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Biomedical subjects

S Montgomery

Publications and source records attributed to S Montgomery.

At least 37 records · Page 2Linked to original sources
PubMed1999

Treatment resistant depression: methodological overview and operational criteria.

A wide variety of definitions are used for Treatment Resistant Depression (TRD), considering various criteria and different concepts. Some of the key issues are: the diagnosis, the treatment adequacy in terms of dose and duration, the treatment response assessment and the number of failed therapeutic trials required. Systematic research has been characterizing the concept and criteria to define the different variables involved. Lack of consensus on these issues limits comparison across clinical trials and interpretation of treatment efficacy in the management of treatment resistant patients. Through reanalyzes of available data, we point out the limits of TRD definitions and propose conceptual and operational criteria for a collaborative research project on TRD. It appears that a number of variables commonly associated to treatment resistance are independent of patients characteristics and mainly refer to misdiagnosis and inadequate treatment. The proposed criteria are intended for therapeutic trials in TRD, combining the evaluation of treatment efficiency and the validation of the concept of TRD itself. Major depression with poor response to two adequate trials of different classes of antidepressants is proposed for an operational definition of TRD. Rationale for this definition is discussed in contrast to alternative definitions.

Antidepressive Agents↗
PubMed1999

Pronuclear orientation, polar body placement, and embryo quality after intracytoplasmic sperm injection and in-vitro fertilization: further evidence for polarity in human oocytes?

Three hypotheses were tested: (i) the distance between first and second polar bodies (PB) may relate to embryo morphology, (ii) that the orientation of pronuclei (PN) relative to PB may relate to embryo morphology, (iii) that the placement of a spermatozoon in a fixed plane relative to the first PB [intracytoplasmic sperm injection (ICSI)] may alter PN/PB orientation relative to in-vitro fertilization (IVF). A total of 251 two pronuclear (2PN) embryos (124 ICSI, 127 IVF) from 64 patients was studied. Angles were measured between the PN axis and the nearest PB (alpha), the furthest PB (beta), and between the two PB (gamma). On day 2, the morphological grades of embryos were recorded. gamma ranged from 0 to 150 degrees and was not significantly different for ICSI or IVF embryos of different grades; however, an unusual distribution of gamma suggested different populations of oocytes. The first hypothesis was rejected. alpha and beta ranged from 0 to 90 degrees : alpha did not relate significantly to embryo grade, but beta increased significantly with decreasing quality of ICSI embryos (P < 0.05) and the total group (P < 0.01), supporting hypothesis (ii). The difference in beta between ICSI and IVF embryos was not significant, so hypothesis (iii) was unproven. Significant differences between ICSI and IVF embryos in PN positions, irregular cleavage, and cleavage failure were noted.

Cell Nucleus↗
PubMed1999

Evaluation of developmentally appropriate programs for adolescent tobacco cessation.

Despite introduction of numerous smoking prevention programs in schools, tobacco use has not declined among adolescents. Schools face the dilemma of what to do with students who smoke and are not ready to quit. This study evaluated two programs based on the stages of change model. The educational program, the Tobacco Education Group (TEG), was designed for adolescents not yet thinking about quitting. The cessation program, the Tobacco Awareness Program (TAP), was intended for adolescents who want to quit. Evaluation was completed on 351 students at six public high schools. Compared to a control group of adolescent smokers not assigned to programs, both intervention groups significantly decreased tobacco use. Self-reported use was validated biochemically. Self-efficacy for quitting increased in both programs. Posttest use was predicted by posttest self-efficacy, peer support, and parental support, after controlling for initial use and initial self-efficacy.

Adolescent↗
PubMed1999

Barriers to early detection of breast cancer among women in a Caribbean population.

