Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

BACKGROUND

Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks.

METHODS

The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned.

RESULTS

A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31).

CONCLUSION

Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov).

Abdominal wall reconstruction using biosynthetic absorbable mesh in high-risk complex ventral hernia

BACKGROUND

Biosynthetic mesh may represent an improvement on biological and large pore synthetic meshes for high-risk complex ventral hernia repair. This study aimed to evaluate the performance of polyglycolic acid (PGA):trimethylene carbonate (TMC) biosynthetic mesh for reinforcement of the midline fascial closure in a single-stage repair of complex ventral hernias in high-risk patients.

METHODS

A retrospective review was undertaken for patients who underwent a planned open single-stage complex ventral hernia repair with a single unit of PGA:TMC biosynthetic mesh between May 2013 and August 2017. Data on outcome variables were recorded and quality of life assessed using the Short Form-12 (SF-12) instrument.

RESULTS

Overall, 56 patients underwent abdominal wall reconstruction for complex ventral hernias. All meshes were placed in the retrorectus position. Some 39% underwent component separation. The majority of patients (86%, n = 48) had high risk (grade 2 or 3) hernias according to the Ventral Hernia Working Group classification. Overall hernia recurrence rate was 3.6% (n = 2). Postoperative surgical site infection occurred in 26.8% (n = 15). Median follow-up by clinical examination was 6 months (range 4&ndash;17). Median telephone follow-up was 21 months (range 4&ndash;54). Pre- and post-treatment SF-12 quality of life assessments demonstrated significant improvements in both the physical and mental components.

CONCLUSION

This study reports a large series of abdominal wall reconstructions using biosynthetic mesh in complex ventral hernia. The findings indicate promising early outcome data associated with use of biosynthetic mesh. Larger well-controlled studies with longer follow-up are needed for confirmation of these findings.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

A phase II study of the HDAC inhibitor SB939 in patients with castration resistant prostate cancer: NCIC clinical trials group study IND195

BACKGROUND

SB939 is a potent oral inhibitor of class 1, 2, and 4 histone deacetylases (HDACs). These three HDAC classes are highly expressed in castration resistant prostate cancer (CRPC) and associated with poor clinical outcomes. We designed a phase II study of SB939 in men with metastatic CRPC.

METHODS

Patients received SB939 60 mg on alternate days three times per week for 3 weeks on a 4-week cycle. Primary endpoints were PSA response rate (RR) and progression-free survival (PFS). Secondary endpoints included objective response rate and duration; overall survival; circulating tumor cell (CTC) enumeration and safety. Exploratory correlative studies of the TMPRSS2-ERG fusion and PTEN biomarkers were also performed.

RESULTS

Thirty-two patients were enrolled of whom 88 % had received no prior chemotherapy. The median number of SB939 cycles administered was three (range 1-8). Adverse events were generally grade 1-2, with five pts experiencing one or more grade three event. One patient died due to myocardial infarction. A confirmed PSA response was noted in two pts (6 %), lasting 3.0 and 21.6 months. In patients with measurable disease there were no objective responses. Six patients had stable disease lasting 1.7 to 8.0 months. CTC response (from ≥5 at baseline to <5 at 6 or 12 weeks) occurred in 9/14 evaluable patients (64 %).

CONCLUSION

Although SB939 was tolerable at the dose/schedule given, and showed declines in CTC in the majority of evaluable patients, it did not show sufficient activity based on PSA RR to warrant further study as a single agent in unselected patients with CRPC.

Safety of supervised trainee-performed laparoscopic surgery for inflammatory bowel disease

PURPOSE

There is a significant risk of surgical resection during the lifetime of an inflammatory bowel disease (IBD) patient: laparoscopic surgery has been increasingly applied to the management of IBD with short and long-term advantages. The aim of this study is to demonstrate that laparoscopic surgery for IBD, performed by a surgical trainee under the supervision of an experienced trainer, is feasible and safe.

METHODS

All surgical procedures were sub-divided in six critical steps in order to define the procedure as supervised trainee performed (STP) when the trainer was present unscrubbed in the theatre or assisting and trainer performed (TNER) when the trainer performed two or more critical steps of the procedure. Included were all patients undergoing laparoscopic resection for IBD between January 2009 and December 2013. Thirty-day mortality and morbidity were the primary outcomes. Reoperations and rehospitalizations within 30 days of discharge were recorded prospectively and were the secondary outcomes together with conversion rate and length of hospital stay.

