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The hyperinsulinemic–euglycemic clamp (EGC) technique was used to investigate the effects of calcium salts of long-chain fatty acids (LCFA-Ca) and rumen-protected Met (RPM) on insulin sensitivity in the peripheral tissues of lactating cows. Six multiparous Holstein cows were used in a 3 × 3 Latin square experiment in each 14-d period. Dietary treatments were 0 (RPM0), 20 (RPM20), and 60 (RPM60) g/d of RPM, supplemented with a diet containing 1.5% of LCFA-Ca equal to 110% of the cows' ME requirement. And as a control for the 3 LCFA-Ca–containing diets, a dietary treatment without LCFA-Ca (Con) was also included. After a 10-d adaptation period, milk samples were collected for 4 d, and EGC experiments were performed on d 14 of each treatment period. Insulin solution was infused through a jugular vein catheter at a rate of 0.1, 0.2, 0.3, and 0.4 milliunits·kg BW–1·min–1for 30 min and then at a rate of 0.5 milliunits·kg BW–1·min–1for 60 min. Glucose solution was variably infused to maintain plasma glucose at steady state through the same catheter. Blood samples for measurements were taken using the contralateral catheter. Plasma total cholesterol, cholesterol ester, free cholesterol, and phospholipid concentrations in RPM0 and RPM20 were higher than those in Con, whereas the concentrations in RPM60 were low at the same degree of those in RPM0 (P< 0.05). Plasma Met concentration was greatest in RPM60 (P< 0.05). In the EGC experiment, the glucose infusion rate was greater in RPM60 than in RPM0 and RPM20 and an effective concentration of insulin resulting in 50% maximal glucose infusion rate was lower in RPM60 compared with RPM0 (P< 0.05), indicating that insulin sensitivity was intensified in RPM60. Although the insulin sensitivity evaluated from the EGC data in RPM0, RPM20, and RPM60 was not different from Con, a slight decline was observed in RPM0 and insulin sensitivity in RPM60 was higher than Con. Our results from the EGC experiment demonstrated that the feeding RPM lead to increased insulin sensitivity, which suggests that dietary Met affects lipid metabolism via insulin action in lactating dairy cows fed a LCFA-Ca–containing diet.

The current study was performed to clarify the effects of GHRH treatment on milk production and plasma hormones and metabolites in lactating Japanese Black cows (a beef breed) under negative energy balance (EB). Ten multiparous lactating beef cows were offered a normal-energy diet daily (110% of ME requirements for maintenance and lactation) until 5 d in milk (DIM) to standardize the cows before dietary treatment. From 6 DIM to the final days (63 DIM) of the experiment, the cows were allotted to experimental dietary treatments: 5 cows were offered a diet formulated for 130% [high-energy diet (HED)] and the remaining 5 cows were offered a diet formulated for 80% [low-energy diet (LED)] of ME requirements for maintenance and lactation. In addition, all cows received daily subcutaneous injections of 3 mg of bovine GHRH from 36 to 56 DIM (GHRH treatment period). Differences in BW of HED- and LED-fed cows at 63 DIM were +28.4 and −7.2 kg compared with BW at 6 DIM, and HED- and LED-fed cows were under positive EB (+23.7 MJ/d) and negative EB (−11.6 MJ/d) throughout the experiment period. Treatment with GHRH increased (P< 0.01) the average daily milk yield to 6.2 kg in HED-fed cows compared with a milk yield of 5.3 kg for 7 d before the GHRH treatment period (pretreatment period); LED-fed cows had no increase in milk production from GHRH treatment. Plasma GH, IGF-1, insulin, and glucose concentrations increased (P< 0.05) after GHRH treatment in both HED- and LED-fed cows; GHRH treatment also induced an increase (P< 0.05) in the net area under the curve of plasma insulin after glucose challenge in both HED- and LED-fed cows. Plasma urea N concentrations were decreased (P< 0.05) by GHRH treatment in HED-fed cows, but not in LED-fed cows. Plasma NEFA concentration was unaffected by GHRH treatment in both HED- and LED-fed cows. We conclude that GHRH treatment of lactating Japanese Black cows stimulates endogenous GH and subsequent IGF-1 secretion and might induce an increase in insulin resistance, irrespective of EB; however, compared with lactating dairy cows, both galactopoietic and lipolytic effects of GHRH might be insufficiently exerted under negative EB in lactating beef cows.

