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Biomedical subjects

J Verhoeff

Publications and source records attributed to J Verhoeff.

At least 37 records · Page 2Linked to original sources
PubMed1993

Antibodies against nematodes in serum, milk and bulk milk samples as possible estimators of infection in dairy cows.

Antibodies against Ostertagia spp., Cooperia spp. and Dictyocaulus viviparus were assessed in serum and individual milk samples of cows and in bulk milk samples from the refrigerating tank. Titres in milk samples were related to serum titers, but also influenced by milk yield, lactation stage and age of the cow. Correlation coefficients between serum and individual milk samples were highly significant, and varied from 0.42 to 0.56. Correlations between herd means of serum titres and herd means of individual milk titres varied from 0.41 to 0.61, and those between herd means of serum titres and means of bulk milk samples from 0.43 to 0.67. Finally, the correlations between herd means of individual milk samples and means of bulk milk samples varied from 0.52 to 0.82. This variation was dependent upon worm species and whether or not correction for milk yield was applied. The discrimination of herds was evaluated by the between/within herd ratio of variances. F-values for all types of samples were highly significant, and at least as high for milk samples as for serum samples. If, as has been shown for serum samples, a positive relationship exists between the milk yield response to anthelmintic treatment and the mean herd titre of milk samples or bulk milk samples, assessment of these titres could offer a rational basis for treatment of dairy cows.

Age Factors↗
PubMed1993

Risk of infection with bovine herpes virus 1 (BHV1): a review.

Bovine Herpes Virus 1 (BHV1) consists of three subtypes, which probably differ in their epizootiological characteristics. BHV1 subtypes 1 and 2a are mainly associated with the respiratory form of the disease (IBR), subtype 2b with IPV/IBP, and subtype 3 with encephalitis. BHV1 subtype 1 is excreted in high titres in nasal secretions and spreads more effectively than the other subtypes. Cattle are the only significant source of viral spread. Although other species may become infected, they probably do not contribute to the spread of BHV1. Airborne transmission or spread of the virus by humans is believed to be of minor importance.

Animals↗
PubMed1992

Radiographic and radionuclide lung perfusion imaging in healthy calves and calves naturally infected with bovine respiratory syncytial virus.

Nine calves between three and 18 weeks old with serologically confirmed natural bovine respiratory syncytial virus infection were examined clinically, radiographically and by radionuclide lung perfusion imaging. The results were compared with those from seven healthy calves. The diseased calves were euthanased and examined pathologically, virologically and bacteriologically. The clinical signs indicated that the disease was in an acute stage. Radiography of the diseased animals revealed cysts, corresponding morphologically with bullous emphysema, and infiltrations roughly corresponding in distribution with atelectatic and, or, pneumonic areas. Radionuclide lung perfusion imaging revealed no perfusion shifts between the left and right lungs and a normal perfusion pattern in five of the nine diseased calves. The abnormalities in the perfusion patterns of three calves were probably caused by anatomical disorders such as cysts and pleural adhesions, but no cause of the abnormality could be found in one calf. These findings suggest that in calves infected with bovine respiratory syncytial virus, the normal perfusion pattern is maintained until anatomical disorders occur. The pathological examination and radiography revealed that the cranioventral lung fields were particularly poorly ventilated. This finding and the normal perfusion pattern indicate that these parts of the lungs are probably the sites where shuntings and perfusion-ventilation mismatchings occur.

Animals↗
PubMed1990

Effect of naturally occurring nematode infections on growth performance of first-season grazing calves.

Liveweight of calves on 89 dairy farms was measured at the end of the grazing season and related per herd to the level of exposure to nematode infection during the grazing season. There were significant between-herd variations in antibody titres against Ostertagia spp., Cooperia spp. and Dictyocaulus viviparus as well as in pepsinogen values. All but six herds (93.1%) had gastrointestinal nematode infections, as measured by faecal egg counts in September. Faecal samples of 17 herds (19.3%) contained lungworm larvae in September. Liveweight of calves per herd deviated from -68.1 kg to +84.1 kg from the age-adjusted population mean after their first grazing season. Growth performance up to the time of liveweight measurements was significantly correlated negatively with several serological and parasitological parameters. Data could be fitted by means of both linear and segmented curvilinear regression. Antibody titre against Cooperia spp. and gastrointestinal nematode egg output measured in September accounted for 3.1% (P less than 0.10) and 6.7% (P less than 0.05), respectively, of the variation in growth performance among herds. Certain infection parameters, when combined, accounted for 9.2% of this variation; these were antibody titre against Cooperia spp. and larval counts for both gastrointestinal nematodes and lungworm. Adding certain management factors to these infection parameters resulted in a model explaining 27.6% of the observed variation in growth performance among herds. These factors were supplementary feeding, lungworm vaccination, anthelmintic treatment at housing, date of housing and herd age.

