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Predictors of a successful outcome of serial electrophysiologic (EP) and drug studies have been identified from among baseline patient characteristics but not from among measures of baseline and drug-related EP effects. Identifying such predictors would be useful in explaining the mechanism of successful drug therapy and in guiding drug development and selection. We prospectively studied EP characteristics in 159 trials in 62 patients with ventricular tachycardia or ventricular fibrillation during antiarrhythmic therapy and compared EP measures between successful (n = 30) and failed trials (n = 129). The average age of the patients was 64 years (range 27 to 78 years); 82% were men and 18% women; and 87% had coronary artery disease. Measurements included R-R, QRS, and QT intervals during intrinsic rhythm and during pacing at cycle lengths of 600 of 400 msec; ventricular effective refractory periods (ERP) during pacing at cycle lengths of 600 and 400 msec; and changes in these measures, comparing treatment with drug-free baseline. Univariate predictors of success (in order of significance) included ERP 600 QRS 600 , sotalol versus other drugs, ERP 400 QRS 400 , ΔERP600, ΔR-R, ERP600, QRS400 (negative association), ΔERP400, QRS600 (negative association), ERP400 (all p ERP 600 QRS 600 (p = 0.01) in the first model and ERP 400 QRS 400 (p = 0.01) in the second model were significantly and independently associated with achieving noninducibility with drug therapy. Therefore measures of greater refractoriness and lesser delays in conduction velocity (ie, greater “wavelength”) relate to drug success. These observations may assist in new drug development and, with other predictors, in drug selection for the treatment of patients.

Implantable cardioverter-defibrillators (ICDs) are being used increasingly for treatment of malignant ventricular tachyarriuythmias. However, ICD discharge is associated with significant morbidity. Antiarrhythmic therapy could reduce the frequency of ICD discharge, but its effect is uncertain. Thus, the effect of antiarrhythmic therapy was evaluated in a randomized trial. Thirty-four patients (32 men and 2 women, average age 60 years) who received an ICD for sustained ventricular tachyoardia or fibrillation were entered in the trial and randomized to the best “drug” therapy (group 1; n = 17) or no therapy (group 2; n = 17). After the first ICD discharge, patients were to be crossed over to the alternative treatment arm. Twenty-nine patients had coronary artery disease. The induced arrhythmia was ventricular tachyoardia in 33 patients and ventricular fibrillation in 1. Ejection fraction averaged 39%. The 2 groups were well balanced, without differences in demographic variables. In group 1, class I therapy was given to 9 patients and class III to 9. Beta blockade was used in a similar number of patients in groups 1 and 2 (n = 8 and 6, respectively). Time to the first shock or the end of follow-up averaged 143 days (range 1 to 609). During follow-up, 21 patients had a first ICD discharge event (11 in group 1, and 10 in group 2; p = 0.72). Event-free survival in each group was assessed by the Kaplan-Meier method, using the intention-to-treat approach. Overall median time to the first event was 134 days. Time to the first event did not differ between groups (p = 0.66; log-rank test). The effect of drug therapy versus no therapy was also compared in 13 patients who underwent crossover treatment. In the crossover analysis, event-free survival was also similar for the 2 treatment arms (p = 0.51; log-rank test). Individual responses in 6 patients showed substantial (greater than threefold) differences in time to the discharge event between treatment arms, which favored the drug in 4 and no drug in 2 (p = NS). The results of this initial randomized experience do not support routine, adjunctive antiarrhythmic therapy for the purpose of extending the time to ICD discharge. Additional and larger studies are indicated. It is recommended currently that the use of antiarrhythmic drugs in the setting of ICD therapy should be based on individual patient needs.

