Release of corrosion products by F-75 cobalt base alloy in the rat. I: Acute serum elevations

The release of corrosion products by implants has become a matter of concern. Using a microsphere model, the release of chromium, cobalt, and nickel, secondary to implantation of various surface area exposures of F-75, a cast cobalt-chromium alloy, was studied over a 30 day period in the rat. Dose related elevations were observed in the serum concentration of chromium and cobalt but not of nickel, with the maxima being achieved at 3 days after metal implantation followed by declines in concentration. The chromium elevation, approximately twelvefold for a surface area to body weight (SA/BW) ratio of 300 X is similar to that previously reported in patients receiving total hip replacement arthoplasties . However, the cobalt elevation, twentyfold for a SA/BW ratio of 300 X, has not been previously observed. These serum concentration changes are as yet unexplained, but are probably not due to fibrous capsule maturation or alloy repassivation .     

Gastrulation in the spider Zygiella x-notata involves three distinct phases of cell internalization.

The cell movements of gastrulation were analyzed in embryos of the spider Zygiella x-notata, using time-lapse video, cell tracing, and improved histology. Cells are internalized near the center of the germ disc in three distinct phases. First, cumulus mesenchyme cells ingress and migrate as a group beneath the superficial layer. Second, mass internalization through a blastopore yields a diffusely organized deep layer. Third, superficial cells accumulate at the center of the germ disc to form the caudal bud. The floor is internalized, and the caudal bud moves over the nascent dorsal field to form the caudal lobe. This pattern of gastrulation differs from the canonical pattern described in the historical literature: (1) the cumulus of Z. x-notata is completely formed before any other cells internalize; and (2) the caudal lobe is formed by means of the caudal bud, which is a locus of cell internalization.     

Antibody to hepatitis B surface antigen in haemophiliacs on long-term therapy with Scottish factor VIII.

Thirty-five patients with haemophilia A were studied clinically and serologically between 1971-2 and 1975-6 for evidence of hepatitis B infection. One patient suffered from clinical hepatitis B, and a further eight patients showed antibody responses to hepatitis B surface antigen (HBsAg) consistent with exposure to HBsAg during this period. No evidence for HBsAg exposure was found in 14 patients, while the remaining 12 patients had high titres of antibody to HBsAg at both times and no inferences could be drawn about HBsAg exposure. All patients had received exclusively replacement factor VIII material prepared locally from HBsAg-screened voluntary Scottish blood donations. From the details of the therapy given we calculated that the rate of HBsAg seroconversion in these patients represented about 0.3 HBsAg-containing donations/1000 donations.     

Image analysis derived ploidy and proliferation indices in soft tissue sarcomas: comparison with clinical outcome.

AIMS--To compare prognostic information obtained by image analysis cytometry of paraffin wax embedded soft tissue sarcomas with conventional assessment. METHODS--A CAS 200 image analyser was used to determine DNA content of Feulgen stained cytology preparations and tissue sections and to quantify immunostaining by Ki67 and PC10 antibodies. A mitotic count in 50 high power fields was undertaken and histological grade assigned by the Trojani system. Clinical details including follow up and outcome were obtained by case note review. The Kruskal-Wallis one way analysis test, Spearman rho significance test, Kaplan-Meier method, and log-rank test were applied in statistical analysis. RESULTS--Ploidy status, DNA index, 2.5c exceeding rate, 5c exceeding rate, mitotic count and Trojani grade all correlated significantly with clinical outcome. The relation between Ki67 index and outcome did not reach significance. The PC10 index and outcome were not related. Only 2.5c exceeding rate, 5c exceeding rate, and mitotic count correlated significantly with Trojani grade. CONCLUSIONS--DNA content determination of soft tissue sarcomas by image analysis provides quantifiable information of benefit in prediction of outcome. Larger series are required to determine the independent value of ploidy. In this study quantification of anti-Ki67 and anti-PC10 immunostaining was not of prognostic benefit) by contrast with mitotic count and Trojani grade.     

