Large-scale cDNA analysis of the maternal genetic information in the egg of Halocynthia roretzi for a gene expression catalog of ascidian development

The ascidian egg is a well-known mosaic egg. In order to investigate the molecular nature of the maternal genetic information stored in the egg, we have prepared cDNAs from the mRNAs in the fertilized eggs of the ascidian, Halocynthia roretzi. The cDNAs of the ascidian embryo were sequenced, and the localization of individual mRNA was examined in staged embryos by whole-mount in situ hybridization. The data obtained were stored in the database MAGEST (http://www.genome.ad.jp/magest) and further analyzed. A total of 4240 cDNA clones were found to represent 2221 gene transcripts, including at least 934 different protein-coding sequences. The mRNA population of the egg consisted of a low prevalence, high complexity sequence set. The majority of the clones were of the rare sequence class, and of these, 42% of the clones showed significant matches with known peptides, mainly consisting of proteins with housekeeping functions such as metabolism and cell division. In addition, we found cDNAs encoding components involved in different signal transduction pathways and cDNAs encoding nucleotide-binding proteins. Large-scale analyses of the distribution of the RNA corresponding to each cDNA in the eight-cell, 110-cell and early tailbud embryos were simultaneously carried out. These analyses revealed that a small fraction of the maternal RNAs were localized in the eight-cell embryo, and that 7.9% of the clones were exclusively maternal, while 40.6% of the maternal clones showed expression in the later stages. This study provides global insights about the genes expressed during early development.

Two new drainage tubes for minimally invasive cardiac surgery

BACKGROUND

The limited exposure typical of new minimally invasive surgical approaches to cardiac surgery makes it difficult to utilize traditional equipment such as temporary pacing electrodes or the placement of drainage tubes into the lateral pleural space. To overcome these difficulties, we have developed specialized drainage tubes just for limited access cardiac surgery.

METHODS

The first device is a drainage tube with temporary pacing function. It has three fixed electrodes and one free pacing wire incorporated into an elliptical, angled 28 Fr silicone drainage tube. This tube is placed in the space between the heart and the diaphragm. The two fixed electrodes provide epicardial contact for ventricular pacing. The third fixed electrode and one free pacing wire are for the purpose of atrial pacing (Japanese patent #2,701,135). The second device is a Y-shaped drainage tube. Frequently, the pleural space is opened during harvesting of an internal mammary graft and then insertion of a chest tube in the thoracic cavity becomes necessary. We developed a new Y-shaped tube where one segment is placed in the retrosternal space and one segment is placed in the pleural cavity. (Japanese Association of Intellectual Copyright #130,591)

RESULTS

The drainage-pacing device was used in 48 coronary artery bypass grafting (CABG) patients. Drainage function and pacing function were excellent in all patients. The bifurcated drainage device was used in 34 patients achieving effective drainage of both cavities without complication during or after removal.

CONCLUSIONS

Due to the limited surgical exposure provided by the newer minimally invasive procedures in cardiac surgery, specialized equipment that can be inserted through small incisions needs to be developed. We report the development of a new drainage-pacing device as well as a bifurcated drain for simultaneous drainage of the mediastinal and pleural cavities. These devices have facilitated minimally invasive cases and were free of complications.

Nuclear plasticity and timing mechanisms of the initiation of alkaline phosphatase expression in cytoplasm-transferred blastomeres of ascidians

Egg cytoplasm containing endoderm determinants was transferred to presumptive-muscle or presumptive-epidermis blastomeres isolated from cleavage-stage embryos of the ascidian Halocynthia roretzi. We investigated three aspects of the expression of endoderm-specific alkaline phosphatase (ALP) activity. First, we examined whether ectopic ALP expression, an indication of ectopic endoderm formation, was promoted in cytoplasm-transferred blastomeres isolated at late-cleavage stage. The results showed that the cell fate was converted by the introduced cytoplasm, even in recipient blastomeres in which the cell fate was already restricted to muscle or epidermis, and in those where expression of the muscle- or epidermis-specific genes was already initiated. Next, we examined the formation of endoderm and other tissue in embryos by double staining for ALP and muscle- or epidermis-specific marker. Regions positive for ALP and positive for muscle or epidermis marker were mutually exclusive. These results suggested that muscle- or epidermis-specific genes that were already expressed in the recipient blastomeres were down-regulated in ectopically forming endoderm cells. This is evidence for nuclear plasticity during ascidian embryogenesis. In the last series of experiments, we investigated the timing of the appearance of ALP activity in cytoplasm-transferred embryos. In the partial embryos that were derived from various combination of recipient blastomeres and donor cytoplasm obtained from various staged eggs and embryos, the timing seemed to coincide with the time that starts when cell fusion for cytoplasmic transfer was done. Therefore, the clock that determines the timing of the initiation of ALP expression is likely to start at the moment of cell fusion. Several possible hypotheses for the timing mechanism are discussed.

