Diverticular colovesical fistula: What should we really be doing?

BACKGROUND: Colovesical fistula secondary to diverticular disease is increasing in incidence. Presentation and severity may differ, but a common management strategy may be applied. The aim of this study is to evaluate the characteristics and perioperative management of patients with colovesical fistulae and determine optimal management. METHODS: From 2003 to 2012, all charts of surgical patients with diverticular colovesical fistulae at two different institutions were reviewed. Patient and presentation characteristics and perioperative management and outcomes were recorded. Patient groups with early and late catheter removal (< 8 and ≥ 8 days) were compared with significance level set at p < 0.05. RESULTS: Seventy-eight patient charts were reviewed. The mean duration of symptoms was 7.5 months. Laparoscopic assisted surgery was carried out in 35% of patients. Complex bladder repair was performed in 27%. Mean length of stay was 8 days. Mean urinary catheter duration was 13 days. Seventy percent of patients underwent postoperative cystogram, with 4% positive for extravasation. Patients with early catheter removal were significantly older, more likely to have received intraoperative methylene blue instillation, and less likely to have had a complex bladder repair (p < 0.05). Complication rate, length of stay, postoperative cystography, and stent use were similar for both catheter removal groups. CONCLUSIONS: Intraoperative methylene blue bladder instillation should be utilized to limit unnecessary bladder repairs. In the setting of negative methylene blue extravasation, surgeons may confidently remove urinary catheters in 7 days or less, in some cases as early as 48 h. In complex bladder repairs, cystogram is still an important adjunct, with those patients with negative studies benefiting from catheter removal at 7 days or less.

Cholangitis and Cholangiohepatitis in Dogs: A Descriptive Study of 54 Cases Based on Histopathologic Diagnosis (2004-2014).

BACKGROUND: Cholangitis in dogs appears to be more common than previously thought, but understanding of the disease remains incomplete. OBJECTIVE: To describe a population of dogs with cholangitis or cholangiohepatitis. ANIMALS: Fifty-four client-owned dogs with cholangitis or cholangiohepatitis. METHODS: Medical records of dogs with cholangitis or cholangiohepatitis confirmed by histopathology between January 2004 and December 2014 were identified using a computer-based search and retrospectively reviewed. RESULTS: Clinical signs included vomiting (72.2%), lethargy (70.4%), and inappetence (64.8%). Most dogs (49/50) had increased liver enzyme activities, hyperbilirubinemia (32/50), and hypercholesterolemia (24/43). Ultrasonographic abnormalities of the hepatobiliary system were seen in 84% of cases. On histopathology, 53 of 54 affected dogs had neutrophilic cholangitis (NC) or cholangiohepatitis, whereas 1 dog had lymphocytic cholangitis. Most cases (42/54) were chronic. Evidence of concurrent biliary disease (46.2%) and biliary tract obstruction (42.6%) was common. Seventeen of 36 biliary and 11 of 25 liver cultures were positive for bacterial growth; Escherichia coli and Enterococcus spp. were most common. Median patient survival was 671 days (95% confidence interval [CI]: 114-1,426). On Cox regression, dogs that did not have a cholecystectomy performed had a 2.1 greater hazard for death (P = 0.037; 95% CI: 1.0-4.3) compared to cholecystectomized dogs. Dogs >13 years old had a 5.0 greater hazard for death (P = 0.001; 95% CI: 1.9-13.2) compared to younger dogs. CONCLUSIONS AND CLINICAL SIGNIFICANCE: Chronic NC or cholangiohepatitis was most common. Cholecystitis and biliary tract obstruction often occurred in conjunction with cholangitis. Cholecystectomized dogs had decreased risk of death; thus, cholecystectomy may improve patient outcome.

A systematic review of methods to predict maximal oxygen uptake from submaximal, open circuit spirometry in healthy adults.

