[Enterohemorrhagic Escherichia coli (EHEC) infection in infants and children]

In the past 10 years, enterohemorrhagic Escherichia coli (EHEC) infection in infants and children has not been decreased in Japan. Clinical manifestations may include history of diarrhea, a visibly bloody stool, fever, and abdominal tenderness those last for about 2 weeks and restore naturally. However, if the patients suffer from hemolytic uremic syndrome (HUS) that may be fatal infrequently. The major treatment for EHEC infection and HUS have been therapies for these symptons. Therefore new therapeutic agents for vero toxin (VT) have been developed, but that is still experimental. We describe the latest clinical researches and treatment strategies in this paper.

Microarray analysis of gastric mucosa among children with Helicobacter pylori infection

BACKGROUND

Although initial infection with Helicobacter pylori may occur before 5 years of age, the pediatric mucosal immune response against H. pylori is not clear. The aim of the present study was to evaluate immune responses in the H. pylori-infected gastric mucosa of children using microarray and real-time polymerase chain reaction (PCR) analysis of pediatric gastric samples.

METHODS

Gastric samples were obtained from 12 patients undergoing routine endoscopy of chronic abdominal complaints. Six patients (three boys, three girls) aged 10.1-14.6 years had evidence of H. pylori infection, and the remaining six (three boys, three girls) aged 10.3-15.5 years had no evidence of infection and presented no histological changes associated with gastritis. Microarray and real-time PCR analyses were performed, and the changes in gene expression-related immune response were also analyzed.

RESULTS

Using microarray analysis, the total number of significantly upregulated and downregulated genes (fold change >5, P < 0.01) was 21 in the antrum and 16 in the corpus when comparing patients with or without infection. Using real-time PCR, the expression of lipocalin-2 (Lcn2), C-C motif chemokine ligand (CCL) 18, C-X-C motif chemokine ligand (CXCL) 9 and CXCL11 was upregulated, while the expression of pepsinogen (PG) I and PGII was downregulated when comparing patients with or without infection.

CONCLUSIONS

 Lcn2, CCL18, CXCL9, CXCL11, PGI and PGII play important roles in childhood H. pylori infection.

Risk of breast cancer among Japanese women with a positive family history

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Background: Most breast cancer cases are sporadic, rather than associated with inherited gene mutations, such as BRCA1 and BRCA2. However, women with a family history of breast cancer are at increased risk of developing breast cancer compared to those women without any family history, even if they lack these gene mutations.

Methods: We analyzed 10892 patients including bilateral breast cancer cases (total of 11398 breast cancers) who underwent surgery at our hospital between 1962 and 2009. We excluded 295 cases whose family history data were not available. Clinical and pathological differences between following patient groups were tested; 9528 patients or 9955 cancers (88%) with negative family history (FH-), 896 patients or 951 cancers (8%) who had at least one first-degree relative with breast cancer (1FH+), 468 patients or 492 cancers (4%) who had second-degree relative with breast cancer (2FH+), and 1364 patients or 1443 cancers (12%) with family history regardless of first- or second-degree relative (FH+). Significance was established at a p-value of < 0.05.

Results: Among the family members, sisters were more likely to have treated for breast cancer (38% in FH+ group), followed by mothers (27%), aunts (26%), grandmothers (7%), and daughters (2%). The incidence of developing contralateral breast cancer was significantly higher in 1FH+ group, compared to patients in FH- and 2FH+ groups. No other factors showed any significant difference, including the incidence of cancer in other organs, pathological characteristics, and age of onset, although BRCA1 and BRCA2 mutation may be associated with increased risk of developing breast cancer at younger age. Outcome studies with available data did not show any significant difference in overall survival between FH+ and FH- patients.

Conclusions: A Japanese woman with a positive family history has a higher risk of developing breast cancer than women without any close relatives with breast cancer, similar to the results reported in Western countries where prevalence of breast cancer is higher. Regular checkup of contralateral breast is important for those patients whose first-degree relatives have also been diagnosed with breast cancer.

Study of sentinel lymph node biopsy after preoperative chemotherapy in patients with breast cancer

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Background: Despite the increasing use of both sentinel lymph node biopsy (SLNB) and preoperative chemotherapy (PST) in patients with operable breast cancer, there is still limited information on the feasibility and accuracy of SLNB following PST. In this study, the feasibility and accuracy of SLNB for breast cancer patients with clinically negative lymph nodes after PST were investigated. In addition, conditions that may affect SLN biopsy detection and false-negative rates with respect to clinical tumor response and clinical tumor/nodal status before PST were analyzed.

