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Biomedical subjects

A David

Publications and source records attributed to A David.

At least 145 records · Page 8Linked to original sources
PubMed1996

Statistical methods of estimation and inference for functional MR image analysis.

Two questions arising in the analysis of functional magnetic resonance imaging (fMRI) data acquired during periodic sensory stimulation are: i) how to measure the experimentally determined effect in fMRI time series; and ii) how to decide whether an apparent effect is significant. Our approach is first to fit a time series regression model, including sine and cosine terms at the (fundamental) frequency of experimental stimulation, by pseudogeneralized least squares (PGLS) at each pixel of an image. Sinusoidal modeling takes account of locally variable hemodynamic delay and dispersion, and PGLS fitting corrects for residual or endogenous autocorrelation in fMRI time series, to yield best unbiased estimates of the amplitudes of the sine and cosine terms at fundamental frequency; from these parameters the authors derive estimates of experimentally determined power and its standard error. Randomization testing is then used to create inferential brain activation maps (BAMs) of pixels significantly activated by the experimental stimulus. The methods are illustrated by application to data acquired from normal human subjects during periodic visual and auditory stimulation.

Acoustic Stimulation↗
PubMed1996

Coping strategies and psychiatric morbidity in women attending breast assessment clinics.

This study examined the role of coping strategies and personality characteristics in mediating psychiatric morbidity in subjects facing possibly serious breast disease. Participating were 121 women aged 20 to 65 undergoing breast fine needle biopsy for a suspicious lesion on mammography. All subjects received psychosocial assessments including the 12-item General Health Questionnaire (GHQ-12), the Eysenck Personality Inventory (EPI) and the Coping Strategies Inventory. The results show that neuroticism was the only EPI subscore significantly correlated with GHQ-12 score. A habitual method of coping with adversity known as 'engagement' has a negative correlation with GHQ-12 score; that is, patients who actively confront their illness and the uncertainty that surrounds it show better psychological health. Stepwise multiple regression reveals that neuroticism and an engagement coping strategy are the most significant predictors towards GHQ-12 score prior to the diagnosis of breast cancer.

Adaptation, Psychological↗
PubMed1996

Oral complaints related to menopause.

OBJECTIVES: The purpose of the present study was to correlate oral and systemic symptoms of menopause and the oral health and salivary composition and flow rate in a group of women in menopause prior to hormone replacement therapy. METHODS: One-hundred fifty-four women attending a menopause clinic were divided into two groups. Group A, 58 women, without any systemic disease or treatments, and Group B,96 women with diseases and on various medications. They answered a questionnaire on their general health and oral and systemic complaints related to menopause. Fifty-four of the women agreed to have an oral examination and saliva analysis. Whole resting and submandibular (SM-SL) stimulated saliva were analyzed. RESULTS: The oral discomfort complaint was found in 45% in Group A and in 60% in Group B. 74% complained of climacteric symptoms in Group A and 63% in Group B. The odds ratio (OR) between oral discomfort and climacterics complaints of menopause was 8.03 in Group A and 4.08 in Group B. The salivary composition and flow rates did not differ significantly between the groups of menopausal women. However the salivary total protein and IgA concentrations were significantly higher in comparison to healthy young controls. CONCLUSIONS: The present study reports a high prevalence of oral discomfort in the women attending a menopause clinic. A highly significant odds ratio between systemic and oral complaints of menopause was found. The significantly altered salivary composition in these women might point to sympathetic activation due to psychological stress.

Adult↗
PubMed1996

Psychosocial risk factors for chronic fatigue and chronic fatigue syndrome following presumed viral illness: a case-control study.

This study investigated psychosocial morbidity, coping styles and health locus of control in 64 cases with and without chronic fatigue identified from a cohort of primary care patients recruited 6 months previously with a presumed, clinically diagnosed viral illness. A significant association between chronic fatigue and psychosocial morbidity, somatic symptoms and escape-avoidance coping styles was shown. Chronic fatigue cases were significantly more likely to have a past psychiatric history and a current psychiatric diagnosis based on a standardized clinical interview. Twenty-three of the cases fulfilled criteria for chronic fatigue syndrome (CFS). Such cases were significantly more fatigued than those not fulfilling criteria, but had little excess psychiatric disorder. A principal components analysis provided some evidence for chronic fatigue being separable from general psychosocial morbidity but not from the tendency to have other somatic complaints. Past psychiatric history and psychological distress at the time of the viral illness were risk factors for psychiatric 'caseness' 6 months later, while presence of fatigue, psychologising attributional style and sick certification were significant risk factors for CFS. These findings extend a previous questionnaire study of predictors of chronic 'post-viral' fatigue.

Adaptation, Psychological↗
PubMed1996

Immobilization of flax protoplasts in agarose and alginate beads. Correlation between ionically bound cell-wall proteins and morphogenetic response.

