Seroepidemiological studies of bovine babesiosis caused by Babesia ovata, B. bigemina and B. bovis in Peninsular Malaysia

Cattle in Peninsular Malaysia were examined for evidence of infection with Babesia ovata, B. bigemina and B. bovis by an enzyme-linked immunosorbent assay for detection of antibody to the three Babesia species. All of the test samples when assayed with B. ovata antigen, resulted in low value indicating low probability of cattle infected with B. bigemina, 74.4% were positive for B. bovis and 72.6% were positive for both Babesia species. In addition, a serological survey with regard to age difference was carried out on a milk production farm. High reactivity antibody to B. bigemina and B. bovis was detected in calves less than 1 month of the age. The reactivity decreased in calves 1-3 months of the age. Then, the reactivity increased for both Babesia species in 6 months old calves. These results suggested that cattle infected with B. bigemina and B. bovis were widespread throughout Peninsular Malaysia and that both parasites might exist as an enzootical parasite.

Improvement of glucose tolerance by bezafibrate in non-obese patients with hyperlipidemia and impaired glucose tolerance

Glucose intolerance or diabetes mellitus, hyperlipidemia, obesity and hypertension may have a close interrelation based on insulin resistance. We selected 28 impaired glucose tolerance (IGT) patients with hyperlipidemia. The IGT patients demonstrated hypertriglyceridemia associated with hyperinsulinemia, a typical manifestation of insulin resistance. Administration of bezafibrate at 400 mg/day for 4 weeks to the IGT patients with hypertriglyceridemia resulted in an improvement of the plasma glucose level and insulin response to 75 g oral glucose loading associated with a concomitant decrease in non-esterified fatty acids. The ratio of the level of serum C-peptide to that of insulin after a 75 g oral glucose tolerance test (OGTT) was augmented after 4 weeks of bezafibrate administration. However, reduction of the cholesterol level with pravastatin did not alter these parameters. These results suggest that treatment to reduce the level of serum triglycerides, but not that of cholesterol, may have a beneficial effect for improving insulin resistance even in the non-obese subjects with IGT and decreasing the risk of coronary heart disease.

Uptake of remnant like particles (RLP) in diabetic patients from mouse peritoneal macrophages

To investigate whether the remnant like particles (RLP), separated from serum by an immunoaffinity gel mixture of anti-apo B-100 and apo A-I monoclonal antibodies, are relevant to the initiation or progression of atherosclerosis, the incorporation of RLP into mouse macrophages was studied using histochemical and biochemical techniques. Remnant lipoproteins such as RLP are reported to contain a large quantity of chyloniron and very low density lipoprotein (VLDL) remnants, especially in diabetic patients. The RLP separated from the sera of 32 diabetic patients were found to be predominantly taken up into macrophages harvested from mouse abdominal cavities by the staining method applying oil red O. Furthermore, using 14C-oleate to prove the uptake of lipoproteins by macrophages, the uptake of RLP-VLDL, a VLDL fraction of RLP by ultracentrifugation, was the next highest to that of the oxidized LDL, which suggests that RLP-VLDL is also aggressively taken up by macrophages. The degree of uptake of RLP-VLDL by macrophages was positively correlated with HbA1c of these diabetic patients (r = 0.556, p < 0.01), irrespective of the ways of the treatment of diabetes. In conclusion, RLP can contribute to the foaming of macrophages, which in turn may explain the acceleration of atherosclerosis in diabetic patients.

The role of insulin in coronary atherosclerosis

In 197 patients with coronary artery disease (CAD) who underwent coronary angiography, 75 g oral glucose tolerance test (OGTT) was performed, measuring plasma glucose(PG) and plasma insulin (IRI) at 4 time points (0, 30, 60 and 120 min). Subjects were separated into two groups by their insulinogenic index (I.I. = delta IRI/delta PG from 0 up to 30 min), 99 cases with good insulin response (I.I. > or = 0.4) and 98 cases with poor insulin response (I.I. < 0.4). Only two subjects were diabetic in good insulin response, while 37 were diabetic in poor insulin response. The severity of coronary atherosclerosis was expressed as a coronary index (CI), calculated according to Balcon's method. Fasting PG and the sum of PG were significantly higher in the latter group, while the sum of IRI was significantly lower. CI was not significantly different, however. In the group with good insulin response, the severity of CAD was significantly correlated to fasting IRI (n = 99, r = -0.387, P < 0.02), but, there was no such relationship in the other group. We conclude that hyperinsulinemia might be a risk factor for ischemic heart disease, but in diabetics it is difficult to link the relationship between fasting IRI and CI.

