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Biomedical subjects

S L Brooks

Publications and source records attributed to S L Brooks.

At least 55 records · Page 3Linked to original sources
PubMed1989

The appearance of mental foramina on panoramic radiographs. I. Evaluation of patients.

The appearance of the mental foramen on panoramic radiographs can be classified as a continuous, separated, diffuse, or unidentified type. In a sample of 297 patients, the most frequent appearance was separated (43%), followed by diffuse (24%), continuous (21%), and unidentified (12%). There were no significant differences in foramen diameter or relative vertical position within foramen types or developmental stages of the dentition. It is strongly suspected that sometimes the radiographic landmark presumed to be the mental foramen may actually be the reappearance of the mental canal.

Adult↗
PubMed1987

Evaluation of panoramic dental radiographs taken in private practice.

Five hundred panoramic radiographs submitted to Delta Dental Plan of Michigan for preauthorization or claim processing were evaluated for frequency of occurrence of 15 categories of technical errors in patient positioning, film processing, and general film handling. Only one radiograph showed no errors. The average radiograph contained 2.2 positioning errors, 1.0 processing errors, and 1.5 miscellaneous errors, for a total of 4.7 errors. Of the 500 radiographs, 467 had positioning errors, 441 had processing errors, and 424 had miscellaneous errors. Diagnostic quality was judged to be adequate in 365 radiographs, inadequate in 91 radiographs and marginal in 44 radiographs. The severity of error was of more importance than the number of errors in the determination of diagnostic adequacy.

Diagnostic Errors↗
PubMed1986

A study of selection criteria for intraoral dental radiography.

This study was undertaken to determine whether adequate diagnostic information could be obtained from a thorough clinical examination supplemented with a limited number of intraoral radiographs, the exact number of films determined in each case by applying a set of historical and/or clinical selection criteria. The 100 patients in this study required an average of 8.2 periapical radiographs (range, 0 to 18), in addition to posterior bitewing films to complete the diagnostic process. Later evaluation of complete-mouth surveys on these patients revealed that no cases of periodontitis, no periapical lesions, and no impacted teeth were overlooked when selection criteria were used. Forty-two unsuspected abnormalities were found, but only three of these required treatment-a root tip close to the surface and enlarged follicular spaces distal to two clinically erupted third molars.

Adolescent↗
PubMed1985

Absorbed doses from temporomandibular joint radiography.

Thermoluminescent dosimeters were used in a tissue-equivalent phantom to measure doses of radiation absorbed by various structures in the head when the temporomandibular joint was examined by four different radiographic techniques--the transcranial, transorbital, and sigmoid notch (Parma) projections and the lateral tomograph. The highest doses of radiation occurred at the point of entry for the x-ray beam, ranging from 112 mrad for the transorbital view to 990 mrad for the sigmoid notch view. Only the transorbital projection a radiation dose to the lens of the eye. Of the four techniques evaluated, the lateral tomograph produced the highest doses to the pituitary gland and the bone marrow, while the sigmoid notch radiograph produced the highest doses to the parotid gland.

Bone Marrow↗
PubMed1982

Effects of diet and acute noradrenaline treatment on brown adipose tissue development and mitochondrial purine-nucleotide binding.

Feeding rats a highly palatable 'cafeteria' diet resulted in a two-fold increase in interscapular brown adipose tissue (b.a.t.) mass after only 3 d on the diet. No significant difference in DNA content of b.a.t. was noted between control and cafeteria-fed rats at this time but DNA content was elevated 2-3-fold in the latter group by day 30, and incorporation rates of tritiated thymidine into DNA were elevated in these animals after 5, 15 and 30 d of cafeteria feeding. A doubling of specific GDP (per mg protein) to b.a.t. mitochondria was seen in cafeteria-fed rats on days 3, 15 and 30 and total GDP binding in the interscapular depot was increased by 3-4-fold. Injection of the animals with noradrenaline (25 micrograms/100 g body weight) 1 h before killing caused 180 and 430% increases in b.a.t. mitochondrial GDP binding in control and cafeteria-fed rats respectively. Linear Scatchard plots of binding data obtained from 15 d control and cafeteria groups indicated a single class of receptor, with the same affinity for GDP in all animals, but the maximum number of binding sites was markedly elevated in cafeteria rats and was increased further after treatment with noradrenaline 1 h prior to sacrifice. When cafeteria-fed rats were returned to stock diet alone the differences in b.a.t. mass and GDP binding diminished but after 10 d brown fat mass and noradrenaline-stimulated GDP binding were still significantly higher than control levels. These data provide further evidence for the involvement of b.a.t. and its mitochondrial proton conductance pathway in diet-induced changes in thermogenic capacity.

Adipose Tissue, Brown↗
PubMed1981

Sympathetic activation of brown-adipose-tissue thermogenesis in cachexia.

