Reaching a stationary global population: what we have learnt, and what we must do

The onset of fertility decline in France during the late 18th century and broader decline during the last third of the 19th century in Western Europe and the English-speaking European colonies demonstrates that humans are willing to control their fertility. Fertility transition was a social phenomenon. It has also been observed that the idea of fertility decline can spread and be acted upon elsewhere. The events of the International Conference on Population and Development (ICPD) are described and the need to control population growth in sub-Saharan Africa is discussed. While the ICPD's advocacy of improving women's autonomy, status, education, and reproductive health is laudable, those goals are opposed to that of completing the demographic transition. The existence of this opposition indicates that there have been changes in longstanding intellectual and technical aid consensuses. In the wake of the ICPD, developed country governments may never again emphasize the need for family planning programs in developing countries. The largest effect of such a course will probably be upon the demographic transition in sub-Saharan Africa. However, those interested in improving reproductive health in the Third World may join forces with the population movement when they realize that well-funded family planning programs are the key to improving reproductive health services.     

Systolic and diastolic cardiac function time intervals and exercise capacity in women

PURPOSE: To determine the relationship between exercise capacity and resting cardiac function time intervals in women. METHODS: The noninvasive method of seismocardiography was used to measure resting cardiac intervals in 12 female subjects. On the basis of maximal treadmill time (Bruce protocol), two groups were studied and categorized as long duration runners (LDR; N = 6) or short duration runners (SDR, N = 6). The following resting atrial and left ventricular (LV) cardiac function time intervals were determined: atrial systole, LV systole, LV diastole, LV isovolumetric contraction, LV isovolumetric relaxation, LV ejection, LV preejection, LV filling, LV rapid filling, and Tei index. RESULTS: Heart rate (HR) (65+/-3 vs 61+/-4 b x min(-1) for LDR and SDR, respectively; P = NS) and atrial systolic time (75+/-6 vs 81+/-5 ms for LDR and SDR, respectively; P = NS) were similar between groups. LV systole (348+/-15 vs 302+/-8 ms for LDR and SDR, respectively; P < 0.05) and LV ejection (297+/-13 vs 247+/-7 ms for LDR and SDR, respectively; P < 0.01) were longer in LDR, despite a similar LV isovolumetric contraction time. There was a general trend for a shortened LV diastole in LDR with a significantly shortened LV isovolumetric time in LDR (80+/-8 vs 107+/-8 ms for LDR and SDR, respectively; P < 0.05). LV preejection was shorter in LDR versus SDR (LDR; 114+/-6 vs SDR; 130+/-3 ms, P < 0.05), and the Tei index was less in LDR versus SDR. CONCLUSIONS: Independent of HR, increased treadmill time in young women is associated with greater resting systolic time intervals and decreased diastolic cardiac function time intervals.     

Immunocytochemical localization of NaCh6 in cultured spinal cord astrocytes

The expression of the alpha-subunit of voltage-gated sodium channel 6 (NaCh6) was examined in cultures of astrocytes from E18 rat spinal cord by using an antibody specific for NaCh6. Stellate cells with processes and flat, pancake-like astrocytes are the two morphological types predominantly present in these cultures. The antibody to NaCh6 labeled clusters at the cell body and along the length of the processes in stellate, process-bearing cells. Weak staining was observed in the flat, pancake-like astrocytes. Together with previous studies (Black et al., Mol Brain Res 23:235-245, 1994, Glia 14:133-144, 1995) that show that stellate cells express NaChs II and III (but not NaCh I) and flat cells express NaCh II, these results support the conclusions that there are different patterns of sodium channel expression between flat and stellate astrocytes and that multiple channel isoforms are expressed within the same cell. This study also suggests that NaCh6 may contribute to the electrical properties found in stellate astrocytes.     

The effect of indomethacin on the cytokine cascade and body temperature following burn injury in rats.

