Immune escape and waning immunity of COVID-19 monovalent mRNA vaccines against symptomatic infection with BA.1/BA.2 and BA.5 in Japan

BACKGROUND

Repeated emergence of variants with immune escape capacity and waning immunity from vaccination are major concerns for COVID-19. We examined whether the surge in Omicron subvariant BA.5 cases was due to immune escape or waning immunity through vaccine effectiveness (VE) evaluation.

METHODS

A test-negative case-control study was conducted in 16 clinics/hospitals during the BA.1/BA.2-dominant and BA.5-dominant periods. VE against symptomatic infection was estimated after adjusting for age, sex, comorbidity, occupation, testing frequency, prior infection, close contact history, clinic/hospital, week, and preventive measures. Absolute VE (aVE) was calculated for 2/3/4 doses, compared to the unvaccinated. Relative VE (rVE) was calculated, comparing 3 vs 2 and 4 vs 3 doses.

RESULTS

13,025 individuals were tested during the BA.1/BA.2-dominant and BA.5-dominant periods with similar baseline characteristics. For BA.1/BA.2, aVE was 52 % (95 %CI:34-66) 14 days-3 months post-dose 2, 42 % (29-52) > 6 months post-dose 2, 71 % (64-77) 14 days-3 months post-dose 3, and 68 % (52-79) 3-6 months post-dose 3. rVE was 49 % (38-57) 14 days-3 months post-dose 3 and 45 % (18-63) 3-6 months post-dose 3. For BA.5, aVE was 56 % (27-73) 3-6 months post-dose 2, 32 % (12-47) > 6 months post-dose 2, 70 % (61-78) 14 days-3 months post-dose 3, 59 % (48-68) 3-6 months post-dose 3, 50 % (29-64) > 6 months post-dose 3, and 74 % (61-83) ≥ 14 days post-dose 4. rVE was 56 % (45-65) 14 days-3 months post-dose 3, 39 % (27-48) 3-6 months post-dose 3, 25 % (-2-45) > 6 months post-dose 3, and 30 % (-6-54) ≥ 14 days post-dose 4.

CONCLUSIONS

Booster doses initially provided high protection against BA.5 at a level similar to that against BA.1/BA.2. However, the protection seemed shorter-lasting against BA.5, which likely contributed to the surge. Furthermore, rVE post-dose 4 was low even among recent vaccinees. These results support the introduction of variant-containing vaccines and emphasize the need for vaccines with longer duration of protection.

Effectiveness of BA.1- and BA.4/BA. 5-Containing Bivalent COVID-19 mRNA Vaccines Against Symptomatic SARS-CoV-2 Infection During the BA.5-Dominant Period in Japan

In this multicenter, prospective, test-negative, case-control study in Japan, the effectiveness of both BA.1-containing and BA.4/BA.5-containing bivalent coronavirus disease 2019 mRNA vaccines against symptomatic infection during the BA.5-dominant period was high compared with no vaccination (65% and 76%) and moderate compared with monovalent vaccines administered over half a year earlier (46% combined).

Coronavirus Disease 19 (COVID-19) Vaccine Effectiveness Against Symptomatic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection During Delta-Dominant and Omicron-Dominant Periods in Japan: A Multicenter Prospective Case-control Study (Factors Associated with SARS-CoV-2 Infection and the Effectiveness of COVID-19 Vaccines Study)

BACKGROUND

Although several coronavirus disease 2019 (COVID-19) vaccines initially showed high efficacy, there have been concerns because of waning immunity and the emergence of variants with immune escape capacity.

METHODS

A test-negative design case-control study was conducted in 16 healthcare facilities in Japan during the Delta-dominant period (August-September 2021) and the Omicron-dominant period (January-March 2022). Vaccine effectiveness (VE) against symptomatic severe acute respiratory syndrome coronavirus 2 infection was calculated for 2 doses for the Delta-dominant period and 2 or 3 doses for the Omicron-dominant period compared with unvaccinated individuals.