Tumour-bearing mice spontaneously lose weight 8-9 weeks after implantation of a human hypernephroma, in spite of a normal food intake. Resting oxygen consumption was up to 40% higher in these animals than in sham-operated controls, but was significantly reduced by beta-adrenergic blockade with propranolol in the former group. The injection of noradrenaline caused a marked stimulation of the metabolic rate in all the animals, but the greatest response was seen in the cachectic mice. The brown-adipose-tissue mass was similar for both groups, but guanosine diphosphate binding to brown-adipose-tissue mitochondria (an index of thermogenic capacity) was significantly increased in tumor-bearing mice, and the injection of noradrenaline 1 h prior to sacrifice caused the greatest stimulation of binding in the cachectic group. These data suggest that the rapid weight loss of tumor-bearing animals may be due to a high metabolic rate which results from sympathetic stimulation of brown-adipose-tissue metabolism. The relevance of these results to cancer-induced cachexia in man is discussed.

Adipose Tissue, Brown↗
PubMed1980

Increased proton conductance pathway in brown adipose tissue mitochondria of rats exhibiting diet-induced thermogenesis.

It has recently been demonstrated that in rats induced to overeat by being fed a varied and palatable diet (the 'cafeteria diet') there is a marked increase in heat production which serves to reduce, or prevent, the development of obesity. This diet-induced thermogenesis is associated with increases in sympathetic activity, and with changes in brown adipose tissue. Following cafeteria feeding, brown adipose tissue hypertrophies and and exhibits increased lipolysis and an apparently greater thermogenesis in response to noradrenaline. These metabolic changes resemble those seen during non-shivering thermogenesis in cold-adapted rats, and it was proposed that non-shivering thermogenesis and diet-induced thermogenesis have a similar metabolic origin which depends on the unique capacity of brown adipose tissue for thermogenesis. During non-shivering thermogenesis heat is produced in brown adipose tissue through a proton conductance pathway across the inner mitochondrial membrane that dissipates the proton gradient generated by respiration. The activity of the proton conductance pathway can be modulated by purine nucleotides, and changes in the pathway seem to be related to the level of purine nucleotide binding to brown adipose tissue mitochondria. We now report results which indicate that the proton conductance pathway is augmented in cafeteria-fed rats, and suggest that it operates to dissipate their excess energy intake through diet-induced thermogenesis

Adipose Tissue↗
PubMed1979

A clinical trial of topically applied 3 percent vidarabine against recurrent herpes labialis.

Seventy-six participants were enrolled in a clinical trial to determine therapeutic effectiveness of 3 percent vidarabine applied topically to recurrent perioral herpetic lesions. Following a 6- to- 12-month natural history phase, a 12-month clinical trial was conducted. Seventy participants developed 463 lesions during 361 episodes. Three percent vidarabine in a water-miscible gel was applied six times daily for 7 days to each lesion in the experimental group. Identically packaged placebo was used by the control group. Group assignment was by computer-generated randomization. Lesion size was reduced when vidarabine, rather than placebo, was applied. The difference was statistically significant (Student's t test, P = 0.02). Vesiculation followed tingling more rapidly when vidarabine, rather than placebo, was applied prior to vesiculation (P = 0.05). No significant difference between the two groups was found in episode frequency or lesion duration. Adverse reactions to vidarabine were not experienced.

Administration, Topical↗
PubMedDate not supplied

SV40-transformed fragile (X) amniocytes.

We report SV-40 transformation of female and male fragile X [fra(X)] amniocytes. In the transformants, fra(X) (q27.3) was detected in the 7th passage (9 cell generations) in fra(X) female amniocytes. It was conserved until at least the 20th passage (42 cell generations) although the frequency was reduced or became difficult to detect due to karyotypic evolution in the later generations. Similarly, for the male fra(X) amniocyte line, fra(X) was demonstrated at the 2nd passage (3 cell generations) and persisted until at least the 13th passage (29 cell generations). The prolonged period of reproductive potential of these transformed lines ranging from at least 29-42 generations suggests that the cryopreservation of significant quantities of early passage fra(X) transformed amniocytes will assure a reliable and continuous supply of positive control cells. These lines may be used for fra(X) prenatal diagnostic studies thereby improving the ability to quality control the particular fra(X) induction system being used.

Amniotic Fluid↗
PubMedDate not supplied

Mothers, infants, and DHA. Implications for nursing practice.

The purpose of this article is to describe the professional literature and current controversies concerning the relationship between essential fatty acids, especially Docohexaenoic Acid (DHA), and neurologic function. Although there is debate in the literature concerning just how much DHA is required for optimal neurologic functioning of infants, it is known that adequate DHA levels are dependent on an adequate dietary intake. However, common dietary practices today may not provide enough DHA. Because pregnancy and lactation are key times of rapid brain growth for the developing fetus and infant, nurses can be instrumental in teaching pregnant and lactating women diet-related information and promoting practices that help increase DHA levels. By understanding the importance of DHA in pregnancy and infancy, the nurse can take a more active role in essential health education.

Brain↗
PubMedDate not supplied

Cartoid artery calcification in a general dental population: a retrospective study of panoramic radiographs.

To determine the prevalence of carotid artery calcification and the degree of cervical spine imaging for three different brands of panoramic radiograph machines in a retrospective study, all panoramic radiographs exposed between January and June 1994 were reviewed for frequency of cervical spine imaging and radiopacities of the soft tissue in the region of the common carotid artery bifurcation. While carotid artery calcifications are not common in a general dental population, they can be found in up to 5 percent of older patients. Our data support panoramic radiography as a device that may identify patients at risk for developing a cerebrovascular accident, although we do not recommend making this radiograph for calcification detection alone.

Adolescent↗