PubMed Health⌕ Search

Biomedical subjects

R Kawahara

Publications and source records attributed to R Kawahara.

At least 19 recordsLinked to original sources
PubMed1995

Isolation and characterization of homeobox-containing genes of carrot.

Homeodomains (HDs) are DNA-binding domains that have been well characterized in animals, and HD proteins are thought to be regulators of transcription. To investigate the regulation of gene expression during somatic embryogenesis in carrot, an attempt was made to isolate cDNA clones that encode HD proteins. A cDNA library from carrot somatic embryos was screened with a degenerate oligonucleotide probe that corresponded to a conserved amino acid sequence of HDs, and one cDNA clone (CHB1) encoding an HD protein was isolated. The amino acid sequence deduced from the nucleotide sequence of this clone contained a putative leucine zipper motif adjacent to the anticipated HD. The homeodomain/leucine zipper (HD-Zip) sequence of this cDNA was used for further screening, and five additional independent clones (CHB2 through CHB6) were isolated. Although the HD-Zip sequences encoded by these clones were similar to each other, the sequences beyond the HD-Zip regions varied greatly. Transcripts corresponding to CHB1 through CHB6 were expressed at different times during somatic embryogenesis. In particular, transcripts corresponding to CHB2 were expressed in close association with the early development of embryos.

Amino Acid Sequence↗
PubMed1995

Isolation of a carrot gene expressed specifically during early-stage somatic embryogenesis.

We report the first successful isolation by subtractive hybridization of a gene expressed specifically during somatic embryogenesis. Embryogenic cell clusters, 32-50 microns in diameter, were isolated by sieving and density-gradient centrifugation. The cDNA library was constructed from proglobulars which were formed from embryogenic cell clusters 3 days after transfer to auxin-free modified Lin and Staba's medium. For use as probe in screening, the same cDNA used for library construction was enriched for specific sequences using subtractive hybridization. The cDNA used for subtraction was prepared from suspension cultures 5 days after subculturing in auxin-containing medium. Nine independent differentially expressed cDNA clones were obtained from a screen of 150,000 recombinant phages. Northern analysis indicated one of these, CEM6, to be expressed specifically during somatic embryogenesis. In addition, one hybridizing transcript was detected in plantlet cotyledons, and two transcripts were detected in hypocotyls. Two separate and distinct hybridizing transcripts are expressed specifically in hypocotyl tissue. The amino acid sequence deduced from the nucleotide sequence of the CEM6 cDNA indicates that it encodes a glycine-rich protein containing a hydrophobic signal-sequence like domain. Its early embryo-specific expression and sequence characteristics suggest an important role as a cell wall protein in embryogenesis.

Amino Acid Sequence↗
PubMed1995

[Amygdaloid kindling in variously aged infant rats and rekindling after maturation: epileptogenesis and its persistence].

To study amygdaloid kindling in variously aged infant rats and rekindling development after their maturation, 34 male Wistar rats were subjected to initial kindling 13 days after birth (13-day-old group, 9 rats), 16 days after birth (16-day-old group, 9 rats), 18 days after birth (18-day-old group, 7 rats), or 26 days after birth (26-day-old group, 9 rats). Each group received reoperation on the 70th day, and was subjected to rekindling 5 days after operation. Also, a control group of mature rats was initially kindled at the age of 75 days and rekindled after 2 months (75-day-old group, 11 rats). The obtained results are summarized as follows. I. Results of initial kindling: (1) a significant positive correlation was found between the age of the 4 groups of rats and the after-discharge threshold of infant rats (p < 0.05), (2) significant correlations were not found between the age of the 4 groups of infant rats and the stimulation numbers inducing C0-2 and C0-4 stage symptoms, (3) a significant positive correlation was found between the age of the 4 groups of infant rats and the stimulation number inducing C3-4 symptoms (p < 0.05). II. Results of rekindling: (1) significant negative correlations were found between the age of the 4 groups at initial kindling and the stimulation numbers inducing C0-2, C3-4 and C0-4 symptoms (p < 0.05-0.0001). III. Ratio of initial kindling and rekindling: (1) significant negative correlations were found between the age at initial kindling and the C0-2 and C0-4 stimulation number ratios (p < 0.00001), (2) a negative but not significant correlation was found between the C3-4 stimulation number ratio and age at initial kindling. These results suggest that in infant rats amygdaloid excitability is stronger, when the younger the rat, and that the later in the infant period the epileptogenesis is acquired, the stronger is it preserved even after maturation as high amygdaloid excitability.

