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Biomedical subjects

R Reid

Publications and source records attributed to R Reid.

At least 199 records · Page 11Linked to original sources
PubMed1986

Glycine-based oral rehydration solution: reassessment of safety and efficacy.

We evaluated the safety and efficacy of a glycine-based orally administered rehydration solution by comparing it with a standard oral rehydration solution (ORS) without glycine in a randomized double-blind trial in United States infants (age less than 15 months) given treatment for acute gastroenteritis as inpatients or outpatients. The response to therapy (stool volume and duration of illness) was similar in the two groups, except that in four (13%) of 31 hospitalized infants receiving glycine-ORS hypernatremia developed, (one had symptoms) compared with none of 35 receiving ORS (P less than 0.04). Among the 77 outpatients there were no differences between the groups. This study demonstrates that glycine-ORS did not provide any therapeutic advantage over standard ORS, and hypernatremia developed in some patients receiving glycine-ORS. We suggest that caution be used with this type of solution until further safety studies have been done.

Anti-Bacterial Agents↗
PubMed1986

Null mutations in the SNF3 gene of Saccharomyces cerevisiae cause a different phenotype than do previously isolated missense mutations.

Missense mutations in the SNF3 gene of Saccharomyces cerevisiae were previously found to cause defects in both glucose repression and derepression of the SUC2 (invertase) gene. In addition, the growth properties of snf3 mutants suggested that they were defective in uptake of glucose and fructose. We have cloned the SNF3 gene by complementation and demonstrated linkage of the cloned DNA to the chromosomal SNF3 locus. The gene encodes a 3-kilobase poly(A)-containing RNA, which was fivefold more abundant in cells deprived of glucose. The SNF3 gene was disrupted at its chromosomal locus by several methods to create null mutations. Disruption resulted in growth phenotypes consistent with a defect in glucose uptake. Surprisingly, gene disruption did not cause aberrant regulation of SUC2 expression. We discuss possible mechanisms by which abnormal SNF3 gene products encoded by missense alleles could perturb regulatory functions.

Cloning, Molecular↗
PubMed1985

Genital warts and cervical cancer. VII. An improved colposcopic index for differentiating benign papillomaviral infections from high-grade cervical intraepithelial neoplasia.

A new colposcopic sign (sharpness of peripheral margins) was graded into three objective categories representing subclinical papillomaviral infection, lower grade dysplasia, and grade 3 cervical intraepithelial neoplasia. Colposcopic features were prospectively recorded in 72 women and then correlated with histologic findings. Histologic diagnoses were evenly spread within the disease spectrum: 18 patients had subclinical papillomaviral infection without associated dysplasia; 15 had grade 1, 16 had grade 2, and 23 had grade 3 cervical intraepithelial neoplasia with or without koilocytotic atypia. Differences in the pattern of the peripheral margin were discriminatory throughout the entire diagnostic range. Predictive accuracy of this new colposcopic sign (79%) compared favorably with that of color (72%), vascular atypia (81%), and iodine staining (72%). Each criterion was independent of the other three. Hence, combining these four individual signs into a colposcopic index was 97% correct in forecasting approximate histologic findings. Because formulation of the colposcopic index is based on critical analysis rather than pattern recall, the use of this method will greatly simplify the otherwise arduous task of learning colposcopy.

Carcinoma in Situ↗
PubMed1985

Superficial laser vulvectomy. III. A new surgical technique for appendage-conserving ablation of refractory condylomas and vulvar intraepithelial neoplasia.

Despite the unique properties of the carbon dioxide laser, many surgeons do not know how to exploit the full potential of this sophisticated instrument. Effective laser operation on the vulva depends upon the accuracy of delineation of disease, the use of optimum power densities, and the ability to exercise precise control over depth of ablation. This article describes a surgical technique that capitalizes upon these principles, thereby maximizing the margin between favorable and poor outcomes. Superficial laser vulvectomy is a safe and efficient procedure in the hands of expert physicians, but should not be attempted by those who are less experienced. Indications for this operation and safeguards against surgical misadventure are also discussed.

