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Biomedical subjects

Steven M Banks

Publications and source records attributed to Steven M Banks.

16 recordsLinked to original sources
PubMed2004

Lethality during continuous anthrax lethal toxin infusion is associated with circulatory shock but not inflammatory cytokine or nitric oxide release in rats.

Although circulatory shock related to lethal toxin (LeTx) may play a primary role in lethality due to Bacillus anthracis infection, its mechanisms are unclear. We investigated whether LeTx-induced shock is associated with inflammatory cytokine and nitric oxide (NO) release. Sprague-Dawley rats with central venous and arterial catheters received 24-h infusions of LeTx (lethal factor 100 microg/kg; protective antigen 200 microg/kg) that produced death beginning at 9 h and a 7-day mortality rate of 53%. By 9 h, mean arterial blood pressure, heart rate, pH, and base excess were decreased and lactate and hemoglobin levels were increased in LeTx nonsurvivors compared with LeTx survivors and controls (diluent only) (P < or = 0.05 for each comparing the 3 groups). Despite these changes, arterial oxygen and circulating leukocytes and platelets were not decreased and TNF-alpha, IL-beta, IL-6, and IL-10 levels were not increased comparing either LeTx nonsurvivors or survivors to controls. Nitrate/nitrite levels and tissue histology also did not differ comparing LeTx animals and controls. In additional experiments, although 24-h infusions of LeTx and Escherichia coli LPS produced similar mortality rates (54 and 56%, respectively) and times to death (13.2 +/- 0.8 vs. 11.0 +/- 1.7 h, respectively) compared with controls, only LPS reduced circulating leukocytes, platelets, and IL-2 levels and increased TNF-alpha, IL-1 alpha and -1 beta, IL-6, IL-10, interferon-gamma, granulocyte macrophage-colony stimulating factor, RANTES, migratory inhibitory protein-1 alpha, -2, and -3, and monocyte chemotactic protein-1, as well as nitrate/nitrite levels (all P < or = 0.05 for the effects of LPS). Thus, in contrast to LPS, excessive inflammatory cytokine and NO release does not appear to contribute to the circulatory shock and lethality occurring with LeTx in this at model. Although therapies to modulate these host mediators may be applicable fo shock caused by LPS or other bacterial toxins, they may not with LeTx.

Animals↗
PubMed2003

TGF-beta1 increases microbial clearance but worsens lung injury during Escherichia coli pneumonia in rats.

We investigated the effects of either intravenous (IV) or intrabronchial (IB) treatment with transforming growth factor beta1 (TGF-beta1) during bacterial pneumonia in rats. Immediately following IB Escherichia coli inoculation (T0), animals (n=270) were randomized to receive a single treatment with human recombinant TGF-beta1 either via IV or IB, or via both IV and IB routes, or to receive placebo (human serum albumin, HSA) only. Blood and lung analysis was done at 6 and 168 h after E. coli inoculation. Other animals (n=40) were administered IV TGF-beta1 or HSA at T0 and 6, 12 and 24 h after E. coli inoculation to investigate the effects of multiple treatments also on survival rates alone. All animals received ceftriaxone daily. Route of administration did not influence TGF-beta1 (p=ns for the effect of TGF-beta1 comparing IV vs IB routes) and we averaged over this variable in analysis. The relative risk of death (mean +/- sem) was not altered by either single treatments administered at T0 (-0.18 +/- 0.25, p=0.47) or multiple treatments (0.40 +/- 0.50, p=0.66) of TGF-beta1. Single treatment with TGF-beta1 first decreased and then increased vascular leukocytes at 6 and 168 h, respectively, but increased alveolar leukocytes at both time points (p=0.02 comparing the differing effects of TGF-beta1 on vascular and alveolar leukocytes at 6 and 168 h). Although TGF-beta1 decreased blood and lung bacteria counts at 6 and 168 h, it also increased serum tumor necrosis factor levels and lung injury scores at these time points (p<0.05 for the effects of TGF-beta1 on each parameter at 6 and 168 h together). Thus, while increases in lung leukocyte recruitment with TGF-beta1 were associated with improved microbial clearance in this rat model of pneumonia, worsened lung injury may have negated these beneficial host defense effects, and overall survival was not significantly improved. Despite these harmful effects, additional studies may be warranted to better define the influence of exogenous TGF-beta1 on host defense during acute bacterial infections.

Animals↗
PubMed2003

Inpatient hospital care for work-related injuries and illnesses.