Sextuple coronary artery bypass grafting using only in situ arterial conduits

Sequential bypass in coronary artery bypass grafting with in situ arterial conduits, the bilateral internal thoracic arteries and the right gastroepiploic artery, is one of the most important procedures using a limited number of in situ arterial conduits to revascularize a wide area, although it demands rather difficult techniques. We report a case of a 50-year-old man who underwent sextuple bypass using only in situ arterial grafts with three sequential anastomoses.

Binary specification of nerve cord and notochord cell fates in ascidian embryos

In the ascidian embryo, the nerve cord and notochord of the tail of tadpole larvae originate from the precursor blastomeres for both tissues in the 32-cell-stage embryo. Each fate is separated into two daughter blastomeres at the next cleavage. We have examined mechanisms that are responsible for nerve cord and notochord specification through experiments involving blastomere isolation, cell dissociation, and treatment with basic fibroblast growth factor (bFGF) and inhibitors for the mitogen-activated protein kinase (MAPK) cascade. It has been shown that inductive cell interaction at the 32-cell stage is required for notochord formation. Our results show that the nerve cord fate is determined autonomously without any cell interaction. Presumptive notochord blastomeres also assume a nerve cord fate when they are isolated before induction is completed. By contrast, not only presumptive notochord blastomeres but also presumptive nerve cord blastomeres forsake their default nerve cord fate and choose the notochord fate when they are treated with bFGF. When the FGF-Ras-MAPK signaling cascade is inhibited, both blastomeres choose the default nerve cord pathway, supporting the results of blastomere isolation. Thus, binary choice of alternative fates and asymmetric division are involved in this nerve cord/notochord fate determination system, mediated by FGF signaling.

Reconstruction of the left ventricle in a patient with cardiac hemangioma at the apex

Cardiac hemangiomas in the left ventricle are extremely rare. A 34-year-old woman, without symptoms, with a diagnosis of cardiac tumor at the apex of the left ventricle was referred to us. The tumor was surgically resected, and the diagnosis was hemangioma. The Jatene technique, originally introduced for left ventricular aneurysmectomy was excellent for repair after resection of a cardiac tumor at the apex.

[Postoperative rupture of abdominal aortic aneurysm in patients with ischemic heart disease and other organ disease]

We experienced two cases of rupture of an abdominal aortic aneurysm during the early postoperative period of coronary artery bypass grafting (CABG). A 71-year-old man on hemodialysis (HD) was diagnosed with ischemic heart disease (IHD) and abdominal aortic aneurysm (AAA) of 70 mm in size. After CABG, he developed symptoms of acute pancreatitis and died of rupture of AAA on the 12th postoperative day. A 74-year-old man with early gastric cancer was diagnosed with IHD and AAA of 70 mm. After CABG and gastrectomy, he died of rupture of AAA due to anticoagulant therapy on the 3rd postoperative day. One-stage operation should be performed in patients with IHD, AAA more than 60 mm in size and other organ disease. It is important to control blood pressure and anticoagulant therapy appropriately during the early postoperative period when graft replacement for AAA is not performed simultaneously. Careful observation is required to establish the differential diagnosis of acute pancreatitis and impending rupture of AAA in patients on HD.

