A novel nonsense mutation in exon 1 and a transition in intron 3 of the lipoprotein lipase gene

We examined the lipoprotein lipase (LPL) gene by single strand conformation polymorphism (SSCP) and by restriction fragment length polymorphism (RFLP) analysis in 106 patients with hypertriglyceridemia to screen for novel mutations and to study the contribution of LPL genetic defects in hypertriglyceridemia. We found a single incidence of a homozygous novel nonsense mutation (216G-->A; -14Tryptophan-->stop codon) in exon 1 and 6 cases heterozygous for a single transition (C-->T) at six bp upstream from splicing acceptor site of intron 3. These mutations were not found in 105 normolipidemic controls. The proband homozygous for the nonsense mutation in exon 1, a 74 year old woman, had mild hyperchylomicronemia and her post-heparin plasma showed no LPL protein. However, four heterozygous among family members did not demonstrate hypertriglyceridemia. The frequency of heterozygosity for the C-->T transition in intron 3 was significantly different from that in normolipidemic controls. Therefore, it was suggested that the mutation is involved in hypertriglyceridemia. All of the heterozygotes were men with 4 patients having impaired glucose tolerance or diabetes mellitus. These observations suggest that this polymorphism in intron 3 combined with other as yet undefined factors may be related to hypertriglyceridemia.

Induction of tyrosine phosphorylation and translocation of ezrin by hepatocyte growth factor/scatter factor

Ezrin is a member of the TERM family and is a key protein in cytoplasmic membrane-cytoskeleton interactions. This study showed that hepatocyte growth factor/scatter factor (HGF/SF), a cytokine known to regulate motility, morphogenesis and growth of cells, stimulated the tyrosine phosphorylation of ezrin in a human colon epithelial cell line, HT115. After HGF/SF stimulation, ezrin translocated from the cytosol and generalised membrane to the areas of ruffled membrane as visualised by indirect immunofluorescent and immunogold electron microscopy. This effect was inhibited by genistein, a tyrosine kinase inhibitor. It is concluded that HGF/SF induces ezrin translocation by stimulation of its tyrosine phosphorylation and that this plays a key role in HGF/SF induced membrane ruffling.

Domains with transcriptional regulatory activity within the ALL1 and AF4 proteins involved in acute leukemia

The ALLI gene, located at chromosome band 11q23, is involved in acute leukemia through a series of chromosome translocations and fusion to a variety of genes, most frequently to A4 and AF9. The fused genes encode chimeric proteins proteins. Because the Drosophila homologue of ALL1, trithorax, is a positive regulator of homeotic genes and acts at the level of transcription, it is conceivable that alterations in ALL1 transcriptional activity may underlie its action in malignant transformation. To begin studying this, we examined the All1, AF4, AF9, and AF17 proteins for the presence of potential transcriptional regulatory domains. This was done by fusing regions of the proteins to the yeast GAL4 DNA binding domain and assaying their effect on transcription of a reporter gene. A domain of 55 residues positioned at amino acids 2829-2883 of ALL1 was identified as a very strong activator. Further analysis of this domain by in vitro mutagenesis pointed to a core of hydrophobic and acidic residues as critical for the activity. An ALL1 domain that repressed transcription of the reporter gene coincided with the sequence homologous to a segment of DNA methyltransferase. An AF4 polypeptide containing residues 480-560 showed strong activation potential. The C-terminal segment of AF9 spanning amino acids 478-568 transactivated transcription of the reporter gene in HeLa but not in NIH 3T3 cells. These results suggest that ALL1, AF4, and probably AF9 interact with the transcriptional machinery of the cell.

