Swelling activation of K-Cl cotransport in LK sheep erythrocytes: a three-state process.

K-Cl cotransport in LK sheep erythrocytes is activated by osmotic swelling and inhibited by shrinkage. The mechanism by which changes in cell volume are transduced into changes in transport was investigated by measuring time courses of changes in transport after osmotic challenges in cells with normal and reduced Mg concentrations. When cells of normal volume and normal Mg are swollen, there is a delay of 10 min or more before the final steady-state flux is achieved, as there is for swelling activation of K-Cl cotransport in erythrocytes of other species. The delay was shown to be independent of the extent of swelling. There was also a delay after shrinkage inactivation of cotransport. Reducing cellular Mg concentration activates cotransport. Swelling of low-Mg cells activates cotransport further, but with no measurable delay. In contrast, there is a delay in shrinkage inactivation of cotransport in low-Mg cells. The results are interpreted in terms of a three-state model: [formula see text] in which A state, B state, and C state transporters have relatively slow, intermediate, and fast transport rates, respectively. Most transporters in shrunken cells with normal Mg are in the A state. Swelling converts transporters to the B state in the rate-limiting process, followed by rapid conversion to the C state. Reducing cell Mg also promotes the A-->B conversion. Swelling of low-Mg cells activates transport rapidly because of the initial predominance of B state transporters. The results support the following conclusions about the rate constants of the three-state model: k21 is the rate constant for a Mg-promoted process that is inhibited by swelling; k12 is not volume sensitive. Both k23 and k32 are increased by swelling and reduced by shrinkage; they are rate constants for a single process, whereas k12 and k21 are rate constants for separate processes. Finally, the A-->B conversion entails an increase in Jmax of the transporters, and the B-->C conversion entails an increase in the affinity of the transporters for K.

Passive potassium transport in LK sheep red cells. Modification by N-ethyl maleimide.

Passive K transport, as modified by N-ethyl maleimide (NEM), was studied in erythrocytes of the low-K (LK) phenotype of sheep. Brief (5-min) treatment with NEM at less than 0.5 mM caused inhibition of passive K influx; NEM at concentrations greater than 0.5 mM caused stimulation of K influx. NEM had similar effects on K efflux. The treatments with NEM did not affect cell volumes (passive K transport in LK cells is sensitive to changes in cell volume). The stimulation of K transport by high [NEM] was also not a consequence of an effect on the metabolic state of the cells. Passive K transport in LK cells is dependent on Cl (it is inhibited in Cl-free media; it may be K/Cl cotransport). NEM had no effect on K influx in Cl-free (NO3-substituted) media. Pretreatment of the cells with anti-L antiserum (L antigen is found on LK cells and not on HK cells) prevented stimulation of K influx by NEM, but did not prevent inhibition. Therefore, NEM modifies the Cl-dependent K transport pathway at two separate sites, a low-affinity site, at which it stimulates, and a high-affinity site, at which it inhibits. Anti-L antibody prevents NEM's action, but only at the low-affinity site.

Effect of alcohol consumption on state anxiety changes in male and female nonalcoholics.

Ten male and 10 female nonalcoholic college students were given drinks having alcohol levels of 0, 0.5, 0.8, and 1.2 g/kg. They were then given four complex psychomotor tests, immediately before and after which they were given the Spielberger State Anxiety Inventory, and asked to rate their performance on a five-point scale. Mean anxiety change scores were -.90, .75, 4.75, and 5.55 for the four alcohol doses, respectively. There was no significant correlation between anxiety change and actual performance on the visual vigilance task, but for males there was a significant correlation between anxiety change and perceived level of impairment.

Development of an organic affective syndrome during a hyperbaric diving experiment.

The authors describe the clinical and pharmacologic management of a patient who developed an organic affective syndrome during a simulated deep-diving experiment. The physiological complexities of deep-diving research are reviewed, as well as the neuropsychiatric symptoms of the high pressure nervous syndrome.

Neuropsychological importance of subcortical white matter hyperintensity.

