the observed rates of adverse outcomes among providers can be estimated with a simple equation.

CONCLUSION

The results show that the assessment of provider outcomes may be greatly affected by random variation. An indication of the amount of random variation in a given data set can be obtained from the examples in this study and an equation for estimating random variation.

Association of simian immunodeficiency virus Nef with cellular serine/threonine kinases is dispensable for the development of AIDS in rhesus macaques

The nef gene of simian immunodeficiency virus (SIV) is essential for high viral load and induction of AIDS in rhesus monkeys. A mutant form of the SIVmac239 Nef, which contains changes in a putative SH3-binding domain (amino acids 104 and 107 have been changed from PxxP to AxxA), does not associate with cellular serine/threonine kinases, but is fully active in CD4 downregulation and associates with the cellular tyrosine kinase Src. Infection of two rhesus macaques with SIVmac239 containing the mutant AxxA-Nef caused AIDS and rapid death in both animals. No reversions were observed in the majority of nef sequences analyzed from different time points during infection and from lymphatic tissues at the time of death. Our findings indicate that the putative SH3-ligand domain in SIVmac Nef and the association with cellular serine/threonine kinases are not important for efficient replication and pathogenicity of SIVmac in rhesus macaques.

Live attenuated SIV vaccines are not effective in a postexposure vaccination model

Live attenuated simian immunodeficiency virus (SIV) vaccines, like nef deletion mutants, have been the most effective vaccines tested in the SIV/macaque model so far. The efficacy of live attenuated SIV vaccines in therapeutic vaccination and postexposure prophylaxis has not been determined. Inoculation of macaques with a pathogenic challenge virus and an attenuated SIV vaccine at the same time mimics postexposure vaccination, whereby vaccination with the attenuated virus is performed as rapidly as possible after exposure to pathogenic SIV. In the study presented here, four rhesus macaques were coinfected with pathogenic SIV and a nearly 3000-fold excess of a nef deletion mutant of SIV. Four macaques received pathogenic SIV and an approximately 200-fold excess of a nef deletion mutant expressing interleukin 2 (IL-2). The IL-2-expressing SIV had been previously constructed to enhance the immunogenicity of live attenuated SIV vaccines. All coinfected macaques had a high viral load, and some of them developed AIDS-like symptoms and pathological alterations rapidly. In the presence of pathogenic SIV, both live attenuated SIV vaccines did not protect from disease in this postexposure vaccination model.

Rapid development of vaccine protection in macaques by live-attenuated simian immunodeficiency virus

Convincing data on experimental vaccines against AIDS have been obtained in the simian immunodeficiency virus (SIV) macaque model by preinfection with a virus attenuated by a nef deletion. To investigate the efficacy of a nef deletion mutant of SIVmac32H called pC8 as a live-attenuated vaccine after shorter preinfection periods and to learn more about the nature of the immune protection induced, eight rhesus monkeys were infected intravenously with the pC8 virus. All monkeys became persistently infected, exhibiting low cell-associated viral loads, but strong cellular and, in terms of binding antibodies, strong humoral antiviral responses. Two of eight pC8-infected monkeys developed an immunodeficiency and were not challenged. Sequence analysis of their nef revealed complete replenishment of the deletion. The other six monkeys, two preinfected for 42 weeks and four for 22 weeks, were challenged with pathogenic spleen-derived SIV. Complete protection was achieved in four vaccinees. Virus was consistently detected in two vaccinees from the 22-week-group challenge, however, they remained clinically healthy over a prolonged period. Protection from challenge virus infection or a delayed disease development seemed to be associated with a sustained SIV-specific T helper cell response after challenge. Thus, a sterilizing immunity against superinfection with pathogenic SIV can be induced even after a relatively short waiting period of 22 weeks. Nevertheless, such a vaccine raises severe safety concerns because of its potential to revert to virulence.

Morphological characteristics of the ileal Peyer's patches in the rhesus macaque: a histological and ultrastructural study

Ileal Peyer's patches of rhesus macaques were investigated by light and electron microscopy (scanning-electron microscopy, transmission-electron microscopy). The results were compared with findings in other species. Differences were found concerning the shape of the dome area, the composition of the dome epithelium and the apical membrane of M cells: in the rhesus monkey, hemispherical domes bulge into the intestinal lumen. The dome epithelium is composed of three populations of gut epithelial cells; absorptive enterocytes as the predominant cell type; goblet cells; and M cells ("microfold bearing' or "membraneous' gut epithelial cells). The apical membrane of M cells forms irregular protrusions.

