Implementation of a 23-h surgery model in a tertiary care hospital: a safe and feasible model with high patient satisfaction.

BACKGROUND: The 23-h surgery model consists of elective operative care with an overnight hospital stay for patients unsuitable for day case surgery. The aim of this study was to assess the success of the 23-h surgery model. METHODS: This was a prospective follow-up study of patients undergoing surgery with the planned 23-h model in a tertiary-care university hospital during a 12-month period 2 years after the model was implemented. Patients were interviewed 2 weeks after surgery, and the hospital operative database and patient records were searched. The primary outcome was the success of the process, defined as discharge before 10.00 hours on the first morning after surgery. Secondary outcomes were 30-day readmission and reoperation rates, adverse events, and patient satisfaction with the process. RESULTS: Between May 2017 and May 2018, 993 adult patients underwent surgery with the 23-h model, of whom 937 adhered to the model as planned (success rate 94·4 per cent). Gynaecological, gastrointestinal and orthopaedic surgery were the three most common surgical specialties. The surgical process was changed to an in-hospital model for 45 patients (4·5 per cent), and 11 (1·1 per cent) were discharged on the day of surgery. The readmission rate was 1·9 per cent (19 of 993), and five patients (0·5 per cent) had a reoperation within 30 days of surgery. Fifty-nine adverse events were noted in 53 patients (5·3 per cent), most commonly infection. Patient satisfaction was a median of 6-7 (maximum 7) points for various aspects of the model. CONCLUSION: The success rate and patient satisfaction for the 23-h surgery model was high.

ANTECEDENTES: El modelo de cirugía de 23 horas consiste en un procedimiento quirúrgico electivo con estancia en el hospital durante una noche en aquellos pacientes que no son adecuados para cirugía ambulatoria. MÉTODOS: Se puso en marcha un estudio prospectivo de seguimiento de pacientes sometidos a cirugía con un modelo planificado de 23 horas en un hospital universitario de tercer nivel durante un periodo de 12 meses a los dos años de la implementación del modelo. Los pacientes fueron entrevistados a las dos semanas tras la cirugía, y se realizaron búsquedas en las bases de datos operativas y en los informes de los pacientes. El resultado primario fue el éxito del proceso definido como el alta antes de las 10 horas en la primera mañana postoperatoria. Los resultados secundarios fueron el reingreso a los 30 días y la tasa de reoperaciones, eventos adversos, y satisfacción del paciente con el proceso. RESULTADOS: Entre mayo de 2017 y mayo de 2018, 993 pacientes adultos fueron sometidos a cirugía con un modelo planificado de 23 horas, de los cuales 937 pacientes siguieron el modelo tal como se planificó (tasa de éxito 94,4%). Las tres especialidades quirúrgicas más frecuentes fueron ginecología, aparato digestivo y ortopedia. El proceso quirúrgico se cambió a un modelo de hospitalización en 45 (4,5%) pacientes, y 11 (1,1%) pacientes fueron dados de alta en el día de la cirugía. La tasa de reingreso fue del 1,9% (n = 19) y 5 pacientes (0,5%) precisaron de una reoperación en los primeros 30 días tras la cirugía. Se observaron eventos adversos en 53 pacientes (5,3%), siendo una infección el más frecuente. La satisfacción del paciente tuvo una mediana de 6-7 (de un total de 7) puntos para varios aspectos del modelo. CONCLUSIÓN: La tasa de éxito y la satisfacción del paciente del modelo de cirugía de 23 horas son elevadas.

Comprehensive real-time epidemiological data from respiratory infections in Finland between 2010 and 2014 obtained from an automated and multianalyte mariPOC® respiratory pathogen test.

Respiratory viruses cause seasonal epidemics every year. Several respiratory pathogens are circulating simultaneously and typical symptoms of different respiratory infections are alike, meaning it is challenging to identify and diagnose different respiratory pathogens based on symptoms alone. mariPOC® is an automated, multianalyte antigen test which allows the rapid detection of nine respiratory infection pathogens [influenza A and B viruses, respiratory syncytial virus (RSV), human metapneumovirus, adenovirus, parainfluenza 1-3 viruses and pneumococci] from a single nasopharyngeal swab or aspirate samples, and, in addition, can be linked to laboratory information systems. During the study period from November 2010 to June 2014, a total of 22,485 multianalyte respi tests were performed in the 14 participating laboratories in Finland and, in total, 6897 positive analyte results were recorded. Of the tested samples, 25 % were positive for one respiratory pathogen, with RSV (9.8 %) and influenza A virus (7.2 %) being the most common findings, and 0.65 % of the samples were multivirus-positive. Only small geographical variations in seasonal epidemics occurred. Our results show that the mariPOC® multianalyte respi test allows simultaneous detection of several respiratory pathogens in real time. The results are reliable and give the clinician a picture of the current epidemiological situation, thus minimising guesswork.

