Functional magnetic resonance imaging in conscious animals: a new tool in behavioural neuroscience research.
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Animals↗
Biomedical subjects
P Kulkarni
Publications and source records attributed to P Kulkarni.
Antifungal antibiotics.
The search for new drugs against fungal infections is a major challenge to current research in mycotic diseases. The present article reviews the current types of antifungal infections, the current scenario of antifungal antibiotics, and the need and approaches to search for newer antifungal antibiotics and antifungal drug targets.
Antifungal Agents↗
Review: uveitis and immunosuppressive drugs.
Uveitis, inflammation of the eye, is a common occurring disease resulting from a wide variety of traumatic and immunogenic insults and, in most cases, can be treated successfully by corticosteroids. However, corticosteroids have severe side effects. Alternative therapy is using nonsteroidal anti-inflammatory agents like indomethecin, diclofenac and flurbiprofen. The uveitic cases are prominent in the third world countries, and many of the patients are not responsive or become refractory to steroidal or nonsteroidal therapy. Therefore, there is another class of compounds "immunosuppressive drugs" found to be successful in treating uveitis. These include cyclosporin A, tacrolimus, and sirolimus. However, being immunosuppressive they also have side effects. Therefore, the effective therapy with lower side effects is the treatment with combination of these drugs in lower dosages. Cyclosporin A plus sirolimus or tacrolimus in threshold doses alleviate signs of uveitis with lower incidence of side effects.
Animals↗
Effect of inner cannula removal on the work of breathing imposed by tracheostomy tubes: a bench study.
BACKGROUND: Tracheotomy has been used to assist in weaning patients from mechanical ventilation. Some patients fail to be weaned from the ventilator despite tracheostomy. We hypothesized that removing the inner cannula from the tracheostomy tube would decrease the tube's imposed work of breathing (WOB(IMP)). METHODS: The hypothesis was tested using a lung model, by measuring the change in WOB(IMP) when the inner cannula was removed. A mechanical lung model was developed using a test lung to simulate a spontaneously breathing patient. WOB(IMP) was measured with a commercially available lung mechanics monitor. Shiley size 6, 8, and 10 nonfenestrated tracheostomy tubes were tested with the inner cannula in and out. Breathing conditions were simulated using tidal volumes (V(T)) of 300 and 500 mL matched with breathing frequencies of 12, 24, and 32 breaths per minute, by using a ventilator to simulate spontaneous breathing through one side of the test lung. RESULTS: Under all the tested breathing conditions, WOB(IMP) for each of the 3 tracheostomy tubes was significantly reduced (p < 0.05) when the inner cannula was removed. Also, as simulated spontaneous inspiratory flow demand increased (ie, as V(T) and/or frequency were increased), WOB(IMP) also increased, and vice versa. With the cannula removed, WOB(IMP) was not significantly different between the size 6 and 8 tubes nor between the size 8 and 10 tubes when V(T) was 300 mL and frequency was 12 breaths per minute. CONCLUSIONS: There was a significant decrease in WOB(IMP) with each tube when the inner cannula was removed. WOB(IMP) increased with an increase in inspiratory flow demand (ie, increase in V(T) and/or frequency), as well as when tube size decreased. In weaning a tracheostomized patient from mechanical ventilation, increasing the internal diameter of the tube by removing the inner cannula may be beneficial. Further study is needed to determine if these findings are clinically important.
Analysis of Variance↗
Relationship between glucose metabolism and pancreatic cancer.
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Blood Glucose↗
Vecuronium pharmacokinetics and pharmacodynamics during hypothermic cardiopulmonary bypass in infants and children.
