Increased intraplatelet and urinary transforming growth factor-beta in patients with multiple myeloma

The concentrations of transforming growth factor-beta (TGF-beta) in platelets, plasma and urine from 27 patients with multiple myeloma (MM) and from 22 normal controls were measured by sandwich enzyme-linked immunosorbent assay using a monoclonal antibody specific for human TGF-beta 1+2+3. A significantly increased intraplatelet TGF-beta (24.6 +/- 9.6 vs. 17.8 +/- 8.8 ng/10(5) platelets, p < 0.01) and urinary TGF-beta (1.4 +/- 0.8 vs 1.0 +/- 0.4 ng/mg Cr, p < 0.02) were observed in MM patients compared with normal controls. The mean platelet TGF-beta level in MM patients with osteolytic lesions was more increased than in those without osteolytic lesions (29.6 +/- 7.7 vs 18.4 +/- 8.2 ng/10(5) platelets, p < 0.001). In this study, we evaluated the possible role of TGF-beta in the pathogenesis of myeloma, especially in osteolytic lesions.

Epidemiology of Norwalk virus during an outbreak of acute gastroenteritis aboard a US aircraft carrier

A large outbreak of acute gastroenteritis occurred over a 5-week period aboard an aircraft carrier. The estimated cumulative attack rate was 13% among the 4,500-man crew. Eight percent of the crew sought medical attention, nearly all of whom missed 1 day or more of work. The risk of developing illness was 2 to 3 times greater for individuals living in more crowded sleeping quarters (> 50 persons per compartment). Occurrence of gastroenteritis was associated with a fourfold or more rise in Norwalk virus antibody levels, as measured by an enzyme-linked immunoassay utilizing a baculovirus expressed recombinant antigen. In addition, 27 nm Norwalk virus-like particles were visualized in two of six stools examined by immune electron microscopy. The presence of a low (< 1:50) or a high (> or = 1:6,400) pre-illness antibody level was associated with a lower incidence of illness. This investigation indicates that Norwalk virus can adversely impact operations of a military vessel and that crowding is a major risk factor in transmission.

Tilted amides in amino acid and peptide derivatives

BACKGROUND

Amide bonds in peptides and proteins typically adopt planar cis or trans conformations. Conversions between cis and trans amide conformations are necessary for protein folding and for many other processes, but are difficult to achieve since they involve disruption of the planarity of the bond. As a first step to understanding cis-trans isomerization, we set out to synthesize and characterize peptides that mimic the tilted or twisted amide structures that are postulated to form the intermediate states in this process.

RESULTS

We have synthesized a model amino acid and four dipeptide derivatives containing a methyl-substituted aziridine residue. Single crystals of phenacyl (2R, 3R)-benzyloxycarbonyl-3-methyl-2-aziridinecarboxylate and phenacyl (2R, 3R)-acetyl-glycyl-3-methyl-2-aziridine-carboxylate were obtained. Using X-ray diffraction analysis, we determined that the amide nitrogens of the aziridine rings have tetrahedral sp3-like geometry with tilt angles in the range of 37-38 degrees. The 13C-NMR spectra indicate that the amide carbonyl is dramatically shifted downfield as a consequence of the tilt.

CONCLUSIONS

In peptides containing a substituted aziridine ring, the orbitals of the amide nitrogen are constrained into a tilted configuration. These peptides may mimic the transition state between cis and trans amide conformations. This technique thus provides a novel strategy for the study of isomerization and other biorecognition processes.

[The observation of the bulbar conjunctival microcirculation in patients with retinitis pigmentosa]

The detection of the bulbar conjunctival microcirculation (BCM) of 73 cases (146 eyes) with retinitis pigmentosa (RP) showed that there were some abnormal changes of BCM in the pathologic progress of RP. The older the patient, the longer the disease history and the more the loss of visual field, the more serious the abnormal changes of BCM. The disease in male patients was in general more serious than in female patients. Its characteristics were the followings: increase in the number of tortuous vessels; the different widths of vessels in a few cases; obvious increase of microangioma; abnormal proportion of artery to vein; decelerated blood flow and aggregated erythrocytes. Some abnormal changes in the nailfold microcirculation (left ring finger) were observed in the meantime, and compared with those in the BCM of 56 cases. It was found that they were positively interrelated (gamma's = 0.9965, P < 0.001).

