The proximal and distal position of the radius relative to the ulna through a full range of elbow flexion and forearm rotation.

The purpose of this study was to measure the position of the radius relative to the ulna through a complete range of elbow flexion and forearm rotation. Twenty cadaveric upper extremities were mounted on a testing jig that allowed simultaneous control of elbow flexion and forearm rotation. The longitudinal position of the radius relative to the ulna was measured using a three-dimensional digitizer at full pronation, mid-pronation (45°), neutral (0°), mid-supination (45°) and full supination at 10°, 30°, 60°, 90° and 120° of elbow flexion. Our results showed that the radius is located distally when in supination and is located more proximally as it is rotated into pronation. The longitudinal position of the radius changes over 9 mm when moving through a complete arc of forearm rotation. The angle of elbow flexion had a secondary effect on the longitudinal position of the radius, causing changes of less than 0.8 mm.

Disseminated chlorellosis in a dog.

An adult dog with ataxia and a lingual mass, previously diagnosed as protothecosis, was euthanized. At the postmortem examination, the lingual mass, regions of the lungs and hilar lymph nodes, liver, mesenteric and sublumbar lymph nodes, and spinal meninges had pronounced green discoloration. Histologically, pyogranulomatous inflammation and algal organisms were found in the tongue, spinal meninges, hilar and mesenteric lymph nodes, liver, and lung. The algae had cell walls positive for periodic acid-Schiff and cytoplasmic granules. Ultrastructurally, the algae had a well-defined cell wall, stacks of grana and thylakoid membrane, and dense bodies, typical of starch granules. The organisms were identified as Chlorella, a green alga, based on the results of histochemistical and electron microscopic examination. To the author's knowledge this is the first report of disseminated Chlorella infection and the first report in a companion animal.

The role of echocardiography in mitral valve dysfunction after repair.

The echocardiographer responsible for the intraoperative evaluation should be familiar with the transesophageal echocardiography (TEE) views of mitral valve morphology as well as the the repair procedure(s) in order to assess postoperative results. The most frequent immediate mitral valve repair failures are a result of extensive valve disease, calcification, suture dehiscence, ischemia, technical misadventures, stenosis, or systolic anterior motion. Systolic anterior motion with left ventricular outflow tract obstruction and an associated posteriorly directed jet of mitral regurgitation is the most common cause of immediate failure after mitral valve repair. The incidence of this potentially devastating complication has decreased dramatically since the introduction of preoperative measures (sliding annuloplasty and anterior leaflet valvuloplasty) in those patients at risk. Intraoperative TEE is extremely valuable in evaluating the competency of the mitral valve following repair. In fact the results of this modality have a predictive valve in determining long-term outcomes in these patients.

Determinants of influenza vaccination uptake among hospital healthcare workers.

Influenza vaccination of health care workers is recommended for their own protection and that of their patients. There is serendipitous protection for their contacts outside of work. Influenza vaccination uptake has been historically poor. A questionnaire study of healthcare staff at a tertiary referral hospital was carried out to evaluate knowledge of and attitudes to influenza and its vaccine. There was a 36% response rate to the questionnaire, but with reasonably proportionate representation of the various occupational groups. The mean acceptance of vaccine in respondents was 30%; however the vaccination rate for the hospital in 2003 was 16.2% indicating that non-vaccinees were under represented in the study sample.. Vaccine uptake increased with age. Occupationally, doctors, clerical and catering/household staff had higher than mean reported uptake of vaccine. Nurse respondents reported vaccine uptake of 22%. The role of these factors is examined in determining vaccine acceptance. A strong belief in the effectiveness of influenza vaccine was shown to be the strongest predictor of vaccine uptake with 66% of this group taking vaccine. A maximum score in an 8-question knowledge test was only associated with a 51% vaccine uptake. Implications for campaigns to improve uptake are discussed.

Proximal renal tubular acidosis.