Age Factors↗
PubMed1988

Clinical signs following experimental lungworm infection and natural bovine respiratory syncytial virus infection in calves.

Similar clinical signs have been reported in calves infected either by Dictyocaulus viviparus or bovine respiratory syncytial virus. Three experiments were carried out to establish the clinical picture and the course of the disease in animals with these infections. The clinical signs of calves infected with lungworm included coughing, nasal discharge, tachypnoea, abdominal breathing and pyrexia, and auscultation of their lungs revealed increased bronchial sounds. Similar signs were also observed after infection with bovine respiratory syncytial virus, but the signs were more acute and resolved more rapidly than in animals infected with lungworm larvae. Calves infected with lungworm had more serious clinical signs after infection with bovine respiratory syncytial virus than calves, which were not infected with lungworm.

Animals↗
PubMed1988

Mismatching of ventilation and perfusion in calves with natural bovine respiratory syncytial virus infection.

The cause of arterial hypoxia during natural infection with bovine respiratory syncytial virus was studied in seven calves (three to nine months of age) originating from five herds with respiratory tract disease and serological evidence of infection with the virus. Blood gas values were measured during ambient air breathing and during 100 per cent oxygen breathing. The percentages of contribution to the arterial hypoxia from alveolar hypoventilation, mismatching of ventilation and perfusion, and right-to-left shunting were calculated from the measured parameters. Calculated percentages of total venous admixture varied from 14 per cent of cardiac output in relatively mild cases to 48 per cent in the worst affected animal. This venous admixture had been caused mainly by right-to-left shunting of blood, while mismatching of ventilation and perfusion became important in the more severely affected animals. Alveolar hypoventilation was only important in the worst affected animal.

Animals↗
PubMed1987

Effects of two glucocorticoids on milk yield and biochemical measurements in healthy and ketotic cows.

The effects of two glucocorticoid compounds (Dexamedium; Intervet. Voreen; Boehringer Ingelheim) were tested in 20 healthy and 28 ketotic dairy cows. Both compounds induced an increased blood glucose concentration and a temporary decrease in the milk yield of healthy dairy cows. Dexamedium reduced the milk yield only of cows producing 25 or more kg milk daily. Of 28 ketotic cows 22 were treated with one of the two glucocorticoid compounds, while the remaining six were treated orally with propylene glycol. After treatment all but one of the cows improved clinically within one week. Biochemical analysis of blood samples revealed that after treatment with any of the three therapeutic compounds some animals responded inadequately to therapy or relapsed after initial recovery.

Acidosis↗
PubMed1986

Clenbuterol hydrochloride in calves with a natural bovine respiratory syncytial virus infection.

The effect of clenbuterol hydrochloride on the course of disease in calves with a natural bovine respiratory syncytial virus infection was examined. Six calves (three to nine months of age) originating from four herds with respiratory tract disease and serological evidence of a bovine respiratory syncytial virus infection were used in this study. The calves were injected intravenously with clenbuterol hydrochloride. The effect of clenbuterol on the course of disease was measured using the PO2 in blood taken from an indwelling canula inserted in the caudal auricular artery and by clinical signs. Clenbuterol did not improve clinical signs. After clenbuterol administration arterial PO2 values decreased significantly in five out of six patients. Six to eight hours after medication the mean arterial PO2 values were higher than initial values. The moderate positive effect of clenbuterol after six to eight hours may be caused by enhancing ciliary activity and by the secretolytic activity of clenbuterol.

Airway Resistance↗
PubMed1986

Flunixin meglumine in calves with natural bovine respiratory syncytial virus infection.