This study investigates the hypothesis that indomethacin's ability to prevent "fever" following burn injury in rats is mediated via decreased plasma concentrations of IL-6, the putative mediator of increased body temperature. Sprague-Dawley rats had radio transmitters and osmotic pumps containing indomethacin placed in the peritoneal cavity. Seven days later full thickness scald burns to 50% of the body surface area were produced. Following burn injuries, daily blood samples were obtained from a carotid catheter for assay of lipopolysaccharide (LPS), interleukin-1alpha (IL-1alpha), IL-1beta, tumor necrosis factor-alpha (TNF-alpha) and IL-6. In addition, body temperature (T(B)) and activity index were obtained every five minutes by telemetry. There were four experimental groups: burn + indomethacin (B-In); burn + polyethylene glycol (Peg) (B-Peg); control + indomethacin (C-In); and control + Peg (C-Peg). Burned animals demonstrated a significant two-fold increase in plasma IL-1alpha levels (p=0.004) and a seven-fold increment in IL-6 (p=0.0001) through the 7th PBD, and indomethacin administration had no significant effect upon the cytokine plasma levels. There were no significant increases in IL-1beta, TNF-alpha or LPS in any group. Indomethacin eliminated the chronic increase in T(B) following burn injury, and this effect was not produced by changes in plasma levels of the endogenous pyrogens IL-1alpha and IL-6.     

Synthesis and evaluation of 3-trifluoromethyl-7-substituted-1,2,3, 4-tetrahydroisoquinolines as selective inhibitors of phenylethanolamine N-methyltransferase versus the alpha(2)-adrenoceptor.

A series of 3-trifluoromethyl-1,2,3,4-tetrahydroisoquinolines was synthesized and evaluated as inhibitors of phenylethanolamine N-methyltransferase (PNMT) and as inhibitors of the binding of clonidine at the alpha(2)-adrenoceptor. These compounds were found to be selective inhibitors of PNMT due to their decreased affinity for the alpha(2)-adrenoceptor, which was attributed to steric bulk intolerance around the 3-position of 1,2,3,4-tetrahydroisoquinoline (THIQ) at the alpha(2)-adrenoceptor and to the decreased pK(a) of the THIQ amine due to the 3-trifluoromethyl moiety. Overall, these compounds displayed less affinity for PNMT compared to previously studied THIQ-type inhibitors, except for 16 which was found to have good affinity for PNMT (PNMT K(i) = 0.52 microM). Compounds 14 and 16 proved to be the most selective inhibitors in this small series of compounds and are some of the most selective inhibitors of PNMT known (14, selectivity alpha(2) K(i)/PNMT K(i) = 700; 16, selectivity alpha(2) K(i)/PNMT K(i) > 1900). Compounds 14 and 16 are also quite lipophilic due to the 3-trifluoromethyl moiety and represent promising new leads for the development of new highly selective inhibitors of PNMT, which should be sufficiently lipophilic to penetrate the blood-brain barrier.     

What have we learnt about the cultural, social and behavioural determinants of health? From selected readings to the first Health Transition Workshop

The article explores the issue of whether the holding of an international workshop in Canberra in 1989, and the preparation of papers for it, increased our knowledge of the cultural, social and behavioural determinants of health and whether the publication of the proceedings placed new knowledge in the public domain. The approach adopted is to compare those proceedings with a collection of selected readings on the subject made shortly before as part of the same program and also with certain other publications. The conclusions reached are that, in addition to having stimulated interest in the field, the workshop and its proceedings furthered knowledge in at least five important areas: (1) the existence of mortality-prone households; (2) the impact of differing cultural situations of women in terms of individualism on their children's survival; (3) the mechanisms whereby maternal education is translated into child survival; (4) the impact of culture and ethnicity on mortality; and (5) indirect indices of the impact of care. The workshop failed to contribute to substantial advances (or draw attention to the lack of advance) in the following areas: (1) the measurement of Third World morbidity or health; (2) adult health transition; (3) the impact of radicalism or egalitarianism in communities other than Kerala and Sri Lanka on mortality; (4) the impact of lifestyle diseases on Third World mortality; (5) the identification of economically optimum mixes of social change and the provision of health services in reducing mortality and improving health; and (6) the employment of health transition knowledge in the reduction of mortality and the improvement of health.     

Evaluation of mammographic image quality: pilot study comparing five methods.

