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Biomedical subjects

D Bolton

Publications and source records attributed to D Bolton.

35 records · Page 2Linked to original sources
PubMed1994

Percutaneous nephrolithotomy in the elderly.

OBJECTIVES: To evaluate the success and morbidity of percutaneous nephrolithotomy (PNL) performed in patients aged 65 years and older. METHODS: A retrospective review of 42 PNLs performed on 33 patients aged 65 years and older was compared with a cohort of 160 PNLs performed on younger patients over the same time period. RESULTS: The presence of complete staghorn calculi (17 of 36 renal units [47%] versus 88 of 160 renal units [55%], p = 0.46) and average stone size (3.8 cm versus 4.3 cm, p = 0.2) were similar for the 2 groups. Eighty-two percent of patients (27 of 33) were stone-free or left with fragments < 5 mm at 3 months after surgery. Elderly patients had a higher transfusion rate after PNL despite similar preoperative hemoglobin levels (11 of 42 PNLs [26%] versus 22 of 160 PNLs [14%], p < 0.01). Serious complications were infrequent and there were no deaths. CONCLUSIONS: Percutaneous nephrolithotomy is a safe and effective therapy for elderly patients with complex stone disease; however, awareness of an apparent increased requirement for blood transfusion is warranted.

Age Factors↗
PubMed1994

Clinical correlates of the gross, radiographic, and histologic features of urinary matrix calculi.

We present five patients with urinary matrix calculi, which, in contrast to the normally brittle calcigerous calculi, are soft, pliable, and amorphous. Common clinical features include a history of calcigerous stone disease, renal surgery, urinary obstruction or stasis, and chronic infection with Proteus species or coliforms. The diagnosis is usually made at surgery, but certain preoperative radiographic findings may be suggestive. Matrix calculi are radiolucent on plain abdominal films, although their appearance on nonenhanced CT scans is similar to that of calcigerous calculi despite their small mineral content. Extracorporeal shockwave lithotripsy is ineffective; open or percutaneous techniques are necessary. Histologic inspection reveals laminar concentric rings of organized matrix with an orderly, layered deposition of minerals. Histochemical investigation can provide insight into the possible sequence of events in normal calculogenesis. The successful management of urinary matrix calculi depends on a high index of suspicion and a thorough knowledge of their clinicopathologic features.

Adult↗
PubMed1994

Randomized study of the effect of midnight removal of urinary catheters.

This study shows that removal of urinary catheters at midnight has several advantages over removal at 6 AM. The midnight group had a significantly greater initial voided volume and a longer time to first void than the equivalent 6 AM group. Advantages to midnight catheter removal also exist for nursing staff. Midnight tends to be less busy on the nursing unit compared with 6 AM, thus making it a preferable time for performance of routine tasks. Catheter removal at midnight also allows for convenient observation of patient voiding and assessment earlier in the day. This means that any necessary intervention can take place during working hours when more staff are on duty. There is also the potential for earlier discharge, with economic benefits related to shorter bed stay and more efficient discharge planning. We believe midnight catheter removal offers considerable benefits over the traditional 6 AM time on both general and urology units.

Female↗
PubMed1991

The neurology of obsessional slowness.

Seventeen of 59 patients admitted to hospital for treatment of Obsessive-Compulsive Disorder (OCD) were found to have significant slowness, mainly due to difficulty in initiating goal-directed action and suppressing intrusive and perseverative behaviour. In this subgroup subtle neurological abnormalities were found more frequently than in healthy controls and included loss of motor fluency, hesitancy of initiation of limb movements, speech and gait abnormalities, cogwheel rigidity, complex repetitive movements and tics. Difficulties in cognitive set-shifting and complex spatial-and-shifting abilities were found on neuropsychological testing, but no correlation was found between these disturbances and either the degree of obsessionality or the severity of motor dysfunction. These results suggest that patients with obsessional slowness may have a dysfunction in the frontal-basal-ganglia loop system.

Adolescent↗
PubMed1989

Deficit in cognitive shifting ability in patients with obsessive-compulsive disorder.

