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Biomedical subjects

B Little

Publications and source records attributed to B Little.

At least 19 recordsLinked to original sources
PubMed2003

PSA testing in general practice.

A questionnaire was sent to 400 general practitioners (GPs), concerning prostate-specific antigen (PSA) screening. Regarding the indications for PSA testing, 80% of GPs test men with urinary tract symptoms, 65% test men with a positive family history, 62% test on patient request, and 21% test men with unrelated symptoms. When PSA is measured, 91% of GPs inform their patient, and 71% discuss the significance of an abnormal result. The mean age range for PSA testing was from 50 years, without an upper age limit. The mode PSA threshold for referral was 6.6 ng/ml. De facto PSA screening appears to be widely practised.

Adult↗
PubMed2003

Use of nephrostomy tubes in ureteric obstruction from incurable malignancy.

Malignancy may produce ureteric obstruction. This obstruction may be relieved by inserting a nephrostomy tube. All 31 cases of malignant ureteric obstruction from a single institution were retrospectively analysed. The commonest indications for nephrostomy tube insertion were renal failure (87%) and flank pain with hydronephrosis (13%). The mean serum creatinine levels pre and post insertion were 481 and 170 micromol/l, representing significant improvement (p<0.01). The complication rate was 13%, relating to tube blockage or dislodgement. Survival of patients was significantly worse if their malignancy was not resectable or suitable for chemotherapy (p=0.01). However, incurable patients still survived for a mean of 232 days, and although 46% of this time was spent as an inpatient, it did not differ significantly from the inpatient rate of curable patients (31%, p=0.1). Nephrostomy tube insertion should be considered for all palliative cases of malignant ureteric obstruction.

Aged↗
PubMed2001

Mineralogical biosignatures and the search for life on Mars.

If life ever existed, or still exists, on Mars, its record is likely to be found in minerals formed by, or in association with, microorganisms. An important concept regarding interpretation of the mineralogical record for evidence of life is that, broadly defined, life perturbs disequilibria that arise due to kinetic barriers and can impart unexpected structure to an abiotic system. Many features of minerals and mineral assemblages may serve as biosignatures even if life does not have a familiar terrestrial chemical basis. Biological impacts on minerals and mineral assemblages may be direct or indirect. Crystalline or amorphous biominerals, an important category of mineralogical biosignatures, precipitate under direct cellular control as part of the life cycle of the organism (shells, tests, phytoliths) or indirectly when cell surface layers provide sites for heterogeneous nucleation. Biominerals also form indirectly as by-products of metabolism due to changing mineral solubility. Mineralogical biosignatures include distinctive mineral surface structures or chemistry that arise when dissolution and/or crystal growth kinetics are influenced by metabolic by-products. Mineral assemblages themselves may be diagnostic of the prior activity of organisms where barriers to precipitation or dissolution of specific phases have been overcome. Critical to resolving the question of whether life exists, or existed, on Mars is knowing how to distinguish biologically induced structure and organization patterns from inorganic phenomena and inorganic self-organization. This task assumes special significance when it is acknowledged that the majority of, and perhaps the only, material to be returned from Mars will be mineralogical.

Databases, Factual↗
PubMed2001

Electrocardiogram and rhythm strip interpretation by final year medical students.

The pre-registration house officers (PRHO) is often called upon to interpret electrocardiograms ECG. We invited final-year medical students who had successfully completed their written final examinations, to interpret three rhythm-strip tracings, and three 12-lead ECG tracings. The rhythm-strips were of ventricular fibrillation (VF), ventricular tachycardia (VT), and complete heart block. Of the three 12-lead ECG tracings, one was an inferior myocardial infarction (MI), one was atrial fibrillation (AF), and one showed no abnormality. Forty-six medical students attended. Of these, 50% had received no formal training in ECG interpretation, although 89% had tried to learn ECG interpretation from books. Only 9% felt confident in their interpretation of ECG tracings. Of the rhythm-strips, 100% correctly identified VF, 96% recognised VT, and 67% identified complete heart block. Of the 12-lead ECG tracings, 61 % recognised the MI, 54% recognised AF, and only 46% successfully identified the normal ECG as such. The group were significantly worse at 12-lead ECG interpretation compared to rhythm-strips (p<0.01). The members of the group who had received formal training in ECG interpretation were significantly better at interpreting both rhythm-strips and 12-lead ECG tracings (p<0.05). It would appear that formal ECG training as an undergraduate improves PRHO interpretation of ECG tracings, and the PRHO should not interpret 12-lead ECG tracings without consulting more senior medical staff.

Cardiology↗
PubMed2000

Cerebellopontine angle lymphoma presenting as chronic mastoiditis.

Middle-ear tumours are not uncommonly mistaken for mastoiditis on presentation. We report a case of cerebellopontine angle non-Hodgkin's B-cell lymphoma originally presenting as a middle-ear inflammatory process. In mastoiditis not resolving with conventional treatment it is important to look for an underlying cause.

Aged↗
PubMed1999

Are hospitals facing a critical shortage of skilled workers?

