HLA genotyping of 5,000- and 6,000-year-old ancient bones in Japan

We used polymerase chain reaction (PCR)-based DNA typing to identify HLA class II alleles of two individuals from ancient human remains. Genomic DNAs were isolated from two ancient human skeletons excavated from the Sanganji and Kitakogane sites in the main and northern islands of Japan, respectively. They were archaeologically estimated to be approximately 5,000 and 6,000 years old respectively, representing the remnants from the Jomon era. High molecular weight DNA was extracted by the standard proteinase K-phenol extraction method followed by purification with a Centricon-30 micro concentrator. Several rounds of PCR successfully gave rise to amplification of the HLA-DRB1 and -DQA1 genes. The PCR-restriction fragment length polymorphism (PCR-RFLP) and sequencing based typing (PCR-SBT) methods revealed that those ancient individuals possessed the DRB1 and DQA1 alleles which are highly prevalent among the modern north Asian as well as Japanese populations.

A novel negative regulator molecule, Cho-1, is involved in the cytotoxicity by human natural killer cells but not in cytotoxic T lymphocytes

We previously reported the cytotoxic negative regulatory molecule, Cho-1, that was expressed on the cell surface of rat fetal fibroblast cells in the cytotoxicity by natural killer (NK) cells. This molecule was IFN-gamma-inducible, but appeared to be different from MHC class I. It was expressed on NK-resistant cells but not on NK-sensitive murine target cells such as YAC-1. In this paper, first we determined whether Cho-1 could also act as the negative regulatory molecule in a human NK-resistant HEPM line. Our data strongly suggested that Cho-1 could act as such a negative regulatory molecule in human NK cytotoxicity. The immunoprecipitates made with HEPM cell lysate and anti-MHC class I monoclonal antibody (mAb) did not react against anti-Cho-1 mAb, indicating that Cho-I was different from MHC class I. Second, an assessment was made as to whether or not this molecule is involved in the cytotoxicity of CD8 (+) cytotoxic T lymphocytes (CTL) against human autologous tumor cells. The data indicated that although this cell surface molecule was expressed on certain tumor lines, it was not involved in the cytotoxic mechanism of CTL. Thus, Cho-1 appeared to be the novel regulatory molecule in the NK cytotoxic mechanism.

A double bifurcated graft for abdominal aorta and bilateral iliac artery reconstruction

Revascularization of the hypogastric artery often tends to be neglected in aortoiliac reconstructive surgery; however, its incomplete revascularization can result in unfavorable complications such as buttock claudication or necrosis, vascular impotence, and colonic ischemia. Multiple vascular lesions in the abdominal aorta and bilateral iliac arteries were reconstructed using a newly designed double bifurcated graft in five male patients. All five patients demonstrated excellent graft limb patency and postoperative improvement of the ankle-brachial pressure index without any clinical signs of ischemia in regions of the hypogastric artery. Thus, we conclude that an aggressive approach toward hypogastric circulation maintenance is essential in aortoiliac reconstructive surgery. By using this double bifurcated graft, rapid and safe revascularization of the bilateral hypogastric arteries concomitant with the external iliac or femoral arteries can be performed.

Angle-adjustable sheath for a dual-stage venous cannula

The dual-stage venous cannula is widely used but can obstruct the surgeon's view and interfere with operative procedures in the aortic root. We designed a new stainless steel sheath for a dual-stage venous cannula that enables the cannula to bend and maintain the appropriate angle for the surgical procedures. We suggest that operative procedures in the aortic root can be performed faster during safety cardiopulmonary bypass by use of a dual-stage venous cannula bent by application of this new sheath.

