Impact of azole antifungal treatment on outcome in acute invasive fungal rhinosinusitis with orbitocranial involvement: a surgical perspective

PURPOSE

To provide real-life data on azole treatment outcomes and the role of surgery in the current management of invasive fungal rhinosinusitis complicated by orbitocranial fungal infection (OCFI).

METHODS

Data was collected retrospectively from a chart review from four participating centers and a systematic literature review. The study group included patients with OCFI treated with azole antifungals. The control cases were treated with other antifungal agents. The cranial and orbital involvement degree was staged based on the imaging. The extent of the surgical resection was also classified to allow for inter-group comparison.

RESULTS

There were 125 patients in the azole-treated group and 153 in the control group. Among the patients with OCFI cranial extension, 23% were operated on in the azole-treated group and 18% in the control group. However, meninges and brain resection were performed only in the controls (11% of patients) and never in the azole antifungals group. Orbital involvement required surgery in 26% of azole-treated cases and 39% of controls. Despite a more aggressive cranial involvement, azole-treated patients' mortality was significantly lower than in controls, with an OCFI-specific mortality rate of 21% vs. 52%. A similar, though not statistically significant, trend was found for the extent of the orbital disease and surgery.

CONCLUSION

Despite less aggressive surgical intervention for cranial involvement, OCFI patients treated with azoles had a higher survival rate. This finding suggests we may improve morbidity with a more conservative surgical approach in conjunction with azole treatment. The same trend is emerging for orbital involvement.

Influence of intragenic CCL3 haplotypes and CCL3L copy number in HIV-1 infection in a sub-Saharan African population

Two CCL3 haplotypes (HapA1 and Hap-A3) and two polymorphic positions shared by the haplotypes (Hap-2SNP) were investigated together with CCL3L copy number (CN), for their role in HIV-1 disease. Hap-A1 was associated with protection from in utero HIV-1 infection: exposed-uninfected infants had higher representation of WT/Hap-A1 than infected infants (excluding intrapartum-infected infants), which maintained significance post maternal Nevirapine (mNVP) and viral load (MVL) correction (P=0.04; OR=0.33). Mother-infant pair analyses showed the protective effect of Hap-A1 is dependent on its presence in the infant. Hap-A3 was associated with increased intrapartum transmission: WT/Hap-A3 was increased in intrapartum vs. non-transmitting mothers, and remained significant post mNVP and MVL correction (P=0.02; OR=3.50). This deleterious effect of Hap-A3 seemed dependent on its presence in the mother. Hap-2SNP was associated with lower CD4 count in the non-transmitting mothers (P=0.03). CCL3 Hap-A1 was associated with high CCL3L CN in total (P=0.001) and exposed-uninfected infants (P=0.006); the effect was not additive, however having either Hap-A1 or high CCL3L CN was more significantly (P=0.0008) associated with protection from in utero infection than Hap-A1 (P=0.028) or high CCL3L CN (P=0.002) alone. Linkage disequilibrium between Hap-A1 and high CCL3L CN appears unlikely given that a Nigerian population showed an opposite relationship.

Role of the laboratory in ensuring global access to ARV treatment for HIV-infected children: consensus statement on the performance of laboratory assays for early infant diagnosis

A two day meeting hosted by the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) was held in May 2006 in Entebbe, Uganda to review the laboratory performance of virologic molecular methods, particularly the Roche Amplicor DNA PCR version 1.5 assay, in the diagnosis of HIV-1 infection in infants. The meeting was attended by approximately 60 participants from 17 countries. Data on the performance and limitations of the HIV-1 DNA PCR assay from 9 African countries with high-burdens of HIV/AIDS were shared with respect to different settings and HIV- subtypes. A consensus statement on the use of the assay for early infant diagnosis was developed and areas of needed operational research were identified. In addition, consensus was reached on the usefulness of dried blood spot (DBS) specimens in childhood as a means for ensuring greater accessibility to serologic and virologic HIV testing for the paediatric population.

Revised guidelines for diagnosis of perinatal HIV-1 infection in South Africa

No abstract available.

A comparison of high versus low dose recombinant human erythropoietin versus blood transfusion in the management of anaemia of prematurity in a developing country

The purpose of this study was to evaluate the effectiveness of early treatment with erythropoietin (EPO) in two different treatment regimes (high vs. low dose) in comparison to the conventional treatment of packed red blood cell (PRBC) transfusions in the management of anaemia of prematurity in a country with limited resources. An open controlled trial was conducted on 93 preterm infants (7 days postnatal age, 900-1500 g birthweight). Patients were randomly assigned either to a low dose (250 IU/kg), a high dose (400 IU/kg), or a control group. EPO was administered subcutaneously three times a week and all infants received 6 mg/kg iron orally from study entry to endpoint of therapy. Haematological parameters were measured and compared. The success was defined as an absence of transfusions and a haematocrit that did not fall below 30 per cent during the time period that the infants were in the study. The three groups were statistically comparable at study entry with respect to gestational age, birthweight, Apgar scores, and haematological values. Over the period that the infants were in the study, 75 per cent of the low dose group and 71 per cent of the high dose group met the criteria for success compared with 40 per cent in the control group (p < 0.001). However, there was no significant difference in the number of transfusions when the low and high EPO dose groups (9.5 per cent) were combined and compared with the control group (26.7 per cent) p = 0.0587. It was concluded that in stable infants, 900-1500 g, where phlebotomy losses are minimized and stringent transfusion guidelines are adhered to, EPO does not significantly decrease the number of transfusions. A conservative approach in the management of anaemia of prematurity, is a viable alternative in areas with limited resources.

Experience with a clinical guideline for the treatment of ventilator-associated pneumonia

OBJECTIVE

To evaluate a clinical guideline for the treatment of ventilator-associated pneumonia.

DESIGN

Prospective before-and-after study design.

SETTING

A medical intensive care unit from a university-affiliated, urban teaching hospital.

PATIENTS

Between April 1999 and January 2000, 102 patients were prospectively evaluated.

INTERVENTIONS

Prospective patient surveillance, data collection, and implementation of an antimicrobial guideline for the treatment of ventilator-associated pneumonia.

MEASUREMENTS AND MAIN RESULTS

The main outcome evaluated was the initial administration of adequate antimicrobial treatment as determined by respiratory tract cultures. Secondary outcomes evaluated included the duration of antimicrobial treatment for ventilator-associated pneumonia, hospital mortality, intensive care unit and hospital lengths of stay, and the occurrence of a second episode of ventilator-associated pneumonia. Fifty consecutive patients with ventilator-associated pneumonia were evaluated in the before period and 52 consecutive patients with ventilator-associated pneumonia were evaluated in the after period. Severity of illness using Acute Physiology and Chronic Health Evaluation II (25.8 +/- 5.7 vs. 25.4 +/- 8.1, p =.798) and the clinical pulmonary infection scores (6.6 +/- 1.0 vs. 6.9 +/- 1.2, p =.105) were similar for patients during the two treatment periods. The initial administration of adequate antimicrobial treatment was statistically greater during the after period compared with the before period (94.2% vs. 48.0%, p <.001). The duration of antimicrobial treatment was statistically shorter during the after period compared with the before period (8.6 +/- 5.1 days vs. 14.8 +/- 8.1 days, p <.001). A second episode of ventilator-associated pneumonia occurred statistically less often among patients in the after period (7.7% vs. 24.0%, p =.030).