Weight loss after bariatric surgery normalizes brain opioid receptors in morbid obesity.

Positron emission tomography (PET) studies suggest opioidergic system dysfunction in morbid obesity, while evidence for the role of the dopaminergic system is less consistent. Whether opioid dysfunction represents a state or trait in obesity remains unresolved, but could be assessed in obese subjects undergoing weight loss. Here we measured brain µ-opioid receptor (MOR) and dopamine D2 receptor (D2R) availability in 16 morbidly obese women twice-before and 6 months after bariatric surgery-using PET with [(11)C]carfentanil and [(11)C]raclopride. Data were compared with those from 14 lean control subjects. Receptor-binding potentials (BPND) were compared between the groups and between the pre- and postoperative scans among the obese subjects. Brain MOR availability was initially lower among obese subjects, but weight loss (mean=26.1 kg, s.d.=7.6 kg) reversed this and resulted in ~23% higher MOR availability in the postoperative versus preoperative scan. Changes were observed in areas implicated in reward processing, including ventral striatum, insula, amygdala and thalamus (P's<0.005). Weight loss did not influence D2R availability in any brain region. Taken together, the endogenous opioid system plays an important role in the pathophysiology of human obesity. Because bariatric surgery and concomitant weight loss recover downregulated MOR availability, lowered MOR availability is associated with an obese phenotype and may mediate excessive energy uptake. Our results highlight that understanding the opioidergic contribution to overeating is critical for developing new treatments for obesity.

The prognostic significance of declining health-related quality of life scores at 6 months after coronary artery bypass surgery.

PURPOSE: Health-related quality of life (HRQoL) measured on the EQ-5D (European quality of life-5 dimensions)-questionnaire has been shown to improve after coronary artery bypass grafting (CABG), this study investigated whether changes in HRQoL predict later morbidity. METHODS: Included were 404 consecutive patients undergoing isolated CABG between 2008 and 2010 who filled the EQ-5D-questionnaire at baseline and 6 months postoperatively. Records were reviewed for later major adverse cardiac and cerebrovascular events (MACCE) after 6 months. Follow-up was 38.6 months (10-58). RESULTS: Patients who suffered later MACCE more often had suffered an in-hospital postoperative stroke, had a longer in-hospital stay, had lower HRQoL scores at 6 months and deteriorated on several EQ-5D-subscales. Logistic regression showed 6 months visual analogue scale scores and declining function scores to be independent predictors of later MACCE. CONCLUSION: Deteriorating function and HRQoL-scores at 6 months as compared to baseline postoperatively predict later adverse cardiovascular events after CABG.

Reversible and regionally selective downregulation of brain cannabinoid CB1 receptors in chronic daily cannabis smokers.

Chronic cannabis (marijuana, hashish) smoking can result in dependence. Rodent studies show reversible downregulation of brain cannabinoid CB(1) (cannabinoid receptor type 1) receptors after chronic exposure to cannabis. However, whether downregulation occurs in humans who chronically smoke cannabis is unknown. Here we show, using positron emission tomography imaging, reversible and regionally selective downregulation of brain cannabinoid CB(1) receptors in human subjects who chronically smoke cannabis. Downregulation correlated with years of cannabis smoking and was selective to cortical brain regions. After ∼4 weeks of continuously monitored abstinence from cannabis on a secure research unit, CB(1) receptor density returned to normal levels. This is the first direct demonstration of cortical cannabinoid CB(1) receptor downregulation as a neuroadaptation that may promote cannabis dependence in human brain.

The effect of waiting time on health and quality of life outcomes and costs of medication in hip replacement patients: a randomized clinical trial.

