The Department of Veterans Affairs' NSQIP: the first national, validated, outcome-based, risk-adjusted, and peer-controlled program for the measurement and enhancement of the quality of surgical care. National VA Surgical Quality Improvement Program

OBJECTIVE

To provide reliable risk-adjusted morbidity and mortality rates after major surgery to the 123 Veterans Affairs Medical Centers (VAMCs) performing major surgery, and to use risk-adjusted outcomes in the monitoring and improvement of the quality of surgical care to all veterans.

SUMMARY BACKGROUND DATA

Outcome-based comparative measures of the quality of surgical care among surgical services and surgical subspecialties have been elusive.

METHODS

This study included prospective assessment of presurgical risk factors, process of care during surgery, and outcomes 30 days after surgery on veterans undergoing major surgery in 123 medical centers; development of multivariable risk-adjustment models; identification of high and low outlier facilities by observed-to-expected outcome ratios; and generation of annual reports of comparative outcomes to all surgical services in the Veterans Health Administration (VHA).

RESULTS

The National VA Surgical Quality Improvement Program (NSQIP) data base includes 417,944 major surgical procedures performed between October 1, 1991, and September 30, 1997. In FY97, 11 VAMCs were low outliers for risk-adjusted observed-to-expected mortality ratios; 13 VAMCs were high outliers for risk-adjusted observed-to-expected mortality ratios. Identification of high and low outliers by unadjusted mortality rates would have ascribed an outlier status incorrectly to 25 of 39 hospitals, an error rate of 64%. Since 1994, the 30-day mortality and morbidity rates for major surgery have fallen 9% and 30%, respectively.

CONCLUSIONS

Reliable, valid information on patient presurgical risk factors, process of care during surgery, and 30-day morbidity and mortality rates is available for all major surgical procedures in the 123 VAMCs performing surgery in the VHA. With this information, the VHA has established the first prospective outcome-based program for comparative assessment and enhancement of the quality of surgical care among multiple institutions for several surgical subspecialties. Key features to the success of the NSQIP are the support of the surgeons who practice in the VHA, consistent clinical definitions and data collection by dedicated nurses, a uniform nationwide informatics system, and the support of VHA administration and managerial staff.

Heavy metal tolerance in the fission yeast requires an ATP-binding cassette-type vacuolar membrane transporter

In response to heavy metal stress, plants and certain fungi, such as the fission yeast Schizosaccharomyces pombe, synthesize small metal-binding peptides known as phytochelatins. We have identified a cadmium sensitive S. pombe mutant deficient in the accumulation of a sulfide-containing phytochelatin-cadmium complex, and have isolated the gene, designated hmt1, that complements this mutant. The deduced protein sequence of the hmt1 gene product shares sequence identity with the family of ABC (ATP-binding cassette)-type transport proteins which includes the mammalian P-glycoproteins and CFTR, suggesting that the encoded product is an integral membrane protein. Analysis of fractionated fission yeast cell components indicates that the HMT1 polypeptide is associated with the vacuolar membrane. Additionally, fission yeast strains harboring an hmt1-expressing multicopy plasmid exhibit enhanced metal tolerance along with a higher intracellular level of cadmium, implying a relationship between HMT1 mediated transport and compartmentalization of heavy metals. This suggests that tissue-specific overproduction of a functional hmt1 product in transgenic plants might be a means to alter the tissue localization of these elements, such as for sequestering heavy metals away from consumable parts of crop plants.

Relation of surgical volume to outcome in eight common operations: results from the VA National Surgical Quality Improvement Program

OBJECTIVE

To examine, in the Veterans Health Administration (VHA), the relation between surgical volume and outcome in eight commonly performed operations of intermediate complexity.

SUMMARY BACKGROUND DATA

In multihospital health care systems such as VHA, consideration is often given to closing low-volume surgical services, with the assumption that better surgical outcomes are achieved in hospitals with larger surgical volumes. Literature data to support this assumption in intermediate-complexity operations are either limited or controversial.

METHODS

The VHA National Surgical Quality Improvement Program data on nonruptured abdominal aortic aneurysmectomy, vascular infrainguinal reconstruction, carotid endarterectomy (CEA), lung lobectomy/pneumonectomy, open and laparoscopic cholecystectomy, partial colectomy, and total hip arthroplasty were used. Pearson correlation, analysis of variance, mixed effects hierarchical logistic regression, and automatic interaction detection analysis were used to assess the association of annual procedure/specialty volume with risk-adjusted 30-day death (and stroke in CEA).

