Functional differences in Kv1.5 currents expressed in mammalian cell lines are due to the presence of endogenous Kv beta 2.1 subunits.

The voltage-sensitive currents observed following hKv1.5 alpha subunit expression in HEK 293 and mouse L-cells differ in the kinetics and voltage dependence of activation and slow inactivation. Molecular cloning, immunopurification, and Western blot analysis demonstrated that an endogenous L-cell Kv beta 2.

Molecular physiology of cardiac potassium channels.

The cardiac action potential results from the complex, but precisely regulated, movement of ions across the sarcolemmal membrane. Potassium channels represent the most diverse class of ion channels in heart and are the targets of several antiarrhythmic drugs. Potassium currents in the myocardium can be classified into one of two general categories: 1) inward rectifying currents such as IK1, IKACh, and IKATP; and 2) primarily voltage-gated currents such as IKs, IKr, IKp, IKur, and Ito.

A novel K+ channel beta-subunit (hKv beta 1.3) is produced via alternative mRNA splicing.

Voltage-gated K+ channels can form multimeric complexes with accessory beta-subunits. We report here a novel K+ channel beta-subunit cloned from human heart, hKv beta 1.3, that has 74-83% overall identity with previously cloned beta-subunits.

Characterization of a voltage-gated K+ channel beta subunit expressed in human heart.

Voltage-gated K+ channels are important modulators of the cardiac action potential. However, the correlation of endogenous myocyte currents with K+ channels cloned from human heart is complicated by the possibility that heterotetrameric alpha-subunit combinations and function-altering beta subunits exist in native tissue. Therefore, a variety of subunit interactions may generate cardiac K+ channel diversity.

Activity of respiratory neurons during hypoxia in the chemodenervated cat.

Exposure of anesthetized paralyzed vagotomized peripherally chemodenervated cats to hypoxia results in initial depression and subsequent loss of the phrenic neurogram. To determine whether hypoxic respiratory depression results from the inhibition of respiratory premotor neurons by bulbospinal neurons of the Bötzinger complex (Böt-E neurons), extracellular recordings were made of dorsal and ventral respiratory group bulbospinal inspiratory neurons and Böt-E neurons during acute hypoxic hypoxia. All neurons recorded decreased firing rate during hypoxia.

Inhibition of voltage-dependent Ca(2+)-current by alpha-adrenoceptor agonists in smooth muscle cells.

The cellular mechanisms underlying the inhibitory effects of phenylephrine on dihydropyridine-sensitive, voltage-dependent Ca2+ currents recorded from single smooth muscle cells dissociated from the rat anococcygeus muscle were examined. Phenylephrine (0.1-30 microM) produced a concentration-dependent inhibition of the Ca2+ current; the maximum response occurred at a concentration of 10 microM, which inhibited the peak inward current evoked at 0 mV by 57.

Developmental changes in chest wall compliance in infancy and early childhood.

Development of chest wall stiffness between infancy and adulthood has important consequences for respiratory system function. To test the hypothesis that there is substantial stiffening of the chest wall in the first few years of life, we measured passive chest wall compliance (Cw) in 40 sedated humans 2 wk-3.5 yr old.

Hypoxia increases the activity of Ca(2+)-sensitive K+ channels in cat cerebral arterial muscle cell membranes.

The cellular mechanisms mediating hypoxia-induced dilation of cerebral arteries have remained unknown, but may involve modulation of membrane ionic channels. The present study was designed to determine the effect of reduced partial pressure of O2, PO2, on the predominant K+ channel type recorded in cat cerebral arterial muscle cells, and on the diameter of pressurized cat cerebral arteries. A K(+)-selective single-channel current with a unitary slope conductance of 215 pS was recorded from excised inside-out patches of cat cerebral arterial muscle cells using symmetrical KCl (145 mM) solution.

Alzheimer's care and service utilization: generating practice concepts from empirical findings and narratives.

Despite evidence of stress and strain, many of those who take care of relatives with Alzheimer's disease seem to resist using support services. Existing studies of the use of formal care by families of Alzheimer's sufferers are reviewed with special attention to findings relevant to access, particularly perceptions of appropriateness and acceptability or consistency with other needs and values. The conceptual model represented by these findings is then applied to a narrative that serves as a proxy for a real case that might confront a social worker.

The micropolitics of elder care in Memento Mori, Diary of a Good Neighbor, and A Taste for Death.

Using three novels--Muriel Spark's Memento Mori, Doris Lessing's Diary of a Good Neighbor, and P. D. James' A Taste for Death--we examine themes relating to the social construction of caregiving.

One positive impact of health care reform to physicians: the computer-based patient record.