A radiograph is considered of high quality when it allows a radiologist to identify abnormalities with high sensitivity and specificity. Although many methods for assessing image quality have been devised, it is not clear which is most meaningful or how well these methods correlate with one another. A pilot study was undertaken to compare five methods of evaluating mammographic image quality. Each of the methods was used to form separate rankings of 11 mammographic system configurations. In two of the methods, observers (three radiologists and three physicists) subjectively ranked the "image quality" of radiographs of phantoms obtained with each configuration. The third method ranked the systems according to contrast as measured densitometrically with an aluminum step wedge, and the fourth, in terms of lowest to highest mean glandular radiation doses to the breast. In the final method, observers based their rankings on mammograms of patients. The intra- and interobserver variabilities of each ranking method were assessed, as well as the correlations between methods, by using standard nonparametric statistical tests. Intraobserver consistency was high with any of the image quality ranking methods; however, image quality rankings based on either of the two phantoms provided better agreement among observers than did rankings based on images of patients. Surprisingly, no significant degree of correlation was found between any two image quality evaluation methods. Our work may have two implications for the American College of Radiology Mammography Accreditation Program: (1) small variations in phantom scores do not necessarily correlate with subjective variation in image quality in radiographs of patients, and (2) when small numbers of radiographs are used, the assessment of the quality of mammograms of patients may vary considerably among radiologists.     

The neuromuscular effects of sevoflurane and isoflurane alone and in combination with vecuronium or atracurium in the rat

Sevoflurane was compared to isoflurane anesthesia alone and in combination with atracurium or vecuronium in 84 rats using the sciatic nerve—anterior tibialis muscle preparation. Both bolus injection and infusion rate techniques were used to evaluate these drug interactions. The ED₅₀ (dose which produced a 50% depression of twitch tension) of atracurium was 311 ± 31 and 360 ± 32µg·kg^–1 during 1.25MAC sevoflurane and isoflurane anesthesia respectively. The ED₅₀ of vecuronium was 190 ± 27 and 149 ± 14µg·kg^–1 during 1.25MAC sevoflurane and isoflurane anesthesia respectively. The mean infusion rates of atracurium and vecuronium required to maintain a 50% depression of twitch tension were 5.04 ± 0.7 and 2.02 ± 0.3mg·kg^–1·hr^–1. These infusion rates were 5.04 ± 0.7 and 2.02 ± 0.3mg·kg^–1·hr^–1 during 1.25MAC sevoflurane and 3.73 ± 0.3 and 1.81 ± 0.4mg·kg^–1·hr^–1 during 1.25MAC isoflurane anesthesia respectively. With both atracurium and vecuronium, the infusion rate required to maintain a 50% depression twitch of tension was inversely related to the concentrations of isoflurane and sevoflurane. The authors conclude that sevoflurane is similar in potency to that of isoflurane in augmenting a vecuronium or atracurium induced neuromuscular blockade in a dose-dependent manner.(Shin YS, Miller RD, Caldwell JE, et al.: The neuromuscular effects of sevoflurane and isoflurane alone and in combination with vecuronium or atracurium in the rat. J Anesth 6: 1–8, 1992)     

The efficacy and safety of low-dose corticosteroids for rheumatoid arthritis

Low-dose corticosteroids (defined as less than or equal to 10 mg/d of prednisone or equivalent) are used increasingly for the management of rheumatoid arthritis. They are frequently substituted for nonsteroidal antiinflammatory drugs (NSAIDs), particularly in patients with gastrointestinal or other intolerance to NSAIDs, or as "bridge therapy" while patients await the benefits of delayed-acting, disease-modifying agents. Despite their clinical acceptance, published data concerning efficacy are meager. Adverse effects to low-dose corticosteroids are not so frequent nor so severe as those that occur with higher doses. Nevertheless, alterations in glucose metabolism, cutaneous atrophy, cataracts, and glaucoma are common. Osteoporosis, steroid-myopathy, a steroid-withdrawal syndrome, and dysfunction of the hypothalamic-pituitary-adrenal axis appear in some patients. Osteonecrosis, gastrointestinal, cardiovascular, infectious, or neurological complications probably do not occur. Fetal wastage, prematurity, or congenital malformations have not been proven with this dosage.     

Assessment of maternal nutrition.

A booklet, "Assessment of Maternal Nutrition," has been published by the American College of Obstetricians and Gynecologists in cooperation with The American Dietetic Association as a useful guide for physicians, nurses, dietitians, and nutritionists. Nutritional risks during pregnancy are clearly outlined. Clinical, dietary, and biochemical factors, as well as medical, obstetric, and social factors, are delineated as components of nutritional assessment. An A.D.A. Liaison Committee had major responsibility for the development of the "Eating Habits Questionnaire," a tool to screen dietary intake for major deficits and excesses, which is included in the booklet. It should be useful also as a starting point for nutrition education. Additional evaluation of the use and reliability of the screening tool is recommended.