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Biomedical subjects

A Russell

Publications and source records attributed to A Russell.

At least 91 records · Page 5Linked to original sources
PubMed1995

No linkage to the 3 beta-HSD gene cluster in a kindred affected with 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase deficiency and early onset hepatic failure.

We studied the segregation of the genes for 3 beta-hydroxy-C19/21-steroid dehydrogenase types I and II (3 beta-HSD I and II) in a consanguineous family affected with 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase (3 beta-OH-C27-SD) deficiency. The results show that the C27 and C19/21 steroid dehydrogenase activities are encoded by distinct genes that are not in genetic linkage. Further kindreds would assist in screening for linkage of 3 beta-OH-C27-SD to other members of the 3 beta-hydroxysteroid dehydrogenase gene family.

3-Hydroxysteroid Dehydrogenases↗
PubMed1995

The expression of the gene coding for parathyroid hormone-related protein (PTHrP) during tooth development in the rat.

By means of in situ hybridisation studies, it is shown that parathyroid hormone-related protein (PTHrP) mRNA is strongly expressed in the developing enamel organs of rat teeth. In particular, the cervical loop hybridises strongly with the PTHrP probe and expression is maintained at this site throughout life in the permanently erupting incisor teeth. In mature molar teeth, expression is downregulated to low levels and confined to the epithelial cell rests of Malassez and/or cementoblasts which may derive from these. The gene is also expressed at low levels in the tissue overlying the erupting molars and, thereafter, in the junctional epithelia and connective tissue cells of the epithelial attachment on all tooth surfaces. The premise that PTHrP may undergo post-translational processing and that the resultant products could act in different ways raises the possibility of its exerting multiple paracrine actions during tooth development. These could include the control of cell division and local vascular dilation during development.

Animals↗
PubMed1995

Speaking fundamental frequency changes over time in women: a longitudinal study.

Archival recordings of the human voice are a relatively untapped resource for both longitudinal and cross-sectional research into the aging voice. Through the availability of collections of old sound recordings, speech pathologists and voice scientists have access to a wealth of data for research purposes. This article reports on the use of such archival data to examine the changes in speaking fundamental frequency (SFF) in a group of Australian women's voices over the past 50 years, and discusses the benefits and problems associated with using archival data. Recordings made in 1945 of women were compared with recordings of the same women made in 1993 to investigate the changes in SFF with age. The results demonstrate a significant lowering of SFF with age in this group of Australian women. The implications for the interpretation of cross-sectional data on the aging voice, the use of archival data in voice research, and the need for further research using archival data are discussed.

Adolescent↗
PubMed1995

Localization of growth hormone receptor/binding protein messenger ribonucleic acid (mRNA) during rat fetal development: relationship to insulin-like growth factor-I mRNA.

Although GH plays a key role in postnatal growth, prenatal growth is thought to be GH independent. However, recent data has shown GH receptor/binding protein (GHR/BP) to be present in rat fetal tissues as early as fetal stage E12. The aim of the present study was to investigate tissue-specific production of the GHR/BP messenger RNA (mRNA) and its relationship to locally transcribed insulin-like growth factor-I (IGF-I) mRNA in the fetus. We have used in situ hybridization to localize GHR/BP and IGF-I mRNAs in 16.5-, 18.5-, and 20.5-day-old rat fetuses. Furthermore, because the two parameters of the IGF-I gene differentially respond to GH stimulation, we have also investigated the presence and localization of promoter-specific IGF-I mRNAs. We found the distribution of IGF-I and GHR/BP mRNAs to be widespread but distinct during the fetal stages examined. High levels of IGF-I mRNA were found in connective tissues or their precursors, including the dermis, perichondrium, and gut. In contrast, GHR/BP mRNA exhibited three distinct patterns of distribution. First, GHR/BP mRNA was found at epithelial sites adjacent to sites of IGF-I transcription. Second, GHR/BP and IGF-I mRNAs were found to colocalize in some connective tissues, but GHR/BP mRNA levels in these sites were often lower than at other sites (i.e. epithelial) of GHR/BP gene transcription. Third, GHR/BP mRNA was also found in regions remote from IGF-I mRNA, including the nerve ganglia and inner olfactory bulb. Using promoter-specific IGF-I RNA probes, we detected only promoter 1 transcripts in all fetal tissues examined. The only exception occurred in specialized epithelial cells of the cochlea where we detected high levels of both promoter 1- and 2-derived IGF-I transcripts. We have thus demonstrated a distinct distribution of GHR/BP and IGF-I mRNAs in the developing rat fetus with coordinate expression at some sites. These findings suggest a role of GH or a GH-like peptide, acting both directly and indirectly via IGF-I, in fetal growth and development.