RESULTS

The analysis included 5795 individuals with 2595 (44.8%) cases. Among vaccinees, 2242 (55.8%) received BNT162b2 and 1624 (40.4%) received messenger RNA (mRNA)-1273 at manufacturer-recommended intervals. During the Delta-dominant period, VE was 88% (95% confidence interval [CI], 82-93) 14 days to 3 months after dose 2 and 87% (95% CI, 38-97) 3 to 6 months after dose 2. During the Omicron-dominant period, VE was 56% (95% CI, 37-70) 14 days to 3 months since dose 2, 52% (95% CI, 40-62) 3 to 6 months after dose 2, 49% (95% CI, 34-61) 6+ months after dose 2, and 74% (95% CI, 62-83) 14+ days after dose 3. Restricting to individuals at high risk of severe COVID-19 and additional adjustment for preventive measures (ie, mask wearing/high-risk behaviors) yielded similar estimates, respectively.

CONCLUSIONS

In Japan, where most are infection-naïve, and strict prevention measures are maintained regardless of vaccination status, 2-dose mRNA vaccines provided high protection against symptomatic infection during the Delta-dominant period and moderate protection during the Omicron-dominant period. Among individuals who received an mRNA booster dose, VE recovered to a high level.

Behavioral factors associated with SARS-CoV-2 infection in Japan

Background

The relative burden of COVID‐19 has been less severe in Japan. One reason for this may be the uniquely strict restrictions imposed upon bars/restaurants. To assess if this approach was appropriately targeting high‐risk individuals, we examined behavioral factors associated with SARS‐CoV‐2 infection in the community.

Methods

This multicenter case–control study involved individuals receiving SARS‐CoV‐2 testing in June–August 2021. Behavioral exposures in the past 2 weeks were collected via questionnaire. SARS‐CoV‐2 PCR‐positive individuals were cases, while PCR‐negative individuals were controls.

Results

The analysis included 778 individuals (266 [34.2%] positives; median age [interquartile range] 33 [27–43] years). Attending three or more social gatherings was associated with SARS‐CoV‐2 infection (adjusted odds ratio [aOR] 2.00 [95% CI 1.31–3.05]). Attending gatherings with alcohol (aOR 2.29 [1.53–3.42]), at bars/restaurants (aOR 1.55 [1.04–2.30]), outdoors/at parks (aOR 2.87 [1.01–8.13]), at night (aOR 2.07 [1.40–3.04]), five or more people (aOR 1.81 [1.00–3.30]), 2 hours or longer (aOR 1.76 [1.14–2.71]), not wearing a mask during gatherings (aOR 4.18 [2.29–7.64]), and cloth mask use (aOR 1.77 [1.11–2.83]) were associated with infection. Going to karaoke (aOR 2.53 [1.25–5.09]) and to a gym (aOR 1.87 [1.11–3.16]) were also associated with infection. Factors not associated with infection included visiting a cafe with others, ordering takeout, using food delivery services, eating out by oneself, and work/school/travel‐related exposures including teleworking.

Conclusions

We identified multiple behavioral factors associated with SARS‐CoV‐2 infection, many of which were in line with the policy/risk communication implemented in Japan. Rapid assessment of risk factors can inform decision making.

Pre-emptive Short-term Nicotinamide Mononucleotide Treatment in a Mouse Model of Diabetic Nephropathy

BACKGROUND

The activation of NAD⁺-dependent deacetylase, Sirt1, by the administration of nicotinamide mononucleotide (NMN) ameliorates various aging-related diseases.

METHODS

Diabetic db/db mice were treated with NMN transiently for 2 weeks and observed for effects on diabetic nephropathy (DN).

RESULTS

At 14 weeks after the treatment period, NMN attenuated the increases in urinary albumin excretion in db/db mice without ameliorating hemoglobin A1c levels. Short-term NMN treatment mitigated mesangium expansion and foot process effacement, while ameliorating decreased Sirt1 expression and increased claudin-1 expression in the kidneys of db/db mice. This treatment also improved the decrease in the expression of H3K9me2 and DNMT1. Short-term NMN treatment also increased kidney concentrations of NAD⁺ and the expression of Sirt1 and nicotinamide phosphoribosyltransferase (Nampt), and it maintained nicotinamide mononucleotide adenyltransferase1 (Nmnat1) expression in the kidneys. In addition, survival rates improved after NMN treatment.