The relationship between early diabetic nephropathy and control of plasma glucose in non-insulin-dependent diabetes mellitus. The effect of glycemic control on the development and progression of diabetic nephropathy in an 8-year follow-up study

To clarify the relationship between early diabetic nephropathy and the glycemic control in non-insulin-dependent diabetes mellitus (NIDDM) without hypertension, excretion of urinary albumin was studied retrospectively for 8 years. The patients with early diabetic nephropathy were divided into two groups according to the initial urinary albumin index (UAI: mg/g.creatinine), namely, a normoalbuminuric (less than 15 mg/g.creatinine) and a microalbuminuric group (15 < or = UAI < 200 mg/g.creatinine). Comparisons of changes in UAI were made between good (HbA1 < 9.0% and fasting plasma glucose (FPG) < 140 mg/100 mL throughout the observation period) and poor glycemic control groups after 4 and 8 years. In the patients with normoalbuminuria at the initial determination, five of 11 patients (45.5%) with good glycemic control and 14 of 22 patients (63.6%) with poor glycemic control became microalbuminuric after 8 years, respectively (p < 0.05). In the microalbuminuric patients, five of ten patients (50%) with poor glycemic control became macroalbuminuric (UAI > or = 200 mg/g.creatinine), although only one case worsened of five patients with good glycemic control (p < 0.05). In conclusion, the development or progression of early diabetic nephropathy in NIDDM was significantly inhibited by good glycemic control (FPG < 140 mg/100 mL and HbA1 < 9.0%), independent of hypertension, and probably irrespective of the mode of therapeutic intervention.

Genistein augments cyclic adenosine 3'5'-monophosphate(cAMP) accumulation and insulin release in MIN6 cells

Effects of genistein on insulin release were studied using MIN6 cells, a glucose-sensitive insulinoma cell line. At the non-stimulatory concentrations of glucose, genistein did not affect insulin release, however, at the stimulatory concentrations of glucose, genistein significantly increased insulin release in a dose-dependent manner up to 20 micrograms/ml. The content of cAMP in MIN6 cells was also elevated significantly by genistein and the dose-response relationship between the genistein and cAMP accumulation was consistent with the relationship between the genistein and insulin release. These effects were inhibited by calcium antagonists or by the omission of extracellular calcium. Isobutylmethylxanthine (IBMX;0.1mM) increased both cAMP accumulation and insulin release in MIN6 cells and there were no additive effects by the addition of genistein. The accumulation of cAMP might have, at least in part, resulted from phosphodiesterase inhibition by genistein. These results suggest that genistein augments glucose-induced insulin release by the contribution of cAMP accumulation and calcium modulation which depends on extracellular calcium.

Theileria sergenti: transformation of zygotes into kinetes in vector ticks, Haemaphysalis (Kaiseriana) longicornis and H. (K.) mageshimaensis

Invagination or transformation of a zygote of Theileria sergenti into a kinete was examined with Giemsa-stained smears of the midgut of vector ticks, Haemaphysalis longicornis and H. mageshimaensis. Zygotes invaginated almost simultaneously with the moulting of host ticks. They were round and oval, and measured 5.4 to 6.7 microns in diameter on average. The kinetes developing in the zygotes were situated in the periphery of cytoplasm and were spindle- or club-shaped.