Twenty-three calves (three to eight months of age) with serological evidence of bovine respiratory syncytial virus infection were used in this study. The calves originated from four herds with respiratory tract disease. In a double blind trial the calves were injected intravenously with either flunixin meglumine (2 mg/kg body weight) or with a placebo. The effect on the course of disease was measured using the PO2 in capillary blood samples from the ears of the calves and by the effect on body temperature and respiratory rate. Mean body temperature fell significantly in the flunixin meglumine treated group. Statistically significant differences were not found between the treated and control group during the seven-day examination period.

Animals↗
PubMed1986

[On information. An essay].

We witnessed the stormy development of electronics during the last few years. The effects of this so-called micro-electronic revolution have gradually become noticeable in anyone's everyday life. This will penetrate into all our lives at an accelerated rate during the present century. The computer may be used as an automatic tool or as an independently operating instrument. In the former case (processing of texts and diagrams is an instance to bear in mind), man should see to it that he uses the tool as a creative individual himself. In the latter case, the strong features of the computer should be made use of. These are: Being able to wait patiently and attentively, which may stand in good stead in monitoring and alarming functions. Being able to react rapidly and accurately, a good quality in controlling a variety of well-defined processes in which the human ability to react fails. The ability to cope with and treat large amounts of data, in which the weak side of the computer should be taken into account, namely the assessment and recognition of situations. A good feature of these developments consists in the fact that man can dispose of a capable electronic slave. The unsatisfactory aspect is that a stupid electronic dictator may be imposed on man.

Computers↗
PubMed1985

Onion poisoning of young cattle.

Eighty-five cattle (calves and yearlings) were allowed 1000 kg of onions (Allium cepa) a day. Signs of poisoning were observed after five days; 22 animals were affected, one fatally. New illnesses continued to occur for five days after the withdrawal of onions from the diet. Clinical signs included inappetance, tachycardia, staggering and collapse, with jaundiced conjunctivae and haemoglobinuria. Haemolytic anaemia with Heinz bodies in the red cells and leucocytosis were demonstrated.

Allium↗
PubMed1985

Spontaneous bovine respiratory syncytial virus infections in calves: arterial blood gas, pH and bicarbonate values.

Arterial blood gas values of 12 calves in the acute stage of a bovine respiratory syncytial virus infection were compared with corresponding values of 11 healthy calves. The patients appeared to be severely hypoxic. Mean (+/- sd) arterial oxygen tension (PaO2) values of patients and healthy calves were 7.7 +/- 1.9 and 14.2 +/- 1.5 kPa, respectively. Hypercapnia was present in only three of the diseased calves. These findings are in close agreement with findings in young children with respiratory syncytial virus infections. It is argued that the pathophysiological mechanism involved probably is a ventilation-perfusion abnormality.

Animals↗
PubMed1985

Effects of trenbolone acetate and propylene glycol on pregnancy toxaemia in ewes.

Eleven ewes with pregnancy toxaemia were monitored clinically and biochemically after daily treatment with trenbolone acetate (30 mg) and propylene glycol (twice daily 100 ml), for at least one week. The clinical signs of pregnancy toxaemia at first examination were less severe than those described in ewes in other countries. After the first treatment, the appetite improved in nine ewes, blood glucose levels increased in 10 ewes and blood ketone body concentrations decreased in nine animals. A statistically significant decrease in mean ketone body levels was found between the day of first examination and the second day thereafter. Four animals recovered before lambing (group 1). One animal lambed one day after the first treatment and recovered. In the remaining ewes clinical and biochemical improvement did not last long. Three of these animals did not recover until after lambing (group 2) and three animals died (group 3). In three animals of group 2 and two animals of group 3 an increase of serum activities of lactate dehydrogenase, sorbitol dehydrogenase, gamma glutamyl transferase and alkaline phosphatase was found. In two necropsied animals of group 3 a severe fatty degeneration of the liver was found. Treatment of pregnancy toxaemia with trenbolone acetate and propylene glycol appeared to have some positive effect in mild cases. In more advanced cases the time of parturition is the crucial factor leading to recovery.

Animals↗
PubMed1985

Correlation of a disease scoring system with arterial PO2 values in respiratory syncytial virus infection in calves.

