Respiratory distress syndrome in second-born versus first-born twins. A matched case-control analysis

The well-known increased risk of the respiratory distress syndrome in a twin born second as compared with the twin born first is usually attributed to the second twin's predisposition to depression at birth ("asphyxia"). We analyzed the etiologic roles of birth order, presentation, and depression at birth in the development of the respiratory distress syndrome in matched case-control populations drawn from 221 preterm twin pairs. Among the 39 twin pairs discordant for respiratory distress syndrome, the second twin was the affected member in 31 pairs. Second birth order was the only independent risk factor, but only in vaginal deliveries (matched odds ratio, 14.2; 95 percent confidence interval, 2.5 to 81.1). Second twins delivered abdominally did not have an increased risk relative to first twins (odds ratio, 0.9; confidence interval, 0 to 17.8). When depression at birth was evaluated as an outcome variable, malpresentation, rather than birth order, was the major risk factor (independent matched odds ratios of 2.7 [confidence interval, 1.0 to 7.5] and 1.3 [0.7 to 2.5], respectively). Thus, second twins' increased risk of respiratory distress syndrome cannot be explained by a predisposition to depression at birth; a more important factor may be that second twins do not benefit from the salutary effects of labor to the same extent as first twins.

Adrenocorticotropin, calcitonin, and antidiuretic hormone as tumor markers in patients with bronchogenic carcinoma of various histological types

We measured basal and dexamethasone-suppressed plasma ACTH in 246 patients with bronchogenic carcinoma (105 with small-cell carcinoma); in 138 of these patients (67 with small-cell carcinoma) basal and pentagastrin-stimulated serum calcitonin was also determined. In addition, in a subgroup of 120 patients (58 with small-cell carcinoma) plasma ADH with reference to plasma osmolality was also assayed. Non-suppressible plasma ACTH was found in 45% of patients with small-cell carcinoma but only in isolated cases of large-cell carcinoma, adenocarcinoma, and squamous-cell carcinoma. Serum calcitonin was increased in 28% of patients with small-cell carcinoma but only in few patients with other tumor types. Stimulation of calcitonin by pentagastrin was ineffective. Plasma ADH was inappropriately high in 47% of patients with small-cell carcinoma. Strikingly high also was the incidence of increased ADH concentrations in patients with large-cell (40%), adenocarcinoma (46%), and squamous-cell carcinoma (29%). By measuring plasma ACTH after dexamethasone suppression and ADH with reference to osmolality, the sensitivity of these tumor markers in detecting pathological hormone secretion is markedly increased. In small-cell carcinoma the simultaneous measurement of ACTH, ADH, and calcitonin gives a high yield of positive results (74%), indicating that this set of tumor markers is a promising aid in diagnosis and therapy control.

Impact of adjuvant chemotherapy on cosmesis and complications in stages I and II carcinoma of the breast treated by biopsy and radiation therapy

Cosmesis and complication rates were examined in patients with early stage carcinoma of the breast treated by biopsy and radiation therapy with and without adjuvant chemotherapy in an attempt to determine the effect of chemotherapy upon these parameters. Between April 1, 1975 and June 1, 1980, 51 patients were treated with radiation therapy and adjuvant chemotherapy (XRT + ACT) and 83 patients with radiotherapy alone (XRT). Chemotherapy usually consisted of cytoxan, methotrexate and 5-fluorouracil for 6 or 12 cycles. Minimum follow-up was 36 months. Cosmetic results deteriorated with time in both groups but to a greater extent in the XRT + ACT group. At 36 months, excellent cosmetic results were obtained in 73 of the 83 patients (88%) in the XRT group compared to 37 of 51 patients (73%) in the XRT + ACT group (p = less than .05). Comparison of the two treatment groups revealed that complication rates were significantly increased in the XRT + ACT group. Of the 51 patients in the XRT + ACT group, 21 patients (41%) suffered complications compared to 8 (10%) of the 83 patients in the XRT group (p = less than .001). This difference in complication rates resulted primarily from an increased incidence in the XRT + ACT group of wet desquamation in the electron beam portal used to treat the internal mammary lymph nodes and a trend towards a higher incidence of spontaneous nonpathologic rib fractures, myositis and arm edema. An increased incidence of nonbreast primary cancers was not seen. Our preliminary conclusions are that adjuvant chemotherapy has a negative impact upon cosmesis and complication rates in patients being treated with definitive radiotherapy. However, cosmetic results remain satisfactory and complication rates are maintained at an acceptable level. Continued close follow-up will be required before definitive conclusions can be reached as to the overall incidence and severity of the changes noted.

Randomized controlled trial of a nonpharmacologic cholesterol reduction program at the worksite

Under experimental clinical conditions diet modification has been shown to reduce serum cholesterol levels. This paper reports such a positive response to a nonpharmacologic, behavioral education program at the worksite. Employees at the New York Telephone Company corporate headquarters were assigned randomly to treatment and control groups. Treatment consisted of an 8-week group cholesterol reduction program conducted during employee lunch hours. It comprised a multiple-treatment approach--food behavior change techniques combined with nutrition education, physical activity planning, and self-management skills. The treatment group showed substantial change compared with the control group at the program's completion. Those treated displayed a significant 6.4% reduction in total serum cholesterol (266 mg% average at baseline) as compared with control subjects with a corresponding decrease in high-density lipoprotein levels. A significant increase in nutrition knowledge and moderate weight loss were also documented for this group. The magnitudes of a participant's baseline serum cholesterol level and his/her reduction in percentage of ideal body weight were positively and independently correlated with percentage changes in serum cholesterol levels. Over the same period, decreases in high-density lipoprotein levels and no changes in serum cholesterol, weight, and nutrition knowledge were observed for the control group. Overall, participants in the treatment program successfully reduced the coronary heart disease risk factors of elevated cholesterol and weight. Directions for future study are suggested.

Rapid 13C/12C turnover during growth of brown shrimp (Penaeus aztecus)

Using natural-abundance ¹³C/¹²C ratios as tracers, carbon turnover rates were determined for postlarval brown shrimp, Penaeus aztecus, in five laboratory growth experiments. Although tissue turnover in adult animals generally occurs during maintenance metabolism and is a function of time, turnover for young postlarval shrimp was accelerated during growth, and was primarily a function of weight gained rather than time. Metabolic loss of tissue carbon during growth was usually approximated by the function, Fraction lost=1-(initial weight/final weight). For shrimp that switch diets in the sea, model calculations show that this high turnover rate coupled with a four-fold weight increase suffices for shrimp to achieve a close isotopic resemblance of 1‰ or less (δ¹³C units) to the new diet.In accordance with these predictive calculations, shrimp which had increased in weight by a factor of four or more in the culture experiments showed essentially constant isotopic values reflecting their new diets. For these larger animals, the average animal-diet difference varied across three diets from-0.9 to +11‰, and the δ¹³C range among individuals was ≦1.4‰ in each experiment.