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Biomedical subjects

G M Harrison

Publications and source records attributed to G M Harrison.

At least 37 records · Page 2Linked to original sources

Infant apnea: polygraphic studies and follow-up monitoring.

Twenty-six infants with unexplained and apparently life-threatening apnea were evaluated clinically, underwent eight- or 12-hour polygraphic recordings during sleep, and were then observed on home monitors. The one exception was an infant who was treated with theophylline and not monitored at home. Clinical evaluation revealed a history of vomiting in 19 infants, gastroesophageal reflux (GER) on esophagram in 19, and subtle neurologic abnormalities in ten. Polygraphic studies revealed questionable EEG abnormalities in nine infants, abnormal rapid eye movement (REM) time in four, prolonged apnea in one, and increased frequency of brief mixed (central and obstructive) and obstructive apneas in five. Of the 11 infants who underwent pH monitoring during their polygraphic sleep studies, seven had at least one recorded episode of GER, but the episodes were not accompanied by apnea or bradycardia. Thirteen infants had a subsequent episode of apnea that required stimulation, and in eight infants, cardiopulmonary resuscitation was given. There was two deaths. Two infants subsequently developed seizure disorders. Three of the five infants who underwent surgical fundoplication had recurrent apneic episodes. GER commonly occurred in these infant apnea patients but did not correlate with the clinical outcome. Although subtle abnormalities may be detected by sophisticated polygraphic monitoring studies, they are not predictive of recurrent apnea or death. Home monitoring may be useful in detecting the infant at risk for recurrent life-threatening apnea and in providing some safeguard for that infant.

Apnea↗

Specificity of an isolated salivary factor material to cystic fibrosis.

An oyster gill ciliostatic factor material has been isolated from the saliva of patients with cystic fibrosis (CF) by utilizing its ability to bind to alpha-amylase. It was quantitatively assayed by its ability to reversibly inhibit rabbit muscle glycogen debranching enzyme. The specificity of this CF factor material was investigated by comparing activities from the saliva of CF homozygotes (patients) varying in age, sex, and the severity of the disease; CF obligate heterozygotes (carriers); normal control subjects who had no family history of CF; non-CF asthmatic and allergic bronchitis patients; non-CF immunologically deficient patients with chronic respiratory problems; non-CF juvenile diabetic patients; non-CF pancreatic insufficiency patients; non-CF patients with obstructive liver cirrhosis; and non-CF patients with ectodermal dysplasia. The results show that the CF factor material isolated from CF saliva is specific to subjects with cystic fibrosis and is not associated with similar non-CE chronic disease states, nor is it produced as a result of an organ pathology associated with CF. There was no correlation between the amount of factor present in an individual CF homozygote sample and the severity of the disease. In the case of both the CF homozygote and heterozygote samples, there was also no correlation in either age or sex and the amount of factor present. The degree of inhibition produced by CF homozygotes compared to CF heterozygotes is characteristic of the autosomal recessive mode of inheritance of CF. This finding appears to associate the isolated CF factor material with the affected CF gene and suggests that the factor material is related in some way to the genetic lesion in CF.

Amylases↗

Cystic fibrosis: isolation and physical properties of a salivary cystic fibrosis factor.

A ciliostatic factor has been isolated from cystic fibrosis (CF) saliva by dialyzing it from purified alpha-amylase prepared by a glycogen-complex method. This method of isolating the CF factor is an improvement over the previously employed heparin procedure. The activity of the isolated factor is proportional with concentration using the oyster gill ciliostatic assay and in its inhibition of mammalian glycogen debranching enzyme. The ciliostatic action of the factor can be reversed by heparin under certain conditions. The type of inhibition of the debranching enzyme by the isolated CF factor indicates that its chemical structure is similar to that observed with hydroxyalkylamines and polyamine metabolites. Physical properties of the isolated factor indicate that it is of low molecular weight and is labile as a function of pH and temperature. At neutral pH the conditions under which it is maintained have a direct effect on the length of time that it is stable.

Animals↗

High-altitude pulmonary edema in children.

A 15-year-old boy with recurrent high-altitude pulmonary edema had previously been mistakenly treated for asthma and pneumonia. Clinical manifestations of this disorder, its etiology, treatment, and prevention are discussed.

Acclimatization↗

Comparison of three techniques of lung lavage in patients with cystic fibrosis.