CONCLUSIONS

The application of a clinical guideline for the treatment of ventilator-associated pneumonia can increase the initial administration of adequate antimicrobial treatment and decrease the overall duration of antibiotic treatment. These findings suggest that similar types of guidelines employing local microbiological data can be used to improve overall antibiotic utilization for the treatment of ventilator-associated pneumonia.

Defective neutrophil degranulation induced by interleukin-8 and complement 5a and down-regulation of associated receptors in children vertically infected with human immunodeficiency virus type 1

The polymorphonuclear neutrophils (PMNs) of patients infected with human immunodeficiency virus type 1 (HIV-1) show impaired microbicidal responses. The present study assessed the functional integrity of PMN degranulation responses and the expression of specific receptors that mediate these responses in a group of children vertically infected with HIV-1. PMN degranulation in response to interleukin-8 (IL-8) and complement 5a (C5a) was measured in a group of HIV-1-infected children with mild and severe clinical disease and in an uninfected control group. In addition, the expression of CXCR1, CXCR2, and CD88 on whole-blood PMNs was quantified by flow cytometry. Although CXCR1 expression was found to be largely unaltered in the HIV-1-infected children relative to that in the control children, the intensity of CXCR2 expression was significantly reduced in those with severe disease. Furthermore, there was a significant reduction in the percentage of cells expressing CD88 and in the intensity of CD88 fluorescence in the HIV-1-infected children compared to that in control children, with CD88 fluorescence intensity more significantly reduced in the presence of severe disease. PMNs from a large proportion of the HIV-1-infected children either showed reciprocal degranulation responses or were unresponsive to IL-8 and C5a, whereas the PMNs from the uninfected children showed positive responses. Inefficient agonist-induced degranulation may contribute to the increased susceptibility of HIV-1-infected children to secondary microbial infections. Furthermore, reduced expression of CXCR2 and CD88 may be suggestive of defects in other functions of PMNs from HIV-1-infected children.

Inadequate treatment of nosocomial infections is associated with certain empiric antibiotic choices

OBJECTIVE

The purpose of this study was to determine the impact of scheduled changes of antibiotic classes, used for the empirical treatment of suspected or documented Gram-negative bacterial infections, on the occurrence of inadequate antimicrobial treatment of nosocomial infections.

DESIGN

Prospective observational study.

SETTING

Medical (19-bed) and surgical (18-bed) intensive care units in an urban teaching hospital.

PATIENTS

A total of 3,668 patients requiring intensive care unit admission were prospectively evaluated during three consecutive time periods.

INTERVENTIONS

During each time period, one antibiotic class was selected for the empirical treatment of Gram-negative bacterial infections as follows: time period 1 (baseline period) (1,323 patients), ceftazidime; time period 2 (1,243 patients), ciprofloxacin; and time period 3 (1,102 patients), cefepime.

MEASUREMENTS AND MAIN RESULTS

The overall administration of inadequate antimicrobial treatment for nosocomial infections decreased during the course of the study (6.1%, 4.7%, and 4.5%; p = .15). This was primarily because of a statistically significant decrease in the administration of inadequate antibiotic treatment for Gram-negative bacterial infections (4.4%, 2.1%, and 1.6%; p < .001). There were no statistically significant differences in the overall hospital mortality rate among the three time periods (15.6%, 16.4%, and 16.2%; p = .828) despite a significant increase in severity of illness as measured with Acute Physiology and Chronic Health Evaluation (APACHE) II scores (15.3 +/- 7.6, 15.7 +/- 8.0, and 20.7 +/- 8.6; p < .001). The hospital mortality rate decreased significantly during time period 3 (20.6%) compared with time period 1 (28.4%; p < .001) and time period 2 (29.5%; p < .001) for patients with an APACHE II score > or = 15.

CONCLUSIONS

These data suggest that scheduled changes of antibiotic classes for the empirical treatment of Gram-negative bacterial infections can reduce the occurrence of inadequate antibiotic treatment for nosocomial infections. Reducing inadequate antibiotic administration may improve the outcomes of critically ill patients with APACHE II scores > or = 15.

Early versus late tracheostomy in patients who require prolonged mechanical ventilation

OBJECTIVES: To compare the clinical outcomes of early versus late tracheostomy in patients who require prolonged mechanical ventilation. METHODS: A prospective observational study was done. The sample was a cohort of 90 patients who had tracheostomy in the medical intensive care unit of a university-affiliated teaching hospital. Primary outcome measures were duration of mechanical ventilation and total cost of hospitalization. Tracheostomy was defined as early if performed by day 10 of mechanical ventilation and late if performed thereafter. RESULTS: Fifty-three patients had early tracheostomy (mean +/- SD = day 5.9 +/- 7.2 of ventilation), and 37 patients had late tracheostomy (mean +/- SD = day 16.7 +/- 2.9) (P &lt; .001). The mean (+/- SD) duration of mechanical ventilation was 28.3 +/- 28.2 days in the early-tracheostomy group versus 34.4 +/- 17.8 days in the late-tracheostomy group (P = .005). Total cost of hospitalization was significantly lower in the early-tracheostomy group (mean +/- SD = $86,189 +/- $53,570) than in the late-tracheostomy group (mean +/- SD = $124,649 +/- $54,282) (P = .001). Male sex (adjusted odds ratio = 3.84; 95% CI = 2.32-6.34; P = .007) and higher ratios of PaO2 to fraction of inspired oxygen (adjusted odds ratio = 1.01; 95% CI = 1.00-1.01; P = .03) were associated with early tracheostomy. The timing of tracheostomy was not associated with hospital mortality. CONCLUSION: Early tracheostomy is associated with shorter lengths of stay and lower hospital costs than is late tracheostomy among patients in the medical intensive care unit. Prospective clinical trials are necessary to determine the optimal timing of tracheostomy in that setting.

Early versus late tracheostomy in patients who require prolonged mechanical ventilation

OBJECTIVES

To compare the clinical outcomes of early versus late tracheostomy in patients who require prolonged mechanical ventilation.

METHODS

A prospective observational study was done. The sample was a cohort of 90 patients who had tracheostomy in the medical intensive care unit of a university-affiliated teaching hospital. Primary outcome measures were duration of mechanical ventilation and total cost of hospitalization. Tracheostomy was defined as early if performed by day 10 of mechanical ventilation and late if performed thereafter.