Phosphorylation, high ionic strength, and calmodulin reverse the binding of MARCKS to phospholipid vesicles

The myristoylated alanine-rich protein kinase C substrate (MARCKS) is a major cellular substrate of protein kinase C (PKC), and PKC phosphorylation produces translocation of MARCKS from membrane to cytoplasm in many cells. Our working hypothesis is that binding of MARCKS to biological membranes requires both hydrophobic insertion of its myristoyl chain into the lipid bilayer and electrostatic interaction of its basic domain with acidic lipids. We tested this hypothesis by measuring the binding of murine MARCKS to large unilamellar phospholipid vesicles (LUVs). We estimated the partition coefficient of the myristoyl moiety of MARCKS (KH) by measuring the binding of MARCKS to electrically neutral LUVs (KH = 3 x 10(3) M-1). We examined the effect of electrostatic interactions by measuring the binding of MARCKS to LUVs containing 20% acidic lipid and obtained four results. First, incorporating 20% acidic lipid into the LUVs increased binding of MARCKS about 100-fold. Second, PKC phosphorylation, which added 3 negatively charged phosphate groups to the basic domain, reduced 20-fold the binding of MARCKS to these negatively charged vesicles. Third, increasing the KCl concentration from 0.1 to 0.5 M reduced the binding 15-fold. Fourth, Ca(2+)-calmodulin reduced the binding 20-fold. We present a simple theoretical model that explains these results, which are all consistent with the working hypothesis.

Transformation of lupus-inducing drugs to cytotoxic products by activated neutrophils

Drug-induced lupus is a serious side effect of certain medications, but the chemical features that confer this property and the underlying pathogenesis are puzzling. Prototypes of all six therapeutic classes of lupus-inducing drugs were highly cytotoxic only in the presence of activated neutrophils. Removal of extracellular hydrogen peroxide before, but not after, exposure of the drug to activated neutrophils prevented cytotoxicity. Neutrophil-dependent cytotoxicity required the enzymatic action of myeloperoxidase, resulting in the chemical transformation of the drug to a reactive product. The capacity of drugs to serve as myeloperoxidase substrates in vitro was associated with the ability to induce lupus in vivo.

Changes in gene expression of AMPA-selective glutamate receptor subunits induced by status epilepticus in rat brain

In the present investigation we address the question of whether one of the responses to increased neuronal activity is a modification of the expression of the different subunits of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)-selective glutamate receptors (GluR-1, GluR-2, GluR-3). Thus, we used two different models of generalized status epilepticus, as widespread elevated neuronal activity, to study in vivo responses of the AMPA receptor mRNA expression in rat forebrain. By Northern blot analysis and in situ hybridization, we show that one of the delayed responses to LiCl/pilocarpine-induced status epilepticus is a dramatic change in the mRNA level of some subunits of AMPA-selective glutamate receptors. These effects, which appear between 6 and 12 h after the drug treatment, are subunit and brain region specific. The most striking example of differential expression of the three examined GluR mRNAs can be observed in the dentate gyrus of the hippocampus. In this specific brain subregion an increase of GluR-3 mRNA level is induced 12 h after LiCl/pilocarpine treatment, while a clear decrease in GluR-1 mRNA level and no significant change in GluR-2 mRNA level can be observed in the same area under these experimental conditions. Both the GluR-1 decrease and the GluR-3 increase are transient effects and a return to basal level can be observed after 48-72 h. In the CA1 layer of the hippocampus, a parallel decrease of both GluR-1 and GluR-3 expression is found 12-24 h after drug treatment, followed by a recovery of the expression to control values at 48 h. In kainate-induced epilepsy we could reproduce the late increase (12-24 h) in GluR-3 mRNA in the dentate gyrus; however, under this experimental condition, no clear decrease of GluR-1 expression can be observed in this area. A general decrease in mRNA level for the AMPA receptor subunits (GluR-1-3) in the hippocampal layers, in particular in CA3 and CA4 subfields, was also observed. In conclusion the results reported in the present paper reveal a specific regulation of GluR gene expression in the granule cells of the hippocampal dentate gyrus and stimulate further investigation on the functional role of the GluR-3 subunit in the receptor-channel complex.

