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Biomedical subjects

M Ata

Publications and source records attributed to M Ata.

At least 19 recordsLinked to original sources
PubMed2005

Large optical nonlinearity of semiconducting single-walled carbon nanotubes under resonant excitations.

We measured third-order nonlinear susceptibility (chi(3)) spectra in semiconducting single-walled carbon nanotubes (SWNTs) by the Z-scan method. |Imchi(3)| is remarkably enhanced under resonant excitation to the lowest interband transition, reaching 4.2 x 10(-6) esu and 1.5 x 10(-7) esu in SWNTs grown by the laser ablation and HiPco methods, respectively. A comparison of the transient absorption changes evaluated by degenerate and nondegenerate pump-probe measurements suggests that the resonant enhancement of |Imchi(3)| is dominated by a coherent process rather than by saturation of absorption.

Journal Article↗
PubMed2004

Postoperative radiotherapy-induced morbidity in rectal cancer.

OBJECTIVES: We analyzed long-term morbidity and bowel function alteration after postoperative radiotherapy for rectal cancer following resection with anastomosis. PATIENTS AND METHODS: Thirty-seven patients who underwent surgery with intention to cure and a minimal follow-up period of 3 years were included. These patients were divided into two groups: in the first group, 14 patients received postoperative chemo-radiotherapy, 5-fluorouracil plus folinic acid, and 45 Gy plus 5 Gy boost. In the second group, there were 23 patients regarded as controls. We designed a questionnaire about their bowel function and analyzed the morbidity detected in their follow-up. RESULTS: The group that was treated with postoperative chemo-radiotherapy had more daily bowel movements (p = 0.03) and night-time movements (p = 0.04); incontinence (69.2 vs. 17.4% in the control group; p = 0.002), and perianal skin irritation (p = 0.04) versus the control group. Although without meaningful differences, the group under treatment wore a pad more often, had more defecatory urgency, could distinguish worse gas from stool, and needed more frequently antidiarrheal measures. Major complications were present in 28.6% of the under-treatment group: three intestinal resections were performed due to actinic stenosis; one patient had a residual stercoral fistula; another had several occlusive crises solved with medical treatment. CONCLUSIONS: Postoperative chemo-radiotherapy had a high morbidity rate, which determined a significant alteration in quality of life. Accuracy in indication is therefore necessary, as well as a consideration of other alternatives for treatment, such as preoperative chemo-radiotherapy and total mesorectal excision.

Aged↗
PubMed1996

Evaluating the detection of circulating filarial antigen in diagnosis of bancroftian filariasis and filarial hydrocele.

Four groups of patients were selected: 16 patients with clinical evidence of obstructive filarial lymphangiopathy without microfilaraemia; 12 patients with clinical evidence of obstructive filarial lymphangiopathy with microfilaraemia and 9 patients with microfilaraemia. Two control groups were also included. Blood films, sera and hydrocele fluid samples were collected from all subjects. Polyclonal antibody against Dirofilaria immitis worm homogenate was prepared, fractionated and conjugated with HRP. Both polyclonal antibody and monoclonal antibody (AD12) were used in a sandwich ELISA. Using polyclonal antibody, both microfilaraemic groups (groups 2 and 3) had a significantly higher mean O.D. readings than that of control groups (P < 0.05), whereas, the mean O.D. readings of patients with symptomatic amicrofilaraemia had no significant difference than control groups. Symptomatic microfilaraemic group had the highest percentage of antigen positivity 7/12 (58.3%) among all groups while symptomatic amicrofilaraemic group had the least antigen positivity 2/16 (12.5%). Patients presented with elephantiasis only or with hydrocele had no antigen positive levels 0/12 (0%) in their serum or hydrocele fluid samples. On the other hand, 2 out of 4 cases represented with hydrocele (50%) had positive antigen levels in their hydrocele fluid samples. Using monoclonal antibody, all groups had a highly significant higher mean optical density readings than control groups. Asymptomatic microfilaraemic group had the highest percentage of antigen positivity 8/9 (88.9%), followed by symptomatic microfilaraemic 8/12 (66.7%), then symptomatic amicrofilaraemic group 4/16 (25%). The same 2 patients (amicrofilaraemia) and 7 (microfilaraemia) represented with hydrocele had positive antigen levels in their hydrocele fluid samples.

Animals↗
PubMed1994

[The evaluation of the newly produced assay kit for the cytokeratin fragment, "ball ELSA CYFRA21-1"].

We evaluated the newly produced tumor marker assay kit, "Ball ELSA CYFRA21-1", which detects cytokeratin 19 fragment in the sera of patients with malignancies, especially lung cancers. The assay procedure is simple based on the one-step radioimmunometric assay method. The measured values depend somewhat on incubation temperature and time. Reproducibility and recovery were good. The minimum measurable level was 1 ng/ml. The dilution test was satisfactory. The CYFRA21-1 levels were gradually decreased by repeated freezing and thawing and after seven such exercises its activity dropped to about 70% of that of first assay. The presence of CYFRA21-1 antigen was strongly correlated with TPA antigen and, although some discrepancies could be observed in clinical samples, CYFRA21-1 activity was completely absorbed by anti-TPA antibody-coated beads in one sample. CYFRA21-1 levels of 44 normal controls were below 1.0 ng/ml. Assuming a cut-off value of 2.0 mg/ml, 32.7% of all cases with benign disease had values greater than 2.0 ng/ml. This fell to 21.4% on exclusion of cases of interstitial pulmonary disease. Those with malignant diseases had high CYFRA21-1 levels whether associated with lung cancer or not. The most high positive ratios were observed in squamous cell lung cancer, small cell lung cancer, and uterine cervical cancer. In conclusion, CYFRA21-1 may be a good tumor marker comparable to TPA not only for lung cancer but also other malignancies as well. High false positives for lung cancer, however, were observed in other pulmonary diseases.

Adolescent↗
PubMed1988

[An immunoradiometric assay of serum SCC antigen using a monoclonal antibody--a comparison with the conventional double antibody method].

The serum level of the squamous cell carcinoma-related antigen (SCC-Ag) has been measured by a new immunoradiometric assay (IRMA) method that has been recently developed by using a monoclonal antibody, and compared with the results obtained by the conventional double-antibody method using a polyclonal antibody. Both methods gave essentially the same results, that the serum SCC-Ag level was high in patients with squamous cell carcinoma of various organs when compared with other types of lung cancer or benign diseases. However, the percentages of the serum SCC-Ag level over the normal range were found to be higher by the new IRMA method than by the conventional method. This may be due to the improvement in sensitivity and accuracy of this newer method of assay, which also results in a considerable decrease in the normal range estimated in healthy subjects. Therefore, it has been concluded that this new method is more suitable than the conventional method for an early diagnosis of squamous cell carcinoma in all organs.

Antigens, Neoplasm↗