RESULTS

Eight major surgical procedures (68,631 operations) were analyzed. No statistically significant associations between procedure or specialty volume and 30-day mortality rate (or 30-day stroke rate in CEA) were found.

CONCLUSIONS

In VHA hospitals, the procedure and surgical specialty volume in eight prevalent operations of intermediate complexity are not associated with risk-adjusted 30-day mortality rate from these operations, or with the risk-adjusted 30-day stroke rate from CEA. Volume of surgery in these operations should not be used as a surrogate for quality of surgical care.

Factors determining the decision to institutionalize dementing individuals: a prospective study

This longitudinal study of 196 caregiver/care receiver dyads was undertaken to determine the variables predictive of caregiver decision to institutionalize a dependent with dementia. Seven variables (use of services, enjoyment of caregiving, caregiver burden and health, caregiver rating and reaction to care receiver behavior and memory problems, and presence of troublesome behaviors) predicted the decision to institutionalize. Six variables (caregiver health and burden, use of services, care receiver cognitive function and troublesome behaviors, and caregiver reaction to behaviors) predicted actual institutionalization at 18 months.

A decade's experience with quality improvement in cardiac surgery using the Veterans Affairs and Society of Thoracic Surgeons national databases

OBJECTIVE

To review the Department of Veteran Affairs (VA) and the Society of Thoracic Surgeons (STS) national databases over the past 10 years to evaluate their relative similarities and differences, to appraise their use as quality improvement tools, and to assess their potential to facilitate improvements in quality of cardiac surgical care.

SUMMARY BACKGROUND DATA

The VA developed a mandatory risk-adjusted database in 1987 to monitor outcomes of cardiac surgery at all VA medical centers. In 1989 the STS developed a voluntary risk-adjusted database to help members assess quality and outcomes in their individual programs and to facilitate improvements in quality of care.

METHODS

A short data form on every veteran operated on at each VA medical center is completed and transmitted electronically for analysis of unadjusted and risk-adjusted death and complications, as well as length of stay. Masked, confidential semiannual reports are then distributed to each program's clinical team and the associated administrator. These reports are also reviewed by a national quality oversight committee. Thus, VA data are used both locally for quality improvement and at the national level with quality surveillance. The STS dataset (217 core fields and 255 extended fields) is transmitted for each patient semiannually to the Duke Clinical Research Institute (DCRI) for warehousing, analysis, and distribution. Site-specific reports are produced with regional and national aggregate comparisons for unadjusted and adjusted surgical deaths and complications, as well as length of stay for coronary artery bypass grafting (CABG), valvular procedures, and valvular/CABG procedures. Both databases use the logistic regression modeling approach. Data for key processes of care are also captured in both databases. Research projects are frequently carried out using each database.

RESULTS

More than 74,000 and 1.6 million cardiac surgical patients have been entered into the VA and STS databases, respectively. Risk factors that predict surgical death for CABG are very similar in the two databases, as are the odds ratios for most of the risk factors. One major difference is that the VA is 99% male, the STS 71% male. Both databases have shown a significant reduction in the risk-adjusted surgical death rate during the past decade despite the fact that patients have presented with an increased risk factor profile. The ratio of observed to expected deaths decreased from 1.05 to 0.9 for the VA and from 1.5 to 0.9 for the STS.

CONCLUSION

It appears that the routine feedback of risk-adjusted data on local performance provided by these programs heightens awareness and leads to self-examination and self-assessment, which in turn improves quality and outcomes. This general quality improvement template should be considered for application in other settings beyond cardiac surgery.

Comparison of surgical outcomes between teaching and nonteaching hospitals in the Department of Veterans Affairs

OBJECTIVE

To determine whether the investment in postgraduate education and training places patients at risk for worse outcomes and higher costs than if medical and surgical care was delivered in nonteaching settings.

SUMMARY BACKGROUND DATA

The Veterans Health Administration (VA) plays a major role in the training of medical students, residents, and fellows.

METHODS

The database of the VA National Surgical Quality Improvement Program was analyzed for all major noncardiac operations performed during fiscal years 1997, 1998, and 1999. Teaching status of a hospital was determined on the basis of a background and structure questionnaire that was independently verified by a research fellow. Stepwise logistic regression was used to construct separate models predictive of 30-day mortality and morbidity for each of seven surgical specialties and eight operations. Based on these models, a severity index for each patient was calculated. Hierarchical logistic regression models were then created to examine the relationship between teaching versus nonteaching hospitals and 30-day postoperative mortality and morbidity, after adjusting for patient severity.

