The basic DNA-binding protein of Bombyx mori nuclear polyhedrosis virus: the existence of an additional arginine repeat

The basic DNA-binding protein of the Bombyx mori nuclear polyhedrosis virus (BmNPV) was purified by HPLC and a sequence of 45 amino acids from the N-terminus was determined. There were no detectable modifications such as N-terminal blockage, glycosylation, or phosphorylation. The amino acid sequence showed high homology to the predicted amino acid sequences of the basic proteins of Autographa californica NPV (AcNPV) and Orgyia pseudotsugata NPV (OpNPV) (90 and 76%, respectively), however, the BmNPV basic protein possessed an additional sequence of 10 amino acids. A DNA fragment encoding the basic protein was identified in a BmNPV DNA library by screening for possible DNA sequences coding for the basic protein's amino acid sequence. The nucleotide sequence of the basic protein of BmNPV was more similar to that of AcNPV (97%) than to that of OpNPV (62%). Homology plot analysis of the nucleotide sequence indicates that the BmNPV basic protein internal repeat evolved very recently.

Prothoracicotropic hormone of the silkworm, Bombyx mori: amino acid sequence and dimeric structure

Prothoracicotropic hormone (PTTH) of the silkworm, Bombyx mori, was purified and its primary structure determined for the most part. From sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified PTTH under non-reducing and reducing conditions, and the amino acid sequence and composition analyses of the carboxamidomethylated PTTH, we concluded that Bombyx PTTH has a dimeric structure consisting of two identical, or nearly identical subunits, held together by disulfide bond(s). There exist subunit variants that differ by deletion of only a few amino acid residues at the N-terminus, and possibly at the C-terminus also, giving rise to a high heterogeneity in the PTTH molecule. The amino acid sequence up to the 104th residue from the N-terminus of the longest subunit, except for the 41st residue, was determined by sequence analysis of fragment peptides produced by lysyl endopeptidase, chymotrypsin and V8 protease digestions, leaving only a short C-terminal sequence undetermined. Bombyx PTTH is expected to contain a carbohydrate chain bound to an asparagine at position 41, deduced from the cDNA sequence.

Determination of hippuric acid and o-, m- and p-methylhippuric acids in urine by capillary gas chromatography

A capillary gas chromatographic (GC) method for the simultaneous determination of urinary hippuric acid (HA) and o-, m- and p-methylhippuric acids (MHAs), metabolites of toluene and o-, m- and p-xylenes, respectively, is described. These metabolites are converted into their isopropyl derivatives by extractive alkylation with tetrahexylammonium ion as extracting agent and isopropyl bromide as alkylating reagent in benzene. The derivatives are analysed using a chromatograph equipped with hydrogen flame ionization detector, split injection system and DB-17 capillary column. Benzoylleucine is used as an internal standard. The derivatives are well separated within 5 min and no interfering peaks are observed. The calibration curves of HA and MHAs in the range 1-50 micrograms are linear and sufficiently reproducible for quantitative analysis. Urine can be analysed accurately and precisely by this method without prior clean-up of the sample.

An ECG marker of underlying right ventricular conduction delay in the hyperacute phase of right ventricular infarction or ischemia

Patients with extensive right ventricular (RV) infarction or ischemia often have an accompanying RV conduction delay. Such patients frequently show precordial ST-T wave elevation, which hides the late r' wave in lead V1, making it difficult to recognize the RV conduction delay during the hyperacute phase. We noted that such patients occasionally exhibited a "cove"-shaped ST-T elevation in lead V1, which strongly suggested the presence of this complication even in the hyperacute stage. This report describes three instances of RV infarction or ischemia with this characteristic electrocardiographic sign. This sign appears to be a marker of RV conduction delay during the hyperacute stage of RV infarction or ischemia.

