The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7-3946

Protons with energies up to approximately 10(15) eV are the main component of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants, and the shock waves associated with such remnants, when they hit the surrounding interstellar medium, could also provide the energy to accelerate protons. The signature of such a process would be the decay of pions (pi(0)), which are generated when the protons collide with atoms and molecules in an interstellar cloud: pion decay results in gamma-rays with a particular spectral-energy distribution. Here we report the observation of cascade showers of optical photons resulting from gamma-rays at energies of approximately 10(12) eV hitting Earth's upper atmosphere, in the direction of the supernova remnant RX J1713.7-3946. The spectrum is a good match to that predicted by pion decay, and cannot be explained by other mechanisms.

Production of male cloned mice from fresh, cultured, and cryopreserved immature Sertoli cells

Although it is generally accepted that relatively high efficiencies of somatic cell cloning in mammals can be achieved by using donor cells from the female reproductive system (e.g., cumulus/granulosa, oviduct, and mammary gland cells), there is little information on the possibility of using male-specific somatic cells as donor cells. In this study we injected the nucleus of immature mouse Sertoli cells isolated from the testes of newborn (Days 3-10) males into enucleated mature oocytes in order to examine the ability of their nuclei to support embryonic development. After activation of the oocytes that had received the freshly recovered immature Sertoli cells, some developed into the morula/blastocyst stage, depending on the age of the donor cells (22.0-37.4%). When transferred into pseudopregnant females, 7 (3.3%, 7 of 215) developed into normal pups at term. Nuclear transfer of immature Sertoli cells after 1 wk in culture also produced normal pups after embryo transfer (3.1%, 2 of 65). Even after cryopreservation in a conventional cryoprotectant solution, their ability as donor cells was maintained, as demonstrated by the birth of cloned young (6.7%, 7 of 105). Immature Sertoli cells transfected with green fluorescent protein gene also supported embryo development into morulae/blastocysts, which showed specific fluorescence. This study demonstrates that immature Sertoli cells, male-specific somatic cells, are potential donors for somatic cell cloning.

The role of spreading depression in focal ischemia evaluated by diffusion mapping

This study investigated the role of spontaneous and induced spreading depression (SD) on the evolution of focal ischemia in vivo. We induced focal ischemia in 12 rats using the middle cerebral artery suture occlusion (MCAO) method. Chemical stimulation of nonischemic ipsilateral cortex by potassium chloride application (KCl group; n = 7) and saline (NaCl group; n = 5) was performed at 15, 30, 45, and 60 minutes following MCAO, and SD was detected electrophysiologically. Ischemic lesion volumes assessed over 15-minute intervals, evaluated by continuous apparent diffusion coefficient (ADC) of water mapping, demonstrated that the ischemic region increased significantly during 15-minute time epochs with a single SD episode (36.5 +/- 12.9 mm3, mean +/- SD) or multiple SD episodes (39.8 +/- 22.3) compared with those without SD (13.9 +/- 11.5) (p = 0.0009). Infarct volume at postmortem 24 hours after MCAO was significantly larger in the KCl group, with more total SDs (237.8 +/- 13.8) than the NaCl group (190.5 +/- 12.6) (p = 0.0001). This study demonstrates that ischemia-related and induced SDs increase significantly ischemic lesion volume in vivo, supporting the hypothesis for a causative role of SD in extending focal ischemic injury.

Small chronic hemorrhages and ischemic lesions in association with spontaneous intracerebral hematomas

BACKGROUND AND PURPOSE

It has been speculated that the same type of hypertensive small-artery disease can cause either intracerebral hemorrhages or ischemic lesions, depending on the circumstances.

METHODS

To test this hypothesis, we examined the association between spontaneous intracerebral hematomas and both small chronic hemorrhages and ischemic lesions using echo planar and T2-weighted MRI. We considered a hypointense area to represent a hemorrhage and a hyperintense area to represent an ischemic lesion.

