Characteristic transfer of colostrum-derived biologically active substances into cerebrospinal fluid via blood in natural suckling neonatal pigs.

The characteristic transfer of colostral components into cerebrospinal fluid (CSF) via serum after natural suckling has been studied by sodium dodecyl sulphate (SDS) electrophoresis, two-dimensional electrophoresis, immunoblot and enzyme linked immunosorbent assay methods in non-suckling pigs. Total protein concentrations in the serum increased immediately after first suckling, reached a peak value at 12 h, corresponding to a 2.3-fold compared with pre-suckling level. The protein concentration in CSF also increased and reached peak value at 6 h corresponding to 1.6-fold compared with presuckling level. IgG in serum not detected before suckling, increased steeply after suckling, IgG, IgM and IgA transported into the serum were observed in completely intact form by immunoblot method. The IgG transported into serum was quickly transferred into CSF after natural suckling in contrast to the case of bovine IgG. Serum concentration of transferrin was maintained at high level before suckling and was not changed by suckling. Transferrin also detected in CSF was not changed by suckling. Bovine lactoferrin (Lf) administered into the intestinal lumen was transported into serum (0.01%) and also detected in CSF after 6 h as undegraded form (3.1%). Thus, homologous IgG and bovine Lf are transported into CSF, suggesting that the transport of macromolecules into CSF is selective in neonatal pigs.

Natural Hybridization between Diploid Crucian Carp Species and Genetic Independence of Triploid Crucian Carp Elucidated by DNA Markers.

The population structure of genus Carassius in Lake Koyama, southeast Japan, was analyzed by genetic markers as microsatellite DNA, mtDNA RFLP and isozymes. Based on the ploidy level and morphological analysis, four Carassius groups were detected. The triploid group was identified as Ginbuna (C. langsdorfii). In the diploid group, Nagabuna (C. burugeri sp) and Gengoroubuna, (C. cuvieri) were identified. Remaining diploid individuals had morphological traits that were intermediate between Nagabuna and Gengoroubuna. These were considered as hybrids and their descendants. From the results of mtDNA RFLP and isozyme patterns, the triploid population was considered to be independent from the gene pools of diploid. The hybrids had the mtDNA haplotypes which were common to Gengoroubuna and Nagabuna populations. Based on the three microsatellite loci, Ginbuna was classified into six clonal lines. In the diploid population, substitution of the major alleles of Nagabuna and Gengoroubuna were found. The hybrids had alleles that were common in Nagabuna and Gengoroubuna. The values of the hybrid index (IH) which are ranged from 0.771 to 0.964 in Nagabuna, from 0.102 to 0.806 in the hybrids and from 0.068 to 0.157 in Gengoroubuna. The hybrid population was verified to be derived from crossbreeding between the Gengoroubuna and Nagabuna populations. Evidence of backcrossing in nature by microsatellite DNA markers was also obtained in the diploid populations.

Characteristic transfer of colostral components into cerebrospinal fluid via serum in neonatal pigs.

In order to evaluate the possibility of modification of brain function by colostral suckling, the characteristic transfer of colostral components into serum and cerebrospinal fluid (CSF) has been studied by SDS electrophoresis, immunoblot and ELISA methods in nonsuckling pigs. Total protein concentrations in the serum increased immediately after oral administration of bovine colostrum, reaching a peak value (7.0 +/- 0.7 g/dl) at 24 h after administration, corresponding to a 3-fold increase compared to preinfusion levels. IgG and other macromolecular components (MW 19, 000-58,000) were recognized in serum by electrophoretic and ELISA analysis. Total protein concentrations in the CSF collected from the cisterna magna also increased steeply after colostral administration, reaching a maximal value (54.1 +/- 5.0 mg/dl) at 4 h, corresponding to a 4-fold increase compared to preinfusion levels. Two colostral components (MW 19,000 and 31,000) in serum were confirmed to be present in the CSF by electrophoresis. The component of MW 19,000 was identified by immunoblot as beta-lactoglobulin. IgG in serum transferred from colostrum could not be detected in the CSF by ELISA. Lactoferrin administered into the intestine was also detected in the CSF via serum. These results indicate that some components of colostrum can be transported into the CSF via the serum, suggesting the possibility of modification of immature brain functions by colostral suckling in neonatal pigs.

Characteristic transport of lactoferrin from the intestinal lumen into the bile via the blood in piglets.

