Overproduction of beta-glucosidase in active form by an Escherichia coli system coexpressing the chaperonin GroEL/ES

beta-Glucosidase from Cellvibrio gilvus was successfully overproduced in soluble form in Escherichia coli, with the coexpression of GroEL/ES. Without the GroEL/ES protein, the beta-glucosidase overexpressed in E. coli constituted a huge amount (80%) of the total cellular protein, but was localized in the insoluble fraction, and little activity was detected in the soluble fraction. Coexpression of the E. coli GroEL/ES had a drastic impact on the proper folding of the beta-glucosidase; 20% of the overexpressed enzyme was recovered in the soluble fraction in active form. In addition, the synergistic effect of GroEL/ES and the low induction temperature led to 70% solubilization of the total expressed target protein and more than a 20-fold increase in activity. Similar effects of GroEL/ES were also observed on the overexpressed beta-glucosidase from Agrobacterium tumefaciens.

[HLA antigens are associated in seronegativity to cytomegalovirus(CMV)]

Cytomegalovirus(CMV) is ubiquitous in the world, but the rate of CMV antibody positivity (seropositivity) in adults varies geographically. In Japan, CMV seropositivity in adults in 90% and we perceived seronegative adults tend to remain seronegative in 10 years follow up study. We have performed HLA typing 125 seronegative healthy donors of 28 years and up (28-57, Ave.35), and the results were compared with those of healthy donors in same area and whole Japan (data from 10th HLA workshop). Incidence of HLA-A33 and HLA-Cw4 were significantly higher in seronegatives than control groups. This report suggests possible involvement of HLA type in CMV negativity.

Simultaneous measurement of amplitude and phase in surface second-harmonic generation

The intensity and the phase in surface second-harmonic generation were simultaneously measured by use of an ac optical balanced homodyne detection system. In this system the surface second-harmonic wave was superimposed upon a local oscillator wave generated by a barium borate nonlinear optical crystal and then detected as an interference signal. Extremely high sensitivity of 3 aW (6 photons/s) and high precision were achieved by use of a lock-in amplifier, in which an interference signal of fundamental waves was used as a reference signal. Simultaneous measurement of the intensity and the phase in surface second-harmonic waves generated from native-oxidized Si(111) surfaces is demonstrated.

Ykt6p, a prenylated SNARE essential for endoplasmic reticulum-Golgi transport

Vesicular transport between secretory compartments requires specific recognition molecules called SNAREs. Here we report the identification of three putative SNAREs, p14 (Sft1p), p28 (Gos1p), and a detailed characterization of p26 (Ykt6p). All three were originally isolated as interacting partners of the cis Golgi target membrane-associated SNARE Sed5p, when Sec18p (yeast NSF) was inactivated. YKT6 is an essential gene that codes for a novel vesicle-associated SNARE functioning at the endoplasmic reticulum-Golgi transport step in the yeast secretory pathway. Depletion of Ykt6p results in the accumulation of the p1 precursor (endoplasmic reticulum form) of the vacuolar enzyme carboxypeptidase Y and morphological abnormalities consistent with a defect in secretion. Membrane localization of Ykt6p is essential for protein function and is normally mediated by isoprenylation. However, replacement of the isoprenylation motif with a bona fide transmembrane anchor results in a functional protein confirming that membrane localization, but not isoprenylation per se, is required for function. Ykt6p and its homologues are highly conserved from yeast to human as demonstrated by the functional complementation of the loss of Ykt6p by its human counterpart. This is the first example of a human SNARE protein functionally replacing a yeast SNARE. This observation implies that the specific details of the vesicle targeting code, like the genetic code, are conserved in evolution.

[Choroidal lesions and surgical treatment of bullous retinal detachment]

To define choroidal lesions of bullous retinal detachment, we performed indocyanine green angiography (IA) on 20 eyes of 10 patients with bullous retinal detachment. Four of these eyes were treated with sclerectomy and sclerostomy (Gass), and the benefit was evaluated. IA showed the following choroidal abnormalities: choroidal filling delay in the macular region (6 of 18 eyes, 33%) and underneath the leaking sites (9 of 18 eyes, 50%), localized (1 eye, 5%) and extended (18 eyes, 90%) choroidal venous dilatation, and intrachoroidal hyperfluorescence (all eyes, 100%). After the surgical treatment, retinal detachments resolved within 9 weeks (mean 5.3 weeks). Since choroidal filling delay, choroidal venous dilatation and intrachoroidal hyperfluorescence were observed, it is suggested that choroidal congestion plays a causative role in bullous retinal detachment. Sclerectomy and sclerostomy seemed to be beneficial in treatment of this condition.

