New classification and update on the quinolone antibiotics.

The newer fluoroquinolones have broad-spectrum bactericidal activity, excellent oral bioavailability, good tissue penetration and favorable safety and tolerability profiles. A new four-generation classification of the quinolone drugs takes into account the expanded antimicrobial spectrum of the more recently introduced fluoroquinolones and their clinical indications. First-generation drugs (e.g., nalidixic acid) achieve minimal serum levels. Second-generation quinolones (e.g., ciprofloxacin) have increased gram-negative and systemic activity. Third-generation drugs (e.g., levofloxacin) have expanded activity against gram-positive bacteria and atypical pathogens. Fourth-generation quinolone drugs (currently only trovafloxacin) add significant activity against anaerobes. The quinolones can be differentiated within classes based on their pharmacokinetic properties. The new classification can help family physicians prescribe these drugs appropriately.

Changing practices in the use of pneumococcal vaccine.

BACKGROUND AND OBJECTIVES: An important issue facing primary care practices is how to best improve preventive services to patients. We sought to determine if an intervention designed by a continuous quality improvement (CQI) process (reminder sticker and patient education sign in each examining room) or a patient education intervention (sign only) could increase the rate of pneumococcal vaccination. METHODS: These two interventions were administered over a 6-month period in a controlled, prospective study design in a family practice residency program clinic. The study targeted patients ages 65 and older and patients ages 2-64 with diabetes mellitus who had never received the pneumococcal vaccine. The main outcome measure was the vaccination rate in the targeted population. RESULTS: A total of 1,647 patient encounters involving 778 patients were documented during the study period. Overall, the reminder and sign module had higher percentages of pneumococcal vaccination in this target population (20% versus 11% for sign only, versus 7% control). Chi-square analysis revealed a statistically significant difference for this group, compared with placebo, but not for the sign-only group. CONCLUSIONS: An intervention designed from a CQI process to impact the office patterns of primary care physicians can produce measurable changes in pneumococcal vaccination rates.

Assessment of the quality of neonatal echocardiographic images transmitted by ISDN telephone lines.

OBJECTIVE: To assess the quality of echocardiographic images from neonates transmitted over Integrated Service Digital Network 2 (ISDN2) channels. DESIGN: Echocardiographic images were viewed live in real time either by a direct video link or by transmission over the commercial network, using one, two, or three ISDN2 channels. The order of the viewing formats was random and four observers marked each view for potential for provision of complete diagnostic information and quality. SETTING: Cardiology department of tertiary referral centre for paediatric cardiac services. ISDN lines were positioned in two nearby rooms. Telephone connection was through the commercial network and video connection by a direct video cable. PATIENTS: 10 neonates were studied (weight 2600 to 3900 g). In each, nine echocardiographic studies were undertaken to assess imaging (M mode and cross sectional) and Doppler (spectral and colour) quality. RESULTS: No significant differences were found in diagnostic ability between the different formats for M mode, colour, or spectral Doppler studies. For cross sectional imaging the diagnostic information and image quality increased with increasing numbers of ISDN channels. With six channels there was little difference from the directly connected images. CONCLUSIONS: In echocardiographic assessment of the newborn, one or two ISDN2 channels will transmit images of satisfactory quality in many situations but three or more channels are necessary to ensure minimum degradation of the live image.

The action of local anaesthetics on the compound action potential is altered by the nature of the permeant ion in frog nerve.

Compound action potentials were recorded from the isolated frog sciatic nerve using either sodium or lithium as the permeant ion, and an assessment of the action of local anaesthetics was made. The compound action potentials evoked from the nerve were not different in terms of their mean amplitude or time to peak whether recorded with sodium or lithium as the permeant ion. The local anaesthetics tested, procaine, lignocaine and benzocaine, were more potent, as measured by their IC50 values, by 2.3, 2.1 and 1.8 times, respectively, when lithium rather than sodium was used as the permeant ion. The sensitivity of the nerves to tetrodotoxin was not significantly different whether sodium or lithium was used as the permeant ion. The slope of the concentration inhibition curves was not significantly altered in the presence of sodium or lithium for any of the compounds tested. These results are consistent with the idea that the binding site for local anaesthetics is intimately associated with the pore region of the channel and that the nature of the permeant ion can alter the interaction of the drugs with the sodium channel. However, since this is not a common feature of all compounds which block sodium channels by interacting at the pore, it may help refine the existing structural models of sodium channels.