Antigen profiles of Anaplasma ovis and A. mesaeterum and cross infection trials with them and A. marginale

Antigen profiles of Anaplasma ovis and A. mesaeterum were analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting, and cross infection trials were performed by A. ovis challenge to A. mesaeterum- or A. marginale-inoculated goats and A. marginale challenge to an A. ovis-inoculated calf. Antigen analysis showed unique and common proteins of A. ovis and A. mesaeterum and identified a major 38 kDa protein to be a dominant immunogen bearing two epitopes common to Anaplasma species. An epitope specific to A. ovis and A. marginale, absent from A. mesaeterum, was recognised on the major protein of A. ovis. Pre-inoculation of goats with A. mesaeterum induced continuous antibody response with low parasitemia and partial protection against A. ovis challenge, as demonstrated by lower peak parasitemia and normal body temperature compared with values for goats inoculated with A. ovis alone. Pre-inoculation of goats with A. marginale and a calf with A. ovis induced weak or no antibody response without parasitemia, and was of no effect for preventing anaplasmosis by heterologous challenge. These results suggest that the development of parasitemia is essential for inducing continuous antibody by which cross protection would be possible.

Protein analysis of Strongyloides venezuelensis by two-dimensional polyacrylamide gel electrophoresis

Infective larvae, larvae in the lung and adult-stage worms in the small intestine of Strongyloides venezuelensis were analysed for protein by two-dimensional gel electrophoresis. The infective larvae were differentiated from the other two stages of parasite with 13 stage-specific spots, whereas the larvae in the lung and the adult-stage worms were identical to each other in spot patterns except for 6 spots.

Histological observations on the schizonts in cattle infected with Japanese Theileria sergenti

Histological observations were performed on the schizonts of Japanese Theileria sergenti in three calves necropsied 8 and 10 days after application of nymphal Haemaphysalis longicornis infected with T. sergenti. In all the three calves, schizonts were observed in the cytoplasm of huge cells formed in the drainage lymph nodes, liver and spleen. The huge cells were 50 to 200 microns in diameter. Schizonts had granular appearance and an irregular shape and were 1 to 7 microns in diameter. Ultrastructurally, schizonts had more than one nuclei and were formed in the unit enlarged cell. Schizonts showed a specific reaction against anti-T. sergenti anti serum, therefore, it was concluded that the schizonts were those of T. sergenti histologically.

Appearance of a regenerating (reg) gene protein in pancreatic islets of remission BB/Wor//Tky rats

Remission of diabetes, i.e. significant amelioration from absolute insulin-dependency, has been sometimes observed in diabetic BB/Wor//Tky rats which were treated with insulin. In remission BB/Wor//Tky rats, plasma glucose levels improved to near normal level and insulin content was also preserved as much as that between diabetic and non-diabetic rats. In this process, we hypothesized that autoimmune insulitis was suppressed and remaining islet B-cells was restored from severe destruction by recovering in number and/or function. While, recently, a novel regenerating (reg) gene, identified in the regenerating pancreatic islets of surgical models, is reported to be related to the replication of pancreatic B-cells in vitro. Based on these findings, we histologically investigated whether the reg protein could be actually expressed or not in the islets from remission BB/Wor//Tky rats. As expected, reg protein was observed in the islets from remission BB/Wor//Tky rats mainly in accordance with pancreatic B-cells. Thus, the present findings suggested that the regeneration of pancreatic B-cells represented by the expression of reg protein might be, at least in part, relevant to remission induced by insulin therapy in spontaneously occurring Type 1 diabetes in BB/Wor//Tky rats.

[Do blood glucose levels in the elderly have different metabolic significance than in non-elderly subjects?]

