Inducibility of chromosomal aberrations and cytotoxicity in cultured Chinese hamster cells by cadmium chloride (CdCl2) was investigated under 3 different treatment conditions: (i) 2-h treatment in MEM medium supplemented with 10% fetal bovine serum (MEM + 10% FBS) or (ii) in HEPES-buffered Hanks' solution (HEPES-Hanks), and (iii) continuous treatment for 24 h in MEM + 10% FBS. Two-h treatment with CdCl2 in HEPES-Hanks or continuous treatment for 24 h in MEM + 10% FBS was respectively 2 or 3 times more cytotoxic than 2-h treatment with the metal in MEM + 10% FBS. Continuous treatment for 24 h with a CdCl2 concentration in excess of 5 X 10(-6) M was too toxic to the cells to allow chromosomal analysis, and moreover, only a slight increase in incidence of chromosomal aberrations was observed at a concentration of 5 X 10(-6) M CdCl2. In contrast, a marked and concentration-dependent increase in incidence of chromosomal aberrations was observed after post-treatment culture for 22 h follows 2-h treatment with 1 X 10(-6) M to 5 X 10(-5) M of CdCl2 in both MEM + 10% FBS and HEPES-Hanks. Two-h treatment with cadmium in HEPES-Hanks was approximately 3 times more potent for the induction of chromosomal aberrations than that in MEM + 10% FBS. Types of aberrations induced by CdCl2 mainly consisted of chromatid gaps and breaks, although a few exchanges, dicentrics and fragmentations were observed at high concentrations of cadmium. Increase in incidence of tetraploidy was also observed with a concentration dependency after 2-h treatment with CdCl2. Potency of CdCl2 to induce chromosomal aberrations after 2-h exposure was comparable to that of benzo[a]pyrene activated with S9 at equitoxic concentrations. Two-h treatment with cadmium markedly inhibited incorporation of [3H]thymidine, even at concentrations at which incorporation of [3H]uridine or [3H]leucine was less inhibited. However, the inhibition of [3H]thymidine incorporation by cadmium was reversible and the incorporation restored to the control level during 2-6 h of post-treatment incubation. These findings suggest that restoration of DNA synthesis after cadmium exposure is required for the efficient detection of chromosomal aberrations induced by the metal.

Animals↗

PubMedDate not supplied

Modified distribution of lymphocyte subpopulation in blood and spleen from mice exposed to cadmium.

The effect of cadmium (Cd) on the lymphocyte subpopulation in peripheral blood and spleen was studied in ICR mice given a daily subcutaneous injection of 0.5 and 1.0 mg Cd/kg body weight for 5 days or mice fed with the drinking water containing 3, 30 and 300 ppm Cd for 10 weeks. The reduction of blood B lymphocytes observed in Cd-injected mice was accompanied by the increase of the number of splenic B lymphocytes. On the other hand in Cd-fed mice the reduction of blood T lymphocytes was found and associated with the increase of the number of splenic T lymphocytes. These findings suggest that circulating lymphocytes may redistribute differentially in lymphoid organs responded to the Cd exposure.

Animals↗

PubMedDate not supplied

Surgical treatment of hallux valgus deformity in rheumatoid arthritis: clinical and radiographic evaluation of modified Lapidus technique.

The authors evaluated a modified Lapidus technique for 21 rheumatoid hallux valgus deformities. The technique corrects the deformity by performing arthrodesis of the first tarsometatarsal joint and preservation of the first metatarsophalangeal (MTP) joint. The authors clinically studied patients' subjective improvement of pain and footwear comfort, as well as their satisfaction with the outcome of the surgery. The study also analyzed radiographic changes of the hallux valgus angle (HVA) and two intermetatarsal angles, one between the first and the second (M1/2) and the other between the first and the fifth (M1/5). They were measured before the surgery, 3 weeks after the surgery, and at the last follow-up. Pain relief was great or moderate in 17 feet and footwear comfort was improved in 16 feet. Fifteen patients were satisfied or satisfied with some reservations. The average HVA significantly decreased from 44.1 degrees preoperatively to 10.6 postoperatively and significantly increased again to 29.1 at the last follow-up. The average M1/2 and M1/5 significantly decreased postoperatively (from 13 to 8.3 and from 32.2 to 21.1, respectively), and the reduction of M1/2 remained at the last follow-up (8.7), while M1/5 significantly increased again (28.3). This modified Lapidus technique is a useful method for rheumatoid hallux valgus deformity, which can preserve the first MTP joint.