RESULTS

Fifty-three patients had early tracheostomy (mean +/- SD = day 5.9 +/- 7.2 of ventilation), and 37 patients had late tracheostomy (mean +/- SD = day 16.7 +/- 2.9) (P < .001). The mean (+/- SD) duration of mechanical ventilation was 28.3 +/- 28.2 days in the early-tracheostomy group versus 34.4 +/- 17.8 days in the late-tracheostomy group (P = .005). Total cost of hospitalization was significantly lower in the early-tracheostomy group (mean +/- SD = $86,189 +/- $53,570) than in the late-tracheostomy group (mean +/- SD = $124,649 +/- $54,282) (P = .001). Male sex (adjusted odds ratio = 3.84; 95% CI = 2.32-6.34; P = .007) and higher ratios of PaO2 to fraction of inspired oxygen (adjusted odds ratio = 1.01; 95% CI = 1.00-1.01; P = .03) were associated with early tracheostomy. The timing of tracheostomy was not associated with hospital mortality.

CONCLUSION

Early tracheostomy is associated with shorter lengths of stay and lower hospital costs than is late tracheostomy among patients in the medical intensive care unit. Prospective clinical trials are necessary to determine the optimal timing of tracheostomy in that setting.

The influence of inadequate antimicrobial treatment of bloodstream infections on patient outcomes in the ICU setting

STUDY OBJECTIVE

To evaluate the relationship between the adequacy of antimicrobial treatment for bloodstream infections and clinical outcomes among patients requiring ICU admission.

DESIGN

Prospective cohort study.

SETTING

A medical ICU (19 beds) and a surgical ICU (18 beds) from a university-affiliated urban teaching hospital.

PATIENTS

Between July 1997 and July 1999, 492 patients were prospectively evaluated.

INTERVENTION

Prospective patient surveillance and data collection.

RESULTS

One hundred forty-seven patients (29.9%) received inadequate antimicrobial treatment for their bloodstream infections. The hospital mortality rate of patients with a bloodstream infection receiving inadequate antimicrobial treatment (61.9%) was statistically greater than the hospital mortality rate of patients with a bloodstream infection who received adequate antimicrobial treatment (28.4%; relative risk, 2. 18; 95% confidence interval [CI], 1.77 to 2.69; p < 0.001). Multiple logistic regression analysis identified the administration of inadequate antimicrobial treatment as an independent determinant of hospital mortality (adjusted odds ratio [AOR], 6.86; 95% CI, 5.09 to 9.24; p < 0.001). The most commonly identified bloodstream pathogens and their associated rates of inadequate antimicrobial treatment included vancomycin-resistant enterococci (n = 17; 100%), Candida species (n = 41; 95.1%), oxacillin-resistant Staphylococcus aureus (n = 46; 32.6%), coagulase-negative staphylococci (n = 96; 21.9%), and Pseudomonas aeruginosa (n = 22; 10.0%). A statistically significant relationship was found between the rates of inadequate antimicrobial treatment for individual microorganisms and their associated rates of hospital mortality (Spearman correlation coefficient = 0.8287; p = 0.006). Multiple logistic regression analysis also demonstrated that a bloodstream infection attributed to Candida species (AOR, 51.86; 95% CI, 24.57 to 109.49; p < 0.001), prior administration of antibiotics during the same hospitalization (AOR, 2.08; 95% CI, 1.58 to 2.74; p = 0.008), decreasing serum albumin concentrations (1-g/dL decrements) (AOR, 1.37; 95% CI, 1.21 to 1.56; p = 0.014), and increasing central catheter duration (1-day increments) (AOR, 1.03; 95% CI, 1.02 to 1.04; p = 0.008) were independently associated with the administration of inadequate antimicrobial treatment.

CONCLUSIONS

The administration of inadequate antimicrobial treatment to critically ill patients with bloodstream infections is associated with a greater hospital mortality compared with adequate antimicrobial treatment of bloodstream infections. These data suggest that clinical efforts should be aimed at reducing the administration of inadequate antimicrobial treatment to hospitalized patients with bloodstream infections, especially individuals infected with antibiotic-resistant bacteria and Candida species.

A comparative analysis of patients with early-onset vs late-onset nosocomial pneumonia in the ICU setting

STUDY OBJECTIVE

To compare the clinical outcomes of critically ill patients developing early-onset nosocomial pneumonia (NP; ie, within 96 h of ICU admission) and late-onset NP (ie, occurring after 96 h of ICU admission).

DESIGN

Prospective cohort study.

SETTING

A medical ICU and a surgical ICU from a university-affiliated urban teaching hospital.

PATIENTS

Between July 1997 and November 1998, 3, 668 patients were prospectively evaluated.

INTERVENTION

Prospective patient surveillance and data collection.

RESULTS

Four hundred twenty patients (11.5%) developed NP. Early-onset NP was observed in 235 patients (56.0%), whereas 185 patients (44.0%) developed late-onset NP. Among patients with early onset NP, 114 patients (48. 5%) spent at least 24 h in the hospital prior to ICU admission, compared to 57 patients (30.8%) with late-onset NP (p = 0.001). One hundred eighty-three patients (77.9%) with early-onset NP received antibiotics prior to the development of NP, as compared to 162 patients (87.6%) with late-onset NP (p = 0.010). The most common pathogens associated with early-onset NP were Pseudomonas aeruginosa (25.1%), oxacillin-sensitive Staphylococcus aureus (OSSA; 17.9%), oxacillin-resistant S aureus (ORSA; 17.9%), and Enterobacter species (10.2%). P aeruginosa (38.4%), ORSA (21.1%), Stenotrophomonas maltophilia (11.4%), OSSA (10.8%), and Enterobacter species (10.3%) were the most common pathogens associated with late-onset NP. The ICU length of stay was significantly longer for patients with early-onset NP (10.3 +/- 8.3 days; p < 0.001) and late-onset NP (21. 0 +/- 13.7 days; p < 0.001), as compared to patients without NP (3.5 +/- 3.2 days). Hospital mortality was significantly greater for patients with early-onset NP (37.9%; p = 0.001) and late-onset NP (41.1%; p = 0.001) compared to patients without NP (13.1%).

CONCLUSIONS

Both early-onset and late-onset NP are associated with increased hospital mortality rates and prolonged lengths of stay. The pathogens associated with NP were similar for both groups. This may be due, in part, to the prior hospitalization and use of antibiotics in many patients developing early-onset NP. These data suggest that P aeruginosa and ORSA can be important pathogens associated with early-onset NP in the ICU setting. Additionally, clinicians should be aware of the common microorganisms associated with both early-onset NP and late-onset NP in their hospitals in order to avoid the administration of inadequate antimicrobial treatment.