CONCLUSIONS

Short-term NMN treatment in early-stage DN has remote renal protective effects through the upregulation of Sirt1 and activation of the NAD⁺ salvage pathway, both of which indicate NMN legacy effects on DN.

Diabetic condition induces hypertrophy and vacuolization in glomerular parietal epithelial cells

Diabetic nephropathy (DN) is accompanied by characteristic changes in the glomerulus, but little is known about the effect of diabetes on parietal epithelial cells (PECs). In this study, a descriptive analysis of PECs was undertaken in diabetic db/db mice and in diabetic patients. PEC hypertrophy was significantly more prominent in diabetic mice than in nondiabetic mice, and this was evident even at the early stage. Additionally, the number of vacuoles in PECs was markedly increased in diabetic mice, suggesting the presence of cellular injury in PECs in DN. Although rare, binuclear cells were observed in mice with early diabetes. In cultured PECs, a high glucose condition, compared with normal glucose condition, induced cellular hypertrophy and apoptosis. Flow cytometry showed that some PECs in the G0 phase reentered the cell cycle but got arrested in the S phase. Finally, in human diabetic subjects, hypertrophy and vacuolization were observed in the PECs. Our data showed that PECs undergo substantial changes in DN and may participate in rearrangement for differentiation into podocytes.

Role of Nampt-Sirt6 Axis in Renal Proximal Tubules in Extracellular Matrix Deposition in Diabetic Nephropathy

Nicotinamide adenine dinucleotide (NAD⁺) metabolism plays a critical role in kidneys. We previously reported that decreased secretion of a NAD⁺ precursor, nicotinamide mononucleotide (NMN), from proximal tubules (PTs) can trigger diabetic albuminuria. In the present study, we investigated the role of NMN-producing enzyme nicotinamide phosphoribosyltransferase (Nampt) in diabetic nephropathy. The expression of Nampt in PTs was downregulated in streptozotocin (STZ)-treated diabetic mice when they exhibited albuminuria. This albuminuria was ameliorated in PT-specific Nampt-overexpressing transgenic (TG) mice. PT-specific Nampt-conditional knockout (Nampt CKO) mice exhibited TBM thickening and collagen deposition, which were associated with the upregulation of the profibrogenic gene TIMP-1. Nampt CKO mice also exhibited the downregulation of sirtuins, particularly in Sirt6. PT-specific Sirt6-knockout mice exhibited enhanced fibrotic phenotype resembling that of Nampt CKO mice with increased Timp1 expression. In conclusion, the Nampt-Sirt6 axis in PTs serves as a key player in fibrogenic extracellular matrix remodeling in diabetic nephropathy.

Genesis, goals and achievements of Long-Term Ecological Research at the global scale: A critical review of ILTER and future directions

Since its founding in 1993 the International Long-term Ecological Research Network (ILTER) has gone through pronounced development phases. The current network comprises 44 active member LTER networks representing 700 LTER Sites and ~80 LTSER Platforms across all continents, active in the fields of ecosystem, critical zone and socio-ecological research. The critical challenges and most important achievements of the initial phase have now become state-of-the-art in networking for excellent science. At the same time increasing integration, accelerating technology, networking of resources and a strong pull for more socially relevant scientific information have been modifying the mission and goals of ILTER. This article provides a critical review of ILTER's mission, goals, development and impacts. Major characteristics, tools, services, partnerships and selected examples of relative strengths relevant for advancing ILTER are presented. We elaborate on the tradeoffs between the needs of the scientific community and stakeholder expectations. The embedding of ILTER in an increasingly collaborative landscape of global environmental observation and ecological research networks and infrastructures is also reflected by developments of pioneering regional and national LTER networks such as SAEON in South Africa, CERN/CEOBEX in China, TERN in Australia or eLTER RI in Europe. The primary role of ILTER is currently seen as a mechanism to investigate ecosystem structure, function, and services in response to a wide range of environmental forcings using long-term, place-based research. We suggest four main fields of activities and advancements for the next decade through development/delivery of a: (1) Global multi-disciplinary community of researchers and research institutes; (2) Strategic global framework and strong partnerships in ecosystem observation and research; (3) Global Research Infrastructure (GRI); and (4) a scientific knowledge factory for societally relevant information on sustainable use of natural resources.