Lactoferrin is a major iron-binding protein in milk from several species, such as humans, monkeys, mice and sows. Using neonatal and weaner piglets, the characteristic transfer of lactoferrin from intestinal lumen into bile via the circulation was investigated. Bovine lactoferrin (1 or 3 g/kg body weight) was infused into the stomach through a polyethylene tube or into the duodenum through a duodenal catheter over 5 min. Peripheral blood and bile samples were collected after the infusion. Lactoferrin absorbed into plasma and bile were assayed quantitatively by double-antibody enzyme-linked immunosorbent assay, and homogeneity of bovine lactoferrin in plasma and bile was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting methods. Morphological investigation was carried out according to the peroxidase anti-peroxidase method. Following oral administration in neonatal pigs, bovine lactoferrin appeared in the blood circulation and reached a peak level after 2 h. It was confirmed immunohistochemically that lactoferrin was transported by endocytosis via the epithelial cells. Lactoferrin absorbed into the blood was also detected in the bile and reached a peak value 12 h after oral administration. Transportation of lactoferrin from the intestinal lumen into the bile via the bloodstream was also observed in weaner piglets. Lactoferrin transported into plasma and bile was confirmed to be the same substance as administrated lactoferrin by electrophoresis and immunoblotting methods. Lactoferrin transported into bile was re-absorbed into the blood in neonatal pigs. These results demonstrate that lactoferrin contained in milk is transported into the circulation from the intestinal lumen and excreted into the bile, suggesting the possibility of entero-hepatic circulation of lactoferrin in neonatal pigs.

Analysis of the electroencephalogram in growing calves by use of power spectrum and cross correlation.

OBJECTIVE: To determine postnatal maturation of findings in the electroencephalogram (EEG) of calves and estimate the degree of electrophysiologic activity, using power spectrum and cross-correlation analyses of the EEG. ANIMALS: 10 clinically normal Japanese Black calves ranging in age from 1 to 10 weeks. PROCEDURE: EEG were recorded at various stages of consciousness. Power spectrum and cross-correlation analyses were applied to a relaxed state EEG. RESULTS: After the second week of age, rhythmic waves with frequencies of 6 to 9 Hz (alpha rhythm-like pattern) appeared in the EEG during the relaxed state, and were recorded in the occipital and vertex areas; duration of appearance was < 30 seconds. By use of power spectrum analysis, power distribution of the 7.5- to 10-Hz frequency band in the occipital area significantly increased after the sixth week. The highest frequency (18 to 30 Hz) band increased in the frontal and occipital areas after the seventh week. Normalized cross-correlation coefficients at 0 time shift were > 0.6 throughout the experimental period. The normalized cross-correlation coefficients obtained from caudal interhemispheric sites increased after the second week, and were significantly greater than those in rostral sites. CONCLUSIONS AND CLINICAL RELEVANCE: Developmental changes in the EEG of calves during the first 10 weeks could be characterized by appearance of the alpha rhythm-like pattern and increase of the power distributions of the 7.5- to 10-Hz and 18- to 30-Hz frequency bands, which might be a useful indicator for estimating brain activity in young calves and as standard data for evaluating abnormal brain activity in calves.

Postnatal development of EEG patterns, catecholamine contents and myelination, and effect of hyperthyroidism in Suncus brain.

The postnatal development of the central nervous system (CNS) in house musk shrew in the early stage of maturation was studied. The electroencephalogram (EEG) and visual evoked potential (VEP) in association with catecholamine contents and myelin basic protein (MBP) immunoreactivity were carried out from the 1st to the 20th day of postnatal age. Different EEG patterns which were specific to behavioral states (awake and drowsy) were first recorded on the 5th day, and the total power which was obtained by power spectrum analysis increased after this stage. The latencies of all peaks in VEP markedly shortened between the 5th and the 7th day. Noradrenalin (NA) content of the brain showed a slight increase after the 3rd day, and reached maximum levels on the 7th day, which was delayed a few days compared to dopamine (DA). In hyperthyroidism, the peak latency of VEP was shortened and biosynthesis of NA in cerebral cortex and DA in hippocampus was accelerated. The most obvious change in MBP-immunoreactivity of the telencephalon occurred from the 7th to the 10th day. These morphological changes in the brain advanced at the identical time-course to those in the electrophysiological development and increment of DA and NA contents.

[The EEG pattern in the growing Japanese black calves].