The proximal tubule reabsorbs approximately 80% of the filtered load of bicarbonate. Defects in the process of bicarbonate reabsorption result in loss of bicarbonate and proximal renal tubular acidosis. Global proximal tubule dysfunction is known as the Fanconi's syndrome. Both isolated proximal renal tubular acidosis and the Fanconi's syndrome can result from inherited defects or can be acquired. This review will discuss the mechanisms that cause defects in proximal tubule bicarbonate transport as well as the common causes of isolated proximal renal tubular acidosis and the Fanconi syndrome.

Botulinum toxins inhibit the antidiuretic hormone (ADH)-stimulated increase in rabbit cortical collecting-tubule water Permeability.

The mammalian renal collecting duct increases its water permeability in response to antidiuretic hormone (ADH). ADH causes cytoplasmic endosomes containing the water channel, aquaporin 2 (AQP 2), to fuse with the apical membrane so that the water permeability of the tubule increases many times above baseline. SNARE proteins are involved in the docking and fusion of vesicles with the cell membrane in neuron synapses. Whether these proteins are involved in the fusion of vesicles to the cell membrane in other tissues is not entirely clear. In the present study, we examined the role of SNARE proteins in the insertion of water channels in the collecting-duct response to ADH by using botulinum toxins A, B and C. Toxins isolated from clostridium botulinum are specific proteases that cleave different SNARE proteins and inactivate them. Tubules were perfused in vitro with botulinum toxin in the perfusate (50 nM for A and B and 15 nM for C). ADH (200 pM) was then added to the bath after baseline measurements of osmotic water permeability (P(f)) and the change in P(f) was followed for one hour. Botulinum toxins significantly inhibited the maximum P(f) by approximately 50%. Botulinum toxins A and C also decreased the rate of rise of P(f). Thus, SNARE proteins are involved in the insertion of the water channels in the collecting duct.

Evaluating health impact assessment.

Health impact assessment (HIA) is a developing approach that assesses the health impacts of a proposal on a population, and produces a practical set of recommendations to inform the decision-making process of the proposal. The purpose is to influence decision makers to increase positive health impacts of a proposal and decrease negative impacts. Most work within the HIA field to date has focused on methodological development and actually carrying out HIAs. Little attention has been paid to the formal evaluation of the HIA approach and whether or not HIA works (if and how the HIA approach informs the decision-making process and, in particular, if it contributes to improving health and reducing inequalities). With the drive towards evidence-informed policy, HIA also needs to show whether it adds value to the decision-making process, given the significant resources often involved in carrying out an HIA. A suggested approach to evaluating HIAs is presented, as well as its relationship with monitoring, drawing on the significant public health evaluation literature that already exists. Methodologies appropriate for use, and examples of indicators suitable for HIA evaluation, are provided. We suggest that typical HIA evaluations should focus on the process of the HIA and the impact that it has on the decision-making process, rather than attempting to evaluate long-term health outcomes or whether predicted impacts actually occurred.

Thrombelastographic changes in OPCAB surgical patients.

The purpose of this study was to determine whether thrombelastography could detect hypercoagulability in the off-pump coronary artery bypass (OPCAB) patient. Seventeen OPCAB and six cardiopulmonary bypass (CPB) patients were studied pre- and postprocedure, as well as on each of the first three postoperative days (POD). In the OPCAB patients, there was a small reduction in the postprocedure coagulation index (CI). This was followed by an increase in the CI on each of the next three POD, reaching a level exceeding the mean preprocedure CI by 2.32 units, indicative of a state of relative hypercoagulability. The mean CI for the CPB patients decreased significantly in the postprocedure sample. Over the next 72 h, the CI increased to a level that nearly equaled the preprocedure 'baseline'. We concluded that our study identified a state of relative hypercoagulability in the OPCAB patient 72 h after surgery. The mechanism of this hypercoagulation, as well as the clinical significance of this finding, is yet to be determined.

Diffusional water permeability (PDW) of adult and neonatal rabbit renal brush border membrane vesicles.