Large intensity noise from symmetric low-Q cavity semiconductor lasers driven with pump-noise-suppressed current injection in the high-pump regime

We have measured the intensity noise from symmetric low-Q cavity laser diodes (LD's) operated far above threshold in a constant-current mode. The single-sided output noise exhibits significant dependence on the mirror reflectivities of the laser cavity, in good agreement with the theoretical predictions based on a quantum-mechanical traveling-wave analysis. In an antireflection-coated LD with a residual mirror reflectivity of 5%, intensity noise as large as 9 dB above the shot-noise level was observed at a pumping rate of 10 times the threshold. This is caused by amplification of the vacuum-field fluctuations coupled by the low-reflectivity mirrors into the laser cavity.

A phase I study of irinotecan and infusional cisplatin with recombinant human granulocyte colony-stimulating factor support in the treatment of advanced non-small cell lung cancer

We conducted a phase I study to examine whether support with recombinant human granulocyte colony-stimulating factor (rG-CSF) would permit dose intensification of irinotecan (CPT-11) in combination with cisplatin (20 mg/m2 x 5 days) in non-small cell lung cancer (NSCLC) patients. CPT-11 was administered by bolus infusion at a starting dose of 100 mg/m2 on day 1, followed by serial increments at 20 mg/m2, given every 4 weeks. The major toxic effects were granulocytopenia and diarrhoea. The response rate was 55% (11/20). The optimum dose for phase II studies appears to be 20 mg/m2/day (5-day continuous infusion) for cisplatin and 160 mg/m2 (day 1) for CPT-11 with rG-CSF support in NSCLC.

[Diagnosis of pleural dissemination lung cancer by thin-section CT--a prospective study]

In this prospective study, thin-section CT was used to diagnose pleural dissemination in patients with pulmonary adenocarcinomas in which the primary lesion was found to be adjacent to the pleural surface by conventional CT. The subjects were 32 patients (25) who had undergone resection and 7 who had not with pulmonary adenocarcinoma without pleural effusion from among the 136 patients with pulmonary adenocarcinoma examined at our institution over 3 years. Thin-section CT images of three regions were obtained, and these included the pleural surface adjacent to the lesion, the minor fissure, and the diaphragmatic dome. Histopathological examination revealed pleural dissemination in 12 patients (5 who had undergone resection and who had not), in 2 of whom a diagnosis could not be made preoperatively. Pleural dissemination was diagnosed by CT in 12 patients; there were 2 false positives. In 6 patients who did not undergo resection, cancerous cells were found in fluid obtained by percutaneous pleural lavage, and mediastinal lymph node metastases or distant metastases were also detected. The diagnostic rate of CT was as follows interlobar space. 100% (7/7); mediastinum, 75% (3/4); diaphragm, 71% (5/7); and chest wall, 57% (4/7). In the patients who underwent resection, sensitivity was 100% for the interlobar space, but it was 0% to 33% for other pleural surfaces.

[A randomized controlled study of post-operative adjuvant therapy in non-small cell lung cancer]

The efficacy of postoperative adjuvant chemo- and chemoimmunotherapy in non-small cell lung cancer was evaluated in a multicentric prospective randomized study. From September 1987 to June 1990, resected lung cancer patients were randomly stratified into three groups. Group A received 2 courses of chemotherapy with CDDP and VDS following operation. Group B was administered UFT daily for 1 year after 2 courses of CDDP. Group C received intrapleural administration of OK-432 after lung resection, then UFT and OK-432 once every 2 weeks for 1 year. Out of 94 cases, analyses were carried out on 87 of eligible cases. The five-year survival rate was 56.8% in stage I (43 cases), 73.3% in stage II (12 cases), 18.8% in stage IIIA (24 cases), 50% in stage IIIB (2 cases) and 33.3% in stage IV (6 cases). The five-year survival rate in group A was 32.2%, 55.2% in group B and 53.9% in group C, and no statistical difference was recognized between 3 groups. But in the cases of noncurative resection, the 5-year survival rate was significantly low in group A compared with Group B or C. Similarly, the cases with low-grade TP (<6.0 g/dl) or low response of PPD skin reaction (< 12mm) showed a significantly low 5-year survival rate only in group A. From these results, it was suspected that aggressive chemotherapy provides no benefit for postoperative lung cancer patients with advanced disease.