Reports on cognitive test deficits in patients with obsessive-compulsive disorders and interpretations of the underlying dysfunction have been conflicting. In the present study, 15 obsessive-compulsive patients were compared with 15 matched normal controls on three types of test sensitive to: spatial ability, ability to shift cognitive set, and combinations of both. Performance deficits as compared with controls were shown in Block Design, the Short Wisconsin Card Sort, the Word Fluency Test, and on the Money Road Map Test. No deficits were present on a number of other measures. The pattern of results is interpreted partly as revealing deficits in ability to shift cognitive set, more particularly with nonverbal material.

Adult↗
PubMed1986

A prospective analysis of 1,400 pulmonary artery catheterizations in patients undergoing cardiac surgery.

During 1983 and 1984, 1305 patients underwent 1,400 pulmonary artery (PA) catheterizations. Successful placement was achieved in 1397 (99.6%) of 1,403 attempts. The catheters were inserted via the right internal jugular vein on 1364 occasions. The median duration of monitoring was 28 h with a range from 3 to 220 h. Central venous puncture complications included carotid artery puncture in 67 instances (4.8%) and pneumothorax in one patient. Insertion of the catheters was associated with supraventricular arrhythmias on 11 occasions, ventricular arrhythmias on 930 (66.4%), right bundle branch block on two and a total heart block on one occasion. Eighteen (2.3%) of the 794 cultured catheter tips were positive. An in situ time of more than 72 h was associated with a significantly higher percentage (7.2%) of positive tip cultures compared with an in situ time of less than 72 h (P less than 0.01). Repeated PA catheterization was not associated with significantly more complications than the initial catheterization. The results show that monitoring with a PA catheter in cardiac surgical patients is associated with a low incidence of morbidity.

Arrhythmias, Cardiac↗
PubMed1985

An investigation of two self-report measures of obsessional phenomena in obsessive-compulsive adolescents: research note.

A number of studies have recently demonstrated the clinical utility of objective self-report inventories in the assessment of obsessive-compulsive disorders in adults. To date, the usefulness of these instruments has not been demonstrated with obsessive-compulsive adolescents. In the present study the Leyton Obsessional Inventory and the Maudsley Obsessional-Compulsive Inventory were administered to 11 obsessive-compulsive adolescents and a group of 10 anxious non-obsessional patients. The obsessional adolescents scored significantly higher than the controls on the Maudsley total score and checking factors alone. Possible explanations of the results are discussed.

Adolescent↗
PubMed1985

Obsessive-compulsive adolescents and their parents: a psychometric study.

The present study examined obsessive personality traits and achievement expectations of parents with an obsessive-compulsive adolescent. The Leyton Obsessional Inventory (LOI) and rating scales of occupational and educational aspirations and expectations were administered to both parents and the adolescent of 12 families with an obsessional adolescent and 10 families having an anxious, nonobsessional son or daughter. The parents' LOI scores were similar in the two groups, though higher than normal adults on the trait and resistance scales. The obsessional adolescents perceived their parents to hold significantly higher career demands for them than the anxious adolescents.

Achievement↗
PubMed1984

Obsessive-compulsive neurosis with conduct disorder in adolescence: a report of two cases.

Two adolescents are described presenting with obsessive-compulsive neurosis and conduct disorder. The presence of conduct disorder is in marked contrast to the compliance and over-control characteristic of obsessionality, and was found to give rise to great difficulties in instigating and carrying through a programme of response-prevention for the obsessive-compulsive symptoms.

Adolescent↗
PubMed1984

Opinions on the role of the internship in psychiatric postgraduate education.

Presently in Canada the value of the straight internship in psychiatry and the need for a mandatory rotation in psychiatry during a rotating internship are sources of active debate between the licensing bodies and psychiatric programs and organizations. The importance of the internship as it pertains to the total psychiatric education process has been discussed in a number of research articles from the United States. The conclusions from these studies range from recommendations that rotating internships be discontinued because they may cause empathic blunting among trainees, to strong endorsements of its necessity. The present study examined residents' and residency directors' views of the types of internships in Canada. One hundred and ninety-nine residents and thirteen residency directors completed a questionnaire in 1980. The majority of residents (74.3%) and residency directors (77%) felt that the rotating-mixed internship should be a requirement prior to taking post-graduate training in psychiatry. Most also felt that this type of internship should contain a mandatory one to two months psychiatry rotation. Opinions on the value of the straight internship in psychiatry were mixed for both residents and residency directors. Statistical analyses were carried out comparing the opinions of residents having had a rotating internship versus those having had a straight internship: foreign medical graduates (FMG's) versus Canadian medical graduates (CMG's); and male versus female. As would be expected, the residents who had previously completed a straight internship favoured this type of internship and were more critical of the rotating type.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗
PubMed1984

Chromosome aberrations induced in human lymphocytes by D-T neutrons.

