The effects of the organophosphorous insecticides Dursban™ and Lorsban™ on the ciliated epithelium of the frog palate In Vitro

The ciliotoxic potential of the organophosphorous insecticides Dursban and Lorsban, their active ingredient, chlorpyrifos, and their carrier ingredients (Blanks) were assessed. Since chlorpyrifos inhibits acetylcholinesterase, the acetylcholine-innervated ciliated epithelial cultures of frog palate were used as the model. All compounds caused a decrease in frequency of ciliary beat over time. EC₅₀ values followed the same order as the time to inhibition. The orders were Lorsban > Dursban > chlorpyrifos, and Lorsban > Dursban Lorsban Blank > Dursban Blank. Stimulation of ciliary beating occurred immediately after exposure to all compounds, followed by inhibition. Dursban, Lorsban, and both Blanks elicited stimulatory effects in the presence of atropine. Atropine only blocked the initial stimulatory response with chlorpyrifos. In addition to chlorpyrifos, some component(s) of the inert ingredients were initially stimulatory but ultimately inhibitory to ciliary beating in the frog palate model. All compounds caused mitochondrial damage, including swelling, disruption of cristae, and loss of matrix.     

The vascular ‘sunburst’ appearance of osteosarcoma: A new angiographic finding

The angiographic analogue of the sunburst, (right angle) periosteal new bone formation in osteogenic sarcoma is described. The angiographic findings in this tumor and their relationship to the pathologic appearance are discussed.     

Environmental health services in primary care centers

Primary Health care centers supported by the Public Health Service through the Community Health Center and Migrant Health Centers programs are now required to provide environmental hazards directly related to clinical findings, but correcting community and occupational environmental problems may be pursued through appropriate agencies. State and local health departments will play key roles in the program in providing professional expertise in environmental health, assisting patients in taking corrective action, and assisting in the coordination with state, local, federal and voluntary agencies. Some primary care centers in areas of great need and limited resources will have their own environmental health professionals, but most will depend on local health departments for this specialty.     

The diagnosis of aortoiliac disease. A noninvasive femoral cuff technique.

An inexpensive femoral "cuff" developed in this noninvasive vascular laboratory allows pulse volume recordings and systolic pressure measurements of the femoral arteries. Using the parameters 1) femoral/brachial systolic pressure ratio, 2) wave amplitude, and 3) status of the dicrotic notch for assessment of results, it was found that the cuff correctly identified 59 of 62 limbs with at least 50% aortoiliac stenosis, with only two false-positive results, for an accuracy of 97%. The high, wide thigh cuff identified 57 of the 62 limbs, but had 45 false-positive results (77% accuracy). Use of the femoral "cuff" has refined the ability to identify the anatomic location of significant arterial stenoses in the lower extremities.     

Patterns of early lexical and cognitive development in premature and full-term infants

The linguistic and cognitive development of 26 premature and 27 full-term infants was studied longitudinally over the first 3 years of life. Infants in the premature population included 12 who were below 1500 g in birthweight and an even larger number with "at risk" signs. Language samples were collected in the home approximately every other month, the children were given experimenter-designed tests periodically, and mothers were asked to keep diaries of their children's lexical development. The children were given standardized tests as they exited the study. Cognitive development was also measured periodically. The patterns of lexical and cognitive development of the prematures did not differ markedly from those of full-term infants. There were no significant differences between the prematures as a whole and the full-term infants on standard language test measures as they exited from the study. There were significant differences between the very low birthweight and full-term infants on two of the exit measures. However, the performance of the very low birthweight infants was well within the range of normal on these two measures. The nature of the study and the factors that might have led to lack of differences between the two groups are discussed.     

Child mortality and fertility in Colombia: individual and community effects

The education of a mother is strongly and positively correlated with the survival rate of her children. This paper combines household data from the Colombian Census of 1973 and characteristics of the 900 residential areas in Colombia, to test various hypotheses concerning the mechanism by which mother's education and public policies affect child survival and the distribution of health benefits resulting from policy interventions. The hypothesis is advanced that education provides people with skills in acquiring and decoding new information and thus effectively lowers the costs of using more beneficial child health and contraceptive technologies. Since a primary function of health and family planning programs is to disseminate information on these same technologies, the hypothesis is tested that mother's education and these program interventions may substitute for each other in improving child health and reducing family size. The empirical analysis confirms that in urban areas the availability of medical services, family planning activities, transportational infrastructure and climate, in addition to mother's education, are associated with child mortality ratios and fertility within a birth cohort of mothers. The least educated mothers are the most strongly affected, in terms of their reduced fertility and increased child survival rates, by the local urban health programs. The evidence is, thus, consistent with the substitution hypothesis. No effects of program interventions and medical facilities are found on rural populations, though both child mortality ratios and fertility are lower for more educated rural women.     