High Basolateral Glucose Increases Sodium-Glucose Cotransporter 2 and Reduces Sirtuin-1 in Renal Tubules through Glucose Transporter-2 Detection

Under diabetic conditions, sodium-glucose cotransporter 2 (SGLT2) for glucose uptake in proximal tubules (PTs) increases, whereas NAD⁺-dependent protein deacetylase silent mating type information regulation 2 homolog 1 (Sirtuin-1; SIRT1) for PT survival decreases. Therefore, we hypothesized that increased glucose influx by SGLT2 reduces SIRT1 expression. To test this hypothesis, db/db mice with diabetes and high-glucose (HG)-cultured porcine PT LLC-PK1 cells in a two-chamber system were treated with the SGLT2 inhibitor canagliflozin. We also examined SIRT1 and SGLT2 expression in human kidney biopsies. In db/db mice, SGLT2 expression increased with concomitant decreases in SIRT1, but was inhibited by canagliflozin. For determination of the polarity of SGLT2 and SIRT1 expression, LLC-PK1 cells were seeded into Transwell chambers (pore size, 0.4 µm; Becton Dickinson, Oxford, UK). HG medium was added to either or to both of the upper and lower chambers, which corresponded to the apical and basolateral sides of the cells, respectively. In this system, the lower chamber with HG showed increased SGLT2 and decreased SIRT1 expression. Canagliflozin reversed HG-induced SIRT1 downregulation. Gene silencing and inhibitors for glucose transporter 2 (GLUT2) blocked HG-induced SGLT2 expression upregulation. Gene silencing for the hepatic nuclear factor-1α (HNF-1α), whose nuclear translocation was enhanced by HG, blocked HG-induced SGLT2 expression upregulation. Similarly, gene silencing for importin-α1, a chaperone protein bound to GLUT2, blocked HG-induced HNF-1α nuclear translocation and SGLT2 expression upregulation. In human kidney, SIRT1 immunostaining was negatively correlated with SGLT2 immunostaining. Thus, under diabetic conditions, SIRT1 expression in PTs was downregulated by an increase in SGLT2 expression, which was stimulated by basolateral HG through activation of the GLUT2/importin-α1/HNF-1α pathway.

Penile calciphylaxis in a patient on combined peritoneal dialysis and hemodialysis

Calciphylaxis presents with painful purpura and intractable skin ulcers on the trunk and particularly the distal extremities, and it mainly occurs in patients on chronic dialysis. A 66-year-old man with renal failure due to diabetic nephropathy was on peritoneal dialysis alone for 1 year, followed by peritoneal dialysis combined with hemodialysis for 3 years. He developed calciphylaxis of the penis, which was diagnosed from the skin biopsy findings and clinical observation. To treat this condition, PD was stopped and HD was performed three times a week. In addition, warfarin therapy was discontinued and infusion of sodium thiosulfate was performed. The penile ulcers decreased in size and pain was markedly improved, so the patient was discharged from hospital. Following discharge, PD was resumed after changing the peritoneal dialysis fluid to bicarbonate-buffered dialysate. The penile ulcers eventually resolved completely. There have been very few reports about calciphylaxis in patients on combined dialysis modalities. In our patient, penile calciphylaxis progressed when lactate-buffered peritoneal dialysis fluid was used and resolved after switching to bicarbonate-buffered fluid together with cessation of warfarin therapy and infusion of sodium thiosulfate.