Occurrence of free O-phosphoserine and O-phosphothreonine in porcine liver

The occurrence of free O-phosphoserine and O-phosphothreonine in porcine liver is demonstrated. These amino acids were separated from the tissue extracts by anion- and cation-exchange chromatography and thin-layer chromatography, and were identified by gas chromatography with flame photometric detection and gas chromatography-mass spectrometry. The contents of O-phosphoserine and O-phosphothreonine in the liver were estimated to be 377 +/- 13 ng/g and 115 +/- 2 ng/g, respectively.

[A new computerized system for electroencephalography at the Kochi Medical School Hospital: the present status and problems of electroencephalogram data filing systems]

The usual electroencephalography (EEG) recording consumes great amounts of paper, considerable storage space for records and much time and energy for their search and retrieval. In addition, we can not perform digitized analyses of the records with the present method. To solve these problems, our laboratory developed a new computerized system for EEG, in which data are retained in optic disks, and which has been in service for routine examination since December, 1988. The functions of the system and EEG filing system, include the collection, retention, retrieval, transmission and analyses of data with the reproduction of the original EEG and editing function of summary reports to be filed in the medical records. The summary report consists of summary, characteristic wave patterns picked up and edited from EEG, and spectral array and topographical mapping by digitized analyses of EEG. The condition for the collection of EEG data was 200 Hz/8 bit, and the reproduced wave patterns were accepted by all clinicians. The merits of the system include; (i) saving of paper, space and time needed for EEG, (ii) enabling the comparison of the wave patterns in the form of summary reports and (iii) the capability of digitized analyses of EEG by retaining the EEG data in the data base. The problems remaining to be improved for the system are the longer time required for examination (5-10 min) and the higher running cost (yen 460/order). Regarding the latter problem, a revised method which dispenses with recording paper is under consideration. That is, in the case of screening examinations, summary reports for medical records alone would be delivered to clinicians. This idea has been accepted by some clinicians. To realize the revised system, we presently are planning to establish a method to display EEG on CRT.

[A case of primary adenosquamous carcinoma of the stomach showing Borrmann 4 type]

Adenosquamous carcinoma is a rare histological type of gastric cancer. We reported a 61-year-old man with primary adenosquamous carcinoma of the stomach showing Borrmann 4 type. Gastrofibroscopic biopsy and lymph node biopsy showed squamous and adenosquamous carcinoma respectively. Operated specimen revealed a adenosquamous carcinoma with diffuse infiltration.

Eclosion hormone of the silkworm Bombyx mori. Expression in Escherichia coli and location of disulfide bonds

A gene encoding eclosion hormone (EH) from the silkworm, Bombyx mori was chemically synthesized, inserted into a secretion vector and expressed in Escherichia coli, leading to the production of biologically active EH. Sequence analysis of cystine-containing peptides in a thermolysin digest of this EH established the locations of 3 disulfide bonds in the molecule. Evidence was also obtained that the 6 residues at the NH2-terminal are dispensable but 4 residues at the COOH-terminal play an important role in EH activity.

Molecular cloning of the Bombyx mori prothoracicotropic hormone

Prothoracicotropic hormone (PTTH), a brain secretory polypeptide of insects, stimulates the prothoracic glands to produce and release ecdysone, the steroid essential to insect development. The complementary DNAs encoding PTTH of the silkmoth Bombyx mori were cloned and characterized, and the complete amino acid sequence was deduced. The data indicated that PTTH is first synthesized as a 224-amino acid polypeptide precursor containing three proteolytic cleavage signals. The carboxyl-terminal component (109 amino acids) that follows the last cleavage signal represents one PTTH subunit. Two PTTH subunits are linked together by disulfide bonds, before or after cleavage from prepro-PTTH, to form a homodimeric PTTH. When introduced into Escherichia coli cells, the complementary DNA directed the expression of an active substance that was functionally indistinguishable from natural PTTH. In situ hybridization showed the localization of the prepro-PTTH mRNA to two dorsolateral neurosecretory cells of the Bombyx brain.

