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Biomedical subjects

J A Gaines

Publications and source records attributed to J A Gaines.

At least 19 recordsLinked to original sources
PubMed1992

Variability in physician assessment of lesions in cutaneous images and its implications for skin screening and computer-assisted diagnosis.

BACKGROUND AND DESIGN: The diagnosis of skin lesions is a three-part process of (1) screening for abnormalities, (2) examining lesions closely for the presence of important clinical characteristics, and (3) choosing a diagnosis based on the clinical data gathered. The first step, screening for abnormal areas, is of particular interest for anyone wishing to understand and automate the diagnostic process. As part of ongoing research into lesion detection and measurement, we examined the reproducibility and reliability of dermatologists who were asked to screen sets of cutaneous digital images and high-resolution photographs for the presence of skin lesions. RESULTS: The intraobserver and interobserver variation in this task was considerable. The average reproducibilities and reliabilities were approximately 85%. The photographs did not produce significantly better overall screening results than the moderately low-resolution digital images. CONCLUSIONS: Even highly trained dermatologists appear to differ significantly in their initial interpretations of skin images, both from observer to observer and within observers from session to session. These differences were reflected in all measures of diagnostic sensitivity, reproducibility, and reliability assessed. The magnitude of this variation is relatively insensitive to the means used to measure it, and is not simply due to different individual standards for diagnosis. It is highly unlikely that this variation is attributable to the images themselves, since the overall results were nearly identical for moderately low-resolution digital formats and very high-resolution photographs. These findings have important implications for determining where errors may take place in dermatologic screening and for automating the process of detecting changes in skin lesions over time.

Dermatology↗
PubMed1992

Treatment of infants with acute diarrhea: what's recommended and what's practiced.

In 1985, the American Academy of Pediatrics (AAP) published a policy statement on the treatment of infants with acute diarrhea complicated by mild to moderate dehydration. To determine how closely physicians in the United States follow the AAP's treatment guidelines, a questionnaire was sent to 457 pediatricians and 360 family practitioners. The questionnaire presented a hypothetical infant with acute diarrhea complicated by mild to moderate dehydration and included questions regarding the number of such patients seen yearly, length of time used to rehydrate the infant, and how formula or solids are introduced following rehydration. Complete responses were received from 53% of pediatricians and 40% of family practitioners. The number of patients with acute diarrhea seen per year did not affect physician's treatment. Pediatricians and family practitioners responded similarly to most questions. Contrary to the AAP's guidelines to rehydrate in 4 to 6 hours, 62% of responding physicians extend the rehydration period to 12 to 24 hours. Also contrary to the AAP's recommendations, 62% of pediatricians and family practitioners use a lactose-free formula. The majority of responding physicians do follow the AAP's treatment guidelines to initiate feedings with diluted formula. Significantly more pediatricians than family practitioners advance to a full-strength formula within 1 day (P = .011). Fewer than 50% of physicians polled started solids within 24 hours as suggested by the AAP. Overall, the findings suggest that very few pediatricians and family practitioners follow all aspects of the AAP's treatment guidelines for infants with acute diarrhea complicated by mild to moderate dehydration.

Acute Disease↗
PubMed1990

Prospective comparison of plain abdominal radiography with conventional and digital renal tomography in assessing renal extracorporeal shock wave lithotripsy patients.

Most publications citing the effectiveness of renal extracorporeal shock wave lithotripsy have used plain abdominal radiography to assess residual calculi after treatment. We compared radiologist sensitivity and specificity in the detection of calculi on plain abdominal radiographs versus conventional film-screen and digital renal tomograms in extracorporeal shock wave lithotripsy patients. Of the patients 50 were imaged before and within 24 hours after lithotripsy. Six radiologists evaluated the resultant 300 studies for the presence and location of calculi. The mean sensitivity for digital tomograms was 83% for pre-lithotripsy and post-lithotripsy studies, which was significantly higher than for plain abdominal radiography and conventional tomography after lithotripsy. However, there were significantly more false positive stone diagnoses associated with digital tomogram interpretation. Signal detection analysis verified the over-all superiority of digital tomography for post-extracorporeal shock wave lithotripsy imaging. Calculus detection by conventional and digital tomography is superior to detection by plain abdominal radiography. However, because we did not perform delayed imaging, it is not possible to say what impact digital tomography might have on the management of extracorporeal shock wave lithotripsy patients.

