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Biomedical subjects

H Sakai

Publications and source records attributed to H Sakai.

At least 451 records · Page 25Linked to original sources
PubMed1997

Transient expression of goat growth hormone gene in poplar (Populus alba L.) protoplasts: a quick method for detection of foreign gene expression in mRNA level.

We developed a sensitive, accurate, and fast method to detect foreign gene expression using reverse transcriptase-mediated polymerase chain reaction (RT-PCR) in poplar tree (Populus alba L.) protoplasts. Template total RNA was purified by removing the transfected foreign gene vector completely with DNase I treatment before the RT reaction. Expression of cDNA that encodes goat growth hormone was confirmed at the mRNA level 24 h after electroporation mediated DNA transfer.

Animals↗
PubMed1997

Increased circulating levels of insulin-like growth factor-I and decreased circulating levels of insulin-like growth factor binding protein-1 in postmenopausal women with endometrial cancer.

In human endometrium insulin-like growth factor binding protein (IGFBP)-1 inhibits the mitogenic action of insulin-like growth factor (IGF)-I by inhibiting the binding of IGF-I to its receptor. Our purpose was to compare circulating levels of IGF-I and IGFBP-1 in women with and without endometrial cancer. We assessed circulating levels of IGF-I and IGFBP-1 and IGFBP-3 in 23 patients with endometrial cancer, 11 patients with uterine cervical cancer and 27 healthy control women. The mean circulating level of IGF-I decreased significantly following menopause but was not correlated with age in the control group. The body mass index was significantly higher in the endometrial cancer group than in the control group. Analysis of covariance showed that even after the data were adjusted to eliminate the influence of the body mass index, the circulating IGF-I concentration was higher in postmenopausal endometrial cancer patients than in postmenopausal control subjects. The mean circulating level of IGFBP-1 was significantly lower in postmenopausal cancer patients than in postmenopausal control subjects. There were no significant differences in the serum levels of IGF-I and IGFBP-1 in the patients with cervical cancer and the control group. In conclusion, an increased circulating concentration of IGF-I and a decreased circulating concentration of IGFBP-1 are associated with endometrial cancer especially in postmenopausal women.

Adult↗
PubMed1997

Interactive communication in high-technology home care: videophones for pediatric ventilatory care.

OBJECTIVE: To develop and to assess the clinical impact of a near-television quality home digital videophone system (Integrated Services Digital Network [ISDN] 64, 320 x 200 resolutions, 10 to 12 frames per second), which would provide respiratory care specialists' resources to primary care physicians and their pediatric patients receiving home respiratory care. METHOD: A prospective study comparing the preceding 6 months and following 6 months of implementation of a videophone system on seven pediatric home respiratory care patients (group I) and a prospective analytical study of three patients (group II) being introduced to home ventilatory care were carried out. Clinical effectiveness and time-saving benefits were studied. RESULTS: There were large reductions in the number of house calls by the physicians (from 5 to 0), unscheduled hospital visits by patients (from 24 to 5), and hospital admission days (from 22 to 10), with a fivefold increase in phone calls (from 11 to 58) in group I. This reduced the net number of hours spent by both patients and physicians in unscheduled medical care by 95 hours for the patients and 51.2 hours for the physicians. A total of 45 videophone calls, of which 27 were related to mechanical concerns and 18 to medical concerns, were made in group II. There were 7 mechanical and 10 medical problems of clinical significance, but all were directly handled by physicians by videophone. The majority (35 of 45) of videophone calls were made in the first 3-month period, indicating a decrease in nonspecific concerns after this period. The specifications of the system we used were found acceptable by both patients and health care professionals. The system seemed to be useful in effectively using the time of specialists and in relieving the anxieties of families. No deleterious effects were noted. The current initial cost is substantial but rapidly falling. The running cost is similar to a regular telephone bill when one ISDN 64 line is used. CONCLUSIONS: The videophone system using ISDN 64 can now be considered a practical and effective tool to recruit specialist resources into home care and to improve the quality of pediatric home ventilatory care. This study encourages the use of videophones to help establish designated home care support systems that may extend beyond national borders and time zones.

Adolescent↗
PubMed1997

A diabetic case with hemoglobin J-Meerut and low HbA1C levels.

A diabetic patient with hemoglobin (Hb) J-Meerut and low HbA1C levels is reported. An automatic glycohemoglobin analyzer used for the determination of HbA1C revealed an abnormal peak of the peripheral blood obtained from a Japanese female with diabetes. She showed a lower HbA1C level (3.7%) than expected from her fasting plasma glucose (172 mg/dl). High performance liquid chromatography and isoelectric focusing indicated that her abnormal hemoglobin was Hb J-Meerut [alpha 120(H3)Ala-->Glu] and it accounted for 28.3% of the total hemoglobin. Abnormal hemoglobinemia should be considered when a major discrepancy between the levels of HbA1C and fasting plasma glucose is observed.

