Salmonella typhimurium aroB mutants are attentuated in BALB/c mice

The aroB gene of Salmonella typhimurium, encoding dehydroquinate synthase, has been cloned into pUC19 and the DNA sequence determined. The aroB gene was isolated from a cosmid gene bank by complementation of an Escherichia coli aroB mutant and screening by Southern blot analysis. The nucleotide sequence of the S. typhimurium aroB gene revealed the presence of an open reading frame, encoding a protein of 362 amino acids with a calculated molecular mass of 38696 Daltons. The amino acid sequence of S. typhimurium dehydroquinate synthase is nearly identical to the E. coli homologue and shows high homology with other aroB gene products from other organisms. Subsequently, a stable insertional mutation in aroB was introduced into the wild-type S. typhimurium C5 strain. This mutant was auxotrophic for aromatic compounds. Infection of BALB/c mice with this mutant demonstrated attenuation comparable to other S. typhimurium mutants unable to biosynthesize aromatic amino acids.

A new method for studying the selective adherence of blood lymphocytes to the microvasculature of human retina

PURPOSE

To develop a sensitive and reproducible technique for measuring the adherence of blood lymphocytes to vessel walls exposed in sections of human retina and for examining the role of lymphocyte and vascular adhesion molecules in these events.

METHODS

Cryostat sections of human retina were overlaid with blood lymphocytes from healthy subjects, and experimental conditions were sought by which preferential attachment of the cells occurred to blood vessel walls in the retinal sections. Adherent lymphocytes were identified by staining with methyl green-thionine, and transected blood vessels were identified by their structure and by staining of basement membranes with periodic acid-Schiff. The adherence of enriched preparations of CD4+ (T-helper) and CD8+ (T-cytotoxic) lymphocytes, of interleukin-2 (IL-2)-activated cells, and of lymphocytes from patients with ocular Behçet's disease was examined. The distribution of adhesion molecules on retinal vessel walls was determined by immunohistochemistry, and the contribution of leukocyte integrins to lymphocyte binding was studied by blocking experiments with monoclonal antibodies.

RESULTS

The optimal selectivity of blood lymphocyte attachment to retinal vessel walls occurred when purified lymphocytes were suspended in culture medium with 10% fetal calf serum and overlaid onto retinal sections for 30 minutes at 23 degrees C with gentle agitation. Under these conditions, 92% of the lymphocytes that adhered to the section were confined to the retinal microvasculature, and CD4+ T cells were more adherent than CD8+ T cells (P < 0.01). Prior exposure of normal lymphocytes to IL-2 enhanced their binding to retinal blood vessels, and lymphocytes from patients with Behçet's disease showed supranormal vascular adherence (P < 0.005). Many transected vessels stained positively for CD31; PECAM (mean 62%), CD54; ICAM-1 (mean 73%), CD62E; E-selectin (mean 35%), CD62P; P-selectin (mean 61%), and CD106; VCAM-1 (mean 42%). However, these vascular adhesion molecules occupied < 20% of the area of the blood vessel walls. Lymphocyte adhesion to the retinal vessels was more dependent on CD29 (the common chain of the beta 1 integrins) expression than either CD11a/CD18 or CD49d.

CONCLUSIONS

This technique allows measurements to be made of lymphocyte adherence to vascular and nonvascular structures of retina ex vivo. Extension of this approach to the study of leukocyte adherence to sections of pathologic retina may be of clinical and experimental applicability in understanding mechanisms of retinal inflammation.

Nonmalignant disorders of lymphocytes

OBJECTIVE

To review the etiology, pathophysiology, clinical features, and laboratory findings in nonmalignant disorders of lymphocytes.

DATA SOURCES

Current literature.

STUDY SELECTION

Determined by author.

DATA EXTRACTION

Determined by author.

DATA SYNTHESIS

Assessing qualitative and quantitative changes in lymphocytes provides important information regarding immune reactions, disease conditions, and responses to therapy. Quantitative nonmalignant disorders encompass those conditions in which the total number of lymphocytes may be either increased (lymphocytosis) or decreased (lymphocytopenia). Frequently encountered disorders with a lymphocytosis include infectious mononucleosis and cytomegalovirus infection. Lymphocytopenia is not detected as often or as easily in the clinical laboratory, but may be induced by several causes such as stress, certain types of therapy, nutrient deficiencies, or premature destruction of lymphocytes as occurs in acquired immunodeficiency syndrome. Clinical and laboratory findings provide significant clues in defining the etiology of a nonmalignant disorder of lymphocytes.

CONCLUSION

Disorders of lymphocytes include both benign and malignant quantitative and qualitative variations. A reactive lymphocytosis is commonly associated with many viral and certain bacterial infections. The clinical laboratory plays an important role in differentiating reactive and malignant lymphoproliferative processes. Benign lymphocytopenia, although not a frequent finding, must also be characterized by the laboratory.

Minimal criteria for placement of adults on the liver transplant waiting list: a report of a national conference organized by the American Society of Transplant Physicians and the American Association for the Study of Liver Diseases

This report summarizes a recent meeting cosponsored by the American Society of Transplant Physicians and the American Association for the Study of Liver Diseases to formulate minimal criteria by which patients with severe liver disease will be placed on the waiting list for liver transplantation. The participants agreed that only patients in immediate need of liver transplantation should be placed on the waiting list. Patients should not be placed in anticipation of some future need for such therapy. It was agreed that minimal criteria could assist but not replace the clinical judgment of the transplant professionals at individual centers. The criteria will be summarized below for adult patients with acute or chronic liver disease. The most important non-disease-specific criterion for placement on the transplant waiting list was an estimated 90% chance of surviving 1 year. This translated into a Child-Pugh score of > or = 7 for patients with cirrhosis which places the patient in Child-Pugh class B or C. Cirrhotic patients who have experienced gastrointestinal bleeding caused by portal hypertension or a single episode of spontaneous bacterial peritonitis would meet the minimal criteria irrespective of their Child-Pugh score. There were disease-specific criteria also. These include a sole minimal criterion for patients with fulminant hepatic failure regardless of etiology of the onset of stage 2 hepatic encephalopathy. A requirement for 6 months abstinence from alcohol before placement on the transplant waiting list was considered appropriate for most patients with alcoholic liver disease. Exceptional cases could get access to the waiting list through a regional review process. Chronic cholestatic diseases present difficulties because of a different natural history than that of chronic hepatocellular diseases. The use of specific risk scores for primary biliary cirrhosis and primary sclerosing cholangitis will likely replace Childs-Pugh classification as the scoring systems become refined. Minimal criteria for any patient with a primary hepatocellular cancer would admit any patient with a tumor confined to the liver irrespective of size or number of tumors, after careful investigation had failed to show spread to lymph nodes, the portal vein, or distant organs. Unusual or rare indications for liver transplantation, including Budd-Chiari syndrome, Wilson's disease, and other hereditary disorders, were also discussed. Finally, it was agreed that there should be no absolute contraindications to placement of patients on the liver transplant waiting list. These criteria should be open to regular review to accommodate advances in the field.

