Congestive heart failure with normal ejection fraction. A different mechanism requiring different therapy.

Clinicians must remain undaunted when history, physical examination, and chest radiography suggest congestive heart failure but left ventricular systolic function is normal. Many of these patients have diastolic dysfunction, and standard therapy for left ventricular systolic dysfunction is often ineffectual or detrimental. Noninvasive testing is subject to many pitfalls but may confirm a clinical suspicion and provide indications to treat or to proceed with invasive testing. In the absence of clinical signs and symptoms of congestive failure, however, abnormal diastolic indexes should not be interpreted as diagnostic of diastolic dysfunction and are not an indication to treat.     

Effects of xylitol and fluoride on the response to glucose pulses of Streptococcus mutans T8 growing in continuous culture

Streptococcus mutans T8 was grown glucose-limited at pH 7.0 in a chemostat and pulsed, under pH free-fall conditions, with glucose, xylitol or a mixture of the two. Experiments were conducted in the absence or continual presence of low levels (1 mmol.l-1) of fluoride. Culture filtrates of samples taken at frequent intervals were assayed for carbohydrate and fermentation end-products. Fluoride had little effect on the organism's response to glucose until the culture pH fell to ca. 5.0, at which point the rate of lactate production was reduced some 3-fold. Xylitol affected the response to glucose but its effect was most marked in the presence of fluoride. Under these conditions, the rate of lactate production was reduced at least 3-fold, the pH did not fall to 5.0 and only about 50% of the added glucose was consumed. This suggests that xylitol can augment the metabolic effects on S. mutans of low levels of fluoride.     

Middle latency auditory evoked responses in normal term infants: a longitudinal study

Middle latency auditory evoked responses (MLAERs) were measured in 21 normal term infants, three to five days after birth and then at 6 weeks, 7 months and 1 year of age. A polyphasic waveform was elicited during natural sleep in all infants at each recording session by monaural click stimulation at a rate of 9 per second. A 70 dBHL stimulus was found to be optimal as the MLAER became less well defined when the stimulus intensity approached the threshold hearing level. The first 60 to 70 msec of the waveform was found to be most stable, with decreasing detectability of peaks at longer latencies. There was no change in wave latency or reproducibility of MLAERs recorded during different sleep states. Waves Po and Na showed a significant decrease in latency with increasing stimulus intensity at term and/or 6 weeks of age. This was not evident for the remainder of the waveform. Waves Po, Na, Pa, Nb, Pb and Nc exhibited significant decreases in latency with age, attaining values indistinguishable from adults by 7 months of age.     

Epidermal growth factor receptor expression in demented elderly: localization to vascular endothelial cells of brain, pituitary and skin

We have previously demonstrated that expression of epidermal growth factor receptor (EGFR) was upregulated on vascular endothelial cells from brains of patients with dementia but not in brains from non-demented patients. The present study used a monoclonal antibody against EGFR to examine its expression in pituitary gland, scalp, abdominal skin and brain of 29 patients with and without various dementias and neurological deficits, as well as normal aged controls. Of 20 clinically demented patients examined postmortem, 15 exhibited EGFR immunoreactivity (IR) on brain and peripheral vascular endothelial cells. Examination of nine non-demented patients revealed only 1 patient with EGFR-IR. EGFR-IR was expressed on all blood vessels, regardless of size or location within the tissue examined. Ultrastructural analysis of EGFR revealed that in pituitary, like brain, the receptor was restricted to the lumenal cell surface of vascular endothelial cells. In all cases of EGFR-IR there was an absolute correlation between central nervous system and peripheral expression; if there was EGFR-IR in brain vessels it was present in skin. If there was no staining in brain there was no peripheral skin vessel staining; and vice versa. Increased EGFR expression may indicate proliferative or regenerative changes in the vasculature of affected patients and may provide a biological marker supporting the diagnosis of dementia by analysis of skin biopsy.     

Aleurain: a barley thiol protease closely related to mammalian cathepsin H.

We have isolated and sequenced a 1400-base-pair cDNA derived from gibberellic acid-treated aleurone cell mRNA. This sequence contains an open reading frame that would code for a protein of 361 amino acids. The carboxyl-terminal two-thirds of the predicted amino acid sequence is closely related to that of the rat lysosomal thiol protease cathepsin H; the initial 143 amino acids may code for a secretory peptide plus a prosegment. The expression of this aleurone thiol protease mRNA is unusual in that, in aleurone cells, its abundance is regulated by the plant hormones gibberellic acid and abscisic acid, but it is also expressed at high levels in leaf and root tissue. This protease may represent the equivalent of a plant lysosomal thiol protease.