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A L Martin

Publications and source records attributed to A L Martin.

At least 19 recordsLinked to original sources
PubMed2000

Observation of DNA-polymer condensate formation in real time at a molecular level.

Dynamic real time assembly of toroidal and rod-like DNA condensates has been visualised using atomic force microscopy. Imaging has been conducted in an aqueous environment allowing the visualisation of hydrated, pegylated-polymer DNA condensates undergoing dynamic structural movement and conformational change. A major hurdle in the field of gene delivery is cellular transfection and the subsequent transfer of condensed genetic material to the cell nucleus. An increased understanding of the process of DNA condensation will aid the development and optimisation of gene delivery vectors.

Cations↗
PubMed1998

Clinical utility of plasma membrane vesicles expressing recombinant glycophorin A-encoded blood group antigens.

BACKGROUND: Although the genes encoding most of the major blood group determinants are now cloned, recombinant blood group antigens are not commonly used in the clinical laboratory. This study assessed the feasibility of using plasma membrane vesicles expressing recombinant glycophorin A blood group antigens as soluble immunoadsorbants. STUDY DESIGN AND METHODS: Chinese hamster ovary cells were transfected with plasmids containing the cDNA encoding the M- or N-allele of glycophorin A. Plasma membrane vesicles were chemically induced from stable, high-expressing cell lines. Antibodies were assessed for reactivity in hemagglutination-inhibition assays. RESULTS: Eight anti-M antibodies were evaluated. Vesicles expressing the M-allele of glycophorin A neutralized four antibodies (two murine monoclonals; two human sera), while the activity of four human sera was unaffected. Three anti-N reagents were also evaluated (murine monoclonal antibody; rabbit polyclonal antibody; Vicia graminea lectin). All were neutralized by vesicles expressing the N-allele of glycophorin A. There was no detectable neutralization of other clinically significant blood group antibodies. CONCLUSIONS: Plasma membrane vesicles expressing recombinant glycophorin blood group determinants may prove to be useful reagents in the clinical laboratory. However, the partial failure of M antibody recognition requires further study. This general approach could be utilized for any similarly expressed recombinant blood group antigen.

Animals↗
PubMed1998

Testicular seminoma in a patient with a constitutively activating mutation of the luteinizing hormone/chorionic gonadotropin receptor.

A white man who had been diagnosed, 35 years previously at the age of 27 months, to have precocious puberty, was later determined to have familial male-limited precocious puberty (FMPP), on the basis of his family history, increased serum testosterone, prepubertal concentrations of follicle stimulating hormone and luteinizing hormone, and Leydig cell hyperplasia. Recently, this diagnosis was confirmed by molecular genetic analysis that demonstrated the presence of a heterozygous constitutive activating mutation of the luteinizing hormone/chorionic gonadotropin receptor. This dominant gain-of-function Asp578Gly mutation has been shown constitutively to activate the receptor in the absence of the agonist, leading to enhanced synthesis of cAMP and, in turn, to increased, sustained production of testosterone. In 1994, this patient was found to have a testicular seminoma. He represents the first case of a testicular germ cell tumor described in an FMPP patient, raising the possibility of a potentially harmful effect of prolonged increased concentrations of sex hormones, with onset early in life, upon the cellular components of the testes.

Adult↗
PubMed1996

Fluctuations of antibody to ribosomal P proteins correlate with appearance and remission of nephritis in SLE.

Antibodies to ribosomal P proteins are found in widely variable proportions (up to 42%) of patients with SLE depending on the ethnic background of the patient population. Neuropsychiatric disease was first recognized to have increased prevalence with anti-P and more recently liver and renal disease. We describe four patients with SLE and circumscribed episodes of nephritis of relatively short duration. In two patients, antibodies to ribosomal P protein were the only specificity detected at the time of appearance of active nephritis; and in the other two patients, the appearance and disappearance of anti-ribosomal P was simultaneously found with similar fluctuations in anti-dsDNA titers. Anti-ribosomal P antibodies were measured by Western blot and a P peptide-specific ELISA. These data raise the possibility for a pathogenic role for anti-ribosomal P antibodies in lupus nephritis.

Adult↗
PubMed1995

[Comparison of the effects of Rocgel and anti-H2 on the symptomatology of gastroesophageal reflux without esophagitis].