RESULTS

Teaching hospitals performed 81% of the total surgical workload and 90% of the major surgery workload. In most specialties in teaching hospitals, the residents were the primary surgeons in more than 90% of the operations. Compared with nonteaching hospitals, the patient populations in teaching hospitals had a higher prevalence of risk factors, underwent more complex operations, and had longer operation times. Risk-adjusted mortality rates were not different between the teaching and nonteaching hospitals in the specialties and operations studied. The unadjusted complication rate was higher in teaching hospitals in six of seven specialties and four of eight operations. Risk adjustment did not eliminate completely these differences, probably reflecting the relatively poor predictive validity of some of the risk adjustment models for morbidity. Length of stay after major operations was not consistently different between teaching and nonteaching hospitals.

CONCLUSION

Compared with nonteaching hospitals, teaching hospitals in the VA perform the majority of complex and high-risk major procedures, with comparable risk-adjusted 30-day mortality rates. Risk-adjusted 30-day morbidity rates in teaching hospitals are higher in some specialties and operations than in nonteaching hospitals. Although this may reflect the weak predictive validity of some of the risk adjustment models for morbidity, it may also represent suboptimal processes and structures of care that are unique to teaching hospitals. Despite good quality of care in teaching hospitals, as evidenced by the 30-day mortality data, efforts should be made to examine further the structures and processes of surgical care prevailing in these hospitals.

Selective serotonin reuptake inhibitors: meta-analysis of discontinuation rates

A meta-analysis was carried out of 42 published randomized controlled studies comparing the selective serotonin reuptake inhibitors (SSRIs) with the tricyclic antidepressants (TCAs) that measured discontinuation rates for side effects and lack of efficacy by treatment group in order to compare the discontinuation rates for side effects and lack of efficacy. These discontinuation rates were pooled to produce the main outcome measure. Seven studies were placebo controlled and the discontinuation rates in these studies were also pooled in a separate analysis. Significantly fewer patients receiving SSRIs discontinued treatment because of side effects (14.9%) compared with those receiving TCAs (19%) (p < 0.01). There was also a significant difference in discontinuation rates due to side effects in the placebo- and TCA-controlled studies analysed separately, SSRIs (19%) compared with TCAs (27%) (p < 0.01). In both analyses a similar proportion of patients discontinued for lack of efficacy on SSRIs and TCAs. There is a significant and clinically important advantage for the SSRIs compared with the TCAs in the acceptability of treatment measured by the number of discontinuations due to side effects reported in published studies. The risk-benefit calculation favours the SSRIs since there were similar levels of efficacy but more discontinuations with the TCAs. The selection of an antidepressant for first-line treatment requires critical evaluation of the full risk-benefit equation.

Quantitative trait loci on chromosome 4B for coleoptile length and early vigour in wheat (Triticum aestivum L.)

The Norin-10 dwarfing genes, Rht-B1b (Rht1) and Rht-D1b (Rht2), are commonly used to reduce plant height and increase grain yield in wheat breeding programs. These dwarfing genes lower sensitivity of vegetative tissue to endogenous gibberellin to reduce cell and subsequent stem elongation. This reduction in cell elongation capacity reportedly results in a concomitant reduction in coleoptile length and early vigour (leaf area) thereby affecting seedling establishment and growth. A detailed genetic map from a cross between tall Halberd (Rht-B1a) and semidwarf Cranbrook (Rht-B1b) wheat cultivars was used to assess genetic factors affecting seedling growth. Parental and 150 doubled haploid progeny lines were characterised for seedling and height-related traits in controlled and field environments. Genotypic variation was large and predominantly under additive genetic control with evidence for transgressive segregation for some traits. Narrow-sense heritabilities were moderate to high (h2 = 0.31–0.91) indicating a strong genetic basis for differences between progeny. Molecular marker analyses identified a number of significant (P < 0.05) quantitative trait loci (QTL) for each trait. A major QTL, mapping directly to the Rht-B1 locus on chromosome arm 4BS, accounted for up to 49% of the genotypic variance in peduncle length and plant height, and 27–45% of the genotypic variance in coleoptile length across different temperatures. Another QTL, located close to the RFLP marker XksuC2 on the long arm of chromosome 4B, accounted for 15–27% of the genotypic variance in coleoptile length. The influence of the XksuC2-linked QTL on coleoptile length was greatest at 19˚C and decreased with cooler temperatures. The same QTL affected reductions in leaf size, and both coleoptile tiller size and presence to affect overall seedling vigour. There was also some evidence for epistatic interactions influencing coleoptile tiller growth. Reductions in plant size at the Rht-B1b and XksuC2 loci were associated with presence of the Cranbrook 4B allele. The negative genetic effect of the Rht-B1b dwarfing gene on early growth of wheat confirms phenotypic evidence of a pleiotropic effect of Rht-B1b on establishment and early vigour. Genetic increases in coleoptile length and early leaf area development are likely to be limited in wheat populations containing the Rht-B1b dwarfing gene.