The effects of lip bumper treatment on the mandibular arch were observed in 32 patients with late transitional and early permanent dentitions. Dental cast measurements were made for arch perimeter, arch length, and arch width. Cephalometric radiographs were used to determine labial tipping of the incisors and distal movement of the molars. Arch circumference increased in all patients, ranging from 0.7 mm to 8.8 mm, with an average of 4.1 mm. The mean increase in arch length was 1.2 mm and was largely attributed to anterior tipping of the mandibular incisors. Change in arch length was the most predictive variable for the increase in arch circumference. Passive changes in arch width were recorded, with a mean increase of 2.0 mm in the intercanine distance and 2.5 mm in the first premolar distance. Arch width increments contributed to the increase in arch circumference, but the increases in arch width were not found to be predictive of the change in arch circumference. Changes in either arch circumference or arch length were not related to the duration of treatment, age and sex of the patient, or the eruption status of the permanent second molars.

This chapter outlines the procedures necessary to provide protection from radiation for workers in the field of X-ray crystallography. The suggestions are based on the requirements currently in force in the UK as embodied in the Approved Code of Practice, Ionising Radiations Regulations 1985 (IRR’ 85)1. Although the legal requirements in other countries may differ slightly from the above, the basic principles are relevant to all situations.

This paper explores the nature of strategic goals underlying composite information systems (CIS) and ways to increase their likelihood of success. It studies a major regional hospital and its relat...

The north-east coast of Australia is fronted by the world's longest coral reef system, which stretches in a north/south direction between latitudes 9° and 24° South. Although its outer limit is at distances of between 20 and 120 miles from the coast the enclosed waters are relatively shallow and contain many islands, detached reefs and shoals. The shipping lane between the coast and the Great Barrier Reef is known as the Inner Route. Torres Strait, its northern entrance, although extensive is shallow throughout and encumbered by reefs and islands to such an extent that only one route through it has been lit. The alternative routes are shallow or tortuous.

The title complex KF·(CH2CO2H)2, grown from aqueous solution, is orthorhombic, space group Pnam, with a= 7.0680(1), b= 5.5710(1), c= 16.846(2)A, and Z= 4. Its structure, determined by X-ray diffraction techniques and refined to R 0.035, consists of infinite chains of fluoride ions joined to two succinic acid molecules by very short hydrogen bonds of R(O ⋯ F)= 2.441(3)A. The complex [F(HCO2H)2]– has been used as a model for the purpose of ab initio calculations on this doubly hydrogen-bonded fluoride, and these show a theoretical hydrogen-bond energy of 179 kJ mol–1 for each bond. The i.r. spectrum of KF·(CH2CO2H)2 shows eight very broad bands in several regions of the spectrum and these are assigned to the vibrational modes of this unique O–H ⋯ F–⋯ H–O hydrogen-bonded system.

Two cases of ventriculitis with Staphylococcus epidermidis that failed on therapy with an antistaphylococcal penicillin are presented. Both infections responded to a combination of intravenous and intraventricular vancomycin and rifampin. Vancomycin and rifampin represent an important antibiotic regimen for the management of resistant infections of the central nervous system, especially with those due to S. epidermidis or methicillin-resistant Staphylococcus aureus.

Cranioectodermal dysplasia (CED) is a disorder characterized by craniofacial, skeletal, and ectodermal abnormalities. Most cases reported to date are sporadic, but a few familial cases support an autosomal-recessive inheritance pattern. Aiming at the elucidation of the genetic basis of CED, we collected 13 patients with CED symptoms from 12 independent families. In one family with consanguineous parents two siblings were affected, permitting linkage analysis and homozygosity mapping. This revealed a single region of homozygosity with a significant LOD score (3.57) on chromosome 3q21-3q24. By sequencing candidate genes from this interval we found a homozygous missense mutation in the IFT122 (WDR10) gene that cosegregated with the disease. Examination of IFT122 in our patient cohort revealed one additional homozygous missense change in the patient from a second consanguineous family. In addition, we found compound heterozygosity for a donor splice-site change and a missense change in one sporadic patient. All mutations were absent in 340 control chromosomes. Because IFT122 plays an important role in the assembly and maintenance of eukaryotic cilia, we investigated patient fibroblasts and found significantly reduced frequency and length of primary cilia as compared to controls. Furthermore, we transiently knocked down ift122 in zebrafish embryos and observed the typical phenotype found in other models of ciliopathies. Because not all of our patients harbored mutations in IFT122, CED seems to be genetically heterogeneous. Still, by identifying CED as a ciliary disorder, our study suggests that the causative mutations in the unresolved cases most likely affect primary cilia function too.