The effects of recombinant human insulin-like growth factor (rhIGF)-1 and rhIGF-1/IGF binding protein-3 administration on rat osteopenia induced by ovariectomy with concomitant bilateral sciatic neurectomy

We compared the effect of administration of recombinant human insulin-like growth factor-1 (rhIGF-1) alone or the rhIGF-1/IGF binding protein-3 (IGFBP-3) complex on osteopenia in rats. Female Sprague-Dawley rats (8 months old) underwent combined ovariectomy and bilateral sciatic neurectomy (OVX-NX) or sham operation only. After 2 months, the OVX-NX animals were injected subcutaneously with rhIGF-1 alone or with rhIGF-1A IGFBP-3 equimolar complex for 4 weeks. The IGF-1 contents and dose were 0.3 mg/kg of body weight (BW) three times/week, 3 mg/kg of BW once/week, or 3 mg/kg of BW three times /week. At the end of the experiment, the 4th and 5th lumbar vertebrae (L4, L5) and the proximal tibiae were removed after tetracycline labeling, and histomorphometrical analyses were performed on undecalcified sections using Villanueva's staining. The cancellous bone volume at L5 significantly increased by thickening of the trabecular width in rats treated with the complex. However, the increase in the values at the proximal tibia was not significant. The bone formation rates (BFR/BS) in the lumbar vertebrae of rats treated with the complex three times a week at doses of 0.3 mg/kg of BW and 3 mg/kg of BW were both significantly increased but the parameter increase was less marked with the dose of 3 mg/kg of BW once/week. The BFR/BS did not increase significantly in animals treated with IGF-1 alone. These findings clearly demonstrated that the effect of systemically administered rhIGF-1 on bone formation was markedly potentiated when combined with IGFBP-3 in estrogen deficiency combined with reduced activity. The action of IGF-1 was less potent on the bone in paralyzed limbs. The action of rhIGF-1/IGFBP-3 on trabecular bone appeared to depend not only on the dose but also on the frequency of administration and the parts of the skeleton in rats.

Six-membered cyclic phosphonate GABA antagonists, 2,5-disubstituted 1,3,2-dioxaphosphorinanes

The trans isomer of 2-(4-bromophenyl)-5-tert-butyl-2-thiono-1,3,2-dioxaphosphorinane competitively inhibited the specific binding of 35S-tert-butylbicyclophosphorothionate to rat brain membranes with an IC50 value of 0.52 microM, and showed insecticidal activity against houseflies with an LD50 value of 2.4 micrograms/fly. This compound and its analogues acted as noncompetitive GABAA receptor antagonists (NGRAs), and phosphorus-containing cyclohexane skeletons may prove useful for the design of novel NGRAs.

[Burden of dietary therapy on elderly patients with diabetes mellitus]

As a part of a QOL study in elderly diabetes mellitus, we performed an interview conducted by professional interviewers on the sense of burden of dietary therapy in 383 elderly outpatients with diabetes mellitus aged over 60 years old. We used a scale on Burden of Dietary Therapy (BDT) that consisted of 7 questions (calorie restriction, dietary balance, regular dietary habits, restriction of favorite food, restriction of amounts of snacks, restrictions when eating out, burden of total dietary therapy). The sense of burden was rated from 1 (never burdened) to 4 (heavily burdened) for each question and the alpha coefficiency of the BDT scale was 0.80. Women, relatively younger elderly patients, hyperglycemic patients, or tablet-treated patients had higher BDT scale scores. The lower the positive family support scores and the higher the negative social support scores the greater was the BDT score. High BDT scores were significantly associated with low PGC moral scales (p < 0.001). The results suggest that the burden of dietary therapy could lower the quality of life in elderly patients with diabetes mellitus.

A novel factor-dependent human myelodysplastic cell line, MDS92, contains haemopoietic cells of several lineages

A novel long-term cultured interleukin (IL)-3-dependent human myelodysplastic cell line, MDS92, was shown to contain several myeloid-lineage cells such as neutrophils, macrophages, eosinophils, and a small number of megakaryocyte-lineage cells. Therefore this cell line possesses at least bipotential characteristics of myeloid- and megakaryocyte-lineages. Granulocyte colony-stimulating factor clearly promoted the neutrophil alkaline phosphatase activity of MDS92 cells. To the contrary, the incidence and growth of CD41-positive cells were hardly affected by the addition of IL-6, IL-11, c-mpl ligand (thrombopoietin, TPO) or erythropoietin. TPO slightly supported the growth of CD34-positive cell fraction, but not CD41-positive cell fraction of MDS92 cells in combination with IL-3 or Steel factor. This cell line will be a useful tool for the study of MDS stem cells, but the mechanism of commitment of differentiation in MDS stem cells remains unknown.