Adhesion molecules are upregulated on dendritic cells isolated from human blood

This study investigated whether the high expression of adhesion molecules on enriched preparations of circulating dendritic cells (DCs) was an intrinsic property of the cells or whether it was a consequence of the procedure used to isolate them from blood. Expression of the beta 1, beta 2 integrins (CD11/CD18 family) and other adhesion molecules on DCs in whole blood was compared with that on isolated DCs. Dendritic cells were identified by flow cytometry as leucocytes that were positive for human leucocyte antigen (HLA)-DR, but negative for CD3, CD14, CD16, CD19 and CD56. In contrast to a minority of DCs in whole blood, the majority of isolated DCs expressed the beta 2 integrins and there were a greater number of cells bearing CD44, CD54 and some of the beta 1 integrins (notably CD49b, CD49d, CD49e and CD29). An increase in the proportion of DCs bearing adhesion molecules was generally apparent at the isolation stage when mononuclear cells, which had been incubated overnight, were centrifuged on a metrizamide gradient to enrich for cells of low density. Inclusion of an inhibitor of protein glycosylation and exocytosis (brefeldin A) at all stages of separation partially prevented an increase in the percentage of DCs bearing CD18, C29 and C54 whereas the inclusion of cycloheximide (an inhibitor of polypeptide synthesis) interfered with increases in the percentage of cells bearing CD29 and CD54. Neither of these antagonists had an effect on the intensity of adhesion molecule expression. We suggest that some of the adhesion-dependent functions of isolated DCs are caused, in part, by an upregulation of surface adhesion molecules induced by the enrichment procedure.

Extreme social isolation, use of community-based senior support services, and mortality among African American elderly women

The effect of extreme social isolation and use of community-based senior services on longevity was examined in a national sample of African American elderly women (ages 55-96). Consistent with previous research on the social integration/mortality link, African American elderly women who were extremely socially isolated were hypothesized to have a higher 5-year mortality rate. It was also hypothesized that use of community senior services would be negatively associated with 5-year mortality. Results of logistic regression analysis controlling for age, education, income, and health status found that extremely socially isolated African American elderly women were three times more likely than the nonisolated women to die within the 5-year period from the initial survey. Use of community senior services did not have a relationship on mortality. Results are discussed in terms of directions for future research and intervention.

Neutrophil adhesion molecule expression during cardiopulmonary bypass: a comparative study of roller and centrifugal pumps

The purpose of this study was to determine whether adhesion molecules and markers of cell activation were preferentially increased on blood neutrophils during cardiopulmonary bypass (CPB) and whether such effects were influenced by the use of a roller pump or a centrifugal pump. Forty-six patients undergoing open heart surgery were randomly allocated into either the roller or centrifugal groups. Blood (1 ml volumes) was removed from arterial and venous lines immediately before and 1 h after the start of bypass. Whole blood samples were immunolabelled and flow cytometry used to measure the distribution and expression of the adhesion molecules CD11b, CD18, CD62L on neutrophils, monocytes and lymphocytes, in addition to CD64 on neutrophils and monocytes, and CD14 on monocytes. The expression of CD11b was significantly enhanced on neutrophils in arterial and venous samples from both the roller pump (mean 84% and 100% increase, respectively; p < 0.001) and centrifugal pump (mean 74% and 73% increase, respectively; p < 0.001) groups. Neutrophil L-selectin expression increased to a small but significant extent in arterial and venous samples from the centrifugal pump group (mean 16% increase; p < 0.001) and in venous samples from the roller pump group (mean 10% increase; p < 0.01). Neither the percentage of neutrophils bearing CD11b/CD18, CD62L and CD64, nor the expression of adhesion molecules on lymphocytes and monocytes were modified by 1 h of bypass. These results suggest that patients subjected to CPB with roller or centrifugal pumps are equally at risk to neutrophil activation that could lead to increased interaction of these cells with blood vessel walls.

Genetic heterogeneity in Schwartz-Jampel syndrome: two families with neonatal Schwartz-Jampel syndrome do not map to human chromosome 1p34-p36.1

Schwartz-Jampel syndrome (SJS) is a rare autosomal recessive disorder characterised by the presence of myotonia with a mask-like face, skeletal dysplasia, and growth retardation. Two types have been defined by the age of manifestation of the symptoms. Linkage of Schwartz-Jampel syndrome to human chromosome 1p34-p36.1 has been shown in families where probands presented during infancy or early childhood. We have investigated two well documented families segregating severe neonatal SJS with microsatellite markers spanning the critical region of 1p34-p36. No demonstrable linkage to chromosome 1 was found in either family, suggesting that a second locus is responsible for the severe form of neonatal Schwartz-Jampel syndrome.

Safety of early intravenous dipyridamole technetium 99m sestamibi SPECT myocardial perfusion imaging after uncomplicated first myocardial infarction. Early Post MI IV Dipyridamole Study (EPIDS)

We assessed the safety of early (2 to 4 days) intravenous dipyridamole infusion in conjunction with technetium 99m sestamibi tomographic myocardial perfusion imaging in patients with first myocardial infarction (MI). Early risk stratification with myocardial perfusion imaging of patients after acute MI may be useful to identify patients who either require further evaluation or may be safely discharged. Because of minimal hemodynamic effects, intravenous dipyridamole may be a safe means of producing hyperemia for myocardial perfusion imaging. Stable patients with first acute MI who met entry criteria were randomized (3:1) to either intravenous dipyridamole infusion (0.56 mg/kg over a 4-minute period) 48 to 96 hours after onset of symptoms or a control (no test) group. Adverse cardiac events (unstable angina, recurrent MI, or cardiac death) were evaluated during and 24 hours after the dipyridamole infusion and during the corresponding 24 hours for the control group. Two hundred eighty-four patients received dipyridamole infusion a mean time of 3.3 +/- 0.7 days after MI. There were no adverse clinical events either during or immediately after the infusion. During the 24 hours after infusion, three patients had symptoms of unstable angina pectoris, one patient had a recurrent MI, and no patients died. The earliest event occurred 4.2 hours after the dipyridamole infusion. Three patients had unstable angina pectoris, whereas no patients had either recurrent MI or died in the control group. There were no statistically significant differences between the two groups. In a multicenter trial, dipyridamole infusion administered early after the first acute MI resulted in no increased evidence of cardiac events either immediately or 24 hours after the procedure compared with a control group. Therefore intravenous dipyridamole can be safely used as a pharmacologic vasodilator for myocardial perfusion imaging soon after uncomplicated MI.

