Structure-activity studies on C-terminal hirudin peptides containing sulfated tyrosine residues

To clarify the role of the negative charge of the C-terminal region of hirudin, we chemically synthesized the C-terminal peptide of hirudin variant-1 (HV-1), HV-1-(54-65), and its analogs, [E61Y,E62Y]HV-1-(54-65) and [E62Y]HV-1-(54-65), and then sulfated the Tyr residue(s) in these peptides by both enzymic and chemical methods. Enzymic O-sulfation of Tyr residues in the peptides by use of sulfotransferase isolated from Eubacterium A-44 allowed us to produce four kinds of the sulfated peptide, whose C-terminal sequences were -PEY(SO₃H)YLQ, -PYY(SO₃H)YLQ, -PYYY(SO₃H)LQ and -PYY(SO₃H)Y(SO₃H)LQ. On the other hand, all Tyr residues in the peptides were successfully sulfated by chemical reaction with N, N′-dicyclohexylcarbodiimide in the presence of sulfuric acid. Based on the analysis of structure-activity relationships of these sulfated peptides for thrombin inhibition, the Tyr62 and Tyr63 bisulfated peptide GDFEEIPEY(SO₃H)Y(SO₃H)LQ was found to be the most potent inhibitor of thrombin among the products tested. No increase in potency was observed by further substitution of Glu61 with Tyr(SO₃H). The inhibitory activity by substitution with Tyr(SO₃H) at position 63 was greater than that obtained by the substitution at position 62. © Munksgaard 1996.     

Ability of inhaled procaterol, a β32 adrenoceptor agonist, to attenuate eicosanoid-induced airflow obstruction and airway microvascular leakage

Beta-2 adrenoceptor agonists are widely used as bronchodilators in the treatment of asthma mainly via inhalation. In the present study, we evaluated the ability of inhaled procaterol, a β2 adrenoceptor agonist, to reduce eicosanoid-induced airway micro-vascular leakage, and compared the ability with its inhibitory effect against bron-choconstriction. Tracheostomized guinea-pigs were given aerosolized procaterol (10 or 100 μg/ml) for 10min under spontaneous breathing. Immediately after the end of inhalation, the animals were mechanically ventilated. Fourteen minutes after the end of inhalation, Evans blue dye (20mg/kg) was given i.v. One minute later, 2nmol/kg leukotriene D4 (LTD4), 50 nmol/kg U-46619, a thromboxane A2 mimetic, or vehicle was administered i.v. LTD4- or U-46619-induced increase in lung resistance was measured for 6 min. After removing the lungs, the amount of extravasated Evans Blue due in the lower airways was examined as an index of microvascular leakage. Inhaled procaterol significantly attenuated increases in both lung resistance and Evans Blue dye extravasation caused by these eicosanoids. The degree of inhibition was almost complete for lung resistance (approximately 90%), but it was only partial (range 18.5–61.2%) for the dye extravasation. No significant changes in mean systemic blood pressure and in heart rate was observed after an inhalation of 10μg/ml procaterol. These results suggest that inhaled β2 adrenoceptor agonists may reduce airway microvascular leakage caused by inflammatory mediators such as eicosanoids without affecting systemic circulation. However, these agonists may attenuate airway microvascular leakage only partially even in doses which can inhibit bronchoconstric-tion almost completely.     

Effect of Chronic Hyperprolactinemia Induced by Sulpiride on Plasma Dehydroepiandrosterone (DHA) in Normal Men

In order to elucidate the relationship between plasma dehydroepiandrosterone (DHA) and sulpiride-induced hyperprolactinemia (of 60 day duration) in normal men, five normal men (aged 27-46) were administered daily 300 mg of sulpiride orally for 60 days to induce hyperprolactinemia. Plasma levels of prolactin, DHA and cortisol were measured by radioimmunoassay before sulpiride treatment, at day 14 and day 60 after initiation of the treatment. Plasma levels of prolactin after the administration rose significantly (P less than 0.001) to 71.6-95.3 ng/ml in four out of the five subjects compared with those of the controls. In the same four subjects the mean DHA values in plasma were elevated significantly (P less than 0.05) to 877 +/- 160 ng/dl from the mean baseline values (669 +/- 91 ng/dl). The elevated values remained during sulpiride treatment. Plasma levels of cortisol did not change significantly during sulpiride administration in all subjects. Our results suggest that sulpiride-induced hyperprolactinemia sustained at least 14-60 days in normal men stimulates the adrenal cortex to secrete DHA.     