Differential requirements of CD45 for lymphocyte development and function

CD45 exon 6-deficient mice show a profound block of thymocyte development at a transitional differentiation step from immature CD4+ CD8+ to mature single-positive cells. Only a few T lymphocytes are observed in the periphery of such animals, but B cell development is not affected. We investigated whether mature B lymphocytes in CD45 exon 6-deficient mice have normal functions in the absence of CD45 expression and show here that CD45-defective B lymphocytes from CD45 exon 6-deficient mice have intact B lymphocyte functions, including T-dependent and T-independent antigen-specific antibody production and class switching in vivo if normal CD4+ T lymphocytes were adoptively transferred into the mutant mice. From these results, we conclude that CD45 expression on B lymphocytes is not essential for B cell responses following antigen stimulation in vivo. However, CD4+ T helper function was severely diminished in CD45 exon 6-deficient mice, suggesting that the requirements of CD45 molecules in antigen-specific response and development are different between T and B lymphocytes.

[A case of one stage-repair of interrupted aortic arch and ventricular septal defect in neonate using a separated cardiopulmonary bypass]

We report a case of one stage-repair of interrupted aortic arch and ventricular septal defect in neonate. The operation was performed at the age of 14 days. After a median sternotomy incision, a separated cardiopulmonary bypass was commenced through the ductus and a 4 mm EPTFE graft which was anastomoted to the right subclavian artery. Cerebral circulation was maintained through the graft during reconstruction of the aortic arch. Our method is useful regarding that brain damage can be avoided which may be induced by total circulatory arrest.

Creatine phosphokinase-linked immunoglobulin associated with hypokalemic myopathy

We present three women with hypokalemic myopathy in whom serum creatine phosphokinase (CPK) was bound to serum immunoglobulin (macro-CPK). In all three cases, CPK isozyme electrophoresis demonstrated an extra CPK band between CPK-MM and CPK-MB. The bound immunoglobulins were identified as IgA/A-kappa and lambda, IgA-lambda and IgA-kappa and lambda, respectively. In all cases, histological examination of the biopsied muscles revealed necrotic and/or regenerating fibers. In each patient, potassium replacement therapy returned the macro-CPK as well as the marked elevations of serum muscle enzymes to normal. Taken together with other recent reports, our findings suggested that CPK-immunoglobulin binding may be related to the emergence of pathophysiology of hypokalemic myopathy.

Cyclin I: a new cyclin encoded by a gene isolated from human brain

A new member of the cyclin family has been isolated from an equalized cDNA library derived from human forebrain cortex. This putative cyclin, designated cyclin I, contains a typical cyclin box near the N-terminus and a PEST sequence near the C-terminus. Cyclin I shows the highest sequence similarity in the cyclin box to cyclins G and E, while the similarity between cyclins I and G also extends toward the C-terminus from the cyclin box. Cyclin I mRNA was expressed at high levels in postmitotic tissues, including skeletal muscle, heart, and brain, and was expressed constantly during cell cycle progression. The expression of cyclin I mRNA does not correlate directly to the cell cycle, and therefore cyclin I may be a novel cyclin member that functions independently of the cell cycle control.

