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Biomedical subjects

M E Wilson

Publications and source records attributed to M E Wilson.

At least 271 records · Page 15Linked to original sources
PubMed1991

Rapid preparation and quality control method for technetium-99m-2-methoxy isobutyl isonitrile (technetium-99m-sestamibi).

Technetium-99m-2-methoxy isobutyl isonitrile (99mTc-sestamibi) is a radiopharmaceutical that can be useful in the evaluation of patients with acute myocardial infarction. The current method for preparation requires a lengthy boiling water bath procedure and the recommended quality control procedure is cumbersome and time-consuming. Using a microwave oven, the heating time necessary to provide a labeling efficiency (averaging 97% for sestamibi-labeled with maximum allowable 99mTc activity and volume has been reduced to 10 sec. A new mini-paper chromatography (MPC) system has been developed to analyze the radiochemical purity of 99mTc-sestamibi involving a 1:1 chloroform/tetrahydrofuran developing solvent. The recommended thin-layer chromatography (TLC) system involving the use of an AI2O3-coated plate requires an average time for drying and development of 34.8 +/- 1.6 min (n = 58) to complete, whereas the new MPC system has an average developing time of 2.3 +/- 0.1 min (n = 26). For radiochemical purity values ranging from 71-99% (n = 31), the MPC and TLC methods correlated closely (r = 0.99) with a regression line of MPC% = 1.05 TLC%--5.75. The combined use of the microwave oven heating method and our quick quality control system will facilitate the rapid, emergency use of 99mTc-sestamibi and eliminate the need for advance preparation of multiple kits each day.

Chromatography, Paper↗
PubMed1991

Congenital ptosis. Long-term results of treatment using lyophilized fascia lata for frontalis suspensions.

This report extends a prospective collaborative study published in 1982 of congenital ptosis repair using lyophilized human fascia lata to investigate the permanency of banked human fascia lata. Fifty-six patients are described with a mean postoperative follow-up of 7.2 years and a median follow-up of 8.3 years. Significant recurrence of ptosis was documented in 24 of 56 (43%) patients. New failures continue to be recognized even in the eighth postoperative year. Life table and survival analysis predicts a success rate from frontalis suspension surgery using lyophilized human fascia lata of 90% at 2 to 3 years, 70% at 5 to 6 years, and 50% at 8 to 9 years.

Blepharoptosis↗
PubMed1990

The major Leishmania donovani chagasi surface glycoprotein in tunicamycin-resistant promastigotes.

Two populations of Leishmania donovani chagasi promastigotes resistant to the lethal effects of tunicamycin (TM), an inhibitor of N-linked glycosylation, were raised. These parasites exhibited altered patterns of glycosylation when compared to wild-type controls. In particular the major surface glycoprotein gp63 was present in membranes of one population of TM-resistant promastigotes (population 1) primarily in a deglycosylated form, which migrated at a lower Mr than wild-type gp63. The deglycosylated protein was proteolytically inactive on substrate-containing gels, in contrast to glycosylated gp63. Assays of promastigote attachment to human macrophages revealed that, despite a proposed role for gp63 protease activity in binding to macrophage receptors, population 1 TM-resistant promastigotes appeared to attach to the CR3 but not to the mannose-fucose receptor. Control promastigotes bound to both receptors. In contrast, a second population of TM-resistant promastigotes (population 2) did not produce gp63 that could be detected on immunoblots, either in a glycosylated or deglycosylated form. The latter TM-resistant promastigotes bound to neither CR3 nor the mannose-fucose receptor, suggesting that expression of gp63 might be important for promastigotes to bind to CR3. LPG was present in immunoblots of both TM-resistant and control populations suggesting this molecule might not account for the differences in attachment. Surprisingly both TM-resistant promastigote populations contained gp63 mRNA by Northern analysis in apparently equal amounts. We conclude that N-glycosylation is probably necessary for the protease function of gp63, but that neither N-glycosylation nor protease activity of gp63 is necessary for L. donovani chagasi promastigotes to bind to CR3. Furthermore the expression of gp63 protein by TM-resistant promastigotes is dependent upon postranscriptional events.

