Promoting prevention in primary care: controlled trial of low technology,low cost approach.

A study is described in which three general practices were provided with low cost, low technology support from a "facilitator" and were compared with control practices in the ascertainment of major risk factors for cardiovascular disease in middle aged patients. Patients who were attending for a consultation with their general practitioners were recruited to make an appointment with a practice nurse for a health check, and this was compared with ordinary consultations in the control practices. Practices were helped by the facilitator to develop the nurse''s role. During the study the increase between intervention and control practices in blood pressure recording was doubled and in the recording of smoking habit it was quadrupled, and there was a fivefold increase in the recording of weight. This model can be applied to other aspects of prevention and general practice care.     

Specificity of endoproteinase Asp-N (Pseudomonas fragi): cleavage at glutamyl residues in two proteins

Endoproteinase Asp-N, a metalloprotease from a mutant strain of Pseudomonas fragi, has been reported to specifically cleave on the N-terminal side of aspartyl and cysteic acid residues. We utilized this enzyme to generate fragments for determining the amino acid sequence of the D-aspartyl/L-isoaspartyl methyltransferase isozyme I from human erythrocytes. Surprisingly, we identified cleavage sites for this enzyme at the N-terminal side of several glutamyl residues in addition to the expected cleavage sites at aspartyl residues. The ability of this enzyme to cleave polypeptides at both glutamyl and aspartyl residues was confirmed by mapping additional sites on erythrocyte carbonic anhydrase I. These results indicate that a more appropriate name for this enzyme may be Endoproteinase Asp/Glu-N.     

Preliminary purification and characterization studies of a low molecular weight, high affinity cytosolic lead-binding protein in rat brain

Carrier-free 203Pb has been used to label high affinity lead-binding proteins in rat brain cytosol to allow their initial characterization. The low molecular weight 203Pb-protein complex collected from a Sephadex G-75 column eluate has been further purified by Sephadex DEAE chromatography and then partially characterized. The protein has a molecular weight of 23,000 daltons as determined by SDS polyacrylamide gel electrophoresis and significant levels of glutamic acid (9.3%), aspartic acid (10.8%) and cysteine (9.4%). Western blot studies conducted using the polyclonal antibody to the renal lead-binding proteins showed a lack of reactivity, indicating that the brain protein is immunologically distinct from that found in the kidney.     

Stimulation of inositol phospholipid breakdown in pig brain miniprisms by carbachol and monoamines: effect of K+

1. The effects of carbachol, monoamines and K+ upon the rate of inositol phospholipid breakdown in pig brain miniprisms have been investigated. 2. In the striatum, carbachol (EC50 approx. 1 microM) and noradrenaline (EC50 approx. 25 microM) stimulated inositol phospholipid breakdown, whereas 5-hydroxytryptamine (1-1000 microM) was without effect. 3. The rate of inositol phospholipid breakdown was increased by raising the assay [K+] to greater than or equal to 40 mM. In the hippocampus and hypothalamus, a synergistic effect between K+ and carbachol was noted, whereas in the striatum, the effects were additive. 4. In striatal and hippocampal miniprisms, dopamine also increased inositol phospholipid breakdown, albeit only at high (greater than or equal to 1 mM) concentrations. Dopamine (1 mM) reduced the stimulation produced by noradrenaline (1 mM), suggesting that the effect of dopamine is due to a weak noradrenergic action of this catecholamine.     

Herpes simplex virus type 1-specific cytotoxic T lymphocytes recognize virus nonstructural proteins.

The specificity of herpes simplex virus type 1-specific cytotoxic T cells was examined with target cells expressing either input viral structural antigens or antigens resulting from permissive infection or cells from an interrupted infection in which they expressed predominantly nonstructural immediate-early proteins. These studies indicated that only an insignificant minority of cytotoxic T cells recognized the input viral antigens, whereas a significant proportion (20 to 35%) recognized target cells that expressed the immediate-early proteins despite the absence of serologically detectable viral antigens upon the infected cell surface. The finding that a significant proportion of cytotoxic T-cell populations obtained from the draining lymph nodes of mice acutely infected with herpes simplex virus type 1 also recognized immediately-early gene-expressing target cells indicates the importance of nonstructural herpes simplex virus proteins to antiviral immunity in vivo.     

Pavlovian conditioning of shock-induced suppression of lymphocyte reactivity: acquisition, extinction, and preexposure effects

Recent research has indicated that physical stressors, such as electric shock, can suppress immune function in rats. The present study investigated whether a nonaversive stimulus that had been associated with electric shock would also impair immune function. Presentation of that conditioned stimulus (CS) by itself produced a pronounced suppression of lymphocyte proliferation in response to the nonspecific mitogens, Concanavalin-A (ConA) and Phytohemagglutinin (PHA). In further evidence of a conditioning effect, the suppression was attenuated by extinction and preexposure manipulations that degraded the associative value of the CS. These results indicate that a psychological or learned stressor can suppress immune reactivity independently of the direct effect of physically aversive stimulation or of ancillary changes in dietary and health-related habits.     

Demonstration of the ascorbate dependence of membrane-bound dopamine beta-monooxygenase in adrenal chromaffin granule ghosts

Chromaffin granule ghosts from bovine adrenal medullae have been used to examine the ability of membrane-bound dopamine beta-monooxygenase to interact directly with intravesicular ascorbate and to investigate vectorial electron transfer from external ascorbate across the ghost membrane. Ghosts prepared by a modification of published procedures were shown to be fully active in both dopamine uptake and norepinephrine production. Dopamine uptake is dependent on the presence of a magnesium and ATP ionic complex, is abolished by reserpine, and reaches a steady-state level in the presence of dopamine beta-monooxygenase, ascorbate, catalase, and fumarate. Omission of ascorbate either inside or outside the ghosts greatly enhances dopamine accumulation, which reaches levels of approximately 30 nmol/mg under these conditions. Correspondingly, in the presence of all components, norepinephrine production reached approximately 100 nmol/mg in 30 min of incubation. Norepinephrine production was strictly magnesium-ATP-dependent, inhibited by either reserpine or dopamine beta-monooxygenase inactivation, and was markedly reduced when ascorbate was omitted from either inside or outside the ghosts. In the presence of limiting amounts of internal ascorbate, rapid norepinephrine production occurred which corresponded to the amount of initial ascorbate present, followed by a much slower endogenous norepinephrine production observable after complete depletion of internal ascorbate. The endogenous rate of norepinephrine production likely represents epinephrine-supported dopamine beta-monooxygenase turnover. Taken together, the data demonstrate that facile norepinephrine production by membrane-bound dopamine beta-monooxygenase occurs only when internal ascorbate is present, terminates upon depletion of internal ascorbate, and can only be sustained at a significant rate when reducing equivalents from external ascorbate are available.