Blood Glucose↗
PubMed1997

ATP, thapsigargin and cAMP increase Ca2+ in rat hepatocytes by activating three different Ca2+ influx pathways.

The intracellular Ca2+ concentration ([Ca2+]i) in single isolated rat hepatocytes was measured using fura-2. Extracellular ATP induced La(3+)-sensitive and verapamil-insensitive Ca2+ influx together with Ca2+ release from intracellular Ca2+ stores. Incubation of hepatocytes with 2 microM thapsigargin produced a large prolonged increase in [Ca2+]i, which was insensitive to both 100 microM La3+ and 40 microM verapamil. Incubation with 1 mM dibutyryl cAMP increased [Ca2+]i in the presence of extracellular Ca2+ but did not in the absence of extracellular Ca2+, indicating that dibutyryl cAMP induces Ca2+ influx which was found to be sensitive to both La3+ and verapamil, without mobilizing Ca2+ from the intracellular pools. This study shows the presence of at least 3 different Ca2+ influx pathways in the plasma membrane: that is, 1) the ATP-induced, La(3+)-sensitive and verapamil-insensitive pathway; 2) the thapsigargin-induced, La(3+)-insensitive and verapamil-insensitive pathway; and 3) the cAMP-induced, La(3+)-sensitive and verapamil-sensitive pathway.

Adenosine Triphosphate↗
PubMed1997

Aspirin-induced asthma as a risk factor for asthma mortality.

We have recently reported severe airway obstruction and bronchial hyperresponsiveness (BHR) in fatal asthma compared with patients without a history of near-fatal asthma. Based on these findings, we evaluated whether aspirin-induced asthma (AIA) is a risk factor for asthma mortality by analyzing pulmonary function and BHR. FEV1.0% and methacholine inhalation threshold were significantly lower in the fatal asthma group compared with the AIA and non-AIA groups. However, there were no significant differences between the AIA and non-AIA groups. Our results suggested that AIA is not a risk factor for asthma mortality if avoidance of aspirin and aspirin-like drugs is assured.

Adult↗
PubMed1997

The oxygen carrying capability of hemoglobin vesicles evaluated in rat exchange transfusion models.

To evaluate the oxygen transporting capability of Hemoglobin vesicles (HbV) the physiological responses to 40% and 90% exchange transfusions with HbV in anesthetized rat were observed. Hb concentration of HbV dispersions is 10 g/dL. HbV dispersed in phosphate buffered saline and HbV dispersed in 5% albumin solution were used as samples for 40% and 90% exchange transfusions, respectively. HbV surface-modified with polyoxyethylene (HbV-Poe) was also used in the 90% exchange transfusion. As controls, phosphate buffered saline, 5% albumin solution, and HbV containing methemoglobin and therefore deprived of oxygen transporting capabilities (metHbV) were administered as non-oxygen carrying fluids and washed rat red blood cells (ratRBC) as an oxygen carrying fluid. Measurements included mean arterial pressure, arterial blood gas analyses, aortic blood flow and renal cortical tissue oxygen tension. At the completion of the exchange transfusion renal cortical tissue oxygen tensions along with oxygen delivery and consumption were sustained almost equally well with the HbV dispersion compared to the washed rat red blood cell dispersion, but declined significantly in the phosphate buffered saline and albumin solutions. These results indicated that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells. In the HbV-Poe group, aortic blood flow was sustained higher in comparison to the HbV group. As for the blood gas parameters, pH and venous oxygen tensions in the HbV-Poe group tended to be higher than those in the HbV group.

Animals↗
PubMed1997

Significance of urinary type IV collagen in patients with diabetic nephropathy using a highly sensitive one-step sandwich enzyme immunoassay.

Urinary concentrations of type IV collagen in patients with diabetic nephropathy were measured by a highly sensitive, one-step sandwich enzyme immunoassay. Samples from 298 patients with noninsulin-dependent diabetes mellitus (NIDDM) and 80 healthy controls were examined. In diabetic patients with macroalbuminuria or renal insufficiency, the concentrations of urinary type IV collagen were significantly higher than those of diabetic patients with normoalbuminuria or healthy controls (P < 0.001). Urinary type IV collagen concentration in diabetic patients with microalbuminuria was significantly higher than that in diabetic patients with normoalbuminuria or that in healthy controls (P < 0.001). In contrast, there were no significant changes in the concentration of serum type IV collagen between microalbuminuric patients and normoalbuminuric patients. The area under the receiver operating characteristic (ROC) curve for the urinary type IV collagen concentration was equivalent to that of urinary albumin. It was concluded that urinary type IV collagen concentration determined using this method might be a useful marker for the early detection of diabetic nephropathy.