A nationwide survey of health care human resource managers reveals that hospitals are experiencing a critical shortage of qualified job applicants in certain job categories. Computer systems personnel, registered nurses, pharmacists, and therapists are especially in short supply. Jobs that require only minimal training as well as those not directly involved in patient care are filled more easily. According to the survey respondents, shortages of qualified personnel negatively impact hospitals' operations in a variety of ways. To combat shortages of qualified job applicants, hospitals are employing a variety of tools to attract workers. Signing bonuses, above-market compensation, flexible work schedules, and myriad perks are being used to entice and retain qualified workers.

Allied Health Personnel↗
PubMed1998

The role of biomineralization in microbiologically influenced corrosion.

Synthetic iron oxides (goethite, alpha-FeO.OH; hematite, Fe2O3; and ferrihydrite, Fe(OH)3) were used as model compounds to simulate the mineralogy of surface films on carbon steel. Dissolution of these oxides exposed to pure cultures of the metal-reducing bacterium, Shewanella putrefaciens, was followed by direct atomic absorption spectroscopy measurement of ferrous iron coupled with microscopic analyses using confocal laser scanning and environmental scanning electron microscopies. During an 8-day exposure the organism colonized mineral surfaces and reduced solid ferric oxides to soluble ferrous ions. Elemental composition, as monitored by energy dispersive x-ray spectroscopy, indicated mineral replacement reactions with both ferrihydrite and goethite as iron reduction occurred. When carbon steel electrodes were exposed to S. putrefaciens, microbiologically influenced corrosion was demonstrated electrochemically and microscopically.

Biodegradation, Environmental↗
PubMed1995

Intracerebral distribution of infectious amyloid protein in spongiform encephalopathy.

We studied the regional distribution of infectious amyloid protein by western immunoblots of brain tissue extracts from 37 patients with different forms of spongiform encephalopathy, i.e., 16 sporadic cases, 18 familial cases with a variety of mutations, and 3 iatrogenic cases. In sporadic and familial Creutzfeldt-Jakob disease, amyloid protein concentrations were usually highest in the frontotemporal regions of the cerebral cortex, whereas iatrogenic Creutzfeldt-Jakob disease and Gerstmann-Sträussler-Scheinker syndrome had as high or higher concentrations in the deep cerebral nuclei and cerebellum. As a group, familial cases had lower amyloid protein concentrations than either sporadic or iatrogenic cases, and fatal familial insomnia patients had the lowest concentrations found in any form of disease. This hierarchy of amyloid protein concentrations corresponds to the experimental transmission rates observed for each form of disease and is consistent with the concept that the protein molecule is an integral component of the infectious agent. Regional amyloid protein pattern analysis of brain and spinal cord may help to distinguish sporadic from environmentally acquired infections, as for example, cases of human disease suspected to have arisen from exposure to sheep or cows infected with scrapie or bovine spongiform encephalopathy.

Aged↗
PubMed1995

Sexual harassment in the hospital industry: an empirical inquiry.

A 1994 survey of hospital HRMs has revealed that charges of sexual harassment within the health care industry are increasing at an alarming rate. Most charges are filed by women who claim they were victims of "hostile environments." Nurses levy the largest number of complaints, followed by clerical/secretarial personnel, technicians, custodial workers, food service personnel, and therapists. Most charges are filed against coworkers. Approximately 10 percent of all charges of sexual harassment in hospitals are brought against physicians.

Employee Grievances↗
PubMed1995

Neurologic manifestations of in utero cocaine exposure in near-term and term infants.

OBJECTIVE: To determine whether the incidence of neurosonographic and neurologic abnormalities is higher in cocaine-exposed infants at birth. METHODS: In utero exposure to cocaine was investigated in 39 term and near-term infants with positive urine screens for cocaine only and 39 matched control infants without drug exposure admitted to the regular term newborn nursery. Serial evaluations were performed on each infant on postnatal days 1 and 2 and included a cranial sonogram, a neurologic and behavioral assessment for drug withdrawal, and Doppler interrogation of the anterior and middle cerebral arteries. RESULTS: There were no differences between groups in neurosonographic abnormalities. Grade I or II intraventricular hemorrhage occurred in 11% of cocaine-exposed and 11% of control infants. There were no cases of grade III intraventricular hemorrhage, cystic periventricular leukomalacia, or neonatal stroke. Head size was smaller in cocaine-exposed infants, ie, 32.7 +/- 0.1 cm versus 33.8 +/- 0.1 cm. The neurologic examination was similar between groups with regard to tone, reflexes, and cranial nerves. Behavioral scores were higher on both days, in cocaine-exposed versus control infants, ie, 4.4 +/- 0.5 versus 2.7 +/- 0.03 on day 1 and 5.0 +/- 0.5 versus 1.71 +/- 0.31 on day 2. Cerebral blood flow velocity measurements in the anterior cerebral artery were similar between groups on both days of examination. However, cocaine-exposed infants demonstrated a significant increase in flow velocity from day 1 to day 2, ie, 0.48 +/- 0.03 to 0.57 +/- 0.04. There was a concomitant decrease in the pulsatility index from day 1 to day 2 in the cocaine-exposed, ie, 0.74 +/- 0.02 to 0.69 +/- 0.02, but not in the control infants. No differences were noted in the flow velocities in the middle cerebral arteries between groups. CONCLUSIONS: Term and near-term infants admitted to a regular nursery who are exposed to cocaine in utero: (1) do not exhibit an increased incidence of neurosonographic abnormalities; (2) do exhibit altered behavior consistent with drug withdrawal; and (3) do demonstrate changes in flow velocity in the anterior cerebral artery consistent with the vasoconstrictive effects of the drug. However, these changes were not accompanied by changes in the neurologic examination or altered care. The long-term neurodevelopmental implications of these subtle abnormalities in the neonatal period remain to be determined.