Methods: Between 2003 and 2008, 200 patients with stage II and III breast cancer previously treated with PST were enrolled in this study. The eligible criteria for PST were (a) primary tumor > 3cm or (b) positive axillary lymph node status on initial examination. FNA biopsy was performed for clinically or ultrasonographically suspicious axillary lymph nodes. The patients then underwent SLNB, which involved a combination of intradermal injection over the tumor of radiocolloid and subareolar injection of blue dye. This was followed by Level I/II axillary lymph node dissection (ALND).

Results: The median patient age was 49 years, and the median primary tumor size was 4.9 cm. The overall SLN identification rate was 94.5% (189 of 200). In 178/189 patients (94%) the SLN accurately predicted the axillary status. Eleven patients had a false-negative SLN biopsies, yielding a false-negative rate of 12.9%. There were no significant differences in the SLN identification rate according to tumor classifications before PST, the clinical nodal status before PST, the clinical tumor response after PST, or pathological response of the tumor after PST, although the SLN identification rate tended to be lower in patients with a T4 primary tumor.

Conclusions: Our data and some reports suggested that SLNB was feasible method for axillary staging in breast cancer patients who received PST even in patients who initially with lymph node positive disease. However, false-negative rate of SLNB in patients with clinical and pathological complete tumor response tended to be higher than other group.

Lack of histamine alters gastric mucosal morphology: comparison of histidine decarboxylase-deficient and mast cell-deficient mice

Histamine plays an important role in the regulation of gastric acid secretion; however, its role in maintenance of gastric morphology remains unclear. To clarify the necessity of histamine for gastric mucosal development and maintenance, we evaluated two different kinds of mice that lacked either mast cells (one of the gastric histamine-producing cell types) or histidine decarboxylase (HDC; a histamine-synthesizing enzyme). Measurements of stomach weight, intragastric pH, mucosal histamine levels, as well as serum gastrin and albumin levels were performed in mice. Gastric mucosal appearance was examined by immunohistochemical techniques. Although gastric mucosal histamine levels in mast cell-deficient mice were half of those observed in the wild-type mice, intragastric pH, serum gastrin levels, and gastric morphology at 12 mo were unchanged compared with the wild-type mice. In contrast, HDC-deficient mice possessed no detectable gastric histamine, but did exhibit hypergastrinemia, as well as marked increases in intragastric pH and stomach weight compared with the wild-type mice. Histological analysis revealed that 9-mo-old HDC-deficient mice demonstrated hyperplasia in the oxyntic glandular base region, as well as increased numbers of parietal and enterochromaffin-like cells. These results indicate that enterochromaffin-like cell-derived histamine is potentially involved in gastric mucosal morphology regulation.

Separation of a process from the neuronal cell body using a thin aluminum foil separator

A new technique using a simple-structured separator is described to separate the end of the process from the cell body (soma) of cultured cells. By this method, stimulation limited to neuronal processes is experimentally possible. The separator is of an oblong shape and consists of two parts: a square bracket-shaped frame made of Teflon and a thin aluminum foil which is stuck on both free ends of frame (bracket) coated with epoxy-resin. The separator is horizontally placed on the dish under microscope to divide the process on the way, so that the free end of the process is outside the oblong separator. This separator is simple and low cost, and does not need a long process, unlike other methods requiring a special culture dish with a micro-groove for growth of the neuronal process (neurite). The new technique could be useful in basic pain research and neurophysiology.

Suppressive effects of low-power laser irradiation on bradykinin evoked action potentials in cultured murine dorsal root ganglion cells

The effects of Ga-Al-As diode laser (830 nm, 16.2 mW) irradiation on the distal portion of the processes of cultured murine dorsal root ganglion (DRG) neurons associated with C-fibers were studied by patch-clamp whole-cell recording of membrane potentials at the cell body. The chemical as well as laser light stimulations were limited to the processes of the neuron isolated from the cell body with a separator. The action potentials elicited by bradykinin (BK) in the cell body were reversibly suppressed by the irradiation of laser light. The laser irradiation may block the conduction of nociceptive signals in primary afferent neurons. The present experimental method offers a simple and easy to use procedure for studying the pain relief effects by laser irradiation.