Humans↗
PubMed1990

Observations of the posterior tibial nerve SEP of patients requiring extradural spinal surgery.

The cortical potentials evoked by posterior tibial nerve stimulation were examined in a series of 141 hospital patients requiring extradural spinal surgery. One hundred and five patients were neurologically intact, while in 36 some deficit was present. In the intact subjects, the absolute latencies of the main medium-latency peaks (N30, P40, N50, P60) were found to vary with height and age. There were no additional gender-related differences. The latencies of the deficit group were longer than those of the intact group but only marginally useful as a clinical discriminator; their amplitudes were not significantly lower than those of the intact group. A model for variations in SEP latency is suggested.

Age Factors↗
PubMed1989

Serum prostate-specific antigen and prostate pathology in men having simple prostatectomy.

Prostate-specific antigen (PSA) is a sensitive and specific serum marker for monitoring disease activity in men with prostatic carcinoma. Despite reports of elevation of levels of this analyte in men with benign prostatic hyperplasia, no information is available correlating the serum levels with the actual prostatic abnormalities in men having prostatectomy for presumed benign disease. In the present investigation, the authors compared preoperative serum PSA levels with prostate disease in 81 men with bladder outlet obstruction. Five pathologic groups were found: incidental high-grade carcinoma (n = 3), low-grade carcinoma (n = 11), acute inflammation (n = 16) with or without chronic inflammation, Prostatic intraepithelial neoplasia (PIN) (n = 25), and benign hyperplasia (n = 26). Serum PSA levels were significantly elevated in both low- and high-grade carcinoma, acute inflammation, and PIN when compared with the patients with benign hyperplasia with and without chronic inflammation. Within the four groups with elevated levels, use of PSA levels could separate only the high-grade cancer patients who were subsequently shown to have metastatic disease. Only one patient with simple hyperplasia had PSA levels in the abnormal range.

Adenocarcinoma↗
PubMed1989

Relationships between microvascular function and capillary structure in diabetic and nondiabetic human skin.

Despite the commonly held view that abnormalities in capillary morphology, in particular thickening of the capillary basement membrane, are partly responsible for diabetic ischemia, few studies have correlated anatomic and hemodynamic variables in the same diabetic subjects. In a previous study of 24 type II (non-insulin-dependent) diabetic subjects and 24 age-matched control subjects, we showed that a standard finger exercise vasodilated cutaneous forearm vessels nearly equally (51%), but the postarteriolar flow responded differently between groups. Nondiabetic subjects increased flow by recruitment of capillaries, whereas diabetic subjects did so by capillary flow augmentation. Moreover, resting permeability-surface area product (PS) to pentetic acid was 85% higher in diabetic than nondiabetic subjects. In this study, these same subjects had their forearm skin biopsied and examined morphometrically by electron microscopy for capillary radius, basement membrane thickness, endothelial cell density, and a folding index of luminal membrane reduplication. All morphological variables were correlated stepwise in a saturated, analysis of covariance model with the physiological results. The correlations were sparse and specifically excluded basement membrane thickness. The highest r2 value was .432 between resting PS and a ratio of capillary density to endothelial cell number per capillary. These studies show little evidence that diabetic microvascular physiological variables are tightly connected to morphometric changes except for minor permeability changes, which rise with capillary density and decrease with endothelial cell number. Because PS to pentetic acid is increased in diabetic subjects at any level of capillary density, it seems reasonable that permeability may be increased above that of nondiabetic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Capillaries↗
PubMed1988

An optimal morphometric method for quantitating wound epithelization.

