An improved method for tail-flick testing with adjustment for tail-skin temperature

The tail-skin temperature is an important factor in determining tail-flick latency to noxious radiant heat in rats and mice. A simple, non-invasive method for recording the tail-skin temperature during conventional tail-flick testing is described. The method is conveniently performed during conventional tail-flick testing. It does not require additional handling of the animals, and it is not stressful. The method utilizes a small-sized thermocouple which is brought in contact with the dorsal surface of the tail close to the area exposed to the radiant heat stimulus. A computer based system is used to record the temperature and control the tail-flick apparatus. Continuous monitoring of skin temperature showed that the temperature as measured 23 mm from the tip of the tail agreed well with skin temperature in the position where the beam was focused during tail-flick testing (13 mm from the tip). The skin temperature closer to the base of the tail (100 mm from the tip) showed considerably more deviation from the temperature 13 mm from the tip. Temperature measurements close to the heated area gave a higher degree of correlation between recorded temperature and tail-flick latencies than did temperature measurements closer to the base of the tail. These results provide further support for the contention that tail-skin temperature is an important factor when assessing nociception by means of the tail-flick test, and demonstrate that the temperature should be measured as close to the heated area as possible.

Rapid isolation of K88+ Escherichia coli by using immunomagnetic particles

Superparamagnetic polymer particles precoated with sheep anti-mouse immunoglobulin G were coated with immunoglobulin G2 monoclonal antibodies to the K88 antigen of Escherichia coli (MAb-K88). These immunomagnetic particles (IMP) were used for isolation and identification of K88 antigen-positive (K88+) E. coli. The bacteria presenting the K88 antigen were easily isolated in almost pure culture from a mixed culture of five different O serogroups of E. coli. Nonspecific binding of K88 antigen-negative (K88-) E. coli to the IMP was not observed. The sensitivity of the test to detect K88+ E. coli was found to be 4,000 CFU/ml with fluorescence microscopy. When bacteria attached to the MAb-K88 IMP were grown on blood agar, about 20% of the initial number of CFU was recovered. The test is promising as a rapid method for isolation and identification of K88+ E. coli from a mixed culture.

The role of antiepileptics in sudden death in epilepsy

In a material of sudden, unexpected death of epileptic patients treated with one or more of the anticonvulsants phenobarbitone, phenytoin and carbamazepine we found subtherapeutic drug levels in half of the cases and lethal concentrations, mainly of phenobarbitone, in one third of the cases. The results illustrate the severe consequences of noncompliance in epilepsy, and stress the value of blood drug level control.

The diagnostic value of postmortem blood glucose determinations in cases of diabetes mellitus

In 24 cases of death in diabetic coma the peripheral venous blood showed glucose levels exceeding 3.5 mg/ml (mean value 7.76 mg/ml). In a control material of deaths of other causes the blood glucose was usually low and often zero, and all values were well below the lower limit of the diabetic concentrations. The acetone contents of the diabetic blood varied widely and were of limited diagnostic value. We conclude that glucose concentrations above 3.5 mg/ml in the peripheral blood indicate that death occurred in diabetic coma.

The causes of death in fire victims

In 169 consecutive cases of autopsied fire victims about 50% had lethal levels of carboxyhemoglobin. Soot in the respiratory tract was found in about 90% of the cases. The age distribution of the fire victims showed significantly less persons in the 15-35-year group than should be expected according to the age distribution of the population, presumably due to greater agility of younger people. More than half of the fire victims had alcohol in the blood exceeding 0.05%, and alcohol intoxication should be considered accessary to many deaths in fire. The characteristic biphasic distribution of carboxyhemoglobin in fire victims together with other observations suggest that the principal causes of death are carbon monoxide followed by carbon dioxide poisoning and/or oxygen deficiency, while the influence of heat is considered to be of minor importance.

Differences in bindings to the GM1 receptor by heat-labile enterotoxin of human and porcine Escherichia coli strains

Heat-labile enterotoxin producing strains of Escherichia coli were isolated from diarrheal faeces of humans and from the jejunum of pigs which had died of diarrhea. The heat-labile enterotoxin was assayed by three different enzyme-linked immunosorbent assays (ELISA). The first assay was based upon immunological cross-reactions between the heat-labile enterotoxins of E coli and Vibrio cholerae, the second on specific E coli heat-labile enterotoxin antibodies and the third on affinity of the toxin to the presumed cell membrane receptor, the ganglioside GM1. The heat-labile enterotoxins of human and porcine origin bound equally well to the same extent in the ELISA procedure, which utilized immunological cross-reactivity between the heat-labile enterotoxins of E coli and V cholerae. The reactivity, however, was quite different in the GM1-ELISA. The binding affinity was high between GM1 and enterotoxin produced by E coli strains of human origin, whereas the binding affinity was low for enterotoxin from porcine strains.

