Dietary regulation of sucrase-isomaltase gene expression in rat jejunum.

We have previously demonstrated that intake of fat as well as carbohydrate affects the activity and immunoreactive amount of sucrase-isomaltase (S-I) in rat jejunum. To examine whether diet-related changes in sucrase and isomaltase activities are accompanied by the variations of sucrase-isomaltase mRNA levels, 7-week-old rats were fed either a high-long-chain triacylglycerols diet (73 energy% as corn oil), a high-medium-chain triacylglycerols (MCT) diet (66 energy% as MCT, 7 energy% as corn oil) or a high-carbohydrate diet (70 energy% as corn starch) for 7 days. Northern blot analysis revealed that S-I mRNA levels were abundant in the jejunum of rats fed the high-MCT diet; the levels were similar to those in the rats fed the high-carbohydrate diet. Force-feeding a high-sucrose diet (40 energy% as sucrose) brought about a parallel rise in both S-I mRNA and sodium/D-glucose cotransporter (SGLT1) mRNA levels within 12 h. Force-feeding the high-MCT diet also produced an elevation of S-I mRNA and SGLT1 mRNA. However, force-feeding a diet containing alpha-methylglucoside, a non-metabolizable but actively transported sugar, did not increase S-I mRNA or SGLT1 mRNA level; sucrase activity was nevertheless elevated by feeding alpha-methylglucoside diet. These results suggest that not only carbohydrate intake but also MCT intake might influence S-I mRNA and SGLT1 mRNA levels in the jejunum, presumably through common metabolite(s) of carbohydrates and MCT, and that carbohydrate may play another role in enhancement of the sucrase activity through modulation of translation and/or posttranslational modifications of the sucrase-isomaltase complex.

Dietary fat regulates cellular retinol-binding protein II gene expression in rat jejunum.

Cellular retinol-binding protein II (CRBP II) is an abundant cytosolic protein of intestinal absorptive cells. In this study, we examined whether dietary fat modulates the expression of CRBP II in the small intestine. In the rats fed a diet rich in long-chain triacylglycerols (LCT), both CRBP II mRNA and CRBP II protein levels in the jejunum were more than two-fold greater than in the rats fed a low fat diet and a diet rich in medium-chain triacylglycerols (MCT). The mRNA abundance of a retinoid X receptor (RXR alpha), which is thought to interact with the cis-element located in the CRBP II promoter, was elevated in the jejunum of rats fed high-LCT and high-MCT diets as compared with that of animals fed a low-fat diet, but the levels of RXR alpha mRNA of the LCT diet group was similar to that of MCT diet group. These results suggest that the expression level of the CRBP II gene is not directly related to the RXR alpha expression, and that it might be modulated by long-chain fatty acids or their metabolites.

Effect of chemotherapy combined with caffeine for osteosarcoma.

Nine patients with osteosarcoma were treated by chemotherapy combined with caffeine and surgery. All primary tumors showed complete histological response to preoperative chemotherapy consisting of three intraarterial infusions of cisplatin and caffeine without/with doxorubicin and two systemic high-dose methotrexate combined with vincristine. Limb-salvage surgery was performed in eight patients with marginal procedure, which led to the preservation of good limb function. Below-knee amputation was done in one patient with calcaneal osteosarcoma. There has been neither local recurrence nor lung metastasis in seven patients with conventional osteosarcoma during a median follow-up period of 28 months. Lung metastases leading to death were observed in one patient with small-cell osteosarcoma despite complete destruction of the primary tumor by preoperative chemotherapy. Chemotherapy combined with caffeine administration deserves further extensive and large-scale study in osteosarcoma.

Intraarterial Cisplatin and caffeine with/without Doxorubicin for musculoskeletal high-grade spindle-cell sarcoma.

