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Biomedical subjects

M E Martin

Publications and source records attributed to M E Martin.

At least 91 records · Page 5Linked to original sources
PubMed1986

Sunflower oil is not allergenic to sunflower seed-sensitive patients.

The allergenicity of edible oils derived from sunflower seeds was investigated in two patients with anaphylactic sensitivity to sunflower seeds. Specific IgE-mediated hypersensitivity to sunflower seed was demonstrated by history, prick skin tests, positive passive transfer skin test, and RAST. Specific IgE directed toward sunflower oil, refined or cold pressed, could not be conclusively demonstrated. The Prausnitz-Küstner reaction with sunflower oils performed with one patient's serum was negative. Although the cold-pressed sunflower oil was found to contain a minute amount of protein, open challenge with the derivative oils resulted in no immediate or delayed reaction in the two patients studied. Sunflower oil ingestion in these patients who were highly sensitive to the parent material proved safe. Nonallergenicity of derivative products needs to be proven for each case.

Adult↗
PubMed1986

Ferrous iron transport in Streptococcus mutans.

Radioiron uptake from 59FeCl3 by Streptococcus mutans OMZ176 was increased by anaerobiosis, sodium ascorbate, and phenazine methosulfate (PMS), although there was a 10-min lag before PMS stimulation was evident. The reductant ascorbate may have provided ferrous iron. The PMS was reduced by the cells, and the reduced PMS then may have generated ferrous iron for transport; reduced PMS also may have depleted dissolved oxygen. We conclude that S. mutans transports only ferrous iron, utilizing reductants furnished by glucose metabolism to reduce iron prior to its uptake.

Anaerobiosis↗
PubMed1985

Rat corticosteroid-binding globulin (CBG) biosynthesis by fetal hepatocytes in culture.

The ability of fetal liver to synthesize and secrete corticosteroid-binding globulin (CBG) was investigated using primary cultures of hepatocytes transplanted from 15- and 18-day-old rat fetuses. Analysis of culture medium, after labelling with [14C]leucine, by crossed immunoelectrophoresis, clearly demonstrated CBG, albumin and alpha-fetoprotein (AFP) secretion. The relative rate of CBG secretion was more important at the younger stage. Indirect immunofluorescence permitted localization of CBG in fetal hepatocytes. The results suggest that the high level of CBG found in fetal serum is mainly produced by the liver of the fetus itself.

Animals↗
PubMed1984

Oxygen toxicity in Streptococcus mutans: manganese, iron, and superoxide dismutase.

When cultured anaerobically in a chemically defined medium that was treated with Chelex-100 to lower its trace metal content, Streptococcus mutans OMZ176 had no apparent requirement for manganese or iron. Manganese or iron was necessary for aerobic cultivation in deep static cultures. During continuous aerobic cultivation in a stirred chemostat, iron did not support the growth rate achieved with manganese. Since the dissolved oxygen level in the chemostat cultures was higher than the final level in the static cultures, manganese may be required for growth at elevated oxygen levels. In medium supplemented with manganese, cells grown anaerobically contained a low level of superoxide dismutase (SOD) activity; aerobic cultivation increased SOD activity at least threefold. In iron-supplemented medium, cells grown anaerobically also had low SOD activity; aerobic incubation resulted in little increase in SOD activity. Polyacrylamide gel electrophoresis of the cell extracts revealed a major band and a minor band of SOD activity in the cells grown with manganese; however, cells grown with iron contained a single band of SOD activity with an Rf value similar to that of the major band found in cells grown with manganese. None of the SOD activity bands were abolished by the inclusion of 2 mM hydrogen peroxide in the SOD activity strain. S. mutans may not produce a separate iron-containing SOD but may insert either iron or manganese into an apo-SOD protein. Alternatively, iron may function in another activity (not SOD) that augments the defense against oxygen toxicity at low SOD levels.

Anaerobiosis↗
PubMed1984

Serum complement changes during double-blind food challenges in children with a history of food sensitivity.

Serum levels of C3, C4, factor B, properdin, total hemolytic complement and alternative-pathway hemolytic activity were measured before and after double-blind food challenge in 23 children with impressive histories of adverse reactions to foods. The 23 subjects had 11 positive food challenges and 12 negative food challenges. Nine patients with reagin-mediated positive food challenges showed increases in all six complement assays after double-blind food challenge, while the group with negative food challenges showed decreases in five of the six assays. The difference between the two groups for complement changes after double-blind food challenge was significant only for the alternative-pathway assay. Individual subject analysis revealed markedly heterogeneous changes in direction and magnitude within both groups for all complement assays. Therefore, it is concluded that measurement of serum complement levels is not a useful test for the clinical evaluation of a patient with suspected food sensitivity.