RESULTS

We identified small hypointense lesions in 56.7% of 30 patients with intracerebral hematomas (mean age, 62.2 years; total number of lesions, 108) and in 25.4% of 59 patients without hematomas (mean age, 67.6 years; total lesions, 28). The incidence of hypertension was 88.3% in patients with intracerebral hematomas and 42.3% in those without. The hypointense lesions were found in 56.0% of 50 patients with hypertension, whereas they were found only in 10.3% of 39 patients without hypertension. The hypointense lesions were most common in the subcortex, followed by the putamen, pons, thalamus, and cerebellum. The hyperintense lesions were of a higher grade in patients with intracerebral hematomas than in those without. The hypointense lesions were commonly surrounded by hyperintense areas. Additionally, in 3 of 3 autopsied brains, we found hemosiderin deposits around arteriosclerotic microvessels and a surrounding small infarction in areas that had appeared as small hypointense lesions surrounded by hyperintensity on MRI. One specimen also had an organized miliary pseudoaneurysm.

CONCLUSIONS

Our findings indicate that spontaneous intracerebral hematomas are frequently associated with small chronic hemorrhages, ischemic lesions, and hypertension. We speculate that hypertensive intracerebral hemorrhage may have the same microangiopathic basis as cerebral infarction.

Amyloid protofilament formation of hen egg lysozyme in highly concentrated ethanol solution

Mutant human lysozymes (Ile56Thr & Asp67His) have been reported to form amyloid deposits in the viscera. From the standpoint of understanding the mechanism of amyloid formation, we searched for conditions of amyloid formation in vitro using hen egg lysozyme, which has been extensively studied from a physicochemical standpoint. It was found that the circular dichroism spectra in the far-ultraviolet region of the hen egg lysozyme changed to those characteristic of a beta-structure from the native alpha-helix rich spectrum in 90% ethanol solution. When the concentration of protein was increased to 10 mg/mL, the protein solution formed a gel in the presence of 90% ethanol, and precipitated on further addition of 10 mM NaCl. The precipitates were examined by electron microscopy, their ability to bind Congo red, and X-ray diffraction to determine whether amyloid fibrils were formed in the precipitates. Electron micrographs displayed unbranched protofilament with a diameter of approximately 70 A. The peak point of the difference spectrum for the Congo red binding assay was 541 nm, which is characteristic of amyloid fibrils. The X-ray diffraction pattern showed a sharp and intense diffraction ring at 4.7 A, a reflection that arises from the interstrand spacing in beta-sheets. These results indicate that the precipitates of hen egg lysozyme are amyloid protofilament, and that the amyloid protofilament formation of hen egg lysozyme closely follows upon the destruction of the helical and tertiary structures.

Specific inhibition of adherence of an oral strain of Bacteroides gingivalis 381 to epithelial cells by monoclonal antibodies against the bacterial fimbriae

Monoclonal antibodies against purified fimbriae from this organism blocked its adherence to buccal epithelial cells. Three clones of monoclonal antibodies against these fimbriae were selected for use. The isotype of the three was IgG1 kappa chain. The antibodies reacted with fimbriae or their partially dissociated oligomers, but not with their constituent monomers (43 K protein, fimbrilin) or with other B. gingivalis 381 components, in an enzyme-linked immunosorbent assay or by immuno-blotting. The antibodies agglutinated only B. gingivalis 381 cells and no other species of Bacteroides. The purified immunoglobulin G (IgG) antibodies inhibited bacterial adherence to the human buccal epithelial cells, but had no effect on bacterial haemagglutination to various animal and human erythrocytes. The papain-cleaved Fab fragment, which did not allow cell to cell cross-linking, also inhibited adherence of B. gingivalis 381 but did not interfere with haemagglutination. Thus the fimbriae of B. gingivalis 381 may be responsible for adherence to epithelial cells, which supports the notion that a different type of fimbria or a lectin-like protein may be acting as haemagglutinin in this bacterium.

