Effects of a six-week intraduodenal supplementation with quercetin on liver lipid metabolism and oxidative stress in peripartal dairy cows

The purpose of this study was to evaluate possible effects of quercetin (Q) on liver lipid metabolism and antioxidative status in periparturient dairy cows. The periparturient period is associated with enormous metabolic changes for dairy cows. Energy needs for incipient lactation are too high to be balanced by feed intake, leading to negative energy balance and body fat mobilization. It has been estimated that this leads to the development of fatty liver in about 50% of cows, which are at high risk for disease. Furthermore, the antioxidative status of these cows may be impaired. Quercetin is a plant flavonoid having hepatoprotective and antioxidative potential and the ability to reduce liver lipid accumulation in monogastric animals. Little information is available in regard to these effects in ruminants. To prevent microbial Q degradation in the rumen, Q was administered via a duodenal fistula to improve systemic availability. Five cows of the Q-treated group received, daily, 100 mg of quercetin dehydrate/kg BW in a 0.9% sodium chloride solution from d -20 until d 20 relative to calving, whereas 5 control (CTR) cows received only a sodium chloride solution. Blood samples were taken weekly and liver biopsies were performed in wk -4, -2, and 3 relative to calving. Cows treated with Q showed a tendency ( = 0.082) for lower liver fat content compared with CTR cows. Liver glycogen, glutathione concentrations, and relative mRNA abundance of genes related to hepatic lipid metabolism and antioxidative status as well as parameters of antioxidative status in plasma were not affected ( > 0.1) by Q supplementation. In conclusion, liver fat content in dairy cows tended to be reduced by Q supplementation, but potential underlying mechanisms remain unclear because analyzed parameters related to hepatic lipid metabolism and antioxidative defense were not altered by Q supplementation.

[Modulation of the intestinal microbiota by nutritional interventions]

Humans live in symbiosis with billions of commensal bacteria. The so-called microbiota live on different biological interfaces such as the skin, the urogenital tract and the gastrointestinal tract. Commensal bacteria replace potentially pathogenic microbes, synthesize vitamins and ferment dietary fibre. An imbalance in the bacterial composition of the intestinal microbiota has been associated with various diseases including gut-associated disorders such as inflammatory bowel diseases, colorectal cancer and nonalcoholic fatty liver disease. Furthermore, a shift in the microbiota composition appears to be of pathophysiological relevance which renders the specific modulation of the intestinal microbiota a promising approach in the treatment of the above mentioned diseases. Our intestinal microbiota composition is mainly modulated by dietary macro- and micronutrients but also by secondary plant compounds and synthetic food additives such as emulsifiers and artificial sweeteners. Nutritional interventions with the purpose to modulate the intestinal microbiota show only limited therapeutic potential in the treatment of gut-associated disorders, which may be due to individual differences in the intestinal microbiota composition and a lack of specificity. A combination of newly established technical analytic approaches involving a machine-learning algorithm may bridge the currently existing limitations by providing a personalized, highly-specific and consequently therapeutically effective microbiota modulation.

3,3'-Diindolylmethane but not indole-3-carbinol activates Nrf2 and induces Nrf2 target gene expression in cultured murine fibroblasts

There is increasing interest in the gene-regulatory activity of Brassica vegetable derived phytochemicals such as 3,3'-diindolylmethane (DIM) and indole-3-carbinol (I3C). DIM is formed under acidic conditions by dimerization of I3C. This study compared the Nrf2 activating potential of DIM and I3C in murine fibroblasts (NIH3T3). In contrast to its precursor I3C, DIM induces the transactivation of Nrf2. Furthermore, Nrf2 targets such as HO-1, γGCS and NQO1 were increased on the mRNA and protein levels following DIM treatment. DIM was less potent than sulforaphane (used as positive control) in inducing Nrf2-dependent gene expression. The present data suggest that the dimerization of I3C to DIM increases its Nrf2 inducing activity.

Ochratoxin A impairs Nrf2-dependent gene expression in porcine kidney tubulus cells

The mycotoxin, ochratoxin A (OTA), which is produced by Aspergillus and Penicillium subspecies, is frequently present in feedstuffs. Ochratoxin A exhibits a wide range of toxic activities including nephrotoxicity. However, the underlying molecular mechanisms of OTA-induced cellular nephrotoxicity have yet not been fully elucidated. Nrf2 is a basic leucine zipper transcriptional activator essential for the coordinated transcriptional induction of antioxidant and xenobiotic metabolizing enzymes in the kidney. Therefore, in the present study, the effects of OTA on the nuclear translocation and transactivation of the transcription factor Nrf2 as well as mRNA levels of Nrf2 target genes including glutathione-S-transferase and gamma-glutamylcysteinyl synthetase have been studied in cultured porcine kidney tubulus cells (LLC-PK1). Nrf2 was induced by sulforaphane, a well-known activator of this transcription factor. Ochratoxin A significantly decreased gamma-glutamylcysteinyl synthetase and glutathione-S-transferase mRNA levels in LLC-PK1 cells. Decreased mRNA levels of gamma-glutamylcysteinyl synthetase and glutathione-S-transferase were accompanied by a lowered nuclear translocation and transactivation of Nrf2. Furthermore, OTA also lowered Nrf2 mRNA levels. Current data indicate that OTA nephrotoxicity may be, at least partly, mediated by an Nrf2-dependent signal transduction pathway.