Prognostic significance of alpha-1-antitrypsin in early stage of colorectal carcinomas

We have previously shown that human colorectal carcinoma cell lines, RCM-1 and CoCM-1, synthesize alpha-1-antitrypsin (alpha 1-AT) in culture. We have studied immunohistochemically the incidence of alpha 1-AT on histologic sections from paraffin-embedded tissues of surgically resected colorectal carcinomas and their metastatic foci, polypectomized adenomas, and normal mucosae. alpha 1-AT was detected in 89 (61%) of 145 carcinomas (including 14 carcinomas in adenoma), and 12 (39%) of 31 adenomas. But only 2 (4%) of 55 normal colorectal mucosae were positive for alpha 1-AT. In metastatic tumor cells of colorectal carcinomas in lymph nodes and other organs, alpha 1-AT positivity was 60% and 82%, respectively. The incidence of alpha 1-AT was markedly higher in advanced adenocarcinomas than in early ones and more frequent in adenocarcinomas of right side (including transverse colon) than those of left side and rectum, regardless of their histological malignancy grades. In mucinous carcinomas the frequency was greater (8 of 9 cases) than in conventional adenocarcinomas. Clinical follow-up of the patients with colorectal carcinomas suggested that alpha 1-AT positivity in Dukes' stage A/B tends to correlate with unfavorable prognosis irrespective of the grade of histologic differentiation of carcinoma, but there is no significant relation in Dukes' stage C/D. Our findings suggest that alpha 1-AT in colorectal carcinoma is related to the invasive and metastatic capacity. It may thus serve as a biologic marker for prognosis of colorectal carcinomas at relatively early stages (Dukes' stage A/B).

Evaluation of synthetic sphingosine, lysosphingolipids and glycosphingolipids as inhibitors of functional responses of human neutrophils

Human neutrophils, when exposed to soluble stimuli, aggregate, release oxygenated products of arachidonic acid and generate active oxygen species. Sphingolipid-derived products such as sphingosine and lysosphingolipids have been shown to exert selective actions on a variety of cell types, including neutrophils. Therefore, to determine the structural basis for selective inhibition of neutrophil responses by naturally occurring sphingolipids, seven compounds were prepared by total organic synthesis, and their impact on neutrophils in suspension has been studied. The compounds synthesized included sphingosine, psychosine, lactosyl lysosphingolipid, globotriaosyl (Gb3) lysosphingolipid, galactosyl cerebroside, lactosyl ceramide and Gb3 ceramide. The neutrophil responses studied were aggregation, leukotriene generation and superoxide anion production. When exposed to non-cytotoxic levels of the synthetic compounds, as monitored by exclusion of Trypan Blue, none of the synthetic sphingolipids inhibited A23187-induced aggregation of neutrophils. Only lactosyl lysosphingolipid, at a concentration of 1 microM, significantly inhibited aggregation induced by fMetLeuPhe; the other compounds in this series including sphingosine were without effect at equal molar concentrations (1 microM). Aggregation induced by phorbol 12-myristate 13-acetate (PMA) (0.1 microM) was significantly blocked by only two of the synthetic sphingolipids (1 microM). At concentrations below 1 microM, these inhibitory actions were not evident, nor was it possible to assign a structure-activity relationship for this series of compounds. None of the synthetic sphingolipids effectively inhibited the generation of superoxide anions induced by PMA. In addition, neither synthetic sphingosine nor psychosine affected either the formation or metabolism of leukotriene B4. Taken together, the results provide further evidence that sphingolipids, when added to intact cells, are not potent selective inhibitors of functional responses of human neutrophils.