Cardiopulmonary bypass established via a sutured vascular graft in the presence of extraanatomic bypass

Cardiopulmonary bypass (CPB) was established via a sutured collagen sealed knitted Dacron graft in two patients who had undergone extraanatomic bypasses for lower limb ischemia, whose ascending aorta was not suitable for cannulation. One patient, with a history of femorofemoral bypass, underwent surgery for a ruptured aortic arch aneurysm (AAA) and the other patient, with a history of axillobifemoral bypass for chronic dissection involving the aortic arch and descending aorta, had unstable angina and underwent coronary artery bypass grafting. This technique of perfusion was found to be safe and effective for patients with an impaired ascending aorta who have undergone an extraanatomic bypass for the lower limb.

A case of ruptured descending thoracic aortic aneurysm into the right pleural cavity: importance of preoperative drainage of the right pleural cavity

We present an unusual case of a ruptured descending thoracic aortic aneurysm into the right pleural cavity of a patient with pectus carinatum. The presence of pectus carinatum played an important role in the development of the aneurysm at the atypical site and the rupture into the right pleural cavity. A small amount of right pleural bleeding on admission can increase and develop to massive hemothorax until emergency operation. Massive bleeding in the right pleural cavity where the dependent lung is located causes atelectasis and increased shunt fraction under one lung ventilation. Therefore, continuous drainage of the right pleural cavity is essential to prevent serious hypoxia during graft replacement in a case of ruptured descending thoracic aneurysm into the right hemithorax.

A modified microsyringe for extracellular recording of neuronal activity

We describe a modified Hamilton microsyringe that allows extracellular recording of neuronal activity and subsequent injections. It is assembled with a Hamilton removable needle and a syringe for injection, a Teflon-coated tungsten wire for recording, and polyimide tubing as a sheath. The device is inexpensive and easy to handle in anatomical and physiological experiments in awake monkeys.

Afterload-dependent flow fluctuation of centrifugal pump: should it be actively fixed?

To evaluate the clinical meaning and effects of afterload-dependent flow fluctuation in a centrifugal pump, concomitant measurement of flow rate and mixed venous oxygen saturation (SVO2) was performed in 5 cases of open heart surgery in which the patients underwent cardiopulmonary bypass (CPB) with the Terumo Capiox centrifugal pump. Continuous measurement of SVO2 using the 3M CDI System 100 was performed with a disposable cuvette incorporated into the drainage circuit. After the target flow rate of 2.4 L/min/m2 was obtained under a nonbeating condition, the pump rotational speed was fixed. During the cooling and low temperature period, SVO2 decreased as the flow rate spontaneously decreased but still stayed around 80% even with a 15-20% decrease in blood flow rate. This indicates that a luxury perfusion condition is ensured as long as the body temperature is kept low. In contrast, during the rewarming period, SVO2 decreased to around 70-75% despite a 15-25% spontaneous increase in flow rate. Although this level of SVO2 still indicates adequate systemic perfusion, there is a possibility of regional hypoperfusion in patients with such conditions as cerebrovascular disease. In conclusion, although diligent adjustment of the physiological fluctuating flow rate in the centrifugal pump seems unnecessary during conventional open heart surgery, manual control may be necessary especially during the rewarming period, normothermic surgery, or circulatory assist for shocked patients. From this study, we also conclude that the major benefit of the afterload-independent autoflow control system of the centrifugal pump is the improvement of safety in terms of the fixed reservoir level and the handling of cardiopulmonary bypass.

[Coronary artery bypass grafting to the left circumflex artery in the atrioventricular groove]

Coronary artery bypass graftings were performed to the left circumflex artery (LCX) system in the atrioventricular groove (#11 or #13) in addition to revascularization to the left anterior descending artery system using conventional technique in 10 patients with left main trunk lesion. Distal anastomosis was done at #11 of LCX in 6 patients using saphenous vein graft, and at #13 of LCX in 4 patients using 2 saphenous vein grafts and using 2 internal thoracic artery grafts. The mean flow rate of SVG operated by this technique showed larger values than that of SVGs by sequential bypass or individual bypass technique to #12 and/or #14 of LCX. Postoperative angiographies showed excellent graft patencies and symptomatic improvements were achieved. This technique of coronary artery revascularization is recommended and useful in patients whose #12 and #14 of LCX system is too small to make distal anastomosis.