We report on the effects of intraarterial cisplatin and caffeine with/without doxorubicin on high-grade spindle cell sarcomas of bone and soft tissue based on the fact that caffeine enhances cytocidal effects of DNA-damaging agents. Intraarterial cisplatin and caffeine with/without doxorubicin was preoperatively given three times to ail patients and two courses of high-dose methotrexate with the citrovorum factor and vincristine were administered to the patients with skeletal spindle cell sarcoma. Tumor response was assessed radiographically and histologically. Seventeen (90%) of 19 patients with bone sarcoma and 7 (70%) of 10 patients with soft-tissue sarcoma showed good response. All patients with osteosarcoma demonstrating good radiological response underwent marginal excision without subsequent local tumor recurrence. Histologically, there were no viable cells in resected specimen of 14 patients with bone sarcoma. Other 8 cases with soft-tissue sarcoma treated by unplanned surgery were included to assess side effects. Twenty-five out of 37 patients are still free of disease. There was local tumor recurrence in 2 patients who did not respond to the chemotherapy. Toxic effects noted in the clinical study included moderate myelosuppression, nausea and vomiting, renal insufficiency and cutaneous injury. No toxic effects were directly attributable to 1.2-1.5 g/m(2) caffeine. The intraarterial infusion of cisplatin and caffeine combined with/without doxorubicin was tolerable in all patients and led to good response in high-grade spindle cell sarcomas. In patients with good response, limb-salvage surgery can be conducted safely without local relapse and good limb function is preserved by chemotherapy and marginal excision.

Inhibitory effect of caffeine on potentially lethal damage repair in cisplatin-treated human osteosarcoma cells.

Human osteosarcoma cells, that were cultured to confluence and maintained under low nutrient conditions, showed potentially lethal damage repair after cisplatin treatment. This repair was inhibited by a non-toxic dose of caffeine. Flow cytometric analysis indicated that cisplatin-treated cells accumulated in the S phase by 24 hr, followed by accumulation in the G2/M phase. Caffeine inhibited the initial accumulation in the S phase and the release of cells from the G2/M block. DNA synthesis was also inhibited by the cisplatin treatment. The addition of caffeine significantly reversed this inhibition. The content of DNA-bound platinum decreased over time after cisplatin treatment. Caffeine did not influence platinum content, nor did it directly affect the DNA excision repair. Cisplatin inhibits DNA synthesis in the S phase, but caffeine reduces this inhibition. Caffeine-treated cells that pass through S phase are incapable of recovery.

Cannulation of simple bone cysts.

We describe a consecutive series of 26 patients with simple bone cysts who were treated by curettage, multiple drilling and continuous decompression by the insertion of either a cannulated screw or a pin. In the first 15 patients we used titanium cannulated screws (group 1) and in the next 11 a cannulated hydroxyapatite pin (group 2). Satisfactory healing was achieved in 12 patients in group 1 (80%) and in all in group 2. This technique seems to be a promising option for the treatment of simple bone cysts. The cannulated hydroxyapatite pin is recommended because of its higher success rate and the fact that it does not need to be removed.

[Congenital Minamata disease accompanied by arachnoid cyst (author's transl)].

A male, born on December 8, 1956, during the period when many Minamata diseases broke out in a district. His parents who ate much fish and shell fish taken in Minamata Bay suffered from the light, incomplete Minamata disease showing sensory disturbance, the constriction of the visual field, muscular weakness, etc. He weighed 3,225 gr. upon the normal birth given 10 months after pregnancy. His abnormalities were noted since his head was not stabilized on the neck even six months after the birth. Because of the delay in the development of the motor function, he became barely able to sit, stand up and begin walking at the ages of 3, 5 and 6 respectively. In 1962 (at the age of 6), his congenital Minamata disease was diagnosed in view of his clinical symptoms and epidemiological conditions. The mercury value in the hair and blood upon the birth is not known because a considerable time had elapsed after the birth when his mercury poisoning was discovered. However, the clinical symptoms included intelligence disturbance, character change, dysarthria, primitive reflexes, strabismus, hypersalivation, ataxia and hyperkinesia, indicating a typical congenital Minamata disease. Until he became 13 years old (1969) or so, his mental and motor function developed, both gradually. In the same year, he was admitted to a special class for the handicapped. EEG examination revealed that there was a slow alpha activity in the basic pattern and that 6 Hz positive spike was found in the sleep EEG. The constriction of the visual field was classified through examination.2+

[Combined effect of cisplatin and caffeine on murine B16-BL6 melanoma cells].