Two novel nodal-related genes initiate early inductive events in Xenopus Nieuwkoop center

In vertebrates, Nodal-related protein plays crucial roles in mesoderm and endoderm induction. Here we describe two novel Xenopus nodal-related genes, Xnr5 and Xnr6, which are first zygotically expressed at the mid-blastula transition, in the dorsal-vegetal region including the Nieuwkoop center. Xnr5 and Xnr6 were isolated by expression screening of a library enriched with immediate-early-type transcripts, and are strong inducers of both mesoderm and endoderm. They also induce the other nodal-related genes in the animal cap. In embryos, cerberus-short (nodal-specific inhibitor) can inhibit Xnr1 and Xnr2 express to the same extent goosecoid, but not Xnr5 and Xnr6 transcription. Xnr5 and Xnr6 are regulated completely cell autonomously, differently from other Xnrs in the cell-dissociated embryos. The expression of Xnr5 and Xnr6 is regulated by maternal VegT and (beta)-catenin, but does not require TGF-(beta) signaling. Therefore, expression of Xnr5 and Xnr6 is controlled by different mechanisms from other Xnr family genes.

Dysregulated expression of P1 and P2 promoter-driven hepatocyte nuclear factor-4α in the pathogenesis of human cancer

Hepatocyte nuclear factor-4alpha (HNF4alpha) exists in multiple isoforms that are generated by alternative promoter (P1 and P2) usage and splicing. Here we establish monoclonal antibodies (mAbs) for detecting P1 and P2 promoter-driven HNF4alpha, and evaluate their expression in normal adult human tissues and surgically resected carcinomas of different origins. Using immunohistochemical analysis, we demonstrate that, while P1 promoter-driven HNF4alpha is expressed in hepatocytes, small intestine, colon, kidney and epididymis, P2 promoter-driven HNF4alpha is expressed in bile duct, pancreas, stomach, small intestine, colon and epididymis. Altered expression patterns of P1 and P2 promoter-driven HNF4alpha were observed in gastric, hepatocellular and colorectal carcinomas. HNF4alpha was expressed in lung metastases from renal cell, hepatocellular and colorectal carcinoma but was not observed in lung tumours. The P1 and P2 promoter-driven HNF4alpha expression pattern of tumour metastases correlated with the primary site of origin. P1 promoter-driven HNF4alpha was also found in intestinal metaplasia of the stomach. These data provide evidence for the tissue distribution of P1 and P2 promoter-driven HNF4alpha at the protein level and suggest that HNF4alpha may be a novel diagnostic marker for metastases of unknown primary. We propose that the dysregulation of alternative promoter usage of HNF4alpha is associated with the pathogenesis of certain cancers.

Transcatheter arterial embolization of ruptured pseudoaneurysms with coils and n-butyl cyanoacrylate

PURPOSE

To evaluate the clinical efficacy of transcatheter arterial embolization with n-butyl cyanoacrylate (NBCA) for ruptured pseudoaneurysms, which are difficult to control by coil embolization alone.

MATERIALS AND METHODS

Ruptured pseudoaneurysms developed at the celiac trunk (n = 1), gastroduodenal artery (n = 2), pancreatic arcade (n = 1), hepatic artery (n = 3), renal artery (n = 1), and intercostal artery (n = 1) in nine patients. NBCA was mixed with iodized-oil (1:2) and injected via the 3-F microcatheter under fluoroscopic guidance, after the catheter was advanced close to the pseudoaneurysm. Coil embolization was performed to control blood flow before administration of NBCA in seven patients. NBCA was injected immediately after coil embolization in four patients. Embolization with NBCA was performed for recurrent bleeding that occurred within 1-21 days (mean, 10.7 days) after initial coil embolization in three patients. Two patients with peripheral pseudoaneurysms underwent embolization with NBCA alone.

RESULTS

The NBCA mixture was visible under fluoroscopy, and was useful in monitoring the embolization process and deciding the endpoint. Embolization was technically successful without major complications in all patients. Pseudoaneurysms and afferent and efferent arteries were eliminated immediately after embolization. Bleeding was stopped after embolization in all cases. Rebleeding did not occur in any patient during their follow-up periods of 0.7-69.5 months (mean, 17.9 months).