The efficacy of boehmite (Rocgel) and of ranitidine was compared in a randomized, double-blind 4-week trial in patients with symptomatic, endoscopically free macroscopic reflux oesophagitis. Of the 64 patients who completed the study 33 received boehmite and 31 ranitidine. Significant symptomatic improvement occurred in both treatment groups (global clinical score and self evaluation by patients) (p < 0.001). Disappearance of heartburn was 52 per cent (15/29) with boehmite and 53 per cent (16/30) with ranitidine. Disappearance of regurgitation was 48 per cent (10/21) with both treatments. 33% of the patients became totally symptom-free. Our results indicate that boehmite seems to be at least as effective as ranitidine in relieving symptoms. Cost of treatment with boehmite, on the other hand is cheaper than ranitidine. As a safe, locally active mucosal protecting agent and antacid, boehmite is an effective drug for the treatment of reflux oesophagitis without macroscopic lesions.

Adolescent↗
PubMed1994

The nutrition support team: surviving and thriving in an era of reform.

Nutrition support teams today are being buffeted by the winds of change in the health care system. With the emphasis shifting from whether to deliver care to how to do so and to how much that care will cost, nutrition support professionals must stay attuned to their institution's needs--and be prepared to adapt to those needs. This article reviews the types of data collection necessary for teams to remain solid as well as offering tips from experts about ways to harness, and even capitalize on, the changes.

Cost Savings↗
PubMed1991

cDNA cloning, sequence analysis, and chromosomal localization of the gene for human carnitine palmitoyltransferase.

We have cloned and sequenced a cDNA encoding human liver carnitine palmitoyltransferase (CPTase; palmitoyl-CoA:L-carnitine O-palmitoyltransferase, EC 2.3.1.21), an inner mitochondrial membrane enzyme that plays a major role in the fatty acid oxidation pathway. Mixed oligonucleotide primers whose sequences were deduced from one tryptic peptide obtained from purified CPTase were used in a polymerase chain reaction, allowing the amplification of a 0.12-kilobase fragment of human genomic DNA encoding such a peptide. A 60-base-pair (bp) oligonucleotide synthesized on the basis of the sequence from this fragment was used for the screening of a cDNA library from human liver and hybridized to a cDNA insert of 2255 bp. This cDNA contains an open reading frame of 1974 bp that encodes a protein of 658 amino acid residues including 25 residues of an NH2-terminal leader peptide. The assignment of this open reading frame to human liver CPTase is confirmed by matches to seven different amino acid sequences of tryptic peptides derived from pure human CPTase and by the 82.2% homology with the amino acid sequence of rat CPTase. The NH2-terminal region of CPTase contains a leucine-proline motif that is shared by carnitine acetyl- and octanoyltransferases and by choline acetyltransferase. The gene encoding CPTase was assigned to human chromosome 1, region 1q12-1pter, by hybridization of CPTase cDNA with a DNA panel of 19 human-hamster somatic cell hybrids.

Amino Acid Sequence↗
PubMed1991

Enzyme immunoassay for identification of Vibrio vulnificus in seawater, sediment, and oysters.

Historically, methods used to identify Vibrio vulnificus in environmental samples have been inadequate because isolation and identification procedures are time-consuming and fail to separate V. vulnificus from other bacterial species. We describe an enzyme immunoassay (EIA) and culture techniques which identified V. vulnificus in seawater, sediment, and oysters. The EIA used monoclonal antibody FRBT37 to a species-specific epitope of V. vulnificus. No cross-reactions were observed among 72 non-V. vulnificus strains comprising 34 species and 15 genera. In field trials, the EIA identified correctly 99.7% of 348 biochemically confirmed V. vulnificus isolates. The epitope corresponding to FRBT37 was found in cells lysed by Triton X-100, deionized H2O, and ultrasonication but was not found in culture supernatants, indicating that its location was intracellular. In addition, electron micrographs of V. vulnificus labeled with FRBT37-biotin-avidin-gold showed that epitope FRBT37 reacted with fragments of lysed cells but not whole cells. FRBT37 was expressed when V. vulnificus was cultured in different growth media. The minimum level of detection of the EIA was approximately 2,000 V. vulnificus cells per EIA well. Epitope FRBT37 was labile at 70 degrees C for 30 min. Immunoblot and EIA plate formats reduced assay time and facilitated handling large numbers of test samples.

Animals↗
PubMed1991

Plague?

Explore the source record for details and available documents.

History, Ancient↗
PubMed1990

Enzyme linked immunosorbent assay for detecting adenoviruses in stool specimens: comparison with electron microscopy and isolation.