Lymphocyte-endothelial cell interactions in multiple sclerosis: disease specificity and relationship to circulating tumour necrosis factor-alpha and soluble adhesion molecules

This study addressed two questions; first, whether the supranormal adherence of blood lymphocytes from patients with multiple sclerosis (MS) to endothelial cell monolayers treated with tumour necrosis factor-alpha (TNF alpha) was a feature common to other inflammatory disorders; and second, whether the adherence properties of blood lymphocytes from MS patients were related to changes in disease activity and to levels of circulating TNF alpha and soluble adhesion molecules. In the first part of the investigation, lymphocytes from 14 patients with MS were more adherent to TNF alpha-treated endothelial cells (P < 0.01) than those from healthy controls, whereas the adherence properties of lymphocytes from 12 patients with rheumatoid arthritis, eight patients with psoriasis and ten patients with neurological diseases other than MS were normal. In the second phase of the work, measurement of the adhesive properties of lymphocytes isolated at monthly intervals from a further six MS patients over a 5-8 month period, found that changes in binding to TNF alpha-treated endothelial cells, directly paralleled changes in circulating levels of TNF alpha (r = 0.77; P < 0.001) and soluble vascular cell adhesion molecule-I (sVCAM-1) r = 0.67; P = 0.001). An increase in disease activity, measured by T2-weighted and gadolinium-enhanced magnetic resonance imaging of the central nervous system (CNS), occurred in two patients and was associated with heightened lymphocyte adhesiveness and a rise in serum TNF alpha levels. Further analysis of the 34 serum samples from the six MS patients revealed a direct relationship between the concentration of sL-selectin and soluble intercellular adhesion molecule-I (sICAM-I) (r = 0.65; P < 0.001) and between sL-selectin and sTNF alpha (r = 0.42; P < 0.02). These findings support the view that disease activity in MS is associated with an increased adhesive interaction of blood lymphocytes with vascular endothelium at inflammatory sites within the CNS.

Alcohol use after liver transplantation in alcoholics: a clinical cohort follow-up study

The purposes of this study were to determine among a cohort of long-term alcoholic survivors after liver transplantation (1) the incidence of alcohol use, (2) its effect on allograft integrity and extrahepatic health, and (3) the validity of the pretransplant alcohol prognosis screening process. Retrospective clinical cohort study of all alcoholic patients undergoing orthotopic liver transplantation at a single center from February 1987 until January 1991 with follow-up through December 1994, giving a median duration of follow-up of 63 months (range, 6-89 months). Multidisciplinary liver transplantation program at a tertiary-care academic medical center. Fifty alcoholic, long-term liver transplant recipients. The frequency of alcohol relapse, defined as any alcohol use in the period after transplantation, was determined by two questionnaire studies and by clinical follow-up. Allograft integrity was assessed by coded review of serial percutaneous allograft biopsies. Potential systemic effects of alcohol relapse were assessed by chart review. The alcohol prognosis screening process was evaluated by retrospectively comparing pretransplant estimates of putative indicators of alcoholism prognosis in posttransplant alcohol users and abstainers. Thirty-three recipients (66%) consistently denied any alcohol use throughout the duration of posttransplant follow-up, whereas 17 (34%) were identified as having consumed alcohol at least once since the transplant. There were no significant differences at the time of evaluation between abstainers and alcohol users in age, sex distribution, severity of liver dysfunction, median duration of abstinence, or University of Michigan alcoholism prognosis score. The median interval from transplantation to alcohol relapse was 17 months, with a range of 3 to 45 months. Recurrent alcohol use was associated with significant medical complications sufficient to require admission to the hospital in 6 patients. One patient died of graft dysfunction, noncompliance with immunosuppressant medications, and presumed graft rejection while drinking. Mild or progressive hepatitis, which was the most common abnormality in posttransplant liver biopsy findings, was equally distributed between both alcohol users and abstainers and sometimes occurred in the absence of antibody to hepatitis C virus antibodies. There was a similar frequency of biopsy-proven acute cellular rejection in alcohol users and abstainers. Typical histological features of alcoholic liver injury were present in posttransplant biopsies from 1 alcohol user only. Alcohol use by alcoholics is uncommon in the first 5 years after liver transplantation, and alcohol-associated liver injury is unusual. Mild nonspecific hepatitis is common in both alcohol users and nonusers alike. Among a small subset of alcoholic transplant recipients, drinking behavior after liver transplantation is associated with considerable morbidity, requiring hospital admissions and occasionally leading to graft loss and death.

Human blood dendritic cells: binding to vascular endothelium and expression of adhesion molecules

To investigate the binding properties of dendritic cells (DC) to vascular endothelium, a comparative analysis was undertaken of DC, monocytes and lymphocytes isolated from the blood of 25 healthy subjects using monolayers of human umbilical vein endothelial cells as the adherence substrate. More blood DC (mean 24% adherence) were adherent to endothelial monolayers than monocytes (mean 18%; P < 0.001) and lymphocytes (mean 12%; P < 0.001). When the monolayers were pretreated with tumour necrosis factor-alpha (TNF-alpha) all leucocyte populations exhibited an increased attachment, but there was still greater binding of DC (mean 37% adherence) in comparison with monocytes (mean 23%; P < 0.001) and lymphocytes (mean 18%; P < 0.001). Flow cytometric analysis revealed that in relation to monocytes and lymphocytes the DC had a higher surface expression of the adhesion molecules CD11a (P < 0.05), CD11c (P < 0.005) and CD54 (P < 0.005) but a lower prevalence of cells bearing CD49d (mean 38%; P < 0.05) and the homing receptor CD62L (mean 14%; P < 0.001). CD1a was present on 22% of DC and virtually absent from the surface of monocytes and lymphocytes. The intensity of expression of the beta1-integrins, CD49c, CD49d and CD49e was greater on DC than lymphocytes and monocytes (P < 0.05). Antibody blocking studies demonstrated that DC binding to untreated and TNF-alpha-treated endothelium was dependent upon the expression of CD11a, CD18 and CD49d, and the simultaneous application of anti-CD18 and anti-CD49d antibodies produced an approximate 70% inhibition of adhesion (P < 0.001). Thus, the expression of both beta1- and beta2-integrins contributes to the adhesive interaction between DC and endothelium.

Differential immunohistochemical staining for DNA topoisomerase II alpha and beta in human tissues and for DNA topoisomerase II beta in non-Hodgkin's lymphomas

Topoisomerase II (Topo II) is the target for several chemotherapeutic agents, including doxorubicin and etoposide, termed Topo II poisons. Previous studies from cancer cell lines and clinical specimens attempted to correlate expression of Topo II with drug sensitivity. Mammalian cells, however, contain two isoforms of Topo II, termed Topo II alpha (subunit molecular weight, 170 kDa) and Topo II beta (subunit molecular weight, 180 kDa), both of which are sensitive to Topo II poisons. Studies of Topo II alpha in normal cells and tissues are limited, and few studies have begun to characterize the beta isoform. This study employed in situ immunohistochemical staining to characterize the tissue distribution of Topo II alpha in formalin-fixed, paraffin-embedded human tissues. A new antibody, confirmed by Western blot, specific to the beta isoform, was also used to characterize its distribution in non-neoplastic, formalin-fixed, paraffin-embedded human tissues and 33 cases of non-Hodgkin's lymphomas. Topo II alpha was identified in normal tissues with proliferating cells, especially in spermatocytes, germinal centers, and proliferative endometrium. Some terminally differentiated tissues, e.g., cerebral cortex, skeletal muscle, and nerve, showed no detectable Topo II alpha, whereas others, e.g., breast, salivary gland, and kidney, showed rare positive cells. In contrast, Topo II beta was present in all tissues, including fully differentiated tissues, e.g., cerebellum, myometrium, pancreas, as well as in tissues with cell turnover, e.g., endometrium, skin, and bowel mucosa. In non-Hodgkin's lymphomas, Topo II beta was uniformly present with no change in the intensity or staining pattern among the tumor subtypes. Topo II alpha may be distinguished from the beta isoform using immunohistochemical techniques, which permit precise localization of the enzyme in individual cells. Detection of this differential expression between the alpha and beta isoform of Topo II suggests distinct physiologic roles and might allow better therapeutic targeting for tumors.