Different inhibitory effect of adrenaline on platelet adenylate cyclase in the presence of GTP plus cholera toxin and of stable GTP analogues

Summary GTP is generally required for hormonal stimulation of adenylate cyclase. On the other hand, the presence of GTP is essential for hormone-induced inhibition of adenylate cyclase in cell-free preparations of human platelets and other cells. In order to differentiate the dual roles of GTP in hormonal stimulation and inhibition of adenylate cyclase, we have studied the effect of adrenaline on the platelet enzyme under conditions where guanine mucleotides caused marked stimulation. In the presence of GTP (1 M), which by itself had no or only a small stimulatory effect on adenylate cyclase, adrenaline inhibited the basal and prostaglandin E₁-stimulated forms of the enzyme. In contrast, the stable GTP analogues, GMP-P(NH)P and GTP--S, which caused a time-dependent, persistent activation of the enzyme, reversed or prevented the inhibitory effect of adrenaline. Cholera toxin, which activates adenylate cyclase presumably by inhibition of a specific GTPase, increased cyclase activity in platelet membranes up to 4-fold, and GTP addition (0.1–30 M) augmented this activation about 2-fold. The -adrenergic component of adrenaline (0.1–100 M), in a concentration-dependent manner, prevented the GTP-induced increase in cholera toxin-stimulated activity. The inhibition was also observed in enzyme preparations that had been fully activated by pretreatment with cholera toxin. These data suggest that -adrenergic agonists may inhibit platelet adenylate cyclase through increased inactivation of the enzyme, possibly involving a stimulation of the GTPase connected to the adenylate cyclase system.Abbreviations GMP-P(NH)P guanylyl 5-imidodiphosphate - GTP--S guanosine 5-(-thio)triphosphate - GTPase guanosine 5-triphosphatase - P_i inorganic phosphate. Parts of the data were presented in preliminary form (Jakobs and Schultz, 1978)     

The fate of the untreated alcoholic. Toward a natural history of the disorder.

Eighty-three male alcoholics were administered a structured interview when they appeared at a large general hospital for treatment of a variety of disorders. These represent 83 consecutive cases. None received treatment aside from brief "drying-out" but all were accepted as participants in a research program. Seventy-three (88 per cent of the sample) were located for a 3-year follow-up; five of these were not seen at the 1-year follow-up, and 10 were known to be dead. This paper focuses on 58 of the alcoholics who were seen at all three evaluations, and the 10 who were known dead. The data are presented as indicating the long term results of, at best, a mild or minimal intervention with male alcoholics. A small, but significant improvement was noted on several life-adjustment scales between the initial and 1-year evaluation (OYE), but no further improvement was seen between OYE and the 3-year evaluation (TYE); 19 percent were abstinent for 1 year and 10 per cent for the full 3-year period. The best predictor of TYE abstinence was OYE abstinence, but only for the extremes, i.e., no abstinence or total abstinence. Abstinence success was also related to a tendency to use community resources, lower number of mental hospitalizations, higher occupational status, higher global rating and, curiously, lower interpersonal adjustment rating. The group using Alcoholics Anonymous showed no better outcome than the group using no community resources at all. The mortality rate was 12 per cent over the 3 years or slightly more than 4 per cent a year. The suicide rate was about 4 per cent over the 3 years. The ratings for those dying showed a pattern of more admitted drunken arrests and heavy recent drinking superimposed on lighter overall drinking for the past year. The study demonstrates that even untreated alcoholics can be traced and effective follow-up studies completed. Results also indicate that over long time periods and left to their own devices, many alcoholics do seek out some form of help. But such assistance tends not to be sustained or intensive and a good portion of it is nonprofessional and nonmedical. Moreover, a surprisingly substantial number (31 per cent) of hospital-identified alcoholics apparently neither seek out nor receive any help at all after their initial identification; yet their self-reported life-adjustment ratings do not differ significantly from those who do seek help. The no-help receivers may be the most critical group of all to follow, as they are trule untreated. It would be important to determine how consistent in fact they are in their avoidance of help, what accounts for that behavior, and whether their ultimate fate is different from those who regularly seek assistance.