Animals↗
PubMed1990

Rhabdomyosarcoma of the ciliary body.

Rhabdomyosarcoma is the most common malignant orbital tumor of childhood. It has twice been reported to arise within the globe from the iris. In addition, teratoid medulloepithelioma, a tumor arising from the ciliary epithelium, can contain a rhabdomyoblastic component, often in combination with other heteroplastic elements. The authors report what may be the first recorded case of an embryonal rhabdomyosarcoma of the ciliary body, possibly representing a one-sided differentiation of a malignant teratoid medulloepithelioma.

Actins↗
PubMed1990

Modification by sialic acid of Neisseria gonorrhoeae lipooligosaccharide epitope expression in human urethral exudates: an immunoelectron microscopic analysis.

Expression of lipooligosaccharide (LOS) antigenic determinants during human gonococcal infection was studied in secretions from seven men with gonococcal urethritis. Five monoclonal antibodies with distinct gonococcal LOS specificities and an H.8 lipoprotein monoclonal antibody were used in combination with immunogold electron microscopic analysis. The LOS epitope defined by antibody 6B7 was present on all seven strains in secretions and after in vitro growth. Gonococci from six of seven patients, when grown in vitro, expressed the 6B4 LOS epitope. The 6B4 epitope is a Gal beta 1-4-GlcNAc residue, which is immunochemically similar to the precursor of the human erythrocyte i antigen. This epitope was found unmodified on gonococcal LOS in urethral secretions from two patients. The unmodified epitope could not be demonstrated on organisms in five secretions. Neuraminidase digestion exposed the 6B4 epitope on organisms in these secretions and increased the 6B4 epitope density in the two secretions, which contained the unmodified epitope. These studies indicate that in vivo modification by sialylation of gonococcal LOS Gal beta 1-4-GlcNAc residue occurs during human infection.

Antibodies, Monoclonal↗
PubMed1990

Outer membrane protein and lipopolysaccharide heterogeneity among Eikenella corrodens isolates.

Outer membrane protein (OMP) and lipopolysaccharide (LPS) phenotypic diversity among 27 oral and extraoral strains of Eikenella corrodens was assessed by SDS-PAGE. Each strain exhibited one to three major protein bands in the 35- to 41.5-kDa range and one or two protein bands of lesser density in the 24.5- to 28-kDa range. Eleven OMP patterns were distinguished among the strains. While oral strains obtained from periodontally healthy and diseased subjects exhibited diverse OMP patterns, five of six strains from extraoral sites of infection expressed an identical OMP pattern. Comparison of the electrophoretic mobilities of LPS from these same strains revealed that E. corrodens LPS consists primarily of low apparent molecular mass forms. Sixteen different LPS phenotypes were differentiated among the strains, with no apparent correlation between LPS phenotype and clinical setting. Strains expressing the same OMP pattern frequently expressed variable LPS phenotypes and vice versa. Analysis of OMP or LPS pattern by SDS-PAGE may be useful in taxonomic and epidemiologic studies of E. corrodens. Additional studies assessing the potential influence of OMP composition on invasiveness of this organism appear warranted.

Bacterial Outer Membrane Proteins↗
PubMed1990

The widened mediastinum. Diagnostic and therapeutic priorities.

Little attention has been given to the sequential assessment and management of a cohort of patients with potential aortic disruption manifested by a widened mediastinum. These patients often require diagnostic peritoneal lavage (DPL), cranial computed tomography (CCT) scan, thoracic aortography, and multiple operations. We surveyed 408 patients with a widened mediastinum who underwent aortography from 1981 to 1989 to determine priorities of management. Multisystem injuries were common with 278 (68%) and 72 (18%) of patients requiring DPL and celiotomy, respectively. Central nervous system (CNS) injury occurred in 276 (68%) patients, and orthopedic injuries were present in 162 (40%). There were 35 thoracic aortic injuries and 17 branch injuries with 15 deaths (11 aortic, 4 branch). Mortality primarily was attributed to hemorrhage, neurologic injuries, and multisystem organ failure. We evaluated the sequence of diagnostic and therapeutic interventions to determine possible sequence errors and 98% of patients had no errors identified. Based on this experience, we have formulated a management protocol for evaluation of patients with multiple injuries and a widened mediastinum.

