Urinaryα 1 as an index of proximal tubular function in early infancy

Urinary ₁-microglobulin (U-A₁M) was measured in healthy term infants on days 1, 4, 7, 14, 28, 90 and 180 of life. U-A₁M was high until day 14 and declined thereafter. It was significantly correlated with urinary ₂-microglobulin (U-B₂M) throughout the study, but not with serum A₁M on days 1 or 7. Similar to U-B₂M, U-A₁M in the clinically stable term infants with intrauterine growth retardation (n=4–7) was not elevated on days 1–7. In the sick infants who needed immediate resuscitatio at birth (n=4–8), U-A₁M as well as U-B₂M was high on days 1–7 and then decreased to normal levels, suggesting that U-A₁M can be used as a sensitive marker of acute proximal tubular damage and its recovery. These observations indicate that U-A₁M is a useful index of proximal tubular function in early infancy.     

Postsynaptic expression of Ca2+-permeable AMPA-type glutamate receptor channels by viral-mediated gene transfer

The ability to artificially express a particular receptor protein in the postsynaptic sites of neurons in the central nervous system (CNS) would be useful for the study of synaptic function of cloned receptor genes as well as for gene therapy of neurological disorders caused by dysfunction of postsynaptic receptors. In this study, we aimed to express the cDNA of unedited GluR2 subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor that forms inwardly rectifying and Ca2+-permeable channel in CNS neurons by using adenoviral-mediated gene transfer. For this purpose, we have constructed a recombinant adenovirus bearing an expression-switching unit, where the unedited GluR2 cDNA can be activated by the Cre recombinase-mediated excisional deletion of a stuffer DNA interposed between the promotor and the coding region. When PC12 cells were infected with this recombinant adenovirus together with an adenovirus expressing Cre recombinase, the inwardly rectifying and Ca2+-permeable AMPA receptor channels were expressed in nearly 100% of infected cells. Two days after co-infection of cultured rat hippocampal neurons with these adenoviruses, fast excitatory neurotransmission in the glutamatergic synapse was mediated predominantly by the inwardly rectifying and Ca2+-permeable AMPA receptor channels. This indicates that the native AMPA receptors in the postsynaptic sites of the glutamatergic synapse are replaced rapidly with recombinant receptors newly produced by the viral-mediated gene transfer.     

Comparison of two-year and five-year tamoxifen use in Japanese post-menopausal women

AIM: Large multicenter, randomized trials have revealed the advantages of using tamoxifen for 5 years vs 2 years in breast cancer patients. The aim of this report is to confirm the optimal duration of tamoxifen administration in a study of Japanese breast cancer patients. METHODS: Japanese post-menopausal estrogen receptor-positive breast cancer patients treated with mastectomy were randomly assigned to either a 5-year or 2-year course of tamoxifen. The primary endpoint was disease-free survival, with secondary endpoints of overall survival and a reduction in the development of metachronous contra-lateral breast cancer. RESULTS: A total of 256 breast cancer patients were randomized to a 5-year or 2-year tamoxifen administration group. After a median follow-up time of 81 months, there were no significant differences seen in terms of disease-free or overall survival (p=0.65 and 0.56, respectively). Furthermore, the impact of the 5-year use of tamoxifen on the development of contra-lateral breast cancer did not reach statistical significance (p=0.0511). However, 5-year tamoxifen use was closely associated with gynaecological complications (p=0.0081). CONCLUSION: We could not show a beneficial effect of using tamoxifen for 5 years over 2 years in Japanese estrogen receptor-positive patients. This is likely due to the small number of patients enrolled in our study; however, racial disparity may influence this result. A reevaluation is necessary to study the advantages of the 5-year use of tamoxifen in the Japanese racial subgroup.     