Indigestion in young calves. VI. Studies of diarrheic calves fed milk replacers made of normal and heat-treated skim milk and whey powder

Diarrhea occurred in 12 pre-ruminant calves after the introduction of milk replacers. Six of the calves were fed a replacer made of normally treated skim milk and whey powder, while the other 6 got a replacer made of heat-treated powders, although otherwise similar to that of the first group. Abomasal curd formation was deficient in calves fed for 9 or 17 days on the heat-treated replacer (4 of 6 calves). Otherwise, no clear differences between the calves given normally treated and heat-treated replacer occurred, as regards diarrhea, bacteriological, virological, and pathomorphological findings in the intestinal tract. Rotavirus and chlamydial infections were indicated and considered as the major cause of the diarrheic condition, although bacteria, including coliforms and Pseudomonas aeruginosa, may have contributed. The milk replacers may have been involved was provoking factors.

Endogenous alcohol production by intestinal fermentation in sudden infant death

In some cases of sudden infant death syndrome (SIDS) the intestinal flora was found to be dominated by Candida albicans. Microbiologic investigations of the various organs showed the occasional presence of different Candida species, but not in the form of massive growth as in sepsis. There is no basis to assume that the activity of yeasts, first of all of Candida albicans, is a contributory factor in the occurrence of SIDS. Candida albicans was shown to produce alcohol from glucose at a rate of maximally 1 mg of alcohol per gram of intestinal content per hour. It is concluded that the intestinal production of alcohol in vivo from cases showing a Candida albicans dominated intestinal flora will not be able to surpass the normal alcohol metabolizing capacity of the liver. Thus, measurable concentrations of alcohol in the blood from such cases cannot be expected.

Antibodies to Corynebacterium pseudotuberculosis in adult goats from a naturally infected herd

Serum samples taken in 3 successive years (1977, 1978 and 1979) from adult dairy goats (Norwegian breed) originating from 1 herd were examined for antibodies to Gorynebacterium pseudotuberculosis. Both bacterial agglutination test (BAT) and hemolysis inhibition test (HIT) were used. The proportion of seropositive goats increased 10–12 % during the investigation period. In 1979 all animals were seropositive to BAT and about 95 % had antihemolysins in their sera. Twenty-two of the 23 one-year old goats recruited to the herd in 1978 were seropositive. The average age-specific titres increased up to the age of 3 years, and subsequently decreased for goats aged 4–7 years. Caseous lymphadenitis is thus regarded as a chronic infection. The effect of age on the titre values was significant at the 5 % level in 1977 and 1978 when HIT was used and in 1978 when BAT was used. During the investigation period the same 36 and 40 goats were examined every year by BAT and HIT, respectively. Intermediate to high correlations between titre values for the same goats from year to year were found.

Both BAT and HIT are suitable for sero-epidemiological investigations concerning infection with G. pseudotuberculosis in goats.

Serological, enterotoxin-producing and biochemical properties of Escherichia coli isolated from piglets with neonatal diarrhea in Norway

Altogether 235 strains of Escherichia coli isolated from jejunal content of piglets with neonatal diarrhea were examined for serological, enterotoxin-producing and certain biochemical properties. Of 198 strains examined, 84 (42 %) belonged to O-group 149, while 14 (7 %) strains belonged to each of the O-group s 8 and 64. Seventy strains (30%) could not be grouped with the sera used. The remaining strains were distributed among the following O-groups with only a few strains in each group: 2,6,9,32,45,98 and 141. Eighty out of 84 E. coli strains of O-group 149 possessed the K88 antigen and produced heat labile enterotoxin (LT). Besides, LT production was demonstrated in 3 out of 14 strains of E. coli 08. K88 antigen was demonstrated in only 1 strain not belonging to O-group 149. Among strains of E. coli 064 12 out of 14 were K99 positive. This antigen was not demonstrated in E. coli strains of other O-groups. A close relationship was demonstrated between strains of E. coli 0149 possessing the K88 antigen and the ability to ferment both raffinose and adonitol. This ability was only detected in 2 other strains of E. coli not belonging to O-group 149.