Anal Canal↗
PubMed1985

Superficial laser vulvectomy. II. The anatomic and biophysical principles permitting accurate control over the depth of dermal destruction with the carbon dioxide laser.

The rationale for using the carbon dioxide laser to treat either vulvar intraepithelial neoplasia or extensive papillomaviral infections is to destroy the entire area of abnormal epithelium to a shallow depth, so that rapid healing will occur from normal keratinocytes in the underlying pilosebaceous glands. After the first laser impact, anatomic landmarks in the crater base are disguised by a layer of charred proteins, and any structure that is visible will already have suffered thermal necrosis. Accurate control of depth depends upon special surgical strategies that correlate the level of the underlying zone of thermal necrosis with specific visual appearances within the zone of vaporization. Maneuvers that limit depth of penetration to one of three desirable surgical planes (basement membrane, papillary dermis, midreticular dermis) are described.

Animals↗
PubMed1985

Superficial laser vulvectomy. I. The efficacy of extended superficial ablation for refractory and very extensive condylomas.

Sixteen refractory (present for more than 1 year) and 16 very extensive (affecting greater than 60% of the vulva or multiple lesions greater than 1 cm) condylomas were treated by superficial carbon dioxide laser ablation of all papillomavirus-infected epithelium within the lower genital tract. Accurate depth control was maintained by using a special surgical technique to create a plane that limited penetration to the basement membrane. All patients were healed within 3 to 5 weeks, without scarring or significant complications. Of 16 patients with extensive condylomas, 15 were cured by the first laser therapy and the other patient by a second treatment. In contrast, only five of 16 refractory condylomas responded to the first operation, seven to a second procedure and another three to a third treatment. Thirty-one of these 32 patients were finally cured by superficial laser vulvectomy. The other patient required deep dermal destruction and skin grafting. This 97% eventual success rate is encouraging, particularly since there are no other satisfactory alternatives in such difficult cases.

Adolescent↗
PubMed1985

Alterations in the phosphoprotein composition of tumor cell clones induced by cell culture techniques used routinely in assessing metastatic behavior in vivo.

To investigate whether the cell dispersion techniques commonly employed to harvest monolayer cultures of tumor cells for injection into experimental animals might induce alterations in cellular biochemistry, we compared the phosphoprotein profiles of 6 B16 melanoma clones of distinct metastatic potential using 2-D gel electrophoresis after growth in monolayer culture, after suspension by treatment, with trypsin/EDTA and after injection of suspended cells into syngeneic mouse plasma. Trypsin/EDTA treatment and subsequent exposure to syngeneic mouse plasma induced significant alterations in phosphoprotein composition in all clones. Most alterations were quantitative, involving either enhanced or diminished expression of specific phosphoproteins, but qualitative changes involving expression of novel phosphoproteins were also observed. None of the changes in phosphoprotein composition correlated with metastatic potential. The principle alteration induced in all clones by trypsin/EDTA involved enhanced phosphorylation of an NP-40-soluble component with a molecular weight of 79,000 and an isoelectric point of 6.3 [pp79 (6.3)]. This determinant was detected in extracts of B16 monolayer cultures but its level of phosphorylation was enhanced significantly by trypsin/EDTA treatment and by exposure of the harvested cells to syngeneic mouse plasma. These data indicate that procedures commonly employed to harvest tumor cells for assay of tumorigenic and metastatic potential may provide extensive alterations in phosphoprotein composition and that biochemical investigations of tumor cells grown in monolayer culture may not accurately reflect the metabolic status of the same cells immediately prior to and following i.v. injection into experimental animals.

Animals↗
PubMed1985

Directed elongation model for microtubule GTP hydrolysis.