Dexamethasone impairs hypoxia-inducible factor-1 function

Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric transcription-factor composed of alpha- and beta-subunits. HIF-1 is not only necessary for the cellular adaptation to hypoxia, but it is also involved in inflammatory processes and wound healing. Glucocorticoids (GC) are therapeutically used to suppress inflammatory responses. Herein, we investigated whether GC modulate HIF-1 function using GC receptor (GR) possessing (HepG2) and GR deficient (Hep3B) human hepatoma cell cultures as model systems. Dexamethasone (DEX) treatment increased HIF-1alpha levels in the cytosol of HepG2 cells, while nuclear HIF-1alpha levels and HIF-1 DNA-binding was reduced. In addition, DEX dose-dependently lowered the hypoxia-induced luciferase activity in a reporter gene system. DEX suppressed the hypoxic stimulation of the expression of the HIF-1 target gene VEGF (vascular endothelial growth factor) in HepG2 cultures. DEX did not reduce hypoxically induced luciferase activity in HRB5 cells, a Hep3B derivative lacking GR. Transient expression of the GR in HRB5 cells restored the susceptibility to DEX. Our study discloses the inhibitory action of GC on HIF-1 dependent gene expression, which may be important with respect to the impaired wound healing in DEX-treated patients.

Effects of diazepam and flumazenil on minimum alveolar concentrations for dogs anesthetized with isoflurane or a combination of isoflurane and fentanyl

OBJECTIVE

To determine the effect of a constant-rate infusion of fentanyl on minimum alveolar concentration (MAC) of isoflurane and to determine the interaction between fentanyl and a benzodiazepine agonist (diazepam) and antagonist (flumazenil) in isoflurane-anesthetized dogs.

ANIMALS

8 mixed-breed adult dogs.

PROCEDURE

Dogs were anesthetized with isoflurane 3 times during a 6-week period. After a 30-minute equilibration period, each MAC determination was performed in triplicate, using standard techniques. Fentanyl was administered as a bolus (10 microg/kg of body weight, IV) that was followed by a constant infusion (0.3 microg/kg per min, IV) throughout the remainder of the experiment. After determining isoflurane-fentanyl MAC in triplicate, each dog received saline (0.9% NaCl) solution, diazepam, or flumazenil. After 30 minutes, MAC was determined again.

RESULTS

Fentanyl significantly decreased isoflurane MAC (corrected to a barometric pressure of 760 mm Hg) from 1.80+/-0.21 to 0.85+/-0.14%, a reduction of 53%. Isoflurane-fentanyl-diazepam MAC (0.48+/-0.29%) was significantly less than isoflurane-fentanyl-saline MAC (0.79+/-0.21%). Percentage reduction in isoflurane MAC was significantly greater for fentanyl-diazepam (74%), compared with fentanyl-saline (54%) or fentanyl-flumazenil (61%). Mean fentanyl concentrations for the entire experiment were increased over time and were higher in the diazepam group than the saline or flumazenil groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Fentanyl markedly decreased isoflurane MAC in dogs. Diazepam, but not flumazenil, further decreased isoflurane-fentanyl MAC. Our results indicate that diazepam enhances, whereas flumazenil does not affect, opioid-induced CNS depression and, possibly, analgesia in dogs.

Changes in anesthetic sensitivity and glutamate receptors in the aging canine brain

This study investigated whether the aging process in dogs is associated with an increased sensitivity to inhalation anesthesia and whether age-related changes in glutamate receptors are related to the increased sensitivity. The mean minimum alveolar concentration (MAC) of isoflurane was 1.82 +/- .08% for 2-3 year olds and 1.45 +/- .06% for 11 years olds, indicating that there was an increased potency of isoflurane in the older dogs as compared to the young. These older animals also showed a significant decrease in binding of [3H]glutamate and [3H]dizocilpine ([3H]MK801) to N-methyl-D-aspartate (NMDA) receptors in multiple cortical and hippocampal regions. The density of binding to NMDA receptors in the cortex, using a single concentration of ligand, correlated significantly with individual MAC values. These results demonstrate that dogs experience an increase in anesthetic potency with increased age, similar to humans, and that age-related changes in the NMDA receptor may represent one mechanism underlying this increased sensitivity to anesthesia.

Neurodevelopmental outcome in ECMO vs near-miss ECMO patients at 5 years of age

The objective of this study was to compare the outcome of children at 5 years of age who were treated with extracorporeal membrane oxygenation (ECMO) and those who were critically ill but did not meet ECMO criteria, identified as near-miss ECMO. In one of the longest studies of its kind, we compared the neurodevelopmental outcome of 76 5-year-old ECMO-treated children with 20 5-year-old near-miss ECMO patients with similar primary diagnoses. The two groups were compared for demographic data, level of ventilatory support, and degree of hyperventilation. The comprehensive assessment protocol included an assessment of intelligence (IQ), attainment of preacademic and early academic skills, and parents' report of adaptive behavior. Both groups had similar demographic data and primary diagnosis. The near-miss ECMO patients required increased ventilatory support but not significantly more than the ECMO patients. The cognitive outcome was similar in both groups with mean estimated Full-Scale IQ in the normal range for near-miss and ECMO groups (89 and 97, respectively). Rates of severe mental handicap (FSIQ < 70) (near-miss = 11%, ECMO = 12%) and risk for school failure (near-miss = 38%, ECMO = 37%) were also similar. More parents of near-miss ECMO patients reported immature adaptive skills than did parents of ECMO patients, although the numbers were small in each group. Rates of parent-reported child behavior problems were similar in both groups. ECMO and near-miss ECMO patients have similar cognitive and adaptive outcomes at 5 years of age. A significant number in each group are at risk of school failure and should be closely followed up.

