The plasma membrane-associated protein RS1 decreases transcription of the transporter SGLT1 in confluent LLC-PK1 cells

Previously we cloned RS1, a 67-kDa polypeptide that is associated with the intracellular side of the plasma membrane. Upon co-expression in Xenopus laevis oocytes, human RS1 decreased the concentration of the Na(+)-D-glucose co-transporter hSGLT1 in the plasma membrane (Valentin, M., Kühlkamp, T., Wagner, K., Krohne, G., Arndt, P., Baumgarten, K., Weber, W.-M., Segal, A., Veyhl, M., and Koepsell, H. (2000) Biochim. Biophys. Acta 1468, 367-380). Here, the porcine renal epithelial cell line LLC-PK1 was used to investigate whether porcine RS1 (pRS1) plays a role in transcriptional up-regulation of SGLT1 after confluence and in down-regulation of SGLT1 by high extracellular D-glucose concentrations. Western blots indicated a dramatic decrease of endogenous pRS1 protein at the plasma membrane after confluence but no significant effect of D-glucose. In confluent LLC-PK1 cells overexpressing pRS1, SGLT1 mRNA, protein, and methyl-alpha-D-glucopyranoside uptakes were drastically decreased; however, the reduction of methyl-alpha-D-glucopyranoside uptake after cultivation with 25 mm D-glucose remained. In confluent pRS1 antisense cells, the expression of SGLT1 mRNA and protein was strongly increased, whereas the reduction of SGLT1 expression during cultivation with high D-glucose was not influenced. Nuclear run-on assays showed that the transcription of SGLT1 was 10-fold increased in the pRS1 antisense cells. The data suggest that RS1 participates in transcriptional up-regulation of SGLT1 after confluence but not in down-regulation by D-glucose.

Blood pressure dysregulation syndrome. The case for control throughout the circadian cycle

Blood pressure dysregulation syndrome is characterized by abnormal swings in blood pressure following postural changes, meals, exercise, and during sleep. Although the syndrome may occur in normotensive individuals, a growing body of evidence suggests an association between blood pressure dysregulation and hypertension. Diagnosis can be aided using 24-hour ambulatory blood pressure monitoring. Improved understanding of the syndrome and heightened awareness of its existence in older persons can help clinicians provide more effective management of hypertension. Adequate control of blood pressure throughout the circadian cycle should be a treatment objective.

Observations on recurrent syncope and presyncope in 641 patients

BACKGROUND

Syncope is a common disorder that is potentially disabling and affects both young and old. Once neurological, cardiological, and metabolic causes have been excluded, there remains a group in which diagnosis is unclear; some may have an autonomic basis. We therefore did a retrospective study on consecutive patients referred to our tertiary referral autonomic centres between 1992 and 1998 with recurrent syncope and presyncope, in whom non-autonomic causes, before referral, had been sought and excluded. The object was to find out whether autonomic investigation helped diagnosis.

METHODS

Data from case notes and from the autonomic database on 641 patients were analysed. Syncopal patients with a known or provisional diagnosis of autonomic failure were excluded from analysis. The role of screening tests in establishing or excluding an autonomic cause was assessed. Response to additional autonomic tests (such as head-up tilt with or without venepuncture, and food challenge and exercise) was documented. Some patients underwent further testing if non-autonomic neurological, psychiatric, and other disorders were considered.

FINDINGS

Screening autonomic function tests indicated orthostatic hypotension and confirmed chronic autonomic failure in 31 (4.8%) patients. Neurally mediated syncope was diagnosed in 279 (43.5%) on the basis of clinical features and autonomic testing. Most had vasovagal syncope (227 [35%]); other causes included carotid sinus hypersensitivity (37 [5.8%]), and a group of 15 (2.3%) were associated with rarer causes such as micturition and swallowing. Miscellaneous cardiovascular causes (systemic hypotension, arrhythmias), or drugs, contributed to syncope in 53 (8.3%). Non-autonomic neurological causes included vestibular dysfunction (32 [5%]) and epilepsy (11 [1.7%]). In 56 (8.7%) a psychiatric cause was thought to be contributory. In 179 (27.9%), syncope was of unknown cause.

INTERPRETATION

In recurrent syncope and presyncope, when cardiac, neurological, and metabolic causes have been excluded, autonomic investigation can aid management by making, confirming, or excluding various factors or diagnoses.

Postural hypertension in elderly men--the Honolulu Heart Program

Postural hypertension is a condition in which the blood pressure rises abnormally during standing. The aim of this study is to determine the prevalence of postural hypertension and its association with morbidity and subsequent mortality. At the fourth examination (1991-1993) of the Honolulu Heart Program longitudinal cohort, 3741 Japanese-American men aged 71-93 were examined. Prevalence of postural hypertension in this cohort was 39%. Although there was a high prevalence of postural hypertension in this cohort, its clinical significance is questionable as there were no significant correlations with morbidity and subsequent mortality.

[Consensus on the diagnosis of multi-system atrophy]

We report the results of a consensus conference on the diagnosis of multiple system atrophy. We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible multiple system atrophy requires one criterion plus two features from separate domains. The diagnosis of probable multiple system atrophy requires the criterion for autonomic failure/urinary dysfunction plus poor levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite multiple system atrophy requires pathological confirmation.

Consensus statement on the diagnosis of multiple system atrophy

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate other domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poorly levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Consensus statement on the diagnosis of multiple system atrophy

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate other domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poorly levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Consensus statement on the diagnosis of multiple system atrophy. American Autonomic Society and American Academy of Neurology

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poor levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Gunshot wounds in children under 10 years of age. A new epidemic

Before 1980 we had not treated any children with gunshot wounds who were younger than 10 years of age, but the number has increased dramatically each year since then. Thirty-four children younger than 10 years of age were treated for gunshot wounds from 1980 to 1987. Sociologic and epidemiologic data were assessed by a child-abuse team and police. Other studies have concluded that gunshot wounds in young children were usually caused by unintentional injury, child abuse, or neglect. From our present study we add a further, and very disturbing, category, that of attempted or intentional pediatric homicide. The children in this category were shot in retaliation for gang activities of their older siblings. This study demonstrates that the majority of our patients' childhood gunshot wounds were related to gang violence and retaliation, the availability of handguns in the home, and child neglect. The prevalence of childhood gunshot wounds in the inner city is increasing dramatically.

Wolff-Parkinson-White syndrome presenting in atrial fibrillation

A case of atrial fibrillation in a patient with Wolff-Parkinson-White (WPW) syndrome is presented. In this case, the patient's ECG initially was misread as ventricular tachycardia. The therapy was appropriate for the actual condition, although electrical cardioversion and defibrillation eventually were required. The treatment of WPW with atrial fibrillation in this case consisted of lidocaine and procainamide. Verapamil, propranolol, and digoxin, which normally are indicated for WPW with tachyarrhythmias, are contraindicated for WPW with atrial fibrillation.