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Biomedical subjects

M Jeffery

Publications and source records attributed to M Jeffery.

11 recordsLinked to original sources

Failure of an uncemented non-porous metal-backed prosthesis with augmentation using impacted allograft for acetabular revision 12- to 17-year results.

We have reviewed 29 patients (30 hips) who had undergone revision total hip arthroplasty using a Freeman metal-backed acetabular component and acetabular impaction allografting. The mean follow-up was for 153 years (12 to 17). Five patients (5 hips) died with the prosthesis in situ and four (4 hips) were lost to follow-up. Twelve hips had failed and in the remaining nine there were minor symptoms. The mean time to failure requiring further surgery was nine years. Excluding patients who were lost to follow-up or had died, 72% of the hips were radiologically loose at the last review. The commonest pattern in those requiring revision was failure of the reinforcement ring in adduction with remodelling of the medial wall. Of the nine patients who had not undergone revision, one with bilateral replacements had no current radiographs and only three of the remaining seven replacements had no radiological signs of loosening. The short-term results for this technique have been reported to be satisfactory, but in the long term they are not. The factors associated with failure include the design of the prosthesis, which has been implicated in disappointing long-term results when used in primary arthroplasty, but not with the frequency of failure found in this series. It seems that the reliance on peripheral screw fixation over a bed of allograft without bridging the graft does not provide sufficient stability to allow incorporation of the graft.

Acetabulum↗

Characterization of VX on concrete using ion trap secondary ionization mass spectrometry.

The nerve agent VX (O-ethyl S-2-diisopropylaminoethyl methyl phosphonothiolate) was analyzed on the surface of concrete samples using an ion trap secondary ion mass spectrometer (IT-SIMS). It was found that VX could be detected down to an absolute quantity of 5 ng on a concrete chip, or to a surface coverage of 0.0004 monolayers on crushed concrete. To achieve these levels of detection, the m/z 268-->128 ion fragmentation was measured using MS2, where m/z 268 corresponds to [VX + H]+, and 128 corresponds to a diisopropylvinylammonium isomer, that is formed by the elimination of the phosphonothiolate moiety. Detection at these levels was accomplished by analyzing samples that had been recently exposed to VX, i.e., within an hour. When the VX-exposed concrete samples were aged, the SIMS signature for intact VX had disappeared, which signaled the degradation of the compound on the concrete surface. The VX signature was replaced by ions which are interpreted in terms of VX degradation products, which appear to be somewhat long lived on the concrete surface. These compounds include ethylmethylphosphonic acid (EMPA), diisopropyl taurine (DIPT), diisopropylaminoethanethiol (DESH), bis(diisopropylaminoethane) disulfide [(DES)2], and a particularly tenacious compound that may correspond to diisopropylvinylamine (DIVA), or an isomer thereof. It was found that the thiolamine-derived degradation products DIPT, DESH, and (DES)2 were removed with isopropyl alcohol extraction. However, the DIVA-related degradation product was observed to strongly adhere to the concrete surface for longer than one week. Although quantitation was not possible in this set of experiments, the results clearly show the rapid degradation of VX on concrete, as well as the surface sensitivity of the IT-SIMS for intact VX and its adsorptive degradation products.

Chemical Warfare Agents↗

Analysis of VX on soil particles using ion trap secondary ion mass spectrometry.

The direct detection of the nerve agent VX (methylphosphonothioic acid, S-[2-[bis(1-methylethyl)amino]ethyl] O-ethyl ester) on milligram quantities of soil particles has been achieved using ion trap secondary ion mass spectrometry (IT-SIMS). VX is highly adsorptive toward a wide variety of surfaces; this attribute makes detection using gas-phase approaches difficult but renders the compound very amenable to surface detection. An ion trap mass spectrometer, modified to perform SIMS, was employed in the present study. A primary ion beam (ReO4-) was fired on axis through the ion trap, where it impacted the soil particle samples. [VX + H]+, [VX + H]+ fragment ions, and ions from the chemical background were sputtered into the gas-phase environment of the ion trap, where they were either scanned out or isolated and fragmented (MS2). At a surface concentration of 0.4 monolayer, intact [VX + H]+, and its fragment ions, were readily observable above background. However, at lower concentrations, the secondary ion signal from VX became obscured by ions derived from the chemical background on the surface of the soil particles. MS2 analysis using the ion trap was employed to improve detection of lower concentrations of VX: detection of the 34S isotopic ion of [VX + H]+, present at a surface concentration of approximately 0.002 monolayer, was accomplished. The study afforded the opportunity to investigate the fragmentation chemistry of VX. Semiempirical calculations suggest strongly that the molecule is protonated at the N atom. Deuterium labeling showed that formation of the base peak ion (C2H4)N(i-C3H7)2+ involves transfer of the amino proton to the phosphonothioate moiety prior to, or concurrent with, C-S bond cleavage. To manage the risk associated with working with the compound, the vacuum unit of the IT-SIMS was located in a hood, connected by cables to the externally located electronics and computer.