Effect of a nursing-implemented sedation protocol on the duration of mechanical ventilation

OBJECTIVE

To compare a practice of protocol-directed sedation during mechanical ventilation implemented by nurses with traditional non-protocol-directed sedation administration.

DESIGN

Randomized, controlled clinical trial.

SETTING

Medical intensive care unit (19 beds) in an urban teaching hospital.

PATIENTS

Patients requiring mechanical ventilation (n = 321).

INTERVENTIONS

Patients were randomly assigned to receive either protocol-directed sedation (n = 162) or non-protocol-directed sedation (n = 159).

MEASUREMENTS AND MAIN RESULTS

The median duration of mechanical ventilation was 55.9 hrs (95% confidence interval, 41.0-90.0 hrs) for patients managed with protocol-directed sedation and 117.0 hrs (95% confidence interval, 96.0-155.6 hrs) for patients receiving non-protocol-directed sedation. Kaplan-Meier analysis demonstrated that patients in the protocol-directed sedation group had statistically shorter durations of mechanical ventilation than patients in the non-protocol-directed sedation group (chi-square = 7.00, p = .008, log rank test; chi-square = 8.54, p = .004, Wilcoxon's test; chi-square = 9.18, p = .003, -2 log test). Lengths of stay in the intensive care unit (5.7+/-5.9 days vs. 7.5+/-6.5 days; p = .013) and hospital (14.0+/-17.3 days vs. 19.9+/-24.2 days; p < .001) were also significantly shorter among patients in the protocol-directed sedation group. Among the 132 patients (41.1%) receiving continuous intravenous sedation, those in the protocol-directed sedation group (n = 66) had a significantly shorter duration of continuous intravenous sedation than those in the non-protocol-directed sedation group (n = 66) (3.5+/-4.0 days vs. 5.6+/-6.4 days; p = .003). Patients in the protocol-directed sedation group also had a significantly lower tracheostomy rate compared with patients in the non-protocol-directed sedation group (10 of 162 patients [6.2%] vs. 21 of 159 patients [13.2%], p = .038).

CONCLUSIONS

The use of protocol-directed sedation can reduce the duration of mechanical ventilation, the intensive care unit and hospital lengths of stay, and the need for tracheostomy among critically ill patients with acute respiratory failure.

Correlation between CD4+ lymphocyte counts, concurrent antigen skin test and tuberculin skin test reactivity in human immunodeficiency virus type 1-infected and -uninfected children with tuberculosis

BACKGROUND

HIV-infected children are at high risk of developing tuberculosis after infection by Mycobacterium tuberculosis. Emphasis is placed on tuberculin skin testing (TST) for diagnosing tuberculosis in children; however, its value in HIV-infected children is controversial.

OBJECTIVES

To determine whether concurrent antigen testing and/or CD4+ lymphocyte counts help in the interpretation of the TST in children with tuberculosis.

METHODS

Children eligible for the study were diagnosed as having tuberculosis on clinical criteria. CD4+ lymphocyte counts and delayed-type hypersensitivity (DTH) test, using the CMI Multitest were performed when tuberculosis was diagnosed.

RESULTS

One hundred thirty children were enrolled. Tuberculin reactivity was lower in HIV-infected children at all cutoff levels than in HIV-uninfected children (P < 0.0001). The positive predictive value of normal CD4+ lymphocyte counts in predicting tuberculin reactions of > or =5 mm (in HIV-1-infected) and > or =10 mm (in HIV-uninfected patients) were 50 and 80.3%, respectively (P < 0.0001). An intact DTH reaction to the CMI Multitest in predicting reactions of > or =5 mm and > or =10 mm to tuberculin in HIV-infected and -uninfected children were 55 and 76%, respectively (P < 0.001). Kwashiorkor was responsible for 53.3% of false-negative TST in HIV-uninfected children with normal CD4+ lymphocyte counts.

CONCLUSION

TST is of limited value as an adjunct in diagnosing tuberculosis in HIV-infected children. CD4+ lymphocyte counts and concurrent DTH testing are not useful for predicting tuberculin reactivity in HIV-infected patients with tuberculosis.

Acquired organ system derangements and hospital mortality: are all organ systems created equally?

BACKGROUND: Acquired organ system derangements are common among patients who require intensive care, but the relative importance of different derangements as determinants of patients' outcomes is unclear. OBJECTIVES: To determine organ system derangements that occur in patients who require intensive care and the relative importance of different derangements to hospital mortality. METHODS: A prospective cohort study design was used to evaluate the occurrence of organ system derangements and hospital mortality in 617 adults admitted to the medical and surgical intensive care units of a university-affiliated teaching hospital. RESULTS: Eighty-three patients (13.5%) died while hospitalized. Patients who died had significantly more derangements than did patients who survived (3.3 +/- 1.2 vs 0.9 +/- 0.9; P &lt; .001). The crude hospital mortality rate varied with the specific organ system involved (pulmonary, 23.6%; gastrointestinal, 25.0%; hepatic, 42.4%; hematological, 47.9%; cardiac, 54.0%; renal, 54.8%; neurological, 65.9%). Derangements of neurological function (adjusted odds ratio, 3.20; 95% CI, 2.0-5.3; P = .019) and cardiac function (adjusted odds ratio, 3.96; 95% CI, 2.63-5.99; P &lt; .001) were independently associated with hospital mortality. Additionally, derangements occurred later during the stay in the intensive care unit in patients who died in the hospital than in patients who survived, especially for derangements of pulmonary, neurological, and renal function. CONCLUSION: Among critically ill patients, neurological and cardiac dysfunction are the acquired organ system derangements most closely associated with hospital mortality. These data suggest that hospital mortality depends on both the specific types of derangements that occur and the total number of such derangements. Interventions to prevent cardiac and neurological dysfunction have the greatest potential for improving outcomes for patients in the intensive care unit.

Acquired organ system derangements and hospital mortality: are all organ systems created equally?

BACKGROUND

Acquired organ system derangements are common among patients who require intensive care, but the relative importance of different derangements as determinants of patients' outcomes is unclear.

OBJECTIVES

To determine organ system derangements that occur in patients who require intensive care and the relative importance of different derangements to hospital mortality.

METHODS

A prospective cohort study design was used to evaluate the occurrence of organ system derangements and hospital mortality in 617 adults admitted to the medical and surgical intensive care units of a university-affiliated teaching hospital.