Sequence diversity of small, round-structured viruses in the Norwalk virus group

We have determined the nucleotide sequences of a highly conserved region of the RNA-dependent RNA polymerase of the prototype Snow Mountain agent (SMA) and of four other small, round-structured viruses (antigenically Norwalk virus [NV]-like or SMA-like) following reverse transcription-PCR amplification of viral RNA obtained from human stools. The stool samples were either from volunteers administered SMA or from sporadic cases and outbreaks of gastroenteritis that occurred in Japan and the United Kingdom between 1984 and 1992. The GLPSG and YGDD RNA polymerase motifs were in the proper locations in the sequences of the five SRSVs, but each sequence was distinct from the 8FIIa prototype NV sequence and from each other. Analysis of the sequences and reactivities in a new NV antigen enzyme-linked immunosorbent assay showed that the five viruses could be divided into two groups (serogroups) with NV and SMA, respectively, being the prototypes. The sequences of the capsid region and a nonstructural region (2C) were determined from one strain from each group. One virus (SRSV-KY-89/89/J), isolated in Japan and antigenically similar to the prototype NV (isolated 21 years earlier in Ohio), showed a remarkable level of sequence similarity to NV. KY-89 and the 8FIIa NV showed 87.2% nucleotide similarity over 2,516 continuous nucleotides amounting to 96 to 98.9% amino acid similarity in three distinct domains in two open reading frames. Between the prototype SMA and NV, the polymerase region showed 63% nucleotide and 59% amino acid similarity, respectively. Two other antigenically SMA-like isolates (SRSV-925/92/UK and SRSV-OTH-25/89/J), from the United Kingdom and Japan, showed 80% nucleotide and 88 to 92% amino acid similarity in the polymerase region to the prototype SMA isolated 16 and 13 years earlier in the United States. The capsid region of the antigenically SMA-like OTH-25 virus showed 53% nucleotide and 65% amino acid similarity to the prototype NV capsid region. Domains of sequence diversity and conversation were identified within the capsid protein of these two distinct prototype serotypes of virus. These results indicate that NV-like and SMA-like agents are still circulating, and sequence comparisons will be useful to identify and classify distinct viruses in the NV group.

Microalbuminuria in young adults related to blood pressure in a biracial (black-white) population. The Bogalusa Heart Study

The association between microalbuminuria and blood pressure levels was examined in young white and black adults (n = 1131) aged 19 to 32 years. Urinary ratio of albumin (mg/L) to creatinine (mmol/L) was used as an estimation of urinary albumin excretion. Black men and women compared with their white counterparts had higher levels of blood pressure. Significantly positive correlations between urinary albumin excretion and systolic and diastolic blood pressures were observed in black men (r = 0.20 and r = 0.24, P < .01) and black women (r = 0.15 and r = 0.14, P < .05). Similar correlations of significance were not seen in the white counterparts. Systolic and diastolic blood pressure levels were significantly higher in normotensive black subjects (< 140/90 mm Hg) with increased urinary albumin excretion (> or = 90th percentile) than in those without increased urinary albumin excretion. After accounting for potential confounding by age, sex, and body mass index, blacks in the uppermost systolic and diastolic blood pressure group were 7.1 times (95% CI, 2.0 to 25.8) and 4.8 times (1.3 to 18.3), respectively, as likely to have elevated albumin/creatinine excretion as those in the lowest group. In contrast, the likelihood for elevated albumin/creatinine excretion were 0.9 times (95% CI, 0.5 to 2.2) and 1.1 times (0.5 to 2.3), respectively, in whites, which were not significant. These data suggest that a stronger association between blood pressure levels and urinary albumin excretion exists in young blacks than in whites, which supports the notion that blacks may be more susceptible to renal damage from relatively low levels of blood pressure increases.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure changes and hormonal contraceptives