In vitro microbiological characterization of novel macrolide CP-163,505 for animal health specific use.

A novel 16-membered-ring macrolide agent (CP-163,505, a reductive amination derivative of repromicin) was identified as an antibacterial against Pasteurella haemolytica, P. multocida and Actinobacillus pleuropneumoniae, important etiological agents of livestock respiratory disease. In vitro MIC50/90 analysis revealed that CP-163,505 was more potent (4x) than tilmicosin against P. multocida, and equivalent to tilmicosin against P. haemolytica and A. pleuropneumoniae. In time kill kinetic studies, CP-163,505 showed bactericidal activity against P. haemolytica, P. multocida and A. pleuropneumoniae and bacteriostatic activity against E. coli at 8 times its MIC. In vitro, CP-163,505 was more potent in alkaline pH (16 approximately 32 x ) and less potent in the presence of excess cations (Mg+2 and Ca+2, 4x). EDTA and PMBN increased CP-163,505 potency against E. coli (4x) but not against the other species. Similar results were obtained with erythromycin A and tilmicosin, which were used as controls. From our data, we hypothesize that Pasteurella and Actinobacillus have an outer membrane significantly different from that of the typical enteric Gram-negative bacterium E. coli.

Management of hospitalized patients with type 2 diabetes mellitus.

Subopitmal glycemic control in hospitalized patients with type 2 (non-insulin-dependent) diabetes mellitus can have adverse consequences, including increased neurologic ischemia, delayed wound healing and an increased infection rate. Poor glycemic control can also affect the outcome of the primary illness. If possible, hospitalized diabetic patients should continue their previous antihyperglycemic treatment regimen. Decreased physical activity and the stress of illness often lead to hyperglycemia in hospitalized patients with type 2 diabetes. When indicated, insulin is given either as a supplement to usual therapy or as a temporary substitute. The overall benefit of the traditional sliding-scale insulin regimen has been questioned. Insulin supplementation given according to an algorithm may be a logical alternative. Any antihyperglycemic regimen should be administered and monitored in a manner coincident with the intake of food or other sources of calories. Factors that can alter glycemic control acutely, including specific medical conditions and medications, should be identified and anticipated.

Interdisciplinary rural health training for health professional students: strategies for curriculum design.

Interdisciplinary rural health program offer a promising solution to the challenge of preparing graduates for rural practice, with the ultimate goal of promoting better health care for rural populations. This article focuses on the three-year experience of a model interdisciplinary rural health curriculum implemented in eastern North Carolina. Ten strategies are presented as a framework for the design and implementation of an effective practice-based curriculum for interdisciplinary rural health training. Allied health educators should examine existing curriculum models to build upon their strengths and explore new models to meet evolving delivery system and consumer needs.

Lipid and lipoprotein responses to oral combined hormone replacement therapy in normolipemic obese women with controlled type 2 diabetes mellitus.

This study investigated the effects of oral combined hormone replacement therapy (OCHRT) on lipid concentrations and subpopulation distribution of lipoproteins in nine postmenopausal women with type 2 diabetes mellitus and moderate glycemic control. After 16 weeks of continuous daily therapy of conjugated estrogens 0.625 mg and medroxyprogesterone 2.5 mg, the mean concentration of high-density lipoprotein (HDL) cholesterol showed a statistically significant increase of 16.7%, predominantly in the HDL2 subfraction. No statistically significant changes in mean concentrations of total cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, very low-density lipoprotein (VLDL) triglycerides, apolipoprotein A1, or apolipoprotein B were evident. Likewise, no changes were found in the average diameter of VLDL, LDL, or HDL particles; triglyceride concentrations of VLDL subfractions; cholesterol concentrations of LDL subfractions; or chemical composition of plasma LDL. These findings lend further support to the use of OCHRT in postmenopausal women with diabetes to decrease their risk for coronary artery disease.

Intermittent ductal patency in healthy newborn infants: demonstration by colour Doppler flow mapping.

