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Biomedical subjects

M M Ferguson

Publications and source records attributed to M M Ferguson.

At least 19 recordsLinked to original sources
PubMed1996

Serum pilocarpine esterase activity and response to oral pilocarpine.

Pilocarpine is used orally to treat xerostomia but patients vary widely in their response and ability to tolerate this drug. To elucidate the potential pharmacokinetic contribution of serum to this variability, the enzymatic hydrolysis of pilocarpine in human serum in vitro was investigated using a stability indicating HPLC assay. The reaction at 37 degrees C follows Michaelis-Menten kinetics (K(m) = 2.78 +/- 0.48 mmol/liter, Vmax = 79 +/- 13 nmol min-1 ml 1; n = 5) and produces pilocarpic acid as the only detectable product. The distribution of pilocarpine esterase activity in a group of healthy young adults at age 21 (n = 163; 87 males, 76 females) was examined by incubating serum samples with pilocarpine (10 mmol/ liter) at 37 degrees C for 60 min. The distribution was positively skewed and ranged from 4 to 132 nmol min-1 ml-1 with a mean value of 55 +/- 23 nmol min-1 ml 1. The means for males and females were not significantly different. Similar measurements in xerostomia patients undergoing treatment with oral pilocarpine showed that those with higher serum esterase activity tolerated pilocarpine well and tended to require higher doses for relief of xerostomia, whereas those with low activity were sensitive to the adverse effects of the drug and were adequately treated with a lower dose. The results suggest that at least some of the variability in response to oral pilocarpine is due to differences in serum pharmacokinetics.

Adult↗
PubMed1996

Superficial copper staining of the teeth in a brass foundry worker.

A 21 year-old man developed green surface staining of the cervical margins of his teeth 10 months after starting work in a brass foundry. During this time he was exposed intermittently to brass fumes which contained approximately 75% copper and 2-5% lead. The staining of his teeth was attributed to the absence of respiratory protection in the knock-out process and was accompanied by a rising blood lead concentration. Staining of the teeth by copper was described early this century but seems to have been neglected in the recent literature and texts on occupational medicine. We suggest that in brass foundry workers it is a warning of failure to control fume or dust exposure with the attendant risk of lead toxicity.

Adult↗
PubMed1996

Enamel erosion related to winemaking.

Enamel erosion is a recognized problem in those ingesting large quantities of fruit juice. While discomfort of the teeth is acknowledged to be a problem for those people tasting wines regularly, the information is anecdotal. A case is presented of a winemaker who has generalized erosion of the teeth, the onset of which is related to his occupation.

Adult↗
PubMed1995

Susceptibility of brook charr, Salvelinus fontinalis to the pathogenic haemoflagellate, Cryptobia salmositica, and the inheritance of innate resistance by progenies of resistant fish.

Eighty-seven of 175 laboratory raised F1 generation brook charr (Salvelinus fontinalis) were resistant to experimental Cryptobia salmositica infection. Susceptibility to the pathogen was not related to age nor to route of infection. Plasma of resistant charr lysed the parasite under in vitro conditions while those of susceptible fish did not. Sperm from 4 susceptible and 4 resistant male charr, from 8 F1 families, were used to fertilize eggs from 2 hatchery raised susceptible charr. Susceptibility of progenies (F2 families) was determined 4 weeks after inoculation of the parasite. All progenies (seven F2 families) of 4 susceptible males were susceptible to experimental infection and their plasma did not lyse the parasite. It was presumed that these susceptible progenies were homozygous recessive (rr), and that the resistant allele was dominant. All progenies (two F2 families) of 1 resistant male (presumed RR) and 2 susceptible females were all resistant to infection and their plasma lysed the parasite. The ratio of resistant to susceptible charr in 6 other F2 families from the other 3 resistant males (presumed Rr) and two susceptible females was about 1:1. The results suggest a single Mendelian locus which determines innate resistance to C. salmositica infection in brook charr and that it is possible to breed Cryptobia-resistant fish.

Alleles↗
PubMed1994

S-100-positive T-cell lymphoproliferative disorder. A case report and review of the literature.

