Design of a DICOM image-based program for estimating patient exposure dose in computed tomography.

During the past decade, there has been a notable worldwide increase in the number of computed tomographic (CT) examinations. Since the radiation exposure to the patient during CT examinations is relatively high, it is important to optimize the dose so that it is set as low as possible but remains consistent with the required diagnostic image quality. Therefore we have developed a Digital Imaging and Communications in Medicine (DICOM) image-based program that calculates organ dose and effective dose values corresponding to tube current modulation. The values for primary radiation were derived from manufacturer specifications with international recommendations and from reference values (ICRP publication 60). Based on these values, organ doses can be computed by the program for arbitrary scan protocols in conventional and in spiral CT. In contrast to similar programs for CT dose assessment, our developed program can perform automatic extraction of the scan protocols from the DICOM tag. Users can easily reproduce and recalculate values by loading DICOM data without the requirement for time-consuming work. Additionally, further extensions are planned to our developed software.     

Suturing techniques of individual surgeons —Differences in accuracy and mechanics—

The suturing techniques of fifteen surgeons with similar surgical experience were evaluated with respect to pinpoint accuracy and the force produced while suturing. Subjects were randomly selected from a group of surgeons whose surgical experience ranged from five to six years. Accuracy was determined by the deviated distance between the needle exit and the designated exit. Force was expressed as torques (F) loaded on a needle holder, and included the derivatives (dF/dt) and integrals (IF). Suturing times (T) were also measured. Ten attempts at suturing were allowed, using each of the following two methods: 1) allowing adjustment by wavering the needle to improve accuracy, and 2) suturing without wavering the needle. The differences in technique, on an individual basis, were highly significant. The accuracy and the mechanics, including the maximum F, maximum dF/dt, IF, IF/T, and T, all had a p-value of less than 0.0001. The surgeons’ ranks according to these variables were also concordant, the Kendall’s coefficients of concordance (W) being 0.60 (p=0.002) for suturing done without wavering and 0.56 (p=0.005), for that done with wavering. It was concluded that the surgeons’ skill in suturing techniques differed significantly among individuals and that the surgeons’ ranks according to the variables were also concordant. Thus, formal training in suturing techniques should be established as part of the training of all surgeons.     

Combination Therapy for Intestinal Amebiasis Using an Anti-amebic Drug and Total Parenteral Nutrition —Report of Two Cases—

Abstract: In this study we report on two cases of amebic colitis treated in our hospital. On admission both patients were in a severe state of malnutrition due to intermittent diarrhea which had continued for one month. Both patients suffered from amebic colitis presumably transmitted by homosexual intercourse. A definite diagnosis of amebic colitis was made from both fecal examination and colonoscopic biopsy. After the diagnosis was made, the patients were treated with metronidazole. This medication can eliminate Entamoeba histolytica, although it was insufficient for the treatment of the patients’malnutrition. Therefore we used total parenteral nutrition to treat their malnutrition. It was successful and resulted in their recovery and discharge. These two cases indicate that total parenteral nutrition therapy is useful for supporting the recovery of patients with amebiasis.     

Pneumothorax manifesting primary lung cancer

Pneumothorax is a rare lung cancer manifestation. We report 2 patients in which pneumothorax occurred as a first manifestation of lung cancer. Postoperative lung tissue examination after pneumothorax showed lung cancer by chance. One patient had dissemination suspected due to ruptured bulla with adenocarcinoma. Both immediately underwent additional lobectomy with mediastinal lymphadenectomy after lung cancer was diagnosed, but we detected lung cancer recurrence in the bottom of the pleural cavity on the same side some 11 months after radical surgery in the patient suspected of dissemination. We could resect it completely, followed by adjuvant radiotherapy. The possibility of lung cancer should thus be considered in pneumothorax patients, even if middle-aged.     