Linum usitatissimum protoplast-derived colonies that are cultured in auxin-supplemented medium and immobilized in Ca(2+)-alginate matrix form round colonies that develop into polarized, embryo-like structures. On the other hand, protoplast-derived colonies that are immobilized in agarose do not show an organized morphogenetic response, and unique, ionically bound cell-wall protein patterns match this response. Although only slight differences in neosynthesized or total constitutive polypeptides are observed, dramatic changes in ionically bound cell-wall proteins are seen. In protoplasts grown on Ca(2+)-alginate-solidified, auxin-containing medium, several basic polypeptides were strongly induced and were found tightly bound to the cell wall. In contrast, these basic proteins were found only weakly bound to the walls of protoplasts grown on agarose-solidified, auxin-containing medium or on Ca(2+)-alginate-solidified, auxin-free medium, in which they were released into the medium. Our results suggest that plant cells can perceive and respond to the adjacent extracellular matrix, since we show that the growth of flax cells on Ca(2+)-alginate in the presence of auxin-containing medium may promote the binding of specific proteins to the walls. This establishes a direct correlation of an embryo-like morphogenesis with ionically bound cell-wall basic proteins in flax protoplasts grown on Ca(2+)-alginate-solidified, auxin-containing medium.

Alginates↗
PubMed1996

Nosology of fetal hypokinesia sequence based on CNS abnormalities: is there an Aase-Smith syndrome?

Aase-Smith syndrome (ASS) is usually defined as a dominantly inherited combination of arthrogryposis, Dandy-Walker malformation and cleft palate. We describe a sporadic case of foetal akinesia with abnormal fossa posterior, fitting the diagnosis of ASS, and discuss the nosology of this entity among syndromes with distal arthrogryposis. ASS shows a "hybrid" phenotype: adults with mild ASS could be classified as distal arthrogryposis, whereas severely affected newborns overlap with the Marden-Walker phenotype, which is recessively inherited. The specificity of the disorder comes from the coexistence of both forms in the same pedigree, so that ASS appears impossible to diagnose with certitude in sporadic cases. We suggest that the severe expression of ASS is only the extreme but aspecific expression of a dominantly inherited form of distal arthrogryposis. Implications for genetic counselling in distal arthrogryposis are outlined.

Abnormalities, Multiple↗
PubMed1996

Psychological predictors of insight and compliance in psychotic patients.

BACKGROUND: A possible neuropsychological basis for poor insight in psychosis has been proposed. Consistent supporting evidence for this is lacking. METHOD: Seventy-four consecutive acutely psychotic in-patients who were recruited for a randomised controlled trial of compliance therapy were given a battery of neuropsychological tests, along with a comprehensive clinical assessment, before and after the intervention. RESULTS: Performance on neuropsychological tests improved during the patients' admission and treatment in hospital, as did symptoms and levels of insight. Cognitive function showed no relationship to insight and compliance initially, and very little after the intervention. Factors related to insight and compliance prior to discharge included: diagnosis, attitudes to medication, side-effects, being a detained patient, and whether or not compliance therapy was given. CONCLUSIONS: Clinical variables and attitudes to treatment appear to be more relevant to compliance and the development of insight in acute psychosis than neuropsychological impairment.

Adolescent↗
PubMed1996

[Surgical treatment of ankle joint fractures with biodegradable screws and plates of poly-l-lactide].

In a first clinical protocol 19 ankle fractures have been fixed by plates and screws made of biodegradable polylactic acid. Fracture confirmation was achieved within 6 weeks. 52% of our patients demonstrated an aseptic soft tissue problem caused by delayed clearance of the degrading polylactide particles. In a 2nd protocol with 7 patients volume reduced plates and screws with flat heads were applied. None of these patients had any soft tissue reaction. These results emphasize that the application of plates and screws of polylactic acid is acceptable for fixation of ankle fractures. Soft tissue inflammatory reactions can be avoided by using volume reduced implants.

Adult↗
PubMed1996

Metastatic breast carcinoma manifesting as postmenopausal uterine bleeding in a patient on tamoxifen therapy.

A rare case of breast carcinoma metastasizing to the endometrial and endocervical mucosa during tamoxifen treatment is presented. Routine histologic evaluation has been supplemented by immunohistochemical staining for intermediate filaments. Although the association of tamoxifen therapy for breast carcinoma with the development of endometrial carcinoma is well known, this is, to the best of our knowledge, the first report of metastatic breast carcinoma to the uterus of a patient on tamoxifen therapy.

Aged↗
PubMed1996

[Perineal injuries in complicated pelvic trauma].