OBJECTIVES: This systematic review aimed to (i) report the accuracy of submaximal exercise-based predictive equations that incorporate oxygen uptake (measured via open circuit spirometry) to predict maximal oxygen uptake (VO2max) and (ii) provide a critical reflection of the data to inform health professionals and researchers when selecting a prediction equation. DESIGN: Systematic review. METHODS: A systematic search of MEDLINE, EMBASE (via OvidSP), CINAHL, SPORTDiscus (via EBSCO Host) and Scopus databases was undertaken in February 2013. Studies were required to report data on healthy participants aged 18-65y. Following tabulation of extracted data, a narrative synthesis was conducted. RESULTS: From a total of 7597 articles screened, 19 studies were included, from which a total of 43 prediction equations were extracted. No significant difference was reported between the measured and predicted VO2max in 28 equations. Pearson's correlation coefficient between the predicted and measured VO2max ranged from r=0.92 to r=0.57. The variables most commonly used in predictive equations were heart rate (n=19) and rating of perceived exertion (n=24). CONCLUSIONS: Overall, submaximal exercise-based equations using open circuit spirometry to predict VO2max are moderately to highly accurate. The heart rate and rating of perceived exertion methods of predicting VO2max were of similar accuracy. Important factors to consider when selecting a predictive equation include: the level of exertion required; participant medical conditions or medications; the validation population; mode of ergometry; time and resources available for familiarisation trials; and the level of bias of the study from which equations are derived.

The perceptually regulated exercise test is sensitive to increases in maximal oxygen uptake.

The aim of this study was to assess the sensitivity of a perceptually regulated exercise test (PRET) to predict maximal oxygen uptake (VO2max) following an aerobic exercise-training programme. Sedentary volunteers were assigned to either a training (TG n = 16) or control (CG n = 10) group. The TG performed 30 min of treadmill exercise, regulated at 13 on the Borg Rating of Perceived Exertion (RPE) Scale, 3× per week for 8 weeks. All participants completed a 12-min PRET to predict VO2max followed by a graded exercise test (GXT) to measure VO2max before and after training. The PRET required participants to control the speed and incline on the treadmill to correspond to RPE intensities of 9, 11, 13 and 15. Predictive accuracy of extrapolation end-points RPE19 and RPE20 from a submaximal RPE range of 9-15 was compared. Measured VO2max increased by 17 % (p < 0.05) from baseline to post-intervention in TG. This was reflected by a similar change in [VO2max predicted from PRET when extrapolated to RPE 19 (baseline VO2max: 31.3 ± 5.5, 30.3 ± 9.5 mL kg(-1) min(-1); post-intervention VO2max: 36.7 ± 6.4, 37.4 ± 7.9 mL kg(-1) min(-1), for measured and predicted values, respectively). There was no change in CG (measured vs. predicted VO2max: 39.3 ± 6.5; 40.3 ± 8.2 and 39.2 ± 7.0; 37.7 ± 6.0 mL kg(-1) min(-1)) at baseline and post-intervention, respectively. The results confirm that PRET is sensitive to increases in VO2max following aerobic training.

The influence of spasmolytic agents on heart rate variability and gastrointestinal motility in normal horses.

The effects of hyoscine-N-butylbromide (hyoscine) and propantheline-bromide (propantheline) on heart rate (HR), HR variability (HRV) and gastrointestinal tract (GIT) contractions in the normal horse were determined. Five adult horses had ECG recordings for 180 min after treatment with propantheline (100mg), hyoscine (120 mg) or saline. Both propantheline and hyoscine reduced GIT sounds, with propantheline having a longer duration of effect (≥120 min). Both drugs elevated HR relative to the control baseline period (P<0.05), with the effects of propantheline again being of longer duration. HRV analysis indicated that propantheline suppressed Total Power (P<0.05), and both the high frequency (HF) and low frequency (LF) components of the power spectral analysis for up to 60-90 min post treatment. Hyoscine had no effect on HRV Total Power but reduced the HF component for 30 min after drug injection. Time domain variables correlated with Total Power and HF data (P<0.01). The marked effect of these compounds on parasympathetic control of cardiac and GIT function in normal horses should be taken into consideration when evaluating a clinical response to these agents.