Dietary protein as a factor affecting vitamin B6 requirement

Rats were fed 20 or 70% casein diets with varying amounts of vitamin B6 (B6), and the B6 content and B6-dependent enzymatic activity in their tissues were examined to determine the minimum requirement of B6 for animals subjected to different levels of dietary protein (i.e., 20%: 0, 1.45, 2.90, 5.80 mg pyridoxine (PN)/kg diet; 70%: 0, 2.90, 5.80, 8.70 mg PN/kg diet). B6 requirements for the rats were almost met in the 1.45 mg PN/kg 20% casein diet and the 2.90 mg PN/kg 70% casein diet when judged from the hepatic B6 content. However, almost twice the PN was required in both 20 and 70% casein diets when judged from PLP-enzymatic activity. The content of B6 vitamers in plasma appeared to be most sensitive to B6 status, though the satisfactory level is not known. It was confirmed that, in any case tested, a high-protein diet increased the requirement of B6.

[Postoperative complications after coronary bypass operations in patients with pulmonary impairment]

The postoperative courses of 112 patients with pulmonary disease (59 with obstructive disease = Group 0, 38 with restrictive disease = Group R and 15 with mixed disease = Group M) who underwent elective coronary artery bypass grafting were retrospectively reviewed. Preoperative pulmonary function test (percentage of vital capacity = %VC and percentage of forced expiratory volume at 1 second = FEV1.0%) of these group showed typical abnormal values, and velocity ratio of 50% and 25% of maximum expiratory flow volume (V50/V25) of each groups were measured abnormal values (3.99 +/- 1.44 of Group O, 4.26 +/- 1.42 of Group R and 3.74 +/- 1.82 of Group M). The our strategy for these groups were a). Using skeletonization method for harvesting internal mammary artery (IMA) b) Take care not to injure the phrenic nerve and open the pleural cavity as surgical techniques (Harvesting IMA) and c) Administration of theophylline derivatives and corticosteroids to prevent bronchospasm d) Administration of concentrated serum albumin and diuretics to prevent pulmonary edema as therapeutic measures. The length of stay in the intensive care unit and ventilation time of each groups were not significantly longer. Patients of group M had more respiratory complications (atelectasis, pleural effusion, pneumothrax, bronchospasm, and pneumonia) than did patients of group R (p < 0.05), but did not more nonpulmonary complications and hospital deaths. The four in hospital deaths (2 with group O, 1 with group R and 1 with group M) were not directly related to pulmonary complications. Thus, result of CABG in patients with pulmonary impairment definitely proved to be satisfactory by our strategy, but mixed pulmonary diseased significantly had more pulmonary complications.

[Effect of nitrous oxide at sub-MAC concentrations on sevoflurane MAC in adults]

The interaction of sevoflurane and nitrous oxide (N2O) on the MAC was studied in the four groups of patients between 30-60 years of age scheduled for laparotomies. Patients received one of four different concentrations of N2O [0% (n = 14), 25% (n = 16), 50% (n = 15), or 70% (n = 18)]. Anesthesia was induced with sevoflurane and N2O using a semiclosed circuit with a carbon dioxide absorber. After endotracheal intubation, sevoflurane and N2O end-tidal concentrations were adjusted to predetermined concentrations until the skin incision was made. The MAC values for sevoflurane in O2 and the presence of 25%, 50%, and 70% N2O were 1.68%, 1.33%, 0.82% and 0.55%, respectively. A regression analysis through all four data points yielded a linear relationship (r = -0.997). The requirement of sevoflurane decreased by approximately 1% for each 1% of N2O administered at three N2O concentrations. The extrapolated MAC value for N2O was 102%. The MAC values of sevoflurane in O2 and N2O were similar to the previously reported values. We conclude that in adults, N2O concentrations in the dose range 0-70% reduce sevoflurane MAC in a linearly additive manner.

