Genetic relationships between clinical isolates of Streptococcus pneumoniae, Streptococcus oralis, and Streptococcus mitis: characterization of "Atypical" pneumococci and organisms allied to S. mitis harboring S. pneumoniae virulence factor-encoding genes.

The oral streptococcal group (mitis phylogenetic group) currently consists of nine recognized species, although the group has been traditionally difficult to classify, with frequent changes in nomenclature over the years. The pneumococcus (Streptococcus pneumoniae), an important human pathogen, is traditionally distinguished from the most closely related oral streptococcal species Streptococcus mitis and Streptococcus oralis on the basis of three differentiating characteristics: optochin susceptibility, bile solubility, and agglutination with antipneumococcal polysaccharide capsule antibodies. However, there are many reports in the literature of pneumococci lacking one or more of these defining characteristics. Sometimes called "atypical" pneumococci, these isolates can be the source of considerable confusion in the clinical laboratory. Little is known to date about the genetic relationships of such organisms with classical S. pneumoniae isolates. Here we describe these relationships based on sequence analysis of housekeeping genes in comparison with previously characterized isolates of S. pneumoniae, S. mitis, and S. oralis. While most pneumococci were found to represent a closely related group these studies identified a subgroup of atypical pneumococcal isolates (bile insoluble and/or "acapsular") distinct from, though most closely related to, the "typical" pneumococcal isolates. However, a large proportion of isolates, found to be atypical on the basis of capsule reaction alone, did group with typical pneumococci, suggesting that they have either lost capsule production or represent as-yet-unrecognized capsular types. In contrast to typical S. pneumoniae, isolates phenotypically identified as S. mitis and S. oralis, which included isolates previously characterized in taxonomic studies, were genetically diverse. While most of the S. oralis isolates did fall into a well-separated group, S. mitis isolates did not cluster into a well-separated group. During the course of these studies we also identified a number of potentially important pathogenic isolates, which were frequently associated with respiratory disease, that phenotypically and genetically are most closely related to S. mitis but which harbor genes encoding the virulence determinants pneumolysin and autolysin classically associated with S. pneumoniae.

Molecular characterization of equine isolates of Streptococcus pneumoniae: natural disruption of genes encoding the virulence factors pneumolysin and autolysin.

Although often considered a strict human pathogen, Streptococcus pneumoniae has been reported to infect and cause pneumonia in horses, although the pathology appears restricted compared to that of human infections. Here we report on the molecular characterization of a group of S. pneumoniae isolates obtained from horses in England and Ireland. Despite being obtained from geographically distinct locations, the isolates were found to represent a tight clonal group, virtually identical to each other but genetically distinguishable from more than 120 divergent isolates of human S. pneumoniae. A comprehensive analysis of known pneumococcal virulence determinants was undertaken in an attempt to understand the pathogenicity of equine pneumococci. Surprisingly, equine isolates appear to lack activities associated with both the hemolytic cytotoxin pneumolysin, often considered a major virulence factor of pneumococci, and the major autolysin gene lytA, also considered an important virulence factor. In support of phenotypic data, molecular studies demonstrated a deletion of parts of the coding sequences of both lytA and ply genes in equine pneumococci. The implications of these findings for the evolution and pathogenicity of equine S. pneumoniae are discussed.

Incidence, prevalence, and outcomes of end-stage renal disease patients placed in nursing homes.

We prospectively surveyed the 156 dialysis centers in Network 5 (MD, VA, WV, DC) for end-stage renal disease (ESRD) patients admitted to or begun on dialysis in nursing homes during a 21-month period (April 1, 1990 to December 31, 1991). In addition to this incidence data, information on patient demographics, social characteristics, pre-existent illnesses, and functional capacity (measured by activity of daily living [ADL] scores) was obtained. One hundred thirty-two centers (close to 90% of Network 5's approximately 9,000 patients) responded to the survey. Outcome data were gathered throughout the 21-month period and the subsequent 5 months. Seventy-three centers dialyzed 228 such patients during the 18-month period. Five centers that were located in the same building as a nursing home cared for 67 patients. The 228 patients, aged 17 to 101 years, were older (65.50 years +/- 14.2 [SD] v 53.7 +/- 16.4 years), and disproportionately female (62.2% v 48.3%), white (46.5% v 37.4%), and diabetic (57.9% v 29%) compared with the general network ESRD population (P < 0.05). On admission to the nursing home 47% of patients had organic heart disease, 35% had an organic brain syndrome, 22% had cerebrovascular diseases, 19% had amputations, and 18% were blind. The mean admission ADL score was 8.1 +/- 5.2 (maximum function, 18) and the patients did not differ regarding age, sex, race, or diabetes. Forty-three percent of patients lived alone or in sheltered housing before being placed in the nursing home.(ABSTRACT TRUNCATED AT 250 WORDS)

The perception of emotion by schizophrenic patients.