Influence of partial hepatectomy in dogs on trimethadione metabolism and microsomal monooxygenases

1. The recovery of trimethadione (TMO) metabolism and its association with liver weight and the activity of TMO N-demethylase have been reported in rat following partial (68%) hepatectomy. In the present study, we examined the effect of liver regeneration on hepatic P450 isozymes and TMO metabolism in dog. 2. The ratio of dimethadione (DMO), being the only TMO metabolite, to TMO at 2 h after i.v. injection of TMO (4 mg/kg) fell to 80% of that in the preoperative animals by 24 h after hepatectomy. The DMO/TMO ratio gradually recovered from days 7 to 14, and by day 21 after hepatectomy it had increased to about 25%. At 28 days post-hepatectomy the ratio had returned to preoperative levels. 3. The activity of benzphetamine N-demethylase, TMO N-demethylase, p-nitro-anisole O-demethylase and aniline hydroxylase increased 3 days post-hepatectomy, exhibiting levels 4.77, 3.45, 1.51 and 1.91 times greater respectively than that of the preoperative liver in the same animal. Two weeks post-hepatectomy these activities had returned to normal. The activity of the 16 beta- and 2 beta-hydroxylation of testosterone was unchanged. However, the activity of 6 beta-hydroxylase decreased 7 days post-hepatectomy, while 16 alpha-hydroxylation had increased at 3 and 7 days post-hepatectomy compared with controls. 4. The changes in liver weight were nearly restored to preoperative levels 7 days post-hepatectomy. 5. Although the P450 content was unchanged from days 1 to 7 post-hepatectomy, it had decreased by 30% at day 14 and by 20% at day 28. The P4502B11 content 3, 7 and 14 days post-hepatectomy had increased 8, 10 and 2 times respectively, while the P4503A12 content at 7 and 14 days decreased by 30 approximately 50% compared with that of the pre-operative liver. 6. The data presented above do not reveal any relationship between P4502B11 induction and liver regeneration. The reason for such a change is unknown, therefore further investigation needs to be carried out.

Visceral fat accumulation and cardiovascular disease

Classification of Obesity. It has been noted that the incidence of metabolic complications among equally obese subjects differs depending on their physique (11) and there has been more scientific assessment in recent years that complications such as diabetes mellitus or hyperlipidemia are related to adipose tissue distribution (5). In 1983, we reported a method for adipose tissue analysis using computed tomography (CT), which enables the analysis of adipose tissue in the body cavity, e.g., abdominal cavity or thoracic cavity, as well as subcutaneous fat (10). Using this method, we found that the patients with accumulation of fat in the abdominal cavity have a higher incidence of complication (1). Based on this finding, we proposed a classification into visceral fat obesity by visceral fat area (V)/subcutaneous fat area (S) ratios obtained from CT cross sectional pictures of the umbilical region. We divided obese subjects at a V/S ratio of 0.4, classifying those with a ratio of 0.4 or more as a visceral fat obesity group and those with V/S ratio of below 0.4 as a subcutaneous fat obesity group. Disorders of glucose and lipid metabolism were more marked in the visceral fat obesity than subcutaneous fat obesity even when sex and age were matched. We also demonstrated that visceral fat obesity is more frequently accompanied by circulatory disorders such as left ventricular enlargement (8) and hypertension than subcutaneous fat obesity (2).

Age-related changes in postural control and locomotion

Age-related changes in both postural control and locomotion were investigated. Postural control was evaluated by magnitude of body sway for 131 healthy persons aged 21 to 84 years. Locomotion was evaluated by walking velocity for 217 healthy persons aged 21 to 88 years. Analysis showed that both abilities deteriorated for older persons and particularly age-related changes were more remarkable in locomotion.

Cardiac effects of methylmethacrylate in the rat heart-lung preparation with or without volatile anesthetics

We have assessed the deleterious effects of methylmethacrylate (MMA) on cardiac function and metabolism in the isolated heart-lung preparation with or without volatile anesthetics. Wistar rats were prepared for the heart-lung model. They were randomly divided into 5 groups as follows. (1) Control (C) group. (2) Cement (M) group; they received MMA. (3) Halothane (H) group; they received MMA and 1% halothane. (4) Isoflurane (I) group; they received MMA and 1.5% isoflurane. (5) Sevoflurane (S) group; they received MMA and 2.5% sevoflurane. MMA 1000 micrograms/ml was administered 7 min after the start of perfusion except in the C group. At the end of the experimental period, the hearts were freeze-clamped and then myocardial high energy phosphates, lactate and glycogen were measured. Cardiac output in all groups but C group decreased significantly. PO2 of the perfusion blood in the M, H, I and S groups was significantly lower than that in the C group. Myocardial ATP in the M, H, I and S groups was significantly lower than that in the C group. ADP and AMP in the M, H, I and S groups were higher than those in the C group. There were no significant differences in lactate and glycogen levels between the 5 groups. MMA 1000 micrograms/ml is much higher than the blood level (0.05-31.89 micrograms/ml) which was reported in clinical patients who had femoral prosthesis. Therefore, the direct contribution of MMA itself to cardiac depression may be less than the other factors such as embolism in clinical situations. Volatile anesthetics did not influence the deleterious effects of MMA on cardiac function and metabolism.