Blood Flow Velocity↗
PubMed1994

Alkylation of proteins by artemisinin. Effects of heme, pH, and drug structure.

Artemisinin and its derivatives are a promising new class of antimalarial agents containing an endoperoxide bridge. [14C]Artemisinin alkylated various proteins in vitro. Between 5 and 18% of added drug bound to hemoproteins such as catalase, cytochrome c, and hemoglobin. However, it did not react with heme-free globin. For catalase and hemoglobin, most of the drug reacted with the protein moiety rather than the heme. Artemisinin bound to human serum albumin (HSA) more efficiently at pH 8.6 than 7.4, more efficiently in Dulbecco's PBS than in Tris-HCl buffer, and better when HSA had been made fatty acid-free. Dihydroartemisinin also bound to HSA, whereas deoxyartemisinin, an inactive derivative, did not. There was no binding between DNA and artemisinin. These data provide insight into the mechanism of the reaction between artemisinin and proteins.

Alkylating Agents↗
PubMed1994

Perinatal research and its support. Corporate contributions at McGill University.

Three technologic projects with potentially patentable end results are slowly evolving in the Department of Obstetrics and Gynecology, McGill University and Royal Victoria Hospital. A tax shelter infusion of a significant amount of venture capital developed opportunities for all three projects over two years. The three projects--fetal heart rate tracing analysis related to fetal outcome, a distributed and intelligent data acquisition system and selected ultrasonic three dimensional imaging--were advanced considerably, and their results are expressed in outline. The effects of such infusions of business support into an environment of sparse research grant support have been extremely encouraging to the investigators, but the department, with its obligations of ongoing research, teaching and patient care, must develop the next steps with care, although one of the projects has been extended by an interested corporation.

Capital Financing↗
PubMed1994

Primary angiitis of the central nervous system: unusual MR appearance.

The MR findings of a biopsy-proved case of primary angiitis of the central nervous system are described and compared with previously reported cases. Multiple punctate and linear areas of gadopentetate dimeglumine enhancement were present in the brain stem and white matter and appear to correspond to the inflammatory reaction of the small perforating vessels and perivascular tissues seen in the pathologic specimen.

Arteries↗
PubMed1991

Reduced serum inhibin concentrations during ovulatory cycles of estrogen-treated rhesus monkeys: an indicator of FSH bioactivity.

Female rhesus monkeys treated with exogenous estrone initially were anovulatory. Although estrone and estradiol concentrations were maintained 1.5- to 2.5-fold elevated, i.e. in the midfollicular range, ovulatory cycles resumed in three of four animals after 6-15 months of anovulation. During the ovulatory cycles the serum bio LH concentrations were the same in estrone-treated animals as during ovulatory cycles of control monkeys, but the daily basal serum FSH concentrations detectable by RIA were significantly reduced during the ovulatory cycles of the estrone-treated animals compared to the cycles of the controls. In the present study serum inhibin concentrations were measured to determine whether or not they were increased and the cause of the selective decrease in FSH concentrations in the estrogen-treated monkeys. Serum LH, FSH, progesterone, and inhibin concentrations were measured by RIA in blood samples collected during the third year of continuous estrogen treatment. The lack of an effect of elevated estrogen on LH concentrations and a significant estrogen-induced decrease in serum FSH concentrations during ovulatory cycles was confirmed (FSH, control: 5.6 +/- 0.68 ng/ml; estrogen-treated: 2.5 +/- 0.09 ng/ml; P = 0.01). There was also a significant decrease in the serum inhibin concentrations detectable by RIA during the follicular phase of the estrone-treated monkeys compared to the follicular phase of the control animals (119 +/- 17 vs. 462 +/- 105 microliter eq/ml; P = 0.04). These results indicate that the lower serum concentrations of FSH in the estrogen-treated monkeys were not a result of an increase in ovarian secretion of inhibin. The lower inhibin concentrations suggest that FSH bioactivity, as well as immunoreactive FSH, is significantly reduced during the ovulatory cycles of the estrone-treated monkeys. Even though the estrogen treatment decreased the FSH bioactivity, sufficient FSH secretion occurs in the presence of the elevated estrone and estradiol concentrations to induce and support apparently normal ovulatory cycles.

Animals↗