We have shown that there is a maturational increase in osmotic water permeability (Pf) of rabbit renal brush border membrane vesicles (BBMV). The purpose of the present study was to further investigate the changes in proximal tubule water transport that occur during postnatal development. Diffusional water permeability (PDW) has not been measured directly in adult or neonatal BBMV. We validated the method described by Ye and Verkman (Simultaneous optical measurement of osmotic and diffusional water permeability in cells and liposomes. Biochemistry 28:824-829, 1989) to measure PDW in red cell ghosts and liposomes, to examine the maturational changes in PDW in BBMV. This method utilizes the sensitivity of 8-aminonaphtalene-1,3,6-trisulfonic acid (ANTS) fluorescence to the D2O-H2O content of the solvent. ANTS-loaded neonatal (11 days old) and adult BBMV were rapidly mixed with two volumes of isoosmotic D2O solution using a stopped-flow apparatus at 5 degrees -37 degrees C. PDW was lower in neonatal than adult BBMV at 5 degrees (3.77 +/- 0.34 vs. 5.35 +/- 0.43 mm/sec, respectively, p<0.05) and 20 degrees C (7.03 +/- 0.40 vs. 9.04 +/- 0.25 mm/sec, respectively, p<0.001), but was not different at 30 degrees and 37 degrees C. The activation energy (Ea) was higher in neonatal than in adult BBMV (9.29 +/- 0.56 kcal/mol vs. 6.46 +/- 0.56 kcal/mol, p<0.001). In adult BBMV, PDW was inhibited by 0.5 mM HgCl2 by 46.6 +/- 3.6%, while it was not affected in neonatal BBMV (p<0.001). The results indicate that PDW can be measured in rabbit renal BBMV. There are significant changes in water transport across the apical membrane during postnatal development, consistent with a maturational increase in channel-mediated water transport.

Creative arterial bypass grafting can be performed on the beating heart.

BACKGROUND: To demonstrate that compromise is unnecessary in either the design or performance of beating heart surgery, we report our experience, over 1 year, of total arterial revascularization where composite or creative grafting was utilized. METHODS: We performed 321 off-pump coronary artery bypass operations, of which, 290 (90%) were done with only arterial conduits. The mean number of distal anastomoses was 2.48, with a range of 1 to 5. There were no aortic anastomoses. One hundred eighty-nine patients (65%) were male, and 101 (35%) were female, with a mean age of 67 years. Comorbidities included chronic renal failure (CRF), 21 (7%); diabetes, 92 (32%); obesity, 68 (23%); hypertension, 212 (73%); chronic obstructive pulmonary disease, 189 (65%); cerebral vascular accident (CVA), 39 (13%); smoking, 164 (56%); and hypercholesterolemia, 151 (52%). The mean ejection fraction was 56%, with a range of 21% to 71%. All procedures were performed with external stabilizers with or without vacuum assist. The complete arterial revascularizations included a T-graft (internal thoracic [ITA]/radial arteries [RA]), 130 (45%); a sequential graft (ITA +/- RA), 118 (41%); a U-graft (coronary-coronary graft perfused by the ITA or right gastroepiploic artery), 5 (2%); an I-graft (ITA/RA), 4 (1%); an X-graft (ITA/RA), 2 (12); and a Y-graft (ITA/RA), 31 (10%). RESULTS: The postoperative incidence of atrial fibrillation was 80 of 290 (27%); CVA, 5 of 290 (2%); bleeding resulting in take-back, 5 of 290 (2%); CRF, 8 of 290 (3%); deep sternal infection, 4 of 290 (1%); and readmission (30-day) for angina, 4 of 290 (1%). The observed perioperative (30-day) mortality was 9 of 290 (3.1%), with the STS predicted rate of 3.82%. CONCLUSIONS: Our experience indicates that once the operating surgeon has learned to safely expose the lateral and inferior walls of the heart, the type of conduit and the method of revascularization should be no different than that used with cardiopulmonary bypass. However, we still recommend conventional methods of revascularization (on-pump with saphenous vein conduits) for the ischemic patient.