Cardiopulmonary measurements in dogs undergoing gastropexy without gastrectomy for correction of gastric dilatation-volvulus

OBJECTIVE

To measure cardiopulmonary variables, including cardiac index, in dogs with naturally acquired gastric dilatation-volvulus (GDV).

DESIGN

Prospective clinical study.

ANIMALS

6 dogs with GDV.

PROCEDURE

In addition to typical medical and surgical management of GDV, the dorsal metatarsal and pulmonary arteries and right atrium of the dogs were catheterized to obtain cardiopulmonary measurements before and during anesthesia and surgery.

RESULTS

All dogs underwent gastropexy but none required gastrectomy. Mean cardiac index and mean arterial blood pressure for this small population of dogs with GDV were not significantly different from those reported for clinically normal awake or anesthetized dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Dogs with naturally acquired GDV without gastric necrosis may not have the classic characteristics, including decreased cardiac index and hypotension, of hypovolemic circulatory shock.

Determination of the minimum alveolar concentration of isoflurane in llamas

OBJECTIVE

To determine the minimum alveolar concentration (MAC) of isoflurane (ISO) in llamas.

STUDY DESIGN

Prospective study.

ANIMALS

Eight adult neutered male llamas (9 +/- 1 years [x +/- SD], 177 +/- 29 kg).

METHODS

Anesthesia was induced and maintained in otherwise unmedicated llamas with a mixture of ISO in oxygen administered through a standard small-animal, semi-closed circle system using an out-of-circle, agent-specific vaporizer. The time from mask placement to intubation was recorded. Inspired and end-tidal (ET) ISO was sampled continuously. At each anesthetic concentration, a constant ET ISO was maintained for at least 20 minutes before application of a noxious electrical stimulus (50 volts, 5 Hz, 10 ms for up to 1 minute). A positive or negative response to the stimulus was recorded, and ET ISO then increased (if positive response) or decreased (if negative response) by 10% to 20%. Individual MAC was the average of multiple determinations. Body temperature was maintained at 37 +/- 1 degrees C. Selected cardiopulmonary variables (heart rate [HR], respiratory rate [RR], arterial blood pressure [ABP]) and ET ISO were recorded at hourly intervals from first ISO. Arterial blood was collected for pH, PCO2, PO2 analysis and measurement of packed cell volume (PCV) and total protein (TP) at 2 hour intervals. Following MAC determination, the anesthetic was discontinued and llamas were allowed to recover. Duration and quality of recovery were noted.

RESULTS

The time from start of induction by mask to completion of intubation took 19.1 +/- 4.8 minutes. The MAC of ISO corrected to one atmosphere at sea level (barometric pressure 760 mm Hg) in these llamas was 1.05 +/- 0.17%. Mean ABP increased from 70 +/- 26 mm Hg at the end of the first hour of anesthesia to 102 +/- 7 mm Hg measured at the end of the sixth hour of anesthesia. ET ISO decreased from 2.06 +/- 0.10% to 1.27 +/- 0.07% over the same time period, but MAC did not change with time. The duration from first ISO to discontinuation of ISO averaged 6.19 +/- 0.9 hours. Animals were able to support their heads in a sternal posture at 23 +/- 10 minutes, and stood 62 +/- 26 minutes following discontinuation of the anesthetic.

CONCLUSION

The MAC for ISO is similar to, but slightly lower than, values reported for other species.

CLINICAL RELEVANCE

Knowledge of MAC may facilitate appropriate clinical use and provide the basis for future investigation of ISO in llamas.

Attitudes of veterinary medical students, house officers, clinical faculty, and staff toward pain management in animals

OBJECTIVE

To determine whether animal factors and level of professional veterinary medical training were associated with attitudes toward pain management in animals.

DESIGN

Exploratory, descriptive survey.

SAMPLE POPULATION

Students in the College of Veterinary Medicine and Biomedical Sciences professional veterinary medical curriculum (approx 540) and clinical faculty (approx 50), house officers (approx 25), and support staff (approx 100) in the Colorado State University Veterinary Teaching Hospital.

PROCEDURE

A descriptive survey including demographic, descriptive, and case-based questions was distributed to participants. Participation was voluntary and survey results were anonymous.

RESULTS

357 of 720 surveys were completed and returned (31 by faculty, 29 by staff, 18 by house officers, and 279 by students). There was a high degree of concordance among survey participants regarding the overall importance of treating pain in animals. The extent to which pain should be alleviated and animal factors, such as breed, behavior, and clinical circumstances, accounted for much of the discordance among survey groups. Fourth-year veterinary students indicated that they were occasionally less likely to treat animals for pain than were second- or third-year veterinary students.

CLINICAL IMPLICATIONS

The diversity of opinions regarding the necessity or desirability of treating pain in animals, the apparent decrease in the likelihood of senior veterinary students to treat animals for pain under certain circumstances, and evidence of knowledge deficits regarding analgesic treatments among all groups contribute to the likelihood that pain in animals will neither be consistently recognized nor appropriately treated.

