Marked improvement of diabetic diarrhea with the somatostatin analogue octreotide

Somatostatin and its long-acting analogue octreotide have been used in various diarrheal disorders, including neoplastic and nonneoplastic diseases of the gastrointestinal tract. In two insulin-dependent diabetic patients with autonomic neuropathy and chronic steatorrheic diarrhea refractory to conventional medications, subcutaneous administration of octreotide markedly improved the volume and frequency of stools in both patients. This change was accompanied by a clear improvement in their rapid gastrointestinal tract transit times. The treatment also greatly improved their orthostatic hypotension. No adverse effects of octreotide were observed after treatment for 7 months in one patient and 2 months in the other.

[Successful treatment of refractory extensive small cell lung cancer by oral etoposide]

A 62-year-old male was admitted with chest pain and lymphadenopathy at neck for 2 weeks. His admission chest radiograph revealed a large tumor shadow, intrapulmonary metastasis and apical involvement. The patient was diagnosed as having small cell lung cancer from sputum cytology. Clinical staging was extensive disease and performance status was 1. The patient was treated by combination chemotherapy with cisplatin, adriamycin and etoposide. After 4 cycles, his chest radiograph was unchanged and he showed remarkable bone marrow suppression and superior vena cava syndrome. Thus, the initial combination chemotherapy was thought to be ineffective. Then, administration of oral etoposide (50 mg/body) was started and continued until the appearance of leukopenia (< 3,000/mm3). One month's administration of oral etoposide made the tumor shadow on his chest radiograph disappear. This disappearance was reserved for more than 4 months with oral etoposide. The average administration of oral etoposide was 2.7 day/week.

Complementary improvement of the method for determining cholinergic activities in the small intestine and its application to experiments in vivo

The concentration of acetylcholine (ACh) in rat jejunum that had been homogenized with an ultra-high-speed homogenizer (Biotron) was significantly higher than that in jejunum homogenized with a glass homogenizer. Rats were injected once or repeatedly for 10 days with a muscarinic agonist, pilocarpine (1 mg/kg), or a muscarinic antagonist, scopolamine (5 mg/kg). Animals were killed 20 min or 24 hr after single or consecutive injections, respectively, for determinations of cholinergic activities in the jejunum. Single treatment: Pilocarpine did not cause significant changes in the level of ACh, the activity of acetylcholinesterase (AChE), the binding of [3H]quinuclidinyl benzilate (QNB) or the contractile responses to ACh. Scopolamine reduced the level of ACh and binding of [3H]QNB without inducing significant changes in the activity of AChE and the contractile response. Consecutive treatment: Pilocarpine reduced the binding of [3H]QNB by changing the value of Bmax and reduced the contractile response without affecting the level of ACh or the activity of AChE. Scopolamine increased the binding of [3H]QNB without any effects on the level of ACh, the activity of AChE or the contractile response. In summary, it is possible to determine the level of ACh in a tissue as hard as intestine by homogenization with a Biotron and to assess the cholinergic situation in the intestine of animals that have been poisoned with various agents by estimating cholinergic activities.

Formation of sheared G:A base pairs in an RNA duplex modelled after ribozymes, as revealed by NMR

The thermal stability and structure of an RNA duplex, r(GGACGAGUCC)2, the base sequence of which was modelled after both a hammerhead ribozyme and a lead ribozyme, were studied by CD and NMR. We previously demonstrated that the corresponding DNA duplex, d(GGACGAGTCC)2, formed unique 'sheared' G:A base pairs, where an amino proton, instead of an imino proton, of G is involved in the hydrogen bonding, and G and A bases are arranged 'side by side' instead of 'head to head' (Nucleic Acids Res. (1993) 21, 5418-5424). CD melting profiles showed that the RNA duplex is thermally more stable than the corresponding DNA duplex. NMR studies revealed that sheared G:A base pairs are formed in the RNA duplex, too, although the overall structure of the RNA is the A form, which differs from the B form taken on by the corresponding DNA. A model building study confirmed that sheared G:A base pairs can be accommodated in the double helical structure of the A form. A difference between the RNA and DNA duplexes in the stacking interaction involving G:A mismatch bases is also suggested. The demonstration that sheared G:A base pairs can be formed not only in DNA but also in RNA suggests that this base pairing plays an important role regarding the RNA structure.

