Impact of control measures including decolonization and hand hygiene for orthopaedic surgical site infection caused by MRSA at a Japanese tertiary-care hospital.

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) is the most common pathogen in orthopaedic surgical site infections (SSIs). However, few studies have investigated the transmission process of orthopaedic MRSA SSI. AIM: To investigate the transmission process of orthopaedic MRSA SSI using epidemiological and molecular analyses and to determine a method to prevent MRSA SSI in nosocomial orthopaedic surgery. METHODS: Active MRSA surveillance, preoperative decolonization and contact precautions for MRSA-positive cases was performed at our institution. Changes in epidemic strains were evaluated and the possibility of transmission from patients in an orthopaedic ward of a Japanese tertiary-care hospital was assessed by genotyping stored MRSA strains. In addition, data on the prevalence of MRSA SSI, MRSA colonization, and use of an alcohol antiseptic agent (mL/patient-days) during 2005-2022 were retrospectively assessed. FINDINGS: SCCmec type II strain in the SSI group decreased over time, associated with fewer outbreaks. Even during a period of high infection rates, no cases of transmission-induced SSI from nasal MRSA carriers were identified. The infection rate correlated negatively with the use of an alcohol antiseptic agent (r = -0.82; P < 0.0001). Two cases among five nasal carriers developed MRSA SSI caused by strains different from those related to nasal colonization. CONCLUSION: The infection control measures for transmission from the hospital reservoirs including strict adherence to hand hygiene and decolonization of carriers is likely to be important for the prevention of orthopaedic MRSA SSI. However, the need for contact precautions for decolonized nasal carriers might be low.

Prognostic impact of LAT1 and CD98 expression in cutaneous angiosarcoma.

L-type amino acid transporter 1 (LAT1) and CD98 are frequently expressed in various human cancers, and closely correlated with tumor aggressiveness and survival. However, little is known about the expression of LAT1 and CD98 in cutaneous angiosarcoma. The aim of this study is to investigate the clinicopathological significance of these markers in the dismal disease. A total of 52 patients with cutaneous angiosarcoma were retrospectively reviewed. Immunohistochemical staining of tumor specimens were evaluated using anti-LAT1, CD98 and Ki-67 antibodies. The rates of high expression for LAT1 and CD98 were 56% (29/52) and 79% (41/52), respectively. The frequency of high expression for CD98 was significantly higher than that for LAT1 (p=0.021). The low expression of CD98 was significantly associated with distant metastasis (p=0.044) and was identified as a significant prognostic predictor by multivariate analysis. The expression level of LAT1 was not significantly correlated with prognosis. The low expression of CD98 is a novel biomarker for predicting poor prognosis in patients with cutaneous angiosarcoma.

Prognostic significance of amino-acid transporter expression (LAT1, ASCT2, and xCT) in surgically resected tongue cancer.

BACKGROUND: Amino-acid transporters are necessary for the tumour cell growth and survival, and have a crucial role in the development and invasiveness of cancer cells. But, it remains unclear about the prognostic significance of L-type amino-acid transporter 1 (LAT1), system ASC amino-acid transporter-2 (ASCT2), and xCT expression in patients with tongue cancer. We conducted the clinicopathological study to investigate the protein expression of these amino-acid transporters in tongue cancer. METHODS: Eighty-five patients with surgically resected tongue cancer were evaluated. Tumour sections were stained by immunohistochemistry for LAT1, ASCT2, xCT, 4F2hc/CD98hc (4F2hc), Ki-67, and microvessel density (MVD) determined by CD34, and p53. RESULTS: L-type amino-acid transporter 1 and 4F2hc were highly expressed in 61% (52 out of 85) and 45% (38 out of 47), respectively. ASC amino-acid transporter-2 and xCT were positively expressed in 59% (50 out of 85) and 21% (18 out of 85), respectively. The expression of both LAT1 and ASCT2 was significantly associated with disease staging, lymph-node metastasis, lymphatic permeation, 4F2hc expression and cell proliferation (Ki-67). xCT expression indicated a significant association with advanced stage and tumour factor. By univariate analysis, disease staging, lymphatic permeation, vascular invasion, LAT1, ASCT2, 4F2hc, and Ki-67 had a significant relationship with overall survival. Multivariate analysis confirmed that LAT1 was an independent prognostic factor for predicting poor prognosis. CONCLUSIONS: L-type amino-acid transporter 1 and ASCT2 can serve as a significant prognostic factor for predicting worse outcome after surgical treatment and may have an important role in the development and aggressiveness of tongue cancer.