Management of unstable angina: the role of noninvasive risk stratification

Many cardiologists rely primarily on catheterization to evaluate, and revascularization to treat, patients with unstable angina. In this era of managed care and cost containment, it is useful to determine whether some patients with unstable angina might benefit sufficiently from noninvasive testing and medical therapies. Several studies provide evidence that myocardial perfusion imaging is valuable for evaluating cardiac risk and thus determining the best candidates for medical treatment. Comparative studies indicate that myocardial perfusion imaging is superior to stress electrocardiography for assessing risk in patients with unstable angina.

Amrinone stimulation test: ability to predict improvement in left ventricular ejection fraction after coronary bypass surgery in patients with poor baseline left ventricular function

OBJECTIVES

This study sought to determine whether the response to amrinone in patients with severe baseline left ventricular dysfunction can predict improvement in left ventricular ejection fraction after coronary artery bypass graft surgery.

BACKGROUND

Previous studies have suggested that the inotropic response to dobutamine can identify viable myocardium in the setting of chronic coronary disease and left ventricular dysfunction. However, increased oxygen demand stimulated by dobutamine can lead to superimposition of ischemia on the hibernating state, potentially confounding interpretation of results. Amrinone is an inotropic agent that does not critically augment myocardial oxygen demand and may be useful for identification of hibernating myocardium in the chronically ischemic state.

METHODS

Forty-four consecutive patients with coronary artery disease and left ventricular ejection fraction < 40% referred for coronary artery bypass graft surgery underwent amrinone stimulation (1 mg/kg body weight). Left ventricular ejection fraction was determined before amrinone stimulation, 20 min after infusion and 21 days after bypass surgery.

RESULTS

Baseline ejection fraction was 28 +/- 7% (mean +/- SD). Ejection fraction increased to 35 +/- 5% after amrinone stimulation (p < 0.0001) and to 33 +/- 6% after bypass surgery (p < 0.0001). Postbypass ejection fraction was significantly correlated with postamrinone ejection fraction (r = 0.65, p < 0.0001). Furthermore, the change in ejection fraction from baseline to after bypass surgery was highly correlated with the change in ejection fraction after amrinone stimulation (r = 0.75, p < 0.0001). Of 13 patients with an increase in ejection fraction > or = 10% after amrinone, all 13 had an increase of at least 8% and 11 (85%) of 13 had an increase > or = 10% after bypass surgery. In contrast, of 31 patients with an increase in ejection fraction < 10% after amrinone, only 2 (6%) had an increase > or = 10% (p < 0.0001) and 28 (90%) of 31 had an increase < 5% after bypass surgery.

CONCLUSIONS

Augmentation of myocardial contraction by amrinone in patients with chronic coronary artery disease and severe baseline left ventricular dysfunction predicts improvement in left ventricular ejection fraction after coronary artery bypass graft surgery.

Prognostic value of myocardial perfusion imaging: state of the art and new developments

Although the prognostic value of myocardial perfusion imaging is now well established, new data have continued to expand its role in the management of patients. This review addresses the current state-of-the-art and new developments in the use of myocardial perfusion imaging for determining cardiac risk and integrating such information into patient care.

Reduction of Acute Low Back Injuries by Use of Back Supports

The objective of this study was to determine the effect of a change in back-support-use policy on the occurrence of work-related low back injuries among a large cohort of employees in the retail-trade home improvement industry. Working hours of exposure, back support use, and intensity of materials-lifting requirements were collected from 1989 through 1994. Records of injury-related claims were reviewed for all documented injuries to the lower back among members of the cohort during the same period. Over 101,000,000 working hours were recorded by nearly 36,000 employees; 2,152 employees reported an acute low back injury occurring during working hours as a first report of episode, with medical-physician diagnosis and acute/abrupt onset. Incidence density rates were calculated for persons wearing and not wearing the back support. Rate ratios and prevented fractions were evaluated. Before implementation of a company-wide back-support policy, the employees had a rate of acute low back injuries of 30.6 per million working hours. After implementation, this rate fell to 20.2 per million working hours, a significant reduction of 34.0%. This effect was seen in both genders, in younger workers and in those aged 55+, with low levels of lifting as well as high lifting intensities, and in persons with one to two years of employment with the company. The authors conclude that uniform mandatory implementation of a back-support-use policy significantly reduces the incidence of acute low back injuries incurred in the workplace.

Child pedestrian and bicyclist injuries: results of community surveillance and a case-control study

OBJECTIVES

To describe the dimensions of childhood pedestrian and bicyclist injuries in Long Beach, California, and to identify risk factors for these injuries.

POPULATION

Long Beach residents aged 0-14 years who were involved in an auto versus pedestrian or bicyclist incident that resulted in a hospital visit and/or police response, between 1 September 1988 and 31 August 1990.

METHODS

Cases were identified retrospectively using hospital charts, police records, and coroner's reports; demographic, clinical, and situational information were abstracted from the same. A nested case-control study was conducted to examine the street environments where children were injured, and to identify environmental risk factors at these case sites.

RESULTS

288 children comprised the sample population. Midblock dart-outs emerged as the single most common type of incident. Most incidents happened on residential streets, but the risk of injury was greatest on larger boulevards, and tended to cluster by region within the city. Adjusted odds ratios show that case sites had a larger proportion of traffic exceeding posted speed limits, and were also four times more likely to be near a convenience store, gas station, or fast food store than control sites.

CONCLUSIONS

The findings of this study suggest three possible routes for the prevention of childhood pedestrian and bicyclist injuries: education, law enforcement, and environmental modification.

Geographic and temporal patterns of recurrent intentional injury in south-central Los Angeles

To better understand geographic and temporal patterns of recurrent intentional injury, 285 consecutive trauma patients were evaluated prospectively. Fifteen were excluded because of immediate death or severe brain injury. The remaining 270 patients were interviewed. Of these, 59 (22%) had been treated in a hospital for a total of 75 previous episodes of intentional trauma (mean: 1.3 episodes/patient). In 66 of the 75 episodes, the patient recalled where treatment had been received (88%). Twenty-eight (42%) of the 66 episodes had been treated at King/Drew Medical Center (KDMC), 36 (55%) had been treated at a hospital within a 3-mile radius of KDMC, 48 (73%) within an 8-mile radius, and 63 (95%) within a 10-mile radius. Sixty-five percent of the episodes occurred 5 years or less prior to the current injury (range: 11 days to 30 years; mean: 4.9 years). Patients currently admitted for intentional injury were more likely to have had intentional injury previously than those with unintentional injury (27% versus 12%). Based on these findings, we conclude that intentional trauma patients in our community remain in a defined geographic region and that there is a definable high-risk period for recurrent intentional injury. These conclusions should enhance the development of a framework on which future violence prevention programs can be designed.

