Efficacy of ipecac and activated charcoal/cathartic. Prevention of salicylate absorption in a simulated overdose.

Twelve adult volunteers were given 24 81-mg aspirin tablets and were randomly assigned into the following treatment groups: (1) control aspirin, (2) 30 mL of ipecac repeated if vomiting not induced, (3) 60 g of activated charcoal per 15 g of magnesium sulfate (MgSO4), and (4) ipecac repeated if needed, followed by activated charcoal/MgSO4 given 1 1/2 hours after the last vomiting episode. All treatments began 60 minutes following aspirin ingestion. Urine was collected for 48 hours for percent total salicylate excretion. Mean +/- SD recovery of salicylate from urine was as follows: aspirin, 96.3% +/- 7.5%; ipecac 70.3% +/- 11.8%, activated charcoal/MgSO4, 56.4% +/- 12%; and ipecac and activated charcoal/MgSO4, 72.4% +/- 14.1%. Ten subjects completed the study. In group 4, eight of ten subjects vomited the activated charcoal/MgSO4 immediately, making statistical analysis impossible. Analysis revealed that activated charcoal/MgSO4 significantly lowered the absorption of aspirin compared with the control and ipecac-treated groups. Furthermore, ipecac significantly lowered aspirin absorption compared with the control group. We conclude that activated charcoal/MgSO4 used alone is superior to the other treatment modalities at inhibiting the absorption of multiple aspirin tablets.

Thoracolaryngeal reflex latencies in Thoroughbred horses with recurrent laryngeal neuropathy.

Electrolaryngeography was used to study the latencies of the thoracolaryngeal adductor reflex in Thoroughbred horses with and without recurrent laryngeal neuropathy (RLN). Latencies were compared in horses with grades 1 and 2 RLN, diagnosed by endoscopy in resting horses. The reliability of the measurements, effect of sedation and correlations of latencies with age of the horse were also studied. There was no effect of sedation on reflex latency periods. The latency of the reflex period measured to a convolved peak of the electromyographic response was significantly different in horses with grades 1 and 2 disease; medians and quartile ranges were 0.067 (0.065-0.073) and 0.072 (0.068-0.074) s, respectively (P<0.05). Significant associations were found between reflex latencies and both horse age and the grade of RLN. Reflex latency measurements are reliable and sensitive, and may assist with the clinical appraisal of Thoroughbred horses with RLN.

Reliability of cardiorespiratory measurements with a new ergospirometer during intense treadmill exercise in Thoroughbred horses.

This study investigated the reliability of measurements with a new equine ergospirometer (Quadflow). Heart rate and blood lactate responses during exercise in horses wearing the Quadflow and an open flow mask were also compared. The mean percentage error of the oxygen uptake measurements was 8.2% (range 2.1-12.5%). Percent error for peak expiratory flow rates ranged from 6.1% to 9.4 %, and for minute ventilation from 2.5% to 7.4%. The coefficients of variation of the means of four measurements in two horses exercising continuously at 9.0 m/s were <5% for variables related to pulmonary ventilation, and was 7.7% for oxygen uptake. The Quadflow mask resulted in small increases in blood lactate concentration and relative heart rate during submaximal exercise. It was concluded that between- and within-test reliability statistics for important measurements in equine clinical exercise testing were acceptable for routine use in a veterinary practice or research laboratory.

Volume of distribution of theophylline in acute exacerbations of reversible airway disease. Effect of body weight.

The literature is unclear as to whether theophylline loading doses should be based on total body weight (TBW) or ideal body weight (IBW). The objective of this study was to determine the most appropriate body weight for estimation of volume of distribution (Vd) in calculating theophylline loading dose in patients with acute bronchospasm. Fifty-four adult patients with acute bronchospasm requiring intravenous (IV) theophylline therapy were entered into the study. Patients were randomized into three theophylline loading dose groups based on (1) TBW, (2) IBW, and (3) adjusted body weight (ABW). Initial serum theophylline concentrations were used to determine an IV loading dose to reach a plasma concentration of 12 to 15 micrograms/ml. Percent prediction error was used to determine the appropriateness of each dosing group. Volumes of distribution were also determined for each group. There was a statistically significant difference at p less than 0.01 in the percent prediction error when patients in the TBW group were compared to the IBW and ABW groups. A statistically significant difference in the Vd was observed between the TBW and IBW group (p less than 0.01). We conclude that IBW is more appropriate than TBW or ABW for determining theophylline loading dose in patients with acute bronchospasm.