Combined effect of cisplatin and caffeine on murine B16-BL6 melanoma cells was studied. Synergistic inhibition of the cell growth was observed when caffeine (2 mM) was added continuously after one hour exposure of cisplatin. On the other hand, when caffeine was added before one hour exposure of cisplatin or one hour simultaneous exposure with cisplatin, synergistic effect was not shown. In the analysis of DNA histogram obtained from flow cytometry, S and G2/M accumulation was observed by the treatment of cisplatin and that accumulation was reduced by the combination of cisplatin and caffeine. From this findings, it was suggested that caffeine would inhibit DNA repair process. Furthermore, according to morphological studies with hematoxylin-eosin stain and Fontana-Masson stain, the addition of caffeine alone resulted in mild swelling of melanoma cells and the decrease of nuclear-cytoplasmic ratio. The combination of cisplatin and caffeine caused marked swelling of melanoma cells and remarkable increase of dendrite-like processes. Melanogenesis was also enhanced by the addition of these two drugs. Many matured melanosomes, increases of mitochondria, Golgi's apparatus and endoplasmic reticula were observed by the use of electron microscope. These findings implied that the combination of cisplatin and caffeine induced a differentiation of murine melanoma cells.

[Intra-arterial infusion of cisplatin and caffeine for a recurrent malignant fibrous histiocytoma].

We treated a 43-year-old man with recurrent malignant fibrous histiocytoma in right distal femur with intra-arterial infusion of cisplatin and caffeine 5 years after wide excision and chemotherapy. At the time of the first recurrence in the lateral aspect of thigh, intra-arterial infusion of CDDP (120 mg/m2) was ineffective. We treated him with radiation (7000 rad), and there was no evidence of tumor by radiological evaluation. The second local recurrence was treated with intra-arterial infusion of CDDP (120 mg/m2/1 hour) and caffeine (1.2 g/m2/24 hours x 3 days), and the tumor disappeared, radiologically and histologically. Caffeine did not increase the nephrotoxicity of CDDP, and no insomnia nor palpitation was seen. Intra-arterial infusion of CDDP and caffeine could be useful to increase the effect of CDDP for regional chemotherapy.

[Angiotensin II-induced hypertension chemotherapy of bone and soft-tissue sarcomas].

We treated 14 patients with high grade sarcomas by angiotensin II-induced hypertension chemotherapy. The chemotherapy protocol described by Rosen was selected according to histological classification of sarcomas (small cell sarcoma, spindle cell sarcoma, pleomorphic sarcoma). The level of angiotensin-induced hypertension was one and half times as high as blood pressure at rest. Induced hypertension was maintained for 30-60 minutes. In three cases of 5 primary osteosarcomas, induced hypertension resulted in the increase of tumor stain and/or vascularity angiographically, and chemotherapeutic effects were CR or PR. The six cases with soft-tissue sarcomas were 2 cases each of CR, PR, and NC. The decrease of relative tumor blood flow under the condition of angiotensin II-induced hypertension was detected in 5 cases of 6 soft-tissue sarcomas by 133Xe clearance method. In the case of rhabdomyosarcoma, the decrease of tumor stain and vascularity by induced hypertension was observed on angiogram. As the side effects accompanying induced hypertension, nausea and chest oppression were noted in 2 cases, respectively. In this study it was suggested that angiotensin II-induced hypertension chemotherapy was effective for osteosarcoma, but that it might be ineffective for soft-tissue sarcomas.

Lactase-phlorizin hydrolase and sucrase-isomaltase genes are expressed differently along the villus-crypt axis of rat jejunum.

Lactase-phlorizin hydrolase (LPH) and sucrase-isomaltase (SI) are two disaccharidases specifically expressed in small intestinal absorptive cells. We previously showed that the transcripts of both genes are elevated within 12 h of carbohydrate intake. To examine at which locus of villus-crypt axis this response to dietary carbohydrate occurs, 6-wk-old rats were fed a low-carbohydrate diet (5% energy) for 7 d, and then force-fed either the low-carbohydrate diet or a sucrose (40% energy) diet during the last 6 h. Cryostat sectioning of jejunal segments followed by RNA blot hybridizations of the transcripts revealed that, unlike SI mRNA which was expressed maximally in the lower villus, maximal LPH mRNA level was attained at the upper villus. The distribution of the respective immunoreactive protein and the enzymatic activity was shifted more toward the villus tips for LPH than for SI. Force-feeding the sucrose diet caused an abrupt increase in SI mRNA level in the lower villus within 3 h, while the rise in LPH mRNA level occurred in the mid- and upper-villus. The diet-induced increases in the LPH mRNA and SI mRNA levels were abolished along the entire villus by the administration of actinomycin D. These results suggest that LPH gene is maximally expressed in more apical villus cells than SI gene, and that dietary sucrose elicits enhancement of the gene expressions in the villus cells which are accumulating the respective transcripts.