ASC amino-acid transporter 2 (ASCT2) as a novel prognostic marker in non-small cell lung cancer.

BACKGROUND: ASC amino-acid transporter 2 (ASCT2) is a major glutamine transporter that has an essential role in tumour growth and progression. Although ASCT2 is highly expressed in various cancer cells, the clinicopathological significance of its expression in non-small cell lung cancer (NSCLC) remains unclear. METHODS: One hundred and four patients with surgically resected NSCLC were evaluated as one institutional cohort. Tumour sections were stained by immunohistochemistry (IHC) for ASCT2, Ki-67, phospho-mTOR (mammalian target of rapamycin), and CD34 to assess the microvessel density. Two hundred and four patients with NSCLC were also validated by IHC from an independent cohort. RESULTS: ASC amino-acid transporter 2 was expressed in 66% of patients, and was closely correlated with disease stage, lymphatic permeation, vascular invasion, CD98, cell proliferation, angiogenesis, and mTOR phosphorylation, particularly in patients with adenocarcinoma (AC). Moreover, two independent cohorts confirmed that ASCT2 was an independent marker for poor outcome in AC patients. CONCLUSIONS: ASC amino-acid transporter 2 expression has a crucial role in the metastasis of pulmonary AC, and is a potential molecular marker for predicting poor prognosis after surgery.

Biological significance of fluorine-18-α-methyltyrosine (FAMT) uptake on PET in patients with oesophageal cancer.

PURPOSE: (18)F-FAMT as an amino-acid tracer for positron emission tomography (PET) is useful for detecting human neoplasms. (18)F-FAMT is accumulated in tumour cells solely via L-type amino-acid transporter 1 (LAT1). This study was conducted to investigate the biological significance of (18)F-FAMT uptake in patients with oesophageal cancer. METHODS: From April 2008 to December 2011, 42 patients with oesophageal cancer underwent both (18)F-FAMT PET/CT and (18)F-FDG PET/CT before surgical treatment. The immunohistochemical analysis of LAT1, CD98, Ki-67, CD34, p53, p-Akt and p-mTOR was performed on the primary lesions. In vitro experiments were performed to examine the mechanism of (18)F-FAMT uptake. RESULTS: High uptake of (18)F-FAMT was significantly associated with advanced stage, lymph node metastasis and the expression of LAT1, CD98, Ki-67 and CD34. LAT1 expression yielded a statistically significant correlation with CD98 expression, cell proliferation, angiogenesis and glucose metabolism. In vitro experiments revealed that (18)F-FAMT was specifically transported by LAT1. CONCLUSIONS: The uptake of (18)F-FAMT within tumour cells is determined by the LAT1 expression and correlated with cell proliferation and angiogenesis in oesophageal cancer. The present experiments also confirmed the presence of LAT1 as an underlying mechanism of (18)F-FAMT accumulation.

Prognostic significance of L-type amino-acid transporter 1 expression in surgically resected pancreatic cancer.