Adolescent↗
PubMed1982

The relationship of gastroesophageal reflux to nocturnal wheezing in children with asthma.

Gastroesophageal reflux (GER) has been reported in a high percentage of children with asthma. To investigate the relationship between GER and nocturnal asthma (NA), 25 pediatric patients with histories of NA were studied prospectively with three to 13 weeks of in-patient observation to document NA and quantitative day-time and night-time wheezing frequency. Two distinct groups of patients were identified: 17 patients with predominant day-time asthma (DA) and eight with prominent NA. All were studied with overnight esophageal pH recordings to detect GER during sleep while also monitoring clinical status. A reflux score (RS) was calculated to quantitate the severity of GER. Sixteen of 25 patients (64%) had abnormal GER, including all eight patients with NA. A significant positive correlation was found between the RS and the percentage of nights with wheezing, while age, serum theophylline level and pulmonary function at the time of study did not correlate with RS. The NA group also had significantly higher RS than the DA group. Three of the eight NA patients had the onset of clinical wheezing during an episode of GER. We conclude that there is a significant association between NA and GER independent of age, lung function and theophylline levels and that GER may induce NA in a subpopulation of patients with reactive airways.

Asthma↗
PubMed1979

Communicative disorders at a health-care center.

The purpose of this study was to identify the prevalence of communicative disorders in a Children and Youth Program during the 5-yr period 1973-1977. It appears that the numerous speech and hearing surveys recorded fail to do the following: (a) identify speech, language, and hearing pathologie from a comprehensive health-care center and/or hospital; (b) study types of clientele longitudinally; (c) study prevalence and needs of minority groups specifically; and (d) study prevalence of communicative disorders in preshool children. For the Black community under study, it appears that the prevalence of communicative disorders is greater than reported in other surveys. In addition, the current study identifies a community not receiving services. In reviewing the facilities available to this socieconomic community, one finds inadequacies. These inadequacies may be reflected in manpower and equipment rather than programs and resources. The data indicate a tremendous need to expand available services.

Adolescent↗
PubMed1977

Scalp distribution of early (0 to 10 msec) auditory evoked responses.

Auditory nerve and brain stem evoked responses were summated from multiple scalp and earlobe electrodes from five subjects with normal hearing to determine the spatial voltage relationships along the coronal and/or sagital planes that make up the electrode array. All recordings maintained their positive polarity, and polarity inversions were not observed at any cephalic sites; thus, a null potential line was not identified for these short-latency potentials at the scalp. Less distinct potentials were derived from the earlobes when referenced to the chin. Linked earlobes generated some potentials of negative polarity. These observations lend additional support to the concept that early auditory scalp potentials are most likely generated from far field neural aggregates located caudally to the auditory cortex.

Adult↗
PubMed1968

Direct comparison of the N-acetyl-l-cysteine-sodium hydroxide and the trisodium phosphate digestion methods for the culture of mycobacteria.

Comparison of sputum digestion procedures utilizing acetylcysteine-sodium hydroxide (AC) and trisodium phosphate for the isolation and culture of mycobacteria indicated that the AC procedure provides faster growth, thus permitting the earlier detection of positives. Also, in untreated patients and those in whom treatment has been recently instituted, the number of positives was slightly larger with the use of the AC procedure. However, of greater interest was finding that the AC procedure provided a larger quantity of positive cultures with sputum from subjects who had been intensively treated with antimicrobials and other drugs. Contamination was higher with the AC procedure, but when the sputa were diluted 1:10 this interference due to contamination was decreased.

Bacteriological Techniques↗
PubMedDate not supplied

The physicochemical and biological properties of alpha-fetoprotein depend of its ligand environment.

The majority of studies have concentrated on the endocrine and immunological roles of alpha-fetoprotein (AFP). These studies have been strongly orientated and sustained by research showing that rat and mouse AFPs competitively bind estrogen and non-esterified fatty acids. AFPs of other species, such as humans, are not estrogenophilic but all those studied to date bind NEFAs tightly. Endogenous ligands can greatly influence the conformation of the protein and consequently its biological activity. AFP may have three possible mechanisms of action: a) Murine AFP may be a modulatory element of estrogen expression which determines, under the control of NEFAs the concentration of the active free steroid. b) The protein could be transformed by bound ligands, so enhancing or inhibiting its binding to a target cell receptor, and consequently modifying its biological activity. AFP per se, can be the regulatory element. c) AFPs of all species can work as fatty acid binding proteins and modulate the availability of free NEFAs (not bound to protein). These free NEFAs can, in turn, act positively or negatively on various proteins involved in the pathways of the transfer of the steroid and peptide informations leading to cell multiplication or differentiation.

Animals↗