The purpose of this descriptive study was to identify and describe barriers to early detection of breast cancer, as well as current breast cancer screening behaviors and attitudes regarding the disease, among women aged 20 and older on the Caribbean island of Tobago. Tobago is the smaller of the two islands that make up the nation of Trinidad and Tobago. Between February and June 1996, 265 women fitting the age criteria completed a structured survey questionnaire. Women of African descent made up 89% of the respondents. In terms of age, 48% of those surveyed were between 20 and 39, 40% were between 40 and 59, and 12% were 60 or older. Barriers to early detection identified were a low level of breast self-examination, infrequent clinical breast examinations as part of regular care, unavailability of mammography services on Tobago, cost of screening, and difficulty of traveling to Trinidad for mammography. Furthermore, only a minority of the study participants had ever attended early detection or public awareness programs. The results were nearly the same for individuals with a family history of breast cancer, who would have a higher risk of occurrence of the disease. In addition, the majority of the respondents reported what can be considered a cultural barrier to early detection practices, a belief that no matter what they did, if they were to get breast cancer, they would get it. The authors recommend that mammography services be made available on Tobago. The authors also intend to use the findings to help develop an appropriate, culturally sensitive breast cancer awareness and early detection program for women on the island.

Adult↗
PubMed1999

Management of lumbar injuries in athletes.

Lumbar spine pain is a common and disabling condition affecting an athlete's ability to train and compete. The athletic management team must take a cooperative approach to diagnosis and treatment. The presentation pattern and injury history may provide an early cue to diagnosis; information gained by the trainer or therapist at the time of injury is particularly important. The unique anatomy and biomechanics of the lumbar segments leads to certain injury patterns. Knowledge of the potential motion, muscle effectors of motion and mechanisms of injury allows for a highly specific diagnosis. A meticulous physical examination with particular attention to neurological findings should be used to confirm suspicions from the athlete's symptom pattern. Early conservative treatment should be initiated for all patients except those who are mechanically unstable or neurologically impaired. Aerobic and nonpainful sports-specific training may be continued under the care of the trainer or physical therapist. This will limit the loss of skill and endurance when normal activity is resumed. Diagnosis-specific medical and physical therapy should supplement this training activity. A care team that carefully analyses the pain presentation, injury history and symptoms, and directs a diagnosis-specific treatment programme, should manage lumbar spine conditions in the athlete.

Athletic Injuries↗
PubMed1999

Exploring family relationships in cancer risk counseling using the genogram.

OBJECTIVES: The genogram is a tool that has facilitated counseling in family therapy and social work for many years. It is hypothesized that genograms may also be useful in genetic counseling, because they help the counselor to acquire more objective and consistent information from the client, as well as to incorporate family dynamics and psychosocial issues into the counseling approach. MATERIALS AND METHODS: A pilot study of genograms used as an adjunct to genetic counseling was performed at Fox Chase Cancer Center's Family Risk Assessment Program. A questionnaire was developed to elicit genograms from 38 women at risk for familial breast and/or ovarian cancer. After standard pedigree expansion, a series of questions was asked about the consultand's relationship with other family members, communication patterns within the family, attitudes toward genetic testing, family reactions to cancer, roles individuals play in the family, and significant historical or anniversary events. Relationships were defined by the consultand as close, very close, conflictual, fused and conflictual, distant, or estranged. RESULTS: The majority of relationship types reported by 38 individuals was "very close" or "close." Eighty-one % reported having close/very close relationships with their spouses, 83% reported close/very close relationships with their mothers, and 70% reported close/very close relationships with their fathers. The degree of familial cohesion as depicted by the genogram correlates positively with scores obtained on the standardized Social Adjustment Scale Self-Report (P = 0.01). CONCLUSIONS: Given the family-wide implications of genetic testing, the genogram may offer important guidance in family-targeted interventions.

Adult↗
PubMed1998

Effects of a community-based prevention program on decreasing drug use in high-risk adolescents.

OBJECTIVES: This study investigated the secondary prevention effects of a substance abuse primary prevention program. METHODS: Logistic regression analyses were conducted on 4 waves of follow-up data from sixth- and seventh-grade baseline users of cigarettes, alcohol, and marijuana taking part in a school-based program in Indianapolis. RESULTS: The program demonstrated significant reductions in cigarette use at the initial follow-up (6 months) and alcohol use at the first 2 follow-ups (up to 1.5 years). Models considering repeated measures also showed effects on all 3 substances. CONCLUSIONS: Primary prevention programs are able to reach and influence high-risk adolescents in a nonstigmatizing manner.

Adolescent↗
PubMed1997

Health and the life course: why safety nets matter.