Human sequences homologous to the gene for the cochlear protein Ocp-II do not map to currently known non-syndromic hearing loss loci

The abundant and almost exclusive expression of OCP-II protein in the mammalian cochlea has fuelled speculation that mutations in the OCP2 gene may result in inherited forms of hearing impairment. We have identified several human sequences related to OCP2 and sublocalised three of these OCP2 related loci to 4q12-p14 or 4p16.2-pter, 5q15-q21.3 and 7p22-q22 by PCR. 2 YACs with sequence consistent with the chromosome 7 locus were also used for FISH analysis and hybridised to chromosome 7q11. Our data suggest that the cytogenetic localisations of these OCP2 related sequences do not correlate with the precise chromosomal positions of deafness loci so far identified.

The site of acute myocardial infarction is related to the coronary territory of transient defects on prior myocardial perfusion imaging

BACKGROUND

Prior studies have established the prognostic value of myocardial perfusion imaging. In particular, the presence and extent of transient defects have been shown to predict future cardiac events including acute myocardial infarction. However, the relationship between the location of the perfusion defect and the site of subsequent myocardial infarction remains unclear.

METHODS AND RESULTS

Review of prior records of consecutive patients admitted with acute myocardial infarction identified 34 patients whose prior myocardial perfusion imaging studies had demonstrated transient defects and no interval revascularization. The coronary artery territory of the transient defects was identified and related to the site of subsequent acute myocardial infarction. To reduce the potentially confounding effect of progression of coronary artery disease between the time of the myocardial perfusion imaging study and subsequent infarction, patients were divided into those less than 2 years and those 2 years or greater between imaging and infarction. Among patients with a transient defect and less than 2 years between infarction and imaging, 11 (79%) of 14 had a myocardial infarction in the same coronary territory as their prior transient defect (p < 0.0005). This association decreased to only five (25%) of 20 when the interval was 2 years or greater (difference not significant). Among 22 patients who had undergone prior coronary angiography, myocardial infarction occurred in the same coronary territory as the most severe angiographic stenosis in 12 (54%). The association was not related to the time interval between angiography and infarction.

CONCLUSIONS

There is a strong association between the coronary territory of transient defects on myocardial perfusion imaging and the site of subsequent myocardial infarction when the duration is less than 2 years. These observations support the concept that the hemodynamic significance of a coronary lesion is an important factor in the pathophysiology of acute myocardial infarction.

Skeletal muscle and cardiovascular adaptations to exercise conditioning in older coronary patients

BACKGROUND

Older coronary patients suffer from a low functional capacity and high rates of disability. Supervised exercise programs improve aerobic capacity in middle-aged coronary patients by improving both cardiac output and peripheral extraction of oxygen. Physiological adaptations to aerobic conditioning, however, have not been well studied in older coronary patients.

METHODS AND RESULTS

The effect of a 3-month and a 1-year program of intense aerobic exercise was studied in 60 older coronary patients (mean age, 68 +/- 5 years) beginning 8 +/- 5 weeks after myocardial infarction or coronary bypass surgery. Outcome measures included peak aerobic capacity, cardiac output, arterio-venous oxygen difference, hyperemic calf blood flow, and skeletal muscle fiber morphometry, oxidative enzyme activity, and capillarity. Training results were compared with a sedentary, age- and diagnosis-matched control group (n = 10). Peak aerobic capacity increased in the intervention group at 3 months and at 1 year by 16% and 20%, respectively (both P < .01). Peak exercise cardiac output, hyperemic calf blood flow, and vascular conductance were unaffected by the conditioning protocol. At 3 and 12 months, arteriovenous oxygen difference at peak exercise was increased in the exercise group but not in control subjects. Histochemical analysis of skeletal muscle documented a 34% increase in capillary density and a 23% increase in succinate dehydrogenase activity after 3 months of conditioning (both P < .02). At 12 months, individual fiber area increased by 29% compared with baseline (P < .01).

CONCLUSIONS

Older coronary patients successfully improve peak aerobic capacity after 3 and 12 months of supervised aerobic conditioning compared with control subjects. The mechanism of the increase in peak aerobic capacity is associated almost exclusively with peripheral skeletal muscle adaptations, with no discernible improvements in cardiac output or calf blood flow.

IL-6 acts on endothelial cells to preferentially increase their adherence for lymphocytes

Using a quantitative monolayer adhesion assay, the current report shows that treatment of human umbilical vein endothelial cells (HUVEC) with IL-6 increases their adhesiveness for blood lymphocytes, particularly CD4+ cells, but not for polymorphonuclear cells and monocytes. This effect, which was most pronounced when using low concentrations of the cytokine (0.1-1.0 U/ml) and a short incubation period (4h), was also apparent with microvascular endothelial cells and a hybrid endothelial cell line. Skin lesions from patients with mycosis fungoides contain high levels of IL-6, and blood lymphocytes from patients with this disorder also exhibited an enhanced adhesion to IL-6-treated HUVEC. The cytokine enhanced intercellular adhesion molecule-1 (ICAM-1) expression and induced the expression of vascular cell adhesion molecule-1 (VCAM-1) and E-selectin on endothelial cells. Antibody blocking studies demonstrated that the vascular adhesion molecules ICAM-1, VCAM-1 and E-selectin and the leucocyte integrin LFA-1 all contributed to lymphocyte binding to endothelium activated by IL-6. It is proposed that IL-6 may be involved in the recruitment of lymphocytes into non-lymphoid tissue.

Enhanced binding of lymphocytes from patients with multiple sclerosis to tumour necrosis factor-alpha (TNF-alpha)-treated endothelial monolayers: associations with clinical relapse and adhesion molecule expression

This study investigated the adherent properties and adhesion molecule expression of blood mononuclear cells (MNC) from a total of 84 patients with multiple sclerosis (MS). The MNC from MS patients were significantly more adherent than cells from normal healthy subjects to endothelial monolayers pretreated with 0.01 U/ml TNF-alpha (103% increase; P = 0.002), 0.1 U/ml TNF-alpha (80% increase; P < 0.01) and 1.0 U/ml TNF-alpha (41% increase; P < 0.02), and to endothelium pretreated with 10 U/ml IL-1 beta (44% increase; P < 0.05) and 100 U/ml interferon-gamma (IFN-gamma) (100% increase; P < 0.05). This augmented adhesion was a property of the lymphocytes, in particular CD4+ cells, and was inversely related to the time of onset of clinical relapse. The percentage of lymphocytes bearing the adhesion molecules CD49d, CD29 and CD62L was increased in MS blood, but the level of CD29 and CD62L expression was reduced. We infer that circulating lymphocytes in MS are predisposed to cross endothelial barriers at sites where inflammation has already commenced.