Prevalence of allergic bronchopulmonary aspergillosis and atopy in adult patients with cystic fibrosis

BACKGROUND

Underestimation of allergic bronchopulmonary aspergillosis (ABPA) prevalence in the cystic fibrosis (CF) population is suspected due to nonuniform diagnostic criteria, nonspecific signs and symptoms, assessment during asymptomatic intervals, and physician nonaggressiveness in making the diagnosis.

OBJECTIVE

To define the prevalence of ABPA in adult patients with CF, as the increased duration of bronchiectasis may increase the probability of Aspergillus fumigatus (Af) colonization. We also sought to determine whether atopy increases the prevalence of ABPA in adults with CF.

METHODS

We examined a cross-sectional population of adult patients with CF at the University of Washington for 1 year.

RESULTS

Information was collected on 53 of 65 (82%) patients. Fifteen of 51 (29%) had an immediate skin test reaction to Af, and 30 of 51 (59%) had at least one positive skin test. Increased total serum IgE (>450 IU/mL) was present in 0 of 53; increased IgE-Af and IgG-Af were found in 12 of 53 (23%) and 9 of 53 (17%), respectively; 24 of 53 (45%) had Af-precipitins. Peripheral blood eosinophilia was present in one patient. Eight of 49 (16%) patients' sputum cultures grew Af. ABPA-CB (ABPA-central bronchiectasis) was present in one patient and ABPA-S (ABPA-seropositive) in no patients. Atopy was present in 20 of 51 (39%).

CONCLUSION

There was a low prevalence of ABPA in the adult CF population despite frequent immunologic responses to Af. The prevalence of ABPA was too small to determine an association with atopy.

Human ehrlichiosis in adults after tick exposure. Diagnosis using polymerase chain reaction

OBJECTIVE

To identify and prospectively follow patients with suspected human ehrlichiosis regarding clinical manifestations, laboratory variables, methods for confirming the diagnosis, and complications.

DESIGN

Prospective case study.

SETTING

University and Veterans Affairs hospital and clinics.

PATIENTS

Observations in 30 adult patients with acute febrile illness or with unexplained fevers and cytopenias or abnormal liver profiles or both.

MEASUREMENTS

Serial clinical examinations, hematologic profiles, liver profiles, electrolyte determinations, chest radiographs, and response to therapy; other studies appropriate for patient care.

INTERVENTION

Therapy with doxycycline.

RESULTS

Thirty cases of ehrlichiosis were identified between 1989 and 1992. Tick exposure was strongly associated with the illness (P = 0.0001). Symptoms were nonspecific; fever, chills, and headache predominated but many other symptoms also occurred. Fever and skin rashes with various morphologic characteristics were the most common physical findings. Laboratory investigations indicate that the hematologic, hepatic, and central nervous systems are commonly involved in human ehrlichiosis. Twenty of 23 patients (87%) tested by the polymerase chain reaction using Ehrlichia chaffeensis sequences and whole blood samples were positive for E. chaffeensis.

CONCLUSIONS

The syndrome of human ehrlichiosis is not commonly recognized by physicians. Ehrlichiosis should be considered in the differential diagnosis of patients with febrile illness after known or possible tick exposure, particularly if accompanying cytopenias or abnormal liver profiles or both are present. The therapeutic response to doxycycline is prompt, and complications are uncommon in promptly treated patients. The polymerase chain reaction applied to whole blood samples is a promising test for rapid confirmation of the diagnosis within 24 to 48 hours.

Nontuberculous mycobacterial disease in adult cystic fibrosis patients

This study was conducted to determine the prevalence of mycobacterial disease in an adult cystic fibrosis (CF) population and to determine if there were any patients at higher risk for this disease within the group. Sixty-four patients (28 women, 36 men), ranging in age from 17 to 50 years were screened. One-step purified protein derivative skin testing with controls was performed and sputum was taken for examination. Eight of 64 had positive sputum culture for nontuberculous Mycobacterium. The CF patients with positive mycobacterial sputum cultures tended to be older and to have lower clinical scores than those who did not have Mycobacterium organisms in sputum. Guidelines to determine whether mycobacterial disease or colonization is present should be pursued for the CF population.