BACKGROUND: The expression of L-type amino-acid transporter 1 (LAT1) is tumour-specific and has been shown to have essential roles in cell growth and survival. However, little is known regarding the clinical significance of LAT1 expression in pancreatic cancer. This study was conducted to determine the prognostic significance of LAT1 expression. METHODS: A total of 97 consecutive patients with surgically resected pathological stage I-IV pancreatic ductal adenocarcinoma were retrospectively reviewed. Tumour sections were stained by immunohistochemistry for LAT1, CD98, Ki-67 and vascular endothelial growth factor (VEGF), and microvessel density was determined by CD34 and p53. RESULTS: L-type amino-acid transporter 1 and CD98 were highly expressed in 52.6% (51/97) and 56.7% (55/97) of cases, respectively (P=0.568). The expression of LAT1 within pancreatic cancer cells was significantly associated with disease stage, tumour size, Ki-67, VEGF, CD34, p53 and CD98. L-type amino-acid transporter 1 expression was confirmed to be a significant prognostic factor for predicting poor outcome by multivariate analysis. CONCLUSION: L-type amino-acid transporter 1 expression is a promising pathological marker for the prediction of outcome in patients with pancreatic cancer.

Effects of exercise intensity on the sweating response to a sustained static exercise.

To investigate how the sweating response to a sustained handgrip exercise depends on changes in the exercise intensity, the sweating response to exercise was measured in eight healthy male subjects. Each subject lay in the supine position in a climatic chamber (35 degrees C and 50% relative humidity) for approximately 60 min. This exposure caused sudomotor activation by increasing skin temperature without a marked change in internal temperature. After this period, each subject performed isometric handgrip exercise [15, 30, 45, and 60% maximal voluntary contraction (MVC)] for 60 s. Although esophageal and mean skin temperatures did not change with a rise in exercise intensity and were similar at all exercise intensities, the sweating rate (SR) on the forearm increased significantly (P < 0.05) from baseline (0.094 +/- 0.021 mg. cm(-2). min(-1) at 30% MVC, 0.102 +/- 0.022 mg. cm(-2). min(-1) at 45% MVC, 0.059 +/- 0.009 mg. cm(-2). min(-1) at 60% MVC) in parallel with exercise intensity above exercise intensity at 30% MVC (0.121 +/- 0.023 mg. cm(-2). min(-1) at 30% MVC, 0.242 +/- 0.051 mg. cm(-2). min(-1) at 45% MVC, 0.290 +/- 0.056 mg. cm(-2). min(-1) at 60% MVC). Above 45% MVC, SR on the palm increased significantly from baseline (P < 0.05). Although SR on the forearm and palm tended to increase with a rise in exercise intensity, there was a difference in the time courses of SR between sites. SR on the palm showed a plateau after abrupt increase, whereas SR on the forearm increased progressively during exercise. These results suggest that the increase in SR with the increase in sustained handgrip exercise intensity is due to nonthermal factors and that the magnitude of these factors during the exercise may be responsible for the magnitude of SR.

Cloning and characterization of a vasa-like gene in rainbow trout and its expression in the germ cell lineage.

The origin of germ cells and the molecular mechanisms of primordial germ cell (PGC) determination in teleosts are unclear. Vasa is a member of the DEAD protein family and plays an indispensable role in germ cell determination in Drosophila and Xenopus species. In this study, we isolated and characterized a rainbow trout vasa cDNA as a first step towards understanding the molecular mechanisms of PGC determination and development and to develop a molecular marker to identify the PGCs in rainbow trout. Cloning of vasa cDNA was performed by degenerate- and RACE-PCR. The predicted amino acid sequence of rainbow trout Vasa contained eight consensus sequences for the DEAD protein family and five arginine-glycine-glycine repeats, a common character of known Vasa homologues. Overall amino acid similarity to the Vasa of Drosophila was 79.2%. Whole-mount in situ hybridization of eyed stage embryos (eighty somite stage) revealed that signals were localized to the putative PGCs. In adult rainbow trout tissues, both ovaries and testes contained large amounts of vasa gene transcripts. A reverse transcription-polymerase chain reaction analysis of unfertilized eggs proved that trout vasa is a maternal factor. Although we have not determined whether rainbow trout vasa functions as a germ cell determinant, its limited expression in the germ cell lineage proved that rainbow trout vasa can be used as a marker molecule for PGCs. This marker will make it possible to identify the PGCs or presumptive PGCs in early trout embryos whose germ cells can not be distinguished by morphological characteristics.