Adult↗
PubMed1990

Family dynamics during pregnancy.

Pregnancy as a transition in family life is perceived as a crisis by many families. Sociodemographic characteristics of families during pregnancy can serve as important sources of information to nurses in drawing out family strengths and providing assistance during this crisis. Family dynamics were measured in 160 women in the third trimester of pregnancy. Half were in their first pregnancy and half were in their second pregnancy. The research question addressed the relationship between family dynamics and several sociodemographic characteristics. Statistically significant relationships were found between the sociodemographic variables of marital and social status, and several dimensions of family dynamics. Families in which couples were married and who enjoyed a higher social status had more positive family dynamics in the dimensions of individuation, stability, flexibility, mutuality and communication. Race, maternal age and parity were not related to level of family dynamics. Strengths in families who have more positive dynamics may be explained by availability of resources, their expertise in using the system, societal approval of marriage and internal family support from the husband. It is essential for nursing care to include systematic family assessment, socialization in effectively using the health care system and individualized family guidance.

Adolescent↗
PubMed1990

DNA homologies shared among E. corrodens isolates and other corroding bacilli from the oral cavity.

In a previous microbiological study of Eikenella corrodens, we noted the presence of E. corrodens strains with variability in colony morphology, as well as other corroding bacilli phenotypically similar to E. corrodens but which were unidentifiable on the basis of biochemical reactions. This raised questions as to whether E. corrodens constitutes a genetically heterogeneous group of organisms, and whether the unidentified corroding bacilli represent atypical E. corrodens or genetically unrelated organisms. In the present study, the genetic relationship among 14 E. corrodens isolates and 6 unidentified corroding bacilli was examined. DNA base compositions were determined from the melting temperatures of DNA samples. DNA homologies among E. corrodens and corroding bacilli were determined by DNA hybridization in solution using S1 nuclease. The % G + C content of E. corrodens strains varied from 56 to 58%, and from 56 to 60% for unidentified corroding bacilli. The DNA homologies among 12 E. corrodens isolates and 2 reference strains varied from 57 to 97%. Although these E. corrodens isolates exhibited variabilities in colony morphology and biochemical profile, no subspecies was identified. The unidentified corroding bacilli shared less than 33% homology with either of the E. corrodens reference strains. These corroding bacilli were further divided into 3 species on the basis of DNA hybridization studies using radiolabeled DNA from 2 representative corroding bacilli. One of the unidentified corroding bacilli appears to be a component of the normal flora in the human oral cavity. Our results indicate that E. corrodens is a genetically homogeneous species containing no recognizable subspecies.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria↗
PubMed1990

Restriction endonuclease analysis of Eikenella corrodens.

Eikenella corrodens is a gram-negative facultative bacillus commonly found in the oral cavity. Although the role of E. corrodens in periodonititis is not clear, its isolation from extraoral infections attests to its pathogenic potential. Previous studies suggested that this species is phenotypically diverse. In the present study, we used restriction endonuclease analysis (REA) to assess the genetic diversity of this species and to explore the applicability of REA in studying the transmission of E. corrodens. Two groups of E. corrodens isolates were used in this study. Group 1 included 47 epidemiologically independent isolates recovered from dental plaques in periodontally healthy subjects and periodontitis patients and from extraoral infections in different geographic areas. Group 2 E. corrodens included 40 isolates recovered from two periodontitis patients and two periodontally healthy subjects. The results indicated that E. corrodens is genetically heterogeneous, as determined by REA. The majority of the group 1 E. corrodens isolates exhibited strain-specific restriction patterns. Forty restriction patterns were distinguishable among the 47 isolates. Analyses of group 2 isolates revealed that three of four subjects harbored more than one clonal type of E. corrodens. In one instance, a periodontitis patient was found to be colonized by six different clones. Furthermore, two different clonal types of E. corrodens were recovered from a single periodontal pocket in this patient. The results indicated that REA may be a useful tool in the epidemiologic investigation of E. corrodens infections.