OBJECTIVE: To evaluate the effect of waiting time on health and quality of life outcomes and costs of medication in total hip replacement (THR) patients in a randomized clinical trial. METHODS: 395 THR patients were recruited into the study. When placed on the waiting list, patients were randomized into a short (< or =3 months) or a non-fixed waiting time (NFWT) (>3 months) group. In the final analyses 309 patients (179 women) with a mean age of 65 years were included. Health-related quality of life (HRQoL) (generic 15D), and pain and function (modified Harris Hip Score (HHS)) were calculated when placed on the waiting list, at hospital admission, and at 3 and 12 months postoperatively. The costs of disease-specific medication were calculated at the same measurement points. All analyses were performed using the intention-to-treat (ITT) principal. RESULTS: Of the recruited patients, 309 (78%) completed the follow-up (short group 140 and non-fixed group 169 patients). The mean waiting time was 74 days in the short and 194 days in the NFWT groups. In the ITT analyses there were no statistically significant differences between the groups in the weekly use and costs of medication, HRQoL or HHS at baseline, at admission, or 3 or 12 months after surgery. The only difference was in total medication costs during the waiting time period, at EUR 83 and 171, respectively. CONCLUSIONS: The length of the waiting time did not generate different effects on the studied health and quality of life outcomes of the randomized groups. However, those in short waiting time group reached earlier better HRQoL.

Novel mechano-acoustic technique and instrument for diagnosis of cartilage degeneration.

Fibrillation of articular surface and depletion of proteoglycans are the structural changes related to early osteoarthrosis. These changes make cartilage softer and prone to further degeneration. The aim of the present study was to combine mechanical and acoustic measurements towards quantitative arthroscopic evaluation of cartilage quality. The performance of the novel ultrasound indentation instrument was tested with elastomers and bovine articular cartilage in vitro. The instrument was capable of measuring elastomer thickness (r = 1.000, p < 0.01, n = 8) and dynamic modulus (r = 0.994, p < 0.01, n = 13) reliably. Osteochondral plugs were tested before and after enzymatic degradation of cartilage proteoglycans by trypsin or chondroitinase ABC, and of cartilage collagens by collagenase. Trypsin and collagenase induced a mean decrease of -31.2 +/- 12.3% (+/- SD, p < 0.05) and -22.9 +/- 20.8% (p = 0.08) in dynamic modulus, respectively. Rate of cartilage deformation, i.e. creep rate, increased by +117.8 +/- 71.4% (p < 0.05) and +24.7 +/- 35.1% (p = 0.17) in trypsin and chondroitinase ABC treatments, respectively. Collagenase induced a greater decrease in the ultrasound reflection from the cartilage surface (-54.2 +/- 29.6%, p < 0.05) than trypsin (-17.1 +/- 13.5%, p = 0.08). In conclusion, combined quantitation of tissue modulus, viscoelasticity and ultrasound reflection from the cartilage surface provides a sensitive method to distinguish between normal and degenerated cartilage, and even to discern proteoglycan loss and collagen degradation from each other.

The N-methyl-D-aspartate antagonist memantine has no neuroprotective effect during hypothermic circulatory arrest: a study in the chronic porcine model.

BACKGROUND: Glutamate excitotoxicity has an important role in the development of brain injury after prolonged hypothermic circulatory arrest. The goal of the present study was to determine the potential efficacy of memantine, an N -methyl-D -aspartate receptor antagonist, to mitigate cerebral injury after hypothermic circulatory arrest. METHODS: Twenty pigs (23-33 kg) were randomly assigned to receive memantine (5 mg/kg) or placebo in a blinded fashion before a 75-minute period of hypothermic circulatory arrest at 20 degrees C. Hemodynamic, electroencephalographic, and metabolic monitoring were carried out. The intracerebral concentrations of glucose, lactate, glutamate, and glycerol were measured by means of enzymatic methods on a microdialysis analyzer. Daily behavioral assessment was performed until the animals died or were put to death on day 7. Histologic analysis of the brain was carried out in all animals. RESULTS: In the memantine group, 5 of 10 animals survived 7 days compared with 9 of 10 in the placebo group. The median behavioral score at day 7 was 3.5 in the memantine group and 7.5 in the placebo group (P >.2). Among the surviving animals, medians were 9.0 and 8.0 on day 7 (P >.2), respectively. The medians of recovered electroencephalographic bursts were equal in both groups. The median of total histopathologic score was 16 in the memantine group and 14 in the placebo group (P >.2). There was a negative correlation between glutamate levels and electroencephalographic burst recovery (tau = -0.377, P =.043). A positive correlation was found between the highest individual glutamate value and histopathologic score (tau = 0.336, P =.045). CONCLUSIONS: The present study demonstrates that memantine has no neuroprotective effect after hypothermic circulatory arrest in the pig. In addition, we have shown the accuracy of cerebral glutamate measurements to predict histopathologic injury after hypothermic ischemia.