[Invasive amebiasis at an institution for the mentally retarded in Hyogo Prefecture].

An outbreak of amebiasis caused by Entamoeba histolytica occurred at an institution for mentally retarded persons in Hyogo Prefecture. Twelve out of a total of 49 admitted persons exhibited E. histolytica cysts in their stool, and 13 including persons in whom no cysts had been detected showed positive serological reactions for E. histolytica infection. However, neither the cyst nor the antibody against the organism was detected in the staff members of the institution. Indirect fluorescence antibody test and sandwich enzyme-linked immunosorbent assay with a monoclonal antibody specific for pathogenic strains of E. histolytica revealed that all trophozoite strains grown from cysts in stool samples from five patients were pathogenic. Epidemiological analysis strongly suggested that a patient in the institution had been infected with an organism from a patient outside the institution, and that infection may have spread among the admitted persons due to abnormal behavior. Administration of metronidazole resulted in effective elimination of the cysts from the stool of the cyst-carriers.

Modulation of the thermoregulatory sweating response to mild hyperthermia during activation of the muscle metaboreflex in humans.

1. To investigate the effect of the muscle metaboreflex on the thermoregulatory sweating response in humans, eight healthy male subjects performed sustained isometric handgrip exercise in an environmental chamber (35 C and 50 % relative humidity) at 30 or 45 % maximal voluntary contraction (MVC), at the end of which the blood circulation to the forearm was occluded for 120 s. The environmental conditions were such as to produce sweating by increase in skin temperature without a marked change in oesophageal temperature. 2. During circulatory occlusion after handgrip exercise at 30 % MVC for 120 s or at 45 % MVC for 60 s, the sweating rate (SR) on the chest and forearm (hairy regions), and the mean arterial blood pressure were significantly above baseline values (P < 0.05). There were no changes from baseline values in the oesophageal temperature, mean skin temperature, or SR on the palm (hairless regions). 3. During the occlusion after handgrip exercise at 30 % MVC for 60 s and during the occlusion alone, none of the measured parameters differed from baseline values. 4. It is concluded that, under mildly hyperthermic conditions, the thermoregulatory sweating response on the hairy regions is modulated by afferent signals from muscle metaboreceptors.

Regional differences in the effect of exercise intensity on thermoregulatory sweating and cutaneous vasodilation.

To investigate regional body differences in the effect of exercise intensity on the thermoregulatory sweating response, nine healthy male subjects (23.2 +/- 0.4 year) cycled at 35, 50 and 65% of their maximal O2 uptake (VO2max) for 30 min at an ambient temperature of 28.3 +/- 0.2 degrees C and a relative humidity of 42.6 +/- 2.4%. Local sweating rate (msw) on the forehead, chest, back, forearm and thigh increased significantly with increases in the exercise intensity from 35 to 50% VO2max and from 50 to 65% VO2max (P < 0.05). The mean values for the density of activated sweat glands (ASG) at 50 and 65% VO2max at the five sites were significantly greater than at 35% VO2max. The mean value of the sweat output per gland (SGO) also increased significantly with the increase in exercise intensity (P < 0.05). The patterns of changes in ASG and SGO with an increase in exercise intensity differed from one region of the body to another. Although esophageal temperature (Tes) threshold for the onset of sweating at each site was not altered by exercise intensity, the sensitivity of the sweating response on the forehead increased significantly from 35 to 50 and 65% VO2max (P < 0.05). The threshold for cutaneous vasodilation tend to increase with exercise intensity, although the exercise intensity did not affect the sensitivity (the slope in the relationship Tes vs. percentage of the maximal skin blood flow) at each site. Tes threshold for cutaneous vasodilation on the forearm was significantly higher at 65% VO2max than at either 35 or 50% VO2max, but this was not observed at the other sites, such as on the forehead and chest. These results suggest that the increase in msw seen with an increasing intensity of exercise depends first on ASG, and then on SGO, and the dependence of ASG and SGO on the increase in msw differs for different body sites. In addition, there are regional differences in the Tes threshold for vasodilation in response to an increase in exercise intensity.