PURPOSE: To determine the effect of moderate and deep hypothermic cardiopulmonary bypass (CPB) on the pharmacokinetic and pharmacodynamic behaviour of vecuronium in infants and children. METHODS: We studied 12 patients undergoing surgery for congenital heart disease under narcotic-nitrous oxide anesthesia. Neuromuscular blockade was maintained constant (TI 4-10% by Datex electromyograph) by adjusting a vecuronium infusion. Plasma vecuronium concentrations (Cpss) were analysed by HPLC to describe a pseudosteady-state during each of the pre-CPB, CPB and post-CPB phases. Paired arterial blood samples were taken 20 min apart after at least 20 min of constant infusion. RESULTS: Nine cases were analysed, mean age 20 mo, mean weight 9 kg. Three patients had deep and six moderate hypothermia. In the pre-CPB phase Cpss fell into two groups (mean +/- SD: 330 +/- 42 ng x ml(-1); 127 +/- 27 ng x ml(-1); P < 0.001); similarly the clearances showed a bimodal distribution (mean +/- SD: 5.08 +/- 0.94; 11.51 +/- 0.2 ml x min(-1) x kg(-1) P < 0.001), although in different patients. During CPB this bimodal distribution disappeared. Vecuronium infusion rate (VIR) decreased by 84% and 92% from pre-CPB to CPB phase in deep and moderate hypothermia groups respectively (P < 0.05), paralleled by decreases in Cpss of 36% (P > 0.05) and 52% (P < 0.05). CONCLUSION: Changes in vecuronium requirements and plasma concentrations during CPB demonstrate that vecuronium pharmacokinetics and pharmacodynamics are both affected by hypothermic CPB in infants. The finding of bimodal distributions for plasma vecuronium and vecuronium clearance highlights the need for individual monitoring of neuromuscular blockade in this age group.
Anesthesia↗
Is paediatric day case tonsillectomy desirable? The parents' perspective.
Tonsillectomy is the most commonly performed otolaryngological procedure in most units. There is considerable financial pressure to perform paediatric tonsillectomy as a day case. Responding to concern that day case tonsillectomy might not be welcomed by parents or felt to be in the best interests of the patients, we carried out an audit of paediatric tonsillectomy, by means of a questionnaire for parents and nursing staff to complete while 32 consecutive patients underwent tonsillectomy as inpatients. Although eight parents (25%) felt that day surgery should be an option, none of those surveyed felt that on this occasion their child was well enough to be discharged home six hours postoperatively. Furthermore, no child in the audit fulfilled all the essential discharge criteria at six hours. In this area, at least, it appears parents do not uniformly welcome paediatric day case tonsillectomy.
Ambulatory Surgical Procedures↗
Anterior uveitis associated with latanoprost.
PURPOSE: To report the association of anterior uveitis with the use of latanoprost. METHODS: We studied four patients with complicated open-angle glaucoma who had anterior uveitis associated with the use of latanoprost. The uveitis was unilateral and occurred only in the eye receiving latanoprost in three patients. In one patient, latanoprost was used in both eyes, and the uveitis was bilateral. Four of five eyes had a history of prior inflammation and/or prior incisional surgery. All patients were rechallenged with the drug. RESULTS: The uveitis improved after cessation of latanoprost with or without topical corticosteroids. It recurred after rechallenging with latanoprost in all eyes. CONCLUSION: There is a possible association between latanoprost and anterior uveitis. Topical prostaglandin analogs may be relatively contraindicated in patients with a history of uveitis or prior ocular surgery. This association may also be possible in eyes that have not had previous uveitis or incisional surgery.
Administration, Topical↗
Eicosanoids in bovine retinal microcirculation.
The vasoactive effects of the arachidonic acid-derived cyclooxygenase product, prostaglandin F2 alpha and PGH2 analogue U46619, on ex vivo perfused (25 microliters/min) bovine retinal microcirculation were assessed. First, we determined the ability of the cultured bovine retinal microvascular endothelial cells to synthesize eicosanoids from 14C-arachidonic acid. Bovine retinal microvascular endothelial cell cultures synthesized detectable amounts of PGE2, PGF2 alpha, PGI2, and PGH2 analogue; PGI2 product being slightly greater. The central retinal arteriole was cannulated and microcirculation continuously perfused with PSS with constant flow. Vasoactive compounds were applied in ten-fold concentration increments to PSS in the muscle chamber containing retinal preparation. The diameters of retinal microarterioles were measured using a closed-circuit video camera system. In ex vivo bovine retinal microvascular model studies, PGF2 alpha and PGH2 analogue U46619, caused dose-dependent vasoconstriction of all vessels, and these responses were attenuated by specific TP (TXA2) receptor antagonist, SQ 29,548, at 10(-6) M.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
Ventilatory parameters in children during propofol anaesthesia: a comparison with halothane.
