Protein kinase-A and the effects of parathyroid hormone on phosphate uptake in opossum kidney cells

Current evidence indicates that signal transduction after receptor binding of PTH involves the stimulation of adenylate cyclase as well as stimulation of phosphoinositide metabolism. Recent studies, showing that PTH alters phosphate transport in opossum kidney cells at concentrations which do not increase cAMP production and that activators of protein kinase-C also alter phosphate transport, have led to the suggestion that there is a dual mechanism for the regulation of phosphate transport by PTH, namely, protein kinase-C at physiological levels of PTH and cAMP at higher levels of PTH. The present studies were designed to evaluate the relationship between cAMP-dependent protein kinase (PK-A), a more sensitive indicator of alterations in cAMP metabolism than measurements of total cellular cAMP, and phosphate transport in opossum kidney cells, in response to bovine (b)PTH 1-34 and [Nle8,Nle18,Tyr34]bPTH 3-34 amide. While bPTH 1-34 markedly stimulated cAMP accumulation (half-maximal stimulation between 1 and 10 nM), PTH 3-34 analog did not. Phosphate transport was inhibited in a dose-dependent manner by bPTH 1-34, with half-maximal effect occurring between 0.1 and 1 nM. [Nle8,Nle18,Tyr34]bPTH 3-34 amide also altered phosphate transport, although this peptide was 3 orders of magnitude less potent than bPTH 1-34. PK-A activity increased in response to bPTH 1-34 and correlated closely with the effects of PTH on phosphate transport. [Nle8,Nle18,Tyr34]bPTH 3-34 amide, which did not appear to increase cAMP, also resulted in a significant increase in the activity of PK-A. Studies of inhibition of cAMP accumulation using 2',5'-dideoxyadenosine demonstrated that while this agent markedly inhibited the accumulation of cAMP in response to PTH, the effects of PTH on phosphate transport were not altered. However, in spite of the reduction in cAMP the activation of PK-A was similar to control. These data indicate that the effects of PTH peptides on phosphate transport are more closely related to changes in the activity of PK-A than to levels of total cAMP. Activation of PK-A in response to PTH is demonstrable at the lowest doses of PTH that alter phosphate transport.     

Attitudes of rural and urban elderly concerning supplement use

To examine supplement purchase practices and attitudes toward supplements of rural and urban elderly, two questionnaires were designed. One questionnaire included demographic questions, an attitude scale, and questions concerning supplements purchases and sources of information about nutrition. The second questionnaire contained an advertisement about calcium supplements followed by questions regarding means to "improve calcium" and health concerns. The rural elderly had a significantly lower mean education level and a significantly higher number of misconceptions. The average expenditures on supplements were $52.00 per month for the total group and sources of information were media, physicians, family and friends. In response to the advertisement, nearly one-third of the respondents reported that they would be unlikely to take calcium supplements to improve calcium even though 86.7% stated they would take calcium supplements to prevent health problems and 51.7% believed there could be dangers in taking calcium supplements. The most commonly reported means to improve calcium were to increase milk and to eat cheese (86.7% each). Contradictions in the responses may indicate that these elderly are susceptible to advertising implying supplements are needed to prevent health problems.     

Etiological diagnosis of influenza A virus by enzymatic radioimmunoassay.

An enzymatic radioimmunoassay for influenza A virus was developed by using polystyrene beads coated with rabbit immunoglobulin G to capture viral hemagglutinins (H1 and H3). Captured hemagglutinin was detected with goat immunoglobulin G followed by affinity-purified rabbit anti-goat immunoglobulin G labeled with alkaline phosphatase. [3H]AMP was added to quantify alkaline phosphatase activity, and free [3H]adenosine was measured with a scintillation counter. The assay detected as little as 0.1 ng of purified hemagglutinin. It was specific for hemagglutinin subtype and, depending on the source of the goat immunoglobulin G used, detected either H1 or H3. There was no reaction with neuraminidase or core antigens of influenza strain WSN-33. The clinical efficacy of the assay was evaluated with sequential nasal washes from 33 patients with naturally acquired H1N1 influenza. In the first 3 days of infection, the assay was consistently less sensitive than the viral culture, although detectable antigen persisted in secretions longer than did the infectious virus. Testing of multiple samples greatly increased the number of individuals in whom an etiological diagnosis could be made by immunoassay (81% of patients were positive for viral antigens at some point in their illness), and such testing was necessary to achieve the sensitivity of a single culture. Mean antigen levels were highest in nasal washes with the highest titers of infectious virus.     

Use of live cold-adapted influenza A H1N1 and H3N2 virus vaccines in seropositive adults.

To investigate the immunogenicity and protective efficacy of cold-adapted influenza vaccine in individuals with underlying immunity to influenza A virus, we administered cold-adapted H1N1 and H3N2 vaccines to adults with prevaccination serum hemagglutination inhibition antibody titers of 1:16 or more and challenged them 1 month afterwards with homologous wild-type influenza A virus. Both cold-adapted vaccines were immunogenic in seropositive adults. In addition, individuals receiving cold-adapted vaccines had lower rates of virus shedding and illness following challenge with wild-type influenza virus than did unvaccinated seropositive volunteers.     

Basaloid carcinoma of the pancreas

A case of basaloid carcinoma of the pancreas in a 26-year-old woman is reported. The tumour was constituted by solid nests of relatively uniform neoplastic cells with hyperchromatic nuclei and scant cytoplasm, showing distinct peripheral palisading. There were necrotic areas and deposition of hyaline material, suggesting a basement membrane-like substance. Small foci of clear-cut squamous differentiation were present. Tumour cells were positive for cytokeratin 14 and P63 and negative for neuroendocrine and acinic cell markers. Ultrastructurally, the tumour was constituted by polygonal cells with round nuclei containing clumped chromatin. Occasional tight junctions and keratin filaments were present. Basaloid carcinomas may arise in several sites of the body, the most frequent being the anus and oesophagus, and have poor clinical outcome. The present case appears to be, to the best of our knowledge, the first documented example in the literature of basaloid carcinoma of the pancreas.