Enhanced O6-methylguanine-DNA methyltransferase activity in transgenic mice containing an integrated E. coli ada repair gene

The E. coli ada gene encodes O6-methylguanine DNA methyltransferase (O6MTase) which repairs the methylation of guanine at the O6 position in DNA. After recombination with a Chinese hamster metallothionein I gene promoter, the ada gene was microinjected into C3H/HeN mouse zygotes. Eventually, transgenic mice containing the ada fusion DNA were generated. The integrated ada DNA complex was transmitted to the progeny in a mode conforming to tandem integration at a single chromosome site, and homozygotes were also obtained from an inter-transgenic mouse cross. RNA transcripts of the chimeric ada gene were identified in the livers of these transgenic mice using dot and Northern blot analyses. O6MTase activity was increased in the liver of transgenic mice of line No. 708, and was more than 3 times the activity found in non-transgenic mice, especially in the transgenic homozygotes. The ada gene product was detected in the liver of a transgenic homozygote by immunoblot analysis. These transgenic mice have great potential for analysis of the role played by O6MTase in chemical carcinogenesis.

Establishment of the experimental conditions for inducing saccular cerebral aneurysms in primates with special reference to hypertension

To find out the optimum experimental conditions for the induction of saccular cerebral aneurysms in primates, various procedures for inducing renal hypertension were used in cynomolgus monkeys treated with ligation of unilateral carotid artery and beta-amino-propionitrile feeding. Animals were divided into four groups. In the first group, both kidneys were simultaneously compressed with a figure-eight ligation. In the second group, the kidneys were ligated at an interval of one week. In the third and fourth groups, posterior branches of both renal arteries were ligated at the same time, or at an interval of one week, respectively. Hypertension about 200 mmHg was produced only in the last group and aneurysms were noted in more than half of these hypertensive animals. The best procedure for renal hypertension to induce cerebral aneurysms was proved to be ligation of the posterior branches of both renal arteries at an interval of one week. We can conclude that lasting severe hypertension is essential for inducing cerebral aneurysms in monkeys.

[Bone inductive activity of hydroxyapatite-bone morphogenetic protein complex]

Bone morphogenetic protein (BMP) is known to be a protein which induces new bone at heterotopic sites. Purification of BMP has not been perfected, and obtaining large amounts of BMP is very difficult, so it seems better to use some carrier or frame material for BMP to work effectively. Various kinds of hydroxyapatite (HAP) have been used to repair periodontal osseous defects, but they do not have osteogenetic or osteoinductive properties. If osteoinductive proteins such as BMP could retain their biologic properties after being implanted into living tissue with HAP, it would be an advantage in repairing periodontal osseous defects. In this experiment, we prepared BMP-HAP complex and investigated its osteoinductive activity. BMP was extracted from bovine cortical bones in accordance with the Urist's procedure. The ability of this BMP to stimulate new bone growth was ensured by implantation in the muscle pouch of mice. HAP was synthesized by the wet method. The BMP-HAP complex was implanted in the muscle pouch of mice, and osteoinduction was examined 3, 7, 14, and 21 days after implantation to assess its osteo-inductive ability. New bone formation was studied by roentgenographic and histologic observation. In the BMP-HAP group, new bone formation was seen on the roentgenograms and new cartilage and bone were observed histologically in the tissue surrounding the apatite. In the HAP group, no new cartilage or bone formation was noted.

Amino acid sequence of pheromone-biosynthesis-activating neuropeptide (PBAN) of the silkworm, Bombyx mori

We have isolated two distinct pheromone-biosynthesis-activating neuropeptides (PBAN), named PBAN-I and -II, as fully oxidized forms of Met residues from adult heads of the silkworm, Bombyx mori. PBAN-I was identical with the PBAN which we had isolated before. The complete amino acid sequence of PBAN-I, a total of 33 amino acid residues, was determined as H-Leu-Ser-Glu-Asp-Met-Pro-Ala-Thr-Pro-Ala-Asp-Gln-Glu-Met-Tyr-Gln-Pro-As p-Pro- Glu-Glu-Met-Glu-Ser-Arg-Thr-Arg-Tyr-Phe-Ser-Pro-Arg-Leu-NH2. Synthetic PBAN-I after oxidation with H2O2 was chromatographically identical with the isolated PBAN-I. Examination of PBAN activity of synthetic analogues indicated that the carboxyl-terminal portion of PBAN-I was important for biological activity.