The authors describe a patient with a S-100-positive T-cell lymphoproliferative disorder, characterized by clinically aggressive behavior, with leukemic dissemination and death within 1 year of the onset of symptoms. The neoplastic cells had abundant amphophilic cytoplasm, suggestive of plasmacytoid differentiation, but demonstrated a mature T-cell immunophenotype characteristic of the suppressor-cytotoxic subset. In addition, the cells expressed the S-100 protein within the cytoplasm. Genotypic studies were performed by Southern blot analysis, which demonstrated beta-chain T-cell receptor gene rearrangement, further confirming the T-cell nature of this disorder. This case had features very similar to those of the seven cases previously reported. It has been proposed that the S-100-positive T-cell lymphoproliferative disorder is a distinctive clinicopathologic entity.

Adult↗
PubMed1993

Pilocarpine and other cholinergic drugs in the management of salivary gland dysfunction.

Sialagogues constitute an important component in the management of salivary gland dysfunction. Of the pharmacologic agents available, pilocarpine has been used extensively over the last century. Many clinical trials have documented the efficacy of this alkaloid, with doses that range from 1 to 15 mg normally taken four times a day. There is considerable individual variation in response although it is usually possible, in the presence of sufficient responsive exocrine tissue, to establish a therapeutic regimen that promotes increased salivation without significant side effects.

Anethole Trithione↗
PubMed1993

Effects of dietary gluten elimination in patients with recurrent minor aphthous stomatitis and no detectable gluten enteropathy.

Fifty patients with a history of minor recurrent aphthous stomatitis were entered into a 6-month double-blind controlled trial of a gluten-free diet. After hematologic and biochemical investigations and jejunal biopsy, one half of the group was given a gluten-free diet; the other half served as controls and received a gluten-free diet supplemented by gluten given blind (control diet). Twenty-three patients completed the trial, 11 patients on a gluten-free diet, 12 on the control diet. Four of the 11 on the gluten-free diet and 7 of the 12 on the control diet reported significant benefit in terms of minor recurrent aphthous stomatitis, but there was no statistical difference between the responses. The results fail to support studies that report widespread benefit in aphthae of gluten withdrawal and suggest simply a marked placebo response in the condition.

Adolescent↗
PubMed1992

An unusual case of hemifacial atrophy.

A case of hemifacial atrophy in a 10-year-old boy is described. The presentation in this patient is unusual because the lesion is extremely localized, and the abnormalities of teeth in the affected region are more severe than previously recorded. Alternative diagnoses are considered, and the results of a computed tomographic scan with three-dimensional reformatting are presented.

Child↗
PubMed1992

Familial ogee roots, tooth mobility, oligodontia, and microdontia.

The term ogee is proposed to describe dome or onion-shaped incisor roots as presented in a family study. A case of ogee permanent upper incisor teeth associated with microdontia, oligodontia, and tooth mobility is described. Forty-seven members of the proband's family were examined. The dental abnormalities were found to be of an autosomal dominant pattern of inheritance.

Adolescent↗
PubMed1992

Enzyme heterozygosity and growth in rainbow trout: genetic and physiological explanations.

The possibility of whether the association between enzyme heterozygosity and body size (fork length) is consistent among rainbow trout (Oncorhynchus mykiss) with different degrees of relationship and is affected by fish age was determined. Six-month-old full-sibs and progeny groups from five and 13 parents of each sex do not show the positive associations between multilocus heterozygosity and fork length which are detectable in larger pooled gamete matings (25 females x 25 males). Moreover, the relationship between heterozygosity at single loci and fork length is inconsistent among families. These data suggest that chromosomal segments, marked by the enzyme loci, are responsible for the phenotypic effects (associative overdominance). Fish age affects both the strength and direction of the association between multilocus heterozygosity and fork length; the association is positive in 6-month-old rainbow trout but is weaker, negative, or differs between the sexes in fish at 1 year. Moreover, the strength of the relationship changes over time in repeated measurements on the same fish. A decline in growth of larger and more heterozygous fish, because of precocial sexual maturation, may partially explain the changing relationship between multilocus heterozygosity and fork length. Sexually mature males are significantly more heterozygous than immature males and show significantly reduced recent growth rates as measured by white muscle RNA concentration. However, females, who rarely mature at 1 year, show significantly higher recent growth rates. Thus, heterozygosity is differentially associated with the allocation of energy resources into somatic and reproductive tissue in male and female rainbow trout.