Communication from Tubular Epithelial Cells to Podocytes through Sirt1 and Nicotinic Acid Metabolism

We have recently published that tubular epithelial cells affect the podocyte epigenome though nicotinic acid metabolism in diabetic nephropathy (DN), and we have named this relationship "proximal tubule-podocyte communication". In this review, we describe this novel mechanism in the early stage of DN, focusing on the function of renal tubular Sirt1 and Sirt1-related nicotinic acid metabolism. Mainly, we discuss the following three findings. First, we described the details of proximal tubule-podocyte communication. Second, we explained how Sirt1 regulates albuminuria via epigenetic mechanisms. This means that repeated high glucose stress triggers the initial changes in proximal tubules, which lead to the epigenetically irreversible glomerular damages. However, proximal tubular Sirt1 overexpression can rescue these changes. Our previous data indicated that the decrease in Sirt1 expression in proximal tubules caused the reduction in glomerular Sirt1 and the subsequent increase in glomerular Claudin-1. It seemed plausible that some humoral mediator is released from proximal tubules, migrates to podocytes and glomeruli, and affects Sirt1 expression in podocytes. Third, we mentioned a mediator connecting this communication, nicotinamide mononucleotide (NMN). We suggest the potential of Sirt1 or NMN as not only a therapeutic target but also as a prognostic marker of very early stage DN.

Synthesis of highly refractive and highly fluorescent rigid cyanuryl polyimines with polycyclic aromatic hydrocarbon pendants

A series of rigid cyanuryl polyimines, polyguanamines (PGs) bearing polycyclic aromatic hydrocarbon pendants were successfully synthesized from 2-substituted 4,6-dichloro-1,3,5-triazine and aromatic diamine monomers.

The protein Ocular albinism 1 is the orphan GPCR GPR143 and mediates depressor and bradycardic responses to DOPA in the nucleus tractus solitarii

BACKGROUND AND PURPOSE

L-DOPA is generally considered to alleviate the symptoms of Parkinson's disease by its conversion to dopamine. We have proposed that DOPA is itself a neurotransmitter in the CNS. However, specific receptors for DOPA have not been identified. Recently, the gene product of ocular albinism 1 (OA1) was found to exhibit DOPA-binding activity. Here, we have investigated whether OA1 is a functional receptor of DOPA in the nucleus tractus solitarii (NTS).

EXPERIMENTAL APPROACH

We examined immunohistochemical expression of OA1 in the NTS, and the effects of DOPA microinjected into the depressor sites of NTS on blood pressure and heart rate in anaesthetized rats, with or without prior knock-down of OA1 in the NTS, using shRNA against OA1.

KEY RESULTS

Using a specific OA1 antibody, OA1-positive cells and nerve fibres were found in the depressor sites of the NTS. OA1 expression in the NTS was markedly suppressed by microinjection into the NTS of adenovirus vectors carrying the relevant shRNA sequences against OA1. In animals treated with OA1 shRNA, depressor and bradycardic responses to DOPA, but not those to glutamate, microinjected into the NTS were blocked. Bilateral injections into the NTS of DOPA cyclohexyl ester, a competitive antagonist against OA1, suppressed phenylephrine-induced bradycardic responses without affecting blood pressure responses.

CONCLUSION AND IMPLICATIONS

OA1 acted as a functional receptor for DOPA in the NTS, mediating depressor and bradycardic responses. Our results add to the evidence for a central neurotransmitter role for DOPA, without conversion to dopamine.

Plasma orexin-A is lower in patients with narcolepsy

Recently identified hypothalamic peptides called orexins (or hypocretins) have been implicated in the sleep-wake cycle and in sleep disorder narcolepsy. Neuropathological studies have shown that in patients with narcolepsy, global reduction in the expression of orexins occurs due to the loss of orexin neurons in the hypothalamus. Cerebrospinal fluid analysis has confirmed a reduced or undetectable level of orexin-A in most narcolepsy patients. In this study, measurement of plasma orexin showed significantly lower concentrations in patients with narcolepsy than in age- and gender-matched normal controls. These data suggest that low levels of orexin-A in plasma could serve as a biological marker for narcolepsy.