Origin of thalamocortical projections to the presupplementary motor area (pre-SMA) in the macaque monkey

The presupplementary motor area (pre-SMA) is a recently defined cortical motor area that is located immediately rostral to the supplementary motor area (SMA) and is considered to play more complex roles in motor control than the SMA. In the present study, we examined the distribution of cells of origin of thalamocortical projections to the pre-SMA in the macaque monkey. Under the guidance of intracortical microstimulation mapping, the retrograde tracer biotinylated dextran amine was injected into the pre-SMA. Retrogradely labeled neurons were distributed primarily in the parvicellular division of the ventroanterior nucleus (VApc), oral division of the ventrolateral nucleus (VLo), area X, and mediodorsal nucleus (MD). Some labeled neurons were also observed in the medial and caudal divisions of the ventrolateral nucleus. The results indicate that the pre-SMA may receive not only basal ganglia inputs via the VApc, VLo, and MD, but also a cerebellar input via the X.

[A case report on graft replacement of ruptured aneurysm of the arch and the descending thoracic aorta associated with dense pulmonary adhesion]

A 73-year-old patient had been followed for aortic arch aneurysm of 54 mm in diameter. He was hospitalized complaining of chest and back pain. A chest CT scan showed ruptured aortic arch aneurysm extending to mid-descending thoracic aorta, and an emergent operation was decided. The trachea was intubated with a univent tube providing a movable blocker (System Corporation) which was directed to the left bronchus for differential lung ventilation. The descending thoracic aorta was exposed through the left 4th intercostal thoracotomy just at the site intending to anastomose a prosthetic graft because of dense pulmonary adhesion. The ascending and arch aorta was approached via median sternotomy. Under deep hypothermia and retrograde cerebral perfusion, total arch and descending aortic replacement was performed using an arch graft providing four branch grafts for neck vessels reconstruction and pump perfusion. The patient showed moderate pulmonary bleeding during and after cardiopulmonary bypass, but improved gradually. He was weaned from the respirator on the 13th post-operative day. During extensive thoracic aortic surgery using left thoracotomy combined with median sternotomy, left lung deflation using a univent tracheal tube with a blocker, and circulatory arrest during distal aortic anastomosis, are useful in preventing lethal pulmonary bleeding caused by lung injury under the fully heparinized condition. However, in cases associated with dense pulmonary adhesion, it is important to dissect carefully just a small area necessary to anastomose a graft, and to take elaborate assistant measures.

Physicochemical and serological characterization of rice alpha-amylase isoforms and identification of their corresponding genes

We have identified, purified, and characterized 10 alpha-amylase isoforms from suspension-cultured rice (Oryza sativa L.) cells having different isoelectric point values. They had distinguishable optimum temperatures for enzymatic activity and molecular sizes. The results of immunoblotting indicated that polyclonal anti-A + B antibodies bound well to isoforms A, B, Y, and Z but weakly or not at all to E, F, G, H, I, and J. However, the anti-A + B antibodies inhibited the enzyme activities of only isoforms A and B. Polyclonal anti-H antibodies strongly bound to isoforms F, G, H, I, and J, whereas polyclonal anti-E antibodies preferentially recognized isoform E. A monoclonal antibody against isoform H (H-G49) inhibited the activities of isoforms E, G, H, I, and J, whereas it did not inhibit those of isoforms A, B, Y, and Z. Judging from their physicochemical and serological properties, we classified the rice alpha-amylase isoforms into two major classes, class I (A, B, Y, and Z) and class II (E, F, G, H, I, and J), and into four subgroups, group 1 (A and B), group 2 (Y and Z), group 3 (E), and group 4 (F, G, H, I, and J). Partial amino acid sequences for isoforms A, E, G, and H were also determined. In addition, the recombinant alpha-amylases expressed by plasmid pEno/103 containing the rice alpha-amylase gene RAmy1A in yeast were identified as both isoforms A and B. These analyses indicated that isoforms A and B were encoded by the gene RAmy1A, isoforms G and H were encoded by the gene RAmy3D, and isoform E was encoded by RAmy3E. The results strongly suggest that some isoforms within subgroups are formed by posttranslational modifications.