RESULTS

Eighty-three patients (13.5%) died while hospitalized. Patients who died had significantly more derangements than did patients who survived (3.3 +/- 1.2 vs 0.9 +/- 0.9; P < .001). The crude hospital mortality rate varied with the specific organ system involved (pulmonary, 23.6%; gastrointestinal, 25.0%; hepatic, 42.4%; hematological, 47.9%; cardiac, 54.0%; renal, 54.8%; neurological, 65.9%). Derangements of neurological function (adjusted odds ratio, 3.20; 95% CI, 2.0-5.3; P = .019) and cardiac function (adjusted odds ratio, 3.96; 95% CI, 2.63-5.99; P < .001) were independently associated with hospital mortality. Additionally, derangements occurred later during the stay in the intensive care unit in patients who died in the hospital than in patients who survived, especially for derangements of pulmonary, neurological, and renal function.

CONCLUSION

Among critically ill patients, neurological and cardiac dysfunction are the acquired organ system derangements most closely associated with hospital mortality. These data suggest that hospital mortality depends on both the specific types of derangements that occur and the total number of such derangements. Interventions to prevent cardiac and neurological dysfunction have the greatest potential for improving outcomes for patients in the intensive care unit.

Inadequate antimicrobial treatment of infections: a risk factor for hospital mortality among critically ill patients

STUDY OBJECTIVE

To evaluate the relationship between inadequate antimicrobial treatment of infections (both community-acquired and nosocomial infections) and hospital mortality for patients requiring ICU admission.

DESIGN

Prospective cohort study.

SETTING

Barnes-Jewish Hospital, a university-affiliated urban teaching hospital.

PATIENTS

Two thousand consecutive patients requiring admission to the medical or surgical ICU.

INTERVENTIONS

Prospective patient surveillance and data collection.

MEASUREMENTS AND RESULTS

One hundred sixty-nine (8.5%) infected patients received inadequate antimicrobial treatment of their infections. This represented 25.8% of the 655 patients assessed to have either community-acquired or nosocomial infections. The occurrence of inadequate antimicrobial treatment of infection was most common among patients with nosocomial infections, which developed after treatment of a community-acquired infection (45.2%), followed by patients with nosocomial infections alone (34.3%) and patients with community-acquired infections alone (17.1%) (p < 0.001). Multiple logistic regression analysis, using only the cohort of infected patients (n = 655), demonstrated that the prior administration of antibiotics (adjusted odds ratio [OR], 3.39; 95% confidence interval [CI], 2.88 to 4.23; p < 0.001), presence of a bloodstream infection (adjusted OR, 1.88; 95% CI, 1.52 to 2.32; p = 0.003), increasing acute physiology and chronic health evaluation (APACHE) II scores (adjusted OR, 1.04; 95% CI, 1.03 to 1.05; p = 0.002), and decreasing patient age (adjusted OR, 1.01; 95% CI, 1.01 to 1.02; p = 0.012) were independently associated with the administration of inadequate antimicrobial treatment. The hospital mortality rate of infected patients receiving inadequate antimicrobial treatment (52.1%) was statistically greater than the hospital mortality rate of the remaining patients in the cohort (n = 1,831) without this risk factor (12.2%) (relative risk [RR], 4.26; 95% CI, 3.52 to 5.15; p < 0.001). Similarly, the infection-related mortality rate for infected patients receiving inadequate antimicrobial treatment (42.0%) was significantly greater than the infection-related mortality rate of infected patients receiving adequate antimicrobial treatment (17.7%) (RR, 2.37; 95% CI, 1.83 to 3.08; p < 0.001). Using a logistic regression model, inadequate antimicrobial treatment of infection was found to be the most important independent determinant of hospital mortality for the entire patient cohort (adjusted OR, 4.27; 95% CI, 3.35 to 5.44; p < 0.001). The other identified independent determinants of hospital mortality included the number of acquired organ system derangements, use of vasopressor agents, the presence of an underlying malignancy, increasing APACHE II scores, increasing age, and having a nonsurgical diagnosis at the time of ICU admission.

CONCLUSIONS

Inadequate treatment of infections among patients requiring ICU admission appears to be an important determinant of hospital mortality. These data suggest that clinical efforts aimed at reducing the occurrence of inadequate antimicrobial treatment could improve the outcomes of critically ill patients. Additionally, prior antimicrobial therapy should be recognized as an important risk factor for the administration of inadequate antimicrobial treatment among ICU patients with clinically suspected infections.

The use of continuous i.v. sedation is associated with prolongation of mechanical ventilation

STUDY OBJECTIVE

To determine whether the use of continuous i.v. sedation is associated with prolongation of the duration of mechanical ventilation.

DESIGN

Prospective observational cohort study.

SETTING

The medical ICU of Barnes-Jewish Hospital, a university-affiliated urban teaching hospital.

PATIENTS

Two hundred forty-two consecutive ICU patients requiring mechanical ventilation.

INTERVENTIONS

Patient surveillance and data collection.

MEASUREMENTS AND RESULTS

The primary outcome measure was the duration of mechanical ventilation. Secondary outcome measures included ICU and hospital lengths of stay, hospital mortality, and acquired organ system derangements. A total of 93 (38.4%) mechanically ventilated patients received continuous i.v. sedation while 149 (61.6%) patients received either bolus administration of i.v. sedation (n=64) or no i.v. sedation (n=85) following intubation. The duration of mechanical ventilation was significantly longer for patients receiving continuous i.v. sedation compared with patients not receiving continuous i.v. sedation (185+/-190 h vs 55.6+/-75.6 h; p<0.001). Similarly, the lengths of intensive care (13.5+/-33.7 days vs 4.8+/-4.1 days; p<0.001) and hospitalization (21.0+/-25.1 days vs 12.8+/-14.1 days; p<0.001) were statistically longer among patients receiving continuous i.v. sedation. Multiple linear regression analysis, adjusting for age, gender, severity of illness, mortality, indication for mechanical ventilation, use of chemical paralysis, presence of a tracheostomy, and the number of acquired organ system derangements, found the adjusted duration of mechanical ventilation to be significantly longer for patients receiving continuous i.v. sedation compared with patients who did not receive continuous i.v. sedation (148 h [95% confidence interval: 121, 175 h] vs 78.7 h [95% confidence interval: 68.9, 88.6 h]; p<0.001).

CONCLUSION

We conclude from these preliminary observational data that the use of continuous i.v. sedation may be associated with the prolongation of mechanical ventilation. This study suggests that strategies targeted at reducing the use of continuous i.v. sedation could shorten the duration of mechanical ventilation for some patients. Prospective randomized clinical trials, using well-designed sedation guidelines and protocols, are required to determine whether patient-specific outcomes (eg, duration of mechanical ventilation, patient comfort) can be improved compared with conventional sedation practices.

Nonprescription chlorpheniramine maleate and submaximal exercise responses

OBJECTIVE

To determine if a single, over-the-counter dose of the H1 antagonist chlorpheniramine maleate (CM) alters total peripheral resistance (TPR) and oxygen uptake (VO2) during submaximal exercise.

DESIGN

The study was a prospective, longitudinal, double-blind, random crossover analysis of the cardiovascular and respiratory responses to a single bout of moderately intense exercise.