Active intestinal secretion of new quinolone antimicrobials and the partial contribution of P-glycoprotein

Transport of quinolone antimicrobials and the contribution of the secretory transporter P-glycoprotein were studied in-vivo and in-vitro. In rat intestinal tissue (Ussing chambers method) and human Caco-2 cells (Transwell method), grepafloxacin showed secretory-directed transport. In both experimental systems, the secretory-directed transport was decreased by ciclosporin A, an inhibitor of P-glycoprotein, and probenecid, an inhibitor of anion transport systems. This suggested the contribution of P-glycoprotein and anion-sensitive transporter(s). The involvement of P-glycoprotein was investigated by using a P-glycoprotein over-expressing cell line, LLC-GA5-COL150, and P-glycoprotein-gene-deficient mice (mdr1a(-/-)/1b(-/-) mice). LLC-GA5-COL150 cells showed secretory-directed transport of grepafloxacin, while the parent cell line, LLC-PK1, did not. The secretory-directed transport of sparfloxacin and levofloxacin was also detected in LLC-GA5-COL150 cells. In the mdr1a(-/-)/1b(-/-) mice, the intestinal secretory clearance was smaller than that in wild-type mice after intravenous administration of grepafloxacin. Moreover, the absorption from an intestinal loop in mdr1a(-/-)/1b(-/-) mice was larger than that in wild-type mice. Accordingly, it appears that some quinolones are transported by secretory transporters, including P-glycoprotein. The involved transporters function in-vivo not only to transport grepafloxacin from blood to intestine but also to limit its intestinal absorption.

Antimicrobial susceptibilities of Helicobacter pylori isolates under microaerophilic atmospheres established by two different methods

The MICs of clarithromycin, amoxicillin, and metronidazole for 150 Helicobacter pylori isolates were determined using the AnaeroPack system and were compared with those determined using a microaerophilic incubator. The MICs of clarithromycin, amoxicillin, and metronidazole determined under both microaerophilic atmospheres were mostly within one twofold dilution for 146 (97.3%), 150 (100%), and 149 (99.3%) of the isolates, respectively.

Cross-sectional shapes of the internal auditory canal in patients with acoustic neuromas

Cross-sectional images of the internal auditory canal (IAC) were investigated in 23 patients with acoustic neuroma in order to clarify the widening of the IAC. The area of the IAC and the ratio of areas (neuroma side:normal side) were calculated. The shape of the IAC was fitted by an ellipse to obtain the length of the axes and the direction of the long axis. The area of the IAC was 34.2+/-12.2 mm2 in the neuroma side and 18.1+/-4.8 mm2 in the normal side. The neuroma side was larger than the normal side in all patients, and the mean ratio of areas was 1.9. However, the degrees of cochlear and vestibular damage did not correlate with the ratio of areas. The mean ratio of axes of the approximated ellipse was 1.17+/-0.09 in the neuroma side and 1.14+/-0.10 in the normal side; however, no significant difference was seen between the ratio of axes. The directions of the long axes were not always consistent with the positions of the originating nerves of the tumour. Referring to hypothetical models of enlargement of the IAC, our data suggest that the widening of the IAC in the acoustic neuroma was expansive. The data also indicated that symptoms of the acoustic neuroma were caused not only by compression of the nerves but also by other mechanisms, such as vascular insufficiency to the inner ear.

Three-dimensional imaging of the internal auditory canal in patients with acoustic neuroma

Three-dimensional imaging of the internal auditory canal (IAC) was carried out in 21 patients with acoustic neuromas using helical computed tomography. The IAC was widened in 20 patients, but no irregularities of the canal walls were seen. In addition, the shape of the enlarged IAC corresponded to that of the tumor on magnetic resonance imaging. The data suggest that widening of the IAC in acoustic neuroma patients is due to enlargement of the tumor. Other mechanisms, for example, tumor invasion or destruction caused by release of a specific mediator from the tumor, are unlikely to explain these findings; however, further investigation is needed.

Fibrous dysplasia with cystic appearance in maxillary sinus

Fibrous dysplasia (FD) in the paranasal sinuses is uncommon, and its management may be difficult. We report the case of a 25-year-old female with FD exhibiting a cystic appearance in the maxillary sinus. The patient had been complaining of facial swelling for few years. Imagery study showed a cystic lesion and dense bone changes in the maxillary bone. Inferior meatal antrostomy with a nasal endoscope failed to confirm a histological diagnosis. After a 3-year follow-up, the degree of facial swelling was unchanged, and the patient underwent middle meatal antrostomy and was diagnosed with FD.