Ontogeny of rabbit proximal tubule urea permeability.

Urea transport in the proximal tubule is passive and is dependent on the epithelial permeability. The present study examined the maturation of urea permeability (P(urea)) in in vitro perfused proximal convoluted tubules (PCT) and basolateral membrane vesicles (BLMV) from rabbit renal cortex. Urea transport was lower in neonatal than adult PCT at both 37 and 25 degrees C. The PCT P(urea) was also lower in the neonates than the adults (37 degrees C: 45.4 +/- 10.8 vs. 88.5 +/- 15.2 x 10(-6) cm/s, P < 0.05; 25 degrees C: 28.5 +/- 6.9 vs. 55.3 +/- 10.4 x 10(-6) cm/s; P < 0.05). The activation energy for PCT P(urea) was not different between the neonatal and adult groups. BLMV P(urea) was determined by measuring vesicle shrinkage, due to efflux of urea, using a stop-flow instrument. Neonatal BLMV P(urea) was not different from adult BLMV P(urea) at 37 degrees C [1.14 +/- 0.05 x 10(-6) vs. 1.25 +/- 0.05 x 10(-6) cm/s; P = not significant (NS)] or 25 degrees C (0.94 +/- 0.06 vs. 1.05 +/- 0.10 x 10(-6) cm/s; P = NS). There was no effect of 250 microM phloretin, an inhibitor of the urea transporter, on P(urea) in either adult or neonatal BLMV. The activation energy for urea diffusion was also identical in the neonatal and adult BLMV. These findings in the BLMV are in contrast to the brush-border membrane vesicles (BBMV) where we have previously demonstrated that urea transport is lower in the neonate than the adult. Urea transport is lower in the neonatal proximal tubule than the adult. This is due to a lower rate of apical membrane urea transport, whereas basolateral urea transport is the same in neonates and adults. The lower P(urea) in neonatal proximal tubules may play a role in overall urea excretion and in developing and maintaining a high medullary urea concentration and thus in the ability to concentrate the urine during renal maturation.

Effect of dipyridamole on serum and urinary phosphate in X-linked hypophosphatemia.

X-linked hypophosphatemia (XLH) is characterized clinically by rickets, hypophosphatemia and hyperphosphaturia. Conventional treatment of XLH with oral phosphate and vitamin D is associated with hypercalcuria and nephrocalcinosis. Recently, intravenous and oral dipyridamole has been reported to decrease fractional excretion of phosphate in adults with idiopathic hyperphosphaturia. Our objective was to determine whether oral dipyridamole therapy reduces urinary phosphate excretion and increases serum phosphate concentration in children with XLH. A prospective study was performed in six children with XLH. The average age of the patients at the start of the study was 12.5+/-1.0 years. The effects of 12 weeks of oral dipyridamole therapy, at 4.4+/-0.4 mg/kg body weight per day, on serum phosphorous, parathyroid hormone (PTH), 1,25 (OH)2 vitamin D, osteocalcin, tubular maximum for phosphate reabsorption (TmP/GFR), urinary calcium excretion, and cyclic adenosine 3',5'-monophosphate (cAMP) excretion, were compared to baseline levels. Our results show that there was no change in serum phosphorous concentration or TmP/GFR after 12 weeks of dipyridamole therapy. Dipyridamole therapy also had no effect on serum PTH, serum 1,25 (OH)2 vitamin D, alkaline phosphatase, osteocalcin levels, urinary calcium or cAMP excretion. We therefore concluded that in children with XLH, a 12-week course of dipyridamole had no effect on serum phosphorous or its urinary excretion. Dipyridamole therapy is unlikely to improve the bone disease in children with XLH.

Rapid removal of vancomycin by continuous veno-venous hemofiltration.