Aging↗
PubMed1995

[Neonatal apnea after general anesthesia--effects of intraoperative hyperventilation and serum ionized Ca concentration].

The relationship between neonatal apnea following general anesthesia and serum ionized calcium (Ca2+) concentration was examined in 13 neonates who had received intraoperative hyperventilation. In all cases, preoperative serum Ca2+ concentration was within normal limits. The anesthesia was maintained by nitrous oxide and oxygen. At the end of anesthesia, the incidence of abnormal breathing such as apnea, periodic breathing or subcostal retraction and their activity were investigated. Five minutes after intravenous administration of 2% CaCl2 solution (16 mg.kg-1), the same parameters were compared with the values before CaCl2 administration. As we used only Ca2+ free solution for fluid therapy during operation, serum Ca2+ concentration decreased gradually under general anesthesia, but after CaCl2 administration, it increased and the incidence of abnormal breathing decreased. To determine the relationship between hyperventilation and the incidence of abnormal breathing, the data were analyzed by dividing the patients into two groups based on PaCO2 level, a lower PaCO2 group (intraoperative PaCO2 < 30 mmHg, n = 5) and a higher PaCO2 group (PaCO2 > or = 30 mmHg, n = 8). But there was no significant relationship between them. In conclusion, this study demonstrates that the Ca administration has a favorable effect on respiratory system and motor activity, but we cannot relate the incidence of postoperative abnormal breathing to the degree of hyperventilation.

Anesthesia, General↗
PubMed1994

Dropout of young non-insulin-dependent diabetics from diabetic care.

We investigated the follow-up status and prognosis of 109 patients with non-insulin-dependent diabetes mellitus aged from 10 to 19 years old (66 males and 43 females). Patients who had not attended hospital for at least 20 months up to the end of September 1990 were regarded as defaulters, and were surveyed by questionnaire. There were 62 defaulters (56.9%) among the 109 patients originally enrolled in diabetes care. The defaulters had a significantly higher body mass index (both males and females), mean arterial blood pressure, and fasting blood glucose level than the patients still attending the diabetes clinic, as well as a significantly worse lipid profile. The main reason given for non-attendance was a busy schedule. Compared with patients attending the diabetes clinic, a lower percentage of the defaulters remained on a diet or took regular exercise. Rapid eating was more common among the defaulters than the attendees (92.9% vs. 60%, P = n.s.). Thus, the lifestyle of the defaulters seemed to be undesirable for young diabetic patients. These findings emphasize the importance of effective education and follow-up for young obese patients with non-insulin-dependent diabetes mellitus.

Adolescent↗
PubMed1994

[Effect of REM sleep deprivation on the each seizure stage in feline amygdaloid kindling].

The effect of REM sleep deprivation (RD) on the each seizure stage in feline amygdaloid kindling (AM-K) was studied. RD for 12 hours (12-h RD) was performed by applying the platform procedure at stages 2 and 4, and immediately after RD the triggering threshold of each seizure stage and the duration of after discharge was measured. At stage 6, 12-h and 72-h RD were performed, and the generalized seizure triggering threshold (GST), the duration of after discharge, and the latency to generalized convulsive seizure (LGS) were measured. For the controls, a platform sufficiently large to allow a cat to lie down and sleep was used under the same conditions as those for RD (Non-RD). With the platform procedure employed in this study, the %REM decreased significantly to 2% of what it was before 12-h RD (p < 0.01). After the 12-h RD, the %REM and %S-2 increased significantly compared with those during the RD (p < 0.05-0.01), revealing a rebound phenomenon. After the 12-h RD, the %W-2 also showed a significant decrease (p < 0.05). The results were as follows: (1) The triggering seizure threshold of stage 2 after the 12-h RD showed a significant decrease (p < 0.01). Though the AD duration after RD prolonged than those after Non-RD, significant differences was not noted. (2) The triggering threshold and AD duration of stage 4 after 12-h RD showed no significant change. (3) GST, AD duration, LGS showed no significant change by 12-and 72-h RD. The results of present study led to the following conclusions: At stage 2 of AM-K, REM sleep increased temporarily, and consequently the REM pressure is elevated after RD so much that it lowers the triggering threshold at stage 2 of AM-K. On the other hand, at stages 4 and 6 of AM-K, REM sleep is temporarily decreased, and consequently the REM pressure is not elevated by RD so that the triggering threshold at stages 4 and 6 of AM-K were not lowered.

Amygdala↗
PubMed1993

[Two cases of tension pneumothorax caused by tracheal suction during the operation of pectus excavatum].