Leukocyte filtration improves brain protection after a prolonged period of hypothermic circulatory arrest: A study in a chronic porcine model.

BACKGROUND: Ischemic cerebral injury follows a well-attested sequence of events, including 3 phases: depolarization, biochemical cascade, and reperfusion injury. Leukocyte infiltration and cytokine-mediated inflammatory reaction are known to play a pivotal role in the reperfusion phase. These events exacerbate the brain injury by impairing the normal microvascular perfusion and through the release of cytotoxic enzymes. The aim of the present study was to determine whether a leukocyte-depleting filter (LeukoGuard LG6, Pall Biomedical, Portsmouth, United Kingdom) could improve the cerebral outcome after hypothermic circulatory arrest. METHODS: Twenty pigs (23-30 kg) were randomly assigned to undergo cardiopulmonary bypass with or without a leukocyte-depleting filter before and after a 75-minute period of hypothermic circulatory arrest at 20 degrees C. Electroencephalographic recovery, S-100beta protein levels, and cytokine levels (interleukin 1beta, interleukin 8, and tumor necrosis factor alpha) were recorded up to the first postoperative day. Postoperatively, all animals were evaluated daily until death or until electively being put to death on day 7 by using a quantitative behavioral score. A postmortem histologic analysis of the brain was carried out on all animals. RESULTS: The rate of mortality was 2 of 10 in the leukocyte-depletion group and 5 of 10 in control animals. The risk for early death in control animals was 2.5 (95% confidence interval, 0.63-10.0) times higher than that of the leukocyte-depleted animals. The median behavioral score at day 7 was higher in the leukocyte-depletion group (8.5 vs 3.5; P =.04). The median of total histopathologic score was 8.5 in the leukocyte-depletion group and 15.5 in the control group (P =.005). CONCLUSION: A leukocyte-depleting filter improves brain protection after a prolonged period of hypothermic circulatory arrest.

Some aspects on death in the cold and concomitant frostbites.

The most important risk factors and findings of acute accidental hypothermia and concomitant local frostbites are reviewed. Both external and internal risk factors are usually present when exposure to cold is leading to death. The external factors are alcohol and psychic drugs, too light a clothing for the circumstances and wetness. Important internal factors are leanness, physical exhaustion and traumas in young persons and illnesses and degeneration of physiological heat conserving and production responses at old age. The signs caused by cold on the body are variable. In immersion hypothermia cases there are almost no changes, since the death occurs rapidly, most frequently from drowning. On the victims of dry frost first degree congelations, showing up as purple oedematic skin areas or spots, can be observed on the face and extremities. Stress ulcerations or haemorrhages in the stomach mucosa develop in ca. 70% of dry hypothermia cases. In long lasting exposures to cool temperature haemorrhagic pancreatitis, lung oedema and myxomatous skin oedema have been the characteristic signs. Frostbites developing concomitantly with fatal hypothermia show only oedema and hyperaemia, but no blisters or inflammation in the skin, which are the most conspicious vital reactions of frostbites after thawing.

Lamotrigine improves cerebral outcome after hypothermic circulatory arrest: a study in a chronic porcine model.