Complications and mortality associated with anesthesia in dogs and cats

The complications and mortality associated with anesthesia of dogs and cats in a university teaching hospital were determined. During one year, 2,556 dogs and 683 cats were anesthetized by the anesthesia service. Hypotension occurred in 179 (7%) dogs and 58 (8.5%) cats. Cardiac dysrhythmias occurred in 64 (2.5%) dogs and 12 (1.8%) cats. Transfusions were required in 31 (1.2%) dogs. Hypercapnea occurred in 33 (1.3%) dogs and one (less than 1%) cat. Hypoxemia occurred in 14 (0.5%) dogs. Anesthetic complications, as defined, occurred in 12.0% of dogs and 10.5% of cats, while deaths associated with the perianesthetic period occurred in 0.43% of dogs and 0.43% of cats.

The effects of hyperoxia on the biosynthesis of cyclooxygenase products and haemodynamic response to nitric oxide synthase inhibition with L-NAME in endotoxaemic pigs

The interaction between constitutive nitric oxide and oxygen may depend on the degree of tissue oxygenation and may play a critical role in the pathophysiological response to endotoxaemia. We investigated if hyperoxia (100% O2) attenuated the systemic and pulmonary vasoconstriction and increased biosynthesis of thromboxane B2 (TXB2) and 6-keto-prostaglandin (PG) F1alpha induced by inhibition of nitric oxide synthase with NG-nitro-L-arginine-methyl-ester (L-NAME) in a porcine model of endotoxaemia. Twenty-two domestic, random source pigs, weighing 15.4 +/- 2.7 kg (mean +/- standard deviation) were the subjects of this study. Pigs were anaesthetized with isoflurane in 100% O2, orotracheally intubated and ventilated to maintain normocapnia, and then instrumented for haemodynamic monitoring. Following instrumentation, pigs were maintained at an end-tidal isoflurane concentration of 2%. Pigs were randomly assigned to treatment groups: saline + 30% O2 (Control, n = 6); Escherichia coli lipopolysaccharide (5 microg/kg/h from 1 to 2 h followed by 2 microg/kg/h from 2 to 5 h) + 30% O2 (LPS, n = 4); L-NAME (0.5 mg/kg/h, from 0 to 5 h) + LPS + 100% O2 (n = 6); and L-NAME + LPS + 30% O2 (n = 6). L-NAME and endotoxin significantly (P < 0.05) increased mean arterial pressure, mean pulmonary arterial pressure, and systemic and pulmonary vascular resistance index beginning at 90 min. When results were pooled across all time periods, mean arterial pressure and mean pulmonary arterial pressure were significantly higher in the L-NAME + LPS + 30% O2 group than all other groups, reflecting pulmonary and systemic vasoconstriction. Hyperoxia attenuated the L-NAME + LPS-induced increases in TXB2 and 6-keto-PGF1alpha concentrations at 90 and 120 min and 120 min, respectively, although the differences were not statistically significant. These results support the observation that nitric oxide synthase inhibition with L-NAME has deleterious haemodynamic effects in this model of endotoxaemia. The temporal attenuation of L-NAME-induced pulmonary and systemic vasoconstriction by hyperoxia suggested that the haemodynamic effects of acute endotoxaemia were in part influenced by the relative amounts of nitric oxide and oxygen present.

Pattern of neuropsychological deficit at age five years following neonatal unilateral brain injury

The pattern of language deficit following left-hemisphere brain injury and visual/spatial deficit following right-hemisphere injury in an adult or older child is well recognized, but has been inconsistently reported following presumed neonatal brain injury. Our prospective study of 24 children at age 5 with documented neonatal unilateral brain injury lends support to the theory of hemisphere specialization at the time of birth. Twelve children who had unilateral left-hemisphere lesion were compared to 12 children with unilateral right-hemisphere lesion of similar timing and severity. Relative visual/spatial deficit following right-hemisphere lesion and receptive language deficit following left-hemisphere lesion were identified. Lateralized measures of grip strength, fine motor speed, and fine motor dexterity were not significantly different between the groups for either hand in this nonhemiparetic study sample. Only one child with a left-hemisphere lesion was left-handed, and only one child (right-lesion) had a hemiparesis.

Monitoring adequacy of ventilation by capnometry during thoracotomy in dogs

OBJECTIVE

To determine whether end-tidal partial pressure of carbon dioxide (PETCO2) was a reliable estimate of PaCO2 in dogs undergoing thoracotomy.

DESIGN

Case series.

ANIMALS

18 dogs that underwent thoracotomy.

PROCEDURE

PaCO2 and PETCO2 were measured shortly after induction of anesthesia, while dogs were breathing spontaneously; 5 minutes prior to initial skin incision, while dogs were receiving intermittent positive-pressure ventilation (IPPV); 5, 30, and 60 minutes after the thoracic cavity was opened, while dogs were receiving IPPV; and after the thoracic cavity was closed and evacuated, when dogs were again breathing spontaneously. For each period, arterial-end-tidal difference in partial pressure of carbon dioxide (PaCO2-PETCO2) was compared with PaCO2-PETCO2 for the preceding period.

RESULTS

Significant changes in PaCO2-PETCO2 from one period to the next were not detected except when values obtained 5 minutes after the thoracic cavity was opened were compared with values obtained 5 minutes before incision. The PaCO2-PETCO2 was not constant for individual dogs.

CLINICAL IMPLICATIONS

PETCO2 was not a reliable indicator of adequacy of ventilation during thoracotomy in these dogs, because it differed greatly from PaCO2, and PaCO2-PETCO2 was not consistent.