Coronary artery bypass grafting in 105 patients with hemodialysis-dependent renal failure

This study was proposed to define early and long-term results of coronary artery bypass grafting (CABG) in dialysis-dependent renal failure (RF) patients, and preoperative patient characteristics. This study included 105 patients (87 males and 18 females; mean age 60.0 +/- 9.0 years, range 39-79) with RF on maintenance dialysis (hemodialysis 100, peritoneal dialysis 5) who underwent isolated CABG between August 1985 and April 2000. Postoperative follow-up was completed in 100% and averaged 3.1 years. There were 22 emergency and 2 re-CABG cases. Previous myocardial infarction (MI) was found in 55 patients (52%), and unstable angina was noted in 53 patients (50%). Diabetes mellitus was the cause of RF in 50 patients (48%; 24 patients required insulin). There was 1 case of single vessel disease, 31 cases of double vessel disease, 54 cases of triple vessel disease, and 19 cases of left main disease. Preoperative left ventriculography was performed in 92 patients (88%). Left ventricular ejection fraction (LVEF) was 48.3 +/- 15.8% (range 11-74%) and was 40% or less in 25 patients (27%). The mean number of distal anastomoses was 2.5 (range 1-5). Three patients received only vein grafts, but all were cases of emergency CABG. The remaining 102 patients (97%) received at least 1 arterial conduit. Among them, 64 patients received only arterial conduits, and 72 patients received 2 or more distal anastomoses with arterial conduits. Five patients (4.8%) died within 30 days after CABG (2 cardiac deaths and 3 noncardiac deaths), and 8 patients (7.6%) died beyond 30 days after CABG before discharge (all noncardiac deaths). The cause of 2 cardiac deaths was abrupt circulatory collapse during or after hemodialysis in patients with severe left ventricular dysfunction (LVEF; 11% and 28%) in the early postoperative period. The causes of 8 noncardiac deaths included infection in 4 and rupture of aortic aneurysm, stroke, sleep apnea syndrome, and mesenteric infarction. During the follow-up period, there were 29 late deaths (8 cardiac, 13 noncardiac, and 8 sudden death), 6 MIs, 13 percutaneous transluminal coronary angioplasty, and 1 re-CABG. The 5-year actuarial survival rate was 59.8%, the cardiac death-free rate was 83.0%, and the cardiac event-free rate was 62.4%. Although CABG in patients on hemodialysis is associated with high early and long-term mortality in terms of both cardiac and noncardiac deaths in proportion to the severity of the preoperative condition, long-term survival was still better than that of general dialysis patients. Meticulous perioperative management may be the key factor in the improvement of early results.

International Child Care Practices Study: infant sleeping environment

BACKGROUND

The International Child Care Practices Study (ICCPS) has collected descriptive data from 21 centres in 17 countries. In this report, data are presented on the infant sleeping environment with the main focus being sudden infant death syndrome (SIDS) risk factors (bedsharing and infant using a pillow) and protective factors (infant sharing a room with adult) that are not yet well established in the literature.

METHODS

Using a standardised protocol, parents of infants were surveyed at birth by interview and at 3 months of age mainly by postal questionnaire. Centres were grouped according to geographic location. Also indicated was the level of SIDS awareness in the community, i.e. whether any campaigns or messages to "reduce the risks of SIDS" were available at the time of the survey.

RESULTS

Birth interview data were available for 5488 individual families and 4656 (85%) returned questionnaires at 3 months. Rates of bedsharing varied considerably (2-88%) and it appeared to be more common in the samples with a lower awareness of SIDS, but not necessarily a high SIDS rate. Countries with higher rates of bedsharing appeared to have a greater proportion of infants bedsharing for a longer duration (>5 h). Rates of room sharing varied (58-100%) with some of the lowest rates noted in centres with a higher awareness of SIDS. Rates of pillow use ranged from 4% to 95%.

CONCLUSIONS

It is likely that methods of bedsharing differ cross-culturally, and although further details were sought on different bedsharing practices, it was not possible to build up a composite picture of "typical" bedsharing practices in these different communities. These data highlight interesting patterns in child care in these diverse populations. Although these results should not be used to imply that any particular child care practice either increases or decreases the risk of SIDS, these findings should help to inject caution into the process of developing SIDS prevention campaigns for non-Western cultures.