BACKGROUND: The aim of this study was to compile nationally representative statistics describing inpatient hospital care for patients with work-related injuries and illnesses covered under workers' compensation (WC) insurance in the United States. METHODS: Three years of data (1997-1999) from the Nationwide Inpatient Sample (NIS) were used to describe WC inpatient stays with respect to patient and hospital characteristics, principal diagnoses, number and type of procedures provided, total charges, length of stay, and time from admission to administering of the principal procedure. RESULTS: Approximately 209,139 WC hospitalizations occurred annually, representing 0.62% of all inpatient admissions. The average total charge per WC hospitalization was 14,966 dollars. After adjusting for the type of diagnosis and other factors, WC hospital care was found to involve 13-24% more procedures, have a slightly longer (4%) length of stay, and take 23-54% less time from admission to the principal procedure than inpatient care for comparable diagnoses paid by other sources. Inpatient care for disc and spinal disorders paid by WC had 16% higher charges than similar non-WC cases. Three-year trends showed a steady decline in the number of WC hospitalizations between 1997 and 1999 but a sharp 16% rise in total charges per WC stay. CONCLUSIONS: This research provides an initial foundation for understanding the extent and nature of hospitalized care for injured workers in the US and identifying significant trends in the delivery of care.

Adolescent↗
PubMed2003

Elevated risk of arrest for Veteran's Administration behavioral health service recipients in four Florida counties.

This paper examines the relative contribution of mental and substance abuse disorders to criminal justice involvement by examining the relative risk of arrest for three groups of adult male recipients of VA behavioral health care services. These groups include men served for both substance abuse and mental health, for only substance abuse, and for only mental health. The relative risk of multiple offences is compared to relative risk of a single offense for each group. Results indicated that relative risk of multiple arrests for the dual diagnosis group is substantially greater than for either of the single diagnosis groups, and greater than the relative risk for recipients of nonbehavioral health services. Relative risk of arrest for recipients of only mental health services is no different than the relative risk for other veterans living in the region under examination.

Adult↗
PubMed2003

Protection with antibody to tumor necrosis factor differs with similarly lethal Escherichia coli versus Staphylococcus aureus pneumonia in rats.

BACKGROUND: Differing factors may alter the effects of antibody to tumor necrosis factor (TNF) in infection and sepsis. The authors tested whether bacteria type or treatment route alters antibody to TNF in a rat model of bacterial pneumonia. METHODS: Rats (n = 231) received similarly lethal doses of either intratracheal Escherichia coli or Staphylococcus aureus followed by treatment with either intratracheal or intraperitoneal antibody to TNF or control serum. Animals received antibiotics (cefotiam daily dose, 100 mg/kg) starting 4 h after inoculation and were studied for up to 96 h. RESULTS: Compared with S. aureus, E. coli increased serum TNF and interleukin-6 concentrations, lung lavage TNF concentrations, neutrophil counts, and alveolar-to-arterial oxygen gradients and decreased circulating neutrophils and lymphocytes (P > or = 0.05 for all). Compared with controls, with both bacteria, except for lung lavage TNF concentrations (which decreased with intratracheal but not with intraperitoneal antibody to TNF), treatment route did not alter the effects of antibody to TNF on any parameter (P = not significant for all). Antibody to TNF reduced mortality rates (relative risk of death +/- SEM) with both E. coli (-1.6 +/- 0.6; P = 0.006) and S. aureus (-0.5 +/- 0.04; P = 0.185), but these reductions were greater with E. coli than with S. aureus in a trend approaching statistical significance (P = 0.09). Compared with controls, similarly (P = not significant) with both bacteria, antibody to TNF decreased lung lavage and tissue bacteria concentrations (both P < 0.05) and serum TNF concentration (P < 0.09) and increased circulating neutrophils and lymphocytes (both P < or = 0.01). Compared with S. aureus, with E. coli antibody to TNF decreased alveolar-to-arterial oxygen gradients (P = 0.04) and increased serum interleukin-6 concentrations (P = 0.003). CONCLUSION: Antibody to TNF improved host defense and survival rates with both lethal E. coli and S. aureus pneumonia, but protection was greater with E. coli, where TNF concentrations were higher than with S. aureus. The efficacy of antiinflammatory agents in sepsis may be altered by bacteria type.

Administration, Inhalation↗
PubMed2003

Sympathetic blockade in a canine model of gram-negative bacterial peritonitis.

We investigated, in a well-established canine model of human sepsis, the effects of two different techniques of sympathetic blockade during bacterial peritonitis on pain relief, hemodynamics, and survival rate. Twenty-two purpose-bred beagles (12-28 months old, weighing 10-12 kg) were studied. Fourteen animals received an epidural infusion of bupivicaine and morphine, and the other eight received either a celiac plexus block (n = 4) or a sham block (n = 4). Eighteen of the 22 animals received an intraperitoneal challenge of Escherichia coli (1-10 x 10(9) CFU kg(-1) body weight). At comparable doses of intraperitoneal-implanted E. coli (2.5-5 x 10(9) CFU kg(-1) body weight), the addition of sympathetic blockade produced a synergistic decrease in survival times (P = 0.002) and mean left ventricular ejection fraction (P = 0.008), and increase in creatinine levels (P = 0.02). There was also a significant increase in tumor necrosis factor (TNF) levels (P = 0.004) and decrease in blood endotoxin clearance (P = 0.006) associated with sympathetic blockade during sepsis. The celiac plexus-blocked animals had no improvement in pain scores, and subjectively looked clinically worse than animals with sepsis without a celiac plexus block. In contrast, the epidural block was effective in blocking the pain and discomfort associated with low lethality doses of intraperitoneal bacteria reflected by no increase in pain scores compared with animals not receiving bacterial challenge. This study shows that during severe bacterial peritonitis, maintenance of sympathetic tone irrespective of pain relief provided is necessary for clearance of bacterial toxins, control of proinflammatory mediator release, hemodynamic stability, and survival.

