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Biomedical subjects

B Mueller

Publications and source records attributed to B Mueller.

At least 37 records · Page 2Linked to original sources
PubMed2000

Measuring symptom distress in patients with lung cancer. A pilot study of experienced intensity and importance of symptoms.

Patients with cancer experience high levels of symptom distress. Current measures of symptoms generally weight the importance of each symptom equally, and do not generally address the relative importance of different symptoms to patients. The purpose of this pilot study was to explore whether the assumption of equal weighting is warranted in measurements of symptom distress. Consecutive patients presenting with primary lung cancer at the Lung Medicine Unit of one Swedish hospital completed the Symptom Distress Scale and a Thurstone scale eliciting patients' weightings of the symptoms' relative importance three times: after first contact with the unit, then 1 and 2 months later. The results show that subjects weighted some symptoms as significantly more important than others, and the ordering of symptoms was found to differ by intensity and perceived importance in this group. Outlook was the symptom rated most important at T1. Fatigue received the highest intensity score, but ranked second lowest in importance. Kendall's coefficient showed minimal agreement among these patients as to the specific order for the weighting of the importance of symptoms. In addition to theoretical relevance, this issue is clinically relevant in selecting symptoms that should be the focus of intervention and in determining how the success of interventions should be judged.

Aged↗
PubMed1999

PTEN modulates cell cycle progression and cell survival by regulating phosphatidylinositol 3,4,5,-trisphosphate and Akt/protein kinase B signaling pathway.

To investigate the molecular basis of PTEN-mediated tumor suppression, we introduced a null mutation into the mouse Pten gene by homologous recombination in embryonic stem (ES) cells. Pten-/- ES cells exhibited an increased growth rate and proliferated even in the absence of serum. ES cells lacking PTEN function also displayed advanced entry into S phase. This accelerated G1/S transition was accompanied by down-regulation of p27(KIP1), a major inhibitor for G1 cyclin-dependent kinases. Inactivation of PTEN in ES cells and in embryonic fibroblasts resulted in elevated levels of phosphatidylinositol 3,4,5,-trisphosphate, a product of phosphatidylinositol 3 kinase. Consequently, PTEN deficiency led to dosage-dependent increases in phosphorylation and activation of Akt/protein kinase B, a well-characterized target of the phosphatidylinositol 3 kinase signaling pathway. Akt activation increased Bad phosphorylation and promoted Pten-/- cell survival. Our studies suggest that PTEN regulates the phosphatidylinositol 3,4, 5,-trisphosphate and Akt signaling pathway and consequently modulates two critical cellular processes: cell cycle progression and cell survival.

Animals↗
PubMed1999

[ABC of thyroid diseases and their treatment].

Thyroid diseases are caused by a disturbance of thyroid hormone secretion, inflammations or tumors of the thyroid or combinations thereof. Most important causes for hyperthyroidism are Graves' disease and toxic nodular goiters (including toxic adenomas). Hypothyroidism is often caused by Hashimoto's chronic thyroiditis and can occur in patients after thyroidectomy. Chronic hashimoto's thyroiditis and subacute de Quervain's thyroiditis are the thyroid inflammations most frequently seen. Graves' disease and Hashimoto's thyroiditis are autoimmune thyroid diseases. Thyroid tumors encompass benign solitary nodules, diffuse and nodular goiters, papillary, follicular, medullary and anaplastic carcinomas.

Diagnosis, Differential↗
PubMed1999

[Goiter and nodular thyroid disease: clinical guidelines for diagnosis and treatment. (Waiting? Hormone therapy? Surgery? radioiodine?)].

Nodular thyroid disease is a common problem. We present clinical guidelines for the management of patients with thyroid nodules, multinodular goiters and thyroid cysts for use by primary physicians. In the initial evaluation ultrasonography of the thyroid and fine-needle aspiration biopsy (FNAB) is recommended. FNAB has become the cornerstone in the evaluation of solitary thyroid nodules, cysts and dominant nodules within multinodular goiters. If the procedure is done properly, it should have a false-negative rate of less than 5% and a false-positive rate of not more than 1%. Thyroid radionuclide scans are less frequently used in the initial evaluation of a nodular goiter. Surgery is the primary therapy for patients with nodular thyroid disease. Other available treatment options are radioiodine and TSH-suppression with thyroxine. The main indications for surgery in euthyroid patients with thyroid nodule or with nontoxic multinodular goiter are recently documented or suspected malignancy, compression of the trachea and esophagus, significant growth of the nodule, recurrence of a cyst after aspiration, neck discomfort and cosmetic concern.

Algorithms↗
PubMed1999

SEARCH international case-control study of childhood brain tumours: role of index pregnancy and birth, and mother's reproductive history.

A series of co-ordinated population-based case-control studies of childhood brain tumours (CBT) was undertaken under the auspices of the Surveillance of Environmental Aspects Related to Cancer in Humans (SEARCH) programme of the International Agency for Research on Cancer (IARC) to evaluate, inter alia, the risk in relation to characteristics of the index pregnancy and birth, and maternal reproductive history. Subjects comprised 1218 cases aged 0-19 years and 2223 controls. Risk estimates were calculated by unconditional logistic regression, adjusted for age, sex, centre and mother's years of schooling, for all types of CBT combined as well as for four groups defined by histopathology (astrologlial tumours, primitive neuroectodermal tumours of the brain, 'other glial' tumours and 'other histological types') and for five age groups (0-1, 0-4, 5-9, 10-14, 15-19 years). Use of anaesthetic 'gas' was associated with an increased risk of CBT (OR = 1.5, 95% CI [1.1, 2.0]), apparent in children aged 0-4 years (OR = 2.4, 95% CI [1.4, 4.1]) and for astroglial tumours (OR = 1.6, 95% CI [1.1, 2.2]) with non-significantly increased relative risks for each of the other histological groups. However, not all centre-specific relative risks were elevated. No other aspect of the index pregnancy, delivery and early neonatal period or of the mother's previous reproductive history was associated with risk for CBT.