CONCLUSION

Embolization with NBCA is a feasible and useful treatment for ruptured pseudoaneurysms, which are difficult to control by coil embolization alone.

A novel endothelin antagonist, A-127722, attenuates ischemic lesion size in rats with temporary middle cerebral artery occlusion: a diffusion and perfusion MRI study

BACKGROUND AND PURPOSE

Endothelins (ETs) are potent vasoconstrictors. Plasma ET levels increase during acute brain ischemia and may worsen the ischemic damage. Diffusion-weighted MRI (DWI) and perfusion imaging (PI) are powerful tools for evaluation of acute cerebral ischemia. We studied the effects of A-127722, a novel ET(A)-selective ET antagonist, on cerebral ischemic lesion size using 2,3,5-triphenyltetrazolium chloride (TTC) staining postmortem, on acute ischemic lesion development with DWI, and on the cerebral circulation using PI.

METHODS

Twenty male Sprague-Dawley rats received either 5 mg/kg of A-127722 or vehicle (n=10 per group) intravenously 30 minutes and subcutaneously 4 hours after middle cerebral artery occlusion (MCAO). Whole-brain DWI and single-slice PI were done before initiation of treatment and repeated frequently thereafter up to 4 hours after MCAO. The animals were reperfused in the MRI scanner 90 minutes after the onset of MCAO. At 24 hours the animals were killed, and the brains were cut into six 2-mm-thick slices and stained with 2% TTC. Percent hemispheric lesion volume (%HLV) was calculated for each animal.

RESULTS

Physiological parameters, body weight, neurological scores, and premature mortality (2 versus 2) did not differ between the two groups. No hypotension, abnormal behavior, or other adverse effects were seen. TTC-derived %HLV was 25.3+/-5.6% for controls and 16.2+/-9.6% for treated animals (36% reduction, P<.02). Six animals in each group had successful reperfusion as shown by PI. Among these animals, %HLV was 23.2+/-3.1% for controls and 9.3+/-4.4% for treated animals (60% reduction, P=.0001). The beneficial effect of A-127722 was limited to animals in which successful reperfusion was demonstrated. No difference in PI-detected perfusion deficit size was observed between the groups. DWI did not demonstrate significant in vivo lesion size differences.

CONCLUSIONS

A-127722 significantly reduced ischemic lesion size in rats without observable adverse effects. It is not clear whether the effect was due to vasodilatation of collateral arterioles not detectable by PI or whether A-127722 has neuroprotective properties that are independent of vascular effects.

Glomerulonephritis associated with MRSA infection: a possible role of bacterial superantigen

We report 10 cases of glomerulonephritis following methicillin-resistant Staphylococcus aureus (MRSA) infection. The clinical features of this syndrome were an abrupt or insidious onset of rapidly progressive glomerulonephritis (RPGN) with nephrotic syndrome and occasionally purpura, following MRSA infection. The renal histologic findings showed a variety of types of proliferative glomerulonephritis with varying degrees of crescent formation; immunofluorescence revealed of glomerular deposition of IgA, IgG, and C3. Laboratory findings showed polyclonal increases of serum IgA and IgG, with high levels of circulating immune complexes (ICs). Increased numbers of DR+CD4+, and DR+CD8+T cells were observed in the peripheral circulation, with a high frequency of T cell receptor (TCR) V beta + cells. MRSA produced enterotoxins C and A and toxic shock syndrome toxin (TSST)-1, all of which are known to act as superantigens. From the above observations, we speculate that post-MRSA glomerulonephritis may be induced by superantigens causing production of high levels of cytokines, and polyclonal activation of IgG and IgA. The formation of ICs containing IgA and IgG in the circulation result in development of glomerulonephritis and vasculitis. Accordingly, microbial superantigens may play an important role in the pathogenesis of this unique syndrome of nephritis and vasculitis.