Lack of degradation of antithrombin III by tissue-type plasminogen activator or plasmin

BACKGROUND

Coronary thrombolysis is an established initial approach in the treatment of acute transmural myocardial infarction. However, conjunctive anticoagulation regimens are often suboptimal. Heparin is the only intravenously administered anticoagulant approved by the USA Food and Drug Administration commonly used for this purpose. Unfortunately, it exhibits potential limitations that may either predispose arteries to reocclusion or result in failure of initial recanalization. This study was designed to determine whether consumption of heparin cofactor, antithrombin-III (AT-III), compromises the efficacy of heparin in the setting of pharmacologic fibrinolysis and, if so, whether this degradation or inactivation is directly attributable to the effects of tissue-type plasminogen activator (t-PA) or plasmin in the blood stream.

METHODS

AT-III was assayed by Western blotting and with a microlatex particle immunoassay in buffer, plasma, or in vivo after exposure to plasmin or t-PA.

RESULTS

Neither t-PA (1-10 micrograms/ml) nor plasmin (2 microM) appeared directly to degrade AT-III in purified systems or in plasma. However, levels fell in some patients treated with t-PA, albeit a minority, in association with intense thrombosis, as reflected by failure of recanalization.

CONCLUSION

Our results demonstrate that AT-III is not degraded directly by t-PA or plasmin. They suggest that intense, ongoing thrombosis is responsible for consumption of AT-III in some patients and support the hypothesis that diminution of AT-III is a manifestation rather than a cause of inadequate anticoagulation.

Asparagine-linked carbohydrate of Penicillium notatum phospholipase B

The asparagine-linked sugar chains of phospholipase B from Penicillium notatum were released by hydrazinolysis. The carbohydrate components were re-N-acetylated and then reductively aminated with 2-aminopyridine. The pyridyl-aminated derivatives were analyzed by size-fractionation and reverse-phase HPLC. The results indicated that the enzyme contains only one kind of oligosaccharide. The carbohydrate was purified by HPLC, and then subjected to NMR and MS analyses for determination of its structure. Based on the results, the structure was determined to be as follows. [sequence: see text]

Inhibition of type-1 plasminogen activator inhibitor production by antisense oligonucleotides in human vascular endothelial and smooth muscle cells

We have hypothesized that type-1 plasminogen activator inhibitor (PAI-1) may exacerbate accumulation of extracellular matrix in atheroma by inhibiting local generation of plasmin and intramural proteolysis. Thus, suppression of PAI-1 expression would decrease atherogenesis. To inhibit expression of PAI-1 in cultured human umbilical vein endothelial and aortic smooth muscle cells, a 20-base antisense phosphorothioate oligonucleotide targeting specific sequences in the 3'-untranslated region of the PAI-1 gene was used. Studies with 32P-labeled oligomers verified stability in media. Secretion of PAI-1 protein assayed by enzyme-linked immunosorbent assay declined specifically and dose-dependently in cells exposed to the antisense oligonucleotide treated under basal conditions and after stimulation of PAI-1 expression with transforming growth factor beta (0.5 ng/ml for endothelial cell, 5 ng/ml for smooth muscle cell). Inhibition of expression was confirmed by immunoprecipitation of 35S-labeled PAI-1 and was paralleled by decreased steady-state levels of PAI-1 mRNA (Northern blots). Decreased PAI-1 synthesis was accompanied by augmentation of cell-associated plasmin activity. Thus, the antisense oligonucleotide down-regulated PAI-1 elaboration, an approach that may be useful in limiting obstructive vascular lesions.