PURPOSE: The purpose of this study was to compare the effects of propofol on ventilation with those of halothane. METHODS: Respiration was studied in 20 spontaneously breathing children undergoing elective dental restoration randomized to receive either propofol (Group P) or halothane (Group H) anaesthesia. Data were recorded at different inspired concentrations of halothane (F1H) or propofol (RivP) during a washout of the anaesthetic agent. The F1H 2%, 1% and 0% corresponded to an end-tidal halothane concentration of 1.38 +/- 0.06%, 0.857 +/- 0.03% and 0.191 +/- 0.01% respectively. The RivP were 18, 15, 12, 9 and 0 mg.kg-1.hr-1. The inspiratory flow waveform, the CO2 waveform and the occluded inspiratory pressure waveform were recorded. The flow waveform was analyzed for minute ventilation (Vi), and tidal volume (VT), parameters of breath Timing [Total time (Ttot), Inspiratory time (Ti)] and parameters of breath Amplitude [mean inspiratory flow (VT/Ti)]. The slope of the initial 100 msec (dP/dt0.1) of an occluded inspiration, together with the occluded inspiratory time (Tiocc) and the ratio of the occluded to unoccluded inspiratory time (Tiocc/Ti) were obtained. RESULTS: There were intergroup differences in the preemergence values of Ttot, dP/dt0.1 and Tiocc/Ti. In group P the Vi, VT and Ttot increased and PETCO2 decreased during a washout of propofol. The values of dP/dt0.1 in Group P at all RivP were half the values of those in Group H. The ratio Tiocc/Ti did not change in Group P and increased in Group H during a washout of halothane. CONCLUSION: Propofol anaesthesia was associated with a decrease in Vi whereas during halothane anaesthesia, Vi did not change. Ventilation in Group P differed from Group H in parameters of both breath Drive and Timing.
Anesthesia↗
Body heat transfer during hip surgery using active core warming.
The purpose of this study was to evaluate the effect of core warming on heat redistribution from the core to the periphery as manifested by changes in core, mean skin temperature and mean body heat, investigated in a group of 30 patients undergoing total hip replacement. The control group (n = 10) had no active warming. Core warming was achieved in the humidifier group (n = 10) by using humidified and warmed gases at 40 degrees C, whilst in the oesophageal group (n = 10), an oesophageal heat exchanger was used to achieve active warming. Operating room temperature and relative humidity was standardised. Aural canal and skin temperatures (15 sites) were measured before induction of anaesthesia, at the end of surgery and one hour of recovery after anaesthesia. Mean skin temperatures were calculated for a weighted four and unweighted 15 points, and mean body heat were calculated to quantify the distribution of body heat. Core temperature decreased in the control and the oesophageal groups, but not in the humidifier group at the end of surgery; by mean values +/- SD of 1.9 degrees C +/- 0.6, 1.2 degrees C +/- 0.6 and 0.4 degree C +/- 0.2 degree C, respectively (P < 0.01). Mean skin temperature (MST15) decreased in the control group by 1.0 degree C +/- 1.0, but not in the actively warmed groups where the mean increased by 0.1 degree C +/- 1.4 and 0.2 degree C +/- 0.2 in the oesophageal and humidifier groups, respectively (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Post-surgery epidural blockade with local anaesthetics attenuates the catecholamine and thermogenic response to perioperative hypothermia.
Core (aural canal) and mean skin (15 sites) temperatures, plasma adrenaline, noradrenaline and metabolites, and gaseous exchange were measured before, during and for 4 h after surgery in sixteen patients scheduled for elective colorectal surgery. All patients received general anaesthesia and no measures were taken to prevent the perioperative loss of body heat. At time of abdominal wall closure, when the core temperature was below 35.0 degrees C, the patients were randomly allocated to receive either 20-30 mg of papaveretum i.v. (papaveretum group, n = 8) or 15 ml of bupivacaine 0.75% via thoracic (T9) epidural route to obtain a T4-S5 sensory blockade (epidural group, n = 8). Continuous infusion of either i.v. papaveretum or epidural 0.25% bupivacaine was continued after surgery. During the recovery period of four hours the rate of increase in core and mean skin temperatures was significantly slower in the epidural group compared with the papaveretum group (P < 0.01). Plasma catecholamine concentrations remained elevated after surgery in the papaveretum group, whilst they decreased significantly once epidural blockade was established (P < 0.001). There was a lower trend, however not significant, in the rise of postoperative oxygen consumption and plasma glucose concentration in the epidural group compared with the papaveretum group.
Aged↗
A novel method to assess reactivities of retinal microcirculation.