Severity of brain injury following neonatal extracorporeal membrane oxygenation and outcome at age 5 years

Neurodevelopmental evaluation in childhood provides an opportunity to study complex neurological compensation following documented neonatal brain injury, and furnishes important clinical information which may have an impact on patient care. We studied 152 term children treated with extracorporeal membrane oxygenation (ECMO) as neonates and who received routine neonatal neuroimaging and comprehensive neurodevelopmental evaluation at age 5 years. The cohort was divided into four groups based on an independent neuroimaging score: No lesion, N=88; Mild lesion, N=38; Moderate lesion, N=12; and Severe lesion, N=14. Standardized testing at age 5 included complete neuropsychological assessment, neurological evaluation, and assessment of motor function. All testing was conducted without knowledge of the neuroimaging score. The occurrence of disability by severity of neuroimaging was: No lesion=10%; Mild=13%; Moderate=33%; Severe=57%. The relative risk within the ECMO population for disability at age 5 after moderate or severe neonatal lesion was 4.3 (CI=1.0 to 17.5) and 11.7 (CI=3.3 to 41.3), respectively. The remaining non-disabled children who had moderate to severe lesions functioned within normal limits. Severity of neonatal neuroimaging was inversely associated with IQ scores, pre-academic skills, and neuromotor function. The effect size was small but the rank order was predictable. Our data identify in 5-year-old children an impact of brain lesion severity demonstrated on routine neonatal neuroimaging. The results indicate potential compensation following moderate and severe lesions, and suggest a subtle but consistent influence of even mild neonatal brain injury.

Experiences with morphine injected into the subarachnoid space in sheep

The effects of morphine (M), 0.1 mg/kg, administered into the lumbosacral subarachnoid space of sheep used for experimental stifle surgery, were investigated. In a pilot study, preservative-free morphine was administered to three sheep, morphine containing preservatives to two sheep, and saline (S) to one sheep. After recovery from anesthesia, all five sheep administered M displayed rear limb weakness. One sheep, which had received morphine containing preservatives, also licked and chewed incessantly at its flank and hindquarters during recovery. A group of 24 sheep was used to study the effects of morphine containing preservatives, injected intrathecally, on recovery from general anesthesia and hindlimb orthopedic surgery. Eight sheep received M, eight sheep received S, and eight sheep had a needle placed in the subarachnoid space without any injection (N). Times from end of anesthesia to standing varied greatly and did not differ significantly among groups (P = .73), with M sheep averaging 119 minutes; S sheep, 87 minutes; and N sheep, 83 minutes. One sheep administered M licked and chewed at its hindquarters during recovery. Another group of 24 sheep was used to study the effects of morphine containing preservatives, injected intrathecally, on postoperative lameness. Treatments were as described previously. Sheep were videotaped intermittently for 36 hours after surgery, and each sheep was scored as follows: 0 = not lame; 1 = slightly lame; and 2 = very lame. The average lameness scores, which did not differ significantly among groups (P = .21), were: M sheep, 1.07; S sheep, 0.81; and N sheep, 0.68. One sheep administered M displayed extensor spasms of the hindlimbs, and could not stand until several hours after surgery. We conclude that subarachnoid morphine at the dosage used produces no apparent benefit in sheep which have had stifle surgery, and in fact may cause detrimental side effects, such as hindlimb weakness, and pruritus or irritation of the hindquarters.

Evaluation of five common induction protocols by comparison of hemodynamic responses to surgical manipulation in halothane-anesthetized horses

OBJECTIVE

To determine whether hemodynamic responses of halothane-anesthetized horses undergoing surgical procedures depended on anesthetic induction protocols used, and to determine whether hemodynamic responses to surgical manipulation could be detected.

DESIGN

Prospective experimental study without controls.

ANIMALS

36 clinically normal horses.

PROCEDURE

Horses were allotted to 5 groups according to anesthetic induction protocol: acepromazine/guaifenesin/thiamylal, acepromazine/guaifenesin/ketamine, xylazine/guaifenesin/thiamylal, xylazine/guaifenesin/ketamine, and xylazine/diazepam/ketamine. Anesthesia was maintained with halothane. Hemodynamic measurements and blood gas values were obtained prior to the start of surgery, during surgery, and after surgery.

RESULTS

Few differences in hemodynamic measurements existed between horses in which anesthesia was induced by 5 anesthetic induction protocols, whether prior to the start of surgery or for pooled values for all 3 measurement periods. Hemodynamic responses to surgical manipulation were marked and included increased mean arterial pressure and systemic vascular resistance, and decreased cardiac index and oxygen delivery.

CLINICAL IMPLICATIONS

Choice of anesthetic induction protocol has little impact on hemodynamic function during surgery in halothane-anesthetized horses. Surgical stimulation may increase blood pressure, but does not improve cardiac index or oxygen delivery.

Neurodevelopmental status at age five years of neonates treated with extracorporeal membrane oxygenation

OBJECTIVE

To determine the neurodevelopmental status at age 5 years among children who received extracorporeal membrane oxygenation (ECMO) in the newborn period as a treatment for severe cardiorespiratory failure.

METHODS

We conducted a prospective cohort study of 103 five-year-old ECMO-treated children born between June 1984 and July 1988, and treated at our institution. Thirty-seven healthy control children were recruited locally. The assessment protocol included a complete neuropsychologic assessment, psychosocial assessment with parent questionnaires, a standard neurologic evaluation, assessment of gross motor and fine motor function, a medical history, and physical examination.