Extraskeletal mesenchymal chondrosarcoma in a cow

A mesenchymal chondrosarcoma found in a 7-year-old Holstein cow was studied by light and electron microscopy. There was a primary site in the subcutaneous tissue at the base of the neck and metastases in the lungs, pleura, broncho-mediastinal lymph nodes, kidneys and heart. The neoplasm was composed of undifferentiated mesenchymal tissue, myxoid tissue and chondroid tissue. The neoplastic cells of the former two tissues were characterized by desmosome-like junctions and moderate to small amounts of rough endoplasmic reticulum (RER).

Long-term angiographic follow-up results in patients undergoing percutaneous transluminal coronary angioplasty

Long-term effects following percutaneous transluminal coronary angioplasty (PTCA) were examined using follow-up coronary angiography (CAG) in 49 lesions in cases in which the procedure was considered to be successful. Follow-up CAG was performed 2-5 times (average, 2.7 times) per patient during a period of 1 year to 3 years and 7 months (average, 1 year and 10 months). The luminal diameter of the PTCA sites was expressed as the percentage of the value immediately after the procedure. Narrowing by 10% or more was observed in 17 lesions 3-8 months after PTCA but in only 4 lesions on the final CAG. The luminal diameter of the PTCA site was significantly greater (p less than 0.05) 2 years after PTCA in comparison to the findings after 1 year. These results suggest excellent long-term effects at the PTCA site.

[Lung lavage and artificial surfactant replacement therapy--animal experimentation and clinical application]

Lung lavage may cause a surfactant deficient condition. We examined the effect of artificial surfactant replacement on the post-lavage condition in rabbits and in a patient with alveolar pulmonary proteinosis. Adult rabbits (n = 21) were subjected to whole-lung lavage, and the PaO2 was made to decrease to less than 70 mmHg (FIO2 = 1.0). In the replaced group (n = 11), an artificial surfactant which was a saline suspension of lipids (mixture of dipalmitoylphosphatidylcholine, phosphatidylglycerol and tripalmitin) was administered into the airway. The PaO2 was elevated to a level higher than 400 mmHg at 30 min after the surfactant replacement. On the other hand, the PaO2 in the non-replaced group (n = 10) remained below 100 mmHg. In the patient with alveolar pulmonary proteinosis, we performed the artificial surfactant replacement after the therapeutic lung lavage. By the replacement, the PaO2 increased from 89 mmHg (FIO2 = 1.0) to 128 mmHg. These results demonstrate the therapeutic effects of surfactant replacement on the acute respiratory failure induced by lung lavage.

Properties of N-methyl-N-nitrosourea-resistant, Mex- derivatives of an SV40-immortalized human fibroblast cell line

We have selected two N-methyl-N-nitrosourea (MNU)-resistant derivatives of the SV40-transformed, alkyltransferase-deficient (Mex-) human fibroblast cell line MRC5V1. Both derivatives remain Mex-. They are cross-resistant to methylmethanesulphonate (MMS) and 6-thioguanine (6TG) but not 2,6-diaminopurine. They show increased sensitivity to the bifunctional chloroethylating agent mitozolomide (MTZ). We have transfected MRC5V1 and one of our MNU-resistant lines with the bacterial O6-methylguanine (O6-MeG)-DNA methyltransferase (ada) gene. Transfectants of MRC5V1 are significantly more resistant to MNU but exhibit only a small increase in resistance to MMS and MTZ. Transfectants of the MNU-resistant derivative exhibit only a small additional increase in resistance to MNU, no further increase in resistance to MMS and a large increase in resistance to MTZ. The pattern of resistance to cytotoxic agents of these transfectants suggests that a second mechanism of resistance to MNU, independent of alkyltransferase expression, is operating in our resistant lines. This mechanism apparently enables the cells to tolerate O6-MeG and 6TG, but not chloroethyl adducts in their DNA.