[Correlationship between proliferating cell nuclear antigen (PCNA) expression and clinicopathological factors in colorectal cancer]

Forty paraffin-embedded samples of colorectal cancer were subjected to analysis of PCNA expression. The results were expressed as a PCNA labeling rate, defined as the percentage of the number of cells with nuclear staing/the total number of tumor cells counted. The mean labeling rate was 49.4 +/- 14.1%. There was no association between labeling rate and tumor size, gross type, histologic type, presence of lymph node metastasis, lymphatic vesel invasion, venous invasion, peritoneal metastasis. The rate, however, tended to be higher in cases with infiltration to other organs and hematogeneous metastasis positive than in cases without infiltration to other organs and hematogenous metastasis, respectively.

Reduced natriuretic response to increased renal interstitial hydrostatic pressure in Dahl salt-sensitive rats during volume expansion

Renal interstitial hydrostatic pressure (RIHP) plays a key role in the link between renal hemodynamics and the rate of the tubular reabsorption of sodium and water. Our objective was to determine whether the natriuretic response to a rise in RIHP induced by acute saline infusion would be altered in prehypertensive, Dahl salt-sensitive (DS) rats. We compared the effects of an acute saline load (2.5 ml/100 g BW over 30-min) on RIHP and urinary sodium excretion in Dahl salt-resistant (DR) (n = 11) and DS rats (n = 11) maintained from birth on a low-sodium diet. Baseline mean arterial pressure, glomerular filtration rate rate, and urinary sodium excretion did not differ between DR and prehypertensive DS rats. Urine flow rate and urinary sodium excretion increased significantly in both groups following saline loading. Increases were significantly (p < 0.05) less in the prehypertensive DS rats (0.32 +/- 0.07 to 3.62 +/- 0.79 microEq/min) than in the DR rats (0.71 +/- 0.22 to 6.30 +/- 1.35 microEq/min). RIHP also increased significantly in both groups, but did not differ significantly in DR (7.3 +/- 1.1 to 9.7 +/- 1.7 mmHg) vs. DS rate (7.9 +/- 1.0 to 9.8 +/- 1.3 mmHg). At an equal mean arterial pressure, DS rats showed a reduced natriuretic capacity after an acute saline load, prior to the development of hypertension. Renal tubular sensitivity to the increased RIHP that was induced by an acute saline load was blunted in prehypertensive DS rats.

[Experimental study on effects of a high-sugar diet and physical exercise on serum phospholipids in young adults]

The life style of young adults has been receiving attention with a view to its improvement to prevent coronary heart diseases (CHD) later in life. In this study, to determining the influence of different life styles on the serum phospholipids level, we carried out experimental studies on the effects a high sugar diet and physical exercise on serum phospholipid levels. Considering the trend for young people to consume large quantities of carbonated drinks, in which most of the sugar is sucrose, we tested the effect of a high carbohydrate diet on one group of six healthy male subjects and did not find that it caused a significant increase in the serum phospholipids level. In another group of 108 healthy young female subjects, a mild exercise regimen results in a slight, but significant decrease in the serum phospholipid level (p < 0.01). The serum total cholesterol level of the group did not exhibit a significant change.