RENAL CELL CARCINOMA IN CHILDREN: EXPERIENCE AT A SINGLE INSTITUTION IN JAPAN

PURPOSE: We analyzed the presentation, treatment and survival of 4 children with renal cell carcinoma. MATERIALS AND METHODS: We retrospectively reviewed the pathological and hospital records of 4 Japanese children diagnosed with renal cell carcinoma at our hospital from 1970 to 1998. RESULTS: In the 1 boy and 3 girls with an average age of 8 years 7 months at diagnosis the most common presenting complaints were gross hematuria in 75% and a palpable abdominal mass in 50%. Computerized tomography revealed characteristic calcification within the tumor in 3 of the 4 patients (75%). In the remaining case the lesion had high density areas with microcalcification, as confirmed by histopathological study. In 2 patients with regional lymph node metastasis calcification was also observed in the metastatic lesions. Disease was stages I to III in 1, 1 and 2 patients, respectively. All patients underwent transabdominal nephrectomy with regional lymphadenectomy. One patient with stage I disease had multiple metastases 15 months later and died of disease 55 months postoperatively. However, the remaining 3 patients received adjuvant interferon therapy and they are without evidence of recurrence a mean of 51.3 months postoperatively. CONCLUSIONS: Calcification within the tumor and/or metastatic lesions or high density areas in the tumor on screening computerized tomography are characteristic findings suggestive of pediatric renal cell carcinoma. Adjuvant therapy with interferon may provide some benefit in select pediatric patients. Further studies of a larger number of pediatric renal cell carcinoma cases may be necessary to establish the optimal diagnostic and therapeutic regimen.     

Parkinsonism with multiple cysts in the bilateral striata

The present paper reports on a 68‐year‐old man with a 10‐year history of parkinsonism who developed hallucinations and delusions after admission to an intensive care unit for the treatment of organophosphate intoxication. His initial diagnosis was delirium. On the basis of brain computed tomography findings and clinical symptoms, we diagnosed drug‐induced psychosis in parkinsonism with multiple cysts in the bilateral striata.     

Different pharmacokinetic s of (4R)-hexahydro-7,7- dimethyl-6-oxo-1,2,5-(3-14C)dithiazocine-4-carboxylic acid between the fasting and non-fasting rat: role of intestinal microorganisms

1. We report differences in the pharmacokinetic s of (4R)-hexahydro-7,7-dimethyl-6-oxo-1,2,5-(3-¹⁴C)dithiazocine-4-carboxylic acid (¹⁴C-SA3443) between the normal fasting and non-fasting rat, especially in the blood concentration-t ime curves and respiratory excretion. Exhalation of ¹⁴CO₂ was an important route of elimination and accounted for 21.2% of the dose in the non-fasting rat but only 3.7% in fasting animals. 2. In the intestinal microorganism-compromised rat, we found little differences in the pharmacokinetics of C-SA3443 between fasting and non-fasting states. No respiratory excretion was observed in the intestinal microorganism-compromised animal. 3. In the reaction mixture of ¹⁴C-SA3443 with the cecal contents of rat, ¹⁴C-acetic acid and ¹⁴C-butyric acid were detected and ¹⁴CO₂ barely detected. 4. The amounts of ¹⁴C-acetic acid and ¹⁴C-butyric acid in the reaction mixture of ¹⁴C-SA3443 with non-fasting rat cecal contents were more than those with fasting rat cecal contents. 5. We concluded that the reason for the different pharmacokinetics of ¹⁴C-SA3443 between the fasting and non-fasting rat was the differences in participation of the metabolism of ¹⁴C-SA3443 by intestinal microorganisms.     