Developmental EEG examination was performed in ten Japanese Black calves aged from 1 week to 10 weeks. The EEG was markedly influenced by the level of consciousness. In the alert wakefulness, the EEG was high frequency, low voltage pattern. In the wakefulness, the dominant activity was low frequency, and low voltage, high frequency activity was superimposed. In the drowsiness, the EEG was high voltage, low frequency activity pattern. In the sleep, markedly high voltage, low frequency activity was dominant. These four EEG patterns observed from the 1st week to the 10th week. During the course of the examination, high frequency, low voltage activity increased, so the EEG pattern gradually developed to the 10th week of age. In the wakefulness, theta wave and alpha wave dominant pattern was observed in seven calves. This pattern was observed after the 2nd week of age, thereafter incidence of this pattern increased to the 5th or 6th week. The frequency of theta wave and alpha wave dominant pattern increased from 6.0-7.5 Hz at the 3rd week to 7.5-9.0 Hz at the 10th week. As described above, the development of the central nervous system has attained the considerable level in the newborn calves, and thereafter continue to develop.

[Visual evoked potentials (VEPs) by leadings on scalp and dura in rabbits].

Visual evoked potentials (VEPs) were obtained from five rabbits. Responses to the photic stimulation were recorded by leading on scalp and dura. Stimulating conditions were changed in order of binocular, monocular (left and right) and screened binocular. The VEP waveforms leading on scalp and dura were composed of five positive and four negative peaks. The amplitude of the VEP leading on dura was about five times larger than that of the VEP leading on scalp. The VEP evoked by the monocular stimulation was characterized by the decreased amplitude in the ipsilateral hemisphere to the stimulated eye. It is furthermore characteristic in the dural recording that the major negative peaks in the early component disappeared in the same side as the stimulated eye. These differences in the VEP evoked by the monocular stimulation might reflect that the most projection of optic nerve cross at the optic chiasm in rabbits.

Postnatal development of visual evoked potentials in Japanese black calves.

The visual evoked potential (VEP) was recorded in six Japanese Black calves from 1 to 10 weeks after birth. The VEP waveform recorded at the 1st week was consisted of three positive and three negative peaks. The VEP showed little postnatal changes except for the shortening of the peak latencies of P1 and N3 and the increase of the peak-to-peak amplitudes of P1-N1 and P2-N2 (significant between the 1st and 10th week of age). The visual function associated with generation of the flash VEP is suggested to have almost developed at birth in the calf. The postnatal measurement of the VEP would be useful for evaluating the neurologic disorders of the visual system in young calves.

Visual evoked potentials in guinea pigs with brain lesion.

Visual evoked potentials (VEPs) were recorded in 10 adult male guinea pigs with brain lesion. Lesions were produced in 5 animals by superficial suction of the occipital lobe. The other 5 animals were orally administered with hexachlorophene (about 35 mg/kg/day) for 28 days. In the VEP following the ablation of the occipital lobe, the peaks P10, N20, P55, N75, N140 and P200 disappeared in many cases. The amplitude of the peak N40 decreased to approximately one half its control VEP. In the VEP obtained from the animals administered with hexachlorophene, the peak latencies of N20, P30, P55, N75 and P100 were slightly prolonged after the 7th day following the first administration. On the other hand, there was no change in the latency of N40 during the whole period of administration. The peak-to-peak amplitude showed some variability in different peaks. Histologically, diffuse status spongiosis were found in the white matter of the cerebrum, cerebellum, and brain stem. As described above, the ablation of the occipital lobe caused markedly depressed VEPs, however, the responses to the photic stimulation persisted after the injury. On the other hand, the VEPs of animals administered with hexachlorophene showed a high probability of peak appearance, and a decrease in amplitude was not marked.

Changes in the visual evoked potentials with different photic conditions in guinea pigs.

Visual evoked potential (VEP) was studied in five adult male guinea pigs weighing 350-750 g. VEPs were recorded with chronically implanted electrodes. Photic stimulation was presented in the following order: binocular, left eye, right eye, and screened binocular. The averages of the responses were made from 140 samples. When a single eye was exposed to photic stimulation, the ipsilateral VEP was different from the contralateral VEP; the peaks N140 and P200 disappeared, and the peak latencies of N75 and P100 were significantly (P less than 0.05) longer than those in the contralateral hemisphere. Peak-to-peak amplitude N40-P55 in the ipsilateral VEP was significantly (P less than 0.05) lower than that in the contralateral VEP. The contralateral VEP by monocular stimulation was generally indistinguishable from the response to binocular stimulation. As described above, when only a single eye was exposed to flashes, the ipsilateral dural VEP was different from the contralateral dural VEP.