RESULTS

Major disability was present in 17 of the ECMO cohort. Eleven ECMO-treated children (11%) were mentally retarded, one of whom was profoundly impaired. Two additional children had severe learning disabilities. Cerebral palsy was diagnosed in 5 (5%) ECMO-treated children, but all cases were mild in nature and the patients were walking unaided. One child has paraplegia. The mean Full Scale, Verbal, and Performance IQs of the EMCO-treated children were within the normal range, but as a group were significantly lower than in control children (96 vs 115, p < 0.001). Children treated with ECMO had increased risk relative to the control children for academic difficulties at school age (49% VS 22%, P < 0.01) and a higher rate of behavioral problems reported by parents (42% vs 16%, p = 0.01).

CONCLUSIONS

The rate of major disability was comparable to that in other high-risk populations. The high rate of behavioral problems and increased risk of subsequent school failure among nonretarded ECMO-treated children supports the need for close follow-up of these children after hospital discharge.

Hemodynamic responses of horses to anesthesia and surgery, before and after administration of a low dose of endotoxin

Seven horses, which were part of an investigation of the effect of endotoxin administration on vascular reactivity, were anesthetized on two separate occasions for surgical excision of 4-cm sections of palmar digital artery and vein. On the first occasion, the horses were given an infusion of 1 L 0.9% NaCl solution intravenously (i.v.) just before induction of anesthesia (control); on the second occasion, the horses received an infusion of 1 L 0.9% NaCl containing Escherichia coli endotoxin, 0.1 microgram/kg (endotoxin). On both occasions, anesthesia was induced with xylazine, guaifenesin, and ketamine, and maintained with halothane in oxygen. Hemodynamic measurements were made with the horses under anesthesia immediately before beginning surgery (period 1), during skin incision (period 2), during dissection and excision of the vessels (period 3), during skin suturing (period 4), and after completion of surgery during bandaging (period 5). Hemoglobin concentration and mixed venous oxygen content were greater at all periods in horses that received endotoxin. Otherwise, there were no significant differences in hemodynamic parameters between control horses and horses administered endotoxin before beginning surgery (period 1). During surgery and bandaging, horses administered endotoxin had significantly higher heart rate (periods 3, 4, and 5), cardiac index (periods 3, 4, and 5), and oxygen delivery (periods 2, 3, 4, and 5) than did control horses, and mean arterial blood pressure (period 2) and systemic vascular resistance (periods 2, 3, 4, and 5) were less than in control horses. Compared with period 1, surgical stimulation in control horses was associated with increased mean arterial blood pressure and systemic vascular resistance (periods 2, 3, 4, and 5), but cardiac index and oxygen delivery were decreased (periods 3, 4, and 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of ephedrine on cardiovascular function and oxygen delivery in isoflurane-anesthetized dogs

The hemodynamic effects of 2 dosages of ephedrine were studied in 6 dogs anesthetized with isoflurane only (end-tidal concentration equivalent to 1.5 times minimum alveolar concentration). Following instrumentation, baseline (time 0) measurements included heart rate (HR), respiratory rate, mean arterial blood pressure (MAP), cardiac output, and blood gas tensions. Cardiac index (CI), stroke volume (SV), systemic vascular resistance (SVR), arterial oxygen content (CaO2), and oxygen delivery and consumption (DO2 and VO2, respectively) were calculated. Three dogs were given ephedrine IV at a dosage of 0.1 mg/kg of body weight, and 3 dogs were given ephedrine IV at a dosage of 0.25 mg/kg. Measurements were recorded at 5, 10, 15, 30, and 60 minutes. Each dog then received the alternate dosage of ephedrine, and measurements were again recorded at the same intervals. Effects of ephedrine varied with dosage. Neither dosage was associated with significant changes in pH, PaO2, PaCO2, VO2, or respiratory rate. Ephedrine at a dosage of 0.1 mg/kg caused transient significant increases in MAP, CI, SV, CaO2, and DO2, significant decreases in HR and SVR, and a late, slight decrease in CaO2. Ephedrine at a dosage of 0.25 mg/kg caused a greater and more prolonged increase in MAP, as well as increases in CI, SV, and SVR, and a decrease in HR. The higher dosage of ephedrine also caused a pronounced increase in hemoglobin concentration and CaO2, resulting in a 20 to 35% increase in DO2 throughout the 60-minute experiment.

Congenital diaphragmatic hernia: long-term outcome in neonates treated with extracorporeal membrane oxygenation

As more infants with congenital diaphragmatic hernia (CDH) survive with extracorporeal membrane oxygenation (ECMO), it seems prudent to detail the longterm outcome in these medically complex infants. Eighteen children with CDH-treated with postoperative ECMO were recruited for participation in this study. The mean duration of ECMO was 193 hours (range 82 to 493 hours), mean time to extubation after ECMO was 142 hours (range 34 to 312 hours), and median duration of hospitalization was 46 days (range 30 to 181 days). Of the 18 infants, 4 (22%) were discharged home requiring oxygen therapy. At follow-up the notable findings were a high incidence of gastroesophageal reflux and failure to thrive. At both 1 and 2 years of age, 50% of infants were at less than the 5th percentile for weight. At 1 and 2 years of age, 39% and 21%, respectively, were at less than the 5th percentile for weight/length ratio. A total of 16 children (89%) had clinical evidence of reflux, and 8 (44%) were discharged home on a regimen of nasogastric feedings. Reherniation occurred in 4 children (22%) and was more frequent when a patch was used. An electrocardiogram showed right ventricular hypertrophy in 6 (43%); oxygen saturation by pulse oximetry was > 95% in all children, and pulmonary artery pressure was estimated by Doppler echocardiography to be normal in 12 of 14 children examined. The neurodevelopmental outcome (Bayley Scales or Stanford-Binet scale) at 1 to 4 years of age was not dissimilar from that of other ECMO-treated children. Given the severity of illness in the neonatal period, the general health and development of children with CDH surviving after ECMO are good. Surprisingly few children have long-term respiratory complications related to pulmonary hypoplasia. Follow-up in the first few years should be aimed at aggressive nutritional intervention to prevent the growth failure that appears to be prevalent in these children.