Effects of different durations of exercise on macrophage functions in mice

The effects of differing durations of daily exercise on macrophage functions in mice were studied. Male ICR mice aged 4 wk were divided into five groups: a nonexercise group (control) and four exercise groups with differing daily exercise durations of 15--120 min (Exr groups). The exercise applied was 5 days/wk treadmill running at 13 m/min for 12 wk. The potentiation of the phagocytosis function of the reticuloendothelial system and the glucose consumption of peritoneal macrophages in the Exr 30, 60, and 120 groups were significantly higher than those in the control group. Superoxide anion production of peritoneal macrophages in both the absence and the presence of phorbol 12-myristate 13-acetate in the Exr 60 and 120 groups was significantly higher than that in the control group. The acid phosphatase and beta-glucuronidase activities of peritoneal macrophages in the Exr 30, 60, and 120 groups were significantly increased. These results suggest that treadmill running exercise for at least 30 min/day (30--120 min) effectively enhances macrophage functions in mice. These data provide preliminary evidence indicating that chronic exercise-induced increases in phagocytic activity exhibit a dose-dependent relationship with exercise duration.

macho-1 encodes a localized mRNA in ascidian eggs that specifies muscle fate during embryogenesis

Maternal information stored in particular regions of the egg cytoplasm has an important function in the determination of developmental fate during early animal development. Ascidians show mosaic development; such autonomous development has been taken as evidence that prelocalized ooplasmic factors specify tissue precursor cells during embryogenesis. Interest has been concentrated on the mechanisms underlying the formation of muscle cells in the tail, as yellow-coloured myoplasm in eggs is preferentially segregated into muscle-lineage blastomeres. Here we show that maternal messenger RNA of the macho-1 gene is a determinant of muscle fate in the ascidian Halocynthia roretzi. The macho-1 mRNA encodes a zinc-finger protein, and the mRNA is localized to the myoplasm of eggs. Depletion of the mRNA specifically resulted in the loss of primary muscle cells in the tail, as shown by the expression of muscle-specific molecular markers. The myoplasm of macho-1-deficient eggs lost its ability to promote muscle formation. Injection of synthesized macho-1 mRNA caused ectopic muscle formation in non-muscle-lineage cells. Our results indicate that macho-1 maybe both required and sufficient for specification of muscle fate, and that the mRNA is a genuine, localized muscle determinant.

Distribution of genes for lysine biosynthesis through the aminoadipate pathway among prokaryotic genomes

Deinococcus radioduranshas homologous genes to the genes which from the Thermus: thermophilus gene cluster for lysine biosynthesis. Interestingly, those genes are clustered in Thermus, nevertheless they are scattered in Deinococcus. A similar gene cluster has only been found in Pyrococcus However, the phylogenetic analyses indicated that the deduced gene products from Deinococcus were the most closely related to the proteins encoded in the Thermus gene cluster for lysine biosynthesis. Therefore, those genes had not been transferred horizontally between Pyrococcus and Thermus. It is strongly suggested that a common ancestor of Deinococcus and Thermus possessed the genes for lysine biosynthesis through the aminoadipate pathway. These had been clustered through the evolution of Thermus or had been scattered from the gene cluster through the evolution of Deinococcus. In addition, I showed that LysW and its homologues were specialized proteins for the prokaryotic lysine biosynthesis through the aminoadipate pathway.

Prognostic value of the colposcopic tumor size in stage IB squamous cervical cancer

BACKGROUND AND OBJECTIVES

To determine the prognostic significance of the colposcopic tumor size in the management of cervical cancer.

METHODS

Clinicopathological analysis was performed in 751 consecutive patients with stage IB squamous cervical cancer who were surgically treated in a single institute. The colposcopic tumor size was measured postoperatively on surgical specimens. Univariate and multivariate analyses were performed to determine the prognostic significance of various pathological factors.

RESULTS

Among the pathological factors examined, lymph node metastasis, parametrial extension, deep stromal invasion, vessel permeation, endometrial extension, and colposcopic tumor size were found to be prognostic factors in univariate analysis, whereas multivariate analysis has confirmed that only three factors, i.e., lymph node metastasis, parametrial involvement, and colposcopic tumor size were independently associated with the disease-free interval.