Colour Doppler flow mapping was used to determine the time of closure of the arterial duct in 51 healthy newborn infants. Initial time of closure corresponded with previous reports: 20% on the first day, 82% by the second day, 96% by the third day, and 100% by the fourth day. Twenty infants were delivered by caesarean section and followed up for seven days even if the duct had apparently closed; in six intermittent patency was demonstrated with flow in the third, fourth or fifth day, although earlier functional closure had been observed. All were found to be closed on the sixth and seventh days. It is necessary to be aware of the phenomenon of intermittent closure in any study determining or assessing the effect of any intervention on ductal patency.

Electrocardiographic changes during cesarean section under regional anesthesia.

To determine electrocardiographic changes and whether myocardial ischemia occurs during cesarean section, electrocardiograms were recorded continuously using Holter monitoring in 25 patients undergoing elective cesarean section under either spinal or epidural anesthesia. In addition, in 13 of the patients, two-dimensional precordial echocardiography was carried out before and during cesarean section. ST segment depression suggestive of myocardial ischemia occurred in 16 patients including 8 of the 13 with echocardiograms. Wall motion remained entirely normal during episodes of ST segment depression. Patients in whom ST depression developed had significantly more rapid heart rates at delivery than those who did not experience ST depression. We conclude that ST segment depression is a common feature of the electrocardiogram during cesarean section under regional anesthesia and is not the result of myocardial ischemia.

Quality of life in long-term geriatric care: the dietitian's role.

The dietitian plays a leadership role in improving the quality of life of nursing home residents. A better understanding of this role can strengthen practice in this area. This paper attempts to define the role of the dietitian in the nutritional care of the elderly in long-term care facilities. The impact of poor appetites, extended stays and nutrient requirements on menu planning and recipe development are discussed. Resident empowerment, improvement of the dining environment, evaluation of eating skills, and eating rehabilitation are proposed as new roles for the dietitian in the promotion of food consumption. The characteristics of nutritional assessment and therapeutic diets as they relate to long-term geriatric care are discussed.

Influence of colour Doppler echocardiography on the ultrasonic assessment of congenital heart disease: a prospective study.

OBJECTIVE: To evaluate the additional information provided by colour Doppler in the ultrasonic assessment of congenital heart disease. PATIENTS AND METHODS: A prospective study of 215 children (age range 1 day-16 years) presenting with clinical signs of congenital heart disease. RESULTS: Colour Doppler was essential for the diagnosis of an anomalous left coronary artery and altered the management of a patient initially diagnosed as having cardiomyopathy. Colour Doppler provided extra information, but without major impact on management, in the following: the diagnosis of ventricular septal defects associated with other defects, of multiple ventricular septal defects, of anomalous pulmonary venous drainage, and of mild mitral regurgitation; the demonstration of site of coarctation, of stenotic or hypoplastic pulmonary artery branches, of unobstructed flow through a right atrial membrane, and of left ventricle to right atrium regurgitation; the assessment of the width of the duct and of flow through the patent foramen ovale in transposition and tricuspid atresia; the differentiation of pulmonary atresia from critical pulmonary stenosis and the measurement of maximum velocity of tricuspid regurgitation. CONCLUSIONS: Ideally all patients should undergo colour Doppler studies before cardiac surgery to ensure a more accurate diagnosis. However, since the additional information provided does not affect the management in most patients, machines without colour Doppler can provide a satisfactory service in paediatric cardiology centres in countries where resources are limited.

Balloon atrial septostomy under echocardiographic control: six years' experience and evaluation of the practicability of cannulation via the umbilical vein.

Balloon atrial septostomy was undertaken under cross sectional echocardiographic control in 63 consecutive infants: in no case was fluoroscopic imaging required. The procedure was performed in the cardiac catheterisation laboratory, ward side room, or at the bedside in the neonatal intensive care unit. Catheterisation via the umbilical vein was attempted in 37 infants aged less than 48 hours old and was successful in 27. No complication was clearly attributable to the procedure though two infants died. A nine day old child died from disseminated intravascular coagulation the day after septostomy by the iliofemoral route and another, aged nine days, died of necrotising enterocolitis which had developed when he was eight days old, after umbilical catheterisation at eight hours. Balloon atrial septostomy is a safe and easy procedure under cross sectional echocardiographic imaging control. Catheterisation via the umbilical vein was safe, easy to perform, and is appropriate in infants aged less than 48 hours.