[Incidence of nausea and vomiting after cholecystectomy performed via laparotomy or laparoscopy]

Postoperative nausea and vomiting (PONV) are commonly observed adverse effects of general anesthesia. In a retrospective study of laparoscopy group (101 patient) and laparotomy group (101 patient), we evaluated the incidence of PONV after laparoscopic cholecystectomy. Most factors which could influence the incidence of PONV were not significantly different between the groups. The overall incidence of PONV during the first 17h postoperatively was 25.7% in laparoscopy group and 18.8% for laparotomy group respectively, but the risk was 3.2 times greater in laparoscopy group (15.8%) than in laparotomy group (5.0%) (P < 0.05) during the first postoperative hour. The risk of PONV was greater in laparoscopy group in female patients (23.4% versus 9.3% in laparotomy group, P < 0.05) and in obese patients (25.0% versus 0% in laparotomy group, P < 0.01) during the first postoperative hour. We conclude that laparoscopic cholecystectomy increases the incidence of PONV in early postoperative period probably by the effect of residual stretching and irritation of the peritoneum, and the risk is increased in female and obese patients.

[The effect of clonidine on the duration of vecuronium-induced neuromuscular blockade in humans]

The clinical duration of a bolus of vecuronium 0.1 mg.kg-1 was measured in two groups of patients between 31-55 years of age undergoing elective general surgery. Eight patients received no premedication and eight others clondine 4.0-5.5 micrograms.kg-1 orally 90 minutes before arriving at the operating room. Neuromuscular blockade was continuously quantitated by recording the acceleration response to stimulation of the ulnar nerve train-of-four. Anesthesia was induced with thiamylal 5 mg.kg-1 and maintained with 50% nitrous oxide and isoflurane (Fet 0.5%) in oxygen. Supplementary doses of fentanyl (2 micrograms.kg-1 for the control group and 1 microgram.kg-1 for the clonidine group) were given before intubation and when anesthesia was considered to be insufficient. The clinical duration of vecuronium, defined as recovery to 25% of the control first twitch in the train-of-four sequence, was significantly longer in the clonidine group (51.2 +/- 7.5 minutes compared with 40.5 +/- 5.1 minutes in the control group, P < 0.01). In the duration of blockade there were no significant differences between groups for mean SBP, DBP and HR. Patients in the clonidine group required significantly less fentanyl to maintain hemodynamic stability. We conclude that clonidine prolongs the clinical duration of vecuronium by 26.4%, most probably by a pharmacokinetic interaction.

[The effects of low dose clonidine on perioperative hemodynamics and anesthetic requirements in elderly patients]

The effects of clonidine, alpha 2-adrenergic receptor agonist, on perioperative hemodynamics and anesthetic requirements were studied in randomized 20 elderly patients without hypertension (ASA I-II) scheduled for elective abdominal surgery under general anesthesia. The control group (n = 10) was premedicated with oral diazepam 0.1 mg.kg-1 90 min prior to arrival in the operating room. The clonidine group (n = 10), in addition, received clonidine approximately 2.5 micrograms.kg-1 orally at the same time. Anesthesia was induced with fentanyl 2 micrograms.kg-1 and thiamylal 4 mg.kg-1. Vecuronium 0.15 mg.kg-1 following 0.01 mg.kg-1 priming dose was used to facilitate endotracheal intubation. Anesthesia was maintained with isoflurane in 50% nitrous oxide-oxygen and supplementary fentanyl. Clonidine effectively attenuated the cardiovascular response associated with laryngoscopy and tracheal intubation. Intraoperative variability of heart rate was significantly lower in patients receiving clonidine compared with controls. No significant differences in the requirements of either isoflurane or narcotic supplementation were observed between the two groups. We conclude that a low dose clonidine is a useful adjunct in the management of elderly patients without producing side effects.