BACKGROUND: Glutamate excitotoxicity has an important role in the development of brain injury after prolonged hypothermic circulatory arrest. The goal of the present studies was to determine the potential efficacy of lamotrigine, an Na(+) channel blocker, to mitigate cerebral injury after hypothermic circulatory arrest. METHODS: Sixteen pigs (21-27 kg) were randomly assigned to receive lamotrigine (20 mg/kg) or placebo in a blinded fashion before a 75-minute period of hypothermic circulatory arrest (20 degrees C). Hemodynamic, electroencephalographic, and metabolic monitoring were carried out. S-100beta protein was determined up to the first postoperative morning. Daily behavioral assessment was performed until the animal died or was put to death on day 7. Histologic analysis of the brain was carried out in all animals. RESULTS: Complete behavioral recovery was seen in 5 of 8 (63%) animals after lamotrigine administration, compared with 1 of 8 (13%) in the placebo group (P =.02). Among the animals that survived for 7 days, the median behavioral score was higher in the lamotrigine group (8 vs 7, P =.02). The medians of recovered electroencephalographic bursts in the lamotrigine group were higher than those in the placebo group 4 1/2 hours after the start of rewarming (P =.01). The median S-100beta level was lower in the lamotrigine group (0.01 microg/L) than in placebo controls (0.1 microg/L) 20 hours after the start of rewarming (P =.01). The median of total histopathologic score was 5.5 in the lamotrigine group and 7.5 in the placebo group (P =.06). CONCLUSIONS: The present data suggest that lamotrigine improves neurologic outcome after a prolonged period of hypothermic circulatory arrest.

Is maintained cranial hypothermia the only factor leading to improved outcome after retrograde cerebral perfusion? An experimental study with a chronic porcine model.

BACKGROUND: Previous studies have shown that retrograde cerebral perfusion can improve neurologic outcome after prolonged hypothermic circulatory arrest. Here we have compared two temperatures of retrograde cerebral perfusion (15 degrees C and 25 degrees C) with hypothermic circulatory arrest at systemic hypothermia of 25 degrees C to clarify whether the possible benefit of retrograde cerebral perfusion may only be due to improved cooling effect. METHODS: Eighteen pigs (23-27 kg) were randomly assigned to undergo 15 degrees C retrograde cerebral perfusion at systemic hypothermia of 25 degrees C, 25 degrees C retrograde cerebral perfusion at 25 degrees C systemic hypothermia, or hypothermic circulatory arrest at 25 degrees C for 40 minutes. Flow was adjusted to maintain superior vena cava pressure at 20 mm Hg during retrograde cerebral perfusion. Hemodynamic, electrophysiologic, metabolic, and temperature monitoring were performed until 4 hours after the start of rewarming. Daily behavioral assessment was done until death or until the animals were killed on day 7. Histopathologic analysis of the brain was carried out on all animals. RESULTS: Epidural temperatures were lower in the 15 degrees C retrograde cerebral perfusion group during the intervention (P <.05). In the 15 degrees C retrograde cerebral perfusion group, 4 (67%) of 6 animals survived for 7 days compared with 3 (50%) of 6 in both the 25 degrees C retrograde cerebral perfusion and hypothermic circulatory arrest groups. The median total histopathologic score was 5 in the 15 degrees C retrograde cerebral perfusion group and 7 in the 25 degrees C retrograde cerebral perfusion group (P =.04). CONCLUSIONS: These findings suggest that enhanced cranial hypothermia is the major beneficial factor of retrograde cerebral perfusion when careful attention is paid to its implementation.

Adenosine A1/A2a receptors mediate suppression of mismatch negativity by ethanol in humans.

Acute alcohol challenge suppresses the mismatch negativity (MMN) component of the auditory event-related potential (ERP), however, the transmitter systems underlying MMN generation/mediating this effect have remained vague. To test adenosinergic contribution, 12 healthy social drinkers participated in four sessions, ingesting: (1) placebo pill and placebo beverage; (2) caffeine (100 mg) and placebo beverage; (3) placebo pill and alcohol (0.55 g/kg in 10% (v/v) solution); or (4) both caffeine and alcohol. ERP measured during a dichotic-listening task disclosed increased MMN and P3b peak latencies, and diminished amplitude of processing negativity (PN) with alcohol, however, only the increase in MMN peak latency was significantly antagonized by caffeine. The results suggest that A1 and A2a receptors play a role in the generation of, and mediate partly the suppressant effect of ethanol on, the MMN.

Serum S-100beta protein predicts brain injury after hypothermic circulatory arrest in pigs.