Central nervous system manifestations of human ehrlichiosis

Since 1989, we have confirmed the diagnosis of human ehrlichiosis in 57 patients. Although routine radiological studies of the central nervous system (CNS) or analyses of cerebrospinal fluid (CSF) samples were not done for these patients, primary care physicians detected symptoms or signs that prompted them to perform such studies. CSF samples were examined for 15 of the 57 patients. Findings in eight of the 15 CSF samples were abnormal, and the most common abnormalities were lymphocytic pleocytosis and elevated protein levels. A search of the English-language literature revealed 21 additional cases in which CSF examinations were performed; in 13 of these cases, CSF findings were abnormal. The most common clinical finding that predicted CSF abnormalities was a change in mental status. A total of 14 patients underwent computerized tomographic studies, and none of these studies showed abnormalities. Four (19%) of the 21 patients with CNS manifestations of ehrlichiosis and abnormal CSF findings died.

Detection of 31P nuclear magnetic resonance signals in brain by in vivo and freeze-trapped assays

The (31)P NMR spectrum of energy-related metabolites under strictly aerobic conditions in rapidly respiring tissues under physiological conditions has been approached by the study of the (31)P NMR signals in vivo and in freeze-trapped organs. Freezing the head of the anesthetized animal by liquid N(2), excision of the brain tissue (white and gray matter) at -196 degrees , and transfer to the NMR tube occurs without alteration of the metabolite concentrations. The sample is warmed to the region -15 degrees to -10 degrees , at which temperatures there is sufficient mobility for recording (31)P NMR at concentrations characteristic of brain tissues ( approximately 5 mM) with an adequate signal to noise ratio in 10 min but insufficient mobility for significant enzymatic activity. A approximately 0.4-sec acquisition time is adequate for nuclear relaxation and a 10-min scan gives an adequate signal to noise ratio. Metabolism of creatine phosphate, P(i), and sugar phosphates occurs by 1 hr at -10 degrees and 2 hr at -12 degrees . Extrapolation of the approximately zero order kinetics of disappearance of creatine phosphate and appearance of P(i) suggests that <10% of these two metabolites has been altered in the time of the first measurement.A comparison of the freeze-trapped state and the in vivo metabolite pattern is afforded in preliminary experiments on the head of the living mouse (brain and skeletal tissue) in aerobic and anaerobic states. Longer relaxation times and mild hypoxia due to the restricted diameter of the NMR tube gives significantly lower creatine phosphate/ATP values for this condition. Both direct in vivo and freeze-trapped assays of energy-related metabolites afford excellent approaches to the detection of anoxia and to the evaluation of metabolic control in hypoxic conditions.

Review of wheat improvement for waterlogging tolerance in Australia and India: the importance of anaerobiosis and element toxicities associated with different soils

BACKGROUND AND AIMS

The lack of knowledge about key traits in field environments is a major constraint to germplasm improvement and crop management because waterlogging-prone environments are highly diverse and complex, and the mechanisms of tolerance to waterlogging include a large range of traits. A model is proposed that waterlogging tolerance is a product of tolerance to anaerobiosis and high microelement concentrations. This is further evaluated with the aim of prioritizing traits required for waterlogging tolerance of wheat in the field.

METHODS

Waterlogging tolerance mechanisms of wheat are evaluated in a range of diverse environments through a review of past research in Australia and India; this includes selected soils and plant data, including plant growth under waterlogged and drained conditions in different environments. Measurements focus on changes in redox potential and concentrations of diverse elements in soils and plants during waterlogging.

KEY RESULTS

(a) Waterlogging tolerance of wheat in one location often does not relate to another, and (b) element toxicities are often a major constraint in waterlogged environments. Important element toxicities in different soils during waterlogging include Mn, Fe, Na, Al and B. This is the first time that Al and B toxicities have been indicated for wheat in waterlogged soils in India. These results support and extend the well-known interactions of salinity/Na and waterlogging/hypoxia tolerance.

CONCLUSIONS

Diverse element toxicities (or deficiencies) that are exacerbated during waterlogging are proposed as a major reason why waterlogging tolerance at one site is often not replicated at another. Recommendations for germplasm improvement for waterlogging tolerance include use of inductively coupled plasma analyses of soils and plants.