Adiposity and plane of nutrition influence reproductive neuroendocrine and appetite responses to intracerebroventricular insulin and neuropeptide-Y in sheep.

Long-term nutritional background is thought to influence hypothalamic appetite and reproductive neuroendocrine responses to short-term nutritional feedback. In order to investigate this phenomenon, the effects of intracerebroventricular administration of insulin or neuropeptide-Y (NPY) on LH secretion and voluntary food intake (VFI) were examined in sheep that were initially thin and kept on an increasing nutritional plane (INP), or initially fat and kept on a decreasing nutritional plane (DNP), for 10 weeks. Intracerebroventricular insulin stimulated LH secretion and suppressed VFI in INP sheep when initially thin, but not when they became fat, and had no effect on LH in DNP sheep when initially fat, and stimulated LH secretion when they became thin. Intracerebroventricular NPY had no effect on LH or VFI in INP sheep when initially thin, decreased LH secretion and increased VFI when they became fat, and decreased LH secretion in DNP sheep when initially fat but had no effect when they became thin. Therefore, sensitivity to insulin increases with low or decreasing nutritional status and decreases with high or increasing nutritional status, whereas sensitivity to NPY increases with high or increasing nutritional status and decreases with low or decreasing nutritional status. In conclusion, reproductive neuroendocrine and appetite responses to acute changes in nutritional feedback signals depend on the individual's longer-term nutritional background.

Left ventricular torsion in primary chronic mitral regurgitation.

BACKGROUND: Torsion is essential for normal systolic and diastolic function of the left ventricle (LV), and is known to be abnormal in animal models of mitral regurgitation (MR). There are no comparable data in humans. OBJECTIVES: To study LV torsion in humans with chronic primary MR using speckle-tracking echocardiography. METHODS: Rotation and rotation rate were measured from two-dimensional (2D) greyscale LV base and apex short-axis images by speckle-tracking echocardiography in 38 patients and 30 controls. Using custom software, plots of torsion against time were constructed by deducting base rotation from apex rotation. Loops of torsion against LV radial/longitudinal displacement and volume were automatically plotted. RESULTS: Peak systolic torsion, systolic torsional velocity and untwisting velocity were similar in the two groups. In controls, untwisting started 23 ms before aortic valve closure but was delayed in MR to 15 ms after aortic valve closure, p<0.001. In normal subjects there was rapid untwisting during isovolumic relaxation, with minimal expansion of the LV radial and longitudinal axes. In MR, early untwisting rate was decreased, with less untwisting for a given volume increase. Extensive LV remodelling and worsening MR were associated with progressive reductions in systolic torsion and untwisting velocity, and progressive delay in the onset of untwisting. CONCLUSIONS: Chronic MR results in significant delay and slowing of LV untwisting, such that early untwisting is coupled with chamber expansion. Correlations between disease severity and torsional parameters suggest a potential role of these variables in assessing early signs of ventricular dysfunction.

Otoliths developed in microgravity.