Percutaneous central venous catheterization via the great saphenous vein in neonates

In 44 neonates (mean birthweight 1207 g and mean gestational age 30.0 weeks), very small central venous catheters were percutaneously inserted via the great saphenous vein on 46 occasions. Catheter-related complications such as catheter blockages in 17 (37%), edema in a unilateral leg in three (6%), and mechanical disruption in two (4%) were noted. Although two of the neonates were found to have bacteremia and five neonates died, none were catheter related. The optimal length of catheter insertion (Y) from the great saphenous vein at the level of the medial maleollus to the inferior vena cava at T9 and L3 was calculated by regression equations utilizing total body length (X). Radiographs taken with extended and flexed leg postures revealed that the catheter tips were retracted with extension of the lower extremities and the degree of displacement ranged from 1 to 4 (mean 2.7) vertebral levels. Because this movement might cause migration into veins that connect to the inferior vena cava, the catheter tip should be located between T9 and L3, except at the renal vein junction. Percutaneous central venous catheterization via the great saphenous vein is safe and useful. Regression equations provided for rapid estimation of the optimal length of insertion.     

The Role of CD45RA on Human B-Cell Function: Anti-CD45RA Antibody (Anti-2H4) Inhibits the Activation of Resting B Cells and Antibody Production of Activated B Cells Independently in Humans

Anti-CD45RA antibody defined by anti-2H4 monoclonal antibody has been reported to split CD4+T cells into two distinct subpopulations. CD45RA antigen is present on the surface of virtually more than 95% B lymphocytes in the purified tonsillar B-cell preparations. We examined the role of CD45RA antigen on human B-cell function using this antibody. The addition to anti-2H4 to tonsillar B cells inhibited the proliferative response induced by Staphylococcus aureus Cowan strain I(SAC) in a dose-dependent manner. Kinetic analysis indicated that anti-2H4 exerted its inhibitory effect when added within the first 24 h of culture initiation during a 72-h culture period. Anti-2H4 inhibited the transferrin receptor expression without interfering with the expression of the IL-2 receptor on SAC-stimulated B cells in a short-term culture. Anti-2H4 blocked the progress of SAC-stimulated B cells from the G1 to S phase of the cell cycle. These events suggested that anti-CD45RA MoAb inhibited the proliferative response by directly acting on B cells in the G1 phase. In addition, anti-CD45RA antibody also had a suppressive effect on early phase of B-cell differentiation. This effect appeared to be independent of its suppressive effect on proliferation, because anti-CD45RA did not inhibit the proliferative response of preactivated B cells with lymphokines. These studies suggested that the restricted epitope recognized by anti-2H4 antibody may be directly involved in regulatory function on B cells.     

Ultrastructure of intramural ganglia in the striated muscle portions of the guinea pig oesophagus

The ultrastructure of the myenteric plexus located in the striated muscle portion of the guinea pig oesophagus was examined and compared with that of the plexus associated with the smooth muscle portion of the rest of the digestive tract. The oesophageal ganglia had essentially the same architecture as those of the smooth muscle portion, such as a compact neuropil without the intervention of connective tissue and blood vessels. Some features, however, were particular to the striated muscle part of the oesophagus. It was clearly demonstrated that myelinated fibres, probably sensory terminals of vagal origin, join the myenteric ganglia. Synapses and terminal varicosities are sparsely distributed within the ganglia and fewer morphological types of axon varicosities could be distinguished compared with other regions. Glial cells are well developed in the oesophageal myenteric ganglia. These cells outnumber the ganglion cells, having a higher ratio than in the lower digestive tract, and form numerous cytoplasmic lamellar processes. The lamellar processes, located at the surface of the ganglia, considerably reduce the area of neuronal membrane which directly contacts the basal lamina. The role of these lamellar processes in the oesophageal ganglia is discussed.