Biomedical subjects

R A Greenberg

Publications and source records attributed to R A Greenberg.

At least 19 recordsLinked to original sources

PubMed1992

Lower respiratory illness in infants and low socioeconomic status.

OBJECTIVES: Infants from families of low socioeconomic status are said to suffer higher rates of lower respiratory illness, but this assertion has not been carefully examined. METHODS: We studied the frequency and determinants of lower respiratory illness in infants of different socioeconomic status (n = 393) by analyzing data from a community-based cohort study of respiratory illness during the first year of life in central North Carolina. RESULTS: The incidence of lower respiratory illness was 1.41 in the low socioeconomic group, 1.26 in the middle group, and 0.67 in the high group. The prevalence of persistent respiratory symptoms was 39% in infants in the low socioeconomic group, 24% in infants in the middle group, and 14% in infants in the high group. The odds of persistent respiratory symptoms in infants of low and middle socioeconomic status were reduced after controlling for environmental risk factors for lower respiratory illness. Enrollment in day care was associated with an increased risk of persistent symptoms among infants of high but not low socioeconomic status. CONCLUSIONS: Infants of low socioeconomic status are at increased risk of persistent respiratory symptoms. This risk can be partly attributed to environmental exposures, most of which could be changed.

Acute Disease↗

PubMed1991

Passive smoking during the first year of life.

BACKGROUND AND PURPOSE: A description of passive smoking during the first year of life might assist planning preventive efforts. METHODS: Changes in the ecology of passive smoking were investigated in a sample of infants in central North Carolina followed from birth to one year of age. RESULTS: The prevalence of tobacco smoke absorption, indicated by excretion of cotinine, increased from 53 percent to 77 percent (95% CI of difference: 14, 35) during the first year of life. Most infants (92 percent) excreting cotinine at three weeks of age were also excreting it at one year. Moreover, 61 percent of infants not excreting cotinine at age three weeks were excreting it at one year. This increase reflected an increased exposure to household and, particularly, nonhousehold sources of smoke; the proportion of infants exposed to nonhousehold smokers increased from 14 percent to 36 percent. CONCLUSIONS: These findings suggest that prevention of the onset of passive smoking should begin very early.

Adult↗

PubMed1990

Validity of the clinical alert on breast cancer.

In May 1988, the National Cancer Institute issued a clinical alert calling for the routine use of systemic adjuvant therapy for all node-negative breast cancers. Subsequent review of the data that the National Cancer Institute used as a basis for its endorsement revealed several limitations, including failure to consider cost-benefit ratios and failure to exclude late toxicities. The authors conclude that the issuance of the release was premature and that it does not attempt to balance the slight lengthening of disease-free survival against the overall population costs. It is suggested that physicians individually assess the potential merits of such a treatment regimen in each of their patients with node-negative breast cancer.

Breast Neoplasms↗

PubMed1989

Breast cancer risk: a review of definitions and assessments of risk.

The histopathological and biochemical characteristics of cells and multicellular structure of benign and malignant breast changes have highly significant implications as to the risk of acquiring and dying of breast cancer. Consequently, every breast biopsy merits highly specific histopathological characterization as well as assay for hormone receptors. Certain aspects of a woman's personal and family history may be associated with increased or decreased risk. Clinical application of these variables to the prediction of future outcome requires an understanding of the definitions of risk. These definitions must then be applied appropriately when assessing risk. The definition of risk used must be explicitly stated and consistently used. Provided is a review of the definitions of risk and the risk of acquiring breast cancer according to age, family history, and histopathological characteristics of benign breast biopsies. The highly variable relative risk of dying from breast cancer when diagnosed is also reviewed.

Breast Neoplasms↗

PubMed1989

Ecology of passive smoking by young infants.

This study provides a detailed description of passive smoking by 433 infants (mean age 18 days) enrolled from a representative population of healthy neonates in central North Carolina during 1986 and 1987. Sixty-four percent (276) lived in households with smokers or had contact with nonhousehold smokers. During the week before data collection, two thirds (184) of these 276 infants reportedly had tobacco smoke produced in their presence. Seventy-five percent of smoking mothers smoked near their infants. The amount smoked by the mother near the infant correlated with the amount smoked near the infant by nonmaternal smokers. Cotinine, an indicator of smoke absorption, was found in the urine of 60% (258) of all study infants. The amount smoked in the infant's presence, as well as the amount smoked farther away from the infant, especially by the mother, were the most significant correlates of the urine cotinine concentration. The results of this study suggest that efforts to reduce passive smoking in young infants should emphasize the importance of the mother's smoking behavior, smoke produced anywhere in the home, and household social influences on smoking behavior near the infant.