Studies which have examined the perception of emotion by schizophrenic patients have produced conflicting results, an outcome which may, in part, be due to difficulties in presenting a realistic portrayal of emotion. This study exposed 32 schizophrenic patients in remission and ten controls to five videotaped scenes of emotional situations played by actors. The schizophrenic patients were divided into three groups, namely those living with high-EE relatives, those living with low-EE relatives and those living alone, in order to test the hypothesis that patients in a high-EE environment are less able to identify emotionally charged situations. Measures of electrodermal activity and self-ratings of tension were recorded concomitantly. The schizophrenic patients in all groups were as adept at identifying emotions as were the controls. There was no difference between the groups in electrodermal activity and subjective tension for all video scenes, except for the one which portrayed the only pleasant interaction; the high-EE group was significantly more aroused on both measures, which were independent of each other.

The King's Cross fire. Part 2: The psychological injuries.

This paper describes the experiences of six people who received severe burns in the King's Cross Underground Station fire of 1987. They all developed post-traumatic stress disorder to varying levels of intensity and the problems of psychological intervention as they related to the patients' different mental defence mechanisms are outlined.

Use of continuous ambulatory peritoneal dialysis in a nursing home: patient characteristics, technique success, and survival predictors.

Forty-four end-stage renal disease (ESRD) patients admitted to a nursing home were treated with continuous ambulatory peritoneal dialysis (CAPD). The technical feasibility of using CAPD in this setting was demonstrated by an acceptable peritonitis rate (1.3 episodes per patient-year), acute hospitalization rate (18.5 days per patient-year), and only two technique failures. However, 6-month and 12-month survival rates were 53% and 29%, respectively. Survival analysis using the Cox model showed that patients with better functional status on admission measured by activity of daily living scores and who had previously been in an outpatient dialysis program before admission survived longer and were more often discharged.

A controlled trial of social intervention in the families of schizophrenic patients: two year follow-up.

The two-year follow-up results are reported of a trial of social intervention in families of schizophrenic patients in high social contact with high-expressed emotion (EE) relatives. For those patients who remained on antipsychotic medication throughout the two years, the social intervention significantly reduced the relapse rate. In those experimental families where relatives' EE and/or face-to-face contact was lowered, the relapse rate was 14% compared with 78% for control patients on regular medication (P = 0.02).

Psychophysiological responses of schizophrenic patients to high and low expressed emotion relatives: a follow-up study.

Measurements of skin conductance response frequencies (SCRf) were obtained from 30 acutely ill schizophrenic patients during a standardised videotaped interview, conducted with the patient's key relative present. Significant differences in SCRf's were demonstrated between patients whose relatives had high and low Expressed Emotion (EE) respectively. Patients at high risk of relapse were allocated either to a control or an experimental group, the latter being offered a number of social interventions in order to reduce the relative's EE and/or contact with the patient. Follow-up measurements were obtained on 19 patients nine months after discharge. Although social intervention was highly successful in reducing relapse rates, its effects did not appear to be directly mediated via SCRf, which was found to be independently related to relapse.

Psychosocial relevance and benefit of neuroleptic maintenance: experience in the United Kingdom.

The benefits of psychosocial intervention were studied in patients on maintenance neuroleptics who live in high face-to-face contact with relatives who have high levels of expressed emotion. This group is at high risk of relapse when maintained on neuroleptics without social intervention. Relatives of patients in the experimental group received three types of intervention: an educational program, a relatives' group, and family therapy. The goal of intervention was to reduce face-to-face contact and/or relatives' levels of expressed emotion. The results at 9-month and 2-year follow up indicate the benefits of psychosocial intervention, while pointing out the danger in discontinuing maintenance neuroleptics for patients who live in stressful family environments.

A pain microcomputer system for clinical and laboratory investigation.

This report describes the design and use of a mobile "Pain Microcomputer System" (PMS). As a mobile clinical and laboratory research tool the PMS integrates four functions: (1) psychophysical measurement of behavioral pain responses; (2) psychophysiologic recording, including brain evoked potentials, cortical power spectrum analysis, EKG and EMG; (3) data acquisition, analysis and display; (4) peripheral communications via modem allows interaction with larger computers for more complex data analyses, extensive graphics, etc. A word processor disk facilitates writing of scientific and clinical reports. Present and future capabilities of the system for comprehensive pain research and patient care are discussed.

Characteristics of expressed emotion: its relationship to speech and looking in schizophrenic patients and their relatives.

