Performance of Wheel-Typed Vehicle with Crawlers in Between Front and Rear Wheels on Soft Ground

A wheeled vehicle with crawlers between the front and back wheels has been developed in order to move swiftly over both soft ground and pavement. Vehicle trafficability on dry sand was evaluated in experiments, which clarified that its trafficability was greater than for wheels on dry sand alone.

Kinematics of Wheel-Type Tracked Vehicle with Crawlers in Between the Front and Rear Wheels

Tracked vehicles are generally trucked to the field because they cannot move on the pavement. This operation is very slow and inefficient. To solve the problem, it is necessary to develop tracked vehicles that can move swiftly on both soft ground and pavement. Wheel-type tracked vehicles with crawlers in between the front and rear wheels can move swiftly using only the wheels on pavement and both wheels and crawlers on soft ground. However, such vehicles cannot turn on both wheels and crawlers. In this study, this steering constraint condition of the vehicle was analyzed with inverse kinematics. Using the obtained optimal conditions, numerical simulations and experiments were carried out. The vehicle’s turning performance was also shown to improve.

Added value of automated clinical proton MR spectroscopy of the brain

OBJECTIVE

A trial was conducted to establish the added diagnostic value of an automated proton MR spectroscopy (MRS) examination (PROBE).

MATERIALS AND METHODS

The PROBE and MRS were compared for metabolite ratios of normal controls and 21 patients. In addition, PROBE was performed in either the occipital cortex (gray matter) or the parietal cortex (white matter) or, more rarely, within the confines of a focal lesion identified on MRI, using a GE Signa 1.5 T whole-body scanner, in 112 patients undergoing routine brain MRI. The trial was conducted in three different MR centers to establish percentage of positive findings with MRI vs. MRI plus MRS.

RESULTS

Cerebral metabolite ratios (N-acetylaspartate/creatine, choline/creatine, myo-inositol/creatine) obtained by PROBE and MRS were similar. Metabolite profiles in dementia, head trauma, herpes encephalitis, hepatic and hypoxic encephalopathy, stroke, and tumor were identified using PROBE. The PROBE technique increased the number of positive findings ("added value") achieved by MRI; the added value was 28, 21, and 93% for the three trial sites.

CONCLUSION

With only minor variations, PROBE reproduces the cerebral metabolite patterns obtained with MRS. It significantly increases the diagnostic yield of routine neuroimaging and might be incorporated as a standard sequence in a cost-effective manner.

[23Na-NMR measurements of the sodium concentration in guinea pig erythrocytes: the effects of cardiac glycoside and asebotoxin III]

Intra- and extracellular sodium in guinea pig erythrocytes was evaluated with sodium-23 nuclear magnetic resonance (23Na-NMR) by the use of a shift reagent, Dy(TTHA)3- or Dy(PPPi)2(7-). The test medium contained erythrocytes at 40% hematocrit level and NMR buffer (145 mM NaCl, 10 mM Dy(TTHA)3-, 10% D2O, adjusted to pH 7.4 with tris, at 35 degrees C). NMR spectra were obtained with a JEOL GSX 400 spectrometer operating at the Fourier transform mode of resonance signals, and the accumulated signals provoked by radio-frequency pulses of 90 degrees were recorded on paper. Quantitative Na determination was performed by measuring the area under the peak of intracellular sodium (Nai) NMR signals. Ouabain (Oua: 0.3 mM) and asebotoxin-III (ATX-III: 0.3 mM) produced an increase in Nai-NMR signals to a level of 188.1% and 138.1% of the control, respectively. Combined use of Oua (0.15 mM) and ATX-III (0.15 mM) produced an elevation of Nai concentration to a high level of 219.0% of the control in a superadditive manner. Mechanisms of the Nai elevation with Oua and ATX-III can be interpreted by assuming two different actions: ATX-III increases net Na(+)-influx via Na+ channels, while Oua inhibits the pumping out of Na+ from the cell.

Malignant tumors during the first 2 decades of life in the offspring of atomic bomb survivors

The risk of cancer (incidence) prior to age 20 years has been determined for children born to atomic bomb survivors and to a suitable comparison group. Tumor ascertainment was through death certificates and the tumor registries maintained in Hiroshima and Nagasaki. The rationale for the study stemmed from the evidence that a significant proportion of such childhood tumors as retinoblastoma and Wilms tumor arise on the basis of a mutant gene inherited from one parent plus a second somatic cell mutation involving the allele of this gene. Gonadal radiation doses were calculated by the recently established DS86 system, supplemented by an ad hoc system for those children for one or both of whose parents a DS86 dose could not be computed but for whom an ad hoc dose could be developed on the basis of the available information. The total data set consisted of (1) a cohort of 31,150 live-born children one or both of whose parents received greater than 0.01 Sv of radiation at the time of the atomic bombings (average conjoint gonad exposure 0.43 Sv) and (2) two suitable comparison groups totaling 41,066 children. Altogether, 43 malignant tumors were ascertained in the children of exposed parents, and 49 malignant tumors were ascertained in the two control groups. A multiple linear regression analysis revealed no increase in malignancy in the children of exposed parents. However, examination of the data suggested that only 3.0-5.0% of the tumors of childhood that were observed in the comparison groups are associated with an inherited genetic predisposition that would be expected to exhibit an altered frequency if the parental mutation rate were increased. There is thus far no confirmation of the positive findings that Nomura found in a mouse system.