Urea is an important reutilizable nitrogen source for the ruminant and is mainly synthesized through the urea cycle in the liver. The cycle is undertaken by 5 enzymes: carbamoyl phosphate synthetase (CPS), ornithine transcarbamoylase (OTC), arginino-succinate synthetase (AS), argininosuccinate lyase (AL), and arginase. The purpose of this study was to investigate changes in the activity of the enzymes and mRNA expression, given that previous observations have indicated an increase in plasma urea concentrations with age in Holstein calves. First, plasma concentrations of metabolites and hormones were determined in calves at 1, 3, 8, 13, and 19 wk of age (n = 4, weaned at 6 wk of age). The plasma concentration of urea drastically increased after weaning (P< 0.001). The plasma concentration of glucose was lowest at 8 wk. The plasma concentration of IGF-I gradually increased with age, although those of NEFA, glucagon, and cortisol decreased (P< 0.001). Concentrations of triglyceride, α-amino nitrogen, growth hormone, and insulin did not change significantly with age of the calf. Next, using the liver tissues taken from calves at 2, 13, and 19 wk of age (n = 4 to 6 at each time point, weaned at 6 wk of age), we measured the activity and mRNA expression of the enzymes by biochemical methods and quantitative reverse transcription-PCR, respectively. The activities of CPS (P< 0.001), OTC (P= 0.001), and AS (P= 0.015) increased with age, whereas AL (P= 0.003) decreased. Although mRNA expression was decreased with age for AL (P= 0.002) and arginase (P= 0.007), no significant change was observed for CPS, OTC, or AS mRNA expression. We conclude that the increased urea production in the liver may be explained not only by an increase in the activities of the urea cycle enzymes, but also by increased ammonia production by rumen fermentation and gluconeogenesis from amino acids around weaning time.

The current study was conducted to clarify the characteristics of glucose and urea kinetics in male Japanese Black calves, using a glucose and urea dilution method with stable isotopes, at preweaning (3 wk of age) and postweaning (13 and 26 wk of age) stages, in comparison with the kinetics of glucose and urea in male Holstein calves. Six Japanese Black and 6 Holstein calves were arranged in a 2 (breed) × 3 (stage) factorial block design. These 12 suckling calves were fed only whole milk, offered concentrate and or-chardgrass hay after 3 wk of age, and weaned at 6 wk of age. Under steady-state conditions, glucose challenges (1.0 mg/kg of BW; [U-13C]D-glucose) and urea challenges (both 2.2 mg/kg of BW; [13C]urea and [15N2]urea) were performed at the 3 stages examined. There were no significant differences in plasma glucose concentrations between Japanese Black and Holstein calves at any stage, but the glucose concentrations at 3 wk of age were greater (P<0.05) than those at 13 wk of age in both breeds. The glucose pool size in Japanese Black calves was smaller (P<0.05) than that in Holstein calves at all stages. Within each breed, there were no significant differences between the glucose pool sizes at 3 and 13 wk of age, but the glucose pool size was larger (P<0.05) at 26 wk of age. Moreover, Japanese Black calves had greater glucose irreversible loss rates (P<0.01) than Holstein calves at 3 wk of age, and the glucose irreversible loss rates were less (P<0.05) on and after 13 wk of age in both breeds. Japanese Black calves had greater plasma urea N concentrations (P<0.05) than Holstein calves at all stages, and in both breeds, the urea N concentrations increased (P<0.05) with age. The urea pool size was smaller (P<0.01) in Japanese Black calves than in Holstein calves at all stages, and in both breeds, the urea pool size increased (P<0.05) with age. In comparison with Holstein calves, Japanese Black calves had greater urea irreversible loss rates (P<0.05) on and after 13 wk of age and greater urea recycling rates (P<0.05) at 26 wk of age. In addition, in both breeds, urea irreversible loss rates and urea recycling rates increased (P<0.05) with age. We conclude that Japanese Black calves have partially different glucose and urea kinetics from Holstein calves and that the kinetics of these metabolites in both Japanese Black and Holstein calves are strongly influenced by weaning.