Rehbein's method is one of the surgical procedures for pediatric pectus excavatum, which constructs thorax by lifting and fixating the sternum using metal strut inserted into bone marrow of bilateral ribs. We experienced two pediatric cases of tension pneumothorax caused by tracheal suctioning during the operation by this method. The etiology of tension pneumothorax was thought to be as follows. A small pleural hole was made during separation of ribs from surrounding tissues and a large amount of air entered into the pleural space and check valve mechanism worked at the pleural hole when the lung was collapsed on tracheal suctioning. In anesthetic management of pectus excavatum by Rehbein's method, we should always be cautious of the possible occurrence of tension pneumothorax.

Child↗
PubMed1993

[The severity of dementia and brainstem auditory evoked potentials--the amplitude of waves I, III and V].

The correlation between the severity of dementia and the amplitudes of brainstem auditory evoked potentials (BAEPs) was studied. The subjects were 78 patients with dementia (20 males, 58 females) whose mean age was 80.5 +/- 6.7 years. Normal subjects were 9 elderly persons (2 males, 7 females) whose mean age was 79.2 +/- 6.0 years. The amplitudes of wave-I, -III and -V were measured. As for individual differences: (1) The amplitudes of BAEPs in the male group were lower than that in the female group, there was no significant difference. (2) The amplitudes of wave-V in female patients with vascular dementia were significantly lower than that of degenerative dementia. (3) The amplitudes of wave-III reduced as the duration of illness prolonged. Dividing the patients into three groups according to the severity of dementia which are mild, moderate and severe. (4) The amplitudes of the wave-V reduced significantly as the severity of dementia advanced. There was a significantly positive correlation between the amplitudes of the wave-V and the Hasegawa's dementia scores (r = 0.404759, p < 0.05) Based upon the above results, the brainstem dysfunction might progress with the severity of dementia.

Aged↗
PubMed1992

A gene expressed preferentially in the globular stage of somatic embryogenesis encodes elongation-factor 1 alpha in carrot.

We have isolated cDNA of genes that are preferentially expressed during somatic embryogenesis of carrot (Daucus carota L.) by differential screening of globular embryos and cells that are dividing in an unorganized manner. As a result of Northern-blot analysis, one of the genes identified in this way, which we refer to as CEM1, was found to be expressed at high levels in somatic embryos at the globular and heart-shaped stages. In-situ hybridization using globular embryos revealed that the mRNA transcribed from CEM1 was located preferentially in the spherical region of the globular embryo. A homology search using the amino acid sequence deduced from the nucleotide sequence of the CEM1 cDNA revealed that CEM1 encodes the eukaryotic translational elongation-factor 1 alpha.

Amino Acid Sequence↗
PubMed1992

[A case of malignant localized visceral pleural mesothelioma].

We experienced malignant localized mesothelioma of which origin was visceral pleura. According to, 1) the preoperative chest X-ray and chest CT which showed extra-pleural sign, 2) the rapid tumor growth, and 3) the result from needle biopsy, we diagnosed malignant localized mesothelioma of which origin was parietal pleura. Surgical treatment was performed, and diagnosed that its origin was visceral pleura. The tumor invaded the lung. It is dangerous to diagnose by means of needle biopsy because of malignant cell implantation. We recommend that firstly the surgical treatment should be carried out for malignant mesothelioma, which needs extended resection for preventing its recurrence.

Humans↗
PubMed1992

[Anesthetic management of a neonate with esophageal atresia with double tracheoesophageal fistulae].

We reported the anesthetic management of a 1-day-old female neonate (2,110 gm) with esophageal atresia combined with double tracheoesophageal fistulae, which is classified as Gross type D. Though Gross type C was suspected preoperatively, the proximal fistula was found coincidentally during the preparation of the upper pouch. Because, for one thing, the origin of the proximal fistula was close to the end of the upper pouch (1cm), and for another, the distance between the both fistulae was short (1cm). As for the proximal fistula, it was 2 mm in diameter, and it was easily sealed with the side of the endotracheal tube. No other respiratory managements were needed except frequent suctionings of copious intratracheal secretions. On the other hand, the distal fistula, 10 mm in diameter, caused hypercapnea due to hypoventilation before gastrostomy. It was so big that it is easily intubated. This type of tracheoesophageal fistula is extraordinarily rare and its proximal fistula is difficult to find before, during, and even after operation. The missing of the proximal fistula often provokes severe respiratory infections and furthermore, sepsis postoperatively. It is concluded that in all the cases of tracheoesophageal fistula, the existence of the proximal fistula should be considered without fail and managed accordingly. To diagnose correctly, the use of preoperative bronchofiberscopy is also recommended.