The effects of low-estrogen and progestogen-only contraceptives on blood pressure changes were investigated on 238 women taking 35 micrograms EE OC, 267 using Norplant implants and 259 adopting IUD. The mean increases in diastolic pressure at 12, 24, 36 and 48 weeks among pill users were significantly (p < 0.05) higher than those among IUD users by 1.8, 2.1, 2.3 and 1.9 mm Hg, respectively; the increases in systolic pressure were higher but not significant (p > 0.05) by 1.3, 1.7, 1.5 and 1.3 mm Hg. Neither systolic nor diastolic blood pressure was affected by use of Norplant implants. Regression analysis, including interaction terms, showed that women's age, obesity and family history of hypertension were associated with an increase of blood pressure during follow-up and were independent of contraceptive use and vice versa. After adjustment of some potential confounding variables, pill users showed a 1.0 mm Hg rise in diastolic pressure, which is statistically significant but clinically unimportant.

Three-dimensional structure of baculovirus-expressed Norwalk virus capsids

The three-dimensional structure of the baculovirus-expressed Norwalk virus capsid has been determined to a resolution of 2.2 nm using electron cryomicroscopy and computer image processing techniques. The empty capsid, 38.0 nm in diameter, exhibits T = 3 icosahedral symmetry and is composed of 90 dimers of the capsid protein. The striking features of the capsid structure are arch-like capsomeres, at the local and strict 2-fold axes, formed by dimers of the capsid protein and large hollows at the icosahedral 5- and 3-fold axes. Despite its distinctive architecture, the Norwalk virus capsid has several similarities with the structures of T = 3 single-stranded RNA (ssRNA) viruses. The structure of the protein subunit appears to be modular with three distinct domains: the distal globular domain (P2) that appears bilobed, a central stem domain (P1), and a lower shell domain (S). The distal domains of the 2-fold related subunits interact with each other to form the top of the arch. The lower domains of the adjacent subunits associate tightly to form a continuous shell between the radii of 11.0 and 15.0 nm. No significant mass density is observed below the radius of 11.0 mm. It is suspected that the hinge peptide in the adjoining region between the central domain and the shell domain may facilitate the subunits adapting to various quasi-equivalent environments. Architectural similarities between the Norwalk virus capsid and the other ssRNA viruses have suggested a possible domain organization along the primary sequence of the Norwalk virus capsid protein. It is suggested that the N-terminal 250 residues constitute the lower shell domain (S) with an eight-strand beta-barrel structure and that the C-terminal residues beyond 250 constitute the protruding (P1+P2) domains. A lack of an N-terminal basic region and the ability of the Norwalk virus capsid protein to form empty T = 3 shells suggest that the assembly pathway and the RNA packing mechanisms may be different from those proposed for tomato bushy stunt virus and southern bean mosaic virus but similar to that in tymoviruses and comoviruses.

Norwalk virus infection of volunteers: new insights based on improved assays

Norwalk virus infection is a common cause of gastroenteritis in humans. The clinical features and virologic and immunologic responses following oral administration of Norwalk virus to 50 volunteers were monitored. New ELISAs using recombinant virus particles as the antigen source were used to assess the pattern of virus shedding and the specific immune responses. Forty-one subjects (82%) became infected; 68% were symptomatic and 32% were asymptomatic. The proportion of subjects infected was similar for those with and without preexisting antibody (82% vs. 60%; P > .2). The magnitude of seroconversion was highest in subjects who had vomiting. The peak of viral shedding was between 25 and 72 h, and virus first appeared in stool at 15 h. Specimens collected 7 days after inoculation remained positive. These results show a higher infection rate, more subclinical infections, and longer virus excretion following Norwalk virus inoculation than previously recognized.

