Primary-care-based randomised placebo-controlled trial of antibiotic treatment in acute maxillary sinusitis

BACKGROUND: The value of antibiotics in acute rhinosinusitis is uncertain. Although maxillary sinusitis is commonly diagnosed and treated in general practice, no effectiveness studies have been done on unselected primary-care patients. We used a randomised, placebo-controlled design to test the hypothesis that there would be an improvement associated with amoxycillin treatment for acute maxillary sinusitis patients presenting to general practice. METHODS: Adult patients with suspected acute maxillary sinusitis were referred by general practitioners for radiographs of the maxillary sinus. Those with radiographic abnormalities (n = 214) were randomly assigned treatment with amoxycillin (750 mg three times daily for 7 days; n = 108) or placebo (n = 106). Clinical course was assessed after 1 week and 2 weeks, and reported relapses and complications were recorded during the following year. FINDINGS: After 2 weeks, symptoms had improved substantially or disappeared in 83% of patients in the study group and 77% of patients taking placebo. Amoxycillin did not influence the clinical course of maxillary sinusitis nor the frequency of relapses during the 1-year follow-up. Radiographs had no prognostic value, nor were they an effect modifier. Side-effects were recorded in 28% of patients given amoxycillin and in 9% of those taking placebo (p < 0.01). The occurrence of relapses was similar in both groups (21 vs 17%) during the follow-up year. INTERPRETATION: Antibiotic treatment did not improve the clinical course of acute maxillary sinusitis presenting to general practice. For these patients, an initial radiographic examination is not necessary and initial management can be limited to symptomatic treatment. Whether antibiotics are necessary in more severe cases warrants further study.     

Primary bidirectional superior cavopulmonary shunt in infants between 1 and 4 months of age

The performance of a primary bidirectional superior cavopulmonary shunt procedure in early infancy is attractive because it minimizes the number of operations needed before a Fontan procedure, avoids ventricular volume overload and its sequelae, and eliminates pulmonary artery distortion. However, concerns over elevated or labile pulmonary vascular resistance have limited its use in the first few months of life. Nine patients aged 1 to 4 months (5 patients, < 2 months) have undergone a primary bidirectional superior cavopulmonary shunt procedure between October 1992 and March 1994. Primary diagnoses were tricuspid atresia (n = 4), asplenia syndrome (n = 2), polysplenia syndrome (n = 1), double-outlet right ventricle (n = 1), and double-inlet left ventricle (n = 1). Associated lesions of immediate surgical importance were total anomalous pulmonary veins (n = 2), a restrictive atrial septum (n = 4), bilateral superior venae cavae (n = 5), and patent ductus arteriosus (n = 5). The surgical procedure consisted of unilateral (n = 4) or bilateral (n = 5) bidirectional superior cavopulmonary shunt and the repair of associated lesions. Of significance, in 4 of our first 5 patients a very limited additional source of pulmonary blood flow was provided because of a low arterial oxygen tension immediately after cardiopulmonary bypass. Pleural effusions developed in 2 of these 4 patients. In subsequent patients cardiopulmonary bypass was not used whenever possible or, if it was needed, use of an extra source of pulmonary blood flow was avoided.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hexon-only binding of VP26 reflects differences between the hexon and penton conformations of VP5, the major capsid protein of herpes simplex virus

VP26 is a 12-kDa capsid protein of herpes simplex virus 1. Although VP26 is dispensable for assembly, the native capsid (a T=16 icosahedron) contains 900 copies: six on each of the 150 hexons of VP5 (149 kDa) but none on the 12 VP5 pentons at its vertices. We have investigated this interaction by expressing VP26 in Escherichia coli and studying the properties of the purified protein in solution and its binding to capsids. Circular dichroism spectroscopy reveals that the conformation of purified VP26 consists mainly of beta-sheets (approximately 80%), with a small alpha-helical component (approximately 15%). Its state of association was determined by analytical ultracentrifugation to be a reversible monomer-dimer equilibrium, with a dissociation constant of approximately 2 x 10(-5) M. Bacterially expressed VP26 binds to capsids in the normal amount, as determined by quantitative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cryoelectron microscopy shows that the protein occupies its usual sites on hexons but does not bind to pentons, even when available in 100-fold molar excess. Quasi-equivalence requires that penton VP5 must differ in conformation from hexon VP5: our data show that in mature capsids, this difference is sufficiently pronounced to abrogate its ability to bind VP26.     