The crystal structure of the red form of [(2,2′-bipyridyl)PtCl2] has been determined from X-ray diffractometer data. Crystals are orthorhombic, space group Cmcm, with a= 17·666(2), b= 9·086(1), c= 6·803(1)A, Z= 4. The structure was derived from 554 intensities, by Patterson and Fourier methods, and refined by least squares to R 0·024. The structure comprises layers of monomeric molecules lying parallel to (001) and separated by 3·40 A. The platinum atoms are nearly superimposed and are separated by 3·45 A. There is marked pleochroism, the maximum absorption of the broad line at 520 nm occurring when the electric vector is parallel to the strings of platinum atoms.Unit-cell parameters for the yellow form are a= 15·93, b= 7·22, c= 18·38 A; space group Pbca, Z= 8.

A test method is described which will reveal some common distortions in the scanning electron microscope. The test will give a measure of resolution and also a measure of signal-to-noise ratio at the display console.

The title complex KF·(CH2CO2H)2, grown from aqueous solution, is orthorhombic, space group Pnam, with a= 7.0680(1), b= 5.5710(1), c= 16.846(2)A, and Z= 4. Its structure, determined by X-ray diffraction techniques and refined to R 0.035, consists of infinite chains of fluoride ions joined to two succinic acid molecules by very short hydrogen bonds of R(O ⋯ F)= 2.441(3)A. The complex [F(HCO2H)2]– has been used as a model for the purpose of ab initio calculations on this doubly hydrogen-bonded fluoride, and these show a theoretical hydrogen-bond energy of 179 kJ mol–1 for each bond. The i.r. spectrum of KF·(CH2CO2H)2 shows eight very broad bands in several regions of the spectrum and these are assigned to the vibrational modes of this unique O–H ⋯ F–⋯ H–O hydrogen-bonded system.

Cerebrospinal fluid (CSF) shunt infections represent a difficult clinical problem which usually requires removal of the foreign body along with appropriate antimicrobial therapy. Staphylococcus epidermidis is the most common organism isolated from infected CSF shunts. Antimicrobial resistance to S. epidermidis, which may not be reliably predicted by routine laboratory testing, has become an increasingly important problem in the management of these patients. We report two patients with S. epidermidis ventriculitis that persisted on anti-staphylococcal therapy and subsequently responded to Vancomycin and Rifampin. The first patient was a 9-year-old girl with post-traumatic ventricular hemorrhage requring a ventriculostomy catheter. The catheter became infected with S. epidermidis which persisted despite removal of the foreign body and intravenous (IV) Nafcillin. She subsequently responded to IV Vancomycin, oral Rifampin and intraventricular Vancomycin injections (via a reservoir).

In an analysis, by both crystallographic and microbiological methods, of 50 urinary calculi recently removed by surgical operation, 33 proved to be of metabolic origin (mostly calcium oxalate and some uric acid or urate) and 17 of ‘infective’ origin (struvite, apatite or a mixture of the two). Metabolic stones were usually bacteriologically sterile or contained only small numbers (< 103/g of stone) of bacteria which did not produce urease, while infective stones always contained urease-producing organisms, usually Proteus mirabilis, in large numbers (> 105/g). The combined approach of stone analysis by crystallography and microbiological culture yields more information than conventional techniques on which to base the treatment of urinary calculi and the prevention of their recurrence.

X-ray diffraction crystallography was used to determine the crystalline composition of 18 equine urinary calculi, including stones originating in the kidney, bladder and urethra. Calcium carbonate in the form of calcite was found to be the major component in all calculi examined. Other components commonly found included weddellite and substituted vaterite. Urine deposits from a number of normal horses were also examined. The significance of these findings, as well as those from a number of previous reports, are discussed in relation to the possible aetiology of urolithiasis in the horse.

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