Ventilatory parameters in children during propofol anaesthesia: a comparison with halothane

PURPOSE

The purpose of this study was to compare the effects of propofol on ventilation with those of halothane.

METHODS

Respiration was studied in 20 spontaneously breathing children undergoing elective dental restoration randomized to receive either propofol (Group P) or halothane (Group H) anaesthesia. Data were recorded at different inspired concentrations of halothane (F1H) or propofol (RivP) during a washout of the anaesthetic agent. The F1H 2%, 1% and 0% corresponded to an end-tidal halothane concentration of 1.38 +/- 0.06%, 0.857 +/- 0.03% and 0.191 +/- 0.01% respectively. The RivP were 18, 15, 12, 9 and 0 mg.kg-1.hr-1. The inspiratory flow waveform, the CO2 waveform and the occluded inspiratory pressure waveform were recorded. The flow waveform was analyzed for minute ventilation (Vi), and tidal volume (VT), parameters of breath Timing [Total time (Ttot), Inspiratory time (Ti)] and parameters of breath Amplitude [mean inspiratory flow (VT/Ti)]. The slope of the initial 100 msec (dP/dt0.1) of an occluded inspiration, together with the occluded inspiratory time (Tiocc) and the ratio of the occluded to unoccluded inspiratory time (Tiocc/Ti) were obtained.

RESULTS

There were intergroup differences in the preemergence values of Ttot, dP/dt0.1 and Tiocc/Ti. In group P the Vi, VT and Ttot increased and PETCO2 decreased during a washout of propofol. The values of dP/dt0.1 in Group P at all RivP were half the values of those in Group H. The ratio Tiocc/Ti did not change in Group P and increased in Group H during a washout of halothane.

CONCLUSION

Propofol anaesthesia was associated with a decrease in Vi whereas during halothane anaesthesia, Vi did not change. Ventilation in Group P differed from Group H in parameters of both breath Drive and Timing.

Forensic implications of the variation in morphology of marginal serrations on the teeth of the great white shark

The teeth of the Great White Shark have been examined to ascertain whether there is any commonality in the arrangement or number of the marginal serrations (peaks) or, indeed, whether individual sharks have a unique pattern of shapes or size of the peaks. The teeth of the White Shark are characteristic in size and shape with serrations along almost the entire mesial and distal margins. This study has revealed no consistent pattern of size or arrangement of the marginal serrations that was sufficiently characteristic within an individual shark to serve as a reliable index of identification of a tooth as originating from that particular shark. Nonetheless, the serrations are sufficiently distinctive to enable the potential identification of an individual tooth as having been the cause of a particular bitemark.

Two-dimensional and dobutamine stress echocardiography in the preoperative assessment of patients with end-stage liver disease prior to orthotopic liver transplantation

Orthotopic liver transplantation is an established therapy for end-stage liver disease. This study evaluated the range of cardiovascular abnormalities in patients undergoing evaluation for orthotopic liver transplantation and determined the prognostic implications of abnormal echocardiographic features, including ischemia during dobutamine stress echocardiography, in predicting postoperative cardiac events. Two-dimensional echocardiography was performed in 190 patients for assessment of left ventricular function, valvular pathology, and pulmonary hypertension. Dobutamine stress echocardiography was performed in 165 patients for evaluation of inducible ischemia. Contrast echocardiography for detection of intrapulmonary shunting was performed in 125 patients at rest and in 99 during dobutamine stress. Left ventricular dysfunction, significant valvular regurgitation, and inducible ischemia were identified in <1O% of patients. Pulmonary hypertension, left ventricular hypertrophy and > or = moderate intrapulmonary shunting were present in 12%, 16%, and 26% of patients, respectively. Severe intrapulmonary shunting predicted death prior to transplantation (P=0.01). Of the 71 transplanted patients, major perioperative events included global left ventricular dysfunction in four patients and myocardial infarction in one patient with normal coronary arteries. No preoperative echocardiographic parameters, including ischemia on dobutamine echocardiography, predicted these perioperative events. No cardiac events related to obstructive coronary artery disease occurred in the 154 patients without ischemia on dobutamine stress echocardiography. The majority of patients with end-stage liver disease, including those with alcoholic cirrhosis, have normal cardiac function on two-dimensional echocardiography. Severe intrapulmonary shunting portends a poor prognosis in patients awaiting transplantation. A negative dobutamine stress echocardiogram appears useful in excluding patients at risk for perioperative cardiac events related to obstructive coronary artery disease.

bcl-2 is down-regulated in atypical endometrial hyperplasia and adenocarcinoma

The bcl-2 protein, which protects cells from apoptosis, is normally expressed in a number of adult tissues. Dysregulated bcl-2 expression, secondary to (14;18) chromosomal translocation, seems to promote the development of follicular lymphomas, and recent findings of bcl-2 protein in several solid tumors suggest that it might contribute to the genesis of many other neoplasms. bcl-2 is also highly expressed in normal proliferative endometrium and markedly down-regulated in secretory endometrium, which suggests that its expression is estrogen regulated. Because the development of most endometrial carcinomas is associated with hyperestrogenic states, we began the investigation of the role of bcl-2 in endometrial carcinogenesis by immunohistochemically quantifying its expression in proliferative, hyperplastic, atypically hyperplastic, and carcinomatous endometrium. The results of this study show that bcl-2 is relatively highly expressed in proliferative (n = 11) and hyperplastic (n = 18) endometrium, with respective mean staining scores of 3.59 and 3.47 (scale, 0-4), but is significantly (P < 0.001) down-regulated in atypical hyperplasia (n = 11; score, 0.82), and adenocarcinoma (n = 34; score, 0.86). bcl-2 expression did not correlate with stage, grade, estrogen-receptor, or progesterone-receptor expression. Polymerase chain reaction analyses of DNA isolated from several endometrial carcinomas were negative for (14;18) translocation involving the bcl-2 gene. Thus, bcl-2 apparently plays no role in the progression of atypical hyperplasia to carcinoma or in the development of high-grade or advanced-stage endometrial carcinoma. These results, however, do not rule out the involvement of bcl-2 in very early, preatypical hyperplasia phases of endometrial carcinogenesis. Finally, the marked difference in bcl-2 expression in hyperplastic and atypically hyperplastic glands might prove to be diagnostically useful in the often difficult distinction of these entities.

Development and validation of a Bayesian model for perioperative cardiac risk assessment in a cohort of 1,081 vascular surgical candidates

OBJECTIVES

This study sought to develop and validate a Bayesian risk prediction model for vascular surgery candidates.

BACKGROUND

Patients who require surgical treatment of peripheral vascular disease are at increased risk of perioperative cardiac morbidity and mortality. Existing prediction models tend to underestimate risk in vascular surgery candidates.

