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Biomedical subjects

D Clark

Publications and source records attributed to D Clark.

At least 379 records · Page 21Linked to original sources
PubMedDate not supplied

The effects of the combination of chlorhexidine/thymol- and fluoride-containing varnishes on the severity of root caries lesions in frail institutionalised elderly people.

OBJECTIVES: To compare the clinical effects of a fluoride-containing varnish (Fluor-Protector) in combination with a chlorhexidine-containing varnish (Cervitec) on existing root caries lesions in a group of frail elderly subjects. METHODS: A randomised double blind longitudinal study was utilised. Subjects (n = 102) were randomly allocated to a Test or Placebo group. All leathery and soft root caries lesions in all subjects were coated with Fluor-Protector while the lesions in the Test group were also coated with Cervitec and the lesions in the Placebo group were coated with a Placebo varnish. Treatments were repeated five times in a 12-month period. Clinical parameters associated with root caries, measurements of individual lesions and salivary levels of caries associated bacteria were made at intervals. RESULTS: The clinical severity of the lesions in the Test group did not change significantly during the 12-month study period. In the Placebo group the mean lesion width and lesion height and length of exposed root increased significantly and the lesions were significantly closer to the gingival margin. There were no significant changes in the salivary levels of caries-associated microorganisms after 12 months although, in both groups, there was initially a significant reduction in the salivary levels of mutans streptococci. CONCLUSIONS: The combination of Fluor-Protector and Cervitec is a useful, simple, quick and non-invasive method for the control and management of existing root caries lesions. The procedure could be performed by a dental hygienist and may be usefully applied in other high-risk groups including persons with Parkinson's disease, debilitating neuromuscular conditions and dry mouth from whatever cause.

Aged↗
PubMedDate not supplied

Fluoxetine in adolescents with major depression and an alcohol use disorder: an open-label trial.

Recently, a first placebo-controlled study of an selective serotonin reuptake inhibitor (SSRI) medication was conducted among a sample of adolescents with major depression by Emslie et al. [Arch. Gen. Psychiatry 54 (1997) 1031.]. That study demonstrated efficacy for fluoxetine vs. placebo for treating adolescents with major depression. However, to date, no studies have been conducted to assess the efficacy of fluoxetine or any other SSRI medication in adolescents with major depression in combination with an alcohol use disorder (AUD). In this study, the authors investigated whether fluoxetine decreases the depressive symptoms and the drinking of adolescents with comorbid major depression and an AUD. The authors conducted a 12-week open-label study of fluoxetine (20 mg) in 13 adolescents with current comorbid major depression and an AUD. A significant within-group decrease (improvement) was found for both depressive symptoms and drinking during the course of the study. The fluoxetine was well tolerated during the study. These data suggest promise for fluoxetine for decreasing both the depressive symptoms and the drinking of adolescents with comorbid major depression and an AUD.

Adolescent↗
PubMedDate not supplied

Alcohol consumption in university students: the role of reasons for drinking, coping strategies, expectancies, and personality traits.

Despite the popularity of the social learning perspective of alcohol abuse, there have been limited efforts devoted to developing comprehensive models that delineate the roles of the constituent components of this approach. In the present study, we determined whether reasons for drinking, coping strategies, alcohol expectancies, and personality traits predict binge drinking and alcohol consumption levels in university students. Escape drinking was the sole positive direct predictor of binge drinking. Social drinking predicted alcohol consumption and thereby exerted an indirect influence on binge drinking. Alcohol expectancies played a significant role in the model but only by influencing reasons for drinking. Although the use of alcohol and/or drugs to cope predicted alcohol consumption, none of a variety of other coping strategies exerted a significant influence in the model. Stress responsivity-related personality traits played a significant role, primarily via an influence on alcohol expectancies. These findings provide support for the social learning perspective of alcohol abuse and offer further insight into the factors that contribute to the development of risky alcohol consumption patterns.

Adaptation, Psychological↗
PubMedDate not supplied

Antimicrobial agents from higher plants. Antimicrobial isoflavanoids and related substances from Glycyrrhiza glabra L. var. typica.

Bioassay-directed fractionation of Glycyrrhiza glabra L. var. typica resulted in the isolation and characterization of glabridin (I), glabrol (2), glabrene (3), 3-hydroxyglabrol (4), 4'-O-methylglabridin (5), 3'-methoxyglabridin (6), formononetin (7), phaseollinisoflavan (8), hispaglabridin A (9), hispaglabridin B (13), salicylic acid and O-acetyl salicylic acid. Of these, hispaglabridin A, hispaglabridin B, 4'-O-methylglabridin, glabridin, glabrol and 3-hydroxyglabrol possess significant antimicrobial activity in vitro; hispaglabridin A, hispaglabridin B, 3'-methoxyglabridin, 4'-O-methylglabridin 3-hydroxyglabrol, phaseollinisoflavan, salicylic acid, and O, acetyl salicylic acid are newly found in Glycyrrhiza sp.; and hispaglabridin A, hispaglabridin B, 3'-methoxyglabridin, 4'-O-methylglabridin, and 3-hydroxyglabrol are new to the literature and their structures are proposed herein.