An exonuclease possibly involved in the initiation of repair of bleomycin-damaged DNA in mouse ascites sarcoma cells

A protein factor having exonucleolytic activity on bleomycindamagedDNA and providing priming sites for DNA polymerasesexisted ina DNA polymerase ß fraction partially purified byion exchange chromatography from an extract of permeable mouseascites sarcoma (SR-C3H/He) cells. The exonuclease was separatedfrom DNA polymerase ß by singlestranded DNA-cellulosechromatography, and partially characterized. The enzyme is suggestedtobe involved in the initial step of repair of bleomycin-damagedDNA in removing 3' ends (3'-phosphoglycolate termini) of bleomycin-damagedDNA.     

A Novel Somatic Point Mutation of the RET Proto-oncogene in Tumor Tissues of Small Cell Lung Cancer Patients

We examined whether the novel point mutation from GCC (Ala) to GAC (Asp) at codon 664 in exon 11 of RET proto-oncogene, which we had found in two small cell lung carcinoma (SCLC) cell lines, existed in genomic DNA of tumor tissues of the two SCLC patients from whom these SCLC cell lines were derived. Sequence analysis revealed that point mutation identical to that of the SCLC cell lines was present in amplified alleles of single-strand conformational variants in genomic DNA of the tumor tissues, whereas it was not detected in genomic DNA of non-tumor tissues of the patients. These results indicate that this mutation had initially occurred in the SCLC patients and was of somatic origin.     

Liberation of vasoactive substances and its prevention with thromboxane A2 synthase inhibitor in pig liver transplantation

There are multiple causes of liver graft nonfunction in the early post-transplant period. Since a severe microcirculatory disturbance based on ischemia-reperfusion liver injury is considered to be the main underlying pathophysiology, it is suspected that various vasoactive substances are liberated after reperfusion of the graft. In order to investigate this matter, we conducted an experimental study with pig liver allotransplantation. Two groups of animals received donor grafts with or without thromboxane synthase inhibitor (sodium ozagrel), 1.25 mg/kg body weight intravenously, given at the time of liver harvesting. All of the recipient animals in the treatment group (n=10) survived longer than 7 days whereas three of ten animals in the control group died within 7 days. Serum lactate dehydrogenase (LDH) in the recipient serum at 1 h after reperfusion was significantly lower in the treatment group (915.1±167.3 U/l) than in the control group (1264.4±134.7 U/l). Serum thromboxane B₂ (2261.7±1055.7 pg/ml) and endothelin-1 (6.3±2.2 pg/ml) after reperfusion in the treatment group were significantly lower than those in the control group (4220.0±1711.0 pg/ml and 11.2±3.1 pg/ml, respectively). Although serum angiotensin II after reperfusion tended to be lower in the treatment group than in the controls serum renin activity was less than 3 ng/ml in both groups of animals. There were no differences in the plasma endotoxin levels between the two groups. We conclude that the administration of sodium ozagrel to the donor animals provided better graft function in recipients than no such treatment. We speculate that the inhibition of thromboxane A₂ production suppresses the liberation of other vasoconstrictive substances, preventing microcirculatory disturbance and, thereby, contributing to improved graft function after liver transplantation.     

Autopsy case of Lewy body dementia associated with abundant argyrophilic grains]

We report an autopsy case showing neuropathologically abundant Lewy bodies and argyrophilic grains. A Japanese woman without hereditary burden developed parkinsonian gait at the age of 74, following by insomnia, memory disturbance, delirium, resting tremor, rigidity, and retropulsion. About 8 months later, a visual hallucination, concerning small worms, children, and so on, became obvious. About 16 months later, malignant lymphoma was detected. About 17 months later, she died of pneumonia. The total duration of illness was approximately one year and five months. The weight of the brain was 1153 g before fixation. Depigmentation of the substantia nigra and locusceruleus was prominent. Many argyrophilic grains were seen in the temporal lobe (T3, T4), amygdala, and hippocampal CA1. Some ballooned neurons were found in the amygdala. Many Lewy bodies were encountered in the transentorhinal region and cingulated gyrus. A few Lewy bodies were seen in the temporal, frontal, and parietal lobes. In this case, neuropathological examination is compatible for dementia of Lewy bodies and argyrophilic grain dementia, and clinical course is consistent with dementia of Lewy bodies. This report may contribute to the elucidation of the clinicopathological hallmarks of argyrophilic grain dementia and dementia with Lewy bodies.