A new, inexpensive method for quantitative evaluation of reepithelization of shallow split thickness wounds in piglets is described. Wounds, 2.2 X 2.2 cm and 0.4 mm depth are inflicted by an electro-keratome knife in domestic piglets. At a specific time after wounding, the wound area is excised and processed for histology. A computer simulation, based on a randomized systematic sectioning of an entire wound, was used to conclude that only eight sections from the 2.2 X 2.2 cm wound are needed for the final evaluation. The results showed that the above method allows for determination of the epithelization magnitude within +/- 5% at a 95% confidence limit. It was found that in 15 kg piglets 50% epithelization of the above wounds was achieved in 65 hr; however, there exists a great interindividual variability. The rate of epithelization is age dependent and significantly faster in 7 kg body weight piglets than in those weighing 40 kg. The epithelization rate was the same at both the wound edge and the center of the wound, stressing the importance of hair follicles as a source of epithelization.

Animals↗
PubMed1988

Risk factors for blood loss from adenomatous polyps of the large bowel: a colonoscopic evaluation with histopathological correlation.

In 27 patients with 74 colonic polyps we prospectively evaluated polyp-related risk factors and specific histopathological characteristics that might result in blood loss from these lesions. Each polyp was endoscopically bathed in saline which was then aspirated back into a syringe through a catheter and tested for presence of blood on a Hemoccult II slide. Forty-nine polyps were excised. We found the following: 1) A relatively small proportion of adenomas (approximately 11%) have a propensity to bleed. 2) Approximately 22% of polyp-bearing patients have a bleeding adenoma. 3) Risk factors for bleeding include polyp size greater than 1.0 cm, presence of a stalk, and cherry-red color; associated histopathological findings include marked vascular congestion and intramucosal lakes of blood. 4) Clinically detectable bleeding occurs after intramucosal hemorrhage in the polyp head and dissection of blood into the bowel lumen through the glandular or surface epithelium. Most polyps are small, sessile and pink, without histopathological features of hemorrhage and are unlikely to bleed. Therefore, patients with Hemoccult-positive stools in whom such neoplasms are found should undergo further study to detect other causes of gastrointestinal blood loss. High-risk polyps in otherwise asymptomatic patients can be held responsible for bleeding; in them colonoscopic polypectomy with follow-up Hemoccult testing is sufficient management. Only if bleeding persists is study of other parts of the gut essential.

Adenoma↗
PubMed1988

Cutaneous vascular spiders in cirrhotic patients: correlation with hemorrhage from esophageal varices.

Ninety-two consecutive male cirrhotic patients had esophagoscopy to determine the presence and size of varices, and a concomitant skin examination for assessment of cutaneous vascular spiders. Thirty-one subjects bled from varices within 10 days of the spider evaluation, and this group was compared to 61 individuals who never bled. Our results show that incidence of spiders (90%) and varices (91%) is nearly identical, that frequency of variceal bleeding is higher among subjects with spiders compared with those who lack these lesions (36% vs 11%, p less than 0.05), and that the spider profile may be useful to identify individuals who are at increased risk for variceal hemorrhage. Frequency of bleeding was 50% (p less than 0.01) when greater than 20 spiders were present and 63% (p less than 0.01) when multiple atypically located lesions were detected. Large spiders (greater than 15 mm) correlate best with large varices and have the strongest association with bleeding (80%, p = 0.0002). If evidence of benefit from prophylactic treatment of esophageal varices can be established, then elements of the spider profile may serve as a discriminating marker to assist in selection of appropriate patients for therapy.

Adult↗
PubMed1985

Persistent fetal circulation. Neurodevelopmental outcome.

Forty children who had persistent fetal circulation (PFC) were followed up for one to four years. At the most recent examination, 16 (40%) were normal, eight (20%) had neurosensory hearing loss, three (7.5%) were profoundly impaired, six (15.0%) had suspect or abnormal results of neurologic examinations exclusive of hearing loss, three (7.5%) had speech impairment and normal hearing, and one had a delay in motor development. The remaining three had clinically suspect speech. Neurosensory hearing loss correlated only with having a mother with insulin-dependent diabetes, hand-to-mouth facility on the Brazelton scale, and eight-month neurologic status. Earlier diagnosis of hearing loss may be facilitated by testing of neonatal auditory behavioral responses, neurologic status at eight months, and by attention to parental concern about abnormal speech development. Neonatal and infancy auditory screening are recommended in children who have PFC in the neonatal period.

Child Development↗
PubMed1985

Early identification of learning problems in neonatal intensive care graduates.