Severe comminuted pelvic ring fractures are often associated by genitourinary and rectal injuries. Because of severe retroperitoneal bleeding, shock management has to be initiated before further diagnosis of the perineal lesions. If normotonic conditions cannot be achieved by volume replacement, a pelvic clamp is indicated providing immediate reduction of the posterior pelvic ring. A subsequent emergency laparotomy has to be considered if stable circulatory conditions cannot be achieved by these emergency procedures. After the initial management of the hypovolemic shock further examination of the rectum by endoscopy and endosonography is performed. Urethral lesions have to be excluded by ultrasound of the bladder, retrograde urethrography and intravenous urography. Urethral and bladder injuries can be initially treated by suprapubic fistula, whereas rectal and pararectal wounds have to be managed by immediate debridement, jet-lavage and wound drainage. Rectal wall and sphincter lacerations are initially restored by suture because delayed reconstructions have poor results. A deviation colostomy is mandatory in cases of colonic and rectal injuries about the internal sphincter.

Colon↗
PubMed1995

Opitz GBBB syndrome: chromosomal evidence of an X-linked form.

BBB syndrome and G syndrome were originally reported as distinct X-linked disorders. Clinical studies indicated that BBB and G syndromes were likely to represent variant expression of the same disorder, now referred to as "Opitz" GBBB syndrome. Several occurrences of male-to-male transmission in both syndromes led to the hypothesis that GBBB syndrome was a single autosomal dominant, sex influenced disorder, now tentatively mapped to 5p12-13. We report on a large pedigree in which GBBB syndrome appears to cosegregate with a pericentric inversion of the X chromosome inv(X)(p22.3q26). It indicates the possible existence of a true X-linked form of GBBB syndrome, which does not appear phenotypically different from its autosomal counterpart. The gene could map in the vicinity of the breakpoints, in Xp or Xq. The existence of two genes affecting a common pathogenetic pathway could explain the gender-dependent expressivity of GBBB phenotype.

Abnormalities, Multiple↗
PubMed1995

Overuse of the indwelling urinary tract catheter in hospitalized medical patients.

BACKGROUND: The indwelling urinary tract catheter (IUTC) is an important aspect of medical care. We studied the prevalence of the unjustified use of the IUTC in hospitalized medical patients and identified situations associated with its unjustified use. METHODS: This prospective study involved 202 patients admitted to either the medical intensive care unit (n = 135) or the medical floors (n = 67) of a tertiary care university hospital who were catheterized during the hospital admission. An independent observer assessed the indication of initial catheterization by chart review and interview with the patient and the nurse. The need for continued catheterization was assessed daily by the same observer. The proportion of unjustified IUTC placement was determined using the study guidelines. Complications as a direct consequence of catheter use were recorded. RESULTS: Of the 202 patients who were studied, the initial indication for the placement of an IUTC was found to be unjustified in 21% (95% confidence interval [CI], 15% to 27%). Continued catheterization was unjustified in 47% (95% CI, 42% to 57%) of 912 patient-days with IUTC studied. In the medical intensive care unit, 64% (95% CI, 58% to 70%) of the total unjustified patient-days with IUTC resulted from its excessively prolonged use for monitoring urine output. Urinary incontinence was found to be the major cause of unjustified initial ([52%] 95% CI, 32% to 74%) and continued ([56%] 95% CI, 50% to 62%) use of IUTC in the noncritical care areas. Catheter-related urinary tract infection requiring intravenous antibiotics or continuous bladder irrigation with amphotericin B was observed in 5% of the patients. CONCLUSIONS: The IUTCs are significantly overused in hospitalized medical patients and careful attention to this aspect of medical care may reduce catheter-related complications by primary prevention.

Catheters, Indwelling↗
PubMed1995

Dominant mesomelic shortness of stature with acral synostoses, umbilical anomalies, and soft palate agenesis.

We report on a father and 2 children (a living 4-year-old girl and an aborted 18-week-old fetus) with a dominantly inherited form of mesomelic shortness of stature with severe ankle, knee, and elbow involvement. Skeletal abnormalities included brachymetacarpy and brachymetatarsy of the 3rd to 5th rays, synostoses in these bones, synostoses of metacarpals and metatarsals II to V with the corresponding carpal/tarsal bones, partial fusion in the proximal row of carpal bones, and mild vertebral anomalies. Father and daughter also had downslanted palpebral fissures, beaked nose, hypertelorism, ptosis, microretrognathia, and transverse agenesis of the soft palate. Abnormally short umbilical cord with unusually long skin coverage was present. Mesomelic shortness worsens with time, with progressive curvature of the forearm. This condition appears to represent a previously undescribed MCA/dysostosis syndrome.

Abnormalities, Multiple↗
PubMed1995

Laparoscopic resection of a large hepatic tumor.

Increasing experience among surgeons and a proliferation of endoscopic instrumentation have allowed a greater number of intraabdominal organs to be approached laparoscopically. Procedures once delegated to standard open technique are now attempted laparoscopically with increasing success. The following case report describes the laparoscopic removal of a large segment IV liver tumor. A review of the literature shows this to be one of the most complex hepatic lesions to be removed laparoscopically to date.

Adenoma↗