Human tumor models in the severe combined immune deficient (scid) mouse.

PURPOSE: To test a number of established human tumor cell lines and early passage breast cancer (UACC2150) and melanoma cells (UACC1273) for growth in the scid mouse and the tumors' response to conventional chemotherapeutic drugs. METHODS: Established melanoma (A375, C81-61), colon (SW480), lung (A549), lymphomoblastoid leukemia (LCL-B), promyelocytic leukemia (HL60), prostate (PC-3, DU145), and breast (MCF7) cell lines were injected at subcutaneous (s.c.), intraperitoneal (i.p.), or mammary fat pad (MFP) sites. Tumor volume growth curves and survival curves were established for the various tumor cell lines. Carmustine (BCNU), cisplatin (CDDP), cyclophosphamide (CPA), doxorubicin, dacarbazine (DTIC), tamoxifen and vincristine were injected s.c. or i.p.. The chemotherapeutic drug effects on tumor volumes and survival were determined. RESULTS: Tumor growth occurred with each cell type. After i.p. injection, 90% mortality occurred within 26 to 60 days except for the early passage melanoma cell line UACC1273 with which mortality occurred within approximately 90 days. In the MCF7 breast model, treatment with tamoxifen (P < 0.001) and CPA (P < 0.0001) resulted in significant tumor growth delay compared with control groups. BCNU and CDDP resulted in significant tumor growth delays relative to control in SW480 colon cancer (P < 0.0014) and A375 melanoma (P < 0.0001) models, respectively. CPA and doxorubicin improved survival in the HL60 leukemia model (P = 0.0018). CONCLUSIONS: These scid mouse human tumor models appear to reflect the clinical situation in that clinically active chemotherapeutic drugs are similarly active in the scid mouse models. Therefore, the scid mouse models may be useful for testing new chemotherapeutic agents against various human cancer types.

Hydrophobic forces between protein molecules in aqueous solutions of concentrated electrolyte.

Protein-protein interactions have been measured for a mutant (D101F) lysozyme and for native lysozyme in concentrated solutions of ammonium sulfate at pH 7 and sodium chloride at pH 4.5. In the mutant lysozyme, a surface aspartate residue has been replaced with a hydrophobic phenylalanine residue. The protein-protein interactions of D101F lysozyme are more attractive than those of native lysozyme for all conditions studied. The salt-induced attraction is correlated with a solvation potential of mean force given by the work required to desolvate the part of the protein surfaces that is buried by the protein-protein interaction. This work is proportional to the aqueous surface-tension increment of the salt and the fractional non-polar surface coverage of the protein. Experimental measurements of osmotic second virial coefficients validate a proposed potential of mean force that ascribes the salt-induced attraction between protein molecules to an enhancement of the hydrophobic attraction. This model provides a first approximation for predicting the protein-protein potential of mean force in concentrated aqueous electrolyte solutions; this potential is useful for determining solution conditions favorable for protein crystallization.

Aspects of the epidemiology of nematode infections in a cow-calf herd in Ontario.

On May 29, 1980, 108 cows and calves were placed on a 20 hectare pasture until October 26, except that from September 18 to October 2 they were in a barn. Every two weeks during the total period, fecal samples were taken from 17 cows and 14 calves and herbage samples were collected from the pasture. Parasite fecal egg counts were estimated using the Cornell-Wisconsin centrifugation technique and herbage infective larvae by a modified Sandwich technique. Daily maximum and minimum air temperature and precipitation were recorded. The principal parasite egg found was the trichostrongyle-strongyle morulate, oval-shaped egg referred to as a gastrointestinal nematode (GIN) egg. The mean GIN egg/g of feces for cows varied from 14.2 to 23.9 and for calves it rose from 0.2 in the spring to 134.8 in the fall. Nematodirus, Trichuris, Strongyloides, Moniezia and coccidia were also found. Larvae were recovered first in July, with the greatest number, over 2000/kg of dry weight of herbage, in September and were primarily Cooperia and Ostertagia.