A conceptual framework for dietetics.

The model for the practice of dietetics recently adopted by the CDA board of directors clarifies how the different facets of dietetics are interrelated and part of a common definition of dietetics. It is our hope that this discussion will help us to move beyond the question of identity we often feel in our profession and will stimulate debate and the development and testing of alternate models; this should further clarify the essence of dietetic practice and enable us to continue to improve our unique and common contribution towards the provision of quality nutritional care to the population.

Anomalous origin of the left coronary artery from the pulmonary trunk: elucidation with colour Doppler flow mapping.

Four infants and children with anomalous connection of the left coronary artery to the pulmonary trunk were studied with colour Doppler flow mapping. In three the diagnosis was only suspected when the colour Doppler study showed dilated intraseptal and epicardial vessels and an abnormal flow signal into the pulmonary artery in diastole; this latter signal localised the exact site of communication, which was not apparent on angiocardiography. Two of these patients had previously had operations for severe mitral regurgitation, the diagnosis of anomalous left coronary artery having been previously considered in one but missed despite aortic root angiography. The colour study in the fourth was largely confirmatory, operation without catheterisation being undertaken on the basis of the echocardiographic images. By contrast in two infants subsequently seen with congestive cardiomyopathy the demonstration of flow direction in the left coronary artery confirmed that it was normally connected to the aorta. Colour Doppler flow mapping can show flow direction in the left coronary artery and from the mouth of an anomalous coronary artery into the pulmonary artery, thus simplifying the diagnosis and allowing the site of the connection of the left coronary artery to the pulmonary artery to be determined with precision.

Congenital fistula between the left ventricle and coronary sinus: elucidation by colour Doppler flow mapping.

A fistula between the left ventricle and the coronary sinus was diagnosed by Doppler echocardiography and confirmed by cardiac catheterisation in a symptom free child who presented with clinical signs of mitral regurgitation. A similar abnormality has been reported after repeated mitral valve replacement and after myocardial infarction but a congenital fistula of this type has not been described before.

Variability of the Doppler gradient in pulmonary valve stenosis before and after balloon dilatation.

The variability of the valve gradient measured by Doppler in pulmonary stenosis was compared with the variability of the gradient measured at catheterisation in 42 infants and children undergoing catheterisation with a view to balloon dilatation of the pulmonary valve. The maximum value measured by Doppler when the patient was unsedated was significantly higher than that measured when the patient was sedated for catheterisation, and the maximum gradient was significantly higher shortly after than several days later. In a patient with pronounced infundibular obstruction after dilatation the Doppler signal clearly showed that the obstruction was dynamic, with a superimposed lower fixed signal that correctly predicted the final low gradient. The Doppler gradient in an alert and unsedated patient may be a better measure of the true physiological value. The highest Doppler value so obtained is a more appropriate indicator of the need for balloon dilatation than a single catheter measurement. The result of dilatation is best assessed by Doppler measurement at least a day after the procedure.

The use of sweat to monitor lead absorption through the skin.

It is usually assumed that lead can be absorbed through the skin only if it is present as an organolead compound such as tetraethyllead or lead naphthanate. It has been found, however, that finely-powdered lead metal or lead nitrate solution placed on the skin results in rapid absorption of lead, and transport of the metal around the body. The absorbed lead appears in sweat and saliva, but not in blood or urine. The application of 6 mg of lead as 0.5 M lead nitrate to the left arm resulted in an increase in lead concentration in pilocarpine-induced iontophoresis sweat samples taken from the right arm, from an initial value of 15-25 micrograms Pbl-1 to greater than 300 micrograms Pbl-1 after 2 days. Saliva lead increased from 2.5 to 15 micrograms Pbl-1 in the same period. The rate of lead absorption through the skin increases with increased sweating of the skin. Since no measurable increase in blood lead has been found, the lead must be transported in the plasma and rapidly concentrated into the extracellular fluid pool (sweat and saliva), without significant uptake by the erythrocytes, and with a very low transient concentration in the plasma. Workers occupationally exposed to lead have extremely high levels of lead in sweat even though their lead in blood is only moderately elevated. Lead absorbed through the skin may be eliminated via sweat and other extracellular fluids, and hence not be as great a health hazard as ingested lead, but this will need to be proved by further studies.