Animals↗
PubMed2003

Utility of the Time-Line Follow-Back to assess substance use among homeless adults.

Assessing substance use of homeless persons is a critical task. This study examines the test-retest reliability, concurrent validity, and sensitivity to change of the Time-Line Follow-Back interview, a calendar instrument used to assess days and quantities of alcohol use and days of illicit drug use, in the multisite Collaborative Program to Prevent Homelessness (CPPH). The Time-Line Follow-Back was reliable for assessing use during the past month and the recent 6 months. Results from the Time-Line Follow-Back were correlated with other self-reports of use, with research diagnoses of substance use disorder, and with clinician ratings of severity of substance abuse. The Time-Line Follow-Back detected changes in clients with severe mental illness and in those with less severe psychiatric problems.

Adult↗
PubMed2002

Risk and the efficacy of antiinflammatory agents: retrospective and confirmatory studies of sepsis.

We investigated whether a relationship between risk of death and treatment effect could explain the disparate results between the preclinical and clinical sepsis trials of antiinflammatory agents over the last decade. A metaregression analysis of cited preclinical studies showed that the treatment effects of these agents were highly dependent on risk of death (p = 0.0001) and that animals were studied at significantly higher control mortality rates than humans (median [25th-75th quartile], 88% [79-96%] versus 39% [32-42%], p = 0.0001). An analysis of the clinical trials showed that antiinflammatory agents were also significantly more efficacious in septic patients with higher risk of death (p = 0.002) and were harmful in those with low risk. To test this relationship prospectively, we studied antiinflammatory agents in models employing differing doses of bacterial challenge to produce the full range of risk of death. We found that the efficacy of these agents, although very beneficial at high control mortality rates, was much reduced (p = 0.0001) and similar to those in human trials at moderate control mortality rates (i.e., 30 to 40%). The efficacy of antiinflammatory agents during sepsis is dependent on the risk of death, an observation that explains the apparent contradiction between preclinical and clinical trial results. Accounting for this relationship may be necessary for the safe and effective development of antiinflammatory therapies for sepsis.

Adult↗
PubMed2002

Self-reported lifetime psychiatric hospitalization histories of jail detainees with mental disorders: comparison with a non-incarcerated national sample.

Lack of access to hospitalization is an often-cited risk factor for incarceration among persons with severe mental illness. This proposition is examined by comparing self-reports of lifetime psychiatric hospitalization histories of mentally ill jail inmates with data from a national sample of non-incarcerated mentally ill. Roughly 52% of mentally ill jail detainees reported at least one psychiatric hospitalization, a rate nearly three times that of the comparison group. The data call into question the notion that mentally ill jail inmates have reduced access to psychiatric inpatient treatment, without addressing the adequacy of the treatment received. Longitudinal studies are needed to explore temporal relationships to better understand the relationship between mental health treatment and criminal justice involvement.

Adult↗
PubMed2002

Office-based medical care for work-related conditions: findings from the National Ambulatory Medical Care Survey, 1997-1998.

Data from the 1997 and 1998 National Ambulatory Medical Care Surveys were analyzed to describe nationally representative patterns of office-based ambulatory medical care for work-related injuries and illnesses. Key dimensions of care included patient demographics, diagnoses, utilization of services, provider and payer information, and characteristics of the clinical setting in which care was delivered. Multivariate analyses revealed that compared to visits for nonwork related conditions, ambulatory care visits for work-related conditions are more likely to involve x-rays, injury prevention counseling, and physiotherapy. Surgical procedures, mental health counseling, prescription drug medication, and the taking of blood pressure were found to be relatively less common. Additionally, authorization for care was required considerably more often at visits for work-related conditions, and the provider for patients with work-related conditions was less likely to be the patient's regular primary care physician.

Ambulatory Care↗
PubMed2002

Mortality of mental health service recipients in Vermont and Oklahoma.

The authors compared statewide mortality rates for people with severe mental illness who were served in public mental health systems of care in Vermont and Oklahoma. In both states, mortality rates for younger service recipients, but not for older recipients, were significantly higher than those for the general population. In interpreting cross-region comparisons, several possible causes of variation, including differences in caseload composition and causes outside the control of the public mental health authority, must be considered.

Adolescent↗