Test of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) for prehospital use

STUDY OBJECTIVES

To test diagnostic performance for acute cardiac ischemia (ACI) in a manually calculated and in a computerized, ECG-calculated ACI time-insensitive predictive instrument (ACI-TIPI) in prehospital chest pain patients.

METHODS

We carried out prospective inclusion and data acquisition with retrospective analysis. Over a 6-month period, 439 adult emergency medical services patients with chest pain underwent prehospital electrocardiography. Because of incomplete data, 77 cases were excluded, leaving a study sample of 362 patients. Excluded patients did not differ significantly with respect to age, sex, final diagnosis, or history of myocardial infarction, heart surgery, diabetes, or stroke. ACI-TIPI probabilities of ACI were computed on the basis of the prehospital ECGs as interpreted retrospectively and independently by two study investigators blinded to patient outcome, with a specially programmed electrocardiograph, and with a computer algorithm further modified by logistic-regression analysis.

RESULTS

Diagnostic performance on the basis of receiver operating characteristic (ROC) curve areas of the ACI-TIPI was scored, by the two physician readers, .73 and .74; and by ECG, .75. Patients with low ACI-TIPI probability (0% to 9%) had no acute myocardial infarctions, a 2.3% incidence of angina, and no prehospital life-threatening events.

CONCLUSION

ACI-TIPI probabilities of ACI as generated by a specially programmed electrocardiograph are comparable to those based on physician ECG interpretations and may be useful in the prehospital evaluation of chest pain.

Correlation of rates of coronary artery bypass surgery, angioplasty, and cardiac catheterization in 305 large communities for persons age 65 and older

OBJECTIVE

The rate of coronary artery bypass surgery (CABG) has been shown to vary greatly across geographic regions. This study examined whether these rates were associated with the rate of coronary artery angioplasty (PTCA) and with other community characteristics.

DATA SOURCES/STUDY SETTING

The health care financing administration provided the number of Medicare hospitalizations in 1988 for conditions and procedures related to coronary artery disease. Information on physicians and hospitals was obtained from the Area Resource File, and the number of persons in each age, sex, and race category was obtained from US. census data.

STATISTICAL METHODS

Age-and sex-adjusted hospitalization rates based on the patient's zip code of residence were calculated at the level of the Metropolitan Statistical Area (MSA) for white patients age 65 or older. Rates were obtained for 305 MSAs for CABG, PTCA, cardiac catheterization, angina, and myocardial infarction.

PRINCIPAL FINDINGS

The rate of cardiac catheterization had a correlation of .72 with the CABG rate and .64 with the PTCA rate. The correlation of the PTCA and CABG rates with each other was .49. This correlation was not charged by adjusting for the rates of hospitalization for angina or myocardial infection, but it was reduced to only .05 (ns) after adjusting for the rate of cardiac catheterization. The rates of all three procedures had rank correlations of about .15 with the density of thoracic surgeons and about .30 with the density of hospitals with cardiac catheterization and open heart surgery units.

CONCLUSIONS

Community CABG and PTCA rates tend to move in the same direction due to community factors that also affect the rates of cardiac catheterization. These community factors do not appear to include the rate of coronary artery disease, but may include resources or attitudes toward aggressive treatment of coronary artery disease.

BUN as a risk factor for mortality after coronary artery bypass grafting

BACKGROUND

Although information on blood urea nitrogen (BUN) is universally available for patients who undergo coronary artery bypass grafting, BUN has not often been considered as a risk factor for mortality. This study assessed BUN as a risk factor for CABG patients.

METHODS

Four data sets were evaluated that differed with respect to the types of patients and available patient information. In each of these data sets logistic regression analysis was used to examine the relationship between BUN and mortality after adjusting for other risk factors.

RESULTS

Blood urea nitrogen level was strongly associated with mortality in each of the data sets. After adjustment for the available risk factors other than creatinine level, patients with BUN levels greater than 30 mg/dL had a relative odds of mortality ranging between 1.86 and 2.49 (p < 0.0001 in three of the data sets). Even after adjustment for creatinine level as well as the other variables, BUN was statistically significant at the p less than 0.01 level for three of the data sets.

CONCLUSIONS

The results suggest that BUN provides additional information on cardiac function that supplements the information provided by other risk factors.