Colostral transfer in the goat of antibodies against Corynebacterium pseudotuberculosis and the antibody status of kids during the first 10 months of life

Serum and colostrum samples from goats at parturition and serum samples from their kids at 3 days and at 4, 7, 10 and 12 weeks after birth were examined for the presence of antibodies to Corynebacterium pseudotuberculosis hemolysins. The hemolysis inhibition test (HIT) was used. High correlation was found between titre values of antihemolysins in serum and colostrum of goats at parturition (correlation coefficient r = 0.83; P < 0.01). Intermediate correlation was found between antihemolysin titre in colostrum of goats and in the sera of their kids 3 days old (r = 0.56; 0.01 < P < 0.05). Furthermore, titre values for 3 day-old kids showed high correlation with the antihemolysin titres when the kids aged 4 and 7 weeks (r = 0.76 and 0.85, respectively; P < 0.01). Antihemolysin titres decreased linearly in kids from 3 days to 10 weeks old. Calculated half life of antibodies was 12 days. Most of the kids had detectable antibodies up to the age of 5–6 weeks. None of the kids were seropositive at 2½ months of age.

Serum samples collected monthly from a group of kids chosen at random, aged 7–10 months, contained antibodies to hemolysins in half of the animals at the first testing. At the age of 10 months 14 out of 15 kids were seropositive. Thus, most of the kids from this herd were exposed to G. pseudotuberculosis antigens during summer and autumn of their first year of life.

Prophylactic measures against caseous lymphadenitis is briefly discussed.

Swine dysentery: the influence of dietary vitamin E and selenium on the clinical and pathological effects of Treponema hyodysenteriae infection in pigs

Twenty-four conventionally reared pigs were divided into four equal groups and fed a basic ration deficient in vitamin E and selenium. One group was given a supplement of vitamin E and selenium. One group was given a supplement of vitamin E, another received selenium and a third received both nutrients. No supplement was given to the control group. After the pigs had been fed the different diets for 59 days they were inoculated with a pure culture of Treponema hyodysenteriae They were subsequently observed for 22 days. The inoculation resulted in outbreaks of swine dysentery in all groups. The results indicated that the administration of vitamin E supplement alone to the pigs reduced the clinical effects of T hyodysenteriae only to a minor degree. On the other hand, supplementation with selenium, either alone or with vitamin E, had a more positive effect which was most clearly illustrated by a greater weight gain during the postinoculation period.

Swine dysentery: a scanning electron microscopic investigation

An investigation by scanning electron microscope was performed on colonic specimens from 4 conventionally reared pigs, 2 of which were suffering from swine dysentery (SD) after inoculation with Treponema hyodysenteriae in pure culture. In pigs with SD dilated cryptal openings surrounded by uneven mucosa with furrows and ridgeformations were found in areas with scattered pseudomembranes. The treponemes were numerous on the mucosal surface but seemed only to penetrate damaged epithelial cells. Freeze-fractured sections from the same pigs revealed dilated crypts where the microvilli were short, irregular and markedly reduced in number possibly due to change in cell kinetics. The present study seems to indicate that epithelial attachment and penetration of treponemes are of minor importance in SD pathogenesis.

Free radical formation in gamma-irradiated 5-nitro-6-hydroxythymine at 77K: an electron spin resonance single crystal investigation

An electron spin resonance single crystal investigation of gamma-irradiated 5-nitro-6-hydroxythymine has been carried out at 77K. The primary reduced species was identified and was shown to have the unpaired electron localized on the nitro group. NO2 radicals were identified and suggested to be formed in the decay of the primary oxidation product. A third radical which shows isotropic coupling to the methyl group was identified and is suggested to be formed by the homolytic cleavage of the C-NO2 bond. A mechanism for the radical formation is proposed.

Yeasts in the rumen contents of musk oxen

The yeast flora of 16 samples of rumen contents of musk oxen (ovibos moschatus) from East Greenland was examined. Variable numbers of yeast colonies developed on agar plates incubated at 25 degrees C, the counts being up to 136000 per g (wet wt). Of the 41 strains isolated, the majority belonged to Candida and Cryptococcus; others were species of Trichosporon, Rhodotorula, Torulopsis and Pichia. Very few colonies appeared on plates incubated at 37 degrees C, and only one species of Candida was isolated. Samples of rumen contents kept at about 5 degrees C for about 3 years contained a much greater number of yeasts, up to several million per g (wet wt) being counted on agar plates incubated at 25, 15 and 5 degrees C. The 30 strains isolated were of only three species of Candida, and none were obligate psychrophils.

The distribution of chlorpromazine between plasma and erythrocytes

Chlorpromazine is found to be taken up by the erythrocytes in a dissociable binding similar to that of the plasma protein binding so that an equilibrium is attained between these binding sites. The plasma/cell ratio is on an average 2 but is subject to large interindividual variations. This ratio is only moderately influenced by the presence of other drugs and anticoagulants in the blood. The consequences of the cell binding of drugs for the analytical result when using plasma or whole blood and the evaluation of blood concentrations of their relation to the therapeutic effect are discussed.