SETTING

Exercise tests were conducted in an exercise laboratory equipped with expired gas analysis and bioelectrical impedance cardiographic monitoring capabilities.

PARTICIPANTS

Subjects were 18 (9 men, 9 women) volunteers (age=29.5+/-3.6yrs; weight=70.7+/-1.1kg), free from exercise-limiting pathology and rhinitis.

INTERVENTION

Each subject completed a maximal exercise tolerance test on the cycle ergometer followed by two randomly ordered submaximal exercise tests at a power output of 50% of the peak power attained on the maximal test: the first, 2 hours after ingesting 4mg of CM, the second, 2 hours after ingesting a placebo. The submaximal exercise tests lasted 20min and data were recorded at 5, 10, 15, and 20min of exercise during both the CM and placebo tests. Tests were completed approximately 48 hours apart.

RESULTS

Average VO2 was 1,488+/-367mL/min for the CM test and 1,477+/-351mL/min for the placebo test. TPR was 12.3+/-7.4PRU for the CM and 11.3+/-4.5PRU for the placebo tests. Analysis of variance revealed that these scores were statistically similar.

CONCLUSION

A single over-the-counter dose of CM does not alter TPR or VO2 during submaximal exercise.

Effects of embryo transfer and cortical ectopias upon the behavior of BXSB-Yaa and BXSB-Yaa + mice

The BXSB-Yaa and BXSB-Yaa + inbred strains of mice differ primarily with respect to the Y chromosome, although there is evidence that they differ on several autosomal genes as well. Each strain has ectopic collections of neurons in neocortical layer I (ectopias), with a higher occurrence in males (58%) than females (42%). Conventionally reared mice from these strains were compared to mice that were transferred, as 8-cell embryos, into the uteri of non-autoimmune recipients, who gave birth to and reared the offspring. The transfer procedure did not change the incidence of ectopias in either sex. There were, however, major differences in behavior. Compared to conventionally reared controls, embryo transfer mice had greater behavioral asymmetry, poorer performance in a black-white discrimination, poorer Morris maze learning, better Lashley maze learning, and better performance in a two-way shuttlebox. Within the transfer groups, females differed as much as males, confirming our prior findings and supporting our thesis that the two strains differ on several autosomal genes in addition to the Y chromosome. These findings show that the intra-uterine environment can powerfully and selectively affect later behavior. When ectopic and non-ectopic mice were compared, BXSB-Yaa mice with neocortical ectopias were better able to learn the Morris spatial maze than non-ectopic controls; this was true whether the mice were conventionally reared or embryo transferred. In contrast, BXSB-Yaa + ectopic mice did not differ from their controls if conventionally reared, but were much worse than controls if embryo transferred.

The covalently closed duplex form of the hepadnavirus genome exists in situ as a heterogeneous population of viral minichromosomes

Replication of hepadnaviruses requires a persistent population of covalently closed circular (CCC) DNA molecules in the nucleus of the infected cell. It is widely accepted that the vital role of this molecule is to be the sole DNA template for the synthesis by RNA polymerase II of all viral transcripts throughout the infection process. Since the transcriptional activity of eukaryotic nuclear DNA is considered to be determined in part by its specific organization as chromatin, the nucleoprotein disposition of the hepadnavirus CCC DNA was investigated. These studies were undertaken on the duck hepatitis B virus (DHBV) CCC DNA present in the liver cell nuclei of DHBV-infected ducks. The organization and protein associations of the DHBV CCC DNA in situ were inferred from sedimentation, micrococcal nuclease digestion, and DNA superhelicity analyses. These three lines of investigation demonstrate that the DHBV CCC DNA is stably associated with proteins in the nuclei of infected liver cells. Moreover, they provide compelling evidence that the viral nucleoprotein complex is indeed a minichromosome composed of classical nucleosomes but in arrays that are atypical for chromatin. When the DHBV chromatin is digested with micrococcal nuclease, a ladder of viral DNA fragments that exhibits a 150-bp repeat is produced. This profile for the viral chromatin is obtained from the same nuclei in which the duck chromatin shows the standard 200-bp ladder. The superhelicity of the DHBV CCC DNA ranges from 0 to 20 negative supertwists per molecule, with all possible 21 topoisomers present in each DNA preparation. The 21 topoisomers of DHBV CCC DNA are inferred to derive from an identically diverse array of viral minichromosomes. In the DHBV minichromosomes composed of 20 nucleosomes, 96.7% of the viral DNA is calculated to be compacted into these chromatin subunits spaced on average by 5 bp of linker DNA; other minichromosomes contain fewer nucleosomes and proportionately more linker DNA. Two major subpopulations of DHBV minichromosomes are detected with comparable prevalence. The two groups correspond to minichromosomes which contain essentially a full or half complement of nucleosomes. The functional significance of this minichromosome diversity is unknown but is suggestive of transcriptional regulation of the viral DNA template.

Case-control study of congenital anomalies in children of cancer patients

OBJECTIVES

To determine whether the offspring of cancer survivors are at an increased risk of congenital anomalies and whether cancer therapy before conception is associated with such an increase.

DESIGN

Case-control study using computerised record linkage.

SETTING

Ontario, Canada.

SUBJECTS

Parents of children born during April 1979 to December 1986 who had a congenital anomaly diagnosed within the first year of life (45,200 mothers and 41,158 fathers) and a matched sample of parents whose children did not have a congenital anomaly (45,200 mothers and 41,158 fathers).

MAIN OUTCOME MEASURES

Cancer diagnosed in either parent before conception and radiotherapy to the pelvis or abdomen or chemotherapy with an alkylating agent.

RESULTS

Among the mothers, 54 cases and 52 controls were identified as having had cancer diagnosed in Ontario (relative risk = 1.04, 95% confidence interval 0.7 to 1.5) and among the fathers, 61 cases and 65 controls were identified (0.9, 0.7 to 1.4). No significant associations were found between congenital anomalies in the offspring and any type of cancer treatment in either the mothers or the fathers.

CONCLUSIONS

The risk of congenital anomalies among liveborn offspring whose parents have had cancer or been treated for cancer is not higher than that in the general population.