Torsional rigidity of single actin filaments and actin-actin bond breaking force under torsion measured directly by in vitro micromanipulation.

Knowledge of the elastic properties of actin filaments is crucial for considering its role in muscle contraction, cellular motile events, and formation of cell shape. The stiffness of actin filaments in the directions of stretching and bending has been determined. In this study, we have directly determined the torsional rigidity and breaking force of single actin filaments by measuring the rotational Brownian motion and tensile strength using optical tweezers and microneedles, respectively. Rotational angular fluctuations of filaments supplied the torsional rigidity as (8.0 +/- 1.2) x 10(-26) Nm2. This value is similar to that deduced from the longitudinal rigidity, assuming the actin filament to be a homogeneous rod. The breaking force of the actin-actin bond was measured while twisting a filament through various angles using microneedles. The breaking force decreased greatly under twist, e.g., from 600-320 pN when filaments were turned through 90 degrees, independent of the rotational direction. Our results indicate that an actin filament exhibits comparable flexibility in the rotational and longitudinal directions, but breaks more easily under torsional load.

Growth inhibition and differentiation of murine melanoma B16-BL6 cells caused by the combination of cisplatin and caffeine.

We preliminarily investigated the combined effects of cisplatin and caffeine on murine melanoma B16-BL6 cells in vitro. When caffeine was added before or simultaneously with cisplatin, there was little growth inhibition. The addition of 2.0 mM caffeine after 1 h of exposure to cisplatin inhibited growth and induced cell differentiation. This treatment resulted in fewer cells, and the numbers of melanosomes and mitochondria and the amount of Golgi's complex and endoplasmic reticulum were increased. DNA histograms obtained by flow cytometry showed that cells treated with cisplatin alone accumulated in the G2/M phase, with a partial G2 block. The addition of 2.0 mM caffeine after 1 h of treatment with cisplatin reduced this block. Caffeine caused murine melanoma B16-BL6 cells treated with cisplatin to differentiate, and this inhibited growth.

Maffucci's syndrome combined with dedifferentiated chondrosarcoma.

We report a rare case of Maffucci's syndrome combined with dedifferentiated chondrosarcoma in the right shoulder girdle developing from pre-existing enchondroma. In this case, magnetic resonance imaging was useful in diagnosing dedifferentiated chondrosarcoma before surgery. T2-weighted imaging was used to distinguish between the cartilaginous component and the dedifferentiated one. Histologically, there was enchondroma in the humerus and grade 2 chondrosarcoma in the scapula. Further, the dedifferentiated tumor had three mesenchymal elements: osteosarcoma, malignant fibrous histiocytoma, and fibrosarcoma. This histological heterogenicity may be due to mesodermal dysplasia of Maffucci's syndrome.

Diet-induced changes in gene expression of lactase in rat jejunum.

To explore the mechanisms by which jejunal lactase activity is modified by carbohydrate and/or fat intake, mRNA levels and the absolute synthesis rate of lactase-phlorizin hydrolase (LPH) were determined in 6-wk-old rats that were fed either low-starch diets containing long-chain triacylglycerol (LCT, 73% energy as corn oil) or medium-chain triacylglycerol (MCT, 66% energy as MCT, 7% energy as corn oil), or a high-starch diet (70% energy as cornstarch) for 7 days. LPH mRNA levels in the jejunum were similar between LCT-fed and MCT-fed rats, but animals fed the high-starch diet exhibited a greater (2x) LPH mRNA level than other groups. The absolute synthesis rate of LPH, estimated by the flooding dose technique using [3H]phenylalanine, was greater (2.4x) in rats fed the high-starch diet than in other groups. A short-term force-feeding experiment revealed that sucrose was able to evoke LPH mRNA levels within 12 h but that a nonmetabolizable sugar (alpha-methylglucoside) was unable to enhance it. By contrast, animals fed the high-LCT diet showed a lower (by 30%) lactase activity than rats fed the low-starch, high-MCT diet, which was accompanied by not only a reduction of immunoreactive LPH in brush-border membranes but also a reduction in lactase activity per unit weight of immunoreactive LPH. These results suggest that both gene expression and posttranslational events of LPH might be influenced by dietary manipulations; carbohydrate intake primarily increases LPH mRNA levels, and LCT accelerates inactivation and/or degradation of lactase.