OBJECTIVE: Serum S-100beta protein is suggested to be a neurobiochemical marker of brain injury after cardiac and aortic arch surgery. The aim of the present study was to investigate the predictive value of S-100beta protein with respect to histopathological analysis of the brain after a prolonged period of hypothermic circulatory arrest (HCA). METHODS: Eighteen pigs (21 to 31 kg) underwent a 75 min period of HCA at 20 degrees C. Serum concentrations of S-100beta were assayed in mixed venous blood before and 2, 4, 7 and 20 h after HCA. A semiquantitative post-mortem histopathological analysis scoring all main regions of the brain was carried out in every animal. RESULTS: All animals were stable during and after cardiopulmonary bypass (CPB) and survived at least to the first postoperative day. Ten of the 18 animals survived 7 days after surgery and were electively sacrificed. Animals with severe histopathological injury showed higher serum S-100beta protein levels at every time point after HCA. The strongest correlation between the total histopathologic score and serum S-100beta levels was found at 7 h after HCA (tau = 0.422 and p = 0.023). CONCLUSION: Serum S-100beta protein levels correlate with histopathological injury after a prolonged period of HCA in pigs. This finding supports the results of previous studies suggesting the potential accuracy of S-100beta in the prediction of brain injury after cardiac surgery.

Cold retrograde cerebral perfusion improves cerebral protection during moderate hypothermic circulatory arrest: A long-term study in a porcine model.

BACKGROUND: Deep hypothermic circulatory arrest is an effective method of cerebral protection, but it is associated with long cardiopulmonary bypass times and coagulation disturbances. Previous studies have shown that retrograde cerebral perfusion can improve neurologic outcomes after prolonged hypothermic circulatory arrest. We tested the hypothesis that deep hypothermic retrograde cerebral perfusion could improve cerebral outcome during moderate hypothermic circulatory arrest. METHODS: Twelve pigs (23-29 kg) were randomly assigned to undergo either retrograde cerebral perfusion (15 degrees C) at 25 degrees C or hypothermic circulatory arrest with the head packed in ice at 25 degrees C for 45 minutes. Flow was adjusted to maintain superior vena cava pressure at 20 mm Hg throughout retrograde cerebral perfusion. Hemodynamic, electrophysiologic, metabolic, and temperature monitoring were carried out until 4 hours after the start of rewarming. Daily behavioral assessment was performed until elective death on day 7. A postmortem histologic analysis of the brain was carried out on all animals. RESULTS: In the retrograde cerebral perfusion group, 5 (83%) of 6 animals survived 7 days compared with 2 (33%) of 6 in the hypothermic circulatory arrest group. Complete behavioral recovery was seen in 4 (67%) animals after retrograde cerebral perfusion but only in 1 (17%) animal after hypothermic circulatory arrest. Postoperative levels of serum lactate were higher, and blood pH was lower in the hypothermic circulatory arrest group. There were no significant hemodynamic differences between the study groups. CONCLUSIONS: Cold hypothermic retrograde cerebral perfusion during moderate hypothermic circulatory arrest seems to improve neurologic outcome compared with moderate hypothermic circulatory arrest with the head packed in ice.

Acute phase response in dairy cows with experimentally induced Escherichia coli mastitis.

Six Finnish Ayrshire cows were challenged intramammarily with 1500 CFU of Escherichia coli (E. coli) into single udder quarters, and the challenge was repeated into contralateral quarters 3 weeks later. All cows received flunixine meglumine once, and 3 of them were also treated with enrofloxacin. At the 2nd challenge, treatments were changed vice versa. The development of mastitis was followed by monitoring of systemic and local clinical signs, and with serial milk and serum samples. Intramammary challenge with E. coli produced clinical mastitis in all cows, the severity of the disease varying greatly between the animals. No significant changes between the 2 treatment regimens or sequent challenges were found for any of the clinical parameters. The response of each cow followed the same pattern after both challenges; three of the cows became mildly and the other 3 either moderately or severely affected. Two severely affected cows had to be euthanized because of severe mastitis. Serum haptoglobin and amyloid-A concentrations peaked 2-3 days after bacterial challenge. Serum haptoglobin did not correlate with the severity of the disease. Serum amyloid-A rose gradually in the severely affected cows, and significant differences were found between severely versus moderately or mildly affected cows at day 4. Serum tumor necrosis factor alpha concentrations increased only in the severely affected cows. Serum cortisol response was prolonged in the severely diseased animals, and was significantly lower after the second challenge. Serum nitrite/nitrate concentration increased in the severely affected cows. This indicated excess nitric oxide production during acute E. coli mastitis. Strongly decreased milk production, and high bacterial growth in the infected quarters were best predictors for the outcome from acute E. coli mastitis.