[The correlation between milk flow, vacuum fluctuations and decrease in vacuum in the long milk tube at the claw in different milking machines. An introductory examination (author's transl)]

Four different milking machines have been examined for vacuum fluctuations and vacuum decrease in the long milk tube at the claw. Measurements were performed in 3 cows milked with Alfa-Laval high line HP 100, 11 cows in 3 herds milked with Alfa-Laval high line Duovac 300, 5 cows milked with Erland low line milking equipment, and in 3 cows milked with Strangko high line milking equipment. The recordings were done in the cowhouse during the daily dairy management. The milk flow for each cow was measured 24 hrs after the vacuum recordings using Milko-Scope. Compared to the other 3 milking machines, Duovac 300 had a significant higher increase in vacuum fluctuations and vacuum decrease with the increase in milk flow. Just small differences existed between Alfa-Laval HP 100 and Strangko milk pipe line equipments. Smaller vacuum fluctuations and vacuum decrease were recorded in the low line milking equipments compared to the other types. The difference was significant (P = less than 0.001). Significant correlations between milk flow and decrease in vacuum, and between milk flow and vacuum fluctuations were not found for the low line milking machine examined.

False positive reaction for carboxyhemoglobin in blood from liver tissue

On spectrophotometric determination of carboxyhemoglobin in blood collected from the liver of three bodies at three days post-mortem, false positive results were found (5--15 per cent saturation), since samples of heart blood collected a few hours after death did not contain carboxyhemoglobin.

Development and validation of a specific radioimmunoassay for somatostatin in human plasma

Little is known about the factors controlling somatostatin secretion in man, and data are not available on the changes in circulating levels in various human physiological or pathophysiological states. This is mainly a consequence of the technical difficulties involved in measuring somatostatin in plasma. In the presence of plasma, binding of somatostatin tracer to antibody was consistently decreased by about 20%, and this could not be abolished by the addition of EDTA and aprotinin or by the use of specially prepared somatostatin-free plasma. Furthermore, in the presence of plasma, endogenous somatostatin does not dilute in parallel with synthetic cyclic somatostatin standard. We have, therefore, developed and validated a radioimmunoassay for somatostatin using prior extraction of the peptide onto leached silica glass. Tyrosine-II somatostatin was iodinated using lactoperoxidase and purified on ODS silica. This method is superior to iodination using chloramine-T with CMC cellulose purification, and gives a highly purified preparation with a shelf-life of at least eight weeks. Using this tracer and a specific antiserum, the limit of sensitivity of the assay was 10 pg/ml, with an intra-assay coefficient of variation of 12% (n = 16) and inter-assay coefficient of variation of 15% (n - 10). Parallelism has been demonstrated between standard synthetic cyclic somatostatin and all extracted plasma samples. The mean recovery of exogenous somatostatin from plasma was 78%. The fasting level of immunoreactive somatostatin at 0,900 hours in 40 normal subjects ranged from 17 to 81 pg/ml. Care is needed, however, when comparing these values with those obtained from other laboratories since standard preparations of somatostatin vary considerably in their immunopotency.

The effect of somatostatin on epinephrine-induced free fatty acid release in normal man

Epinephrine and saline or cyclic somatostatin were infused into normal persons to study the effect of somatostatin on free fatty acid (FFA) release. Somatostatin had no effect on epinephrine-induced hyperglycaemia. It enhanced basal and epinephrine-induced FFA release, while the release of both immunoreactive insulin (IRI) and immunoreactive glucagon (IRG) was inhibited. We suggest that the rise in FFA levels may be due to either inhibition of IRI or another effect of somatostatin on fatty acid metabolism.

Isolation and anaylsis of (Gp)nXp sequences of rat liver 5S RNA by means of restricted ribonucleas T2 hydrolysis

Essentual difficulties arise when base number in oligoguanylic blocks and location of these blocks along the polynucleotide chain need to be determined in the course of determination of the nucleotide sequences in ribonucleic acids. To overcome this difficulty it is suggested to take advantage of a recently discovered resistance of phosphodiester bond between kethoxalated G and its 3'-neighbour against T(2) RNase hydrolysis 1,2. The approach is illustrated by analysis of 5S RNA from rat liver. Sequences of general formula (Gp)(n)Xp were isolated from T(2) RNase hydrolysate of 5 S RNA rapidly and quantitatively. The information obtained greatly facilitates the whole procedure of sequencing. It is expected that the method proposed would be effective for analysis of 5 S and 4 S RNA and for highmolecular weight fragments of ribosomal and viral RNAs.