Animals↗
PubMed1994

The influence of life events on the subsequent course of psychotic illness. A prospective follow-up of the Camberwell Collaborative Psychosis Study.

Fifty-nine psychotic patients with acute onset of illness, who had been interviewed about their experience of stressful life events before the episode, were followed up for an average of 42 months. Thirty patients (51%) had experienced a stressful life event in the 3 months immediately before onset (EV+), 29 had not (EV-). In patients with an RDC diagnosis of affective disorder or unspecified functional psychosis, the presence of stressful life events was associated subsequently with milder symptom severity, less time spent in hospital, more treatment for depressive symptoms and less for psychotic symptoms. In schizophrenia, differences were less apparent, but patients with event associated episodes had less need of anti-psychotic maintenance medication over the follow-up period and tended to have spent more time in complete remission. EV+ schizophrenic subjects also had higher morbid risk for schizophrenia in their first degree relatives, and tended to be female and to have less typical symptoms than EV- schizophrenic patients.

Adult↗
PubMed1994

A high-performance liquid chromatographic method for the simultaneous determination of venlafaxine and O-desmethylvenlafaxine in biological fluids.

A rapid, accurate, and sensitive high-performance liquid chromatographic (HPLC) method for simultaneous determination of venlafaxine (V) and O-desmethylvenlafaxine (ODV) in plasma and urine has been developed. V and ODV are extracted from plasma using a liquid-liquid extraction procedure, chromatographed on a Supelcosil LC-8DB column, and quantitated by UV detection at 229 nm. Linearity was established over the range 10-500 ng/ml for V and 7.2-720 ng/ml for ODV using 1.0 ml of human, rat, dog, and mouse plasma. For urine, for both analytes, an analytical range 0.1-10.0 micrograms/ml was established. Accuracy of > +/- 10% about the theoretical mean was achieved for all matrices, with intra- and interday coefficients of variation for precision of < 10%. Endogenous components in plasma and/or urine or known metabolites of V do not interfere in the determination of the analytes. For both V and ODV a quantitation limit of 10 ng/ml for plasma was adequate for their estimation over a period of three half-lives, following administration of a pharmacologic dose in man, and the limit of 0.1 microgram/ml, for urine, can monitor excretion of as little as 0.5% of the dose.

Animals↗
PubMed1994

Age at onset, sex, and familial psychiatric morbidity in schizophrenia. Camberwell Collaborative Psychosis Study.

BACKGROUND: Although a genetic component in schizophrenia is well established, it is likely that the contribution of genetic factors is not constant for all cases. Several recent studies have found that the relatives of female or early onset schizophrenic patients have an increased risk of schizophrenia, compared to relatives of male or late onset cases. These hypotheses are tested in the current study. METHOD: A family study design was employed; the probands were 195 patients with functional psychosis admitted to three south London hospitals, diagnosed using Research Diagnostic Criteria (RDC), and assessed using the Present State Examination (PSE). Information on their relatives was obtained by personal interview of the mother of the proband, and from medical records. Psychiatric diagnoses were made using Family History-Research Diagnostic Criteria (FH-RDC), blind to proband information. RESULTS: There was a tendency for homotypia in the form of psychosis within families. The lifetime risk of schizophrenia in the first degree relatives of schizophrenic probands, and the risk of bipolar disorder in the first degree relatives of bipolar probands, were 5-10 times higher than reported population risks. Relatives of female and early onset (< 22 years) schizophrenic probands had higher risk of schizophrenia than relatives of male and late onset schizophrenic probands. However, this effect was compensated in part by an excess of non-schizophrenic psychoses in the relatives of male probands. CONCLUSIONS: These results suggest a high familial, possibly genetic, loading in female and early onset schizophrenia, but do not resolve the question of heterogeneity within schizophrenia.

Adult↗
PubMed1994

Evaluation and treatment of patients receiving radiation for cancer of the rectum or sigmoid colon in the United States: results of the 1988-1989 Patterns of Care Study process survey.