Hemodynamic function during neurectomy in halothane-anesthetized horses with or without constant dose detomidine infusion

Nine horses were premediated with acepromazine, and anesthesia was induced with guaifenesin and thiamylal. Anesthesia was maintained in four horses with halothane in oxygen, and in five horses with halothane in oxygen plus a constant dose infusion of detomidine. Both maintenance regimens produced a MAC equivalent of 1.4 at the ambient barometric pressure. Hemodynamic and respiratory measurements were made after the horses were anesthetized, during surgical manipulations involving skin or tissues other than nerves, during manipulation and transection of digital nerves, and after surgery while the limbs were being bandaged. Heart rate was significantly higher in horses anesthetized with halothane only than in horses that also received detomidine; there were no other differences in hemodynamic function or recovery characteristics. Respiratory rate was significantly higher than baseline during soft tissue and nerve manipulations; arterial blood pressure was significantly higher after surgery began and highest during neurectomy; cardiac output and cardiac index were significantly decreased during surgery; systemic vascular resistance was significantly increased during neurectomy and bandaging and highest during neurectomy. The data suggest that the increase in blood pressure often associated with surgical stimulation is caused by increased vascular resistance and may be accompanied by a decrease in cardiac output.

Otitis media, language development, and parental verbal stimulation

Examined the impact of recurrent otitis media in the first 3 years of life on verbal abilities of 3- to 4-year-old children and the potential for parental verbal stimulation to buffer the negative effects of intermittent hearing loss. Fathers and mothers of 56 children with variable histories of otitis media participated in videotaped parent-child interactions that were used to code level of parental verbal stimulation. Measures of the children's verbal abilities were the McCarthy Verbal Scale Index and a score for the child's verbalizations with each parent. Active and engaging parental verbalizations appeared to buffer the child's developing verbal abilities from the deleterious effects of recurrent otitis. Post hoc analyses examined the implications of task structure and parent sex on parent verbal stimulation. Discussion addresses the importance of paternal involvement for the home language environment and implications for intervention.

Child illness, the parenting alliance, and parenting stress

Assessed relationship between children's minor illnesses during the first 3 years of life and parenting stress in the 4th year. Also examined whether a good parenting alliance would compensate for or moderate this relationship. Parents of 56 3- to 4-year-olds completed parenting alliance and stress questionnaires. Child morbidity, assessed from medical records, was directly related to mothers' but not fathers' feelings of stress. The parenting alliance was more strongly related to parenting stress for fathers than for mothers. However, child morbidity and parenting alliance interacted in predicting child-related paternal stresses. While fathers in a poor alliance reported more stress, stress was unrelated to their children's illnesses; for fathers in a moderate to strong alliance, illness and stress were positively correlated. Even minor child illnesses appear to be a source of stress for parents.

Cardiovascular effects of xylazine and detomidine in horses

The cardiovascular effects of xylazine and detomidine in horses were studied. Six horses were given each of the following 5 treatments, at 1-week intervals: xylazine, 1.1 mg/kg, IV; xylazine, 2.2 mg/kg, IM; detomidine, 0.01 mg/kg, IV; detomidine, 0.02 mg/kg, IV; and detomidine, 0.04 mg/kg, IM. All treatments resulted in significantly decreased heart rate, increased incidence of atrioventricular block, and decreased cardiac output and cardiac index; cardiac output and cardiac index were lowest following IV administration of 0.02 mg of detomidine/kg. Mean arterial pressure was significantly reduced for various periods with all treatments; however, IV administration of 0.02 mg of detomidine/kg caused hypertension initially. Systemic vascular resistance was increased by all treatments. Indices of ventricular contractility and relaxation, +dP/dt and -dP/dt, were significantly depressed by all treatments. Significant changes were not detected in stroke volume or ejection fraction. The PCV was significantly reduced by all treatments. Respiratory rate was significantly decreased with all treatments, but arterial carbon dioxide tension did not change. Arterial oxygen tension was significantly decreased briefly with the 3 IV treatments only.

Hemodynamic effects of carbon dioxide during intermittent positive-pressure ventilation in horses

The hemodynamic effects of high arterial carbon dioxide pressure (PaCO2) during anesthesia in horses were studied. Eight horses were anesthetized with xylazine, guaifenesin, and thiamylal, and were maintained with halothane in oxygen (end-tidal halothane concentration = 1.15%). Baseline data were collected while the horses were breathing spontaneously; then the horses were subjected to intermittent positive-pressure ventilation, and data were collected during normocapnia (PaCO2, 35 to 45 mm of Hg), moderate hypercapnia (PaCO2, 60 to 70 mm of Hg), and severe hypercapnia (PaCO2, 75 to 85 mm of Hg). Hypercapnia was induced by adding carbon dioxide to the inspired gas mixture. Moderate and severe hypercapnia were associated with significant (P less than 0.05) increases in aortic blood pressure, left ventricular systolic pressure, cardiac output, stroke volume, maximal rate of increase and decrease in left ventricular pressure (positive and negative dP/dtmax, respectively), and median arterial blood flow, and decreased time constant for ventricular relaxation. These hemodynamic changes were accompanied by increased plasma epinephrine and norepinephrine concentrations. Administration of the beta-blocking drug, propranolol hydrochloride, markedly depressed the response to hypercapnia. This study confirmed that in horses, hypercapnia is associated with augmentation of cardiovascular function.