Bacteroides↗
PubMed1990

So many worlds.

Explore the source record for details and available documents.

Audiology↗
PubMed1989

Expression of the major surface glycoprotein of Leishmania donovani chagasi in virulent and attenuated promastigotes.

Using both hamster and mouse models of infection, we documented that the virulence of Leishmania donovani chagasi promastigotes decreases over time, when parasites are maintained in long term culture after isolation from an infected animal. Concomitant with this loss of virulence is a marked decrease in amount of the major promastigote surface glycoprotein, gp63, present in promastigotes. The latter was shown by a decrease in binding of polyclonal anti-gp63 serum to attenuated (cultivated long term) as compared to virulent (recently isolated) promastigotes, using immunofluorescence and Western blot assays. Binding of Con A to promastigote glycoproteins, separated by SDS-PAGE, documented a similar decrease. An alteration in the mechanism of promastigote attachment to macrophages was also noted: purified gp63 inhibited attachment of virulent promastigotes to human monocyte-derived macrophages, but it did not affect the attachment of attenuated promastigotes. Northern blot analysis showed that, despite marked differences in the amount of gp63 protein, the quantity of gp63 RNA was comparable in attenuated and virulent promastigotes. However, virulent promastigotes contained two major gp63 RNA species of 3.0 and 2.7 kb, whereas attenuated promastigotes had one predominant gp63 RNA of 2.7 kb and only minor amounts of 3.0 kb RNA. Thus, the decrease in gp63 expression in attenuated, contrasted to virulent, promastigotes is associated with qualitative, but not quantitative, differences in the gp63 messenger RNA.

Animals↗
PubMed1989

Radiologic findings in hemorrhagic colitis due to Escherichia coli O157:H7.

Hemorrhagic colitis due to Escherichia coli O157:H7 is a distinct clinical entity characterized by abdominal pain, watery diarrhea progressing to bloody diarrhea, and little or no fever. It has been reported to have a mortality as high as 31%. This form of colitis is not described in the radiologic literature. This paper describes the radiographic findings, and stresses the need for radiologists to be familiar with the disease in order to assist in early diagnosis. Key clinical and epidemiological features are reviewed.

Adult↗
PubMed1989

Effects of estrogen and prostaglandin on progesterone-delayed farrowing.

Effects of estradiol benzoate and prostaglandin F(2alpha) (PGF(2alpha)) on concentrations of progesterone and estrogen in serum and the percentage of live births were determined in 21 gilts treated with exogenous progesterone in late gestation. All gilts received progesterone (25mg s.c. four times daily) from Days 108 through 113 of gestation. Gilts receiving no other treatments (controls) had elevated levels of progesterone through 1800 h on Day 114 (29.2 +/- 11.4 ng/ml) and farrowed at 115.6 +/- 0.3 d of gestation with a relatively low percentage of live births (66.8 +/- 17.3). Gilts treated with PGF(2alpha) administered at 0600 h on Day 114 had less (P<0.01) progesterone by 1800 h (7.0 +/- 1.3 ng/ml) relative to that of the controls, but they had similar gestation lengths (115.5 +/- 0.3) and percentages of live births (50.0 +/- 16.2). Administration of estradiol benzoate (10 mg) to gilts at 0600 h on Day 114 did not reduce progesterone on Day 114 or the gestation length relative to that of the control gilts, but it did increase (P<0.05) the percentage of live births (100%).

Journal Article↗