Neural-network laser radar

A laser radar whose resolution is greater than 1 µm is reported. We present the radar results when they are used for such purposes as determining the size of a void inside a silicon wafer, profiling a cross-sectional pattern of an optical fiber, studying the birefringence of a lithium-niobate crystal, or finding a fault in an optical guide in an optical integrated-circuit wafer. Neural-network theory was used in processing the radar signal. Radar processing based on neural-network theory gave significantly superior resolution compared with Fourier-transform-based processing.

Distribution of substance P-containing and catecholaminergic nerve fibers in the rabbit carotid body: an immunohistochemical study in combination with catecholamine fluorescent histochemistry

The distribution of substance P (SP)-immunoreactive nerve fibers in the rabbit carotid body was studied in combination with catecholamine autofluorescence images of sections where SP immunoreactivity was confirmed. Immunoreactivity for SP was found in nerve fibers distributed in the parenchyma of the carotid body. No glomus cells with SP immunoreactivity were observed in the carotid body. On comparing the distribution of SP-immunoreactive fibers with the catecholamine autofluorescence image in a single section, most SP fibers appeared associated with the fluorescent glomus cells, and were located around clusters of them. These results support the suggestion that SP fibers in the cat and rat carotid bodies are involved in chemosensory mechanisms. Furthermore, a survey of the present results and previous ones reported by other workers indicates that SP may be an essential neuropeptide in chemoreceptor organs in most vertebrates from amphibians on upwards evolutionally. In addition, the courses of some catecholaminergic fibers precisely agreed with those of some SP fibers. This suggests that certain sympathetic nerve fibers also contain SP.

Effects of single or repeated administration of a carbamate, propoxur, and an organophosphate, DDVP, on jejunal cholinergic activities and contractile responses in rats

Wistar rats were injected once or repeatedly for 10 days with dichlorvos (DDVP, 5 mg kg-1), propoxur (10 mg kg-1), oxotremorine (0.1 mg kg-1) or atropine (5 mg kg-1). Animals were killed 20 min or 24 h after single or consecutive injections, respectively, for determinations of cholinergic activities and contractile responses to acetylcholine (ACh) of the jejunum. Single treatments: while DDVP and propoxur decreased acetylcholinesterase (AChE) activity, oxotremorine and atropine did not. Although DDVP, propoxur and oxotremorine increased levels of ACh, atropine decreased them. Contractile responses to ACh were enhanced by DDVP and reduced by oxotremorine and atropine. The Bmax value of binding of [3H]quinuclidinyl benzylate (QNB) to muscarinic ACh receptors was decreased by atropine. Consecutive treatments: DDVP and oxotremorine decreased AChE activity markedly and slightly, respectively. Although DDVP and oxotremorine increased levels of ACh, propoxur decreased them. Without affecting the contractile responses, DDVP caused a reduction and propoxur and atropine caused an increase in the Bmax value for binding of [3H]QNB. Both the contractile responses and the value of Bmax for binding of [3H]-QNB were decreased by oxotremorine. In summary, propoxur and DDVP showed similar effects mainly through their anticholinesterase properties in the case of single injection, but DDVP had similar effects to those of oxotremorine and propoxur had similar effects to those of atropine in the case of repeated injection.

Transitional cell carcinoma of the fallopian tube: a light and electron microscopic study

Carcinomas other than adenocarcinomas are extremely rare in the fallopian tube. We report a case of a malignant neoplasm of the fallopian tube with histological features of transitional cell carcinoma that presumably arose from an extraluminal region of the tube. A 57-year-old postmenopausal woman with vaginal bleeding was found to have a left adnexal tumor. Exploratory laparotomy revealed a left tubal tumor with a metastatic nodule on the rectal surface. Histologically, the tumor surrounded the lumen of the left fallopian tube and was composed of cells with "coffee-bean"-like nuclei arranged in solid nests without keratinization. No abnormalities were found in the right tube, ovaries, or uterus. Electron microscopy revealed the tumor cells to have nuclei with deep nuclear indentations, cytoplasmic tonofilaments, and intercellular spaces with prominent interdigitations of the cell membrane. In addition, several tumor cells with protruding microvilli formed abortive lumina. These histological and ultrastructural features were consistent with the diagnosis of transitional cell carcinoma.