Exposure of motor vehicle examiners to carbon monoxide: a historical prospective mortality study.

The National Institute for Occupational Safety and Health (NIOSH) investigated the health effects of chronic exposure to low concentrations of carbon monoxide by conducting a historical prospective cohort study of mortality patterns among 1,558 white male motor vehicle examiners who were employed in New Jersey for a minimum of 6 months between 1944 and 1973. Industrial hygiene surveys indicated that the examiners were exposed to carbon monoxide at a time-weighted average (TWA) of 10-24 ppm; the exposure level recommended by NIOSH is 35 ppm TWA. A modified life table technique was used to calculate cause-specific expected deaths for the cohort adjusted for age and calendar time periods. The expected deaths were compared to the number of observed deaths through August 1973. The cohort demonstrated a slight overall increase in cardiovascular disease deaths (124 observed vs. 118.4 expected), but a more pronounced excess was observed within the first 10 yr. following employment (28 observed vs. 20.9 expected). A statistically significant excess of cancer mortality was found for motor vehicle examiners after 30 yr latency (13 observed vs. 6.9 expected, P < 0.5); this excess, however, was not confined to any particular organ site. The number of deaths due to accidents was significantly lower than expected (8 observed vs. 19.6 expected, P < .01).

Atypical interstitial pneumonia in cattle.

Atypical interstitial pneumonia is described as two clinical syndromes in young cattle. One syndrome occurs in animals which have clinical evidence of pneumonic pasteurellosis, responds initially to treatment for one to two days and then develops acute signs of atypical interstitial pneumonia. The second syndrome involves acute respiratory distress in young calves due to atypical interstitial pneumonia with antecedents of enzootic pneumonia. The postmortem lesions are described along with discussion of the possible pathogenesis of the condition and treatment.

Controlled breeding of dairy cows with cloprostenol.

The percentage of dairy cows that were mated and became pregnant during a 42 day breeding period was not significantly different when animals were routinely observed for estrus and mated when detected (71%, n = 56), inseminated at estrus following a single injection of cloprostenol (72%, n = 29), or inseminated at a fixed time after two cloprostenol treatments 11 days apart (69%, n = 28). However, 11 cows in the control group were not detected and mated during the breeding period and inclusion of these animals reduced the actual pregnancy rate to 60%. Results indicated that a controlled breeding program could have practical application in dairy herds but should be used with caution. Practitioners must evaluate management programs and decide, in consultation with the herdsman, if the introduction of controlled breeding technology might be advantageous.

The effect of retained placenta and metritis complex on reproductive performance in dairy cattle -- a case control study.

A study of the computer stored records of 293 dairy cows and 652 calvings reveals the effects of retained placenta and metritis complex on reproductive performance. The overall incidence rate of retained placenta was 11.2%. Retained placenta was 4.6 times more likely to occur following twin births than following single births. Most cases of retained placenta occurred during the fall. Forty-five percent of that seasonal increase was explained by an increased number of calvings. Metritis complex was diagnosed following 54.8% of retained placenta cases. Retained placenta alone did not significantly impair reproductive performance. Metritis complex, in the presence or absence of retained placenta, caused a significant (P

Lung sounds in cattle, horses, sheep and goats.

The purpose of this paper is to emphasize the importance of pulmonary auscultation for the clinician. It suggests a clarification and simplification of the terminology to be used which would be helpful to veterinary students and allow better communications between veterinarians. The interpretation of these sounds and the relationships to conditions and diseases of the lungs in cattle, horses, sheep and goats are discussed.

Verminous Pneumonia in Adult Dairy Cows in Southern Ontario due to Dictyocaulus viviparus.

An outbreak of verminous pneumonia due to Dictyocaulus viviparus in a herd of mature, lactating, dairy cows in southern Ontario is described. The fact that the herd had been closed to new additions for ten years and had never experienced clinical disease due to D. viviparus in the past makes the occurrence of this herd problem difficult to explain. Correlation of fecal Baermann analysis for D. viviparus larvae with the progress of anthelmintic treatment is discussed. It is suggested that certain climatological variations in combination with unique, immunological aspects of D. viviparus infection may have contributed to the development of clinical disease in this herd.