Little is known about mechanisms that regulate the development of the otoliths in the gravity-sensing organs. Several reported experiments suggest that the growth of the otoliths is adjusted to produce a test mass of the appropriate weight. If this is the case, larger than normal otoliths would be expected in animals reared in reduced gravity and a reduced mass, relative to 1-g controls, would be expected in animals reared at elevated g. In gastropod mollusks, the gravity-sensing organ is the statocyst, a spherical organ whose wall is made largely of sensory receptor cells with motile cilia facing the lumen. Dense statoconia in the cyst lumen interact with cilia of receptor cells at the bottom of the cyst and action potentials in their axons carry information on direction and magnitude of gravity and linear acceleration. In the marine mollusk, Aplysia californica, larvae reared at 2 to 5-g, the volume of statoconia was reduced in a graded manner, compared to 1-g control animals. In the statocyst of the fresh-water pond snail, Biomphalaria glabrata, reared in space in the Closed Equilibrated Biological Aquatic System (CEBAS), the number and total volume of statoconia was increased approximately 50%, relative to ground-reared controls. Lychakov found the utricular otolith to be 30% larger in space-reared Xenopus, whereas we found the saccular otolith to be significantly larger in newt larvae reared in space. In cichlid fish reared on a centrifuge, the saccular otolith was smaller than in 1-g controls. Here, we demonstrate that the otoliths of late-stage embryos of the swordtail fish, Xiphophorus helleri, reared in space on STS-89 and STS-90 (Neurolab) were significantly larger than those of ground-controls reared in functionally identical hardware.

Cold-evoked pain varies with skin type and cooling rate: a psychophysical study in humans.

The psychophysical responses to noxious cold stimulation of the skin in normal human subjects are not well understood. Continuous pain ratings with the visual analogue scale is an important method to assess these responses. In this study, we addressed several important issues about the parameters with which stimuli are delivered: the type of skin stimulated, the rate with which the stimulus temperature decreases, and the dimension of the pain rated by subjects. Cold stimuli were delivered to the thenar eminence (glabrous skin) and the dorso-lateral hand (hairy skin) via a 4 cm(2) Peltier-type stimulator. Cold and pain thresholds were determined by the method of limits (MOL). A computerized visual analogue scale (VAS) was used to obtain continuous ratings of pain intensity and affect. The McGill Pain Questionnaire (MPQ) was used to assess the quality of cold-evoked pain. Supra-threshold stimuli (34 degrees C base) were delivered at 0.5, 1 or 2 degrees C/s to 2 degrees C, held for 20s and returned to baseline at 9 degrees C/s. These studies revealed: (1) Cold thresholds, measured with MOL, were lower (i.e. occurred at higher absolute temperatures) for the hairy skin of the dorso-lateral hand compared to the glabrous skin of the thenar eminence. (2) A similar pattern was evident for cold induced pain thresholds with MOL at 1.5 degrees C/s and with intensity and affect VAS scales at 0.5 and 1 degrees C/s. (3) Exponents for supra-threshold ratings fit to power functions were larger for the glabrous skin site than the hairy skin site regardless of cooling rate or dimension of pain measured. (4) All pain indices were higher for slower cooling rates. (5) No significant differences were found in the pain indices for pain ratings of intensity and affect. (6) A substantial proportion of subjects chose words representing paradoxical heat with the MPQ. (7) Painful paradoxical heat sensations occurred most often during cooling, while innocuous warm sensations mainly occurred during the rewarming phase.

Endoscopic ultrasound for diagnosis and staging of pancreatic tumors.

Endoscopic ultrasound (EUS) is proving to be a useful tool for evaluation of clinically suspected pancreatic masses unsatisfactorily evaluated by other means of imaging. We reviewed the records of 19 patients who had CT and EUS performed for clinically suspected pancreatic masses. Each patient had subsequent surgical exploration. Nineteen patients (11 females and 8 males) presenting with symptoms (11 with obstructive jaundice, 6 with abdominal pain and weight loss) or incidental CT findings suspicious for pancreatic carcinoma underwent EUS for further pancreatic evaluation. All of these patients had exploratory laparotomies, with 13 pancreaticoduodenectomies, 3 distal pancreatectomies and splenectomies, 1 bypass procedure, 1 open pancreatic and hepatic biopsy showing metastatic disease, and 1 open exploration with negative fine-needle aspiration biopsy. EUS correctly identified pancreatic neoplasms in 17 of 19 cases, with two false positives. The tumors included 15 adenocarcinomas, 1 microcystic adenoma, and 1 lymphoma. Node status was correctly predicted in 9 of 12 specimens. Nine of 12 tumors had accurate tumor staging by EUS. Absence of vascular invasion was accurately predicted in 13 of 14 cases. Two patients had metastatic disease discovered at laparotomy. All 19 patients had preoperative abdominal CT scans, with six of these negative for pancreatic masses. EUS is more sensitive than CT in detecting pancreatic masses and is more accurate than CT in locally staging pancreatic tumors. This higher sensitivity is important because those patients with earlier stage tumors are the most likely to benefit from resection.