The role of post-synaptic neurones in the biochemical maturation of presynaptic cholinergic nerve terminals in a mouse sympathetic ganglion

1. The role of post-synaptic adrenergic neurones in the biochemical maturation of presynaptic cholinergic nerve terminals has been investigated in mouse superior cervical ganglion in vivo.2. Selective destruction of ganglion adrenergic neurones chemically, with 6-hydroxydopamine (6-OH-DA), or immunologically, with nerve growth factor antiserum (NGF-antiserum) prevented the normal maturation of choline acetyl transferase (ChAc) activity in presynaptic endings during development. Enzyme activity remained depressed for at least 2 months.3. 6-OH-DA treatment failed to alter ChAc activity in the developing duodenum or diaphragm, organs in which cholinergic fibres do not synapse with adrenergic neurones, suggesting that destruction of post-synaptic neurones per se inhibited presynaptic maturation.4. Similarly, NGF-antiserum, which does not destroy adrenergic neurones in the adult did not alter ChAc activity in adult mouse ganglia.5. These observations suggest that post-synaptic adrenergic neurones regulate the biochemical development of presynaptic cholinergic nerve terminals.     

2-Mercaptoethanol and n-acetylcysteine enhance T cell colony formation in AIDS and ARC.

One contributing factor to the loss of T cells in AIDS may be the impaired ability of T cell precursors to expand, as reflected in a decreased ability of patient cells to form T cell colonies in agar. We and others have noted such a defect in people with AIDS and ARC, and have found that suppressor cells and suppressive plasma contribute to decreased T-CFC formation. We report here that the reducing agents 2-mercaptoethanol (2-ME) and n-acetyl cysteine (NAC) can enhance colony formation in vitro. In part, 2-ME can reverse the defect in T cell colony-forming cells (T-CFC) formation by overcoming the effect of suppressor cells. In a group of 46 AIDS patients, T-CFC formation was initially 42 +/- 8% (mean +/- s.e.) that of control levels. 2-ME caused an increase of 401 +/- 76% in T-CFC formation which was significantly greater than the increase in control T-CFC formation; it also significantly enhanced T-CFC formation by cells from ARC patients. Suppressor cell activity from ten AIDS patients decreased from 58 +/- 21% to 12 +/- 10% when 2-ME was added. Similar data were obtained from 14 ARC patients. NAC, a related antioxidant with low toxicity, also enhanced T-CFC in cells of AIDS and ARC patients. Vitamin C generally did not increase T-CFC formation. The data suggest that certain antioxidants such as 2-ME and NAC may be useful in treatment protocols to enhance T cell numbers in patients with AIDS or ARC.     

Rapid identification and antibiotic susceptibility testing of Salmonella enterica serovar Typhi isolated from blood: implications for therapy

The turnaround time (TAT) for Salmonella enterica serovar Typhi identification and reporting of the antibiotic susceptibility profile was determined for 391 cases of typhoid fever, using the lysis direct plating or lysis centrifugation method of blood culture along with rapid antimicrobial susceptibility testing. The TAT was more rapid (TAT for 90% of the patients [TAT(90)] = 30 h; TAT(100) 相似文献   

Hepatitis B infection in Vietnamese families

The occurrence of hepatitis B infection as measured by sensitive serological tests for HBsAg, HBeAg and hepatitis B-specific antibodies was studied in Vietnamese refugee families. HBsAg was found in 10% of 301 children studied. Totally 74% of all HBsAg-positive children had an HBsAg-positive mother or father and an additional 7% had a positive sibling. The distribution of these cases indicated that the risk of HBs-antigenemia was increased 11-fold for those who had an HBsAg-positive mother compared with all other children. The presence of HBeAg in the HBsAg-positive parents was associated with a threefold higher risk of HBs-antigenemia in children as compared with the presence of anti-HBe. It was thus documented that HBV in this population is spread primarily by intrafamilial routes and prophylactic measures within risk families should largely be able to control the appearance of new HBsAg carriers.