Unstable chromosome aberrations induced by in vitro irradiation with D-T neutrons have been analyzed in human blood lymphocytes. With respect to 250 kVp X rays a maximum limiting RBE at low doses of 4.1 was obtained for dicentric aberrations. Using aberrations as markers in mixed cultures of irradiated and unirradiated cells permits an assessment of interphase death plus mitotic delay. The low-dose RBE for this effect is 2.5. Assuming all unstable aberrations observed at metaphase would lead to cell death by nondisjunction allows an assessment of mitotic death. The low-dose RBE for this effect is 4.5. The data are compared with similar work obtained earlier with 242Cm alpha particles. The application of the present work to cytogenetic assessment of dose after accidental exposure to D-T neutrons is discussed.

Cell Division↗
PubMed1983

The treatment of obsessive-compulsive disorder in adolescence. A report of fifteen cases.

The treatment of 15 adolescents with obsessive-compulsive disorder is described. Treatment was in most cases primarily behavioural (response-prevention), with the family involved in the therapy. Other components of treatment which were used in some cases are also described: medication, psychotherapy, and 'milieu' therapy. Outcome after treatment was generally good, with symptoms in most cases being relieved entirely or reduced to a mildly incapacitating level. Treatment gains in most cases were maintained at follow-up. Obstacles to treatment are noted, and recommendations are made as to the management of the disorder in adolescence.

Adolescent↗
PubMed1975

The relationship between chromosome aberrations and low LET radiation dose to human lymphocytes.

In vitro dose-response curves of unstable chromosome aberrations in human lymphocytes have been obtained for 250 kV X-rays and cobalt-60gamma-radiation. The aberration yields have been fitted to the quadratic function Y = alphaD +betaD2, which is consistent with the single-track and two-track model for aberration formation. The values of the coefficients alpha and beta support the hypothesis that the dose-rate effect is limited to the D2 term. The main difference between the coefficients for X- and gamma-radiation is in the alpha values, indicating that X-rays are slightly more efficient, at lower doses, in producing two lesions with a single ionizing track. The lower limits of dose estimate, with 500 cells analysed, are 4 rad for X-rays and 10 rad gamma-radiation. Further evidence is presented confirming that, for cytogenetic dosimetry, in vitro dose-response curves should be prepared by irradiating whole blood maintained at 37 degrees C and prior to PHA stimulation. Curves were plotted showing the variation of the number of cells without aberrations with radiation dose and the shape of these curves were compared with those from human cell survival experiments.

Adult↗
PubMedDate not supplied

The nature of the unconventional slow infection agents remains a puzzle.

Unconventional slow infections are progressive transmissible degenerative disorders of the central nervous system. The human diseases belonging to this group are Creutzfeld-Jakob disease, kuru, and Gerstmann-Straussler syndrome. Scrapie, transmissible mink encephalopathy, chronic wasting disease of mule deer and elk, and the recently discovered bovine spongiform encephalopathy are similar diseases found in animals. Unusual characteristics of the unconventional slow infections clearly distinguish these disorders from conventional infections. These include: unusually long incubation periods (from months to years); progressive CNS degeneration with characteristic histopathological lesions; the lack of an immune or inflammatory response; unconventional biological and physical properties of the etiologic agents. There has been considerable controversy concerning the nature of the causative agent. The 3 main hypotheses, virus, virino, and modified host protein, are reviewed relative to their ability to explain the properties of the agent and the unusual characteristics of the disease process. The discovery of an abnormal structure, termed scrapie associated fibrils (SAF) and an abnormally modified 33-37 kDa host-encoded glycoprotein unique to unconventional slow infections opened new areas of intense interest and investigation. SAF are abnormal filamentous structures which copurify with infectivity and possess characteristics of "amyloids." The major component of SAF is the host-encoded scrapie-specific protease resistant glyco-protein. Considerable data has accumulated on the biochemistry, immunology and molecular biology of this host coded scrapie protein. The relationship of SAF and the scrapie-specific protein to the infectious agent is discussed in the context of each of the "nature of the agent" hypotheses.

Animals↗