The UL8 subunit of the herpes simplex virus helicase-primase complex is required for efficient primer utilization

The herpes simplex virus (HSV) type 1 helicase-primase is a three-protein complex, consisting of a 1:1:1 association of UL5, UL8, and UL52 gene products (J.J. Crute, T. Tsurumi, L. Zhu, S. K. Weller, P. D. Olivo, M. D. Challberg, E. S. Mocarski, and I. R. Lehman, Proc. Natl. Acad. Sci. USA 86:2186-2189, 1989). We have purified this complex, as well as a subcomplex consisting of UL5 and UL52 proteins, from insect cells infected with baculovirus recombinants expressing the appropriate gene products. In confirmation of previous reports, we find that whereas UL5 alone has greatly reduced DNA-dependent ATPase activity, the UL5/UL52 subcomplex retains the activities characteristic of the heterotrimer: DNA-dependent ATPase activity, DNA helicase activity, and the ability to prime DNA synthesis on a poly(dT) template. We also found that the primers made by the subcomplex are equal in length to those synthesized by the UL5/UL8/UL52 complex. In an effort to uncover a role for UL8 in HSV DNA replication, we have developed a model system for lagging-strand synthesis in which the primase activity of the helicase-primase complex is coupled to the activity of the HSV DNA polymerase on ICP8-coated single-stranded M13 DNA. Using this assay, we found that the UL8 subunit of the helicase-primase is critical for the efficient utilization of primers; in the absence of UL8, we detected essentially no elongation of primers despite the fact that the rate of primer synthesis on the same template is undiminished. Reconstitution of lagging-strand synthesis in the presence of UL5/UL52 was achieved by the addition of partially purified UL8. Essentially identical results were obtained when Escherichia coli DNA polymerase I was substituted for the HSV polymerase/UL42 complex. On the basis of these findings, we propose that UL8 acts to increase the efficiency of primer utilization by stabilizing the association between nascent oligoribonucleotide primers and template DNA.

Effect of subarachnoid morphine on the incidence of spinal headache

BACKGROUND AND OBJECTIVES

The addition of fentanyl to hyperbaric local anesthetics has been shown to reduce the incidence of post dural puncture headache in the obstetric patient. This study was undertaken to evaluate the effects of subarachnoid morphine on the incidence of headache.

METHODS

Eighty-two healthy patients undergoing cesarean delivery with spinal anesthesia were studied. All patients were hydrated with 1500 ml lactated Ringer's solution. Patients were randomly assigned to receive, in a double-blind fashion, 0.2 mg of either morphine (Group 1, n = 40) or saline (Group 2, n = 42) in 0.2 ml volume mixed with 0.75% bupivacaine in 8.25% dextrose plus 0.2 ml 1:1000 epinephrine. Spinal anesthesia was induced using a 25-gauge spinal needle at L3-4 interspace with the bevel, in most cases, parallel to the dural fibers. Patients were followed for three days to evaluate the incidence and severity of headache using a four-category rank scale (none, mild, moderate, severe). Data were analyzed for statistical significance using Student's t-test or chi-square test as appropriate. A p value less than 0.05 was considered significant. Results. The incidence of post dural puncture headache did not differ significantly between groups. Eight patients in Group 1 versus nine patients in Group 2 developed headache (p greater than 0.05). Similarly, the use of blood patch or intravenous caffeine sodium benzoate to treat the headache did not differ significantly between groups.

CONCLUSION

It is concluded from our study that subarachnoid morphine did not decrease the incidence of post dural puncture headache in the obstetric patient.

Epidural butorphanol augments lidocaine sensory anesthesia during labor

To determine the efficacy and safety of epidural butorphanol combined with lidocaine, 50 healthy parturients were studied during labor and delivery. All patients received a test dose of 3 ml 1.5% lidocaine with 1:200,000 epinephrine. Patients were then randomly assigned to receive 7 ml of one of two epidural regimens in a double-blind fashion: Group 1 patients received 1.5% lidocaine plus 1 mg butorphanol plus 1:300,000 epinephrine; Group 2 patients received 1.5% lidocaine plus 1:300,000 epinephrine. Each group consisted of 25 patients. The study ended at the time of redosing. All subsequent epidural injections were made with one bolus of plain 0.25% bupivacaine followed by continuous infusion of 0.125% bupivacaine. Duration of anesthesia was significantly longer for Group 1 compared to Group 2 (p less than 0.01), 124 +/- 8 minutes versus 99 +/- 6 minutes (mean +/- SEM). There were no difference between groups in duration of first and second stages of labor, method of delivery or neonatal outcome. Umbilical cord acid-base status and neurologic adaptive capacity scores did not differ significantly between the two groups. The authors conclude that adding small doses of butorphanol to epidural lidocaine during labor is effective and safe.

Body awareness and medical care utilization among older adults in an HMO

This study investigated the association between the disposition of body awareness and medical care utilization among older adult members of a health maintenance organization (HMO). Results indicated that higher levels of body awareness are associated significantly with longitudinal increases in the volume of patient-initiated illness visits to the HMO, and with a greater likelihood of patient-initiated contact with the hospital emergency room, controlling for prior utilization, self-reported health status, and other factors. In contrast, body awareness was not associated significantly with longitudinal changes in physician-initiated follow-up visits, internal referrals, external referrals, or hospital inpatient days. Other findings indicated that higher levels of patient-initiated utilization were associated with greater physician-initiated utilization, controlling for prior utilization. These results illustrate how patient-initiated utilization may influence subsequent physician-initiated utilization.

High-power fast-axial-flow CO2 laser with a variable-reflectivity output coupler

We report what is to our knowledge the first cw, dc-excited, fast-axial-flow CO(2) laser using a variable-reflectivity output coupler. A super-Gaussian reflectivity profile of order 8 with 96% central reflectivity has been achieved by depositing a low-absorption coating onto a ZnSe substrate. The unstable resonator oscillated in the lowest-order mode to produce a diffraction-limited beam of 300 W of power and 0.35-mrad divergence angle (FWHM). The measured near field and far field are in good agreement with the mathematical model. The technique lends itself to extrapolation to the kilowatt level.

Characterization of intranuclear capsids made by ts morphogenic mutants of HSV-1

We have characterized capsids made by seven temperature-sensitive (ts) mutants of HSV-1 previously shown to be defective in viral DNA processing and packaging at the nonpermissive temperature (NPT). The empty capsids isolated from mutant-infected cells at the NPT were devoid of DNA, cosedimented in sucrose with wt B capsids, and contained the same structural proteins found in wt B capsids (W. Gibson and B. Roizman (1972). J. Virol. 10, 1044-1052). The presence of VP22a in empty capsids suggests that the processing of this protein from higher-molecular-weight precursors and its association with capsids is required, but not sufficient, for DNA encapsidation. Mutants made no detectable A capsids at the NPT, but did so at the permissive temperature (PT), suggesting that A particles are generated during or subsequent to, rather than prior to, encapsidation. In temperature-shift experiments, it was demonstrated that capsids of one of the mutants, F18, made at the NPT did not participate in DNA encapsidation when cells were subsequently shifted to the PT. Only those capsids made after temperature shift to the PT acquired viral DNA, implying that the ts mutation in F18 may lie in a gene coding for a structural protein, or in a protein involved in the processing of viral DNA.