Endotoxin induces marked changes in lipid metabolism via its effects on cytokines. To evaluate the role of tumor necrosis factor-alpha (TNF) in mediating changes of lipid metabolism in ruminants, we performed a crossover saline-controlled study in Holstein heifers (n = 8; 394.0 kg average BW), investigating the metabolic effects of a single intravenous administration of recombinant bovine TNF (rbTNF, 5.0 μg/kg). Blood samples were taken from a jugular vein at 0 (1100, just before injection), 0.5, 6, 12, and 24 h after each treatment. Dry matter intake in the heifers was not affected by single administration of the rbTNF. The rbTNF produced early as well as later hypertriglyceridemia (P< 0.05) in dairy heifers. The rbTNF also induced an early and sustained rise (P< 0.05) in the plasma NEFA concentration. Plasma retinol concentration was decreased (P< 0.05) at 24 h after rbTNF injection, whereas the α-tocopherol concentration was not significantly affected by rbTNF treatment. At 0.5 and 24 h, there was an increase (P< 0.05) in the plasma concentration of the very-low-density lipoprotein (VLDL) fraction in rbTNF-treated heifers. Between 6 and 24 h after rbTNF treatment, concentration of the low-density lipoprotein fraction declined (P< 0.05) but the high-density lipoprotein fraction was not altered in the rbTNF-treated heifers. These results indicate that TNF produces a hypertriglyceridemic response associated with an increase of the VLDL fraction and a disturbance of retinol metabolism in dairy heifers.

Four experiments were conducted to clarify the effect of intravenous (i.v.) administration of recombinant bovine tumor necrosis factor alpha (rbTNF) on selected metabolites and on hormone secretion in Holstein heifers (n = 6; 347.0 kg average BW). In Exp. 1, rbTNF was injected at three dosage levels in a Latin square; 0 (CONT), 2.5 (TNF2.5), or 5.0 (TNF5) µg/kg BW. Plasma glucose and triglyceride concentrations were at first elevated (P< .05) by rbTNF treatment and then were decreased (P< .05) by TNF2.5 and TNF5. Plasma NEFA concentrations were increased (P< .05) in rbTNF-treated groups. The injection of rbTNF resulted in an increase in plasma insulin levels (P< .05 with TNF5) during the period between 2 and 24 h, except for the period between 6 and 8 h, after the treatment. In Exp. 2, 3, and 4, each heifer received i.v. injections of glucose (.625 mM/kg BW) + rbTNF (5 µg/kg) or glucose + saline (10 mL) (Exp. 2), insulin (0.2 U/kg) + rbTNF or insulin + saline (Exp. 3), and GHRH (0.25 µg/kg) + rbTNF or GHRH + saline (Exp. 4) at 1-wk intervals. In Exp. 2, rbTNF inhibited (P< .05) glucose-stimulated insulin secretion during the initial phase. Thereafter, plasma insulin was higher (P< .01) with the glucose + rbTNF treatment than with the glucose + saline treatment. Treatment with rbTNF inhibited the insulin-stimulated glucose utilization (Exp. 3) and GHRH-stimulated GH secretion (Exp. 4) during the initial phase. These results suggest that rbTNF directly and(or) indirectly affects the intermediary metabolism and hormone secretion in Holstein heifers.