Adult↗
PubMed1997

Expression of thromboxane synthase in kidney tissues from patients with IgA nephropathy.

Thromboxane A2 (TXA2) is a potent vasoconstrictor which is known to be involved in the pathogenesis of experimental glomerulonephritis, although its exact pathogenic significance is not clear in human glomerulonephritis. We have investigated the expression of thromboxane synthase (TXS) in kidney tissues from patients with IgA nephropathy (IgAN), using RT-PCR and immunohistochemical methods. Biopsied renal tissues from thirty-four patients with IgAN (24 whole tissues and 10 isolated glomeruli) and normal renal tissues from 11 nephrectomized kidneys (control, eight whole tissues and three isolated glomeruli) were included in this study. TXS mRNA expression was observed in 10 out of 24 (42%) whole tissue specimens from IgAN, but no such message was disclosed in the control tissue. There was no detectable TXS mRNA expression in the isolated glomeruli either from IgAN patients or controls, although constant mRNA expressions for GAPDH and VPF/VEGF were observed. IgAN patients with positive TXS mRNA had significantly reduced GFR with elevated serum creatinine and serum beta 2-microglobulin levels. Immunostaining, using a monoclonal anti-TXS antibody, identified the localization of the TXS protein in the interstitial areas where monocyte/macrophage infiltration was abundant, as well as in the arterioles of the kidney tissues with advanced tissue damage. It was concluded that TXA2 produced by the interstitial infiltrating cells during the inflammatory process might be involved in the progression of IgA nephropathy.

Creatinine↗
PubMed1997

Standardization of low attenuation area versus total lung area in chest X-ray CT as an indicator of chronic pulmonary emphysema.

We examined the methods for measuring the LAA% (100 x low attenuation area/total lung area) on thoracic X-ray CT scans in order to develop a useful indicator of chronic pulmonary emphysema (CPE). First, we modified the method for calculating the LAA% to be applicable by the programming tool installed in a commercially available CT machine in order to minimize manual procedures. This new method proved to be applicable in all CT machines produced after 1987. Second, we examined the difference in the Hounsfield Unit (HU) between different CT machines using two kinds of phantoms. One phantom was composed of Styrofoam, which has a density similar to the low attenuation areas. The other phantom was composed of Styrofoam and water, which has a density similar to the lung. We proved that the difference of LAA% with the correct value was 5% at maximum among four different CT machines. Thus, the phantom developed in the present study may play an important role in the standardization of HU. Finally, the possibility of decreasing the X-ray levels was examined. Twenty-five percent of the standard electrical current provided the same LAA% in cases where the subject was an established CPE patient, whereas the LAA% was overestimated in subjects with a normal LAA% value. However, a correction using a linear regression equation may be possible in the latter cases. It may be concluded that LAA% analysis can easily be performed in many city hospital, without much investment of manual procedures or any corrections to the HU levels between different CT machines. This method may be useful as a routine follow up for CPE patients because of the smaller irradiated dose given when using a CT machine.

Algorithms↗
PubMed1997

[IgA nephropathy].

Explore the source record for details and available documents.

Glomerulonephritis, IGA↗
PubMed1997

Effect of ultraviolet radiation on the infectivity of Taenia taeniaeformis eggs.

The effect of ultraviolet (UV) radiation on the infectivity of Taenia taeniaeformis eggs was observed. The eggs were exposed to various UV doses and orally inoculated to rats. The number of cysts and lesions decreased dose-dependently, and neither cyst nor lesion was observed from rats infected with eggs exposed to a total dose of 2,880 mJ/cm2 or more. For evaluation of protective role of embryophore against UV radiation, the onchospheres with/without embryophore were exposed to UV radiation. Remarkably lower numbers of cyst and lesions were observed in rats inoculated with eggs which were exposed to a total dose of 30 mJ/cm2 or more after removal of embryophore. These results suggested an importance of the protective function of the embryophore in the protection against UV radiation.

Animals↗
PubMed1997

A case of successfully treated giardiasis in pancreas.

We report a case of giardiasis in the pancreas in a patient with diabetes mellitus. The patient is interesting in the following: 1) Giardia lamblia was found only in the pancreas and not in the gall bladder by cytology on endoscopic retrograde cholangiopancreaticography (ERCP) and by cerulein-secretin test (CST). 2) ERCP revealed multiple small cysts scattered throughout the pancreas. 3) Decreased pancreatic exocrine function was recovered by treatment with metronidazole.

Aged↗
PubMed1997

[Functions of the transforming growth factor-beta superfamily in eyes].

