STUDIES ON RACEMIZATION DURING COUPLINGS USING A SERIES OF MODEL TRIPEPTIDES INVOLVING ACTIVATED RESIDUES WITH UNFUNCTIONALIZED SIDE CHAINS

Racemization studies have been carried out using as model tests couplings of N-benzyloxycarbonylglycyl-l -χ with benzyl N^e-benzyloxycarbonyl-l -lysinate followed by deprotection and analysis for the diastereomeric tripeptides with an amino acid analyzer, for χ = alanine, leucine, phenylalanine, valine and isoleucine. The order of susceptibility to racemization of residues during these segment couplings depends on whether the solvent is polar or apolar, with isoleucyl and valyl, followed by phenylalanyl, being the most susceptible ones in polar solvents. The racemization depressing effect of some additives on carbodiimide-mediated couplings has been examined. Reconciliation of apparent discrepancies in data in the literature on the relative merits of l-hydroxy-benzotriazole and N-hydroxysuccinimide is made on the basis of the nature of the model tests used in acquiring the data.     

Certain type of chronic lung disease of newborns is associated with Ureaplasma urealyticum infection in utero

BACKGROUND: Recent studies of chronic lung disease (CLD) of newborns emphasize the contribution of antenatal infection. However, the association of Ureaplasma urealyticum infection and CLD has been controversial. The purpose of the present paper was to determine whether U. urealyticum is associated with chorioamnionitis (CAM) and a certain type of CLD. METHODS: One hundred and five infants <32 weeks of gestation who were admitted to the neonatal intensive care unit at Jichi Medical School Hospital, who underwent both histological and microbiological examinations and who survived to discharge were included. CAM was determined by histological examination. Placenta, gastric and tracheal aspirates, and nasopharyngeal swabs were cultured for Mycoplasma and other microorganisms. CLD was defined as oxygen needed at 28 days of age with symptoms of persistent respiratory distress and hazy or emphysematous and fibrous appearance upon X-ray. CLD was further divided into two subtypes according to the presence of antenatal infection. RESULTS: CAM was associated with premature rupture of membrane (odds ratio [OR], 10.19; 95% confidence interval [CI]: 3.10-33.56), placental colonization of U. urealyticum (OR 6.73, 95%CI: 1.89-23.91), neonatal colonization of other microorganisms (OR 7.33, 95%CI: 1.22-44.13) and level of IgM (OR 1.06, 95%CI: 1.01-1.11). Comparisons between CLD and non-CLD patients showed that gestational age (OR 0.43, 95%CI: 0.30-0.61) and white blood cell count (WBC) at birth (OR 1.06, 95%CI: 1.01-1.11) were risk factors for CLD, while gestational age (OR 0.38, 95%CI: 0.23-0.64), neonatal colonization of U. urealyticum (OR 5.98, 95%CI: 1.17-30.6) and WBC (OR 1.08, 95%CI: 1.01-1.15) were independent risk factors for infection-related CLD compared with non-CLD. Within CLD, infection-related CLD was associated with neonatal colonization of U. urealyticum (OR 43.7, 95%CI: 2.84-673.8) and WBC (OR 1.27, 95%CI: 1.07-1.50). CONCLUSIONS: Placental colonization of U. urealyticum was significantly related to CAM; and neonatal colonization of U. urealyticum and leukocytosis at birth were risk factors for infection-related CLD.     

Epidemiology of school urinary screening over a 30 year period in Tokyo

BACKGROUND: A school urinary screening (SUS) system has been conducted for 30 years in Japan, but the cross-sectional data have never been reported or analyzed. The purpose of the present study was to analyze the data epidemiologically. METHODS: All elementary and junior high school children in public school in Tokyo who had SUS performed by the Tokyo Health Service Association from 1974 to 2002 (approx. 400,000-600,000 children per year) were involved. The cross-sectional data were analyzed with Pearson's correlation coefficient. RESULTS: During the first 10 years of SUS, the prevalence of abnormal urinalysis in both the first and second screenings varied widely, and the result of the second screening was affected by that of the first screening. The results of both first and second screening were highly correlated with the prevalence of hematuria, especially microhematuria, in both elementary and junior high school children. They were also correlated with the prevalence of proteinuria in junior high school children. Important factors that affected the prevalence of hematuria and/or proteinuria were reagent strips and sampling method of urinalysis. CONCLUSIONS: In order to validate SUS, attention should be paid to quality controls of the screening method, such as the selection of reagent strips, and the participants should be instructed to strictly adhere to the sampling method.     