RESULTS

One hundred fifty-one patients were included: 77 (50.99%) STP and 74 (49.01%) TNER. No deaths occurred, and 30-day morbidity was 27.15% with no differences between the groups. Operating time was longer in the STP (166.6 ± 53.31 vs 130.4 ± 49.15). Five patients (2 vs 3) required reoperation (3.31%), while 13 patients (8.6%) required readmission.

CONCLUSIONS

Laparoscopic surgery for IBD performed by a supervised trainee is safe compared to trainers performed procedures despite a longer operating time. Randomized clinical trials are needed to confirm these preliminary results and to investigate long-term outcomes.

CK2 phosphorylation of XRCC1 facilitates dissociation from DNA and single-strand break formation during base excision repair

CK2 phosphorylates the scaffold protein XRCC1, which is required for efficient DNA single-strand break (SSB) repair. Here, we express an XRCC1 protein (XRCC1(ckm)) that cannot be phosphorylated by CK2 in XRCC1 mutated EM9 cells and show that the role of this post-translational modification gives distinct phenotypes in SSB repair and base excision repair (BER). Interestingly, we find that fewer SSBs are formed during BER after treatment with the alkylating agent dimethyl sulfate (DMS) in EM9 cells expressing XRCC1(ckm) (CKM cells) or following inhibition with the CK2 inhibitor 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT). We also show that XRCC1(ckm) protein has a higher affinity for DNA than wild type XRCC1 protein and resides in an immobile fraction on DNA, in particular after damage. We propose a model whereby the increased affinity for DNA sequesters XRCC1(ckm) and the repair enzymes associated with it, at the repair site, which retards kinetics of BER. In conclusion, our results indicate that phosphorylation of XRCC1 by CK2 facilitates the BER incision step, likely by promoting dissociation from DNA.

XRCC1 phosphorylation by CK2 is required for its stability and efficient DNA repair

XRCC1 is a scaffold protein that interacts with several DNA repair proteins and plays a critical role in DNA base excision repair (BER). XRCC1 protein is in a tight complex with DNA ligase IIIalpha (Lig III) and this complex is involved in the ligation step of both BER and repair of DNA single strand breaks. The majority of XRCC1 has previously been demonstrated to exist in a phosphorylated form and cells containing mutant XRCC1, that is unable to be phosphorylated, display a reduced rate of single strand break repair. Here, in an unbiased assay, we demonstrate that the cytoplasmic form of the casein kinase 2 (CK2) protein is the major protein kinase activity involved in phosphorylation of XRCC1 in human cell extracts and that XRCC1 phosphorylation is required for XRCC1-Lig III complex stability. We demonstrate that XRCC1-Lig III complex containing mutant XRCC1, in which CK2 phosphorylation sites have been mutated, is unstable. We also find that a knockdown of CK2 by siRNA results in both reduced XRCC1 phosphorylation and stability, which also leads to a reduced amount of Lig III and accumulation of DNA strand breaks. We therefore propose that CK2 plays an important role in DNA repair by contributing to the stability of XRCC1-Lig III complex.

Cells deficient in the base excision repair protein, DNA polymerase beta, are hypersensitive to oxaliplatin chemotherapy

A significant proportion of human cancers overexpress DNA polymerase beta (Pol beta), the major DNA polymerase involved in base excision repair. The underlying mechanism and biological consequences of overexpression of this protein are unknown. We examined whether Pol beta, expressed at levels found in tumor cells, is involved in the repair of DNA damage induced by oxaliplatin treatment and whether the expression status of this protein alters the sensitivity of cells to oxaliplatin. DNA damage induced by oxaliplatin treatment of HCT116 and HT29 colon cancer cells was observed to be associated with the stabilization of Pol beta protein on chromatin. In comparison with HCT116 colon cancer cells, isogenic oxaliplatin-resistant (HCT-OR) cells were found to have higher constitutive levels of Pol beta protein, faster in vitro repair of a DNA substrate containing a single nucleotide gap and faster repair of 1,2-GG oxaliplatin adduct levels in cells. In HCT-OR cells, small interfering RNA knockdown of Pol beta delayed the repair of oxaliplatin-induced DNA damage. In a different model system, Pol beta-deficient fibroblasts were less able to repair 1,2-GG oxaliplatin adducts and were hypersensitive to oxaliplatin treatment compared with isogenic Pol beta-expressing cells. Consistent with previous studies, Pol beta-deficient mouse fibroblasts were not hypersensitive to cisplatin treatment. These data provide the first link between oxaliplatin sensitivity and DNA repair involving Pol beta. They demonstrate that Pol beta modulates the sensitivity of cells to oxaliplatin treatment.