We propose a role for GTP hydrolysis in microtubule assembly in which the GTPase reaction serves to stabilize tubulin subunits in the microtubule. The GTPase reaction in tubulin subunits containing GTP at microtubule ends is presumed to occur predominately in subunits at one of the interfaces between a cap of GTP-containing tubulin subunit and a core of GDP-containing tubulin subunit in the microtubule, resulting in elongation of the core. The proposed model interprets the effects of GDP on microtubule assembly, using a reaction scheme in which GDP-containing tubulin subunits are able to add to microtubule ends. The model can account for the GTP requirement for microtubule assembly, the GDP inhibition of the rate for microtubule elongation, and the fact that a metastable state exists after the enzymic conversion of GTP to GDP, with microtubules which are at steady state. To account for the fact that the microtubule assembly and disassembly rates are nonlinearly dependent upon the tubulin subunit concentration and for the effects of GDP-containing tubulin subunits on the kinetic properties of microtubules, our scheme includes nonproductive as well as productive binding of GTP- and GDP-containing tubulin subunits. We compare our model with an alternative scheme [Hill, T. L. & Carlier, M. F. (1983) Proc. Natl. Acad. Sci. USA 80, 7234-7238], which interprets the effects of GDP on microtubule assembly using a reaction scheme in which GDP is able to exchange with GTP in GTP-containing tubulin subunits in the microtubule and in which the principal GTPase occurs in GTP-containing tubulin subunits at the microtubule/solution interface.

Guanosine Diphosphate↗
PubMed1985

Malignant phaeochromocytoma.

Malignant phaeochromocytoma is a rare tumour and experience in its management is therefore limited. Five patients are discussed in whom the development of metastases was associated with rapidly progressive disease.

Adrenal Gland Neoplasms↗
PubMed1985

Invasive pulmonary haemangiomatosis.

Invasive pulmonary haemangiomatosis is a recently described disease in which exceedingly thin-walled vessels of capillary or venous dimensions infiltrate the lung parenchyma and pulmonary blood vessels. The angiomatous vessels, of obscure origin, infiltrate the media and intima of muscular pulmonary arteries, pulmonary veins and venules. The occlusion of the veins and venules by the thin-walled vessels, and the reactive intimal fibrosis they provoke, leads to pulmonary capillary dilatation, collections of intra-alveolar siderophages, fibrosis of alveolar walls and osseous nodules. This secondary pulmonary veno-occlusive disease in turn leads to hypertensive pulmonary vascular disease. Hence invasive pulmonary haemangiomatosis represents a fourth cause of 'unexplained pulmonary hypertension', the other three being unexplained plexogenic pulmonary arteriopathy, recurrent pulmonary thromboembolism, and pulmonary veno-occlusive disease. Two previously reported cases of invasive pulmonary haemangiomatosis presented with recurrent haemoptysis and the gradual development of chronic respiratory insufficiency associated with diffuse infiltrates in the chest radiograph. In one of these cases a haemothorax had developed. Such clinical features may be of importance in coming to the correct diagnosis.

Angiomatosis↗
PubMed1985

Role of soy-based, lactose-free formula during treatment of acute diarrhea.

A controlled study was conducted comparing the standard method of treating hospitalized infants with acute diarrhea (limited starvation) with the initiation of "early feeding" using a soy-based, lactose-free formula in infants of an American Indian tribe 12 months of age or younger. Forty-three patients, randomly assigned to group A, were given a soy-based, lactose-free formula four hours after hospitalization, and 44 patients, randomly assigned to group B, received standard therapy (food was withheld for the first 48 hours of hospitalization). After the first 48 hours, the same soy-based, lactose-free formula was given to the group B patients. Fluid intake and output of stool, urine, and vomitus were measured until the diarrhea resolved. Overall, group A patients showed less mean stool output (121 +/- 129 (SD) mL/kg) than group B patients (299 +/- 319 mL/kg) (P less than .001). Furthermore, the duration of illness was significantly shorter in group A patients (54 +/- 28 hours v 93 +/- 56 hours) (P less than .001). It was concluded that soy-based, lactose-free formulas can be safely used during the acute phase of diarrheal illness in infants and that their use shortens the duration of illness and decreases stool output in comparison with standard therapy.

Combined Modality Therapy↗
PubMed1984

Mechanism for nucleotide incorporation into steady-state microtubules.