PURPOSE: For the first time, a Patterns of Care Study (PCS) was conducted in 1989 to determine the national practice standards of radiation oncologists in evaluating and treating adenocarcinoma of the rectum and sigmoid colon. MATERIALS AND METHODS: A national survey of 73 institutions using two-stage cluster sampling was conducted, and specific information on 408 patients from 69 facilities with adenocarcinoma of the rectum and sigmoid colon who received radiation as part of definitive or adjuvant management was collected. RESULTS: Using the modified Astler-Coller (MAC) pathologic staging system, the stage distribution was as follows: A, 0.5%; B1, 4.4%; B2, 23.5%; B3, 5.1%; C1, 8.9%; C2, 30.2%; and C3, 6.6%. Preoperative radiation was used in 29% of patients, but the total dose was greater than 40 Gy in only 20%. Seventy-three percent of patients received postoperative radiation, with approximately 4% receiving combined preoperative and postoperative radiation. Chemotherapy was administered to 44% of patients overall, representing 55% of patients with disease through the bowel wall and/or involving lymph nodes. Only 37% of all patients received chemotherapy concurrent with radiation. An abdominoperineal resection was used in 43%; a low anterior resection was used in 43% as well, while 5% underwent other types of bowel resection. Approximately 8% of patients were treated with a local curative procedure less than bowel resection (eg, local excision, endoscopic resection, fulguration, or contact radiation). At least one third of patients had interruption in their pelvic irradiation of greater than 3 days. There was no statistically significant difference in the frequency of treatment interruptions by dose per fraction or whether chemotherapy was given concurrent with radiation. There was no significant difference in total dose delivered to patients staged B2 and higher treated without chemotherapy compared with concurrent chemotherapy and radiation. Also, there was no significant difference in total dose delivered to patients with B1 and B2, or C1 and C2 versus B3 or C3 cancer. CONCLUSION: This study was conducted on patients treated just before the 1990 National Institutes of Health consensus guidelines issued on the management of colon and rectal cancer. This study indicates that the minority of patients treated with radiation in 1988 and 1989 received concurrent chemoradiation, as currently recommended. Additionally, insofar as present studies are investigating important issues such as the use of sphincter-sparing procedures, preoperative radiation and chemotherapy, and the importance of radiation dose and scheduling with chemotherapy, the information provided by this study will serve as a useful baseline to track future changes in rectal cancer evaluation and management.

Adenocarcinoma↗
PubMed1994

Outcome in patients with rheumatoid arthritis receiving prednisone compared to matched controls.

OBJECTIVE: To determine the longterm outcome including disease activity, mortality, and adverse events in patients with rheumatoid arthritis (RA) treated with prednisone. METHODS: A case-control study was performed, based on our cohort of 893 mostly Caucasian patients with adult onset RA, followed since 1966. Data collection was based on protocols and included single physician global assessment. Prednisone was started in 122 patients (85 women, 37 men) after 1966. All were matched for age, sex, disease duration, and global assessment to 122 controls from the same cohort who have never received prednisone. RESULTS: Mean disease duration before prednisone was 14.1 years. Mean duration of use was 6.9 years with a mean dose of 8.0 mg/day. Prednisone was eventually stopped in 34% of patients. Life expectancy and causes of death were similar in both groups. No differences in hemoglobin, erythrocyte sedimentation rate, global assessment, Lansbury index, functional class or Health Assessment Questionnaire (HAQ) disability index were seen between the 2 groups before or 5 years after starting prednisone. Ten years after starting prednisone, HAQ scores were similar but Lansbury and global assessment were worse in the prednisone treated group. As expected, adverse events, notably cataracts and fractures, were observed more often in the prednisone group. CONCLUSION: Case-control matching can only reduce, not eliminate, potential selection bias. Nonetheless, the lack of demonstrable longterm benefit with prednisone use in this and other studies is disconcerting. Caution and further studies are required before the more aggressive use of longterm prednisone therapy in RA is embraced.

Adolescent↗
PubMed1993

Comparative pharmacokinetics and pharmacodynamics of two marketed bid formulations of diltiazem in healthy volunteers.