Chemical Warfare Agents↗

Primary mucinous carcinomas of the skin express TFF1, TFF3, estrogen receptor, and progesterone receptors.

Mucinous carcinoma may present at various sites, including the breast and the gastrointestinal tract. Rarely, such tumors arise within the skin. Comparatively, breast lesions are relatively common and usually associated with a good prognosis. When pure, they are typically estrogen (ER) and progesterone receptor (PR) positive and responsive to tamoxifen. The authors studied 12 mucinous carcinomas of the skin and compared the morphology with that of typical mammary lesions. The authors also evaluated for expression of estrogen receptor, progesterone receptor, and the mucus-associated peptides of the trefoil factor family (TFF), TFF1 (formerly pS2) and TFF2 (formerly SP), using immunohistochemistry. The localization of mRNAs for TFF1, TFF2, and TFF3 (formally ITF) was also studied in a subset of three tumors, using in-situ hybridization with S35 labeled riboprobes. The Grimelius stain was used to look for evidence of neuroendocrine differentiation. Eight resembled type A mucinous carcinomas of the breast, two resembled type B, and one had composite features. The 12th was a papillary neoplasm. The two type B tumors exhibited argyrophilia. All showed strong nuclear staining with the estrogen receptor antibody but a more varied pattern with antibodies to progesterone receptor and TFF1. None labeled for TFF2. The detection of TFF1 in mammalian skin is a novel finding. Cutaneous mucinous carcinoma shows strong similarities to its mammary counterpart, including expression of estrogen receptor, TFF1, and TFF3 mRNA. These observations suggest that some mucinous carcinomas of the skin might respond to antiestrogenic therapies.

Adenocarcinoma, Mucinous↗

The Anagen system for automated fluorometric immunoassay.

We describe a new discrete microprocessor-controlled analyzer, the AN2000, which fully automates fluorometric immunoassays by using a magnetic separation of the solid phase and an alkaline phosphatase label. It can operate in random-access or batch mode with a dwell time typically less than 20 min. The analysis rate is 75 samples per hour and the system can hold refrigerated reagents for as many as 20 different analytes. The substrate and wash buffer are common to all analytes. The system can hold as many as 80 samples at once. The operator can select from the menu-driven operator interface any combination of the available analytes to be run for each sample, using either the touch screen or the keyboard. Results are calculated from a stored calibration curve that is stable for greater than or equal to 1 month. The AN2000 is capable of automating most assay formats because the available timings, volumes, incubations, and wash cycles can be used in any combination.

Alkaline Phosphatase↗

Tuberculosis beliefs among recent Vietnamese refugees in New York State.

OBJECTIVE: To identify newly arrived Vietnamese refugees' beliefs about tuberculosis (TB) and TB education needs. METHODS: In 1994, the New York State Health Department and the Centers for Disease Control and Prevention conducted a survey of 51 newly arrived adult Vietnamese refugees in two New York counties. After being trained in interview methods, two bilingual researchers asked 32 open-ended questions on the causes of TB, TB treatment, and the disease's impact on work and social relationships. RESULTS: Respondents correctly viewed TB as an infectious lung disease with symptoms such as cough, weakness, and weight loss. Hard manual labor, smoking, alcohol consumption, and poor nutrition were believed to be risk factors. Many respondents incorrectly believed that asymptomatic latent infection is not possible and that infection inevitably leads to disease. Nearly all respondents anticipated that having tuberculosis would adversely impact their work, family, and community activities and relationships. CONCLUSIONS: Targeted patient education is needed to address misconceptions about TB among Vietnamese refugees and to help ensure adherence to prescribed treatment regimens.

Adolescent↗