Effect of aprotinin on renal dysfunction in patients undergoing on-pump and off-pump cardiac surgery: a retrospective observational study

BACKGROUND

Aprotinin is used during cardiac surgery for its blood-saving effects. However, reports suggest a possible association between use of this drug and increased renal dysfunction and mortality. We investigated the effect of aprotinin on renal dysfunction in cardiac surgery, considering the cofactors on-pump versus off-pump surgery and co-medication with angiotensin-converting enzyme (ACE) inhibitors.

METHODS

Our analysis included 9875 patients undergoing on-pump or off-pump cardiac surgery from Jan 1, 2000, to Sept 30, 2007. Of these patients, 9106 were included in the retrospective observational study analysis. With propensity-adjusted, multivariate staged logistic regression, we analysed separately the incidence of renal dysfunction in patients receiving aprotinin, tranexamic acid, or no antifibrinolytic treatment in the presence or absence of preoperative ACE inhibitor treatment, for both on-pump and off-pump surgical techniques.

FINDINGS

In 5434 patients undergoing on-pump cardiac surgery, the odds ratio (OR) between aprotinin and an increased risk of renal dysfunction without ACE inhibitor was 1.81 (95% CI 0.79-4.13, p=0.162) and with ACE inhibitor 1.73 (0.56-5.32, p=0.342). In the 848 patients taking ACE inhibitors and undergoing off-pump cardiac surgery, aprotinin was associated with a greater than two-fold increase in the risk of renal dysfunction after off-pump cardiac surgery (OR 2.87 [1.25-6.58], p=0.013).

INTERPRETATION

Our results have shown that aprotinin seems to be safe during on-pump cardiac surgery. However, the combination of aprotinin and ACE inhibitors during off-pump cardiac surgery is associated with a significant risk of postoperative renal dysfunction.

Long-term follow-up of ultraflex metallic stents in benign and malignant central airway obstruction

BACKGROUND

We report experience with Ultraflex metallic stents (Boston Scientific, Natick, MA) inserted at rigid bronchoscopy under general anesthesia for palliation of benign and malignant upper airway obstruction.

METHODS

Notes of all patients treated with Ultraflex stents from 1999 to 2003 were reviewed for symptomatic response, spirometric data, and any complications before discharge home. Long-term outcome was assessed by questionnaires sent to patients' general practitioners.

RESULTS

Recruited were 66 patients (12 benign, 54 malignant airway obstructions). Before discharge home, breathlessness improved in 11 of 12 patients with benign obstruction and in 39 of 54 with malignancies. Postoperative complications in 10 patients with malignant obstructions and in 2 patients with benign obstruction were successfully controlled. It was not possible to perform preoperative pulmonary function tests in most of the patients who presented as emergencies. Mean improvement in forced expiratory volume in 1 second was 0.88 liters in 3 patients with benign obstruction and 0.28 liters in 14 patients with malignant obstruction, and mean peak expiratory flow rate improved by 109 L/min and 97 L/min, respectively. General practitioners completed questionnaires for 12 benign patients and 46 of 54 patients with malignancies. At a mean follow-up of 1017 days (range, 46 to 1120 days), 10 of the 12 patients with benign disease were alive and 7 of 46 patients with malignant airway obstruction were alive, with a median survival of 128 days (mean, 361; range, 3 to 1859 days). Most survivors had Medical Research Council grade III breathlessness or better, with few stent-related symptoms.

CONCLUSIONS

Ultraflex stents proved safe and effective in prolonged palliation of benign and malignant airways obstruction.

Mapping and conformational characterization of the DNA-binding region of the breast cancer susceptibility protein BRCA1

The breast cancer susceptibility gene, BRCA1, encodes a large nuclear phosphoprotein, the major isoform of which is 1863 amino acids in size. Structure-function studies have been largely restricted to the only two domains identified by homology searches: the RING (really interesting new gene) and BRCT (BRCA1 C-terminus) domains. However, we have recently reported the identification of a large central soluble region of BRCA1 (residues 230-534) that binds specifically to four-way junction DNA, a property that potentially facilitates its role in the repair of DNA lesions by homologous recombination. We have now used a combination of limited proteolysis and extension cloning to identify more accurately the DNA-binding region of BRCA1. Limited trypsinolysis of BRCA1-(230-534) resulted in the production of a soluble domain identified as residues 230-339. However, after cloning, expression and purification of this region, studies revealed that it was unable to bind to four-way junctions, suggesting that the DNA-binding activity, in part, resides within residues 340-534. A series of fragments extending from residue 340 were produced, and each was tested for its ability to bind to four-way junction DNA in gel retardation assays. In these experiments, residues 340-554 of BRCA1 were identified as the minimal DNA-binding region. We then went on to characterize the conformation of this region using CD spectroscopy and analytical centrifugation.