[Evaluation of retinal light damage in aphakic chicken eyes using monochromatic ERGs]

We evaluated light damage to cones using monochromatic electroretinograms (ERGs) in lensectomized chicken eyes. During exposure of the retina to light to produce light damage, an ultraviolet-absorbing (UV) filter was placed in front of some eyes (non-UV irradiated group) and not placed in front of others (UV irradiated group). Blue cone and red cone ERGs were recorded from the UV irradiated group before and at 1, 3, 5, 10, 15, and 30 days after the damage, and from the non-UV irradiated group before and at 1 day after the light exposure. From the ERG.b-wave amplitudes, spectral sensitivities of the blue and red cones were obtained. The blue cone sensitivity of the UV irradiated group was significantly attenuated compared with the non-UV irradiated group (p < 0.01), but recovered between 5 and 15 days after the damage. The present study suggested that the blue cones are more susceptible to light stress than the red cones and that this degree of blue cone damage is reversible. Ultraviolet rays seem to be mainly responsible for light damage to the blue cones.

Capillary-zone electrophoretic analyses of the proteins and amino acid components in cerebrospinal fluid of central nervous system diseases

Analysis systems for protein and amino acid components in cerebrospinal fluid (CSF) from patients with a variety of central nervous system (CNS) diseases were established employing capillary-zone electrophoresis (CZE). Under the conditions employed, the major proteins in CSF and the concurrent sera were separated into several respective fractions, and in the obtained electropherograms of serum proteins, the % values of areas of each major protein fraction (from gamma-globulin to albumin) were in close accord with those in the densitograms of stained protein bands after electrophoresis on cellulose-acetate strips which had been done as a routine laboratory test in the hospital. Some unusual migration patterns of major proteins were observed in various CNS diseases, and an increase of glutamine in hepatic encephalitis was also detected on the electropherograms. A peak responsible for a minor protein component with the molecular weight of 10000--30000, which was tentatively identified as beta-trace protein, was found to be contained in all the CSF samples examined, and its concentration levels were higher in some patients with cerebral infarction and multiple sclerosis. These results suggest that CZE can become a powerful aid in analyses of the protein and amino acid components in CSF for biochemical diagnosis of CNS diseases.

Purification and characterization of membrane-bound chitin synthase

The membrane-bound chitin synthase, a key enzyme of chitin biosynthesis, was purified, for the first time to homogeneity as a zymogen form. Digitonin could solubilize the enzyme from microsomal fraction of the filamentous fungus Absidia glauca, with 60-70% of the enzyme activity. The solubilized form of the enzyme was effectively purified by a sequence of chelating Sepharose, concanavalin A-Sepharose, and Mono Q column. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified enzyme gave a single band with a molecular weight of 30,000. IgG prepared against this 30-kDa species on SDS-polyacrylamide gel electrophoresis immunoprecipitated chitin synthase. The purified enzyme existed as a zymogen, was converted into active form by treatment with trypsin, and the limited digestion with trypsin produced a little smaller polypeptide (28.5 kDa) of which the amino-terminal sequence was identical to the zymogen. The purified enzyme was the glycoprotein and showed a requirement for Mg2+. N-Acetylglucosamine stimulated the enzyme activity approximately 5-fold and polyoxin D, an analogue of substrate, and UDP, a byproduct of enzyme reaction, strongly inhibited the enzyme activity.

[Color sensation of pseudophakic eye from a viewpoint of electrophysiological study]

Monochromatic ERG b-waves were recorded in normal eyes, cataractous eyes and pseudophakic eyes implanted with non-UV or UV IOLs. ERG b-waves were elicited by fourteen monochromatic stimulus lights ranging from 400 to 660 nm under white light adaptation, and spectral response curves were obtained from b-wave amplitudes. Compared with normal eyes or cataractous eyes, the relative b-wave amplitude of pseudophakic eyes was significantly larger in the short wavelength range from blue to green. Except for 400 nm, the spectral response curve of the eyes implanted with UV IOLs was similar to that of eyes implanted with non-UV IOLs. These results suggested that dyschromatopsia might not only occur in eyes implanted with non-UV IOLs but in eyes with UV IOLs.