CONCLUSIONS

These results indicate that the colposcopic tumor size is an independent prognostic factor in squamous cervical cancer and can be used as an indicator of treatment options.

Off-Pump Reimplantation of Anomalous Origin of the Right Coronary Artery

A 30-year-old man was diagnosed to have an anomalous origin of the right coronary from the pulmonary artery. Through a mini-sternotomy, without extracorporeal circulation, reimplantation of the anomalous origin of the right coronary artery from the pulmonary artery to the aorta was successfully performed. This is a successful case of off-pump cardiac correction of this type of isolated anomaly, using a minimally invasive approach.

Immunopathophysiological aspects of an emerging neonatal infectious disease induced by a bacterial superantigen

We recently discovered an emerging neonatal infectious disease, neonatal toxic shock syndrome-like (TSS-like) exanthematous disease (NTED), which is induced by a superantigen, TSS toxin-1 (TSST-1), produced by methicillin-resistant Staphylococcus aureus (MRSA). Here, we analyzed the activation and the response of TSST-1-reactive Vss2(+) T cells in NTED patients during the acute and recovery phases and in asymptomatic infants exposed to MRSA. In the acute phase, Vss2(+) T cells were anergic to stimulation with TSST-1 and underwent marked expansion, but by 2 months after disease onset, their numbers had declined to about 10% of the control level. Although the percentage of Vss2(+) T cells in the ten asymptomatic neonatal MRSA carriers was within the control range, these individuals could be divided into two groups on the basis of Vss2(+) T-cell activation. Vss2(+)CD4(+) T cells from three of these infants (Group 1) highly expressed CD45RO and were anergic to TSST-1, whereas in the other seven asymptomatic neonatal MRSA carriers (Group 2), these cells expressed CD45RO at the control level and were highly responsive to stimulation with TSST-1. The serum anti-TSST-1 IgG Ab titer was negligible in the four NTED patients in the acute phase and the three asymptomatic neonatal MRSA carriers in Group 1, but it was high in the seven asymptomatic carriers in Group 2. We suggest that maternally derived anti-TSST-1 IgGs helps to suppress T-cell activation by TSST-1 and protects infants from developing NTED.

Length and quality of survival following external beam radiotherapy combined with expandable metallic stent for unresectable hilar cholangiocarcinoma

BACKGROUND AND OBJECTIVES

Hilar cholangiocarcinoma is a morbid disease with a poor prognosis because resection cannot be performed in many cases. The purpose of this study was to evaluate whether external beam radiotherapy (RT) combined with expandable metallic biliary stent (EMS) affects the length and quality of survival of patients with unresectable hilar cholangiocarcinomas.

METHODS

Fifty-one patients with unresectable hilar cholangiocarcinoma were retrospectively reviewed. Thirty patients received external beam radiotherapy combined with EMS (EMS+RT group), 10 patients were treated with EMS alone (EMS group), and the remaining 11 patients underwent percutaneous transhepatic biliary drainage alone (PTBD group). The length and quality of survival were analyzed and compared among the three groups.

RESULTS

The mean survival of 6.4 months in the EMS group was significantly longer than that of 4.4 months in the PTBD group (P < 0.05). The EMS+RT group with a mean survival of 10.6 months had a significantly longer survival than the EMS group (P < 0.05). The average of the monthly Karnofsky scores of 74.9 in the EMS+RT group and 68.1 in the EMS group, as a parameter of quality of survival, was significantly higher than that of 57.7 in the PTBD group (P < 0.01). The number of hospital days per month of survival was significantly smaller in the EMS+RT and EMS groups than in the PTBD group (10.4, 14.2 vs. 27.3 days; P < 0.001). The EMS+RT group had a longer stent patency than the EMS group (mean: 9.8 vs. 3.7 months; P < 0.001).

CONCLUSIONS

These results indicate that external radiotherapy combined with metallic biliary endoprosthesis can increase the length and quality of survival and consequently provide a definite palliative benefit for patients with unresectable hilar cholangiocarcinoma.