The structure and function of folliculo-stellate cells in the anterior pituitary gland

The folliculo-stellate cells (FS cells) in the anterior pituitary gland are characterized by their star-like appearance and their ability to form follicles. Although FS cells do not produce any pituitary hormones, their special tendency to surrounding endocrine cells with their long cytoplasmic processes suggests that they regulate endocrine cells by intercellular communication. In spite of many morphological and cytophysiological studies recently performed, a precise understanding of the major functions of FS cells in the pituitary gland remains obscure. We review here the morphological characteristics of FS cells and their suspected functions in the anterior pituitary gland. It is well established that the FS cell produces many kinds of growth factors, i.e., fibroblast growth factor, vascular endothelial cell growth factor and interleukin 6. The biological significances of these growth factors in the anterior pituitary gland are also discussed in this paper. The origin and differentiation of FS cells, especially the possibility that the FS cell is a kind of stem cell which has the potential to differentiate into endocrine cells, is also presented.

Impaired respiratory mechanics in pulmonary emphysema: evaluation with dynamic breathing MRI

To evaluate impaired respiratory mechanics in pulmonary emphysema, dynamic breathing magnetic resonance imaging (BMRI) was acquired with fast-gradient echo pulse sequences at fixed thoracic planes over two to three slow, deep respiratory cycles in 6 controls and 28 patients with pulmonary emphysema including 9 patients undergoing lung volume reduction surgery (LVRS). Respiratory motions of the diaphragm and chest wall (D/CW) were assessed by a cine-loop view, a fusion display of maximal inspiratory and expiratory images, and the time-distance curves. By contrast with normal subjects with regular synchronous D/CW motions, the patients frequently showed reduced, irregular, or asynchronous motions, with significant decreases in the maximal amplitude of D/CW motions (MAD and MACW), and the length of apposition of the diaphragm (LAD) (P < 0.0001, P < 0.001, P < 0. 01, respectively). After LVRS, nine patients showed improvements in D/CW configuration and mobility, with significantly increased MAD, MACW, and LAD (P < 0.01, P < 0.0001, and P < 0.05, respectively). In 40 studies of 28 patients including the post-LVRS examinations, the normalized MAD and MACW significantly correlated with %FEV(1) (r = 0. 881 and r = 0.906; P < 0.0001, respectively). BMRI seems useful for noninvasively and directly assessing the impaired respiratory mechanics associated with abnormal ventilation in pulmonary emphysema, and also for monitoring the effects of LVRS. J. Magn. Reson. Imaging 1999;10:510-520.

Birth of mice after nuclear transfer by electrofusion using tail tip cells

Mice have been successfully cloned from cumulus cells, fibroblast cells, embryonic stem cells, and immature Sertoli cells only after direct injection of their nuclei into enucleated oocytes. This technical feature of mouse nuclear transfer differentiates it from that used in domestic species, where electrofusion is routinely used for nuclear transfer. To examine whether nuclear transfer by electrofusion can be applied to somatic cell cloning in the mouse, we electrofused tail tip fibroblast cells with enucleated oocytes, and then assessed the subsequent in vitro and in vivo development of the reconstructed embryos. The rate of successful nuclear transfer (fusion and nuclear formation) was 68.8% (753/1094) and the rate of development into morulae/blastocysts was 40.8% (260/637). After embryo transfer, seven (six males and one female; 2.5% per transfer) normal fetuses were obtained at 17.5-21.5 dpc. These rates of development in vitro and in vivo are not significantly different from those after cloning by injection (44.7% to morulae/blastocysts and 4.8% to term). These results indicate that nuclear transfer by electrofusion is practical for mouse somatic cell cloning and provide an alternative method when injection of donor nuclei into recipient oocytes is technically difficult.