Developmental and Hormonal Regulation of Rice [alpha]-Amylase(RAmy1A)-gusA Fusion Genes in Transgenic Rice Seeds

Transgenic seeds of rice (Oryza sativa L.) were used to investigate temporal, spatial, and hormonal regulation of a rice [alpha]-amylase gene, RAmy1A. Two overlapping segments of the RAmy1A promoter were fused to the coding region of the bacterial reporter gene, gusA. The resulting promoter-gusA fusions, pE4/GUS (-232 to +31) and pH4/GUS (-748 to +31), were used separately to transform rice protoplasts. [beta]-Glucuronidase (GUS) activity was detected in germinated transgenic seeds, although the two constructs showed no significant difference in timing or location of GUS expression. Both constructs first expressed GUS in the scutellar epithelium and then in the aleurone layer. Aleurone expression of GUS activity was strongly induced when embryoless half-seeds were treated with gibberellic acid. GUS expression in the aleurone layer was also suppressed by abscisic acid. These results indicate that the 5[prime] regulatory region from -232 to +31 is sufficient for temporal, spatial, and hormonal regulation of RAmy1A gene expression.

Reminiscences, collaborations and reflections

This is a personal account by a semi old-timer who completed his official term as a professor of plant biochemistry at Nagoya University in Japan in 1992. My university student life began soon after the World War II (1948). I shared the hardships of many in my age group, in that life was difficult during my college years. I was fortunate to have the opportunity of studying in the USA on a Fulbright scholarship first at Purdue University (1955-1956), and then at the University of California, Berkeley (1956-1957). My graduate study and postdoctoral training in the new world were vitally refreshing and stimulating, which gave me the impetus for becoming a natural scientist associated with academic institutions. Consciously and subconsciously I was impressed by the friendly and liberal atmosphere surrounding young students as well as senior scholars in the United States. But more importantly, I was inspired by the critical and competitive minds prevailing among these people.The appointment as a biochemist at the International Rice Research Institute (IRRI) in the Philippines (1962-1964) was the real start of my professional career. The work was continued upon my return to Nagoya to become a staff member of the Research Institute for Biochemical Regulation (1964-1992). Throughout the years, my major research interest has covered photosynthesis as a whole, involving photosynthetic CO2-fixation (RuBisCO), carbohydrate metabolism, e.g. starch biosynthesis and breakdown (α-amylase), and metabolic regulation, which are interrelated in the basic metabolism of plant cells.I shall briefly describe in this article highlights from my studies and discoveries made and I shall also discuss their possible significance in plant metabolism, with the hope that it does not contradict my sense of humility: They are (a) discovery of ADPG in plants and its role in starch biosynthesis; (b) structure-function relationship of RuBisCO proteins, in particular on heterologous recombination of their subunits of plant-type enzyme molecules derived from the prokaryotic photosynthetic bacteria; (c) molecular evolution of RuBisCO genes; (d) mode of actions (formation, intracellular transport and secretion) of rice seed α-amylase and its structural characteristics (distinctive glycosylation), and (e) DNA methylation and regulatory mechanism of photosynthesis gene expression in plastids (amyloplasts). In each step of my research, I shared joy, excitement, disappointment, and agony with my colleagues, an experience that may be common to all researchers. Although it is now becoming well recognized among the scientific community in Japan, I want to point out that interaction of multinational scientific minds in the laboratory produces a vital and creative atmosphere for performance of successful research. I experienced and realized this important fact in my earlier days in the USA and the Philippines. Inasmuch as I believe that this is the most crucial element for any research laboratory to possess, I fondly remember the friendships gained with numerous overseas visitors and collaborators who have contributed immensely to our work.