Visual evoked potential from scalp in guinea pigs.

Visual evoked potentials (VEPs) recorded from the scalp in guinea pigs were compared with those from the dura. The study was performed with ten adult male guinea pigs weighing 350-750 g. VEPs recorded from the scalp had large negative components (N40 and N75) and a large positive component (P55). The waveform of the VEP in the scalp recording was similar to that in the dural recording in that N40 was a major early negative component. Great differences between the scalp and the dural recording were observed in the late negative components (N75 and N140). In the dural recording, the peak N75 was a very small component, and the peak N140 was very large. There was no significant difference between the peak latencies of the two kinds of VEPs except for the peaks P55 and P100. Peak-to-peak amplitudes of VEPs recorded from the scalp were smaller than those from the dura except for P55-N75. The peak-to-peak amplitude in the scalp recording compared to that in the dural recording varied from a ratio as low as 1.0:2.9 to as high as 1.0:36.2, and was markedly variable in each component. The scalp recording correlated with the dural recording as regards the early component.

Electroencephalogram of Japanese Black calves affected with cerebrocortical necrosis.

Electroencephalogram (EEG) examinations were carried out on three Japanese Black calves (1, 2 and 14 week old) affected with cerebrocortical necrosis (CCN) in order to investigate the relationship between EEG abnormalities and encephalic lesions. Some neurologic signs such as circling, astasia, convulsion and opisthotonus appeared in two of the calves (case 1 and 3). The other calf (case 2), however, showed no neurologic signs. The EEGs obtained from the two calves (case 1 and 2), in the awake state, showed constant high amplitude (50-160 microV) and slow (1-4 Hz) activity (HASA). One of these (case 1) had necrosis mainly in the right hemisphere and showed a markedly asymmetric sharp wave. On the other hand, in case 3, the EEG showed diffuse lowered activity, and almost flat in some leads. A decrease in fast activity observed in common with all three animals. These findings suggest that one of the characteristic EEG patterns of CCN patient may be HASA and decreased fast activity. Histopathologic diagnoses of the calves were CCN in various degrees. The degrees of abnormality of the EEGs seemed to accord with the seriousness of the lesions. Because the EEG obtained from the calf having no obvious neurologic signs showed an abnormal pattern, it was considered that EEG examinations in the early stages of disorders are valuable to diagnose CCN.

[Visual evoked potential in guinea pigs].

The present study was designed to establish visual evoked potential (VEP) as one of clinical tests for veterinary medicine. Experiments were carried out on eight adult male guinea pigs weighed 350 to 750 g. We investigated influences of click sound, luminous intensity and habituation on VEP patterns. The VEP of the guinea pig was composed of primary (P 10, N 20, P 30, N 40) and secondary (P 55, N 75, P 100, N 140) components, followed by a rhythmic after-discharge. Click sound with flash produced some unclear peaks in VEP, while click sound without flash elicited clear six peaks. These different components of the response to stimulation suggested that the acoustically evoked potential induced some peaks in VEP. With the intensity used in the present study, changes in luminous intensity resulted in unrecognizable difference among the VEPs. Early components of VEP were not clearly influenced by the habituation to stimulation. As the stimulation was repeated, rhythmic after-discharge seemed to be suppressed in the half of experiments.

[Development of visual evoked potentials in guinea pigs].

The development of visual evoked potential (VEP) was studied in guinea pigs as a function of age. Ten newborn guinea pigs from 3 litters were used, and experiments were carried out with the animals over an age span ranging from 1 to 90 days. Periodic recordings were obtained at 5 day intervals from the first up to the twentieth day after birth and at 30 day intervals from the thirtieth to ninetieth day after birth. The results were as follows: 1) The VEP comprised 7 peaks at the first day after birth, while after the fifth day it was composed of 9 peaks. 2) During the development of the guinea pigs, the latencies of VEP decreased. The reduction of the latencies of peak N2 amounted to about 25% from the first to the thirtieth day. 3) The amplitude of the initial negative spike increased from the first to the fifth day after birth, and decreased after the fifth day.