[Imaging studies and surgical approach to postoperative maxillary cysts]

Surgical treatment for postoperative maxillary cysts (POMC) can be performed using the peroral method, or the endonasal method which is less invasive. Recently, the percentage of cases in which the endonasal method is employed has increased with the widespread use of endoscopy and advancement in imaging techniques. However, the peroral method is still necessary in some cases. During the 5-year period from July 1994 to June 1999, we operated on 29 patients (31 sides) for POMC. The endonasal method was used for 22 sides, and the peroral method was needed for the remaining 9 sides. Following analysis of the CT scans and MR images, we concluded that it is difficult to employ the endonasal method in the following cases; 1) Cysts located in the lateral or anteroinferior portion of the maxillary sinus 2) Small cysts 3) Cysts with a bony wall.

Transport of 1,5-anhydro-D-glucitol into insulinoma cells by a glucose-sensitive transport system

The uptake of 1,5-anhydro-D-glucitol (1,5-AG) occurs by passive mechanisms in cells or tissues that have passive glucose transporters. It is known that serum 1,5-AG concentrations are reduced in patients with diabetes mellitus. To elucidate the metabolism of this substance and its physiological role in pancreatic beta-cells, we assayed 1,5-AG transport in the insulinoma-derived cell lines, RINr and MIN6. Both cell lines showed an insulin-insensitive, concentration-dependent uptake of 1,5-AG with a saturation time of approximately 120 min, and most of the 1,5-AG in the cytoplasm was in the free form. A biphasic saturation curve was obtained using a wide range of 1,5-AG concentrations, suggesting that accumulation was mediated by a high affinity and a low affinity transporter. The high affinity transporter had a K(m) of 10.4 in RINr cells and 13.0 mM in MIN6 cells, and the low affinity transporter had a K(m)100 times, being much higher than the physiological concentrations of 1,5-AG. These results indicate that the 1,5-AG carrier system in insulinoma cells is distinct from that in either the somatic cells or renal tubular cells. These findings also suggest that a unique 1,5-AG transport system is present in pancreatic beta-cells.

The effects of water extracts of CagA positive or negative Helicobacter pylori on proliferation, apoptosis and connexin formation in acetic acid-induced gastric ulcer of rats

AIM

To investigate the influence of water extracts of CagA-positive or -negative Helicobacter pylori on healing of chronic gastric ulcers and on connexin formation, proliferation and apoptosis, in acetic acid-induced chronic gastric ulcers in rats.

METHODS

Acetic acid was used to induce chronic gastric ulcers in rats, and a water extract of H. pylori was given by mouth every day. Connexin 32 formation was assessed using Western blotting as previously described. The frequencies of proliferating cell nuclear antigen staining and of TdT-mediated dUTP-biotin nick end labelling were examined.

RESULTS

In untreated rats, acetic acid-induced gastric ulcers healed after 14 days and the electrophoretic band corresponding to connexin 32 appeared 4 days after ulcer induction. Treatment with a water extract of H. pylori delayed ulcer healing, with the ulcers remaining unhealed even on the 14th day; healing was delayed more when treatment was with an extract of CagA-positive rather than CagA-negative H. pylori. Connexin 32 appeared earlier when treatment was with a CagA-negative rather than a CagA-positive extract, but in both cases later than in the untreated control group. Proliferating cell nuclear antigen labelling on the fourth day was seen in 14.5% +/- 1.6% of mucosal cells of control group, but in 35.9% +/- 1.4% and 36.5% +/- 1.4% of mucosal cells treated with either VacA(+)CagA(-) and VacA(+)CagA(+) H. pylori extract, respectively. Furthermore, extracts of both H. pylori strains, especially VacA(+)Cag(+) H. pylori promoted apoptosis.

CONCLUSIONS

A water extract of H. pylori increased both proliferation and apoptosis, which are related to exacerbation and healing of ulcer as well as appearance of connexin 32.

Rare incidence of interspousal transmission of Helicobacter pylori in asymptomatic individuals in Japan

PCR-restriction fragment length polymorphism electrophoretic patterns of amplified ureB and ureC of Helicobacter pylori were compared between spouses after digestion with restriction endonucleases. Twenty of 21 couples, both members of which were positive for H. pylori, showed ureB and ureC patterns that differed between spouses. We concluded that in Japan, interspousal transmission of H. pylori occurs rarely.