[A case report of coronary artery bypass grafting surgery with aprotinin in a patient undergoing chronic haemodialysis]

A 61-year-old patient who was receiving haemodialysis because of chronic renal failure developed unstable angina pectoris with three vessel disease. We performed successful coronary artery bypass grafting, using aprotinin to reduce blood loss. Blood loss during the operation was 750 ml, and during a 6 hour period after the operation it was 150 ml. This amount seemed to be small. No adverse clinical effects attributable to aprotinin were seen, and urine volume and plasma creatinine were not different before and after the operation. In summary, aprotinin is useful adjunct to open heart surgery in chronic haemodialysis patients.

[Clinical significance of endocervical curettage (ECC) in predicting neoplastic lesions of the cervix]

Endocervical curettage (ECC) was routinely performed at the time of colposcopy on 200 cases with an abnormal PAP smear. Colposcopically, 77 cases were normal, 99 were abnormal, and 24 were unsatisfactory. Results of the directed biopsies were within normal limits for 84 cases, glandular dysplasia for 2, squamous dysplasia for 95, carcinoma in situ (CIS) for 17, and squamous cell carcinoma for 3. Histologic diagnoses of the ECC specimens were "tissue insufficient for diagnosis" for 11 cases, "benign endocervical tissue" for 167 including 9 squamous metaplasias and 3 cervical polyps, "fragments of dysplasia" for 12, CIS for 6, and squamous carcinoma for 4. Regarding 73 cases who underwent surgical treatment, the biopsy diagnosis had been either false negative in 6 cases or underestimated in 5 cases as compared to the confirmed diagnosis. That is to say, 11 cases might have been diagnosed incorrectly without ECC. The major lesion was located within the endocervix in most of such cases. It is therefore suggested that ECC improves the accuracy of the histologic diagnosis of premalignant and malignant lesions of the cervix and that ECC is an essential procedure especially in endocervical lesions.

Augmented systemic immunity in mice implanted with tumor necrosis factor-alpha gene-transduced Meth-A-cells

Syngeneic BALB/c mice bearing methylcholanthrene-induced fibrosarcoma (Meth-A) cells transduced with a tumor necrosis factor (TNF) gene showed a longer life span and tumor regression as compared with mice carrying TNF-non-producing Meth-A cells. To elucidate the mechanism of the reduced tumorigenicity of TNF-producing Meth-A, we compared systemic immune responses between mice bearing high TNF producer (C5) and unmodified Meth-A cells (M0). The results indicated that the cytotoxic activity of lymphokine-activated killer cells (LAK) induced from spleen cells of mice bearing C5 was higher against both M0 and C5 than that of LAK from mice bearing M0. Also, C5 was more sensitive to LAK induced from spleen cells of C5- and M0- bearing mice than M0. We also found that cytotoxic T lymphocyte from spleen cells of mice transplanted with C5 was more cytotoxic to M0 than that from mice with M0. In addition, the population of Lyt2 (CD8)-positive T cells was higher in freshly isolated spleen cells of mice transplanted with C5 than from mice with M0. Finally, we observed a higher expression of MHC class 1 antigen on C5 than on M0. These observations suggest that the augmented host systemic immunity in mice carrying TNF gene-modified Meth-A cells is one of the mechanisms of the reduced tumorigenicity of C5 and that the increased systemic immunity can be ascribed to the increased immunogenicity of the tumor cells. Thus, the use of TNF gene-modified tumor cells as vaccines appears to be promising for therapeutic and/or prophylactic application.