This survey of traumatic spinal cord injuries in Japan from January 1990 to December 1992 was carried out by a statistical method of the nationwide epidemiological study. The number of the registered patients during these 3 years was 9752 and the mean response rate of every of the 47 prefectures was 51.4%. The registered patients with neurological deficits (Frankel A-D) were 7471 and the annual spinal cord injury incidence was 40.2 per million. The ratio of cervical cord injuries to more caudal SCI was 3:1. The age distribution and the causes of spinal cord injuries are presented in detail. From the results of this study, the prevention campaign should be focused mainly on the following topics: sports and motorcycle accidents involving young people; traffic accidents involving adults; falling accidents involving aged people.

Post-mortem microangiography has been performed in 12 patients with traumatic cervical cord injury, 2 patients with myelopathy, and one patient with posttraumatic syringomyelia.Microangiography defined 4 zones in the injured spinal cord.In traumatic injury, the size and extent of the non-filling area (Zone 1) was directly related to the injury force. Subsequently these areas became cavitated. Surrounding the non-filling area, widely extending areas demonstrated filling of capillaries but showed damaged neurons and axons (Zone 2). In the chronic stage, Zone 2 replaced by gliomesenchymal tissue. The capillaries in the gliomesenchymal scars revealed a distorted abnormal arrangement (Zone 3).In a case with myelopathy, the hypervascular areas (Zone 4) were observed just around the chronically compressed area. The vascular increases were considered to be a reaction against chronic compression.In a patient with post-traumatic syringomyelia, the vascular network of the posterior grey matter disappeared and the central arteries were distorted by the distending forces of the syrinx. The microangiographs suggested that vascular factors might play a significant role in original cavity formation; but in cavity extension, these factors were not primary.

This paper presents a method of reducing the interaction effect between the input and output peculiar to the Dynamically Tuned Dry Gyro (TDG), and the possibility of measuring angular accelerations about two axes, through improvements of the Rebalance Control Circuit (RCC) installed on the TDG. First, the use of the TDG as a two-axis rate sensor is shown along with direct and cross transfer functions relating two outputs and two inputs; and it is shown that the TDG makes it possible to simultaneously measure two-axis angular velocities and two-axis angular accelerations if the RCC is improved to facilitate noninteracting control. Next, the design procedure and the results of the trial manufacture on the hardware of each element of the RCC necessary to meet its capability are shown. Third, from the results of the experiments using this manufactured RCC it is clarified that the frequency characteristics of direct transfer functions which prescribe the system performance are hardly influenced by the manufacturing accuracy of the RCC, but the gain chracteristics of cross transfer functions, which correspond to the degree of reduction of the interaction effect, are significantly influenced by the manufacturing accuracy.

To survey the situation of traumatic spinal cord injuries (SCI) in Japan, the SCI Prevention Committee of the Japanese Medical Society of Paraplegia sent out by mail study charts in the form of questionnaires to institutions nationwide. Using the statistical method of the nationwide epidemiological survey described by Hashimoto et al,1the annual estimated incidence was obtained from the number of patients registered, and from the questionnaire reply rate at each prefecture. The number of registered patients in 1990 was 3465 and the mean reply rate was 56.6%. There were 2665 registered patients with a neurological deficit (Frankel A-D) and the annual SCI incidence was 39.4 per million.The male:female ratio was 4.3:1 and the ratio of cervical cord injures to those caudal to the cervical cord was 2.9:1. The mean age at the time of injury was 48.5 years. The cause most frequently seen was traffic accidents, the second most frequent being falls from a height. Besides those two, sports injuries and falls on level ground were the third most frequent causes of SCI in the young generation and in elderly people respectively.

We have studied 29 patients for at least five years after canal-expansive laminoplasty for cervical spondylotic myelopathy. The short- and long-term clinical results were compared, and successive radiographs assessed. The long-term clinical outcome was excellent in five patients, good in 12, fair in 11 and poor in one. The mean short- and long-term improvements were 54.4% and 48.5% but patients with focal kyphotic, kyphotic and S-shaped cervical spines did less well, as did those who had a decrease in the index of curvature of the cervical spine of more than 10 at follow-up. Canal-expansive laminoplasty with reconstitution of the posterior soft tissues may help to prevent postoperative malalignment and late neurological deterioration.