Aged↗

PubMedDate not supplied

Progression of cellular repopulation and collagen synthesis in fresh-frozen allograft tendons.

The progression of cellular repopulation and collagen synthesis in fresh-frozen rat patellar tendon allografts was investigated by means of indirect immunofluorescence histologic analysis and electron microscopic techniques for 8 weeks after transplantation. In each of 10 procedures, the medial half of the patellar tendon with a tibial bone block was harvested from a Wistar rat and transplanted into a corresponding defect in the medial patellar tendon of a Lewis rat. Actin filaments in the repopulating cells and newly synthesized collagen fibrils in the graft were identified with rhodamine-phalloidin stain and with a polyclonal antibody against type III collagen aminopropeptide. On the first day after transplantation, no specific fluorescence was detected in the graft. One week later, specific labeling for fibrillar-actin (F-actin) and type III collagen aminopropeptide was detected in an area extending from the adjacent granulation tissue into the proximal end of the graft. F-actin and type III collagen aminopropeptide were aligned along the longitudinal axis of the graft and extended from the proximal suture site toward the distal portion. Two weeks after transplantation, fibrillar labeling for F-actin and type III collagen amino-propeptide showed that remodeling had extended to the midportion of the graft. Labeling throughout the entire graft was detected 4 weeks after transplantation. During the entire remodeling process, the repopulated fibroblasts consistently retained their elongated shape and their alignment with the longitudinal axis of the graft. The cells developed well-organized actin bundles at their peripheries, which identified them as having a myofibroblast phenotype. Immunofluorescence detection for type III collagen aminopropeptide also showed consistent alignment parallel to the longitudinal axis of the graft and a fibrillar arrangement. Electron microscopy revealed thinner collagen fibrils in the vicinity of the fibroblasts, which were aligned in the direction of the actin bundles. These results indicate that, during the early remodeling phase, collagen synthesis and deposition in the graft proceeds while the original alignment of the graft matrix is preserved. The close association between the alignment of actin bundles in repopulated "myofibroblastic" cells and that of newly synthesized collagen fibrils along the lines of the graft matrix may represent evidence of force transmission between the actin cytoskeleton and the linking extracellular matrix in vivo.

Journal Article↗

PubMedDate not supplied

Immunohistochemical detection of bcl-2 and p53 proteins and apoptosis in soft tissue sarcoma: their correlations with prognosis.