We describe a 14-year-old girl with staphylococcal (coagulase-negative) ventriculo-peritoneal shunt infection, who developed oliguric acute renal failure and was found to have a serum vancomycin concentration of 250 microg/ml. Since only about 10%-50% of vancomycin is bound to protein in blood, we employed continuous veno-venous hemofiltration (CVVH) with a high ultrafiltration rate (1,800 ml/h) for increased convective clearance to remove vancomycin, which may have contributed to the acute renal failure. At the end of 38 h of CVVH, the vancomycin concentration had decreased in an exponential manner to 27 microg/ml. Over the subsequent 3-4 days, her renal function improved and the vancomycin concentration decreased further to <5 microg/ml. In conclusion, we believe that a high serum vancomycin concentration may be nephrotoxic and demonstrate that CVVH can be used effectively to remove vancomycin in children with acute renal failure.

Effects of 20-HETE and 19(S)-HETE on rabbit proximal straight tubule volume transport.

The kidney has the highest abundance of cytochrome P-450 of all extrahepatic organs. Within the kidney, the highest concentration of cytochrome P-450 is found in the proximal tubule. Whether 20- or 19(S)-hydroxyeicosatetraenoic acid (HETE), the major P-450 metabolites of arachidonic acid in the proximal tubule, affect transport in this segment has not been previously investigated. We examined the direct effects of 20- and 19(S)-HETE on volume absorption (J(v)) in the rabbit proximal straight tubule (PST). Production of 20-HETE by rabbit PST was demonstrated by incubating microdissected tubules with [(3)H]arachidonic acid and separating the lipid extract by HPLC. There was significant conversion of [(3)H]arachidonic acid to 20-HETE in control tubules that was inhibited by 10(-5) M N-methylsulfonyl-12,12-dibromododec-11-enamide (DDMS). Addition of exogenous 20-HETE had no effect on PST volume transport. However, inhibition of endogenous production of 20-HETE using DDMS stimulated transport. In the presence of DDMS, 20-HETE inhibited PST J(v). 19(S)-HETE in the bathing solution stimulated PST J(v) alone and in the presence of DDMS. Thus omega- and omega-1-hydroxylase products of arachidonic acid have direct effects on PST transport. Endogenous production of 20-HETE may play a role in tonic suppression of transport and may therefore be an endogenous regulator of transport in the proximal tubule.

Maturation of proximal straight tubule NaCl transport: role of thyroid hormone.

We have recently demonstrated that the rates of both active and passive proximal straight tubule (PST) NaCl transport in neonatal rabbits were less than in adults. In this segment NaCl entry across the apical membrane is via parallel Na(+)/H(+) and Cl(-)/OH(-) exchangers, which increases in activity with maturation. The present in vitro microperfusion study examined whether thyroid hormone plays a role in the maturational increase in PST NaCl transport. Neonatal and adult PST were perfused with a high-chloride-low bicarbonate solution without organic solutes, simulating late proximal tubule fluid. Thyroid hormone-treated neonates had a higher rate of PST total and passive NaCl transport. In 8-wk-old animals that were hypothyroid since birth, the maturational increase in total and passive NaCl transport was prevented. Thyroid treatment for 4 days in hypothyroid 8-wk-old rabbits increased the rate of both total and passive NaCl transport. The maturational increases in both Na(+)/H(+) and Cl(-)/OH(-) exchange activities were blunted in 8-wk-old hypothyroid animals and increased to control levels with thyroid treatment. This study demonstrates that thyroid hormone is a factor responsible for the maturational increase in both active and passive PST NaCl transport.

Maturational changes in rabbit renal basolateral membrane vesicle osmotic water permeability.