Diagnostic criteria of diabetes mellitus in elderly people are still controversial. The major questions are whether (1) effects of hyperglycemia in generating diabetic complications are the same as in younger diabetics, (2) too many diabetics might be diagnosed in the elderly by the criteria proposed by WHO and Japan Diabetes Society. To answer these questions, we carried out two studies. Blood glucose data were collected from population-based studies and from voluntary health check-up studies. Fasting blood glucose values were classified by sex and the age (-49, 50-64, 65-years old). Population-based studies showed no age-dependent change in blood glucose. However, data from health check-up studies showed an increase in median values from the group aged 50-64 and the 65 and older group. Two-hour values after glucose tolerance tests were classified by age and the fasting blood glucose (-99, 100-119, 120-139, and 140- mg/dl). The eldest and 140- mg/dl group showed the highest 2-hour values. Effects of hyperglycemia on the appearance of diabetic complications were studied in patients being follow-up in three diabetes clinics. Patients who has a history of one year or less and without any retinopathy on the first visit to the clinic were registered. Data were analyzed by the Kaplan-Meier method and the appearance of retinopathy was used as the end point. There were no difference in the rate of appearance of retinopathy between the age groups (-49, 50-64 and 65-years old). No age effect on the hyperglycemia-dependent appearance of retinopathy could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoprotein E metabolism in sciatic nerves of diabetic rats. Implication for diabetic neuropathy

Apolipoprotein (apo) E secreted by macrophages plays an important role in nerve injury and repair. We investigated the disturbance of neural apo E metabolism in diabetic rats and its relation to diabetic neuropathy. In BB/W rats, genetically diabetes prone rats, the secretion of apo E from sciatic nerves was 3-fold greater than that in control rats. Furthermore, a similar enhancement of apo E secretion was observed in injured nerves of STZ-induced diabetic rats (2-fold) as compared with those of nondiabetic rats, and this was reversible with insulin treatment. Histological examination of the nerves revealed more extensive infiltration of mononuclear cells in the injured nerves of STZ-induced diabetic rats than in those of non-diabetic rats. This is consistent with the findings that chemotactic activities for mononuclear cells, which were released from injured nerves, were greater in the STZ-induced diabetic rats than in the non-diabetic rats. From these results we conclude that the recruitment of monocyte/macrophages into injured nerves is enhanced in diabetes, thereby causing derangement of neural apo E metabolism. These abnormalities might contribute to the development of diabetic neuropathy.

Analysis of the genes encoding immunodominant piroplasm surface proteins of Theileria sergenti and Theileria buffeli by nucleotide sequencing and polymerase chain reaction

The nucleotide sequences of the cDNAs encoding a 33-kDa piroplasm protein of Theileria sergenti (p33) and a similar protein of Theileria buffeli (p34) were determined. Both of the genes contained an open reading frame of 849 base pairs. The predicted amino acid sequence of p33 and p34, consisting of 283 residues, showed 82% similarity. A transmembrane hydrophobic domain and signal peptides were predicted. The polymerase chain reaction was used to amplify p33/34 genes from the piroplasm DNA of T. sergenti, T. buffeli and Theileria orientalis. Following amplification, p33 and p34 genes were clearly differentiated using the restriction enzymes sites that were not shared between them. These results indicated that p33 and p34 were conserved molecules among these Theileria species, and the genes that encode p33/34 proteins were suitable for discrimination of T. sergenti from T. buffeli/T. orientalis.

Preliminary biochemical characterization of 'veil' structure purified from Theileria sergenti-, T. buffeli- and T. orientalis-infected bovine erythrocytes

A structure called 'veil' in Theileria sergenti-, T. buffeli- or T. orientalis-infected bovine erythrocytes was purified from erythrocyte lysates by Percoll density-gradient centrifugation. On electron microscopical examination, the veils consisted of electron-dense material showing a periodicity of striations and were not surrounded by membranes. Analyses of veil proteins by one- and two-dimensional polyacrylamide gel electrophoresis revealed that the veils contain haemoglobin and several other basic proteins of molecular weight ranging from 15.5 to 46 kDa. By comparing the protein patterns of the veil with those of purified piroplasms and uninfected bovine erythrocytes, these basic proteins appeared to be of parasite origin. It would appear likely that the veils formed by intra-erythrocytic precipitation of haemoglobin and proteins excreted by the parasites. Differences in veil constituents were found between T. sergenti, T. buffeli and T. orientalis.