Transdermal iontophoresis: modulation of electroosmosis by polypeptide.

The objective of this research was to further evaluate the relative importance of electrorepulsion and electroosmosis to the mechanism of enhanced transport across the skin during iontophoresis. Specifically, the impact of iontophoresing into the skin positively and negatively charged polypeptides (poly-L-lysines and poly-L-glutamic acids, respectively) on the membrane's permselectivity and hence on the quantity and direction of electroosmotic flow, was examined. Experiments were performed in vitro at pH 7.4 using conventional methodology; electroosmosis during the iontophoresis of the polypeptides into and across the skin was tracked in the usual way via the movement of the polar, uncharged, non-metabolizable marker, D-mannitol. Electrotransport of the cationic polypeptides attenuated electroosmotic flow in the normal anode-to-cathode direction; the degree of inhibition was correlated both with the initial concentration of poly-L-lysine in the anodal chamber and with the molecular weight of the polypeptide employed (from 1 to 25 kilodaltons). Iontophoresis of the anionic poly-L-glutamic acids from the cathode provoked a slight increase in electroosmotic flow in the 'reverse' direction (i.e. from the receptor phase beneath the skin towards the cathode chamber located on the epidermal side of the membrane); this effect, however, was much less dramatic than that produced in the opposite sense by the cationic polypeptides. The results suggest that driving large positively-charged polypeptide molecules into the skin leads to neutralization of the membrane's negativity, a subsequent loss of permselectivity and a concomitant attenuation of electroosmosis in the conventional anode-to-cathode direction. Presumably, the relatively poor iontophoretic permeability of these species (which becomes more and more evident with increasing molecular weight) results in a sufficiently important association of the polypeptide with the skin during the period of current passage. Much less significant effects are realized by the cathodal iontophoresis of poly-anions due to the difficulty of 'pushing' negative ions into an already negatively-charged membrane.

Acute-phase response in dairy cows with surgically-treated abdominal disorders.

Ninety-seven dairy cows suffering from traumatic reticuloperitonitis, abomasal displacement, and other gastrointestinal disorders or dystocia were referred for abdominal surgery. Plasma protein concentrations, including plasma fibrinogen and haptoglobin, and conventional haematological variables were determined both pre- and postoperatively. The examined variables were not of value in predicting the outcome of the abdominal disorders in general, but fibrinogen concentrations may be helpful in postoperative monitoring of infectious complications, such as peritonitis. Fifty-five per cent of the cows had increased haptoglobin concentrations preoperatively and abdominal surgery led to an additional haptoglobin increase for a further 2-3 days. It is recommended that pre- and postoperative haptoglobin values should be compared when monitoring infectious complications. Non-parametric receiver operating characteristics (ROC) analysis suggested that plasma haptoglobin concentration was the most accurate parameter for differentiating traumatic reticuloperitonitis from other gastrointestinal disorders, but plasma fibrinogen and globulin concentrations were also of value in this respect.

Influence of transient overdistension on bladder wall morphology and enzyme histochemistry.

Bladder overdistension has been found to cause transitional morphological changes in innervation which correlate with changes in micturition and bladder contractility. We investigated the influence of overdistension on bladder wall morphology using histological and enzyme histochemical methods. Overdistension was induced in female rats for 3 h by forced diuresis and balloon obstruction of the bladder neck. Oedema was seen beneath the mucosa at 12 h, with hyperemia and haemorrhages. The urothelium was mostly intact, although enzymes leaked out of the epithelial cells. The changes were increased at 24 h. The urothelium also showed some disruptions and degenerative vacuolization. The oedema reached its maximum at 48 h, and large numbers of inflammatory cells were also seen. The urothelium was disruptured in many places and vacuolated, but the subendothelial capillaries remained normal. Damage to some muscle cells was seen. After 7 days the oedema had disappeared and the urothelium was continuous. Enlarged nuclei were seen as white spots in the epithelial cells. Numbers of inflammatory cells were similar to those in the controls. Overdistension causes damage primarily to the bladder urothelium, and to a lesser extent to the muscular layer. Urothelium integrity is destroyed for several days, which makes it possible for various substances to penetrate the bladder wall and allows for bacterial adherence. The damage however is, almost completely healed within one week.