Anti-Infective Agents↗
PubMedDate not supplied

Modified mutagen metabolism in Schistosoma hematobium-infested organisms.

The relationship between parasite infestation and chemical mutagen metabolism was investigated in this study. Schistosoma hematobium, long associated with increased incidence of bladder cancer in humans, was chosen as a model parasite. Urine samples, serum samples, and liver tissue extracts (S-9) from infested and control hamsters were used with the Ames Salmonella/microsome test to follow 3,3'-dichlorobenzidine (DCB), aflatoxin B1 (AFB1), and 2-acetylaminofluorene (AAF) mutagenicity. Liver S-9 preparations from infested and control hamsters showed little difference in activation potential for DCB and AFB1. Aroclor 1254-induced rat liver S-9, however, was remarkably efficient at reducing the mutagenicity of DCB. This process was reversible by beta-glucuronidase (BG). Studies on infested and control hamsters indicated increased BG activity in serum and urine. Urine concentrates (UC) from infested and control animals were not mutagenic by themselves, but did enhance the mutagenicity of AAF and DCB in the presence of S-9 and BG. Urine concentrates from infested animals showed greater enhancement of DCB mutagenicity than did UC from control animals. These data suggest that increased BG and unknown urinary factors in infested hamsters play a role in altering chemical mutagen activity.

2-Acetylaminofluorene↗
PubMedDate not supplied

Effects of intact versus non-intact families on adolescent head injury rehabilitation.

Forty-one children, aged 8-18 years, were admitted to a comprehensive in-patient head injury rehabilitation facility over a 5-year period. Over half (59%) came from families with only one biological parent in the home. Data from intact versus non-intact families suggest that the children from the latter were significantly younger and remained as in-patients significantly longer than their counterparts. The severity of injuries and incidence of premorbid psychosocial documentation were equivalent for the two groups. The implications for treatment and future research are discussed. A previous version of this paper was presented at the 97th convention of the American Psychological Association in New Orleans on August 13, 1989. The authors are grateful to Dr Mark Ylvisaker for his comments and suggestions.

Adolescent↗
PubMedDate not supplied

Case report: Unusual location of Dirofilaria immitis in a 28-year-old man necessitates orchiectomy.

The fourth case of zoonotic Dirofilaria immitis infection in a California resident is reported. This case was unique in that it involved the spermatic cord, produced significant symptoms, and upon physical examination was suspected of being an incarcerated inguinal hernia. At surgery frozen sections were inconclusive regarding neoplasia and cord involvement precluded removal of the mass without orchiectomy, which was done. Histopathology revealed a well-preserved immature male D. immitis, the canine heartworm, in a branch of the spermatic artery. The morphological identification of the worm was confirmed by polymerase chain reaction (PCR) studies. This case illustrates that D. immitis infections can complicate differential diagnosis of extrapulmonary lesions and suggests that the public health significance of this vector-borne filarial worm needs to be evaluated through appropriate epidemiological studies in enzootic areas.

Adult↗
PubMedDate not supplied

Quantitative analysis of epidermal growth factor in human benign prostatic hyperplasia and prostatic carcinoma and its prognostic significance.

The incidence of prostatic carcinoma (PC) is increasing worldwide. Despite the discovery by Huggins in 1941 of the hormone dependency of this tumour, the overall prognosis and survival for patients with advanced disease has not changed. The prognosis for individual patients with PC cannot be accurately predicted by factors such as clinical stage and histological differentiation of the tumour. There is therefore a need to investigate new prognosis factors to assess their role.

Aged↗
PubMedDate not supplied

Antimicrobial agents from higher plants. An investigation of Hunnemannia fumariaefolia pseudoalcoholates of sanguinarine and chelerythrine.

The antimicrobial activity seen in extracts of Hunnemmania fumariaefolia S. resides in the alkaloids. The activity seen in the non-polar fractions had been shown by chromatography, physicochemical measurements, and comparisons with authentic samples to be due to apparently artifactual formation of the pseudomethanolates and pseudoethanolates of the alkaloids sanguinarine and chelerythrine, which are abundant in the plant. The enhanced potency of the pseudoalcoholates of sanguinarine over the parent benzophenanthridine is discussed in comparison with the in vitro biopotencies of other analogs prepared for the purpose. It appears that the pseudoalcoholates may be useful prodrugs.

Alcohols↗