This article argues that a life course approach is necessary to understand social variations in health. This is needed in order to take into account the complex ways in which biological risk interacts with economic, social, and psychological factors in the development of chronic disease. Such an approach reveals biological and social "critical periods" during which social policies that will defend individuals against an accumulation of risk are particularly important. In many ways, the authors of modern welfare states were implicitly addressing these issues, and the contribution of these policies to present day high standards of health in developed countries should not be ignored.

Health Policy↗
PubMed1997

Biologically erodable microspheres as potential oral drug delivery systems.

Biologically adhesive delivery systems offer important advantages over conventional drug delivery systems. Here we show that engineered polymer microspheres made of biologically erodable polymers, which display strong adhesive interactions with gastrointestinal mucus and cellular linings, can traverse both the mucosal absorptive epithelium and the follicle-associated epithelium covering the lymphoid tissue of Peyer's patches. The polymers maintain contact with intestinal epithelium for extended periods of time and actually penetrate it, through and between cells. Thus, once loaded with compounds of pharmacological interest, the microspheres could be developed as delivery systems to transfer biologically active molecules to the circulation. We show that these microspheres increase the absorption of three model substances of widely different molecular size: dicumarol, insulin and plasmid DNA.

Adhesiveness↗
PubMed1994

The lymphoblast beta-adrenergic receptor in bipolar depressed patients: effect of chronic incubation with lithium chloride.

We have recently reported a study of beta-adrenergic receptor binding characteristics in lymphoblast cell lines derived from patients with bipolar disorder (BD) and healthy, matched control subjects. In the present study we have investigated the effects of incubating cells from the same subjects with lithium chloride (1 mM) for 7 days prior to assay. There was no difference in beta-adrenergic receptor number between control and BD cell lines and incubation with lithium had no effect on receptor number in either group. Exposure of the cells to isoprenaline (1 nM) for 24 h immediately prior to assay caused significantly less down-regulation in BD cells (15 +/- 5%) than control cells (39 +/- 4%), as described previously. Incubation with lithium significantly increased the down-regulation response to isoprenaline in BD cells (39 +/- 6%) but not in control cells (30 +/- 7%). After lithium, the agonist-induced decrease in beta-AR number in BD cells was no longer significantly different from that in control cells. We conclude that lithium selectively enhanced the agonist down-regulation of beta-adrenergic receptors in cells derived from patients with bipolar disorder. The functional significance of this result and the potential biochemical mechanisms responsible for this effect are discussed.

Adult↗
PubMed1993

The lymphoblast beta-adrenergic receptor in bipolar depressed patients: characterization and down-regulation.

beta-Adrenergic receptor binding and adenylyl cyclase activity were examined in lymphoblast cell lines established from 12 patients with bipolar disorder and 10 unrelated healthy control subjects. No significant differences were found in [125I]iodocyanopindolol binding affinity or capacity or in isoprenaline-stimulated cAMP response. Incubation of lymphoblasts with isoprenaline (1 nM) for 24 h prior to assay reduced both receptor number and adenylyl cyclase activity. The extent of receptor down-regulation was significantly less in cells of bipolar disorder patients (20 +/- 5%) compared to controls (40 +/- 4%). Desensitization of adenylyl cyclase, however, was reduced to a similar degree in bipolar (65 +/- 14%) and control (68 +/- 20%) subjects. We conclude that basal beta-adrenergic receptor characteristics are not altered in bipolar disorder but that agonist down-regulation of receptor number may be less efficient than in control cells. The functional implications of this effect are discussed.

Adenylyl Cyclases↗
PubMed1993

Substance use among youth seen at a community-based health clinic.

Despite recent surveys reporting a decline in adolescents' use of alcohol and other drugs in the general population, substance abuse may actually be increasing among particular subgroups of high-risk youth. This study examined the prevalence of alcohol and other drug use reported by 1121 youth, ages 12-24 years, seen for an initial medical visit at a free community-based primary health clinic. The clinic, located in the Hollywood/Wilshire area of Los Angeles, serves both homeless (62%) and non-homeless (38%) youth. Bivariate and multivariate analyses revealed that the homeless youth were significantly more likely to report use of alcohol and illicit drugs (marijuana, stimulants, hallucinogens, and narcotics) and prior involvement in injecting drug use (IDU). Variables found to be significantly associated with substance use among the homeless youth included length of time homeless, an attempted suicide, physical and sexual abuse, and involvement in survival sex/prostitution. Among the non-homeless youth, age of first intercourse, a previous suicide attempt, and a history of physical and sexual abuse were significantly associated with substance use. These findings suggest that rates of alcohol and other drug use may be higher among youth seen at community-based primary health clinics, particularly homeless youth underscoring the need for screening for these risk variables.