Identification and purification of a soluble region in the breast cancer susceptibility protein BRCA2

The BRCA2 gene encodes a large multidomain protein of 3418 residues. Studies to elucidate the mechanisms by which BRCA2 prevents tumour formation have been largely restricted by the size of the protein. Based on secondary structure predictions we have cloned regions across the BRCA2 gene and determined the solubility of the proteins they encode. The fragment consisting of amino acids 290-456 BRCA2 was found predominantly in the soluble portion of the cell lysate and was purified by ion exchange and nickel-NTA affinity chromatography. CD spectroscopy revealed secondary structure elements consistent with a folded peptide and limited proteolysis was used to identify a potential novel domain.

Static and quasi-static calibration of a bio-MEMS device

A bio-MEMS device that has been designed to stimulate cells by oscillatory actuation in the vertical direction has been calibrated. The displacement of this device was determined experimentally by a laser interferometer when actuated by a static voltage, and by an atomic force microsope when actuated quasi-statically at 0.1 Hz. Both experimental calibrations were compared to a simple model.

Dramatic response of teratoma-associated non--germ-cell cancer with all-trans retinoic acid in a patient with nonseminomatous germ cell tumor

A patient with nonseminomatous germ cell cancer, treated with standard chemotherapy, subsequently developed a pathologically confirmed metastatic undifferentiated adenocarcinoma (non-germ-cell elements) arising from residual teratoma. Disease was present in both lobes of the liver and was deemed unresectable at the time of presentation. The patient was treated on a National Cancer Institute-sponsored institutional protocol with all-trans retinoic acid. After 60 days of oral therapy at a dose of 150 mg/m2/d (50 mg/m2 three times daily), the patient was found to have complete radiologic resolution of his hepatic metastases. He subsequently underwent surgery and his complete response was pathologically confirmed.

Long-term follow-up of a phase III study of three versus four cycles of bleomycin, etoposide, and cisplatin in favorable-prognosis germ-cell tumors: the Indian University experience

PURPOSE

In a previously reported randomized Southeastern Cancer Study Group (SECSG) trial, three cycles of chemotherapy were found to be equivalent to four cycles in patients with favorable-prognosis germ-cell cancer. We have conducted a follow-up analysis of patients treated at Indiana University (Indianapolis, IN) to compare long-term survival between the two groups and to examine factors associated with survival.

PATIENTS AND METHODS

Sixty-nine patients with minimal-stage and 49 patients with moderate-stage disseminated germ-cell tumors were randomized to either three or four courses of bleomycin, etoposide, and cisplatin (BEP) administered every 3 weeks. Median follow-up time is 10.1 years (range, 7 months to 12.6 years). Ninety-two percent of patients have an actual follow-up time of > 5 years, and 97.5% of patients have an actual follow-up time of > 3 years.

RESULTS

Survival analysis shows no significant difference between the two treatment groups in terms of overall (P = .80) or disease-free (P = .93) survival. Several clinical variables were examined by univariate analysis; only serum human chorionic gonadotropin (HCG) had an impact on survival. There were two disease-related deaths in 104 patients with HCG < or = 1,000 mIU/mL and five disease-related deaths in 14 patients with HCG greater than 1,000 mIU/mL (P < .001). Ninety-eight percent (95% CI, 95.2 to 100) of patients with favorable prognosis germ-cell tumor with an initial HCG of < or = 1,000 mIU/mL are alive without evidence of disease at 5+ years.

CONCLUSION

With long-term follow-up, there is no statistically significant difference in survival between three or four cycles of BEP chemotherapy in patients with favorable prognosis germ-cell carcinoma. Serum HCG elevation of greater than 1,000 mIU/mL is a significant predictor of poor outcome in patients with otherwise good-risk disease.