Photon Number Squeezed States in Semiconductor Lasers

Electromagnetic fields, with the noise on one quadrature component reduced to below the quantum mechanical zero-point fluctuation level and the noise on the other quadrature component enhanced to above it, are currently of great interest in quantum optics because of their potential applications to various precision measurements. Such squeezed states of light are usually produced by imposing nonlinear unitary evolution on coherent (or vacuum) states. On the other hand, squeezed states with reduced photon number noise and enhanced phase noise are generated directly by a constant current-driven semiconductor laser. This is the simplest scheme for the generation of nonclassical light, and so far it has yielded the largest quantum noise reduction. The mutual coupling between a lasing junction and an external electrical circuit provides opportunities for exploring the macroscopic and microscopic quantum effects in open systems.

[Effect of continuous epidural infusion of morphine on postoperative glucose metabolism]

Plasma growth hormone (GH), insulin, prolactin and blood glucose levels were measured to evaluate postoperative pain relief either with epidural morphine or systemic analgesics in 16 patients who underwent gastrectomy. Continuous epidural morphine with a pump (CADD-PCA, Model 5200P, Pharmacia) was given to eight (epidural morphine group) patients. A bolus of epidural morphine was administered through an indwelling thoracic (Th8.9) catheter at 3 hrs prior to the expected end of surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042 mg.hr-1 with the pump during and after anesthesia and surgery with gradually decreasing dose until the third postoperative day. The remaining eight patients (systemic analgesics group) repeatedly received intravenous or intramuscular pentazocine and buprenorphine when needed. Plasma GH levels increased significantly only on the first postoperative day in both groups. Plasma insulin levels increased significantly on the first postoperative day in both groups. Blood glucose levels increased significantly at the end of surgery and during the following three postoperative days in both groups. There are no statistical differences in plasma GH, insulin and blood glucose levels between the two groups. Plasma prolactin concentrations increased significantly at the end of surgery and they were significantly higher in the systemic analgesic group than in the epidural morphine group. They, however, returned to the previous day's levels on the first postoperative day in both groups. Our study suggests that continuous epidural infusion of morphine has no suppressing effect on postoperative changes in plasma GH, insulin, prolactin and blood glucose levels as compared with systemic analgesic regimen.

[Plasma catecholamine levels following continuous epidural infusion of morphine for postoperative analgesia in surgical patients]

Plasma catecholamine levels were measured to evaluate postoperative pain relief either with epidural morphine or systemic analgesics in sixteen patients who underwent gastrectomy. Eight patients (epidural morphine group) obtained postoperative analgesia with continuous epidural morphine with a pump (CADD-PCA, Model 5200P, Pharmacia). A bolus of morphine was administered through an indwelling thoracic (Th8 X 9) epidural catheter 3 hrs prior to the proposed end of the surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042mg.hr-1 by the pump during and after anesthesia and surgery with gradual decrease in dose until the third postoperative day. The remaining eight patients (systemic analgesics group) received repeatedly intravenous or intramuscular pentazocine and buprenorphine when needed. Plasma epinephrine levels increased significantly at the end of surgery in both groups, and were higher in the systemic analgesics group than those in the epidural morphine group. In the epidural morphine group, the catecholamine levels decreased to the previous day's levels on the first postoperative day and afterward, but remained high during three postoperative days in the systemic analgesics group. Plasma norepinephrine levels increased significantly at the end of surgery and afterward in both groups. However, they were significantly higher in the systemic analgesics group than in the epidural morphine group. Plasma dopamine levels were unchanged in the epidural morphine group during the surgical procedures, but they increased significantly on the first postoperative day and thereafter in the systemic analgesics group. Our study suggests that continuous epidural infusion of morphine is adequate for postoperative pain relief and exerts a suppressing effect on plasma catecholamine levels as compared with systemic analgesics regimen.

Observation of amplitude squeezing from semiconductor lasers by balanced direct detectors with a delay line

Simultaneous measurement of the signal-noise level and the corresponding shot-noise level using balanced direct detectors with a delay line is demonstrated. We have observed 1.3-dB squeezing from a constant-current-driven semiconductor laser, which is consistent with 3-dB squeezed noise at the output of the laser when the detection efficiency is taken into account.