Adolescent↗
PubMed1993

Effect of restoration thickness on the sealing ability of TERM.

An in vitro study was done using a fluid filtration device to compare microleakage of Temporary Endodontic Restorative Material (TERM) at various thicknesses. Forty-four extracted mandibular molars had their roots removed at the cementoenamel junction, occlusal table flattened, and a standardized endodontic access made in the crown. The teeth were restored with TERM in thicknesses of 1, 2, 3, and 4 mm, and quantitatively measured for leakage (microliters/min) at intervals of 1 and 24 h and 1, 3, and 5 wk. Thermocycling was accomplished at the 5-wk interval. Positive controls received 4-mm-thick IRM or gutta-percha restorations and were measured at 24 h only. Repeated measures of analysis of variance found no significant difference (p < 0.05) in leakage values in any group over time or between any of the different thicknesses. Positive controls showed significantly more leakage than all other groups. TERM maintained as tight a seal at 1-, 2-, and 3-mm thicknesses as it did at 4 mm and may be suited for clinical situations where less than 4 mm of restorative space exists.

Analysis of Variance↗
PubMed1992

Another look at root canal instrumentation.

Several aspects of root canal instrumentation need additional research. Various factors must be considered in an analysis of instrumentation of the root canal system: the dentin that is cut; the technique used to cut it; the design of the instruments; the material and manufacturing process used to make the instruments; the irrigant used during the procedure; and the anatomic configuration of the root canal system. An analysis of these factors clearly indicates that existing root canal instruments and techniques are less than ideal and, in fact, do not accomplish what is expected of them. Root canals must be properly, but, at the same time, destructive and unnecessary removal of dentin should be kept to a minimum. The Flex-R and Canal Master instruments were developed to address some of the shortcomings of existing instruments and techniques. More scientifically based research is needed to fully evaluate these new instruments and techniques and to develop future instruments.

Dental Cavity Preparation↗
PubMed1992

Evaluation of Thermafil obturation of curved canals prepared by the Canal Master-U system.

A dye penetration study was performed to compare the apical seals obtained with laterally condensed gutta-percha and Thermafil. The sample group contained 40 teeth with curved canals which had been prepared with the Canal Master-U System. Canal curvature was measured and the teeth were decalcified, cleared, and linear dye penetration was measured. Thermafil had statistically more linear leakage as verified by a Wilcoxon test (p < 0.001). Thermafil also had greater variability in the apical seal than did laterally condensed gutta-percha as verified by an F test (p < 0.001). A Spearman correlation analysis (p > 0.05) showed that there was no correlation between root curvature and linear dye penetration.

Analysis of Variance↗
PubMed1992

Cervical canal leakage after internal bleaching.

The effects that walking bleach procedures had on root canal filling leakage and the extent of dentinal penetration were studied. Forty teeth were divided into four groups: 1--GP, set sealer, no base; 2--GP, set sealer, 2-mm Cavit base; 3--GP, unset sealer, no base; and 4--GP, unset sealer, 2-mm Cavit base. All were bleached for 7 days, fresh bleach was added for another 7 days, then methylene blue dye was placed for 5 days. The extent of dye penetration apically along the root canal filling and through the dentinal tubules was evaluated. The results indicate that 2 mm of Cavit was sufficient to significantly reduce linear leakage and dentinal penetration. The Cavit should be placed to a level slightly coronal to the facial cementoenamel junction. Teeth with cemental defects demonstrated greater perpendicular dye penetration in the areas of the defects than those with intact cementum. The data from this study suggest the use of a base material over gutta-percha in clinical practice prior to internal walking bleach procedures.

Analysis of Variance↗