Cotinine↗

PubMed1989

Autoinoculated palmar pustules in neonatal candidiasis.

A 2-week-old infant had grouped pustules on the right hand, wrist, and antecubital flexure that appeared after the first week of life. The infant was seen repeatedly to suck the involved areas of the hand and wrist. Clinically typical candidiasis was noted in the oral cavity and the diaper area. Wright's-stained smears of pustular contents, potassium hydroxide preparations of pustular material, and scale from the diaper dermatitis confirmed the presence of pseudohyphae and budding yeasts in all the involved sites. This case demonstrates fairly typical manifestations of neonatal-onset candidiasis, with the unusual feature of unilateral upper extremity pustules that appeared to represent an autoinoculated cutaneous infection.

Candidiasis, Cutaneous↗

PubMed1988

Interval-by-interval Cox model analysis of 3680 cases of intraocular melanoma shows a decline in the prognostic value of size and cell type over time after tumor excision.

In a selected group of 3680 patients treated by ocular excision for uveal melanoma, 1178 deaths were attributed to this tumor during 20 years following ocular excision. Survival time was divided into intervals containing an equal number of deaths, and coefficients of the Cox statistical model were independently derived for each interval. This analysis revealed a statistically significant decline over time in the prognostic value of largest tumor dimension (LTD) and Callender cell type (CT). Mathematical considerations suggest that the prognostic value of parameters derived from other cancers may also decline with time following excision of the primary tumor.

Follow-Up Studies↗

PubMed1988

A stable linear algorithm for fitting the lognormal model to survival data.

The lognormal model can be fitted to survival data using a stable linear algorithm. When tested on 800 sets of mathematically generated data, this method proved more stable and efficient than the iterative method of maximum likelihood, which requires initial estimates of model parameters and failed to fit a substantial fraction of data sets. Though maximum likelihood yielded more consistent estimates of proportion cured, mean, and standard deviation of log(survival time), the linear normal algorithm may nevertheless prove useful for these purposes: (i) computing initial estimates of model parameters for the maximum likelihood method; (ii) fitting data sets that cannot be fit by this method; and (iii) deriving the lognormal model directly from cumulative mortality.

Algorithms↗

PubMed1987

Number of mitral cells and the bulb volume in the aging human olfactory bulb: a quantitative morphological study.

The present study documents the morphological changes in the aging human olfactory bulb. Eight bulb pairs from white females between the ages of 25 and 102 years were used. The number of mitral cells in layers IV and III was determined for each bulb and corrected for split cell error. Counts were made on 10-micron thick Nissl-stained sections at 250-micron intervals. The mean number of mitral cells per olfactory bulb at age 25 was estimated from linear regression to be 50,935; at age 60, 32,718; and at age 95, 14,501. The average loss over the time interval studied was 520 mitral cells per year. The volume of each bulb layer, except layer IV, was determined. The difference in the volume of each layer within individuals with age and the total volume with age was not significant (P less than 0.11). The estimated mean bulb volume was found to be 50.02, 43.35, and 36.68 mm3 at ages 25, 60, and 95 years, respectively. The estimated reduction in bulb volume per year increase of age was 0.19 mm3. The ratio of mitral cells to bulb volume for layer III decreased by 19.4 units for every year increase in age. No significant difference was found between the left and the right bulbs in regard to the number of mitral cells and the bulb volume. Histologically, the glomerular layer thickness as well as the mitral cell size and concentration per unit area decreased with age. The intrabulbar anterior olfactory nucleus was discontinuous, highly variable in size, and presumably variable even in neuronal numbers.

Adult↗

PubMed1987

Comparison of primary and secondary treatment in squamous oral cancer.

A popular rule of thumb has often prevailed in treating oral cancer: Try one modality first; if it fails, try the other--the chance for cure will still be good. To study this dogma, a group of 160 consecutive patients with oral cavity squamous carcinoma were reviewed. A hypothesis was formed: secondary treatment for recurrent cancer, whether surgery after radiation failure or vice versa, would salvage essentially as many patients as primary treatment, say within 15%. Results show a large difference in success rates between first and second treatments when all stages are considered together, a difference well over 15 percentage points. Regarding each stage separately, the largest difference occurs in stage II (28 percentage points); other stages exceed 15 point differences. No significant differences in successful salvage occur between "home" failures and "elsewhere" failures. Local recurrence was a major cause of failure in both groups (55%). We conclude that recurrence of oral squamous cancer after first treatment markedly reduces patients' chance for cure.