Neuronal loss and neurofibrillary degeneration in the hippocampal cortex in late-onset sporadic Alzheimer's disease

To explore more fully the relationship between neuronal death and neurofibrillary degeneration, unaffected neurons, intracellular neurofibrillary tangles (i-NFT) and extracellular NFT (e-NFT) in 22 patients with late-onset sporadic Alzheimer's disease (AD) were morphometrically evaluated in eight subdivisions of the hippocampal cortex, using the Gallyas hematoxylin-eosin stain. The subdivisions examined included CA4, CA3, CA2, CA1 (CA: cornu ammonis), prosubiculum (PRO), subiculum and presubiculum (PRE), parasubiculum (PARA) and the entorhinal cortex (ENT). The unaffected neuron density was significantly lower and both i-NFT and e-NFT densities were significantly higher in subdivisions other than CA4 and CA3 in AD patients compared with those in the aged controls. Unaffected neuron density was significantly, inversely correlated with e-NFT density and with total NFT density in all subdivisions except for PRE in AD patients. Especially in CA2, CA1, PRO and ENT, there were strong correlations between the neuron density and these NFT densities. Both unaffected neuron and e-NFT densities in CA1 and ENT were significantly correlated with the disease duration. The i/e-NFT ratio, an index of the degree and/or rate of progress of neuronal death via neurofibrillary degeneration, showed the lowest value in ENT in AD patients. The findings suggest that neuronal death via neurofibrillary degeneration starts earliest and/or most rapidly progresses in ENT. Furthermore, the i/e-NFT ratios in both ENT and CA1 were significantly correlated with the disease duration, suggesting that the neuronal death pattern in the two subdivisions parallels disease progression.     

Label‐free multiphoton excitation imaging as a promising diagnostic tool for breast cancer

Histopathological diagnosis is the ultimate method of attaining the final diagnosis; however, the observation range is limited to the two‐dimensional plane, and it requires thin slicing of the tissue, which limits diagnostic information. To seek solutions for these problems, we proposed a novel imaging‐based histopathological examination. We used the multiphoton excitation microscopy (MPM) technique to establish a method for visualizing unfixed/unstained human breast tissues. Under near‐infrared ray excitation, fresh human breast tissues emitted fluorescent signals with three major peaks, which enabled visualizing the breast tissue morphology without any fixation or dye staining. Our study using human breast tissue samples from 32 patients indicated that experienced pathologists can estimate normal or cancerous lesions using only these MPM images with a kappa coefficient of 1.0. Moreover, we developed an image classification algorithm with artificial intelligence that enabled us to automatically define cancer cells in small areas with a high sensitivity of ≥0.942. Taken together, label‐free MPM imaging is a promising method for the real‐time automatic diagnosis of breast cancer.     

The potential for oral combination chemotherapy of 5'-deoxy-5-fluorouridine, a 5-FU prodrug, and cyclophosphamide for metastatic breast cancer

Preclinical studies have demonstrated the synergistic anti-tumour activity of combination therapy with the oral cytostatics, 5'-deoxy-5-fluorouridine (5'-DFUR) and cyclophosphamide (CPA), in human breast cancer xenograft models. This study was performed to evaluate the efficacy and safety of this oral combination chemotherapy in the treatment of metastatic breast cancer. In all, 101 patients with metastatic breast cancer were enrolled in the study, and the data for 94 eligible patients of these were evaluated. The patients received twice daily oral combinations of 5'-DFUR (1200 mg/body/day) and CPA (100 mg/body/day) for 2 weeks, followed by a 1-week rest period. After a median of 19 treatment cycles (range 1-66 cycles), 16 patients (17.0%) had a complete response, and 40 patients (42.6%) had partial responses. The response rate was 59.6% (95% CI, 49.0-69.6%). The median time to progression and overall survival times were 11.7 and 40.3 months, respectively. The toxicity was mild and tolerable, and the related grade 3/4 clinical adverse effects consisted of haematological toxicity in 21 patients (22%) and nonhaematological toxicity in five patients (5%). These results suggest that the oral combination chemotherapy of 5'-DFUR and CPA has low toxicity and is a novel, very convenient and effective treatment for metastatic breast cancer.