[Experience with the Groshong port in a home TPN patient--a case report]

We experienced a home TPN patient using Groshong port. A 45-year-old woman, recurrent pancreatic head cancer, was treated with home TPN. The Groshong port was inserted via external jugular vein and stayed at home for 8 months with home TPN. Lipid emulsion was administered twice a week. After administration of lipid emulsion, 20 ml of saline was injected and catheter lock was performed with only saline. Heparin was not used for catheter lock. After 8 months' home TPN, patient died. We could not find any precipitate in the catheter and reservoir. A unique feature of Groshong port is a pressure-sensitive two-way valve at the intravascular end. The valve of this port opens outward during fluid infusion or bolus injection. During blood withdrawal, the valve opens inward and then closed after the procedure. Because the valve is designed to remain closed between -7 and 80 mmHg, it will not open spontaneously under normal central venous pressure conditions. This valve eliminates the need for heparin flusing. Catheter obstruction during prolonged TPN is a serious complication. Compound of heparin, lipid emulsion and electrolytes, especially calcium is now becoming one of the most important causes of catheter obstruction and catheter removal. We used the Groshong port to prevent catheter obstruction. After 8 months' use of this port, no precipitate was found in this port. We conclude that the Groshong port is useful for home TPN catheter because it can prevent catheter obstruction due to heparin-lipid-electrolytes compound.

[Outpatient chemotherapy with continuous infusion of 5-fluorouracil (CI 5-FU) and intravenous bolus leucovorin (IVB LV) in advanced gastrointestinal cancer: the second report]

This study was designed to evaluate the efficacy, toxicity, and quality of life (QOL) of outpatient chemotherapy with 5-FU and LV in advanced gastrointestinal cancer. Treatment consisted of CI 5-FU 450 mg/body/day, days 1-28, IVB LV 30 mg/body q wk (schedule, sch. A) and CI 5-FU 200 mg/m2/day, days 1-28, IVB LV 20 mg/m2 q wk (sch. B). 5-FU was administered with the Baxter infusor (0.5 ml/hr). Oral UFT (400-600 mg/day) was administered after these chemotherapy. Sixteen patients (pts) (sch. A 9 pts, sch. B 7 pts) with advanced gastrointestinal cancer have been treated to maintain the efficacy of prior inpatient chemotherapy. Twenty pts treated as adjuvant chemotherapy were added to evaluate toxicity and QOL. The median time to progression in sch. A was 3.0 months and sch. B was 2.4 months. Grade 3 or 4 toxicities of mucositis were seen 40% in sch. A and 0% in sch. B. Grade 1 or 2 skin toxicities were seen 100% in sch. A and 52% in sch. B. Mean score of QOL in sch. A was 78.0 +/- 11.5, sch. B was 89.5 +/- 7.8 ranked between inpatient chemotherapy (5-FU + CDDP 59.0 +/- 13.8) and UFT (91.8 +/- 6.1). In conclusion, these schedule of 5-FU and LV combination offers a high patient QOL and is suitable for advanced gastrointestinal cancer treatment.

Chloroplast ribonucleoproteins (RNPs) as phosphate acceptors for casein kinase II: purification by ssDNA-cellulose column chromatography

Using ssDNA-cellulose column chromatography, a 34 kDa ribonucleoprotein (p34) has been purified from a 0.4 M KCl crude extract of spinach chloroplasts as an effective phosphate acceptor for casein kinase II (CK-II) in vitro. Monomeric and oligomeric CK-IIs were copurified with p34 by the column chromatography and the kinases were separated from p34 by means of Mono Q column chromatography. It was found that (i) the purified p34 (pI 4.9) was phosphorylated specifically by CK-II in vitro; and (ii) similar polypeptides, such as p35 (pI 4.7) and p39 (pI 4.9) in maize and p33 (pI 4.7) in liverwort, were detected as ssDNA-binding chloroplast proteins phosphorylated by CK-II in vitro. The findings suggest that (i) RNPs that function as phosphate acceptors for CK-II exist commonly in chloroplasts among plant cells; and (ii) the physiological activity of RNPs is regulated by their specific phosphorylation by CK-II in chloroplasts.