Cardizem SR and Bi-Tildiem were both approved in their respective countries on the basis of clinical trials demonstrating efficacy and safety in the treatment of angina pectoris. In this cross-over randomized study, we assessed whether these two sustained-release formulations of diltiazem have equivalent pharmacokinetic and pharmacodynamic profiles. Twenty-four young healthy male volunteers were hooked to Holters and ambulatory blood pressure monitors for 24 h to establish baseline systolic blood pressure (SBP), diastolic blood pressure (DBP), sinus rate and PR intervals. They then received a single dose of 120 mg of diltiazem from one formulation. The pharmacodynamic measurements were recorded for a further 24 h and blood samples were collected over 36 h for evaluation of diltiazem in plasma by a high-performance liquid chromatogrpahic (HPLC) method. The procedures were repeated with the alternate formulation after a 7 d wash-out. Pharmacokinetics showed statistically significant (p < 0.01) differences in AUC0-12 with means (+/- SD) of 519.2(+/- 172.8) and 429.6(+/- 147.2) ng h ml-1, AUC0-36 of 835.6(+/- 281.6) and 730.9 (+/- 271.5) ng h ml-1 and Cmax of 89.1(+/- 30.3) and 61.1(+/- 21.2) ng ml-1 for Cardizem SR and Bi-Tildiem, respectively. The only pharmacodynamic parameter showing a statistically significant difference in change from baseline between the two formulations was DBP with mean (+/- SD) change in AUC0-12 of -13.6(+/- 20.8) and +8.4(+/- 31.7) mm Hg h (p = 0.0135) and in AUC0-24 of -33.0(+/- 43.7) and -0.3(+/- 59.2) mm Hg h (p = 0.0463) for Cardizem SR and Bi-Tildiem, respectively. These findings suggest that assessment of efficacy of sustained-release formulations of diltiazem by bioequivalence could be misleading. They also confirm that a single dose of diltiazem does not elicit a significant pharmacodynamic response in healthy volunteers. Equivalence for such formulations should therefore be demonstrated by pharmacodynamic evaluation or clinical studies in a patient population.

Adult↗
PubMed1993

Movement disorders with cerebral toxoplasmosis and AIDS.

Movement disorders occur in some patients with cerebral toxoplasmosis with HIV-1 infection. Such movement disorders have not been described in patients with cerebral toxoplasmosis without HIV-1 infection. This report discusses their diagnostic features, aspects of management, and possible mechanisms underlying the pathogenesis of the movement disorders.

AIDS-Related Opportunistic Infections↗
PubMed1993

Characteristics of normal larynges under flexible fiberscopic and stroboscopic examination: an Australian perspective.

The purpose of this study was to investigate the structure and function of larynges of 35 subjects with normal voices. Volunteers aged between 20 and 50 years with no history of voice disorders or laryngeal surgery, no current allergies, no formal voice training, and no hyperactive gag reflex were required to perform various vocal manoeuvres that were carried out under continuous and stroboscopic light. An assessment form was devised to record the condition and function of the larynx. The videotapes of the procedure were rated by experienced judges. The Australian Fiberscopic Profile was devised to record the relevant parameters under continuous light. Videostroboscopic ratings were carried out using the Bless protocol rating. High interjudge agreement was found across the two rating profiles.

Adolescent↗
PubMed1993

Short fat questionnaire: a self-administered measure of fat-intake behaviour.

A brief questionnaire has been developed to measure behaviour related to dietary fat intake. It is self-administered and self-coded. Mean completion time is about three minutes. Criterion validity was assessed by comparison with a well-established food frequency questionnaire using 124 adults from Newcastle and Sydney. The correlations with the questionnaire scores were: r = 0.55 for total fat as a percentage of total energy, r = 0.67 for saturated fat as a percentage of total energy, and r = 0.44 for polyunsaturated to saturated fat ratio. Reproducibility was assessed by re-use by 25 subjects after seven to nine months (r = 0.85). When used in a community survey of other 300 randomly chosen people in the Hunter Region, the mean scores for men and for women and among different age groups were significantly different. The questionnaire was strongly associated with other scales measuring attitudes, behaviour and knowledge related to low-fat diets. The questionnaire appears suitable for rapid self-assessment by subjects, and as it directs their attention to aspects of their diet which might need improvement, it could be used for health education. It might also be used for epidemiological studies to rank subjects broadly according to their fat-intake behaviour.

Adolescent↗
PubMed1993

Premorbid social underachievement in schizophrenia. Results from the Camberwell Collaborative Psychosis Study.

In an investigation of the timing and precursors of social decline in schizophrenia and affective psychosis, 195 subjects from the Camberwell Collaborative Psychosis Study were currently of lower social class than were their fathers. A comparison between father's occupation and proband's best premorbid occupational level indicated underachievement confined to DSM-III schizophrenia, there being no such effect in affective psychosis. Decline in social status following onset of psychosis, analysed by comparing best premorbid occupation with current occupation, was marked in both schizophrenia and affective psychosis, indicating a non-specific effect. Schizophrenic patients who failed to achieve their fathers' social status had poorer educational qualifications than those who equalled or bettered their paternal social class, despite similar premorbid IQ (NART) scores and age at onset of psychosis. These results indicate that schizophrenia may be manifest before the onset of psychosis, and lend weight to the notion of a developmental origin to this disorder.

Adolescent↗