[Analysis on refraction status of eyes with normal vision]

Refractive status of 1,324 eyes with normal vision of the juvenile students in four grades was analysed. It was raised that the meaning of refractive status was different between the medical physiological optics and the physical or geometrical optics. "Emmetropia" did not really mean "the normal eye" in refraction as viewed from normal physiology, and the problem about the physiological refractive status of eyes in the juvenile was discussed preliminarily.

Clinical observations on the use of the Chinese herb Tripterygium wilfordii Hook for the treatment of nephrotic syndrome

A preparation of extracts from the root of the Chinese medicinal herb Tripterygium wilfordii Hook was administered orally at a dose of 1 mg/kg body weight per day to 13 children with idiopathic nephrotic syndrome. Eight children, including 4 who were steroid resistant, went into remission which was maintained in 4 for up to 3 years after withdrawal of treatment. In 3 children the proteinuria lessened with the return of plasma protein concentration to normal, and in 1 child this improvement was maintained for 4 years after treatment ceased. No serious side-effects were noted, but a temporary anti-fertility activity has been noted in other studies of both men and women.

Detection of Norwalk virus or Norwalk-like virus infections in Finnish infants and young children

Norwalk virus (NV) and Norwalk-like viruses are important causes of epidemic nonbacterial gastroenteritis in older children and adults. Serologic responses to NV of 154 Finnish infants and young children participating in a rotavirus vaccine study were examined by ELISA with a recently available baculovirus-expressed recombinant NV capsid protein. In 4 serially collected sera (at the median ages of 3, 4, 14, and 23 months), 49% of children had at least one NV infection over the approximately 2-year study period. Children with low NV-specific IgG titers (< 1:50) at the median age of 4 or 14 months were significantly more likely to acquire an NV infection by the median age of 14 or 23 months, respectively, than children who had higher NV IgG titers (> 1:50) (P < .05). Thus, NV or Norwalk-like virus infections are more common in infants and young children than previously believed, and antibody to NV may be protective against such infections.

Epidemiology of early primary hypertension and implications for prevention: the Bogalusa Heart Study

Epidemiological studies of BPs in children and young adults over the past 20 years have contributed considerably to understanding the early onset of primary hypertension. Observations from autopsies and echocardiographic studies, together with long-term BP studies, of children clearly indicate that primary hypertension begins in early childhood. Although abnormal BP levels in children are much lower than the adult criteria used for clinical diagnosis of hypertension, essential hypertension is identifiable in early life. Complex haemodynamic and metabolic mechanisms related to essential hypertension are also being identified in childhood. The development of intervention programs in an attempt to prevent hypertension in its early phases suggests hypertensive cardiovascular disease is preventable. Environmental factors (improved dietary factors, altering electrolyte intake, prevention of obesity and increased activity levels) are critical elements to prevention. Children and young adults identified as high risk for hypertension need to be targeted for prevention of early cardiovascular renal disease. Also, as hypertension is so prevalent, attempts should be made to control environmental factors in the general public. Preventive programmes established by primary healthcare physicians, paediatricians and para-professionals can have a major impact on the reduction of hypertension and its complications of cardiovascular renal disease in the future.

Identification of minireovirus as a Norwalk-like virus in pediatric patients with gastroenteritis

In 1977, 30- to 32-nm virus-like particles, named minireovirus because of their unique morphologic appearance, were detected by electron microscopy in the stools of infants and young children with gastroenteritis. Sequence analysis of approximately 2,800 consecutive bases derived from overlapping PCR clones of a recent minireovirus clinical isolate showed 52% nucleotide sequence identity with the Norwalk virus sequence and, in addition, demonstrated that the genomic organizations of these two viruses were similar. Our data show that minireovirus is a Norwalk-like virus and should now also be included in the Caliciviridae family.