One hundred fifty-three lung lavage procedures were performed on 81 cystic fibrosis patients during the years 1963 to 1976. Local analgesia was used in 24 lavages done via a rigid bronchoscope and in a group of 73 lavages directed by a fiberoptic bronchoscope. No abnormalities in cardiac rate or rhythm were observed with the lavages directed by fiberoptic bronchoscope. Fifty-six lavages were performed under general anesthesia with 20 cardiac abnormalities being noted among this group. Subjective improvement was noted in 96% of the 56 patients who had lavage under general anesthesia. Objective improvement was apparent in 45% of the 24 patients who had lavage with the rigid bronchoscope and 64% of the 36 patients who had lavage by fiberoptic bronchoscopy. It is concluded that patients with cystic fibrosis of varying stages of disability can more safety (and with good improvement) have bronchial washouts with the fiber-optic bronchoscope than with either of the other two techniques.

Adolescent↗

Cystic fibrosis: enzymatic detection of a ciliostatic factor.

The ciliostatic cystic fibrosis (CF) factor has been investigated in order to develop an enzymatic assay for its detection. In saliva, this factor is associated with alpha-amylase. Removal or addition of the factor by dialysis does not affect the alpha-amylase catalytic activity of CF or control (normal) saliva. Crude preparations of the dialyzable factor from CF saliva are ciliostatic. Alpha-Amylase-catalyzed starch hydrolysis from both CF and control saliva was found to be insensitive to hydroxyalkylamine inhibitors so this method could not be used to detect differences in CF and control amylase. Since another carbohydrase, mammalian debranching enzyme, is much more sensitive to inhibition, the effect of the isolated crude factor on this enzyme was determined. The mean values for percentage of inhibition of debranching enzyme activity by fractions obtained from saliva of CF patients, obligate heterozygotes, and control subjects are: 32% (27 samples), 13% (21 samples), and 6% (11 samples), respectively. Fifteen of the CF values exceed the maximum 13% inhibition observed for controls. Indeed, five samples almost completely inhibited debranching enzyme. This inhibitory action provides the basis of an enzymatic assay for the detection of the ciliostatic CF factor.

Amylases↗

Pseudomonas aeruginosa: immune status in patients with cystic fibrosis.

In order to have a better understanding of the clinical significance of Pseudomonas aeruginosa, circulating and secretory antibodies were measured. Of 100 patients diagnosed as having cystic fibrosis (CF) and an atypical mucoid P. aeruginosa cultured from their sputum, each possessed serum precipitins. These immunoprecipitates, however, were not detected in the sera of 40 CF patients, some of whom were chronically ill with pulmonary colonization by typically rough-smooth strains of P. aeruginosa. The sera of 46 CF patients and 27 CF patient parents not colonized by P. aeruginosa were negative for the precipitins. The sera from 15 of 45 chronically ill patients not having CF, however, but harboring P. aeruginosa, also possessed serum precipitins. The sera from 85 subjects not having CF and not clinically infected with P. aeruginosa were negative for precipitins. Serum hemagglutination titers as high as 1:4096 were measured in older CF patients having advanced pulmonary disease and who were infected with mucoid P. aeruginosa. Salivary titers ranged from 1:8 to 1:64. Increased levels of both circulating and secretory antibodies of the immunoglobulin A and G classes were demonstrated in patients with CF. Once a patient with CF becomes colonized with P. aeruginosa a process of conversion from the rough and smooth forms to the mucoid form is almost inevitable. Although the mucoid form predominates in the sputum, intermediates of the various colony types are often present. Serum precipitins were demonstrable only after the appearance of mucoid strains in the sputum of patients with CF. Although antibiotics tend to reduce the number of mucoid microorganisms, they are rarely, if ever, eradicated from these patients' lungs. Recurrent episodes of servere pulmonary infection and the evidence of increasing antibody formation to mucoid strains indicates the invasiveness of these particular strains.

Adolescent↗

Structure and ultrastructure of the labial salivary glands in patients with cystic fibrosis.

The morphology of the labial salivary glands in subjects with and without cystic fibrosis has been studied by light and electron microscopy. The terms ;light' cell, ;dark' cell, ;clear' cell, and ;myoepithelial' cell are used to describe the four cell types distinguished at the level of the electron microscope. The dark cells were found to stain specifically with alcian blue at and above pH 1.0, and the light cells to stain specifically using the periodic acid-Schiff (PAS) technique. This staining reaction suggests that an acidic mucosubstance is being produced by the dark cells and a neutral mucosubstance by the light cells. While no marked morphological differences were observed in the labial glands of patients with cystic fibrosis when contrasted with normal controls, it was observed that the cells from patients with cystic fibrosis contained quantitatively more mucus.

Adolescent↗