Contribution of hydrophobic residues to the stability of human lysozyme: calorimetric studies and X-ray structural analysis of the five isoleucine to valine mutants

In order to understand the contribution of hydrophobic residues to the conformational stability of human lysozyme, five Ile mutants (Ile --> Val) in the interior of the protein were constructed. The thermodynamic parameters characterizing the denaturation of these mutant proteins were determined by scanning calorimetry, and the three-dimensional structure of each mutant protein was solved at high resolution by X-ray crystallography. The thermodynamic analyses at 64.9 degrees C and at pH 2.7 revealed the following. (1) The stabilities of all the mutant proteins were decreased as compared with that of the wild-type protein. (2) The changes in the calorimetric enthalpies were larger than those in the Gibbs energies, and were compensated by entropy changes. (3) The destabilization mechanism of the mutant proteins differs, depending on the location of the mutation sites. X-ray analyses showed that the overall structures of all the mutant human lysozymes examined were identical to that of the wild-type protein, and only small structural rearrangements were observed locally around some of the mutation sites. The most striking change among the mutant proteins was found in the mutant protein, 159V, which contains a new water molecule in the cavity created by the mutation. The thermodynamic stabilities of the mutant proteins are discussed in light of the high-resolution X-ray structures of the wild-type and five mutant human lysozymes examined.

Superselective bronchial artery embolization for hemoptysis with a coaxial microcatheter system

PURPOSE

To compare the effectiveness and safety of superselective bronchial artery embolization with that of nonsuperselective embolization in the control of hemoptysis.

MATERIALS AND METHODS

Retrospective case analysis was done for 47 patients with hemoptysis originating from a variety of causes. In 22 patients, embolization was performed superselectively using a microcatheter inserted into the bronchial artery beyond the spinal or mediastinal branches (superselective group). In the remaining 25 patients, embolization was performed at the opening of the bronchial artery with a 5-F catheter (nonsuperselective group).

RESULTS

Initial hemoptysis control rates were 96% (21 of 22) in the superselective group and 88% (22 of 25) in the nonsuperselective group. Cumulative hemoptysis control rates of the superselective and nonsuperselective groups were 80% and 67% at 6 months, 79% and 56% at 1 and 2 years, and 79% and 48% at 3 years, respectively (not significant; generalized Wilcoxon test). One major complication (spinal infarction) occurred in the nonsuperselective group.

CONCLUSIONS

Superselective embolization is safer and more effective way to control hemoptysis than the ordinary (nonsuperselective) method.

Amyloid fibrils from the viewpoint of protein folding

In amyloid related diseases, proteins form fibrillar aggregates with highly ordered beta-sheet structure regardless of their native conformations. Formation of such amyloid fibrils can be reproducible in vitro using isolated proteins/peptides, suggesting that amyloid fibril formation takes place as a result of protein conformational change. In vitro studies revealed that perturbation of the native structure is important for the fibril formation, and it is suggested that the mechanisms of amyloid fibril formation share the mechanisms of protein folding. In particular, amyloid fibril formation is similar to one of the common features of proteins, i.e. amorphous aggregation upon partial unfolding, which is likely driven by hydrophobic interactions through exposed protein interior. However, these molecular associations are distinct phenomena, and identifying factors that lead to amyloid fibril formation would precede our understanding of the mechanisms of amyloid fibrillization. The necessity of understanding the nature of protein denatured states is also suggested.

The role of IL-33 and its receptor ST2 in human nasal epithelium with allergic rhinitis

BACKGROUND

Interleukin (IL)-33 is a novel member of the IL-1 cytokine family and a ligand for the orphan IL-1 family receptor ST2. The IL-33 induces T helper 2-type inflammatory responses and is considered to play a crucial rule in allergic inflammations, such as asthma and atopic dermatitis. However, the role of IL-33 and its receptor ST2 in allergic rhinitis remains unknown.

OBJECTIVE

We investigated expression of IL-33 and ST2 in the nasal epithelium of patients with allergic rhinitis and the mechanisms of the production of cytokines/chemokines induced by treatment with IL-33 using normal human nasal epithelial cells (HNECs) in vitro.

METHODS

Expression of IL-33 and ST2 in normal and allergic rhinitis nasal mucosa was evaluated by reverse transcription- and real-time polymerase chain reactions and immunohistochemical methods. The IL-33 in serum, and IL-8 and GM-CSF were measured by ELISA. For in vitro experiments, HNECs in primary culture were used.