Age Factors↗
PubMed1991

Peanut sensitivity as a cause of burning mouth.

A patient with a history of a burning tongue together with discomfort of the labial and buccal mucosae was given an elimination diet and skin patch tests to determine the allergen in her diet. The patient was identified as being intolerant of an aqueous peanut extract. Three allergens in peanut butter were identified, the one with greatest reactivity being a heat-stable, water-soluble, nonglycosylated protein with a molecular weight in excess of 10 kD. Modification of her diet has resulted in resolution of the oral problem.

Arachis↗
PubMed1991

Facial pain and muscle atrophy secondary to an intracranial tumour.

Orofacial pain rarely arises from a distant site. It is unusual for orofacial pain to be associated with wasting of the facial musculature and diminished sensation. This case report describes a patient who presented with temporomandibular joint pain dysfunction syndrome which was initially successfully managed with splint therapy. She re-presented later with unilateral wasting of the muscles of mastication, facial pain and diminished sensation ipsilaterally. An intracranial meningioma was diagnosed following an extensive series of investigations.

Adult↗
PubMed1991

Comparison of cryosurgery and the carbon dioxide laser in mucosal healing.

Cryosurgery is an established technique for the removal of a range of mucosal lesions. As the portable carbon dioxide laser may provide an alternative form of treatment, the effectiveness of and the healing response following use of the 2 techniques was compared by producing lesions on the lateral border of sheep tongues. Cryosurgery produced more extensive lesions with a marked inflammatory reaction but no differences in the time course of healing were evident. Laser surgery was as effective as cryosurgery in the removal of superficial tissues but caused less swelling and, therefore, may be advantageous in some clinical situations.

Animals↗
PubMed1991

Exposure factors and screen-film combinations in temporomandibular joint radiography.

Exposure factors and screen-film combinations providing optimal quality are identified for transcranial and transpharyngeal temporomandibular joint views, using conventional intra-oral radiographic equipment without grids. Standardized transcranial and transpharyngeal views, using a fixed whole cadaver head, were performed. Ten readily available screen-film combinations, ranging in nominal speed 20-600, were exposed over 40-100 kV. Films were blindly and independently order ranked by three observers on the basis of sharpness and contrast of cortical outline, trabecular detail, and visualization of adjacent bony structures. Preferred screen-film combinations as a function of kV, preferred kV levels for each screen-film combination, and overall ranking irrespective of kV or screen-film combination, were established. Accepting the use of the lowest radiation dose possible for diagnostically useful radiographs but imposing arbitrarily an upper limit of 20 mGy, it was found that exposures between 50 kV and 70 kV gave the optimal result for both techniques. The amount of scattered radiation in the emergent beam differs greatly between the two techniques. The most favoured combinations for the transpharyngeal technique used screens of fine resolution. Min-r/ortho M screen and film with nominal speed 40 at 60 kV gave 8.0 mGy skin dosage at 0.8 seconds exposure; the same combination at 50 kV was the most favoured, but with skin dosage calculated at 16.7 mGy for 3.0 seconds exposure. For the transcranial technique, medium speed screens providing better differentiation of scattered radiation beams and increased speeds were preferred. Most favoured for image quality was the Lanex Fine/T-Mat G combination at 60 kV giving 17.5 mGy skin radiation dose at 1.75 seconds exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthrography↗
PubMed1990

Intra-oral softening of bovine enamel exposed to Lycasin and sucrose.

In previous experiments, the sucrose substitute Lycasin has been shown to possess low acidogenic potential. Intra-oral cariogenicity tests were carried out in humans to explore the enamel softening effects of Lycasin, using sucrose and saline as controls. The results confirmed that Lycasin would be preferred to sucrose as a sweetener for confections and medicines, although some softening of enamel by Lycasin was evident when compared to the saline controls. The magnitude of this enamel change was small and of doubtful clinical significance.

Adult↗