Three-dimensional reconstruction of the incudostapedial joint with helical computed tomography

Three-dimensional images of the incudostapedial joint (I-S joint) were reconstructed using helical computed tomography (CT). The images of the joint were most often reconstructed when threshold values were selected at -500 to -700 Hounsfield Units. These shapes were changed by choosing various threshold values. Histological examinations of the cadaver specimen indicate that these changes are due to structure of the I-S joints. We conclude that these 3-D images may be useful in assessing pathology of the I-S joint.

Epidemiological study on sleep habits and insomnia of new outpatients visiting general hospitals in Japan

A large scale epidemiological survey of sleep habits, specifically for insomnia, was conducted using 6277 new outpatients from 11 general hospitals in Japan. They were requested to answer a questionnaire newly designed for this study, which consisted of 34 questions concerning sociodemographic characteristics, current medical conditions, sleep habits, current or past sleep complaints, symptoms of parasomnia, use of hypnotics/anxiolytics and other aspects of daily life. Insomnia was the focus of analysis using chi2 statistics and, additionally, logistic regression to explore the predictors of insomnia. Bedtime was 23:30 and wake-up time was 6:35 on average, with a mean sleep time of 6.77 h on weekdays. The number of subjects with current sleep complaints was 1276, of which 735 (11.7% of the total sample) had insomnia lasting for 1 month or more. Only 37.6% of those were taking hypnotics and/or anxiolytics. Old age, female sex, neurology, psychiatry, early bedtime, late wake-up time, living alone and dissatisfaction with the bedroom environment for sleep were found to be associated with long-term insomnia. This study helps to provide a framework for further studies using the general population.

Glutathione reductase activity and flavin concentration in guinea-pig tissues

Glutathione reductase (GR) activity and flavin concentration were studied in systemic tissues (brain, heart, lung, liver, spleen, stomach, pancreas, muscle, kidney, testis) and blood components (erythrocytes and plasma) from male guinea-pigs. GR activity and the flavin concentration were high in kidney and liver, and low in muscle. GR activity in erythrocytes was found in a range of tissues, but flavin concentration in erythrocytes was lower than in any tissues. GR was saturated with flavin adenine dinucleotide (FAD) in almost all tissues, but not in muscle or erythrocytes.

[Effect of antibiotics and antibody on phagocytic bactericidal activity of polymorphonuclear neutrophils of Bordetella pertussis]

The phagocytic bactericidal activity of the polymononucler neutrophils (PMNs) that were collected from healthy volunteer with and without antibody against Bordetella pertussis was investigated. Furthermore, these activity against B. pertussis under observing penicillins or macrolides antibiotics was investigated. Although no efficacy to B. pertussis strain by the PMNs in serum without antibody, but the viable cells of B. pertussis decreased to 1/1,000 1 hr after incubation and was not detected after 4 hrs. In particular, the viable cells of B. pertussis by the PMNs in serum with antibody was markedly reduced when azithromycin was present. These results suggests that the synergistic action of macrolide antibiotics and antibody-mediated phagocytic bactericidal activity on B. pertussis may have clinical relevance.

Two cases of adult varicella accompanied by hepatic dysfunction

Varicella is a typical acute exanthematous viral infection caused by varicella-zoster virus (VZV). In recently years, as far as hepatic dysfunction caused by viruses other than the hepatitis virus is concerned, there have been a few reports on hepatic dysfunction accompanying varicella following organ transplantation of Europe and America and another report on an immunocompromized adult following treatment for Systemic lupus erythematosis (SLE) in Japan. Nonetheless, we searched the MEDLINE and J MEDICINE listing the publications between 1986 and 1996 and found one report on healthy adults with varicella accompanied by hepatic dysfunction in Europe and America and two reports in Japan. Only Noguchi et al. dealt with the findings of liver biopsy. We examined two healthy adults with varicella and mild-to-moderate hepatic dysfunction, and referred to the results of their liver biopsies. The present paper discusses this issue, citing some references.