Elements for a report card: one institution's experience moving from theory to trial

The emerging computerized patient record, the movement toward a unified nursing language, and increasing accountability to the public for clinical outcomes are converging forces that require a coherent plan if nursing is to evaluate outcomes. The article describes a nursing service and school of nursing's approach and beginning experiences in identifying concepts and indicators that are useful to clinicians. These concepts and indicators have the potential to be embedded in a concurrent information system that would feed a data repository used retrospectively by clinicians and researchers. The article also discusses results to date and lessons learned.

Early effect of carotid endarterectomy on arterial blood pressure measured with an ambulatory monitor

BACKGROUND

Carotid artery disease and hypertension are associated, and carotid endarterectomy is often followed by acute changes in blood pressure. As the carotid sinus is responsible for short-term blood pressure control, occlusive carotid disease may contribute to the mechanism of preoperative hypertension.

METHODS

Ten patients undergoing carotid endarterectomy and eight having a peripheral bypass procedure were studied 2 weeks before and 2 weeks after operation, using home ambulatory blood pressure measurement.

RESULTS

A significant fall in both mean systolic (-14.4 mmHg) and mean diastolic (-12.7 mmHg) pressure was observed after carotid endarterectomy (P < 0.006), whereas no change was seen in controls.

CONCLUSION

These results suggest that there is an increase in carotid sinus activity in patients following carotid endarterectomy and supports the hypothesis that carotid sinus dysfunction contributes to hypertension in patients with carotid artery disease.

Activation of coagulation and platelets is affected by the hydrophobicity of artificial surfaces

Clot formation is a limiting factor in the use of biomaterials. We investigated the effect of surface hydrophobicity on haemostatic activation in vitro, using five polyetherurethanes of varying surface hydrophobicity (C94, C74, C54 and C34), C94 the most, and C34, the least hydrophobic, and compared them with a commercial standard pellethane. Sterilised sacks were filled with heparinised blood, rotated at 37 degrees C for 24 h and sequential samples collected into 0.103 M sodium citrate. Thrombin generation measured by thrombin-antithrombin III complexes showed a difference between the polymers at 3 h through to 6 h (P < 0.05), C94 showing the least activation and C34 the most. Factor XIIa and D-dimer levels increased between 12 (P < 0.05) and 24 h (P < 0.01) for all polyetherurethanes. The ratio of soft:hard segments (which determine hydrophobicity) of the polyetherurethanes showed a direct relationship with the degree of activation of coagulation and fibrinolysis. There was no significant increase in monocyte tissue factor expression at 5 and 105 min. Platelet function as measured by whole blood platelet aggregation showed a reduction with pellethane and C94 after 1 h using collagen, with no changes for C34, Altering surface hydrophobicity has diverse effects on haemostatic pathways, with the most hydrophobic surfaces causing least activation of coagulation but most activation of platelets.

The utility of a single sputum specimen in the diagnosis of tuberculosis. Comparison between HIV-infected and non-HIV-infected patients

STUDY OBJECTIVES

(1) To assess the utility of a single sputum specimen in the evaluation of HIV-infected patients who are suspected of having tuberculosis (TB). (2) To identify radiographic findings that discriminate between HIV-infected patients with TB and those with pneumonia of other causes.

DESIGN

Retrospective cohort analysis.

PATIENTS

All patients evaluated at Harborview Medical Center, Seattle, between January 1986 and July 1994 in whom culture of respiratory secretions grew Mycobacterium tuberculosis or Mycobacterium avium-complex. Patients who were coinfected with HIV formed the primary study group. Their chest radiographs were then compared with those of a matched group of patients with pneumonia of other causes.

MEASUREMENTS AND RESULTS

We identified 164 patients with TB, 20 of whom were HIV infected. The initial sputum specimen grew M tuberculosis in all HIV-infected patients and 99% of non-HIV-infected patients. Seventy percent of HIV-infected and 71% of non-HIV-infected patients had at least one positive smear. Most of these patients tested positive on their initial smear, and no significant difference was found between HIV-positive and HIV-negative patients (79% and 90%, respectively [p = 0.34]). The addition of a second sputum smear identified all HIV-infected patients and all but one in non-HIV-infected patients who were ultimately determined to be smear positive. A total of 27 HIV-infected patients had a positive acid-fast bacilli sputum smear during the study period, 14 of which were attributable to TB (specificity = 52%). The only radiographic findings that discriminated between HIV-infected patients with TB and those with pneumonia of other causes were the presence of cavitation or a miliary pattern (p = 0.014).