Wrap-clipping with a Dacron mesh silastic sheet. Technical note

A technique combining wrapping and clipping using a Silastic sheet coated with Dacron mesh is described for treatment of fusiform or broad-based cerebral aneurysms. This sheet is easily tailored to wrapping the aneurysm base while avoiding involvement of the cranial nerves or branching vessels. The sheet is semitransparent so that the caliber of the newly constructed parent artery is easily adjusted during wrap-clipping. After the aneurysm and the parent artery have been circumferentially wrapped with the sheet, aneurysm clips are applied on the sheet so that the base of the aneurysm is clipped between the two leaves of the sheet. This wrap-clipping technique avoids the risks involved in extracting the aneurysm from the parent artery. The Dacron mesh coating the outer surface and sufficient clip closing pressure are both helpful in preventing the clip blades from sliding. Similar previously reported techniques are reviewed and discussed in detail.

Characterization of CA125 glycoprotein using 3 monoclonal antibodies with different specificities

CA125 and CA130 in various tissues were characterized using the monoclonal antibodies OC125, 130-22, and 145-9. CA125 and CA130 were eluted in the same fraction in 130-22 affinity chromatography. A sandwich immunoradiometric assay using these antibodies in combination was established. When the solid phase of the assay was changed from OC125 to 145-9, the amount of 125I-OC125 that reacted with CA125 in the amnion increased more than that in other samples. On SDS-PAGE, CA125 and CA130 epitopes in the amnion migrated to different positions. These results indicate that CA125 and CA130 are located on different subunits of the same glycoprotein, and that their synthesis is regulated differently in various tissues.

A multi-centre study of the efficacy and safety of pravastatin in hypercholesterolaemic patients with non-insulin-dependent diabetes mellitus

A multi-centre, non-randomized clinical study of 12-months' duration was performed in 112 patients with hyperlipidaemia associated with non-insulin-dependent diabetes mellitus to evaluate the clinical efficacy and tolerability of pravastatin and to assess its effect on glycaemic control. Patients were eligible for this trial if they fulfilled the following criteria; a high plasma total cholesterol level greater than 220 mg/dl associated with stable glycaemic control for at least 3-months' observation period. On entry, patients received 10 mg pravastatin per day (5 mg twice daily) for 12 months. Clinical efficacy was evaluated in 108 patients. The results showed that pravastatin induced a significant decrease in serum cholesterol level mainly with LDL-cholesterol. Total cholesterol levels were decreased significantly from 275 +/- 3 mg/dl to 222 +/- 4 mg/dl within 3 months of the start of treatment, and LDL-cholesterol decreased from 192 +/- 4 mg/dl to 137 +/- 4 mg/dl. After 12 months' treatment, total cholesterol and LDL-cholesterol levels were 216 +/- 4 mg/dl (p < 0.001) and 137 +/- 5 mg/dl (p < 0.001), respectively. HDL-cholesterol levels were increased from 51 +/- 2 mg/dl to 56 +/- 2 mg/dl at 3 months (p < 0.001) and 55 +/- 2 mg/dl at 12 months (p < 0.01). Triglyceride concentrations were also decreased from 173 +/- 11 mg/dl to 156 +/- 13 mg/dl at 3 months and 137 +/- 10 mg/dl at 12 months (p < 0.01). Fasting plasma glucose and glycated haemoglobin levels were not affected by pravastatin. Adverse events observed in 5 cases were always mild and reversible. These results indicate a clinical usefulness of pravastatin with high compliance in patients with hyperlipidaemia associated with non-insulin-dependent diabetes mellitus.

Regulation of renal cytochrome P450s by thyroid hormone in diabetic rats

Effects of thyroid hormone treatment on renal P450 expression in the diabetic rats were investigated. Diabetes produced by streptozotocin induced CYP4A2 and P450 K-2 (similar form with CYP2C23) but not P450 K-4 (similar form with CYP4A8) and induced lauric acid hydroxylation activity. The serum thyroid hormone level was decreased with diabetes. Treatment of diabetic rats with thyroid hormone (T3) as well as with insulin reversed the increase in the levels of CYP4A2 and P450 K-2. Thyroidectomy also induced CYP4A2 and P450 K-2 in the rat kidney. The increase was reversed by treatment of thyroidectomized rats with T3. These findings suggest that expression of CYP4A2 and P450 K-2 in rat kidney is suppressively regulated by thyroid hormone and the decrease in thyroid hormone level in the diabetic state affects the levels of CYP4A2 and P450 K-2.