Tumorigenicity study of sodium erythorbate administered orally to mice

Sodium erythorbate (SE) was administered at concentrations of 0, 1.25, or 2.5% (maximum tolerated dose, MTD) in the drinking-water to groups of 50 male B6C3F1 mice respectively. Female groups, each consisting of 50 mice, received SE in the drinking-water at concentrations of 0, 2.5 or 5% (MTD). Treatment continued for 96 wks and the experiment was terminated during wk 110. Tumors were observed at various sites including the liver, hematopoietic system, lung and soft tissue. However, at any of the sites, the tumor incidence, the time to death with tumors or the histological distribution of tumors did not differ significantly from those in the untreated control group. Thus, the present study did not demonstrate a tumorigenic effect of SE on B6C3F1 mice by means of oral administration.

Early cancer and related lesions in the bronchial epithelium in former workers of mustard gas factory

The bronchial epithelium in stepwise transverse sections was examined histologically in 66 male autopsy cases, composed of the groups of 19 mustard gas (MG) ex-workers with lung cancer, 17 MG ex-workers with non-lung cancer, 10 non-MG lung cancer cases, and 20 non-MG non-lung cancer cases. Foci of moderate or severe atypical cellular lesion or dysplasia, or of carcinoma in situ (CIS) in total slides of each group, were counted as 146 in 3,485, 72 in 2,226, 70 in 3,797, and 18 in 4,611, respectively. The relative frequency of moderate or severe dysplasia and CIS in MG exposed non-lung cancer cases resembled that found in lung cancer cases of both MG and non-MG exposed. Seven CIS lesions were detected from among all MG-exposed cases and one CIS was found in a non-MG lung cancer case. Six out of eight CIS examples were adjoined by dysplasia. A multi-variate analysis revealed a significant correlation between the incidence of atypical lesions and MG exposure, though the incidence of atypical lesions was also influenced significantly by age, smoking, and chronic bronchitis. The incidence of atypical lesions was significantly higher in cases of squamous cell lung cancer than those of other histological types, particularly small cell cancer.

Tumorigenicity study of butyl and isobutyl p-hydroxybenzoates administered orally to mice

Butyl p-hydroxybenzoate (n-BHB) and isobutyl p-hydroxybenzoate (i-BHB) were administered orally to ICR/Jcl mice at concentrations of 0.6 (maximum tolerated dose), 0.3 or 0.15% in the diet for up to 102 wk. Tumours were observed at various sites including the haematopoietic system, the lung and the soft tissue. However, at none of the sites did the tumour incidence or the time to death with tumours differ significantly from that in the untreated control group.

Insulin resistance in an infant with leprechaunism

A Japanese female infant with typical features of leprechaunism exhibited glucose intolerance despite marked hyperinsulinemia, indicating insulin resistance. Circulating insulin appeared to be chemically and biologically normal. There was no evidence of antagonism of insulin action or circulating antibodies to insulin or insulin receptors. Insulin receptor assay of her erythrocytes showed very low affinity despite a six-fold increase in the number of receptors as compared with those of normal adult controls. Our studies indicate that insulin resistance in this patient appears to be due to a qualitative abnormality of insulin receptors or to a postreceptor defect.

Findings of myoepithelial cells in human breast cancer. Ultrastructural and immunohistochemical study by means of anti-myosin antibody

Detailed light and electron microscopic, and immunohistochemical observations were made on the distribution and morphological characteristics of myoepithelial cells in the 53 cases of breast cancer. In non-invasive carcinoma, myoepithelial cells in the normal duct were found to be remaining at the outer margin of the cancer nests, but neoplastic myoepithelial cells were not detected in the carcinoma tissue. In invasive carcinoma, a small number of fluorescence-weakly-positive cells could be observed in more than 50% of medullary-tubular carcinoma, in all cases of papillary-tubular carcinoma, and two of three cases of invasive lobular carcinoma. Almost all of these cells were ultrastructurally intermediate cells which have the morphological characteristics of both epithelial cell and myoepithelial cell. Fluorescence-positive cells were observed in all cases of scirrhous carcinoma. Moreover, these cells showed a stronger fluorescence than that of other types of carcinoma and were ultrastructurally more similar to normal myoepithelial cell. The tumor cells having myoepithelial characteristics in invasive carcinoma showed a stronger tendency for arranging at the margin of carcinoma nests in contact with the stroma. The results of the present study indicate that in invasive carcinoma of the breast, neoplastic myoepithelial cells could be demonstrated together with ductal epithelial cells and as to its histogenesis, there is a possibility that breast cancer develops from common stem cells which have the ability of differentiating into both epithelial and myoepithelial cell because of the presence of intermediate cells.

Gray scale ultrasonography of a traumatic biliary cyst

Traumatic hepatic biliary cysts, which occur when there is leakage after traumatic disruption of the biliary system, can be readily detected with hepatic sonography. Differentiation from other hepatic fluid collections can be made by percutaneous thin needle aspiration. Aspiration may have possible utility as a therapeutic modality. A case is presented in which Gray scale ultrasonography revealed a biliary cyst which was drained operatively and resolved.