Development of the endolymphatic sac and duct in the Japanese red-bellied newt, Cynops pyrrhogaster.

The development and maturation of the endolymphatic sac (ES) and duct (ED) were studied in the newt Cynops pyrrhogaster. The ES first appears as an oval capsule at the dorsal-medial tip of the otic vesicle at stage 39, about 11 days after oviposition. The ES consists of polymorphous epithelial cells with a minimum of cytoplasm. The intercellular space (IS) between the epithelial cells is narrow and has a smooth surface. At stage 44, the size of the ES increases as many vacuoles in the IS become filled. At stage 46, 18 days after oviposition, the ES elongates markedly and a slit-like lumen is found in the ES. The epithelium contains a few cell organelles which are scattered in the cytoplasm. The vacuoles in the IS are fused, which expands the IS. Two days later (stage 48), floccular material (endolymph) is present in the expanded lumen. The IS dilates and has a wide and irregular appearance. At stage 50, approximately 26 days after oviposition, the ES extends and expands significantly and crystals (otoconia) can now be seen in the widened lumen of the ES. The cytoplasm of the cuboidal epithelial cells contains an abundance of vesicles surrounded by ribosomes and Golgi complexes. Intercellular digitations are formed in the expanded IS. At stage 54, the ES forms a large bellow-like pouch. Numerous otoconia accumulate in the lumen. Free floating cells and cell debris can be seen in the lumen at this stage. The epithelial cells contain numerous cytoplasmic organelles which are evenly distributed in the cytoplasm. Granules are found in the apical and lateral cytoplasm. The IS is loose and displays a labyrinthine appearance. The primitive ED first appears as a connection between the ES and the saccule but no lumen is present inside at stage 39. At stage 46, a narrow lumen is formed in the ED, which corresponds to the formation of the ES lumen. At stage 50, as the ED extends, floccular material is seen in the lumen. At stage 54, the ED bears numerous microvilli on its luminal surface. Otoconia and endolymph are present in the ED. Tight junctions between the epithelial cells are formed at stage 46. A fully developed intercellular junctional complex is produced at stage 54. Based on the development of the ES and ED, the maturation of function of the ES and ED are discussed.

Evidence for the involvement of carbonic anhydrase and urease in calcium carbonate formation in the gravity-sensing organ of Aplysia californica.

To better understand the mechanisms that could modulate the formation of otoconia, calcium carbonate granules in the inner ear of vertebrate species, we examined statoconia formation in the gravity-sensing organ, the statocyst, of the gastropod mollusk Aplysia californica using an in vitro organ culture model. We determined the type of calcium carbonate present in the statoconia and investigated the role of carbonic anhydrase (CA) and urease in regulating statocyst pH as well as the role of protein synthesis and urease in statoconia production and homeostasis in vitro. The type of mineral present in statoconia was found to be aragonitic calcium carbonate. When the CA inhibitor, acetazolamide (AZ), was added to cultures of statocysts, the pH initially (30 min) increased and then decreased. The urease inhibitor, acetohydroxamic acid (AHA), decreased statocyst pH. Simultaneous addition of AZ and AHA caused a decrease in pH. Inhibition of urease activity also reduced total statoconia number, but had no effect on statoconia volume. Inhibition of protein synthesis reduced statoconia production and increased statoconia volume. In a previous study, inhibition of CA was shown to decrease statoconia production. Taken together, these data show that urease and CA play a role in regulating statocyst pH and the formation and maintenance of statoconia. CA produces carbonate ion for calcium carbonate formation and urease neutralizes the acid formed due to CA action, by production of ammonia.