Pneumonia in the immunocompetent patient

Pneumonia is an acute inflammation of the lower respiratory tract. Lower respiratory tract infection is a major cause of mortality worldwide. Pneumonia is most common at the extremes of life. Predisposing factors in children include an under-developed immune system together with other factors, such as malnutrition and over-crowding. In adults, tobacco smoking is the single most important preventable risk factor. The commonest infecting organisms in children are respiratory viruses and Streptoccocus pneumoniae. In adults, pneumonia can be broadly classified, on the basis of chest radiographic appearance, into lobar pneumonia, bronchopneumonia and pneumonia producing an interstitial pattern. Lobar pneumonia is most commonly associated with community acquired pneumonia, bronchopneumonia with hospital acquired infection and an interstitial pattern with the so called atypical pneumonias, which can be caused by viruses or organisms such as Mycoplasma pneumoniae. Most cases of pneumonia can be managed with chest radiographs as the only form of imaging, but CT can detect pneumonia not visible on the chest radiograph and may be of value, particularly in the hospital setting. Complications of pneumonia include pleural effusion, empyema and lung abscess. The chest radiograph may initially indicate an effusion but ultrasound is more sensitive, allows characterisation in some cases and can guide catheter placement for drainage. CT can also be used to characterise and estimate the extent of pleural disease. Most lung abscesses respond to medical therapy, with surgery and image guided catheter drainage serving as options for those cases who do not respond.

Risk factors for intermediate-term survival after coronary artery bypass grafting

BACKGROUND

Risk factors for short-term mortality after coronary artery bypass grafting are well established, but little is known about risk factors for intermediate-term mortality.

METHODS

We analyzed the outcomes of 11,815 patients undergoing coronary artery bypass grafting in one of the 43 cardiac surgery programs of the Department of Veteran Affairs. Risk factors for intermediate- and short-term mortality were determined using Cox proportional hazards regression models. Effects of risk factors during these two periods were explicitly compared.

RESULTS

We found important differences in mortality risk-factor sets between the intermediate- and short-term periods after coronary artery bypass grafting. The majority of predictors of intermediate-term mortality were noncardiac-related variables, whereas the majority of predictors of short-term mortality were cardiac-related variables. Impaired functional status, chronic obstructive pulmonary disease, and renal dysfunction had greater effects in the intermediate-term period. Previous heart operation, angina class III or IV, previous myocardial infarction, and preoperative use of an intraaortic balloon pump had greater effects in the short-term period.

CONCLUSIONS

The risk factors for intermediate-term mortality identified in this study can augment preoperative risk assessment and counseling of patients. Clinicians should be aware of the importance of noncardiac-related variables as predictors of mortality in the intermediate-term period after coronary artery bypass grafting.

Real-time cross-sectional echocardiographic diagnosis of coarctation of the aorta: a prospective study of echocardiographic-angiographic correlations

Real-time cross-sectional echocardiographic sector scan examinations were performed from a suprasternal notch location to image aortic anatomy in 15 children (ages 1 day to 21 years) who were subsequently shown at cardiac catheterization to have coarctation of the descending thoracic aorta. The resulting echocardiographic images of the ascending, transverse and descending aorta imaged juxtaductal coarctation in all 15 patients. Echocardiography predicted discrete coarctation of the aorta in eight, isthmic hypoplasia in two, hourglass type coarctation deformities in three and longer segment coarctation in four patients. Catheterization and angiography confirmed all of these anatomic observations. The control group, 100 patients with congenital heart disease but without angiographic coarctations, included four patients with right-sided aortic arch and six patients with dextrocardia. The ascending, transverse and descending aorta were adequately imaged in 94 of these and no descending aortic abnormalities were noted. This study shows the potential utility of cross-sectional echocardiography for the noninvasive precatheterization or preoperative assessment of coarctation of the aorta in children and critically ill newborns.

Heat-related deaths in Philadelphia--1993

A study of heat-related deaths associated with the 1993 heat wave in Philadelphia, Pennsylvania, was conducted. Most of these deaths were in the susceptible elderly with preexisting natural diseases who lived alone without air conditioning in upstairs bedrooms with windows shut, thus creating an even hotter environment. These excessive deaths under such conditions did not meet the standard clinical criteria for hyperthermia because of varying postmortem intervals. Therefore, the authors stress the utility of a postmortem definition of heat-related death to better define the magnitude of health risk posed by hot weather and warn public health and other agencies to take preventative measures.