Localization of parathyroid glands in hemodialysis patients using Tc-99m sestamibi imaging

Tc-99m sestamibi parathyroid imaging was performed in 28 patients with chronic renal failure to localize abnormal parathyroid glands in patients receiving hemodialysis, and compared the localization with ultrasonography and magnetic resonance (MR) imaging.

METHODS

We imaged 28 patients with secondary hyperparathyroidism using Tc-99m sestamibi (about 600 MBq) at 10 min and 2-3 h following radiotracer injection. In addition, mediastinal images were recorded at approximately 1 h following injection to identify ectopic parathyroid glands. All patients also were evaluated with ultrasonography and MR imaging.

RESULTS

Tc-99m sestamibi scans demonstrated focal uptake in 60 glands of the 28 patients, and was categorized as slight uptake in 71.7% (43/60), and intense uptake in 28.3% (17/60). Seventeen of the 28 patients underwent parathyroidectomy. A total of 64 glands were resected. Sestamibi imaging was more sensitive for localizing abnormal parathyroid glands than ultrasonography or MR imaging. Histologic evaluation of 27 resected parathyroid glands revealed that the number of oxyphil or chief cells was not proportional to sestamibi uptake.

CONCLUSION

Our data indicate that Tc-99m sestamibi imaging should be used initially to localize abnormal parathyroid glands in hemodialysis patients with secondary hyperparathyroidism, prior to MR imaging or ultrasonography. Sestamibi uptake in parathyroid glands may not correlate with the degree of hypercellularity of oxyphil cells.

Length and quality of survival following external beam radiotherapy combined with expandable metallic stent for unresectable hilar cholangiocarcinoma

BACKGROUND AND OBJECTIVES

Hilar cholangiocarcinoma is a morbid disease with a poor prognosis because resection cannot be performed in many cases. The purpose of this study was to evaluate whether external beam radiotherapy (RT) combined with expandable metallic biliary stent (EMS) affects the length and quality of survival of patients with unresectable hilar cholangiocarcinomas.

METHODS

Fifty-one patients with unresectable hilar cholangiocarcinoma were retrospectively reviewed. Thirty patients received external beam radiotherapy combined with EMS (EMS+RT group), 10 patients were treated with EMS alone (EMS group), and the remaining 11 patients underwent percutaneous transhepatic biliary drainage alone (PTBD group). The length and quality of survival were analyzed and compared among the three groups.

RESULTS

The mean survival of 6.4 months in the EMS group was significantly longer than that of 4.4 months in the PTBD group (P < 0.05). The EMS+RT group with a mean survival of 10.6 months had a significantly longer survival than the EMS group (P < 0.05). The average of the monthly Karnofsky scores of 74.9 in the EMS+RT group and 68.1 in the EMS group, as a parameter of quality of survival, was significantly higher than that of 57.7 in the PTBD group (P < 0.01). The number of hospital days per month of survival was significantly smaller in the EMS+RT and EMS groups than in the PTBD group (10.4, 14.2 vs. 27.3 days; P < 0.001). The EMS+RT group had a longer stent patency than the EMS group (mean: 9.8 vs. 3.7 months; P < 0.001).

CONCLUSIONS

These results indicate that external radiotherapy combined with metallic biliary endoprosthesis can increase the length and quality of survival and consequently provide a definite palliative benefit for patients with unresectable hilar cholangiocarcinoma.

Case-control study of perinatal factors and hepatoblastoma in children with an extremely low birthweight

BACKGROUND

There is a significant association between hepatoblastoma and low birthweight. A case-control study was conducted to reveal risk factors for hepatoblastoma in children of extremely low birthweight (< 1,000 g).

METHODS

Prenatal and postnatal histories, including parental histories, of 12 hepatoblastoma cases and 75 birthweight-matched controls were compared.