The measure expressed emotion (EE) is an established indicator of characteristics in the relatives of schizophrenic patients which predict relapse. Despite this, little is known of its construct validity except that schizophrenic patients are less calm in the presence of high EE than low EE relatives. There is also tentative evidence that schizophrenic patients show heightened avoidance responses to aversive social stimuli. It was therefore hypothesized that acutely ill schizophrenic patients would show social behaviours characteristic of avoidance in interaction with high but not low EE relatives. This hypothesis was not confirmed as no patient difference was found, but there were differences in the behaviour of high and low EE relatives. High EE relatives spend more interview time talking and less in looking at the patients. Low EE relatives were more prepared to be silent. This is consistent with the general tendency of high EE relatives to be socially intrusive and low EE relatives to be supportive to schizophrenic patients.

Life events, relatives' expressed emotion and maintenance neuroleptics in schizophrenic relapse.

Data from two studies, one naturalistic and the other a controlled trial, were analysed to clarify the relationships between independent life events. Expressed Emotion of a key relative, maintenance neuroleptics and the relapse of schizophrenia. It was found that patients in the community who are unprotected by medication are vulnerable either to acute stress in the form of life events or to chronic stress in the form of living with a high Expressed Emotion relative. Patients on regular medication are protected against one or other stress, but are very likely to relapse if the two forms of stress occur together. A model of schizophrenic susceptibility to environmental stress is constructed to incorporate these observations.

The relationship between auditory hallucinations and spontaneous fluctuations of skin conductance in schizophrenia.

A sample was collected of schizophrenic patients exhibiting nonverbal signs of intermittent auditory hallucinations. A video-tape record was made for each of a session, during which the patient's skin conductance was monitored. Independent raters achieved reasonable agreement on the onset of periods of hallucinatory activity, as judged from non-verbal signs. The skin conductance tracing was scored independently for spontaneous fluctuations. In the 10 patients with satisfactory records the onset of hallucinatory periods was significantly (P less than 0.01) associated with a rise in the spontaneous fluctuation rate.

Measurement of sweating rate with capacitance sensors.

A new forced-evaporation type skin capsule for measuring local sweat gland activity in humans is described and details of its construction and problems of calibration are presented. The capsule is self-contained, portable, and inexpensive making it well suited for use in arrays to make multiple simultaneous determinations on adjacent skin areas. Sweat is evaporated from the skin surface by a stream of dry nitrogen gas; subsequent changes in capsule relative humidity and temperature are measured by a commercially available thin-film capacitance sensor and a solid-state current regulating device, respectively. These changes are measured within the capsule itself so no external water vapor analyzer is needed. Data acquisition and evaporation rate calculations are handled by an on-line microcomputer.

A controlled trial of social intervention in the families of schizophrenic patients.

A study is reported of a controlled trial of social intervention in the families of schizophrenic patients at high risk of relapse. The patients were selected for being in high contact with high Expressed Emotion relatives. All patients were maintained on neuroleptic drugs. One half of the 24 families were randomly assigned to routine out-patient care, while the other half received a package of social interventions. This comprised a programme of education about schizophrenia, a group for the relatives, and family sessions for relatives and patients. The relapse rate in the control group was 50 per cent compared with nine per cent in the experimental group (P = 0.04). The stated aims of the therapeutic interventions were achieved in 73 per cent of experimental families. In these families, no patient relapsed. The results provide evidence for the causal role of relatives' expressed emotion (EE) in schizophrenic relapse, as well as for the therapeutic effectiveness of social intervention combined with drug treatment.

Psychophysiological responses of schizophrenic patients to high and low expressed emotion relatives.

Measurements of spontaneous fluctuations in skin conductance in 20 acutely ill schizophrenic patients were made in a video-tape studio. Recordings were made initially with the patient talking to an interviewer, then during a video-taped interview conducted with the patient's key relative. The Expressed Emotion (EE) of the patient's key relative had been measured previously. Significant differences in the type of spontaneous fluctuation activity between patients who had low EE and high EE relatives were demonstrated when the relative was present, but not when the relative was absent. The findings were not related to phenothiazine medication.

Videotapes in psychiatry: their use in teaching observation techniques.

In order to assess the effectiveness of videotapes in teaching mental state examination, two groups of medical students, one who had received videotape teaching and one not exposed to videotapes, are compared in their ability to observe accurately the mental state during a live interview. Accuracy of observation was assessed by obtaining a measure of the students' ability to shift from an incorrect opinion about a patient to a more accurate assessment following the live interview. Students who had received videotape teaching were able to make more accurate judgements than those who had not. This ability was not related to certain personality attitudes measured, nor to an ability to detect subjective elements in the interview, nor is it reflected in their examination results. The only significant variable found to influence this ability was whether or not the student had received videotape teaching.