Development of gravity-sensing organs in altered gravity conditions: opposite conclusions from an amphibian and a molluscan preparation.

NASA: Researchers examined early otolith development in microgravity using fertilized eggs of the Japanese newt, Cynops pyrrhogaster in space flight. Ground experiments examined statocyst, embryonic statolith volume, and statoconia in the post-metamorphic marine mollusk Aplysia californica reared at 1-g and 2-5.7-g. Results indicate that exposure to hypergravity decreased the otolith mass to compensate for increased weight in Aplysia. In the Cynops, there was no compensatory difference in otolith mass, though otoconia production in the endolymphatic system was enhanced.^ieng

Development of gravity-sensing organs in altered gravity.

Experiments are described in which the development of the gravity-sensing organs was studied in newt larvae reared in microgravity on the IML-2 mission and in Aplysia embryos and larvae reared on a centrifuge at 1 to 5 g. In Aplysia embryos, the statolith (single dense mass on which gravity and linear acceleration act) was reduced in size in a graded fashion at increasing g. In early post-metamorphic Aplysia or even in isolated statocysts from such animals, the number of statoconia produced is reduced at high g. Newt larvae launched before any of the otoconia were formed and reared for 15 days in microgravity had nearly adult labyrinths at the end of the IML-2 mission. The otoliths of the saccule and utricle were the same size in flight and ground-reared larvae. However, the system of aragonitic otoconia produced in the endolymphatic sac in amphibians was much larger and developed earlier in the flight-reared larvae. At later developmental stages, the aragonitic otoconia enter and fill the saccule. One flight-reared larva was maintained for nine months post-flight and the size of the saccular otolith, as well as the volume of otoconia within the endolymphatic sac, were considerably larger than in age-matched, ground-reared newts. This suggests that rearing in microgravity initiates a process that continues for several months after introduction to 1-g, which greatly increases the volume of otoconia. The flight-reared animal had abnormal posture, pointing its head upward, whereas normal ground-reared newts always keep their head horizontal. This suggests that rearing for even a short period in microgravity can have lasting functional consequences in an animal subsequently reared in 1-g conditions on Earth.

Modulation by food restriction of intracellular calcium signaling in parotid acinar cells of aging Fischer 344 rats.

Previous studies suggest that alpha 1-adrenergic (alpha 1-AR)-induced intracellular calcium ([Ca2+]i) mobilization in rat parotid acinar cells declines with age. In this study, we examined the effects of food restriction on alpha 1-AR and muscarinic-stimulated [Ca2+]i mobilization in parotid acinar cells during aging. [Ca2+]i levels in response to the alpha 1-AR agonist epinephrine and the muscarinic agonist carbachol were evaluated in Fura-2-loaded parotid acinar cells from ad libitum-fed (AL) and food-restricted (FR) Fischer 344 male rats at 4, 6, 14, and 24 months of age. [Ca2+]i responses to epinephrine and carbachol (10 microM) were significantly reduced (48% and 35%, respectively; p < .05) in cells from 24-month-old AL rats as compared to younger AL rats. In contrast, no significant reduction of epinephrine and carbachol responses was observed in 24-month-old FR animals. An age-related increase in basal [Ca2+]i (peak around 14 months; p < .02) was observed in both AL and FR rats. In addition, basal [Ca2+]i was higher in FR than in AL rats at 14 and 24 months of age (p < .02). These studies suggest that FR partially attenuates or delays age-related impairments in alpha 1-AR- and muscarinic-cholinergic signal transduction systems of parotid acinar cells. Basal [Ca2+]i also appears to be altered during aging and by FR.