RESULTS

The IL-33 levels in the sera of patients with allergic rhinitis were significantly higher than that in normal controls. Expression of IL-33 and ST2 was significantly elevated in the epithelium from patients with allergic rhinitis. The IL-33 mRNA in HNECs in vitro was significantly induced by treatment with IFN-γ and the toll-like receptor 9 ligand ODN2006. The IL-33-induced production of IL-8 and GM-CSF from HNECs in vitro was significantly suppressed by corticosteroid treatment and distinct signal transduction inhibitors of ERK, p38 MAPK, JNK, NF-κB and epidermal growth factor receptor.

CONCLUSIONS AND CLINICAL RELEVANCE

The IL-33 and its receptor ST2 play important roles in allergic rhinitis. The IL-33-mediated inflammatory responses via ST2 are regulated by distinct signalling pathways in HNECs and the IL-33/ST2 pathway may provide new therapeutic targets for allergic rhinitis.

Green tea ingestion greatly reduces plasma concentrations of nadolol in healthy subjects

This study aimed to evaluate the effects of green tea on the pharmacokinetics and pharmacodynamics of the β-blocker nadolol. Ten healthy volunteers received a single oral dose of 30 mg nadolol with green tea or water after repeated consumption of green tea (700 ml/day) or water for 14 days. Catechin concentrations in green tea and plasma were determined. Green tea markedly decreased the maximum plasma concentration (C(max)) and area under the plasma concentration-time curve (AUC(0-48)) of nadolol by 85.3% and 85.0%, respectively (P < 0.01), without altering renal clearance of nadolol. The effects of nadolol on systolic blood pressure were significantly reduced by green tea. [(3)H]-Nadolol uptake assays in human embryonic kidney 293 cells stably expressing the organic anion-transporting polypeptides OATP1A2 and OATP2B1 revealed that nadolol is a substrate of OATP1A2 (Michaelis constant (K(m)) = 84.3 μmol/l) but not of OATP2B1. Moreover, green tea significantly inhibited OATP1A2-mediated nadolol uptake (half-maximal inhibitory concentration, IC(50) = 1.36%). These results suggest that green tea reduces plasma concentrations of nadolol possibly in part by inhibition of OATP1A2-mediated uptake of nadolol in the intestine.

Peptic ulcer is prevalent among shift workers

To elucidate sleep disturbances in the etiology of peptic ulcers, the prevalence of peptic ulcer disease was compared among shift workers and daytime workers. The subjects (N = 11,657) were employees of various institutions, such as factories, banks, or schools, and had undergone a mass x-ray examination of the upper gastrointestinal tract. With present shift workers (N = 2269), the prevalence of gastric ulcers was 2.38% (N = 54) and that of duodenal ulcers, 1.37% (N = 31). With the past shift workers (N = 2111), the prevalence of gastric ulcers was 1.52% (N = 32) and that of duodenal ulcers, 0.62% (N = 13). On the contrary, with the daytime workers (N = 6525) the prevalence of gastric ulcer was 1.03% (N = 67) and that of duodenal ulcer, 0.69% (N = 45). The working schedule for 752 examinees was unknown. The prevalence of gastric and duodenal ulcers was higher with shift workers than daytime workers. Thus, shift work involving sleep disturbances may play an important role in the development of peptic ulcers.

Contribution of water molecules in the interior of a protein to the conformational stability

Water molecules frequently occur in the interior of globular proteins. To elucidate the contribution of buried water molecules to the conformational stability of a protein, we examined the crystal structures and the thermodynamic parameters of denaturation of six Ile to Ala/Gly mutant human lysozymes, in which a cavity is created at each mutation site by the substitution of a smaller side-chain for a larger one. One or two ordered water molecules were found in the cavities created in some mutants (I106A, I59A and I59G). The cavity volumes for these three mutants were bigger than those that remained empty in the other mutants. The stability of the mutant proteins with the newly introduced water molecules was about 8 kJ/mol higher than that expected from the change in hydrophobic surface area (DeltaDeltaASAHP) exposed upon denaturation. It was concluded that a water molecule in a cavity created in the interior of a protein contributes favorably to the stability.