The mean arterial PO2 value measured in blood obtained by puncture of the brachial artery of 20 calves with acute clinical signs of a bovine respiratory syncytial virus (BRSV) infection was 8.4 +/- 1.9 kPa. The values differed significantly from arterial PO2 values of eleven healthy calves (mean 14.2 +/- 1.5 kPa). A disease scoring system is presented based on the type of respiration and the findings on auscultation. A high correlation (r = -0.87) was found between disease scores and arterial PO2 values. This indicates that the described disease scoring system can be a useful tool in the evaluation of the severity and course of BRSV infections in calves, and could be used for evaluating the efficacy of BRSV vaccines in the field. The course of disease was studied in 127 calves with clinical signs of serologically proven BRSV infection. Animals with mild respiratory signs during the acute phase of disease remained free of severe respiratory problems until the end of a 35-day examination period. Mean disease scores indicated that animals with severe signs in the acute phase often developed persistent respiratory problems.

Animals↗
PubMed1985

Respiratory syncytial virus pneumonia in Friesian calves: physiological findings.

Clinical, serological and physiological values were measured during and after naturally occurring respiratory syncytial virus pneumonia in four Friesian calves weighing between 120 and 160 kg. Clinical and serological findings were in agreement with the description of spontaneous calf pneumonia, associated with respiratory syncytial virus infection. Pulmonary function values, recorded one, eight, 15 and 57 days after the clinical onset of the disease, provided good evidence that the clinical syndrome associated with respiratory syncytial virus infection in Friesian cattle is at first an acute obstructive disease which is progressively replaced by a moderate subclinical restrictive disease.

Animals↗
PubMed1984

Prevention of bovine respiratory syncytial virus infection and clinical disease by vaccination.

A double blind field trial was carried out with a live attenuated bovine respiratory syncytial virus vaccine. The trial involved 530 calves, two to 10 months old, on 27 dairy farms, where respiratory problems due to bovine respiratory syncytial virus infections had been observed during the preceding year. In 17 herds either all calves were vaccinated (nine groups) or all calves received a placebo (eight groups). In 10 herds half the number of calves were vaccinated and the other half kept as non-vaccinated controls. Calves were vaccinated intramuscularly twice with an interval of four to five weeks. These groups were under regular clinical observation and animals were tested periodically for antibodies to bovine respiratory syncytial virus and parainfluenza type 3 virus. Serological examination indicated that no bovine respiratory syncytial virus infection had occurred prior to the first vaccination in August. Vaccination did not cause adverse reactions. Low concentrations of neutralising and complement fixing antibodies were induced by vaccination and a sharp increase of antibody titres was observed after natural infection of vaccinated animals. Infections with bovine respiratory syncytial virus occurred in six out of eight non-vaccinated groups, in nine out of 10 partly vaccinated groups and in only two out of nine completely vaccinated groups. Virus infection in completely vaccinated groups was significantly reduced compared with partly vaccinated and non-vaccinated groups. The incidence of bovine respiratory syncytial virus lower respiratory disease was significantly reduced in completely vaccinated groups compared to non-vaccinated groups. Generally only mild signs of upper respiratory disease were present in completely vaccinated groups after bovine respiratory syncytial virus infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

BRS virus, PI3 virus and BHV1 infections of young stock on self-contained dairy farms: epidemiological and clinical findings.

The role of bovine respiratory syncytial virus, parainfluenza type 3 virus and bovine herpesvirus 1 as disease agents in 28 groups of young cattle on 19 dairy farms which raised their own replacements was investigated. Bovine respiratory syncytial virus infections occurred in 27, parainfluenza type 3 virus infections in all and bovine herpesvirus 1 infections in three of the 28 groups. Some infections were accompanied by clinical signs while others were entirely subclinical. Clinical respiratory disease was observed on 25 occasions in 20 of the groups. Respiratory disease was associated with a bovine respiratory syncytial virus infection on 15 occasions with parainfluenza type 3 virus infection in four cases and with bovine herpesvirus 1 infection in two cases. In four cases there was no association between the respiratory disease and any of the four virus infections. Bovine respiratory syncytial virus infections caused more serious respiratory problems than parainfluenza type 3 virus infections.

Age Factors↗