Desensitization of guanylyl cyclases in cultured human airway smooth-muscle cells

We previously showed that cultured human airway smooth-muscle cells (HASMC) contain soluble and particulate guanylyl cyclases (GCs). We studied the desensitization of soluble and particulate GCs in HASMC. Homologous desensitization of soluble GC occurred after incubation with S-nitroso-N-acetyl pencillamine (SNAP). SNAP-dependent desensitization was blocked by hemoglobin, a nitric oxide (NO) scavenger, suggesting that it was due to NO release. Cross-desensitization between SNAP and sodium nitroprusside (SNP) and the lack of thiol reduction after SNAP or SNP treatment suggested that thiol depletion was not involved. Assays for soluble GC activity and experiments using protein synthesis inhibitors suggested that SNAP-dependent desensitization was due to reduced soluble GC. Homologous desensitization of particulate GC occurred after pretreatment with atrial natriuretic peptide (ANP) accompanied by reduced particulate GC activity. Recovery required protein synthesis, suggesting that it was due to reduction in particulate GC. Homologous desensitization to either SNAP or ANP was not altered by phosphodiesterase (PDE) inhibitors, suggesting that increased PDE activity was not involved. Cross-desensitization experiments using SNAP and ANP and experiments using zaprinast to elevate cyclic guanosine monophosphate showed no evidence of heterologous desensitization. Our results suggest that pretreatment of HASMC with SNAP or ANP causes homologous, but not heterologous, desensitization of soluble and particulate GCs, respectively.     

The role of diabetes on the clinical manifestations of pulmonary tuberculosis

Objective Diabetes is associated with pulmonary tuberculosis (TB), possibly due to impaired immunity, and diabetes may exacerbate the clinical manifestations of TB. Our aim was to assess the role of diabetes in the clinical manifestations of TB. Methods We studied 1250 patients with pulmonary TB in an urban population in a cross‐sectional study in Tanzania. All participants were tested for diabetes and HIV co‐infection, and TB culture intensity was assessed. Levels of white blood cells, haemoglobin, acute phase reactants, CD4 count and HIV viral load were measured, and a qualitative morbidity questionnaire was used to identify the prevalence of disease‐related symptoms. Results Tuberculosis patients with diabetes had a higher neutrophil count (B 0.5 × 10⁹ cells/l, 95% CI 0.2; 0.9, P = 0.001) than non‐diabetic TB patients. Serum C‐reactive protein (B 18.8 mg/l, CI 95% 8.2; 29.4, P = 0.001) and alpha‐1‐acid glycoprotein (B 0.2 g/l, CI 95% 0.03; 0.3, P = 0.02) were similarly higher in patients with diabetes. Diabetes did not affect culture intensity or HIV status, but self‐reported fever was three times higher among participants with diabetes than in those without diabetes (OR 2.9, CI 95% 1.5; 5.7, P = 0.002). Conclusion Diabetes is associated with small changes in the manifestations of TB, but may have little clinical significance.     

Public reactions to child suicide: Effects of child's age and method used

In two separate experiments, a total of 180 citizens at a suburban shopping mall responded to questionnaires about a fictitious newspaper article describing a male child's suicidal death. In Experiment I (90 subjects), the child's age was reported as either 10, 13½, or 17. In Experiment II, an additional 90 subjects responded to a fictitious newspaper article describing a 10-year-old boy's suicidal death by gunshot, hanging, or drug overdose. Seventeen-year-olds who committed suicide were rated more psychologically disturbed than 13½- or 10-year-olds. Parents of 17-year-old suicides were liked more than parents of younger children. In the case of the 17-year-olds, respondents were more likely to say that they felt that the cause of death should not be publicly reported. Across all ages, fathers were perceived as significantly more psychologically disturbed by female than by male respondents. Children who shot themselves were rated more psychologically disturbed than children who overdosed, but parents were rated about the same regardless of the child's method of suicide.     

Does television induce suicidal contagion with adolescents?

In an attempt to assess what adolescents think they would do if they knew of previous adolescent suicides, 116 high school students viewed a videotaped vignette of a distressed high school student and were asked to imagine that they were she. They were then given an information sheet summarizing the vignette. One third of the information sheets contained an embedded sentence that two friends had recently committed suicide, another third a sentence that two friends had recently died in an airplane crash, and one third contained no embedded sentence. Subjects were then asked to rate the likelihood that they would engage in various behavioral alternatives (commit suicide, run away, abuse alcohol, drive recklessly, seek psychological help, try harder at school, adapt to the situation) and the degree to which they blamed the various situational factors described in the vignette (school, friends, alcohol, parents). Subjects also completed the Reasons fGr Living Inventory (RFL). The only significant difference across groups was the significantly higher score of the suicide group on the fear of social disapproval scale of the RFL. Adolescents may not be influenced by news about suicide or they may just deny such influence.     

Community attitudes toward childhood suicide and attempted suicide

To assess whether people's reactions to family members of child suicide attemptors were similar to reactions to family members of (a) actual suicides and (b) actual suicides that were preceded by a failed suicide attempt, 120 shoppers (60 men and 60 women) read and responded to one of five short newspaper articles about an incident of a 10-year-old child who either (a) attempted suicide, (b) committed suicide, (c) committed suicide after a previous suicide attempt, (d) died accidentally, or (e) died of a viral illness. Opinions about the psychological health of the victim and reactions to the surviving family varied depending on the nature of the incident. However, in many instances reactions to families of suicide attemptors could not be differentiated from reactions to families of actual suicides. Therefore, it is likely that the number of people affected by negative community reactions to suicidal behavior has been previously underestimated.