METHODS

The cohort comprised 1,081 consecutive vascular surgery candidates at five medical centers. Of these, 567 patients from two centers ("training" set) were used to develop the model, and 514 patients from three centers were used to validate it ("validation" set). Risk scores were developed using logistic regression for clinical variables: advanced age (>70 years), angina, history of myocardial infarction, diabetes mellitus, history of congestive heart failure and prior coronary revascularization. A second model was developed from dipyridamole-thallium predictors of myocardial infarction (i.e., fixed and reversible myocardial defects and ST changes). Model performance was assessed by comparing observed event rates with risk estimates and by performing receiver-operating characteristic curve (ROC) analysis.

RESULTS

The postoperative cardiac event rate was 8% for both sets. Prognostic accuracy (i.e., ROC area) was 74 +/- 3% (mean +/- SD) for the clinical and 81 +/- 3% for the clinical and dipyridamole-thallium models. Among the validation sets, areas were 74 +/- 9%, 72 +/- 7% and 76 +/- 5% for each center. Observed and estimated rates were comparable for both sets. By the clinical model, the observed rates were 3%, 8% and 18% for patients classified as low, moderate and high risk by clinical factors (p<0.0001). The addition of dipyridamole-thallium data reclassified >80% of the moderate risk patients into low (3%) and high (19%) risk categories (p<0.0001) but provided no stratification for patients classified as low or high risk according to the clinical model.

CONCLUSIONS

Simple clinical markers, weighted according to prognostic impact, will reliably stratify risk in vascular surgery candidates referred for dipyridamole-thallium testing, thus obviating the need for the more expensive testing. Our prediction model retains its prognostic accuracy when applied to the validation sets and can reliably estimate risk in this group.

The accumulation of multiple genetic abnormalities in individual tumor cells in human breast cancers: clinical prognostic implications

PURPOSE

Human solid tumors undergo multiple genetic evolutionary changes as they evolve from the normal state to advanced stages of malignancy. This study characterizes the degree of advancement of primary human breast cancers in their genetic evolutionary pathways, and determines if this is of clinical significance.

MATERIALS AND METHODS

Correlated cell-by-cell measurements of cell DNA content, HER-2/neu protein content per cell, and H-ras protein content per cell were obtained by means of multiparameter flow cytometry on primary tumors from 95 patients with clinically localized breast cancer. Laboratory findings were correlated with subsequent clinical course in 91 of these patients.

RESULTS

Multiple genetic abnormalities were found to accumulate in individual cells in primary human breast cancers. Almost all tumors contained subsets of cells with one, two, or three abnormalities per cell in various combinations. After a median follow-up time of 32 months, 11 of 13 patients with early recurrence had primary tumors in which more than 5% of cells were hypertetraploid, overexpressed HER-2/neu protein, and overexpressed H-ras protein (triple-positive cells). The duration of disease-free survival among patients with primary tumors that contained triple-positive cells was significantly shorter than for patients whose tumors did not contain triple-positive cells. The presence of subpopulations of cells with maximums of only one abnormality per cell or only two abnormalities per cell, in any combination, was of no prognostic significance. Among patients whose nodal status was known, 12 had recurrent disease, and all had positive axillary nodes. Among 36 patients known to have negative axillary nodes, no recurrence has been reported to date.

CONCLUSIONS

The number of genetic abnormalities that accumulate in individual cells in primary breast cancers reflects the degree of advancement of a tumor in its genetic evolutionary sequence, and provides useful clinical prognostic information. Because follow-up duration is still relatively short, and because disease in node-negative patients tends to recur later than in node-positive patients, it is still too early to know if three measurements per cell will be sufficient to improve prognosis in node-negative disease.

Pattern of ventilation during halothane anaesthesia in infants less than two months of age

PURPOSE

To examine the breathing pattern of infants aged less than two months in order to understand better the effect of halothane on ventilation in infants.

METHODS

The inspiratory flow waveform, the CO2 waveform and occluded inspiratory pressure waveform were recorded at different inspired concentrations of halothane using a washout of halothane in two groups of infants undergoing elective herniorrhaphy. Data were analyzed for minute ventilation (Vi) and tidal volume (VT), parameters of timing of the breath [Total time (Ttot), Inspiratory time (Ti), and the ratio of the occluded to unoccluded inspiratory time (TiOCC/Ti)], parameters of Amplitude of the neural output [mean inspiratory flow (VT/Ti)] and parameters of the Shape of the inspiratory breath profile [the inspiratory flow centroid (Ci/Ti), the inspiratory duty cycle (Ti/Ttot)]. The airway was occluded at end expiration and the slope of the initial 100 msec of occlusion (dP/dt) together with the maximal negative pressure (PMAX) and occluded inspiratory time (TiOCC) were obtained. We studied ten infants < 48 wk post-conceptional age (PCA) and ten infants > 48 wk. PCA Flow (V), pressure (Pao) and carbon dioxide tension (PCO2) were recorded at three concentrations of inspired halothane (FiH): 0%, 1% and 2% which corresponded to an end-tidal halothane concentration of about 0.2%, 0.8% and 1.2% respectively.

RESULTS

In both groups Vi, VT and VT/Ti decreased whereas dP/dt, did not, suggesting that the respiratory pump was impaired. The parameters of breath Shape did not change. Importantly the parameters of Timing showed different tendencies. In infants > 48 wk PCA TiOCC/Ti decreased. In infants < 48 wk PCA, TiOCC/Ti did not change.

CONCLUSIONS

The different response in the timing parameter TiOCC/Ti is consistent with a different effect of halothane on parameters of ventilatory timing in infants < 48 wk PCA and this may represent a maturational effect.

The effects of meal schedule and quantity on problematic behavior

We present 2 case examples that illustrate the effects of meal schedule and quantity on displays of problematic behavior. In the first example, self-injury displayed by a toddler with severe developmental delays was maintained by parent attention, but only when he was satiated for food. When he was food deprived, self-injury decreased but did not appear to be differentiated across low or high social conditions. In the second example, crying and self-injury displayed by an elementary-aged girl with severe disabilities were correlated: Both behaviors were associated with food quantity, and neither behavior was responsive to social stimuli. These results replicate and extend previous findings demonstrating that meal schedule or food quantity can affect problematic behavior. In the present studies, brief functional analyses of aberrant behavior provided useful information for interpreting distinct patterns of behavior displayed by each child. We discuss these results in terms of the concept of establishing operations.

Choice-making treatment of young children's severe behavior problems

The choice-making behavior of 5 young children with developmental disabilities who engaged in aberrant behavior was studied within a concurrent operants framework. Experimental analyses were conducted to identify reinforcers that maintained aberrant behavior, and functional communication training packages were implemented to teach the participants to gain reinforcement using mands. Next, a choice-making analysis, in which the participants chose one of two responses (either a mand or an alternative neutral response) to obtain different durations and qualities of reinforcement, was conducted. Finally, treatment packages involving choice making via manding were implemented to decrease inappropriate behavior and to increase mands. The results extended previous applications of choice making to severe behavior disorders and across behaviors maintained by positive and negative reinforcement.

Gender differences in parenting a child with cancer

This study of 124 parents of children diagnosed with cancer investigates parents' perceptions of their role in the illness situation. The study found that mothers and fathers differ in their experience of and response to parenting a child with cancer. These differences appear to reflect traditional parenting roles characterized by a gender-based division of labor. Sex-role socialization theory is discussed as an explanatory model of the parenting experience. Practice recommendations are offered to medical social workers and other health care professionals concerned about the long term psychosocial adjustment of parents with chronically ill children.