Continuous measurement of tympanic temperature with a new infrared method using an optical fiber.

The purpose of this study was to investigate the utility of an infrared tympanic thermometry by using an optical fiber for measuring tympanic temperature (Tty). In the head cooling and facial fanning tests during normothermia, right Tty measured by this method (infrared-Tty) and esophageal temperature (Tes) were not affected by decreased temple and forehead skin temperatures, suggesting that the infrared sensor in this system measured the infrared radiation from the tympanic membrane selectively. Eight male subjects took part in passive-heat-stress and progressive-exercise tests. No significant differences among infrared-Tty, the left Tty measured by thermistor (contact-Tty), and Tes were observed at rest or at the end of each experiment, and there was no significant difference in the increase in these core temperatures from rest to the end. Furthermore, there were no significant differences in the core temperature threshold at the onset of sweating and slope (the relationship of sweating rate vs. infrared-Tty and vs. contact-Tty). These results suggest that this method makes it possible to measure Tty accurately, continuously, and more safely.

A Case of Breast Cancer Coexisting with Florid Papillomatosis of the Nipple.

We report a 47 year-old woman with a unique breast cancer coexisting with florid papillomatosis (FP) of the left nipple. The diseased nipple was enlarged and reddened. There was an area of erosion on the surface. Incisional biopsy revealed FP of the nipple. Under the nipple, there was an elastic hard tumor with an unclear border and irregular surface. Aspiration biopsy cytology of the tumor revealed carcinoma. Modified radical mastectomy was performed. Histological examination showed that the superior portion of the tumor was FP, and most of the tumor in and under the nipple was breast cancer. To the best of our knowledge, only 16 cases of FP of the nipple have been reported in the Japanese literature. FP of the nipple coexisting with carcinoma in the same nipple has never been reported. This is thought to be the first case in Japan of mammary carcinoma coexisting with FP in the same nipple.

3D and 4D atlas system of living human body structure.

A reference system for accessing anatomical information from a complete 3D structure of the whole body "living human", including 4D cardiac dynamics, was reconstructed with 3D and 4D data sets obtained from normal volunteers. With this system, we were able to produce a human atlas in which sectional images can be accessed from any part of the human body interactively by real-time image generation.

Circadian variation of sweating responses to passive heat stress.

The aim of present study was to examine whether sweating responses to passive heat stress change with the circadian rhythm of internal temperature. Six men had their legs immersed in water at 42 degrees C for 60 min in an ambient temperature of 28 degrees C on four separate days. Experiments were conducted at four different times [06.00 h (morning), 12.00 h (daytime), 18.00 h (evening) and 24.00 h (night)]. We measured oesophageal temperature (Toes), mean body temperature (Tb), local sweating rate (msw) on the forehead, back, forearm and thigh, the densities of activated sweat gland (ASG) on the back, forearm and thigh, and the frequency of sweat expulsion per minute (Fsw) which has been suggested to represent central sudomotor activity. Sweat gland output (SGO) on each site was calculated by dividing msw by ASG. ASG was significantly higher on the forearm than on the back and thigh, and SGO was significantly lower on the forearm than on the back and thigh. However, ASG and SGO did not significantly change over the day. Tb and Toes thresholds for the onset of sweating showed a significant change with both the temperature rhythms at rest prior to each procedure, while the slopes of the relationships Fsw-Tb and msw-Fsw showed no significant difference over the day. We suggest that the circadian variation of sweating response to passive heat stress is regulated by a central sudomotor mechanism rather than by sweat gland function.

An adult case of duodenal anomaly.