Anesthesia↗
PubMed1992

[Serum catecholamine concentrations and hemodynamics during operations on 23 children with neuroblastoma].

The purpose of the present report is to reveal the relation between hemodynamic changes and serum catecholamine concentrations during operation of 23 neuroblastoma patients. The patients were aged from 6 months to 7 years (mean 1.2 year), and 20 patients (86%) were under 1 year of age. All the patients were in early stage of tumor development because they were diagnosed as neuroblastoma mainly by mass screening test for VMA and HVA in urine utilizing HPLC. This urinary mass screening test for infants is performed routinely in Japan. Operative manipulation of tumor provoked the significant elevation of blood pressure, and the increasing tendency of heart rate and rectal temperature. The mean concentrations of three kinds of serum catecholamine, epinephrine, norepinephrine and dopamine, were all very high during manipulation of tumor. Especially, the norepinephrine concentration was 90.2 times higher than the preoperative value. The children who showed high blood pressure, over 70% of the control level, showed high urinary VMA and VMA/HVA ratio preoperatively and a high norepinephrine secretion during operation. We conclude that for the anesthetic management of neuroblastoma, it is necessary to control the elevation of blood pressure even in small children, especially in the patients who have showed high values of urinary VMA and VMA/HVA ratio preoperatively.

Child↗
PubMed1991

[The severity of dementia and brainstem auditory evoked potentials--peak latency and interpeak latency].

We have examined the correlation of dementia severity and brainstem auditory evoked potentials. The subjects were 80 patients with dementia (20 males, 60 females) whose mean age was 80.7 years. Normal controls were 9 elderly subjects (2 males, 7 females) whose mean age was 80.4 years. The following parameters were measured: peak latencies (I, III and V), interpeak latencies (I-III, III-V and I-V) and interaural latency differences (V PLDs and I-V IPLDs). As for clinical items and sex differences; (1) There were sex differences recognized between peak latency of III and V, interpeak latency of III-V and I-V. (2) There was a significant difference in interaural differences of V PL Ds between vascular dementia and degenerative dementia (dementia of the Alzheimer's type and Parkinson's disease). Duration of illness had no correlation with latencies of BAEPs. Dividing the patients into three groups according to the severity of dementia which are mild, moderate and severe, (3) peak latency of III, V and interpeak latency of I-III, III-V, I-V and interaural latency differences of V PL Ds prolonged significantly with the increasing severity of dementia. From these results, it is suggested that brainstem dysfunction progresses with the increasing severity of the dementia.

Aged↗
PubMed1990

Population study on the adipose tissue distribution in Japanese women born in 1948.

We examined the relationship between body fat distribution and glucose metabolism and sex hormones in Japanese premenopausal women born in 1948. 1. There was a significant positive correlation shown between the waist circumference or skinfolds of the upper body, and the fasting insulin and C-peptide levels. 2. A positive correlation was seen between W2-3/H, and both insulin (r = 0.29, 0.30, P less than 0.05) and C-peptide levels (r = 0.40, 0.33, P less than 0.01, 0.05). 3. A significant negative correlation was seen between the SHBG level, and BMI (r = -0.39, p less than 0.01), W3/H (r = -0.46, P, 0.01), insulin (r = -0.28, P less than 0.05), and C-peptide (r = -0.46, P less than 0.01). 4. A significant negative correlation was seen between SHBG and W3/H (r = -0.31, P less than 0.05) after adjustment for BMI. These results suggest that the association of body fat distribution and glucose metabolism and androgeneity even if taking account of BMI, exists in non-obese women.

Adipose Tissue↗
PubMed1990

Adverse effects of obesity on lipid and lipoprotein levels in the patients with non-insulin dependent diabetes in the young.

We studied the association of obesity with serum lipid and lipoprotein concentrations in 117 patients (62 males and 55 females) with NIDDY and in 40 nondiabetic control subjects (21 males and 19 females). Obesity at a young age was related to increased lipid and lipoprotein levels both in the patients with NIDDM and the control group. Moreover, low HDL-c levels were aggravated by diabetic status only in males. The BMI and fasting insulin level had a statistically significant correlation with the TG and HDL-c level and various atherogenic factors. Therefore, it is suggested that the lipid abnormalities seen in obesity may be associated with hyperinsulinemia. We conclude that obesity in adolescence leads to aberrations of the serum lipid and lipoprotein levels, particularly in obese males with NIDDY.

Adolescent↗