Molecular cloning and immunological analysis of immunodominant piroplasm surface proteins of Theileria sergenti and T. buffeli

cDNA libraries of Theileria sergenti and T. buffeli piroplasms were constructed in lambda gt11 and screened with rabbit anti-piroplasm sera. A major antigen of T. sergenti (33 kDa) and that of T. buffeli (34 kDa) was identified from the recombinant phages by using recombinant antigen-selected monospecific antibodies. The reactivities of the cloned proteins with rabbit antisera, infected calf sera and mouse monoclonal antibody suggested that the 33 and 34 kDa proteins expressed species-common and species-specific epitopes. The DNA probes from these recombinant clones showed species-specific hybridizations in Southern blotting with genomic DNA from piroplasms. These results indicate that the Japanese T. sergenti can be distinguishable from the Australian T. buffeli with regard to a polymorphism of the major immunodominant proteins of piroplasm.

Antigenic differences between Japanese Theileria sergenti and other benign Theileria species of cattle from Australia (T. buffeli) and Britain (T. orientalis)

Serological comparisons among piroplasm antigens of the benign Theileria species of cattle from Japan, Australia and Britain, which are frequently referred to as T. sergenti, T. buffeli and T. orientalis, were carried out. The results obtained from comparative enzyme-liked immunosorbent assay (ELISA) using sera from infected cattle suggest that T. sergenti could be differentiated from both T. buffeli and T. orientalis by their serological dissimilarities. Western blotting combined with two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) revealed that both the 33-kDa piroplasm protein of T. sergenti and the similar 34-kDa protein of T. buffeli and T. orientalis corresponded to immuno-dominant antigens against cattle. The other 32-kDa proteins of . T. buffeli and T. orientalis also represented immunodominant antigens. Cross-reactivities of the 32-and 34-kDa proteins were observed between T. buffeli and T. orientalis, whereas the 33-kDa protein of T. sergenti could be differentiated from the similar 34-kDa proteins of T. buffeli/orientalis. The present study suggests that T. sergenti should be separated from T. buffeli and T. orientalis on the basis of their serological dissimilarities.

A new animal model of non-insulin-dependent diabetes mellitus induced by the NDK25 variant of encephalomyocarditis virus

Intraperitoneal inoculation with NDK25, a variant of Encephalomyocarditis (EMC) virus which has been newly cloned from the M variant of EMC virus (EMC-M), caused DBA/2 mice to develop noninsulin-dependent diabetes mellitus. The NDK25-infected mice demonstrated abnormal glucose tolerance from 1 to 3 weeks after inoculation. The infection resulted in mild insulitis and the destruction of pancreatic beta cells at 1 week after inoculation and led to a significant reduction in the insulin content of the pancreas, but there was no ketonuria. The insulin content of the pancreas was recovered considerably from 15 +/- 3 at 1 week to 95 +/- 16 micrograms/g pancreas at 12 weeks, although the latter value was still significantly lower than that of the control mice (P < 0.05). Under microscopy, mild and partial infiltration of mononuclear cells was observed in about half the pancreatic islets only 1 week after inoculation, and then disappeared. Thus, we believe we have established a new model of noninsulin-dependent diabetes mellitus using the NDK25 variant of EMC virus.

Disturbance of thyroidal iodine metabolism in BB/W rat

To investigate the thyroid function in Bio-Breeding Worcester (BB/W) rats, we have examined the iodine metabolism, serum TSH and thyroid hormone levels in 8- and 16-week-old BB/W and normal Wistar (W) rats. At 8 weeks of age, serum TSH levels were significantly higher in BB/W rats than in W rats, although there was no difference in the serum levels of free T3 and free T4. Furthermore, the thyroidal radioactive iodine incorporation at 48 h was significantly lower in BB/W rats, suggesting that they might have some defects in iodine organification. At 16 weeks of age, serum TSH levels were also significantly higher in BB/W rats than in W rats. Furthermore, serum TSH levels in 16-week-old BB/W rats were significantly higher than in 8-week-old BB/W rats. The thyroid weight was significantly greater in BB/W rats, probably due to the increased serum TSH. The thyroidal radioactive iodine uptake at 48 h and the iodine content in the thyroid homogenates were significantly lower in BB/W rats. These results suggest that BB/W rats have some defect in iodine metabolism resulting in impaired thyroid hormone synthesis.