Aged↗

PubMed1987

Feasibility study of a head and neck (upper aero-digestive tract) cancer examination.

Nearly all of the requirements for a cancer screening program can be met for head and neck--upper aero-digestive tract (UADT)--cancers. These UADT squamous cancers have a clearly definable high-risk group (smokers, greater than or equal to 40 yr), known etiology (tobacco and alcohol), identifiable premalignant lesions, a high prevalence rate worldwide, and high curability with "early" diagnosis. However, a need exists for an efficient detection examination suitable for physicians and dentists alike. Such an examination was designed and field tested as a feasibility study. The examination consisted of a six-step, dentist-oriented, site-targeted, 10-minute procedure, including the use of a fiberoptic pharyngoscope. Two practicing dentists were instructed in the procedure and used it on a randomly selected, high-risk Health America, Inc.--Park DuValle Community Health Center population, who were voluntary responders to a questionnaire and a phone call. Analysis of results showed easy and reproducible teachability, a high degree of acceptance by dentists and examinees, accuracy, and low cost. Associated findings were the following: Of 6,206 respondents, ages 40 and over, 27% were current smokers; 29% were ex-smokers; and 33% never smoked. Of invited current and ex-smokers, ages 40 and over, 51% appeared for a single examination. Compliance emerged as the major problem. The feasibility demonstrated in this study appears to justify a larger, controlled investigation.

Adult↗

PubMed1986

Evaluation of size in prognosis of oral cancer.

Greatest surface diameter of a cancer, together with suspicion of regional node metastasis, forms the basis for prognosis through the clinical TNM staging system for many cancers. In oral cancer, however, surface size sometimes fails to correlate, or sometimes inversely correlates, with tumor aggressiveness. To shed light on the value of measuring size per se, 155 consecutive oral squamous cancers, treated by surgery, radiation, or a combination, were analyzed to find the degree of correlation between greatest surface measurement and pathologic nodal spread and control of cancer. In tumors less than 2 cm, size correlated with very few nodal metastases and with good prognoses; in tumors greater than 2 cm, increasing size did not show a corresponding increase in pathologic node metastasis or significantly worsening outcomes except for a few very large cancers invading adjacent structures. In conclusion, greatest surface diameter of an oral cancer, when greater than 2 cm, is an unreliable predictor of tumor behavior per se. A small pilot study suggests that tumor thickness may be a better predictor. A formal study of this is planned.

Aged↗

PubMed1986

A clinically useful method for combining gross and microscopic measurements to select high-risk patients after enucleation for ciliochoroidal melanoma.

An objective and reproducible method was devised for estimating the malignant potential of ciliochoroidal melanomas after enucleation. This method requires only a single, routine microslide from which nucleolar area and largest tumor dimension are measured. Previous studies have shown these measurements to be reproducible and highly correlated with mortality. To demonstrate a practical method for clinical application of these measurements, a Cox statistical model was derived from 200 cases supplied by the Armed Forces Institute of Pathology. The resulting model, when applied to 340 cases with known outcome from two independent laboratories, allowed subdivision of patients into groups that suffered a six-fold difference in mortality. These results suggest that a central registry, by applying this method to histologic slides from around the world, could provide information useful for the clinical management of patients enucleated for ciliochoroidal melanoma.

Actuarial Analysis↗

PubMed1986

Metastatic uveal melanoma. Correlation between survival time and cytomorphometry of primary tumors.

The length of survival time following enucleation was determined for 29 patients with primary malignant melanoma of the choroid and ciliary body who subsequently died of metastatic disease. Histologic sections of the 29 tumors were studied by standard light microscopic techniques and computerized morphometry. The largest diameter of each tumor was measured on the 37% formaldehyde-fixed, paraffin-embedded slides; a cell type was assigned to each tumor on the basis of histologic study, using the modified Callender cell-type classification system; and inverse standard deviation of the nucleolar area (ISDNA) was determined for each tumor by computerized morphometric analysis. The observed death-order of these patients was then compared with the death-order predicted by ranking cases in ascending order of age at treatment, size of tumor, cell type, and ISDNA. Using rank-order correlation coefficient tests, only the correlation between ISDNA rank-order and observed death-order was found to be statistically significant. We believe that the limitations of the modified Callender cell-type classification system in predicting length of survival time following enucleation are related to the relatively few categories (four) in which to classify tumors, whereas the ISDNA represents a continuous spectrum of unlimited categories. As such, ISDNA can be more discriminant in selecting tumors of high malignant potential.