Defective chemotaxis and calcium response in localized juvenile periodontitis neutrophils

Localized juvenile periodontitis (ljp) is an early onset form of periodontal disease characterized by unique localization to first molars and incisors and a high prevalence of neutrophil abnormalities, particularly chemotaxis. The intracellular transduction mechanisms that follow receptor-ligand coupling on the neutrophil surface and lead to chemotaxis are not clearly established. Chemotaxis and phagocytosis are modulated by a variety of receptors and involve several activation pathways; the role of intracellular calcium as a presumptive second messenger and mediator of these events is well established. The putative effector mechanisms for the chemotactic receptor of neutrophils also include the possible activation of a phospholipase, protein kinase C, methyltransferase, or adenylate cyclase. In normal neutrophils, a phosphoinositide pathway initiated by phospholipase C, which results in the activation of protein kinase C via diacylglycerol and the generation of IP3, has been implicated. In order to better understand the stages of neutrophil transduction, fluorescent probes were used to monitor neutrophil calcium changes. Chlorotetracycline (CTC) was used as an indirect probe of intracellular membrane-bound pool of calcium stores, and Quin-2 was used to monitor cytosolic free calcium levels of FMLP stimulated normal and LJP neutrophils. The results indicate that the early phase of the calcium response affiliated with the release of intracellularly sequestered calcium appears intact in LJP neutrophils, as the CTC fluorescence changes were similar to control values. The second phase of the calcium response, associated with membrane channel activation and an influx of extracellular calcium, appeared compromised in the neutrophils of the LJP population.(ABSTRACT TRUNCATED AT 250 WORDS)

Proteinase inhibitors from Nicotiana alata enhance plant resistance to insect pests

The ornamental tobacco (Nicotiana alata) produces one 6-kDa chymotrypsin inhibitor and four 6-kDa trypsin inhibitors from a single 40.3-kDa precursor protein. Three different approaches have been used to assess the potential of these proteinase inhibitors (PIs) in insect control. The first was an in-vitro approach in which all five inhibitors, the single chymotrypsin inhibitor or three of the four trypsin inhibitors were tested for their ability to inhibit gut protease activity in insects from four orders. The second approach was to incorporate the N. alata PIs in the artificial diet of the native budworm (Helicoverpa punctigera) and the black field cricket (Teleogryllus commodus). H. punctigera larvae and T. commodus nymphs had a significant (P<0.01) reduction in growth after ingestion of the PI and were more lethargic than insects on the control diet. Several of the H. punctigera larvae also failed to complete moulting at the third or fourth instar. The third approach was to express the N. alata PIs in transgenic tobacco under the control of the 35S CaMV promoter. When H. punctigera larvae were fed tobacco leaves expressing the N. alata PIs at 0.2% soluble protein, significant (P<0.01) differences in mortality and/or growth rate were observed.

Lymphocytosis of gamma/delta T cells in human ehrlichiosis

The majority of T cells in peripheral blood express a T-cell receptor (TCR) comprised of alpha and beta chains. An alternate form of the TCR is comprised of gamma and delta chains. These gamma/delta T cells are associated with certain infectious lesions, and modestly elevated in peripheral blood in certain disease states. Human ehrlichiosis is characterized by hematologic abnormalities including multi-lineage cytopenias. In most cases reported, a lymphocytopenia has been present either at diagnosis, or at some time during the illness. Early in the course of antibiotic treatment (48-72 hours), the lymphocytopenia corrects itself and is rapidly followed by a lymphocytosis of T cells that express CD3, but are negative for CD4 and CD8, as well as the major form of the TCR formed by the alpha/beta heterodimer. Instead, these CD3+4-8- T cells express the gamma/delta heterodimer associated with V gamma 9 and V delta 2 chains, a population of cells usually the distinctive minority of peripheral blood T cells, but constituting the major phenotype of peripheral gamma/delta T cells.

Marker-assisted estimation of quantitative genetic parameters in rainbow trout, Oncorhynchus mykiss

Estimation of quantitative genetic parameters conventionally requires known pedigree structure. However, several methods have recently been developed to circumvent this requirement by inferring relationship structure from molecular marker data. Here, two such marker-assisted methodologies were used and compared in an aquaculture population of rainbow trout (Oncorhynchus mykiss). Firstly a regression-based model employing estimates of pairwise relatedness was applied, and secondly a Markov Chain Monte Carlo (MCMC) procedure was employed to reconstruct full-sibships and hence an explicit pedigree. While both methods were effective in detecting significant components of genetic variance and covariance for size and spawning time traits, the regression model resulted in estimates that were quantitatively unreliable, having both significant bias and low precision. This result can be largely attributed to poor performance of the pairwise relatedness estimator. In contrast, genetic parameters estimated from the reconstructed pedigree showed close agreement with ideal values obtained from the true pedigree. Although not significantly biased, parameters based on the reconstructed pedigree were underestimated relative to ideal values. This was due to the complex structure of the true pedigree in which high numbers of half-sibling relationships resulted in inaccurate partitioning of full-sibships, and additional unrecognized relatedness between families.