CONCLUSIONS

A single sputum specimen was sufficient to establish the diagnosis in all HIV-infected patients with pulmonary TB. A single negative sputum smear made the diagnosis of TB significantly less likely. However, a minimum of two smears were necessary to achieve an acceptable early diagnostic yield. The presenting chest radiograph failed to discriminate between HIV-infected patients with TB and pneumonia of other causes in most cases.

Missouri: Libraries and technology

The Missouri State Library was transferred from the Department of Higher Education to the Secretary of State's office in 1992. The State Library has been involved at some level in all of the technology projects and programs described in this article.

Effect of insulin on renal sodium handling in hypertensive rats

Spontaneously hypertensive rats have reduced peripheral insulin sensitivity. To determine whether hypertensive rats demonstrate reduced response to the antinatriuretic effect of insulin, urinary sodium excretion was determined in hypertensive and normotensive rats (n = 7 per group) before and during euglycemic insulin administration at two infusion rates (21 milliunits/kg load and 4 milliunits/kg/min or 85 milliunits/kg load and 8 milliunits/kg/min). Hypertensive and normotensive time controls received the vehicle for insulin administration. Mean arterial pressure was greater (p less than 0.05) and inulin clearance was less (p less than 0.05) in hypertensive than normotensive rats before insulin infusion. Baseline fractional sodium excretion was not different between groups. Low dose insulin infusion reduced (p less than 0.05) fractional sodium excretion from 0.81 +/- 0.43% to 0.31 +/- 0.07% in hypertensive rats and from 1.05 +/- 0.37% to 0.47 +/- 0.18% in normotensive rats. High dose insulin infusion reduced (p less than 0.05) fractional sodium excretion from 0.67 +/- 0.22% to 0.21 +/- 0.08% in hypertensive rats and from 0.81 +/- 0.15% to 0.30 +/- 0.09% in normotensive rats. Sodium excretion was unchanged in time controls. The reduction in sodium excretion was similar in both rat groups during low dose and high dose insulin infusions. Mean arterial pressure and inulin clearance were unchanged from baseline values during insulin infusion in all rat groups. Glucose requirement to maintain euglycemia was greater (p less than 0.05) in normotensive than hypertensive rats at both insulin infusion rates. Thus, while hypertensive rats have reduced sensitivity to the hypoglycemic effects of insulin, the antinatriuretic response to insulin is not different from that of normotensive rats.(ABSTRACT TRUNCATED AT 250 WORDS)

A theoretical approach to nursing assessment

Nurses use theory to sharpen their observations and to facilitate their understanding of the human responses to which they direct their interventions. An assessment tool, derived from the nursing theory 'modelling and role-modelling', was developed by nurses at the University of Michigan Hospitals. This tool appears to elicit the data necessary to assess and diagnose the health status of clients. This article describes the assessment tool, why it was developed, the objectives in utilization of the tool and suggestions for implementation.

Neuronal response of the hippocampal formation to injury: blood flow, glucose metabolism, and protein synthesis

The reaction of the hippocampal formation to entorhinal lesions was studied from the viewpoints of cerebral blood flow ([123I]isopropyl-iodoamphetamine[IMP])-glucose utilization ([14C]2-deoxyglucose), and protein synthesis ([14C]leucine), using single- and double-label autoradiography. Our study showed (i) decreased glucose utilization in the inner part, and increased glucose utilization in the outer part of the molecular layer of the dentate gyrus, starting 3 days after the lesion; (ii) increased uptake of [123I]IMP around the lesion from 1 to 3 days postlesion; and (iii) starting 3 days after the lesion, marked decrease in [14C]leucine incorporation into proteins and cell loss in the dorsal CA1 and dorsal subiculum in about one-half of the rats. These changes were present only in animals with lesions which invaded the ventral hippocampal formation in which axons of CA1 cells travel. By contrast, transsection of the 3rd and 4th cranial nerves resulted, 3 to 9 days after injury, in a striking increase in protein synthesis in the oculomotor and trochlear nuclei. These results raise the possibility that in some neurons the failure of central regeneration may result from the cell's inability to increase its rate of protein synthesis in response to axonal injury.

Hyperbolic geometry as an alternative to perspective for constructing drawings of visual space

It is demonstrated by the use of drawings: (i) that two-point perspective drawings based on projective geometry possess systematic distortions, and (ii) that these distortions can be eliminated in drawings based on hyperbolic geometry.

Description of a new visual illusion: a drawing of a four-dimensional cube

The visual responses evoked by an oblique projection of a four-dimensional cube are discussed and attention is drawn to the visual complexity and illusions evoked by this figure.