Clinical significance and management of silent myocardial ischemia in patients with angina pectoris and myocardial infarction.

The present study was canued out to clarify the relationship between silent myocardial ischemia in patients with angina pectoris and onset of myocardial infarction, and the former's prognostic significance. The peak incidences of onset of myocardial infarction in patients were at 2 a.m., 9 a.m., 2 p.m., 8 p.m., and 9 p.m., and the peak onsets of transient silent myocardial ischemia in angina pectoris patients were at 9 a.m., 2 p.m., 8 p.m., and 9 p.m. Thus the most likely onset times were almost the same with both events. Of 169 patients with coronary artery disease admitted for treatment, 128 patients had no anginal attacks during follow-up and the remaining 41 had persistent angina despite adequate medical treatment. Holter monitoring electrocardiography was performed twice with the non-angina patients, during admission. Of these 128 patients, 54 showed no silent myocardial ischemia on either of the electrocardiographic recordings, 34 showed silent ischemia with the first Holter monitoring but not with the second one, and the remaining 41 showed silent myocardial ischemia on both tests. The subsequent incidences of "cardiac events" were 9.4%, 14.7%, and 36.6%, respectively for these three groups. Therefore, it is concluded that the presence of silent myocardial ischemia is closely related to onset of myocardial infarction and is an important prognostic factor in patients with coronary artery disease.

Characteristics of symptomatic and asymptomatic myocardial ischemia during ambulatory electrocardiographic monitoring in patients with angina pectoris.

The purpose of the present study was to clarify the characteristics of myocardial ischemic attacks in patients with exertional angina (EA, 56 cases), exertional and rest angina (ERA, 28 cases), rest angina (RA, 4 cases), and variant angina (VA, 39 cases). The Holter electrocardiographic findings were compared among the four types of angina pectoris. The frequency of symptomatic ischemic attacks in descending order was 46.0% in EA, 29.0% in ERA, 28.1% in RA, and 21.6% in VA, while the frequency of asymptomatic ischemic attacks was in the reverse order. The maximal heart rates during symptomatic ischemic attacks were in descending order, EA, ERA, RA, and VA. The maximal heart rate during ischemic attacks was significantly lower in patients with spontaneous angina than in those with exercise-induced ischemia for all types of angina (p less than 0.05, respectively). Further, the difference in maximal heart rate during ischemic attacks between the ambulatory electrocardiogram and exercise test was greater in patients with RA and VA than in those with EA. Therefore, this suggests that increased coronary vascular tone is a cause of spontaneous ischemic attacks in each type of angina pectoris.

Effects of L-arginine analogues on vasomotion of isolated porcine coronary arteries.

L-Arginine analogues have been widely used to examine the role of endothelium-derived nitric oxide (NO) in vascular responses; however, the effects of the agents on coronary vasomotion are not fully understood. In this study, we examined the effects of the analogues on vasomotion of isolated porcine coronary arteries. Strips of the porcine coronary artery were suspended for isometric tension recording in Krebs-Henseleit solution. L-Arginine analogues, N omega-nitro-L-arginine methyl ester (L-NAME, 10(-9)-10(-3) M), NG-monomethyl-L-arginine (L-NMMA, 10(-9)-10(-3) M), and NG-nitro-L-arginine (L-NNA, 10(-9)-10(-3) M), caused dose-dependent contractions, which were greater in strips with than in those without endothelium. Those endothelium-dependent contractions were almost abolished by indomethacin (10(-5) M) and FeCl2 (10(-3) M). The latter reduces prostaglandin H2 to 12-heptadecatrienoic acid, which has no vasoconstrictor effect. These results indicate that the L-arginine analogues cause endothelium-dependent contractions that are mediated by prostaglandin endoperoxides and suggest that they have properties other than simple inhibition of NO synthesis in porcine coronary arteries.

Biological and structural properties of cyclic peptides derived from the alpha-amylase inhibitor tendamistat.

Six cyclic peptides with 5, 7, 9, 11, 13, and 15 amino acids, with the inhibitory sequence of the alpha-amylase inhibitor tendamistat, were synthesized. The 11-residue peptide inhibited porcine pancreatic alpha-amylase most potently (K1 0.29 +/- 0.09 microM). For the 11-residue peptide, the circular dichroism study suggested a preliminary relationship between its inhibitory activity and structural property.