Most investigators have documented a notable frequency of educational problems in children who received treatment in the neonatal intensive care unit (NICU). Seventy-four children born between 1972 and 1976 and in NICUs were followed up prospectively. At ages 3 to 6 years, preschool development was within the normal range on the McCarthy scales. A school problem, defined as grade repetition and/or special help in school, occurred in 32 (48.8%). Those with school problems had significantly lower scores on the McCarthy scales at 4 to 6 years and on the Woodcock Johnson test than the group without school problems. Children with school problems were classified correctly 60.3% of the time by duration of neonatal hospitalization, and 72% to 80.9% of the time by preschool development. If replicable, the data indicate that potential school problems can be identified sufficiently early in NICU nursery graduates that intervention could be started before they enter school.

Child, Preschool↗
PubMed1979

Alternative pathway of complement activation in full term and premature infants.

Classical and alternative pathway complement levels were measured in the cord blood sera of 60 newly born infants, with weights ranging from 1200--4165 g. The impact of maternal illness and infant illness on the complement levels was also evaluated. The mean values for CH50, C3, C4, PH50, factor B, and properdin were all significantly less than normal adult levels (P less than 0.0001). All of the above determinations were significantly correlated with one another except for the relationship between properdin and factor B. CH50, PH50, C4, and properdin levels were significantly correlated with birth weight although there was much residual scatter. Neither maternal illness nor mild to moderate illness in the newborn altered the birth weight-complement relationships. Severe infant illness did significantly alter the relationship between birth weight and complement. However, the impact of this variable on the birth weight-complement relationships was not consistent among the various components. These inconsistencies and the small sample size preclude drawing any strong conclusions about severe illness and complement levels.

Adult↗
PubMed1979

Echocardiographic profiles of the long-term cardiac changes in cystic fibrosis.

In this echocardiographic study, assessment of the heart in children with cystic fibrosis has shown that changes occur in not only the right ventricle but also in the left ventricle and aorta, as compared with normal. Echocardiograms could be successfully performed in 34 of 37 patients. The thickness of the right ventricular anterior wall and the dimension of the right ventricular cavity were abnormal, even in patients with mild disease (National Institutes of Health [NIH] score for severity of disease of 85 or greater). Larger, older children with lower NIH score had disproportionately larger right ventricular anterior walls and cavities. The thickness of the septal wall, the thickness of the left ventricular posterior wall, and the aortic dimensions were increased in those with severe disease. The dimensions of the left ventricular cavity for the population were slightly but significantly smaller than normal in systole and in diastole throughout the course of the disease. This study demonstrates that echocardiography is an effective noninvasive means of assessing the long-term changes in children with cystic fibrosis. These changes occur in both sides of the heart and appear to worsen as the disease progresses.

Adolescent↗
PubMed1977

Immunodeficiency in patients with non-Hodgkin lymphomas.

Seventy-one previously untreated patients with non-Hodgkin lymphomas were studied with several readilyvailable tests of immune function: number of peripheral blood lymphocytes, serum immunoglobulins, and delayed hypersensitivity to six recall antigens. The results were correlated to histology (Rappaport classification), stage (Ann Arbor classification), the presence of symptoms, and survival. As a group, 38 patients with diffuse lymphomas exhibited marked impairment in reactivity to five of six antigens (p less than 0.03 to p less than 0.001). In addition, lymphopenia and reduced levels of serum IgA were found in association with diffuse histiocytic lymphoma. Among patients with diffuse lymphoma, lymphocyte number and skin test reactivity tended to be greater in those with localized disease or without constitutional symptoms, and survival was superior for patients free of symptoms (p less than 0.01). As a group, 33 patients with nodular lymphoma had normal numbers of lymphocytes, lower levels of serum IgG and IgA, and significant impairment of reactivity to two antigens (streptokinase-streptodornase and mumps; p less than 0.01); reactivity to three other antigens (Candida albicans, coccidiodin, and tuberculin) was normal. Survival for patients with nodular lymphoma was superior (p less than 0.01) compared to those with diffuse lymphomas. In summary, severe immunodeficiency was found in patients with diffuse lymphoma (particularly diffuse histiocytic lymphoma), and definite but much less severe immunodeficiency was characteristic of patients with nodular lymphoma.

Adult↗