Subcortical hyperintensity on magnetic resonance imaging is a common incidental finding in healthy elderly subjects. The relationship of such changes to cognitive functioning remains unclear, however, because only a small number of studies have examined this issue with conflicting results. We therefore assessed 66 healthy adult volunteers (mean [+/- SD] age, 61.8 +/- 15.8 years) with magnetic resonance imaging scans rated for subcortical hyperintensity, and with two neuropsychological instruments selected a priori on the basis of previous reports in the literature. Findings were highly significant for both the Benton Facial Recognition Test and the Wechsler Adult Intelligence Scale-Revised Digit Symbol. However, in both cases, the majority of variance was accounted for by age and educational level. Effects of subcortical hyperintensity were not significant. We conclude that subcortical hyperintensity in healthy adults does not relate to cognitive functioning, at least with these two instruments.

Neologistic speech automatisms during complex partial seizures.

There are no documented cases of seizures causing reiterative neologistic speech automatisms. We report an 18-year-old right-handed woman with stereotypic ictal speech automatisms characterized by phonemic jargon and reiterative neologisms. Video-EEG during the reiterative neologisms demonstrated rhythmic delta activity, which was most prominent in the left posterior temporal region. At surgery, there was an arteriovenous malformation impinging on the left supramarginal gyrus and the posterior portion of the superior temporal gyrus. Though intelligible speech automatisms can result from seizure foci in either hemisphere, neologistic speech automatisms may implicate a focus in the language-dominant hemisphere.

Prospective study of neuropsychologic testing and quality-of-life assessment of adults with primary malignant brain tumors.

PURPOSE: To identify the characteristics of adult patients with newly diagnosed primary brain tumors associated with identifiable deficits in neuropsychologic function to target interventions to improve function and quality of life (QOL). MATERIALS AND METHODS: Adult patients with newly diagnosed primary brain tumors and their caregivers were enrolled and underwent a battery of standardized neuropsychologic tests, allowing for qualitative and quantitative assessment and sensitive to the effects of the brain tumor, QOL, or caregiver stress. RESULTS: We enrolled 68 patients with no prior radiotherapy. Patients with left hemisphere tumors reported significantly more memory problems and depressive symptoms. They also exhibited poorer attention and were more distractible, with poorer verbal fluency and poorer verbal learning. Patients with glioblastoma multiforme demonstrated poorer psychomotor speed and visual tracking than patients with non-glioblastoma multiforme histologic features. Patients and caregivers perceived QOL in a similar fashion, with significant correlation between patient and caregiver on hope testing and general QOL on the Linear Analog Self-Assessment Scale. CONCLUSIONS: Patients with left hemisphere tumors and glioblastoma multiforme histologic features demonstrated testable differences in neuropsychologic function and QOL that may be amenable to improvement with medical therapy or tailored rehabilitation programs. Caregiver assessments can predict patient QOL, which may be useful in patients with declining status.

Predicting intellectual level from the Mini-Mental State Examination.

The Mini-Mental State Examination and the WAIS-R were administered to 105 patients in the early stages of Alzheimer's disease. MMSE scores correlated 0.83 with full scale IQ, which indicates that the MMSE may be a reasonable alternative measure of overall intellectual functioning in Alzheimer patients, for whom more extensive testing is impractical or clinically inappropriate. The prediction formula is presented, along with a prediction table. Folstein and McHugh report that, as the WAIS Performance IQ falls below 100 in demented patients, that there is a concomitant decline in the MMSE below 24 points. Data from our laboratory further support what some clinicians have long suggested, ie, that in those cases where only the mental status examination can be given, this short test can provide a reasonably valid and reliable prediction of the patient's IQ score.

Efficacy and side effects of flurazepam and a combination of amobarbital and secobarbital in insomniac patients.

Flurazepam, 30 mg, was not more effective in inducing sleep than placebo. Barbiturates (100 mg amobarbital plus 100 mg secobarbital) were more effective in inducing and maintaining sleep than flurazepam or placebo. Contrary to work conducted in the sleep laboratory, the barbiturate hypnotics were still effective on the 14th night. Insomniacs performed poorly on psychomotor tests, but as a group they did not show statistically significant psychomotor impairment after the use of the hypnotics.

Effects of alcohol and flunitrazepam on mood and performance in healthy young men.