Information on prognostic factors is essential to establish appropriate therapeutic modalities for soft tissue sarcoma (STS). To evaluate the biological nature and prognostic factors of STS, p53 and bcl-2 expression was immunohistochemically studied on paraffin-embedded sections from 70 patients with STS in the extremities and trunk. In addition, the degree of apoptosis was examined by in situ end-labeling. Histologic diagnoses in these cases were malignant fibrous histiocytoma in 29 cases, liposarcoma in 11, synovial sarcoma in 11, leiomyosarcoma in 5, malignant neurogenic tumor in 5, and others in 9. Tumor cells in 31 of 70 cases (44%) showed positive nuclear staining for p53 protein. There was no correlation between p53 expression and tumor size, histologic grade, argyrophilic nucleolar organizer region (AgNOR) count, cellularity and extent of neerosis. Expression of p53 did not correlate with survival of patients. Tumor cells in 24 of 56 cases (43%) were positive for bcl-2 protein expression. The frequency of bcl-2 expression in the tumor cells showed a direct proportion to tumor size (> or = 10 vs. < 10 cm) but inverse proportion to AgNOR counts and cellularity. The 5-year survival rate in patients with bcl-2-positive tumors (87%) was more favorable than in those with bcl-2-negative tumors (53%; p < 0.05). The frequency of apoptosis in low-grade STS was significantly higher than that in the intermediate and high-grade STS (p < 0.001). Extent of necrosis, a well-known prognostic indicator in STS, was not correlated with the frequency of apoptosis. Multivariate analysis showed that cellularity, bcl-2 and AgNOR counts were independent prognostic factors in patients with STS. The current study revealed that STS with a higher expression of bcl-2 had lower proliferative activity and larger size than those without. Immunohistochemical detection of bcl-2 is useful for predicting prognosis in patients with STS.

Adolescent↗

PubMedDate not supplied

Curved planar reformatted CT angiography: usefulness for the evaluation of aneurysms at the carotid siphon.

BACKGROUND AND PURPOSE: Three-dimensional CT angiography uses the data obtained on a contrast-enhanced CT brain scan to generate 3D images of the intracranial vasculature. We describe the methodology of curved planar reformatting (CPR) for CT angiography and characterize its usefulness in the evaluation of aneurysms at the carotid siphon, comparing it with the shaded surface display technique (SSD). METHODS: Eighty-seven patients with suspected intracranial aneurysms at CT angiography were examined by conventional cerebral angiography, and the patients with aneurysm(s) at the carotid siphon were selected for study. For these patients, the visibility of the neck and fundus of the aneurysms on CT angiograms was compared for those obtained with SSD and those with CPR, and observer reproducibility was evaluated with the kappa statistic. RESULTS: Eighteen patients were confirmed to have an aneurysm at the carotid siphon on conventional angiograms. Seventeen aneurysms were depicted at CT angiography with SSD; 18 aneurysms with CPR. The number of visible aneurysmal necks and fundi was nine and 12, respectively, with SSD; 18 and 18, respectively, with CPR. CONCLUSION: CPR allows better demonstration of the body and neck of an aneurysm at the carotid siphon, which has a tortuous course and is surrounded by complex bony structures. CPR may be a useful adjunct for the evaluation of aneurysms in this region.

Adult↗

PubMedDate not supplied

Aeration time following ethylene oxide sterilization for reusable rigid sterilization containers: concentration of gaseous ethylene oxide in containers.

Because ethylene oxide (EO) gas is toxic to humans, restrictions have been imposed on its use for sterilization, specifying allowable levels of residual EO remaining in sterilized apparatus and materials. However, the aeration time that optimizes the removal of the remaining EO when a rigid sterilizing container is used for a vessel had not been identified. Therefore, polyvinyl chloride, which easily adsorbs EO, was placed in rigid sterilizing containers, and aeration was carried out after 1, 8, 12, 17, and 24 hours. After standard EO sterilization, the EO concentrations remaining in the air in the rigid containers were measured. The results indicate that a period of 17 hours of aeration is appropriate when a rigid sterilizing container is used.

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PubMedDate not supplied

Chronic polyarthritis in inbred C3H/He mice after systemic administration of allogeneic thymocytes.

Chronic polyarthritis was produced in inbred C3H/He mice after intraperitoneal (ip) administration of allogeneic thymocytes of inbred line BALB/c mice. The polyarthritis persisted more than 18 months without additional ip treatment. Histologically, synovial cell hyperplasia, granulation tissue formation, and inflammatory cell infiltration were seen. More than 6 months after the initial administration, range of motion of the affected joints was significantly restricted and the erosive destructions of joint cartilage were found roentgenographically. Thus, this experimentally induced arthritis proved to have many pathologic features in common with human rheumatoid arthritis.

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