A distal gastrectomy reconstruction using the Billroth II procedure was performed for epigastralgia and liver dysfunction caused by a duodenal anomaly in an adult. Hypotonic duodenography revealed the duodenum to be obliterated at the junction of the second and third portion, while the third portion was joined to the first portion. Endoscopic retrograde cholangiopancreaticography (ERCP) and ultrasonography showed a normal construction of the common bile and pancreatic ducts, as well as gallstones. To prevent ingested food from the stomach from entering the obliterated second portion, a distal gastrectomy (Billroth II) was thus performed. The patient has remained asymptomatic for 4 years since surgery. A distal gastrectomy reconstructed by a gastrojejunostomy is thus considered to be an effective method for improving the symptoms caused by food stasis in the obliterated second portion of the duodenum.

A combined assay of cell viability and in vitro cytotoxicity with a highly water-soluble tetrazolium salt, neutral red and crystal violet.

Cell viability and in vitro cytotoxicity assay methods were developed using a combination of dyes, 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1), neutral red (NR) and crystal violet (CV), with HeLa cells as a bioindicatior. As WST-1 produces a highly water soluble and non-cytotoxic formazan dye, ti allows each assay to be carried out in one culture dish. The combined cell viability assay using WST-1, NR and CV gave an absorbance that correlated linearly with the number of cells over the range 1000 to 50,000 cells/well. The combined assay was applied to the evaluation of IC50 values for sodium dodecyl sulfate as a model toxicant, which yielded similar values to those obtained with each assay independently.

Structure and replication of cryptic plasmids, pMA1 and pMA2, from a unicellular cyanobacterium, Microcystis aeruginosa.

The 4993-bp cryptic plasmid, pMA2, from a cyanobacterium, Microcystis aeruginosa f. aeruginosa Kützing, originally derived from Kasumigaura lake, was completely sequenced and analyzed. Plasmid pMA2 had a unique sequence motif CTTGATT, which was proposed to be a nicking site on the smaller plasmid pMA1 (2287-bp) by the presence of single-stranded DNA susceptible to S1 nuclease. We had detected the occurrence of the single-stranded pMA1 in the living M. aeruginosa cells. This was also the case of pMA2. Thus, we suggest that both plasmids, pMA1 and pMA2, replicate through the rolling circle mechanism. By computer analysis of the pMA2 sequence, two open reading frames were found: one had a predicted molecular size of 30,440 Da and the other on a complementary one had a predicted molecular size of 10,852 Da. No rep protein was detected. Replication mechanisms of the plasmids are discussed.

Secretion of gastric inhibitory polypeptide in patients with bile duct obstruction.

BACKGROUND: The direct contribution of bile to gastric inhibitory polypeptide (GIP) release and the role of bile in regulating GIP secretion in response to fat ingestion are still obscure. The present study was aimed to clarify the influence of bile on GIP release. METHODS: Seven patients with obstruction of the common bile duct and nine volunteers participated in the study. Fifty milliliters of Lipomul was ingested, and GIP was measured serially for 180 min. After intraduodenal instillation of pooled autologous bile for 2 days, the same study was carried out. RESULTS: The fat-stimulated GIP response was significantly lower in the patients than in the controls. The basal GIP level did not change on bile instillation, but the GIP response to fat ingestion was significantly increased on bile instillation compared with that in the absence of bile. CONCLUSIONS: Intraluminal bile alone does not stimulate the secretion of GIP, but it promotes GIP secretion in response to fat ingestion.

Sequence evolution of the Gpdh gene in the Drosophila virilis species group.

The nucleotide sequence of the Gpdh gene from six taxa, D. virilis, D. lummei, D. novamexicana, D. a. americana, D. a. texana and D. ezoana, belonging to the virilis species group was determined to examine details of evolutionary change in the structure of the Gpdh gene. The Gpdh gene is comprised of one 5' non-translated region, eight exons, seven introns and three 3' non-translated regions. Exon/intron organization was identical in all the species examined, but different from that of mammals. Interspecific nucleotide divergence in the entire Gpdh gene followed the common pattern: it was low in the exon, high in the intron and intermediate in the non-translated regions. The degree of nucleotide divergence differed within these regions, suggesting that selection exerts constraints differentially on nucleotide change of the Gpdh gene. A phylogenetic tree of the virilis phylad constructed from nucleotide variation of total sequence was consistent with those obtained from other data.