The health care industry is an information-dependent business that will require a new generation of health information systems if successful health care reform is to occur. We critically need integrated clinical management information systems to support the physician and related clinicians at the direct care level, which in turn will have linkages with secondary users of health information such as health payors, regulators, and researchers. The economic dependence of health care industry on the CPR cannot be underestimated, says Jeffrey Ritter.

Comparison of community based service with hospital based service for people with acute, severe psychiatric illness.

Objective: To compare the burden on relatives and outcome of people treated for severe acute psychiatric illness by a community service and a traditional hospital based service.

Design: Follow up of patients aged 16-65 who required admission to hospital or home treatment for psychiatric illness during January 1990 to February 1991.

Setting: Two Birmingham electoral wards, Sparkbrook and Small Heath; Sparkbrook has a community based service and Small Heath a traditional hospital based service.

Enhanced single-channel K+ current in arterial membranes from genetically hypertensive rats.

Arterial smooth muscle from hypertensive rats shows an increased membrane permeability to K+ that depends on Ca2+ influx. To define the mechanism of this membrane alteration, we tested the hypothesis that Ca(2+)-dependent K+ current (IK(Ca)) is increased in arterial muscle membranes from genetically hypertensive rats. Single-channel K+ currents measured in cell-attached and inside-out aortic membrane patches from spontaneously hypertensive rats (SHR) were compared with those from normotensive Wistar-Kyoto rats (WKY).

Abdominal muscle activation by respiratory stimuli in conscious dogs.

The responses of the diaphragm, external oblique, and transversus abdominis muscles to hyperoxic hypercapnia and isocapnic hypoxia were studied in four awake dogs to test the hypothesis that central and peripheral chemoreceptor inputs result in different patterns of respiratory muscle activation. The dogs were trained to lie quietly in place, and electromyographic (EMG) discharges of the diaphragm (EMGdi), external oblique (EMGeo), and transversus abdominis (EMGta) were recorded from chronically implanted electrodes. Both hypercapnia and hypoxia recruited EMGeo and EMGta activity, but at comparable levels of minute volume of ventilation the EMG activity of the abdominal muscles was greater during hypercapnia than during hypoxia.

Localization of 24 cosmid clones on the human Y chromosome.

Twenty-four novel cosmid clones were cloned and mapped on the human Y chromosome using a panel consisting of DNA from seven individuals each having a different segment of the Y chromosome. Eight were assigned to the short arm, 15 to the long arm and 1 to the both short and long arms.

An evaluation of the usefulness of primary tumour expression of MCA and CA15-3 as prognostic indicators in breast carcinoma.

CA15-3 antigen and mucin-like carcinoma associated antigen (MCA) show potential as clinically useful serum markers of breast carcinoma. Recently, immunohistochemical versions of these monoclonal antibodies have become available but few data are available as to their clinical usefulness. The aims of this study were (i) to assess CA15-3 and MCA expression by primary breast tumours and to correlate tumour immunoreactivity with tumour behaviour, and (ii) to investigate the relationship between immunohistological staining and oestrogen receptor (ER) status.

Properties of the inactivating outward current in single smooth muscle cells isolated from the rat anococcygeus.

The properties of the voltage- and time-dependent outward current in single smooth muscle cells isolated from the rat anococcygeus were studied. The outward current was activated by depolarizations to membrane potentials positive to -40 mV. Activation followed third order kinetics; at +20 mV, the time for the current to reach half its maximal amplitude was around 55 ms.

On the determinants of persistent gambling behaviour. I. High-frequency poker machine players.

Persistent gambling was studied as a function of the reinforcement of arousal and winning during normal poker machine playing sessions. Play rate, heart rate, winnings, subjective excitement and expectations of winning were recorded for five male and five female high-frequency players. Autoregressive regression analysis indicated that wins affect play rate for up to three minutes, while effects of the other variables were inconsistent.

A Ca(2+)-dependent K+ current is enhanced in arterial membranes of hypertensive rats.

This study was designed to investigate the role and regulation of arterial membrane K+ channels in hypertension. Aortic segments from normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) were suspended for isometric tension recording. In other experiments, proximal aortic segments (PS) (exposed to high pressure) and distal aortic segments (DS) (exposed to lower pressure) were removed from surgically coarcted Sprague-Dawley rats and similarly prepared.

A preliminary report on the usefulness of monoclonal antibodies to CA 15-3 and MCA in the detection of micrometastases in axillary lymph nodes draining primary breast carcinoma.

The most critical factor affecting survival in patients with breast carcinoma is axillary nodal involvement. Monoclonal antibodies raised against specific human mammary tumour associated antigens may increase detection of micrometastases. This preliminary report examines two of these antigens; CA15-3 antigen and mucin-like carcinoma associated antigen (MCA) in the detection of such deposits.