RESULTS

The gestational age of the hepatoblastoma cases (23-32 weeks: median 25 weeks), tended to be lower than that of the controls (23-36 weeks; median, 27 weeks; P = 0.072). The time for an infant's bodyweight to return to the same level as the birthweight also tended to be longer in hepatoblastoma cases than in controls (P = 0.055). All hepatoblastoma cases received oxygen therapy for a period of 4-508 days (median 114 days), which was significantly longer than the 0-366 days (median 62 days) in the controls (P = 0.022). Furosemide was given to all hepatoblastoma cases and was used for a significantly longer period in these infants (6460 days; median 89 days) than in the controls (0-241 days; median 44 days P = 0.027). A univariate Cox regression demonstrated that the time taken to regain bodyweight at birth and the duration of both oxygen therapy and furosemide treatment were significantly associated with the development of hepatoblastoma (hazard ratio (HR)= 1.044, P= 0.013; HR = 1.006, P= 0.001; and HR = 1.007, P= 0.001, respectively). Although there were significant correlations between the factors, a multivariate Cox regression analysis identified the duration of oxygen therapy as a significant independent risk factor (HR = 1.006, P = 0.001).

CONCLUSIONS

Oxygen therapy and furosemide treatment, along with the rate of growth, are risk factors for the development of hepatoblastoma in children of extremely low birthweight, and the duration of oxygen therapy is the most important factor in predicting the development of hepatoblastoma. Further studies are necessary to determine the real reasons for the development of hepatoblastoma and to protect children of low birthweight from the development of cancer.

What is characteristic of fungal lysine synthesis through the alpha-aminoadipate pathway?

Recent finding that a prokaryote synthesizes lysine through the alpha-aminoadipate pathway demonstrates that the lysine synthesis through the alpha-aminoadipate pathway is not typical of fungi. However, the fungal lysine biosynthesis is not completely the same as the prokaryotic one. We point out that alpha-aminoadipate reductase is a key enzyme to the evolution of fungal lysine synthesis. In addition, fungi have two different saccharopine dehydrogenases, which is also characteristic of fungi.

Symbiobacterium thermophilum gen. nov., sp. nov., a symbiotic thermophile that depends on co-culture with a Bacillus strain for growth

A Gram-negative and tryptophanase-positive thermophile, whose growth is dependent on co-culture with an associating Bacillus strain, had been reported and tentatively named Symbiobacterium thermophilum strain T(T). Axenic culture of strain T(T) was recently established by dialysing cultures with the supporting bacterial strains or adding their culture broth. Phylogenetic analysis of strain T(T), based on the 16S rDNA sequence, was conducted for the validation of S. thermophilum. The sequence of strain T(T) was located at the outermost position in the high-G+C Gram-positive group distinctly isolated from any other branches hitherto known. Ten sequences identical to that of strain T(T), and one sequence closely related to it, were identified for the first time from soil and compost samples. The outer membrane of strain T(T) had a three-layered structure, outside the cytoplasmic membrane, which is similar to the S-layer in the cells of members of the Bacillaceae. Chemical analysis of the cells revealed that menaquinone-6 is a major component of the quinone system. According to these results, along with several previous observations (i.e. a G+C DNA content of 65 mol% and the identification of iso-C15:0 and iso-C17:0 acids as major cellular fatty acids), the new taxon Symbiobacterium thermophilum gen. nov., sp. nov. is proposed. The type strain is S. thermophilum strain T(T) (= IAM 14863T).

Perinatal and infant outcome of pregnant patients undergoing chronic hemodialysis

Recently, perinatal outcome in patients undergoing chronic hemodialysis has been improved. But the conditions that will most likely result in successful pregnancy are still obscure. We retrospectively analyzed 15 pregnant patients who were undergoing chronic hemodialysis before pregnancy treated in our perinatal center. We divided these 15 cases into 2 groups: one group of 11 patients whose infants survived and the other group of 4 patients whose infants died 6 h to 8 months after birth due to prematurity. The rate of successful pregnancies having a surviving infant was 73.3% (11/15). We compared the maternal conditions and the progress of pregnancy in the 2 groups. Significant differences (p<0.01) were seen as follows. The patients in the group whose infants survived underwent hemodialysis for a shorter term before pregnancy (1-6 years), most of them (9/11) could produce urine (> or =50 ml/day), and the period of gestation was extended (33.3+/-4.7 weeks), so the infants were heavier (1,782.9+/-678.3 g). All the patients who underwent more than 9 years of hemodialysis could not have a surviving infant. From this we can assume that the shorter the period of dialysis before pregnancy, the better the condition is that is likely to result in women giving birth and the better is their infant's chance of survival.