Effects of acute hyperventilation on serum potassium in the dog

The effects of increasing respiratory rates on arterial pH, PaCO2, HCO3, and potassium (K) were measured in normal anesthetized dogs. Hyperventilation resulted in increased pH, decreased PaCO2, decreased HCO3, and decreased K compared with those parameters in spontaneously breathing dogs. The changes were related quantitatively: each 10 mmHg decrease in PaCO2 was associated with a pH increase of 0.1, a HCO3 decrease of 2.0 mEq/L, and a K decrease of 0.4 mEq/L. There were no cardiac arrhythmias or clinical signs of hypokalemia. After termination of hyperventilation, serum K was slower to return to control values than PaCO2. The ratio of the duration of hyperventilation to the time required for return of serum K to control was 0.67.

Cardiopulmonary effects of position in conscious cattle

The cardiopulmonary effects of 4 positions (standing, right lateral, left lateral, and dorsal recumbency) were evaluated in conscious cattle in which no sedatives or anesthetic drugs were given. Each position was maintained for 30 minutes, during which time there were no significant changes in heart rate, respiratory rate, mean arterial blood pressure, arterial pH, PaCO2, arterial base excess, or venous blood gas values. Significant decreases in PaO2 developed when cattle were in lateral positions and dorsal recumbency. Cardiac index was unchanged in all positions, except in dorsal recumbency at 30 minutes, when it was significantly decreased.

Sex differences in school-aged children with pervasive attention deficit hyperactivity disorder

This study investigated 54 children (37 boys and 17 girls) with cross-situational attention deficit hyperactivity disorder (ADHD) to determine whether there are sex differences in the expression of either the primary or secondary symptomatology of ADHD. Results indicated that the male and female ADHD groups were strikingly similar on all measures of primary (impulsivity, inattention, and overactivity) and secondary (learning problems, externalizing symptoms, internalizing symptoms, peer relationship difficulties, and self-perceptions) symptomatology included in this study. The lack of significant sex differences conflicts with prior reports in the literature, and these conflicting results are discussed in terms of differences in inclusion criteria. Implications for understanding the long-term outcome of ADHD in girls are also discussed.

Evaluation of creatine kinase and lactate dehydrogenase activities in clinically normal and abnormal equine joints

Creatine kinase (CK) and lactate dehydrogenase (LD) enzyme activities and isoenzymes were determined for synovial fluid, synovial membrane, and articular cartilage from 24 clinically normal equine tarsocrural (tibiotarsal) and femoropatellar joints. All 3 tissues contained LD isoenzymes LD1 to LD5, and CK isoenzymes BB and MM. The CK isoenzyme MB was not found. The similarities in isoenzyme composition of these 3 tissues made differentiation of the source of LD and CK impossible by isoenzyme pattern alone. Reference values for the total enzyme activities of specific joint tissues also had wide variations. The wide variation in activities, as determined by the enzymatic analysis of synovial fluid and a lack of tissue specificity in clinically normal equine joint tissue, indicated that those values were not predictive for the extent and type of tissue damage in equine joint disease. This hypothesis was confirmed when synovial fluids from 22 abnormal joints were analyzed for LD isoenzymes and total enzyme activity. The various causes of the joint problems were not distinguishable.

Nephelometric determination of serum amylase and lipase in naturally occurring azotemia in the dog

Serum amylase and lipase were measured in 32 healthy dogs and in 55 dogs with serum urea nitrogen values greater than 40 mg/dl, using a nephelometric analyzer (Coleman analyzer model 91). Mean serum amylase and lipase values in normal dogs were 1,085.48 units and 3.98 units, respectively. In dogs with azotemia, the mean serum amylase and lipase values were 1,822.79 units and 12.57 units, respectively. Serum urea nitrogen values could not be correlated with amylase or lipase values.

Effect of intra-articular injection of orgotein and saline solution on equine synovia

Orgotein was injected into the right intercarpal joint of each of 8 horses; the corresponding left joint was left alone (not injected) or was given an injection of normal saline solution. Injection with orgotein caused a transient, marked inflammatory response, evidenced by clinical signs and by increased leukocytes and total protein in the synovia (synovial fluid). Leukocyte numbers and total protein concentration were increased (P less than 0.010) in the orgotein-injected joints within 24 hours. However, saline solution alone also elicited a marked inflammatory response, manifested by increased leukocyte count and total protein concentration. By 7 days, leukocyte and total protein values had returned to approximately base line in all joints.

Analysis of Equine Thoracic Fluid

Eighteen clinically normal horses were used to study the characteristics of normal thoracic fluid. Thoracic fluid was obtained from each horse and was found to be similar to equine abdominal fluid. Total leukocytes averaged 3994/ul, total protein 1.8 g/dl, and specific gravity 1.015. Analysis of thoracic fluid from 16 horses with clinical signs of thoracic disease showed abnormalities in every case. Thoracic fluid analysis alone determined a specific diagnosis in 50% of the cases.