We have recently demonstrated that while the osmotic water permeability (Pf) of neonatal proximal tubules is higher than that of adult tubules, the Pf of brushborder membrane vesicles from neonatal rabbits is lower than that of adults. The present study examined developmental changes in the water transport characteristics of proximal tubule basolateral membranes by determining aquaporin 1 (AQP1) protein abundance and the Pf in neonatal (10-14 days old) and adult rabbit renal basolateral membrane vesicles (BLMV). At 25 degrees C the Pf of neonatal BLMV was significantly lower than the adult BLMV at osmotic gradients ranging from 40 to 160 mOsm/kg water. The activation energies for osmotic water movement were identical in the neonatal and adult BLMV (8.65 +/- 0.47 vs. 8.86 +/- 1.35 kcal x deg(-1) x mol(-1). Reflection coefficients for sodium chloride and sodium bicarbonate were identical in both the neonatal and adult BLMV and were not different from one. Mercury chloride (0.5 mM) reduced osmotic water movement by 31.3 +/- 5.5% in the adult BLMV, but by only 4.0 +/- 4.0% in neonatal vesicles (P < 0.01). Adult BLMV AQP1 abundance was higher than that in the neonate. These data demonstrate that neonatal BLMV have a lower Pf and AQP1 protein abundance than adults and that a significantly greater fraction of water traverses the basolateral membrane lipid bilayer and not water channels in neonates compared to adults. The lower Pf of the neonatal BLMV indicates that the basolateral membrane is not responsible for the higher transepithelial Pf in the neonatal proximal tubule.

Anatomic lung resections using minimally invasive thoracic surgery (MITS).

We have designed a minimally invasive thoracic surgery (MITS), which, in this report, we compare to the conventional muscle-sparing thoracotomy (MST). We retrospectively compared 70 consecutive MITS patients (mean age, 65 years) and 70 consecutive MST patients (mean age, 60 years) who underwent thoracotomies for similar pathologies between 1995 and 1997. All comparisons between the MITS and MST groups were made using the Student's t-test. Extubation times, intensive care unit (ICU) stays, analgesia requirements, morbidities/mortalities, hospital lengths of stay (LOS), and cost analyses were all compared. Nine of the 70 planned MITS procedures were converted intraoperatively to MST. All nine of these patients were admitted to the ICU. All of the MST patients spent a minimum of 24 hours in the ICU. The mean LOS in the MITS group was 2.87 days with a mean hospital cost of 6,480.00 dollars, while in the MST group it was 8.28 days (P = 0.003) and 11,490.00 dollars (P = 0.006). There were no deaths and 6 complications in the MITS series. There were two mortalities and 15 complications in the MST patients. Our MITS procedure not only may be performed with low morbidity and cost, it also allows early ambulation and early hospital discharge.

Digital fluoroscopic assessment of the scapulohumeral rhythm.

Previous studies have shown that abnormal rotation of the scapula is associated with shoulder pathology. Among the methods which have been proposed, planar x-ray measurements are probably the only methods, which enable clinicians to assess accurately and objectively the scapulohumeral function in vivo. The aim of this study was to develop a method for the assessment of scapulohumeral kinematics using digital fluoroscopy. Anteroposterior images of the right glenohumeral joint were taken, in thirty-four healthy males, with the arm at rest, 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees and maximum abduction, in the scapular plane. High inter- and intra-examiner reliability was observed regarding the arm and scapular angle measurements (ICC = 0.92-0.99). The positioning of the arm at the proposed angles was also highly accurate (< 2.3 degrees misplacement) and reproducible (CV% < 5.3%). The mean radiation dose was 0.075 mSv (+/- 0.027 mSv). At the resting position the scapula was in slight downward rotation (-2.4 degrees +/- 4.3 degrees) and the arm in slight abduction (1.5 degrees +/- 6.6 degrees). The mean maximum scapular rotation and the mean maximum arm abduction was 61.4 degrees (+/- 5.2 degrees) and 162.4 degrees (+/- 6.6 degrees) respectively. A curvilinear relationship was found between the arm angle (AA) and the scapular angle (SA) (p < 0.0001). The AA:SA ratio for the entire range of abduction was 2.5:1. The greatest contribution of the scapula (1.7:1) achieved at 30 degrees-60 degrees of arm. The high accuracy and reliability of our method and the low radiation recordings suggests that digital fluoroscopy may be considered for further investigation of the scapulohumeral kinematics in both healthy and pathological shoulders.