Linkage studies of non-syndromic recessive deafness (NSRD) in a family originating from the Mirpur region of Pakistan maps DFNB1 centromeric to D13S175

Autosomal recessive non-syndromal hearing impairment (NSRD) is genetically heterogeneous. Five loci have been identified to date which map to chromosomes 13 (DFNB1), 11 (DFNB2), 17 (DFNB3), 7 (DFNB4) and 14 (DFBN5). We report definite linkage of NSRD to the locus DFNB1 in a single family of 27 families studied of Pakistani origin. Haplotype analysis of markers in the pericentromeric region of chromosome 13q revealed a recombination event which maps DFNB1 proximal to the marker D13S175 and in the vicinity of D13S143.

Quantitative forensic evaluation of bite marks with the aid of a shape analysis computer program: Part 1; The development of "SCIP" and the similarity index

Bite marks left on human tissue and bitten material have become an important aspect of scientific evidence used for the conviction or acquittal of a suspect. Expert opinion has often been based on subjective comparisons rather than any objective metrical analysis and many experts will agree that there is a need to employ additional comparative tests to achieve unbiased objectivity in their investigation. In this study, an interactive shape analysis computer program ("SCIP"-Shape Comparison Interactive Program) has been employed in an attempt to derive experimentally a quantitative comparison, in the form of a Similarity Index (S.I.), between the "offender's" teeth and the bite marks produced on a standard flat wax form. The S.I. values obtained using "SCIP" were evaluated in a variety of experimental bite mark situations. It was found that in no case could the S.I. values produced by comparison of the bite mark with the dental casts from non-perpetrators be confused with the much lower S.I. from comparison of the bite mark with the dental cast of the perpetrator. The use of the Similarity Index derived using the "SCIP" program is recommended as a simple, accurate and objective means of comparing bite marks in suitable forensic cases.

A bitemark and a fracture?

The kidnap and brutal murder of the eleven year-old daughter of a fire brigade officer in the town of Wassenaar in the Netherlands on September 29, 1980, resulted in the first ever appearance of a forensic odontologist as an expert witness in the history of Dutch law. This previously unpublished case is now reviewed for its historic significance, and also because it presents an interesting problem of interpretation of odontological evidence relevant to the identification of the offender, and raises issues concerning proper procedures for the utilisation of expertise in forensic odontology.

Quantitative forensic evaluation of bite marks with the aid of a shape analysis computer program: Part 2; "SCIP" and bite marks in skin and foodstuffs

In a previous paper 1, we have shown that the use of an interactive shape analysis computer program ("SCIP") and the derivation of a quantitative Similarity Index 1 greatly facilitated the comparison of experimental flat wax bite marks with the dentition of various 'suspects' and the identification of the agent producing the bite. In this study, "SCIP" was employed in an attempt to quantify the comparison, in the form of the Similarity Index (S.I.), between the "offender's" teeth and the bite marks produced on foodstuffs and on human skin, under experimental conditions. The use of "SCIP" and the S.I. is recommended as a routine means of eliminating suspects in bite mark cases. If a reasonable number of reference points have been registered in the bitten material and particularly if the perpetrator has any unusual features in the anterior dentition, the matching of the bite mark with the actual offender is a possibility with this method.

Differences in oxidative response of subpopulations of neutrophils from healthy subjects and patients with rheumatoid arthritis

OBJECTIVES

To determine whether blood neutrophils from healthy individuals and blood and synovial fluid neutrophils from patients with rheumatoid arthritis (RA) responded differently to priming agonists and stimuli of the oxidative burst and, if so, whether this was a property of a subpopulation of neutrophils.

METHODS

Continuous flow electrophoresis was used to separate neutrophils into subpopulations based upon quantitative differences in net negative surface charge. The generation of superoxide anion (O2-) was used as a measure of oxidative activity using 10(-7) mol/l N-formyl-methionylleucyl-phenylalanine (FMLP) as the stimulating agonist and 10(-8) mol/l platelet activating factor (PAF) as the priming agent.

RESULTS

The production of O2- by blood and synovial fluid neutrophils from RA patients in response to FMLP was greater than that observed with control blood neutrophils (p < 0.001). Priming of normal blood neutrophils with PAF increased their FMLP induced oxidative burst (p < 0.001), but PAF treatment had no effect on rheumatoid neutrophils. Neutrophils from synovial fluid of RA patients were less electronegative than paired blood samples and exposure of blood neutrophils to FMLP but not PAF reduced their surface charge. Continuous flow electrophoresis isolated three neutrophil subpopulations: cells of least surface electronegativity were ascribed to pool P1 and cells of greatest surface electro-negativity to P3. Normal blood neutrophils from P3, but not P1, showed increased oxidative activity after PAF priming (twofold increase; p < 0.01), whereas the responsiveness of rheumatoid blood and synovial fluid neutrophils from P1 and P3 was not modified by PAF treatment under the same conditions.

CONCLUSION

It is suggested that most of the circulating neutrophils in RA are already in a state of readiness to generate O2- upon activation by an inflammatory stimulus. This is in contrast to normal blood neutrophils, which have both responsive and non-responsive subpopulations with respect to priming agonists.

Blood monocytes in rheumatoid arthritis are highly adherent to cultured endothelium

Monocytes from 17 patients with rheumatoid arthritis (RA) were more adherent than monocytes from 17 control patients to monolayers of pig aortic endothelium irrespective of whether sera was included (median 27-34% increase; p = 0.002) or omitted (median 27% increase; p = 0.022) from the culture media. When human umbilical vein endothelial cells were used as the adherence substrate, rheumatoid monocytes from an additional 21 patients demonstrated a median 31% (p = 0.004) and 20% increase (p = 0.004) in adhesion when compared with monocytes from 21 normal healthy subjects in the absence and presence of autologous sera, respectively. Activation of control monocytes with muramyl dipeptide or treatment with RA sera increased their attachment to endothelium (mean 34 +/- 14% increase; p < 0.001). The expression of the adhesion molecules CD11b (p < 0.005), CD18 (p < 0.005), CD62L (p = 0.01) was enhanced on rheumatoid monocytes, but antibody-blocking studies suggested that CD18 and CD62L were not responsible for the augmented binding of the rheumatoid cells. A subpopulation of rheumatoid monocytes possessed a very low net negative surface charge, a property that favours binding to vessel walls. We propose that many rheumatoid monocytes are predisposed for sheer-resistant adhesion to vascular endothelium.

Accuracy of quantitation of aortic stenosis using femoral arterial recordings corrected for both temporal delay and systolic amplification

Our study demonstrates the feasibility of substituting FA recordings, corrected for both temporal delay and systolic amplification, for central aortic recordings in assessing aortic valve stenosis. This method is accurate in estimating the transaortic valve gradient, the calculated valve area, and the calculated valve resistance, and obviates the risks and costs of 2 FA punctures.