Adult↗

PubMed1986

Enucleation vs cobalt plaque radiotherapy for malignant melanomas of the choroid and ciliary body.

Clinical risk factors were assessed prospectively in a nonrandomized concurrent observational study of 237 patients with posterior uveal malignant melanoma. One hundred forty of these patients were treated with enucleation, and 97 underwent cobalt plaque radiotherapy. Tumor size and location of the anterior tumor margin proved to be the most significant clinical risk factors for death from metastatic melanoma. When Cox proportional hazards modeling was used to adjust for recognized intergroup differences in risk factors, the effect of therapy (enucleation vs cobalt plaque radiotherapy) on survival time was not statistically significant. We discuss the implications of this study for a randomized clinical trial of enucleation vs cobalt plaque therapy or comparable forms of irradiation.

Adult↗

PubMed1986

Thickness as prognostic aid in upper aerodigestive tract cancer.

A retrospective review of records and microscopic slides was carried out on 151 patients, encompassing nine specific upper aerodigestive tract cancer sites, correlating depth of invasion with node metastases and outcome. In this preliminary descriptive study, thickness was found to be more closely related to node metastasis and to survival than was surface diameter in middle-stage tumors, particularly in tongue, floor of the mouth, buccal mucosa, gum, and soft palate sites. Thickness, depth of penetration, and bone involvement appear to represent the degree of general tumor aggressiveness better than does surface extent. A substitution of thickness measurement for surface diameter (T) in the present TNM staging system is suggested.

Carcinoma, Squamous Cell↗

PubMed1986

Geometry, growth rates, and duration of cancer and carcinoma in situ of the breast before detection by screening.

The purpose of this study is to report the time elapsing between the moment a breast cancer reaches threshold size that would permit detection and the size at actual detection defined as sojourn time (STt) using data from the Breast Cancer Detection and Demonstration Project (Louisville data and reported composite data from 27 centers) by dividing prevalence rates by incidence rates. The number of cellular generations (n) required to produce cancers of different volumes was calculated at threshold (nt), at detection (nd), and the difference between the two (nd - nt). By dividing the difference (nd - nt) into STt, the average actual or net tumor volume doubling time (DTact) in this interval have been estimated. The STt value for carcinoma in situ was 557 and for cancer it was 538. At ages 35-39, STt ranged from 365-456 days, by ages 70-74, 942-1383 days. The average DTact similarly varied with age, carcinoma in situ, cancer with negative axillary nodes, and cancer with positive axillary nodes over a range of 28-732 days (95% confidence). The estimated DTact in the predetectable period was manyfold less than the DTact measured for mammographically visible cancers, in keeping with the predictions of decelerating growth. Models of the cytokinetic and clinical behavior of breast cancer are discussed.

Adult↗

PubMed1985

Association of chronic cystic mastopathy, xeromammographic patterns, and cancer.

The Breast Cancer Demonstration and Detection Project in Louisville (BCDDP-L) screened 10,128 women for cancer. From this screening, another project evolved wherein those patients diagnosed as having chronic cystic mastopathy (CCM) were followed over a 10-year period to evaluate any association between CCM and breast cancer. In all, 1396 breast biopsies were performed, with 165 cancers being diagnosed either on initial screening or during subsequent years. Three of these are excluded, since histopathologic slides could not be obtained for central review. Of this group, cancer was associated with CCM in 116 specimens and without CCM in 46 specimens. One subset of 355 patients with biopsy-proven CCM but no breast cancer was followed for 6 to 12 years, for a total of 2443.5 woman-years of observation. Within this subset, a total of only four cancers occurred (4 cancers/2443.5 woman-years for 0.00164 cancers/woman-years). This incidence is not significantly different from the expected value. However, an estimate is provided as to the power of the test that could be obtained from a larger sample size derived from other BCDDPs. This group of 355 women was sorted into subsets by establishing a matrix matching ten histopathologic subdivisions of CCM against six subdivisions of Wolfe's xeromammographic (XM) patterns. The numbers of cancers in each cell of this matrix is reported. The results found no concentration of these four cancers in this matrix.

Adult↗