We have extended our previous theoretical analysis of the kinetics for radioactive GTP incorporation into steady-state microtubules [Zeeberg, B., Reid, R., & Caplow, M. (1980) J. Biol. Chem. 255, 9891-9899] to include the effects of a kinetic barrier for equilibration of labeled GTP with the tubulin E site. This binding has been found to be relatively slow; the half-time for GTP dissociation is approximately 25 s (k = 0.028 s-1). The slow binding of radioactive GTP apparently accounts for the following observations: (a) more radioactive nucleotide is incorporated into steady-state microtubules in the first 20 s when tubulin-[3H]GTP is used in a pulse than when [3H]GTP is used; (b) when steady-state microtubules are pulsed for 20 s with tubulin-[3H]GTP and then chased with excess nonradioactive GTP, radioactive nucleotide incorporation is not stopped immediately. Quantitative analysis of these results indicates that our steady-state microtubules do not contain significant amounts (greater than 1%) of GDP or GTP which can exchange with added GTP. The principal route for labeled nucleotide incorporation appears to be from tubulin-[3H]GTP subunit uptake, by diffusional and treadmilling processes.

Animals↗
PubMed1984

Genital warts and cervical cancer. VI. The relationship between aneuploid and polyploid cervical lesions.

Human papillomaviral infection is now widely implicated in the causation of cervical neoplasia. Genotype analysis provides the best guide to biologic outcome; most polyploid lesions regress and most aneuploid ones persist or progress. This prospective survey examined the relationships between cell ploidy and 24 objectively validated criteria of human papillomaviral infection or premalignant change in 52 biopsies from a dysplasia clinic. Histologic evidence of benign warty expression and human papillomaviral capsid antigen production decreased steadily as DNA content ranged from diploidy to polyploidy to aneuploidy. In contrast, premalignant change increased with progressive distortion of nuclear DNA content. No absolute discriminants were found between polyploidy and aneuploidy, as evidenced by the detection of human papillomaviral proteins in three of 21 aneuploid epithelia and the recognition of abnormal mitotic figures in five of 17 polyploid lesions. Polyploid and aneuploid lesions differed only in severity, and it appears that some polyploid epithelia may be transition forms between diploidy and aneuploidy.

Animals↗
PubMed1984

Genital warts and cervical cancer. IV. A colposcopic index for differentiating subclinical papillomaviral infection from cervical intraepithelial neoplasia.

Five colposcopic signs (thickness, color, contour, vascular atypia, and iodine staining) were graded into three objective categories representing (1) subclinical papillomaviral infection, (2) lower-grade dysplasia, and (3) grade 3 cervical intraepithelial neoplasia. Seventy-two colposcopically different biopsy specimens (25 of subclinical papillomaviral infection and 18 of grade 1, 18 of grade 2, and 11 of grade 3 cervical intraepithelial neoplasia) were collected from 52 women and interpreted by validated, quantitative histologic analysis. Attempts to grade lesions by the prominence of the acetowhitening reaction or the mere presence of aberrant surface capillaries were unsuccessful. In contrast, each of five new colposcopic criteria were significantly correlated with histologic severity. Differences in color, vascular atypia, and iodine staining were more predictive than those of thickness and contour. Combined into a weighted index, these colposcopic features were 96% correct in forecasting approximate histologic findings. Because this method relies upon critical analysis rather than pattern recall, the use of this colposcopic index greatly simplifies the learning of colposcopy.

Animals↗
PubMed1984

Effect of a potent gonadotropin releasing hormone antagonist on pulsatile testosterone and gonadotropin secretion in the male nonhuman primate.

A potent gonadotropin releasing hormone (GnRH) antagonist [Ac-delta 3Pro1, pFDPhe2, DTrp3,6]-GnRH was given to adult male monkeys to determine the acute effect on pulsatile testosterone and gonadotropin secretion. Blood was drawn at 30 min intervals over 54 h without anesthesia using a mobile vest and tether assembly to support an indwelling catheter. After a 6 h control period, 0.1, 1.0, 2.0, 4.0 mg GnRH antagonist/kg bw in 1 ml corn oil sc, was given to intact adult male monkeys. The highest dose of GnRH antagonist decreased circulating testosterone within 6 h and for approximately 24-36 h duration. These data demonstrate that this GnRH antagonist can reduce serum testosterone both acutely and for intervals greater than 24 h and that the effective dose in intact animals is several-fold (up to 20 times) greater than in castrate animals.

Animals↗