Control of atrial natriuretic peptide secretion in patients with severe congestive heart failure

Congestive heart failure (CHF) is marked by activation of multiple hormone systems that increased peripheral vasoconstriction and produce sodium and water retention. Plasma atrial natriuretic peptide (ANP) levels are frequently elevated in patients with severe CHF and may act to counterbalance these hormonal actions. To determine whether CHF patients maintain a physiological response to the presumed major stimulus to ANP secretion, atrial stretch, 22 CHF patients and 8 normal volunteers were studied. Atrial distention was produced in 10 CHF patients with a mannitol infusion and in 12 with lower body positive pressure. Eight normal volunteers also underwent a mannitol infusion. Both stimuli provoked increases in plasma ANP levels in the CHF patients, and the relative increase in plasma ANP after mannitol was similar in the CHF patients and the normal volunteers. We conclude that ANP secretion responds to atrial stretch in CHF patients, suggesting maintenance of the physiological release of this peptide.     

Use of digital radiography to demonstrate the potential of naproxen as an adjunct in the treatment of rapidly progressive periodontitis

The effect of the non-steroidal anti-inflammatory drug, naproxen, in reducing periodontal disease activity was assessed in 15 patients with rapidly progressive periodontitis. All patients in this double-blind study were treated with scaling and root planing. Thereafter, 7 patients receiving 500 mg naproxen b.i.d. for 3 months, and 8 patients received placebo. Disease activity was assessed in three ways. First, alveolar bone height was determined using standardized radiography. Second, alterations in alveolar bone metabolism were assessed using 99m-Tc-methylene diphosphonate uptake prior to dosing and 3 months later. Finally, bone loss or gain was detected using digital subtraction radiography. In this study, conventional subtraction images were processed to isolate the area of change and superimpose the change on the original radiograph. This allowed determination of both the direction and location of osseous changes. There was significantly less bone loss as determined by analysis of bone height during the 3-month study in the naproxen-treated patients when compared to the placebo-treated patients (p < 0.001). Radiopharmaceutical uptake was significantly reduced in the alveolar bone in patients receiving naproxen (p <0.03), whereas no significant change was observed in the placebo-treated patients. Furthermore, the subtraction radiographs showed a significant increase in the proportion of teeth demonstrating bone gain in the naproxen-treated group. These findings indicate that naproxen may be a useful adjunct to scaling and root planing in patients with rapidly progressive periodontitis.     

STD-related knowledge, beliefs and attitudes of Xhosa-speaking patients attending STD primary health-care clinics in South Africa.

The primary aim of this study was to describe patients at sexually transmitted disease (STD) clinics in Cape Town, South Africa, in terms of gender, education and age differences relative to their STD knowledge and beliefs, their condom use, as well as their attitudes towards condom use and their condom-use behaviour. The information was collected with a view to developing a health education intervention. Structured interviews were conducted with 2978 randomly sampled Xhosa-speaking STD clinic attenders about their knowledge, beliefs and practices regarding STDs and related behaviours. More males (75%) than females (25%) presented for STD treatment. The majority of patients (92%) were younger than 35 years. Female patients were found to be more aware than male patients of the sexual nature of STD transmission, valued personal autonomy in sexual behaviour and expressed a greater need to use condoms. Males perceived STD symptoms to be more serious, had more misconceptions about the cause of STDs and also more negative beliefs and attitudes towards condom use. Only 34.9% of the patients reported using condoms in the last 6 months while only 24.5% reported regular use. Those who reported condom use were more knowledgeable about the sexual transmission of STDs and the effects of STDs on the neonate. They also had fewer misconceptions about the causes of STDs and perceived STD symptoms to be more serious, attached greater value to personal autonomy in sexual behaviour and condom use and had more positive outcome expectancies of refusing sex than those who never used condoms. The data suggest that targeted interventions directed at males will have to address their inadequate knowledge regarding STDs in terms of transmission, causes, consequences, prevention and cure. Their negative beliefs and attitudes towards condoms will need special attention, especially in view of their multiple partner behaviour. Interventions directed at females will need to improve their knowledge regarding STD consequences, causes, recognition of symptoms as well as improve their knowledge of aspects of prevention and cure. All interventions must facilitate personal autonomy in decision making about sexual behaviour and condom use for both men and women, through skills development programmes that promote self-efficacy in the individual and instil a culture of mutual respect of such in the community.     

Increased sensitivity to two-stage skin carcinogenesis of mice heterozygous for the repeated epilation mutation (Er)

Mice heterozygous for repeated epilation mutation (Er) have cutaneous abnormalities that result in repeated loss of hair. Skin papillomas and carcinomas occur spontaneously in such Er/+ mice. BALB/c mice are generally resistant to induced skin cancers. We investigated whether Er/+ heterozygous mice of BALB/c genetic background exhibit increased susceptibility to spontaneous and induced skin tumors. Although none of the Er/+ CXB(N5) mice spontaneously developed skin tumors, they exhibited increased sensitivity to the development of skin papillomas induced by an initiation-promotion regimen. Er/+ mice developed papillomas after 20 micrograms DMBA initiation in the absence of TPA promotion, but the same dose of DMBA was subtumorigenic in +/+ (sibling) mice. Although 15 weeks of TPA promotion resulted in similar tumor susceptibilities, tumor latencies and tumor frequencies in the 2 groups of initiated mice, the papillomas were qualitatively different. Er/+ mice developed more papillomas of the delayed promoter-independent type, which occur after termination of promotion. In contrast, +/+ mice developed more promoter-dependent papillomas, which regress after termination of promotion. Therefore Er/+ mice had a significantly higher number of papillomas than +/+ mice at the termination of the experiment. These results suggest that Er-mutation-induced skin defects not only lead to the repeated loss of hair, but also influence the mode of development of skin papillomas from carcinogen-initiated cells.