A commercial enzyme linked immunosorbent assay (ELISA) for detection of adenoviruses in stool samples was compared with the use of electron microscopy and isolation in Graham 293 cells. Although specific, the ELISA was less sensitive than both electron microscopy and isolation. The ELISA had an overall sensitivity of 78% and a specificity of 100%. The sensitivity was related to the amount of virus particles present in the stool sample, increasing to 90% with about 10(7) viral particles/ml of stool. The ELISA was easy to perform, requiring no instrumentation, and is a useful first line test for detection of adenoviruses in stool samples, especially in laboratories without access to an electron microscope. Wider use of ELISAs should help in evaluating the role of adenoviruses in viral gastroenteritis.

Adenoviruses, Human↗
PubMed1990

Different glycosylation of human prolactin in cystic fibrosis patients.

1. The elevated (Cl) of sweat from cystic fibrosis (CF) skin reverted to normal after the skin had been grafted onto immunoincompetent, congenitally athymic mice [N'NIH(S)-NU]. 2. The sweat (Cl) of CF skin grafts unlike that from normal skin did not increase when the host mice were injected with antibodies to human prolactin (hPRL). 3. One explanation for the above observations postulated a structurally modified PRL in CF patients. Circulating PRL in CF appears to contain a larger amount of glycosylated variants than that of healthy individuals.

Adolescent↗
PubMed1987

An assessment of the sensitivity of three methods for the detection of rotavirus.

A comparison was made of the sensitivity of a current commercial ELISA for detecting rotavirus in faecal specimens with the more complex, technically demanding systems of electron microscopy and polyacrylamide gel electrophoresis. Even after modification, the ELISA failed to detect 22% of specimens with particles identifiable by electron microscopy. Polyacrylamide gel electrophoresis failed to identify 2 out of 50 specimens with particles present but did distinguish 2 group C rotaviruses.

Diarrhea↗
PubMed1986

Testosterone treatment of constitutional delay in growth and development: effect of dose on predicted versus definitive height.

The outcome of treatment in 3 groups of boys with constitutional delay in growth and development given monthly intramuscular injections of testosterone enanthate 200 mg (22 subjects) 100 mg (10 subjects) and 50 mg (12 subjects) was compared with the outcome in a control group (14 subjects) without treatment. The 4 groups were similar in chronological age, height, height age, bone age, height age/bone age ratio, pubertal development and had similar predicted adult heights. All treated subjects achieved an excellent growth response with growth velocities reflecting androgen dose. Bone age advanced commensurate with height age in all the treated groups and delta height age/delta bone age ratios at the end of therapy did not differ significantly. Nor was there a significant difference in the height prediction by the RWT method before and at the end of treatment. However, the year following treatment, growth velocities reversed so that those who received the largest steroid dose and had grown the fastest, decelerated the most and eventually ended up significantly shorter than their predicted adult height. In contrast the control group and those treated with smaller doses of testosterone achieved their predicted heights. The present study confirms that large doses of androgens compromise adult height and are contraindicated in the treatment of constitutional delay in growth and development. Testosterone enanthate 50 mg/mo did not affect predicted adult height adversely, but to the contrary, permitted it to be fully realised. The data caution against drawing conclusions based on changes observed during androgen therapy in the absence of extended follow-up.

Adolescent↗
PubMed1981

Reliability of percutaneous needle aspiration biopsy for diagnosis of bronchogenic carcinoma.

Aspiration biopsy is a widely accepted diagnostic modality for intrathoracic lesions. Between August 1978 and July 1980, percutaneous needle aspiration biopsy was utilized as a means to diagnose intrathoracic lesions in 82 patients. Cytologic diagnosis was obtained in 81 of 82 patients, 60 with a diagnosis of malignant lesions and 21 of nonmalignant lesions. Forty-four patients (53.7%) were treated surgically and 38 patients (46.3%) were treated conservatively, including radiotherapy and/or chemotherapy. Of the 44 patients who came to surgery, 35 had a malignant cytologic diagnosis. Surgery was performed in 11 patients with an initial benign cytologic diagnosis--there were 4 benign tumors, 4 inflammatory lesions and 3 false-negative cases. Of the 3 negatives, two patients had been biopsied on a second occasion with a malignant cytologic diagnosis. Of the 38 patients treated conservatively (malignant 27, benign 10, insufficient specimen 1) only one patient initially considered benign was later diagnosed with unresectable malignancy. The full collaboration of the radiologist and cytologist at the time of the biopsy has contributed to 94% sensitivity, 100% specificity, and 100% predictive valve for aspiration biopsy of intrathoracic lesions.

Adolescent↗