One human body is composed of 6 x 10(13) cells, and eyes are also composed of many cells of different functions. The cellular functions and intercellular interaction are regulated by many regulators including cytokines and growth factors to maintain the homeostasis. The transforming growth factor-beta (TGF-beta) superfamily, a large family of multifunctional factors, regulates various cellular functions, including cellular proliferation, migration, differentiation, apoptosis and extracellular matrix production. The TGF-beta superfamily contains about 30 multifunctional factors, and is divided into several families according to the sequence homology. The TGF-beta family, the activin family, and bone morphogenic proteins belong to the TGF-beta superfamily. TGF-beta superfamily members transduce signals through type I and type II serine/threonine type transmembrane receptors. The signals are transduced from receptors through nuclei by Smad family members, which are phosphorylated by the activated type I receptors and translocate from cytoplasm into nuclei. TGF-beta family members and the TGF-beta superfamily receptor family are expressed in ocular tissues including the cornea, ciliary epithelium, lens epithelium, retina, and blood vessels. This observation suggests the importance of the TGF-beta superfamily in eyes. Smad family members (Smad 1, Smad 2, Smad 3 and Smad 4) are expressed in the cultured retinal pigmant epithelial cell line (D407), in which TGF-beta and activin A stimulate the translocation of Smad 2, but not Smad 1 into nuclei, whereas bone morphogenetic protein (BMP) stimulates that of Smad 1, but not Smad 2. TGF-beta superfamily members play important roles in the pathogenesis of retinal neovascularization and in the wound healing process of corneal tissue. TGF-beta inhibits the endothelial functions, but, stimulates angiogenesis in vivo. TGF-beta is involved in the formation of abnormal connective tissue in corneal wound healing. In these processes, many cytokines and growth factors are involved, interacting with each other and forming networks. It is mandatory to clarify the networks to investigate molecular pathogenesis and new therapeutic agents.

Diabetic Retinopathy↗
PubMed1997

An interpretation of the internal desynchronizations based on dynamics of the two-process model.

Daan's two-process model is known to be one of the most powerful models, covering various situations from free-running to sleep deprivation. In this study, bifurcation properties of the model dynamics are clarified using a circle map. In addition, the two-process model is applied to simulate the two distinct patterns (the period-prolonged: I and the period-shortened: II) of sleep-wake cycles during internal desynchronizations. We propose the novel interpretation that types I and II could be regarded as mutual entrainments between the body temperature rhythm and the sleep-wake cycle with the period ratios 3:4 and 3:2, respectively. From the bifurcation properties of the two-process model obtained above, the model is shown to be able to generate the respective type of mutual entrainment with an appropriate range of a parameter value, i.e, a gap between thresholds. The variable behavior of human circadian rhythm is suggested to be systematically understood based on the bifurcation properties of the two-process model.

Activity Cycles↗
PubMed1997

[A case of posterior nutcracker syndrome occurring in pregnancy].

We have encountered a 23-year-old pregnant woman with macrohematuria, which occurred from the 8th or 9th week of gestation. Blood pressure and renal function were normal during the total course of pregnancy. Macrohematuria did not disappear after childbirth. Cystoscopy was conducted and the excretion of hematuria from the left ureter was confirmed. Therefore, a left renal venogram was performed although abdominal ultrasonography and CT scanning showed no abnormality. There were two branches of the left renal vein (LRV), such as the anterior and posterior branch. The pressure gradient was 4.4 cm H2O between the anterior branch of LRV and the inferior vena cava (i.v.c.). However, a significant pressure gradient (6.6 cm H2O) was demonstrated between the posterior branch of the LRV and IVC. From these findings we diagnosed this patient as venous hypertension in the posterior branch of the left renal vein (= posterior Nutcracker syndrome, PNS). Enlargement of the uterus in pregnancy might not be important in the occurrence of PNS because macrohematuria was observed from the 8th or 9th week of gestation. Functional hemodynamic change in pregnancy might cause a widening of the diameter or a shift of the aorta, that might result in compression of the posterior branch of the left renal vein. Persistence of macrohematuria after childbirth might have been due to irreversible hemodynamic alteration by the development of co-lateral circulation. To the best of our knowledge, this is the first case of PNS occurring in pregnancy.

Adult↗
PubMed1997

Synthesis of guanosine 5'-triphosphate analogues and their effect on microtubule assembly.

More than 20 base-modified analogues of guanosine 5'-triphosphate including 2'-deoxyguanosine derivatives were synthesized and examined their effect on tubulin polymerization into microtubules (Mts). Among those, 2,6-diamino-8-oxopurineriboside 5'-triphosphate (1d), 2,6-diamino-2'-deoxypurineriboside 5'-tri phosphate (1b) and 8-bromoguanosine 5'-tri phosphate (1g) were shown to have remarkable effect to promote microtubule assembly.

Guanosine Triphosphate↗