Metabolic efficiency during arm and leg exercise at the same relative intensities

This study was conducted to compare gross efficiency (GE), net efficiency (NE), work efficiency (WE), and delta efficiency (DE) between arm crank and cycle exercise at the same relative intensities. Eight college-aged males underwent two experimental trials presented in a randomized counterbalanced order. During each trial subjects performed three intermittent 7-min exercise bouts separated by 10-min rest intervals on an arm or semirecumbent leg ergometer. The power outputs for the three bouts of arm crank or cycle exercise corresponded to 50, 60, and 70% of the mode-specific VO2peak. GE, NE, and WE were determined as the ratio of Kcal.min-1 equivalent of power output to Kcal.min-1 of total energy expended, energy expended above rest and energy expended above unloaded exercise, respectively. DE was determined as the ratio of the increment of Kcal.min-1 of power output above the previous lower intensity to the increment of kcal.min-1 of total energy expended above the previous lower intensity. GE and NE did not differ between arm crank and cycle exercises. However, WE was lower (P < 0.05) during arm crank than cycle exercise at 50, 60, and 70% VO2peak. DE was also lower (P < 0.05) during arm crank than cycle exercise at delta 50-60 and at delta 60-70% VO2peak. It is concluded metabolic efficiency as determined by work and delta efficiency indices was lower during arm crank compared with cycle exercise at the same relative intensities. These findings add to the understanding of the difference in metabolic efficiency between upper and lower body exercise.     

Development of a pediatric burn pain and anxiety management program

To facilitate effective management of pain and anxiety, and to permit more objective assessment of changes in this management, a pain and anxiety guideline was developed and has been followed uniformly for 3 years. The guideline describes four patient care categories: (1) ventilated acute, (2) nonventilated acute, (3) chronic acute, and (4) reconstructive. A small and consistent formulary was emphasized. A specific guideline for background, procedural, and transition pain and anxiety management was developed for each patient care category. All pain and anxiety medications given to all acutely burned children admitted to the Institute for 12 consecutive months were recorded, and daily pain and anxiety discomfort scores were noted using a 5-level action-based bedside scoring system. Doses of individual pain and anxiety medications were calculated as mg per kg per patient-day in each category, and all doses were found to be within guideline specifications. The efficacy of the guideline was judged by four discomfort scores: (1) background pain, (2) procedural pain, (3) background anxiety, and (4) procedural anxiety, and were adequate in all patient categories. There were no complications related to overmedication experienced during the interval. Our objective was to develop a guideline for pain and anxiety management that: (1) was safe and effective over a broad range of ages and injury acuities seen in the unit, (2) was explicit in its recommendations, (3) had a limited formulary to optimize staff familiarity with agents used, and (4) took advantage of the presence of a bedside nurse to continuously evaluate efficacy and intervene when needed through dose-ranging. Although many drugs are appropriate, our choices were based on institutional familiarity and simplicity. This process of developing a clear and consistent guideline can be duplicated in any unit.     

Isolated left superior vena cava to the left atrium with situs solitus and dextrocardia: extracardiac repair facilitated by juxtaposition of the atrial appendages

We describe an extremely unusual case, with isolated left superior vena cava to the left atrium, normal intracardiac anatomy, and left juxtaposition of the atrial appendages. Surgical repair was performed without cardiopulmonary bypass by anastomosing the left superior cava to the superior aspect of the right atrial appendage, and was facilitated by the ectopic location of the appendage.     

Genetic variants of human T-lymphotrophic virus type II in American Indian groups

The human T-lymphotropic virus type II (HTLV-II) is found in many New World Indian groups in North and South America and may have entered the New World from Asia with the earliest migration of ancestral Amerindians over 15,000 years ago. To characterize the phylogenetic relationships of HTLV-II strains infecting geographically diverse Indian populations, we used polymerase chain reaction to amplify HTLV-II sequences from lymphocytes of seropositive Amerindians from Brazil (Kraho, Kayapo, and Kaxuyana), Panama (Guaymi), and the United States (the Navajo and Pueblo tribes of the southwestern states and the Seminoles of Florida). Sequence analysis of a 780-base pair fragment (located between the env gene and the second exons of tax/rex) revealed that Amerindian viruses clustered in the same two genetic subtypes (IIa and IIb) previously identified for viruses from intravenous drug users. Most infected North and Central American Indians had subtype IIb, while HTLV-II infected members of three remote Amazonian tribes clustered as a distinct group within subtype IIa. These findings suggest that the ancestral Amerindians migrating to the New World brought at least two genetic subtypes, IIa and IIb. Because HTLV-II strains from Amazonian Indians form a distinct group within subtype HTLV-IIa, these Brazilian tribes are unlikely to be the source of IIa viruses in North American drug users. Finally, the near identity of viral sequences from geographically diverse populations indicate that HTLV-II is a very ancient virus of man.