Release of prostaglandins during reversal of one-kidney, but not two-kidney, one clip hypertension in the rat

Changes in systolic blood pressure and urinary excretion of PGE2 and 6-keto PGF1 alpha 24 h after removing the renal artery clip were compared in one-kidney and two-kidney, one clip Goldblatt hypertension in the rat. Unclipping the one-kidney rat returned blood pressure to normotensive levels within 24 h and was associated with a substantial increase in urinary PGE2 and 6-keto PGF1 alpha. Although hypertension was also completely reversed in the two-kidney model there was no significant change in urinary prostaglandin excretion. Prior treatment with indomethacin (6.0 mg/kg) markedly reduced urinary prostaglandins after clip removal in both forms of hypertension but attenuated the fall in blood pressure in the one-kidney model only. There were no significant changes in urinary kallikrein activity following unclipping. It is suggested that in the one-kidney, one clip rat prostaglandins are released as the result of exposing the unclipped kidney to elevated arterial pressure and that these contribute to the subsequent fall in blood pressure.     

Role of adenine in the pathogenesis ofMycoplasma pneumoniae infections of tracheal epithelium

Adenine sulfate and several related compounds were evaluated for their ability to retard the cytotoxic effect which normally accompaniesM. pneumoniae infections of hamster tracheal explants. Adenine sulfate, at the 0.01 mM level, was found to exert a significant protective effect. Little or no ciliostasis or loss of cell viability was detectable when organ cultures were infected with 10⁷ CFU of virulentM. pneumoniae in the presence of the adenine supplement. Mycoplasmas grew in broth and on plastic surfaces in the presence of adenine, and no significant diminution of growth rate or cell yield was detectable. Organisms adhered to the tracheal epithelial surface regardless of the presence or absence of adenine. When explants were incubated in the presence of¹⁴C-(8)-adenine, rinsed, and then infected withM. pneumoniae, the adenine label could be recovered from the mycoplasmas 20 h after the infection. These data are compatible with the known nucleic acid requirement of mycoplasmas and with a model which ascribes a role for purine/pyrimidine competition and/ or depletion in the infective process.     

Nurse-patient Interaction in the Home Setting

Nurses' interactive behaviors with perinatal patients in the home setting, as well as nurse-patient perceptions of home visits were examined. Data were obtained from 18 public health nurses and 55 perinatal patients. Results based on Bales's interaction process analysis revealed that 53.8 percent of the nurses' visits were related to asking for or giving information, while only 7.9 percent were categorized as friendly. Patients, however, perceived the nurses as friendly to them and others present. Although other differences in perceptions did emerge between nurses and patients, both groups were uncertain whether they had agreed on goals to work toward, which suggests the need for consumer involvement in the nursing process.     

Bone mineral status measured by direct photon absorptiometry in institutionalized adults receiving long-term anticonvulsant therapy and multivitamin supplementation

The effects of long-term anticonvulsant drug therapy and multivitamin supplementation on bone mineral status were evaluated by direct photon absorptiometry in 53 adult residents of an institution for the mentally disturbed. Results demonstrated a similar amount of osteopenia for control subjects and those on anticonvulsant drugs. Average osteopenia was 8% for control subjects and 6% for subjects taking anticonvulsant drugs. Significant osteopenia was found in 25% of subjects taking anticonvulsant drugs and 20% of control subjects. Multivitamin supplementation had a beneficial effect on bone status in both subject groups. The use of anticonvulsant drugs had a significant effect on levels of alkaline phosphatase. Elevated alkaline phosphatase was found in 37% of subjects taking anticonvulsant drugs and 22% of control subjects. Hypocalcemia was found only in subjects taking anticonvulsant drugs (19%). Average calcium values were similar for both subject groups. Multivitamins were shown to have no significant effect on alkaline phosphatase or calcium values. Because both control subjects and those taking anticonvulsant drugs showed similar levels of osteopenia, factors other than anticonvulsant drug therapy appeared to adversely affect bone mineral status in this population. Conversely, multivitamin supplementation and the dietary control present in the institutionalized setting appear to have ameliorated the osteopenia commonly seen in anticonvulsant-treated populations without greatly modifying elevated alkaline phosphatase and hypocalcemia.     

Changes in the β-endorphin content of discrete hypothalamic nuclei during the estrous cycle of the rat

Concentrations of β-endorphin were measured in discrete brain nuclei of 4-day cycling rats on each day of the estrous cycle. On the afternoon of proestrus β-endorphin levels were significantly higher in median eminence and suprachiasmatic nucleus, and lower in arcuate nucleus, when compared to levels found on other days of the cycle. These changes coincided with the peak of plasma prolactin, which was blocked by prior administration of naloxone.     

Extraocular muscle biopsy in chronic progressive external ophthalmoplegia

A quantitatives assessment of the pathological changes in extraocular muscle is presented in 8 patients with chronic progressive external ophthalmoplegia (CPEO). Serial cross-sections of extraocular muscle were stained with a battery of histochemical and immunohistochemical techniques and compared with 36 normal extraocular muscles and 1 muscle from a patient who had longstanding third nerve plasy with anomalous reinnervation. Several of the patients had a striking increase in the number of ragged-red fibers in extraocular muscle, particularly if frequent ragged-red fibers also were found on limb muscle biopsy. One patients demonstrated extrajunctional acetylcholine receptor (AChR) in a small percentage of fibers, although this finding was not present in the reinnervated muscle. Numerous darkly staining central regions were noted in the ocular muscle fibers of a patient with Stephens syndrome (CPEO, peripheral neuropathy, and cerebellar disease) and in the reinnervated muscle. A patient with myotubular myopathy had single central nuclei in both limb and ocular muscle. All patients demonstrated in their extraocular muscles variation in both the size and distribution of each of the three histochemical fiber types. Extraocular muscle biopsy proved to be a safe, reliable technique. As a similar quantitative analysis is applied to the study of further patients, a better understanding of the pathogenesis of CPEO should be possible.