Lectin-reactive alpha-fetoprotein as a marker for testicular tumor activity

BACKGROUND: Lens culinaris agglutin (LCA)-affinity electrophoresis resolves serum alpha-fetoprotein (AFP) into three isoforms, AFP-L1, -L2 and -L3. The ratio of AFP-L3 to total AFP (AFP-L3%) is frequently high in hepatocellular carcinoma (HCC) patients, and thus, it is widely used for early diagnosis of HCC. In the present study, we used the subfraction profile of LCA-binding AFP to diagnose and monitor testicular tumor activity. METHODS: Serum samples were collected from 21 testicular tumor patients, and the LCA-reactive fractions were determined by LCA-affinity electrophoresis coupled with antibody-affinity blotting. The histological diagnosis was non-seminomatous germ cell tumor (NSGCT) in 15 patients and pure seminoma in six patients. RESULTS: Serum AFP levels were abnormally elevated (>20 ng/mL) in 10 of 15 NSGCT patients. One NSGCT patient and two seminoma patients showed borderline AFP levels between 10 and 20 ng/mL. LCA-reactive AFP was detected in all 11 NSGCT patients with serum AFP levels above 10 ng/mL, but not in the two seminoma patients with serum AFP levels above 10 ng/mL. In testicular tumor patients, the broad band of AFP-L2 could not be completely separated from AFP-L3. The mean ratio of AFP-L3 plus AFP-L2 (AFP-L2 + 3%) was as high as 94% (range 80-99%) in these patients. Serial determinations of LCA-reactive fractions were performed in eight of the 11 LCA-reactive AFP-positive patients. They included five patients who received chemotherapy, and three patients who underwent orchiectomy for stage I NSGCT. In three of eight patients, LCA-reactive AFP was detected even after normalization of total AFP levels. All three patients relapsed, with elevation of serum AFP within several months. CONCLUSION: Determination of LCA-reactive AFP might be a useful marker for testicular tumor activity in patients with lower AFP levels.     

A case of four coronary artery fistulae originating from three vessels associated with aneurysm

A case of an aneurysm associated with four coronary artery fistulaeoriginating from three vessels is reported. The patient, a 52-year-oldwoman, had chest heaviness and palpitations. Coronary arteriographyreveaed the four fistulae originating from three coronary vesselswith an aneurysm draining into the left ventricle and the mainpulmonary artery.The patient's symptoms were relieved afterfistulectomy and the aneurysmectomy, suggesting that a coronarysteal phenomenon through the fistulae was the cause of her symptoms.This case is of interest because of its rarity, since this isthe first case report of an aneurysm associated with four coronaryartery fistulae from three vessels.     

Very high doses of valsartan provide renoprotection independently of blood pressure in a type 2 diabetic nephropathy rat model

Aim:   Angiotensin II type 1 receptor blockers (ARB) retard the progression of hypertensive diabetic kidney disease. Clinical evidence suggests that the dose of ARB required to correct hypertension is suboptimal for renoprotection evaluated by proteinuria. No systematic, prospective study has yet evaluated separately the effect of increasing doses of ARB on blood pressure and proteinuria.
Methods:   Over a period of 8 weeks, the effect of seven constant doses of an ARB, valsartan (4–160 mg/kg per day), on blood pressure and proteinuria taken as a surrogate marker of nephropathy in a hypertensive, type 2 diabetic rat model, the spontaneously hypertensive/NIH-corpulent rat (SHR/NDmcr-cp), was assessed. In this spontaneously hypertensive rat strain, a genetic mutation in the leptin receptor gene is associated with hyperphagia leading to obesity with metabolic syndrome and eventually to nephropathy.
Results:   No additional blood pressure lowering was observed above 120 mg/kg per day of valsartan, suggesting that a dose of 80–120 mg/kg per day had a maximal effect. Nevertheless, higher doses of valsartan further reduced proteinuria in a dose-dependent fashion suggesting the absence of a maximal dose. Obesity, hyperglycaemia and hypercholesterolaemia were unaffected but hypertriglyceridaemia was partially corrected at various ARB doses.
Conclusion:   ARB improve renoprotection at doses above those required for a maximal effect on blood pressure. The mechanism of the renoprotection obtained at high doses of ARB is yet to be elucidated.     

Selective effector mechanisms for the expulsion of intestinal helminths

In the middle of the era of molecular biology, much less attention is paid to in vivo phenomena. However, carefully designed experimental systems in vivo still can provide valuable information as to the mechanisms underlying the establishment and maintenance of host-parasite relationships. In this review we describe the advantage of using concurrent infections with appropriately chosen combinations of different genera or different maturation stages of parasites to segregate the cellular responses of the host. By means of simple experimental approaches we have found that mucosal mast cells and goblet cells, both of which have long been considered as non-specific effectors, are in fact highly selective and specific effector cells of the host defence mechanisms capable of acting on the establishment and the expulsion of intestinal helminths.     

Conformation of tetragastrin in DMSO

A conformation analysis of tetrapeptide in DMSO was carried out by the Monte Carlo simulation including the solvent effect in the energy function. The lowest energy conformations in the zwitterionic and cationic states are a similar compact form, in which the two aromatic rings are close to each other. The distance distributions between the specified atoms in the molecule show that most conformations in the local energy minima are similar to this folded conformation, although there is another type of conformation of interest, which has an extended form with the two separate aromatic rings. Such results are consistent with the NMR and CD experiments, and suggest that the compact form of tetragastrin is essential as a biological active conformation. The folded structure is stabilized by the solute-solvent interaction. In particular, the non-bonding interactions between the solute and solvent molecules cause a folding effect on the molecular conformation in total. This study is a first case taking account of the solvent effect into the conformation analysis of tetragastrin.