This study introduces a novel method of bovine retinal microcirculation preparation to assess reactivities of retinal microvessels in ex vivo. This preparation is perfused intraluminally through the retinal artery. Effects of vasoactive hormones on these microvessels can be studied by perfusion or topical application to muscle bath. Effects of these compounds on the retinal microvessels of 1A (180- to 200-microns diameters), 2A (50- to 60-microns diameter), and 3A (20- to 30-microns diameter) can be assessed simultaneously using video microscopy. In this study, the water-soluble compound endothelin-1, when applied topically, caused dose-dependent vasoconstriction of all microvessels but had no effect when perfused intraluminally. On the other hand, lipid-soluble prostaglandin F2 alpha (PGF alpha) caused dose-dependent vasoconstriction when administered either intra- or extraluminally. Furthermore, preconstricted retinal arterioles (by PGF alpha) were dilated in a dose-dependent manner when acetylcholine was perfused through the retinal artery. This vasodilation was attenuated by atropine or N3-monomethyl arginine, a nitric oxide synthase inhibitor. Topical potassium chloride also caused dose-dependent vasoconstriction of all retinal microvessels. Fluorescein angiography showed no breakdown of the blood-retinal barrier. Thus, in this ex vivo perfused bovine retinal microcirculation preparation, the water-soluble compounds may not cross the blood-retinal barrier to affect microcirculation while lipid soluble can affect this circulation. Additionally this study shows that endothelial-derived compounds, endothelin and nitric oxide, caused vasoconstriction and dilation, respectively.
Acetylcholine↗
Plasmacytoma of the hyoid.
A case of plasmacytoma arising from the hyoid bone is described, this is a distinctly unusual site, as the marrow-containing flat bones are more commonly affected. On a review of the literature this appears to be the first report of plasmacytoma occurring in the hyoid bone. The patient underwent a CT scan and plain radiographs. Histopathology was diagnostic.
Bone Neoplasms↗
Clinical evaluation of the oesophageal heat exchanger in the prevention of perioperative hypothermia.
We have studied the efficiency of an oesophageal warming device in the prevention of perioperative hypothermia in 22 patients undergoing total hip replacement. Aural canal and skin temperatures (15 sites) were measured before induction of anaesthesia, at the end of surgery and 1 h after recovery and mean body heat was calculated to quantify heat distribution. Core temperature decreased significantly in both groups at the end of surgery, by a mean of 1.8 degrees C in the control group and 1.3 degrees C in the oesophageal heat exchanger (treated) group (P = 0.09). In contrast, mean skin temperature at the end of surgery increased by a median value of 0.26 degrees C in the treated group and decreased by 1.02 degrees C in the control group (P = 0.03). Both groups of patients lost body heat to the same extent (P = 0.34). Thus the oesophageal heat exchanger was ineffective in preventing perioperative hypothermia in a group of patients undergoing total hip replacement.
Adult↗
Effect of adenovirus infection on adiposity in chicken.
Excessive fat accumulation has been observed in the field in chickens infected with adenovirus. In the present study this has been verified under experimental conditions. Chickens inoculated with adenovirus showed lesser weight gain but excessive adiposity compared to normal control chickens. These changes could not be explained by variation in food consumption. Chickens acquiring adenovirus naturally from the inoculated group showed similar adiposity. Serum cholesterol and triglyceride levels of inoculated and naturally infected chickens were significantly lower compared to those of the control group. Such an association between adenovirus infection and adiposity has been shown, probably, for the first time, which might help in further understanding of the complex problem of obesity.
Adenoviridae Infections↗
A comparative study between cod liver oil and liquid lard intake on intraocular pressure on rabbits.
Cod liver oil administered intramuscularly (0.2 ml/day) lowered intraocular pressure (IOP) of the rabbit from 21 mmHg to 18 +/- 0.4 mmHg (p less than 0.05 n = 8). A higher dose of cod liver oil (1 ml) further lowered intraocular pressure to 14.5 +/- 0.3 mmHg which remained at this level for up to 80 days when the rabbits were sacrificed. Intramuscular injections of liquid lard did not alter IOP in rabbits. When treatment with cod liver oil was stopped, IOP rose to baseline levels. Topical treatment with cyclooxygenase inhibitors had no effect on the IOP lowering effect of cod liver oil. Topical treatment of rabbit eyes with 1% aspirin solution twice daily (up to 28 days) and flurbiprofen t.i.d. (up to 15 days) caused no alteration in the decrease in IOP seen with intramuscular cod liver oil treatment for up to 28 and 15 days respectively.
Administration, Topical↗