Chemicals, birth defects and stillbirths in New Brunswick: associations with agricultural activity

We describe a series of investigations that were conducted in support of the Task Force on Chemicals in the Environment and Human Reproductive Problems in New Brunswick. Geographic and temporal analyses and case-control studies, with the use of vital statistics, hospital records, the Canadian Congenital Anomalies Surveillance System and chemical databases, revealed no association between pesticides used in forestry and reproductive problems. Evidence of an association between the potential exposure to agricultural chemicals and three major anomalies combined as well as spina bifida without hydrocephalus was found. More plausible was an association between stillbirths and such exposure during the second trimester of pregnancy. This finding, along with the cyclic patterns of stillbirth in the agricultural Saint John River basin and the somewhat higher stillbirth rates in New Brunswick than in adjacent provinces or in Canada as a whole, suggests that further attention should focus on possible associations between agricultural activity and stillbirths.

DNA processing in temperature-sensitive morphogenic mutants of HSV-1

The anatomy of DNA synthesized by five HSV-1 mutants previously shown to accumulate predominantly empty capsids at the nonpermissive temperature (NPT) was analyzed with Bg/II restriction digestion. At the NPT, all five generated DNA lacking termini, indicating that in the absence of packaging, viral DNA is not processed to unit length. One mutant, F18, was able to process DNA made at the NPT to unit length molecules during a 6-hr period after shift to the permissive temperature. The appearance of unit length molecules correlated with the appearance of staphylococcal nuclease-resistant F18 DNA.

Recovery of Salmonella Species from Nonfat Dry Milk Rehydrated Under Rapid and Reduced Pre-enrichment Conditions: Collaborative Study

A collaborative study was conducted to compare the relative efficiency of the AOAC rapid rehydration method with the reduced rehydration soak method for the recovery of Salmonella species from nonfat dry milk (NFDM). In the AOAC method, a 25 g sample of NFDM is rapidly rehydrated at a 1:9 sample/water ratio and mixed by swirling. After 60 min, the flask contents are adjusted to a pH of 6.8, and 0.45 mL of 1% aqueous brilliant green dye solution is added. The flasks are then incubated at 35°C. In the soak method, a 25 g sample of NFDM is gently added to the sterile brilliant green (BG) water at a 1:9 sample/ BG water ratio and allowed to soak undisturbed for 60 min at room temperature before incubation. Twelve collaborators analyzed 3 shipments of samples with the following results for the AOAC and soak methods: shipment 1—31 and 46 positive samples, respectively, with a 48% increase in detection by the soak method; shipment 3-45 and 66 positive samples, respectively, with a 47% increase in detection by the soak method; shipment 2—no significant difference in recovery of Salmonella species by the 2 methods. It is recommended that the official final action method for the detection of Salmonella species, 46.054- 46.067, be revised to use the soak method for the analysis of nonfat dry milk.

Selectivity of cholestyramine treatment on hepatic mixed function oxidase activity

The possibility that oral cholestyramine treatment might indirectly increase hepatic drug oxidations was investigated in rats using pentobarbital, antipyrine, zoxazolamine, and aminopyrine as probes of the hepatic mixed function oxidase system and in humans using amobarbital and antipyrine as probes. Cholestyramine pretreatment of rats for 5 days (87.5 mg/kg twice daily by stomach tube) shortened pentobarbital sleep times, decreased antipyrine-induced hypothermia, but did not influence either zoxazolamine paralysis times or the in vitro N-demethylation of aminopyrine. Neither pentobarbital nor antipyrine pharmacokinetics in rats were affected by the cholestyramine pretreatment. Similarly, in two-way crossover studies with human subjects, a 5-day oral cholestyramine pretreatment (4 g 3 times daily) had no demonstrable effect on the pharmacokinetics of single doses of amobarbital (200 mg i.v.) or antipyrine (500 mg per os). After cholestyramine pretreatment, a trend toward diminished CNS depression produced by amobarbital was observed, but the effect was not statistically significant. The results suggest that hepatic mixed function oxidases in rats for which aminopyrine, antipyrine, pentobarbital, and zoxazolamine are substrates and that hepatic mixed function oxidases in humans for which amobarbital and antipyrine are substrates are not significantly affected by cholestyramine pretreatment.

Discriminative response control by naloxone in morphine pretreated rats

In an operant procedure using a lever press response 12 male, hooded rats were trained to discriminate 1.25 mg/kg naloxone from a saline injection. On certain days, according to a counterbalanced training schedule, naloxone was administered 8 h after 40 mg/kg morphine and 10 min prior to a trail in which food was available on an FR10 schedule from one of two levers in a dual lever operant chamber. On other days saline was administered 10 min prior to a trial in which food was made available by pressing the other lever. After criterion performance for acquisition of the discrimination had been reached, tests were carried out to determine its nature. Discrimination of naloxone was dose-dependent and was significantly diminished when naloxone was administered 36 h after morphine. Partial generalization of cyclazocine with naloxone was observed. Spontaneous withdrawal from morphine, tested during trials preceeded by an injection of saline instead of naloxone at various time intervals after morphine, did not generalize with the naloxone discriminative stimulus.

Thick filament size changes in contraction of human muscles

Measurements done on electron micrographs shows that in myofibres with sarcomeres contracted to below 2.1 micron, proportional shortening of the A bands occurs. In muscles from patients with idiopathic scoliosis very short A bands are especially prominent.

Cutaneous basosquamous carcinoma of the head and neck: a comparative analysis

Considerable debate has taken place concerning cutaneous basosquamous carcinomas. Some authors believe they are merely a variant of basal cell carcinoma, based on the apparent rare occurrence of metastases. This comparative study of 33 cases of basosquamous, 1,796 cases of basal cell, and 736 cases of squamous carcinomas arising in the head and neck demonstrates that the basosquamous lesion has the potential to recur and to metastasize, which is similar to squamous cell lesions. An aggressive primary treatment program is recommended.

Primary malignant lymphoma of the small intestine in Israel. Changing incidence with time

One hundred and eighty-one cases of primary small intestinal lymphoma were diagnosed in residents of Israel--145 Jews and 36 Arabs--during a 16-year period, 1960--75. The male:female ratio was 1.8:1. Incidence rates were higher in children, the middle-aged and the elderly than in teenagers or young adults. Crude and age-adjusted incidence rates were higher in Arabs than in Jews. The pattern among the subgroups of the Jewish population varied with age. In young adults of both sexes the rates were much higher among Jews born in North Africa or Asia than among those born in Europe or Israel. In elderly males, however, the rates were almost twice as high in European-born Jews than among those born in North Africa or Asia. The mean annual incidence of primary small intestinal lymphoma fell from 4.8 per million during 1960--67 to 3.6 per million during 1968--75. This was due to a marked fall in the rates in children and young adults, whereas the rates in those aged 40 years or more rose with time. The pattern of the change with time suggests that environmental conditions are an important factor in the causation of primary intestinal lymphoma in young adults.