Characterization of the electron acceptors of old yellow enzyme: mechanistic approach to the mode of one electron transfer from the enzyme to menadione or dyestuffs

Molecular oxygen or cytochrome c has been described as the electron acceptor of the reaction of old yellow enzyme with NADPH. In this study, menadione was found to be a sensitive electron acceptor of the reaction under aerobic as well as anaerobic conditions. The Km value of menadione for old yellow enzyme is as low as 2-3 x 10(-7) M in the presence or absence of superoxide dismutase. The rate enhancement of the cytochrome c reduction of old yellow enzyme with NADPH was about eight times in the presence of menadione. The rate increment was slightly higher under aerobic than anaerobic conditions. The rate enhancement by menadione enabled sensitive determination of the enzyme activity in the assay system, which contained NADPH, cytochrome c, menadione, and old yellow enzyme. In the reaction course, the semiquinone species of menadione was trapped by the reaction with t-butyl-alpha-phenylnitrone. The radical adduct was detected on EPR. The dyestuff, 2,6-dichlorophenolindophenol, was found to be reduced ineffectively even in the presence of menadione; moreover, it was inhibitory in the NADPH consumption reaction. Methylene blue or Lauth's violet, known to be capable of semiquinone formation, also behaved, like menadione, as a mediator of electron transport to cytochrome c. On the basis of the experimental results, the occurrence of the one electron transfer of the old yellow enzyme reaction was emphasized.

Role of marginal stress fibers formed in the rat vascular endothelial cells

Fluorescence cytochemistry using en face preparations of rat vascular endothelial cells (ECs) revealed the localization of actin, fibronectin (FN) and fibronectin receptor (FNR) along not only central stress fibers (SFs) but also the cell margins. Electron microscopy showed very close proximity between the topographical distribution of intracellular microfilament bundles and that of subendothelial FN in the EC margins. Therefore, these basal and marginal actin cables may be comparable to the well-established central SFs present in ECs. Formation of the central SFs was induced in ECs or mesothelial cells in response to tension, by which their cellular integrity seems to be effectively maintained. However, even when central SF formation was inhibited by cytochalasin D, the ECs with marginal SFs showed high resistance to mechanical tension, whereas mesenteric mesothelial cells having no such fibers easily lost their integrity. Thus, together with central SFs, the marginal SFs characteristic of rat vascular ECs may play an essential role in strengthening cell-matrix adhesion.

NMR studies of G:A mismatches in oligodeoxyribonucleotide duplexes modelled after ribozymes

The structures of two oligodeoxyribonucleotide duplexes, the base sequences of which were modelled after both a hammerhead ribozyme and a small metalloribozyme, were studied by NMR. Both duplexes contain adjacent G:A mismatches; one has a PyGAPu:PyGAPu sequence and the other a PyGAPy:PuGAPu sequence. It is concluded on the basis of many characteristic NOEs that in both duplexes G:A base pairs are formed in the unique 'sheared' form, where an amino proton instead of an imino proton of G is involved in the hydrogen bonding, and G and A bases are arranged 'side by side' instead of 'head to head'. A photo-CIDNP experiment, which gives unique and independent information on the solvent accessibility of nucleotide bases, also supports G:A base pairing rather than a bulged-out structure of G and A residues. This is the first demonstration that not only the PyGAPu:PyGAPu sequence but also the PyGAPy:PuGAPu sequence can form the unique sheared G:A base pairs. Taking the previous studies on G:A mismatches into account, the idea is suggested that a PyGA:GAPu sequence is a minimum and essential element for the formation of the sheared G:A base pairs. The sheared G:A base pairs in the PyGAPu:PyGAPu sequence are suggested to be more stable than those in the PyGAPy:PuGAPu sequence. This is explained rationally by the idea proposed above.