[Effect of continuous epidural infusion of morphine for postoperative analgesia on pituitary-adrenocortical function]

Plasma levels of cortisol, ACTH and beta-endorphin like immunoreactivity (beta-ELI) were measured to evaluate postoperative pain relief with epidural morphine and systemic analgesics in conjunction with endocrine functions in 16 patients who underwent gastrectomy. Eight of these patients (epidural morphine group) obtained postoperative analgesia with continuous epidural infusion of morphine with a pump as in our previous report. A bolus of epidural morphine was administered through an indwelling thoracic (Th8,9) catheter at 3 hrs prior to the proposed end of the surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042 mg.hr-1 with a pump (CADD-PCA, Model 5200P, Pharmacia) during and after anesthesia and surgery with gradual decrease in dose until the third postoperative day. The remaining eight patients (systemic analgesics group) repeatedly received systemic pentazocine and buprenorphine when needed. Plasma cortisol levels increased significantly at the end of surgery and after in both groups. However plasma concentrations of cortisol in the epidural morphine group were significantly lower than those in the systemic analgesics group on the first and second postoperative days. Plasma levels of ACTH and beta-ELI increased significantly at the end of surgery but returned to levels of the previous day in both groups postoperatively. Our study suggests that continuous epidural infusion of morphine is adequate for postoperative pain relief and has suppressing effect on plasma cortisol levels as compared with systemic analgesics regimen.

Dyspnea resulting from accumulation of pleural effusion after radical neck dissection. A case report

The patient became dyspneic 3 days after radical neck dissection on the left side. A chest radiography showed bilateral pleural effusion.During the operation, a lymphatic leak was noted. In this case, the factor of an associated perforation of the pleural had not been demonstrated. Fresh frozen plasma was administered and positive end-expiratory pressure was applied. The patient had no residual pulmonary sequelae.

Endopyelopyelotomy: percutaneous surgery for ureteropelvic junction obstruction in a bifid pelvis: further experience

A patient with a bifid pelvis and ureteropelvic junction obstruction of the lower system was managed successfully by endopyelopyelotomy. This percutaneous procedure consists of creation of an internal fistula between the 2 pelves by incision of the intervening tissue with an optical urethrotome. This procedure provided a satisfactory and reproducible result.

[Spinal anesthesia with isobaric bupivacaine for percutaneous nephro-ureterolithotomy]

The duration of analgesia and the cardiovascular changes during anesthesia of spinal blockade with isobaric bupivacaine were examined in 36 patients between 21 and 75 years old undergoing percutaneous nephro-ureterolithotomy. Injection of 0.25% or 0.5% bupivacaine 3.0-4.0 ml through the L3-4 or L2-3 intervertebral space in the horizontal posture resulted in spread of hypalgesia to T6 in 30 patients and of analgesia to T6 in about a half of the patients. In six patients, another intrathecal injection of 2 ml of bupivacaine was performed because their analgesia level had been under T8. Although the operation took 32-141 min. (mean 77.7 +/- 27.5 min.), there was no case requiring exigent exchanging anesthesia for general anesthesia. The frequencies of the hypotension, bradycardia and nausea in spinal blockade with isobaric bupivacaine were not so different from those of the previous epidural anesthesia in 29 patients undergoing the same operation. Most of the cardiovascular changes in the spinal blockade with isobaric bupivacaine happened within 20-30 min. after intrathecal injection of bupivacaine. Spinal anesthesia with isobaric bupivacaine proved satisfactory for percutaneous nephro-ureterolithotomy.

[Ureteral injury in endourological treatment of renal and ureteral calculi]

Percutaneous and transurethral removal of renal and ureteral calculi was performed in 109 cases. Targeted calculi were successfully removed in 105 cases (96.3 per cent), but in five cases combined percutaneous and transurethral procedures were required. Although endourological stone removal resulted in low morbidity rates in many other series, some major complications have also been reported. They include arteriovenous fistula, colo-cutaneous fistula, nephro-duodenal fistula and ureteral avulsion. There were two severe complications in our early experience as well. In one case, a ureteral stenosis was found seven months after two sessions of percutaneous ultrasonic lithotripsy for an upper ureteral stone, and in the other case, a mid-ureteral avulsion was caused by ureteroscopic manipulation. Besides these, we experienced several minor pelvic and ureteral perforations which were easily controlled only by ureteral stent placement. Causes and management of ureteral complications in endourological treatment of renal and ureteral calculi are discussed.

[Incidentally detected renal cell carcinoma: report of two early small cases]

We report two cases of small renal cell carcinoma, which were incidentally detected by abdominal computed tomography (CT) and ultrasound. Both tumors were less than 15 mm in diameter and low grade, stage I lesions. Incidentally found renal cancer does not always indicate better prognosis. However, in selected patients with small tumors, surgical enucleation may be an acceptable method of treatment even if the contralateral kidney is normal. Renal screening should be a routine part of abdominal ultrasound. In our institution, ultrasound revealed incidental renal cancer in 0.035% of non-urologic patients.