Alcohol and flunitrazepam did not have any pharmacokinetic interactions when ingested 30 minutes apart at night. Flunitrazepam, 2.0 mg, but not 0.8 Gm/kg alcohol had a strong deleterious effect on performance shortly after ingestion. The combination of flunitrazepam and alcohol impaired tracking in a divided attention task the following morning.

The effects of traumatic brain injuries on information processing.

Many individuals experience memory impairment subsequent to traumatic brain injuries (TBI). These memory deficits may result from general impairment of information processing rather than damage to memory critical neurological systems. The investigators examined learning time and recall errors for easy and hard word pairs in a distraction and no-distraction condition to examine learning patterns. Although results indicated that individuals with and without TBI generally showed the same learning and retrieval patterns, individuals with TBI did so in an accentuated manner. This suggests that attentional deficits associated with TBI are not responsible for subsequent memory deficits.

Information processing time adds useful information to traditional recall measures.

Clinical work and research activity using memory tests typically use measures of recall. While these measures are useful, they may restrict the nature of memory assessments. A memory test was developed to record encoding and recall times. Analyses were then conducted to determine whether these encoding and recall times related to recall performance. Results indicated that encoding time and recall time related significantly to recall performance. Data also revealed that while the strength of the relationship between encoding time and recall errors generally remained constant, the relationship between recall time and recall errors decreased as task demands increased.

The effect of ECT on the perception of emotion in depressed patients.

35 psychiatric inpatients with diagnosed with unipolar or bipolar depression were given tests of memory, depression, and affective aprosody prior to the initiation of pulse unilateral nondominant ECT. Following ECT treatment, patients were given the same battery of tests using alternate forms of the same tests. The results of this study showed significant treatment effects in all three dependent variables without significant interaction between variables. The implications of these findings were discussed.

Effects of alcohol on psychomotor performance of men and women.

The effects of alcohol on performance were investigated in 10 men and 10 women. On 4 psychomotor tasks minor gender-related effects of alcohol were found.

Severe classroom behavior problems: teachers or counsellors.

This experiment was designed to determine the relative effectiveness of teacher and counselling approaches in the reduction of disruptive or inappropriate classroom behavior. Inappropriate classroom behavior frequencies of 12 academically low achieving, seventh-grade, black male students, with a reported high rate of inappropriate classroom behavior, were recorded. Three groups, with nearly equal mean inappropriate behaviors, were randomly assigned to one of three treatment conditions: behavioral counselling, client-centered counselling, or no counselling. Each counselling group received fifteen 30-minute counselling sessions, at a rate of two to three times a week. In addition to counselling, all students subsequently received teacher approval within the classroom. Results indicated that the teacher was able to reduce inappropriate behavior more than any counselling group. There were also indications that behavioral counselling, but not client-centered counselling, was moderately helpful in reducing inappropriate classroom behavior.

Psychological measurement of memory deficits in dialysis patients.

In light of recent research on "dialysis dementia," two questions were raised: (1) Is such dementia an all-or-none phenomenon or is it distributed in severity throughout the population of dialysis patients? (2) Is the dementia related to the uremia itself or to some aspect of dialysis? Memory decline was used as the operational definition of dementia. The Russell revision of the Wechsler Memory Scale was used to measure short- and long-term semantic and figural memory. Results suggested that both semantic and figural memory disturbances were distributed in varying degrees throughout the population of dialysis patients (n = 28). Further findings suggested that figural memory functioning was negatively correlated with the number of dialysis sessions and with the amount of time elapsed since the first dialysis session. Suggestions are made for further research and clinical considerations.

Effects of ethanol and psychomotor tests on state anxiety: interaction with menstrual cycle in women.

10 non-alcoholic women (ages 20 to 25 yr.) were administered drinks containing ethanol 0.0, 0.5, 0.8, and 1.2 g/kg. They then performed four complex psychomotor tasks. Immediately prior to drinking and after completing the tasks they were given the Spielberger State-Anxiety Inventory. Women were tested both during follicular and the luteal phases of their menstrual cycle. A significant positive correlation was found between increments in anxiety scores and blood ethanol levels in the luteal but not in the follicular phase.