Acremonium endophytes in perennial ryegrass and other pasture grasses in Australia and New Zealand

Many grasses contain asymptomatic fungal endophytes which are now recognised as having a major impact on the performance of pastures in Australia and New Zealand, and elsewhere in the world. The association between the plant and the fungus is regarded as mutualistic, with the host grass able to benefit from endophyte presence through reduced herbivore feeding, increased resistance to insects, improved plant growth and possibly disease resistance. Grazing systems may be disadvantaged, however, as the ingestion of endophyte-infected grasses can be associated with a number of animal toxicoses including ryegrass staggers and fescue toxicosis. There is increasing evidence that the effects of endophyte on the host grass, and consequently on pasture performance and animal production, are mediated by a range of secondary metabolites produced by the plant-fungus interaction. Recent work has shown that a great deal of variation can be found amongst endophyte strains both in the types and amounts of these secondary metabolites produced. This review presents the current status of knowledge on the impact of endophyte on pasture grasses in Australia and New Zealand and attempts to place it in the framework of endophyte research in general. It discusses the potential for harnessing the benefits of endophyte infection, whilst minimizing deleterious effects, through the use of elite endophyte strains which have been isolated from naturally occurring grasses, or modified by the techniques of genetic engineering. It concludes by identifying a number of significant areas which require further research for us to fully understand the plant-fungus interaction and its effects on pasture systems.

Genetic markers for ancestry are correlated with body composition traits in older African Americans

Individual-specific percent European ancestry was assessed in 1,277 African Americans. We found significant correlations between proportion of European ancestry and several musculoskeletal traits, indicating that admixture mapping may be a useful strategy for locating genes affecting these traits.

INTRODUCTION

Genotype data for admixed populations can be used to detect chromosomal regions influencing disease risk if allele frequencies at disease-related loci differ between parental populations. We assessed evidence for differentially distributed alleles affecting bone and body composition traits in African Americans.

METHODS

Bone mineral density (BMD) and body composition data were collected for 1,277 African and 1,790 European Americans (aged 70-79). Maximum likelihood methods were used to estimate individual-specific percent European ancestry for African Americans genotyped at 37 ancestry-informative genetic markers. Partial correlations between body composition traits and percent European ancestry were calculated while simultaneously adjusting for the effects of covariates.

RESULTS

Percent European ancestry (median = 18.7%) in African Americans was correlated with femoral neck BMD in women (r = -0.18, p < 10(-5)) and trabecular spine BMD in both sexes (r = -0.18, p < 10(-5)) independently of body size, fat, lean mass, and other covariates. Significant associations of European ancestry with appendicular lean mass (r = -0.19, p < 10(-10)), total lean mass (r = -0.12, p < 10(-4)), and total body fat (r = 0.09, p < 0.002) were also observed for both sexes.

CONCLUSIONS

These results indicate that some population differences in body composition may be due to population-specific allele frequencies, suggesting the utility of admixture mapping for identifying susceptibility genes for osteoporosis, sarcopenia, and obesity.

Magnetic resonance imaging of muscle in amyotrophic lateral sclerosis

OBJECTIVE

To characterize leg muscle abnormalities in patients with ALS using MRI, and to correlate MRI with standard neurologic measures of motor neuron dysfunction.

METHODS

Eleven ALS patients were studied twice (once at baseline and again after 4 months) and compared with eight normal control subjects. MRI data of the lower extremities were compared with tibialis anterior compound muscle action potential amplitude (CMAPa) and foot dorsiflexion maximal voluntary isometric contraction (MVIC).

RESULTS

Muscle MRI was abnormal by visual inspection in six of 11 patients. The mean muscle T1 time and muscle volume were not different in patients compared with normal control subjects (p > 0.1). However, the mean T2 times were increased in the patients compared with normal control subjects (p = 0.009). T1 times did not correlate with CMAPa or MVIC. Muscle volume correlated with MVIC (r = 0.73 to 0.78, p < 0.02) but not with CMAPa (p > 0.05). There was a strong negative correlation (r < -0.8, p < or = 0.01) between muscle T2 time and MVIC and CMAPa. Also, the change in T2 relaxation time correlated with the change in CMAPa as the disease progressed (r = -0.63, p = 0.037).

CONCLUSION

Of the MRI characteristics studied, T2 relaxation time was the best indicator of motor neuron dysfunction and may have a role in objective evaluation of motor neuron dysfunction.