Adolescent↗
PubMed1999

Human herpesvirus 8 (HHV-8) in familial Kaposi's sarcoma.

Human herpesvirus 8 (HHV-8) has been detected in various epidemiological forms of Kaposi's sarcoma (KS). Since familial KS cases are exceedingly rare and the occurrence of familial KS in siblings has thought to depend rather on genetic factors than on a viral factor, familial KS has not been investigated for the presence of HHV-8. To investigate whether HHV-8 is present also in this rare form of KS, we examined tumor biopsies of 2 siblings with familial KS for the presence of HHV-8 specific DNA sequences by a nested PCR protocol. HHV-8 DNA sequences could be detected in KS specimens of both patients. Sequence analysis revealed an identical DNA sequence of HHV-8 in KS tissue of both siblings, but the sequence in our cases differs in one base pair at position 67 from the previously published HHV-8 KS330Bam fragment. The findings indicate that besides the yet poorly defined genetical factors involved in the pathogenesis of KS, HHV-8 may act as a cofactor also in familial KS. In addition, our data demonstrate that HHV-8 is found in all epidemiological forms of KS, including the rarely occurring familial KS. Familial KS may act as a further model to study the interaction of an oncogenic virus with genetic host factors in the context of a neoplastic disorder.

Aged↗
PubMed1999

Preferences for participation in treatment decision making and information needs of parents of children with cancer: a pilot study.

This study was performed to obtain information on parents of children with cancer: (a) what role parents preferred to assume in treatment decision making (TDM); (b) parents' priority information needs; (c) if a relationship existed between TDM preferences and information needs; and (d) if sociodemographic, disease and treatment variables predicted TDM preferences or information needs. A cross-sectional survey was conducted with a convenience sample of 58 parents who had a child less than 13 years of age diagnosed with cancer in the previous year. Instruments included a Sociodemographic, Disease, and Treatment Questionnaire; the Control Preferences Scale for Pediatrics, and an Information Needs Questionnaire. The results showed that parents had systematic preferences about TDM, preferring collaborative followed by passive and active roles. Nine priorities in information needs (highest to lowest) were found: (a) treatments and tests, (b) cure, (c) caring for my child, (d) emotional impact, (e) side effects, (f) physical impact, (g) disease, (h) coping with painful procedures, and (i) impact on the family. Sociodemographic, disease and treatment variables were not predictive of preferences for TDM or information needs. Concrete informational needs take precedence over issues of emotional or family impact or pain. A low Kendall's coefficient (0.07) indicated that parents as a group do not have uniform information needs. Information giving must be individualized.

Adult↗
PubMed1999

Measuring the care needs of mothers of children with cancer: development of the FIN-PED.

This 2-phase study tested the Family Inventory of Needs-Pediatrics (FIN-PED), a 52-item instrument structured to include 2 subscales, the first measuring the importance of care needs and the second measuring the extent to which needs were met. In Phase I, an expert panel of 6 mothers of children with cancer rated the tool for clarity, apparent internal consistency, and content validity. All items met preset criteria for these assessments. In Phase II, 110 mothers rated the instrument for internal consistency reliability, stability over time, and internal construct validity. Both subscales achieved an estimated internal consistency of 0.94. Evidence of the instrument's stability over time was also achieved. Factor analysis resulted in 4 interpretable factors, suggesting that the tool is multidimensional.

Adolescent↗
PubMed1998

Experts and gold standards in dermatopathology: qualitative and quantitative analysis of the self-assessment slide seminar at the 17th colloquium of the International Society of Dermatopathology.

The diagnosis of lymphoproliferative and melanocytic skin lesions is one of the most vexing problems in dermatopathology, a problem that is compounded by the far-reaching therapeutic and psychosocial consequences of the diagnosis for both patient and physician. On the occasion of a self-assessment slide seminar held during a dermatopathology meeting, 30 unusual lymphoproliferative and melanocytic lesions, each provided with four differential diagnoses, were evaluated by "expert pathologists" and other participants ("nonexperts") of the slide seminar. The final diagnosis was pinpointed by the majority of the experts in 16 of 30 cases (56%). The group of experts returned an unanimous decision on the diagnosis in only 2 of the 30 cases (7%). In contrast to the expert group, the preferred diagnoses given by the nonexperts showed a wider range. In 20 of 30 cases (66%), the final diagnosis could only be established after consideration of clinical, histologic, immunophenotypic, and molecular features. Our findings agree with the results of recent studies indicating quite a high degree of discordance among expert pathologists. The discordance between experts and, to a higher extent, nonexperts may have some crucial consequences for dermatopathology. Full agreement on diagnosis, particularly in unusual skin lesions, cannot be achieved only by an accumulation of expertises. Instead of relying on one single finding or diagnostic procedure ("gold standard") as the main criterion upon which to base a diagnosis, the diagnoses become more reliable if based on the integration of several factors including an evaluation of clinical and histomorphologic features and immunophenotypic and molecular findings ("diagnostic elements"), particularly in the field of lymphoproliferative and melanocytic lesions. In addition, a continuous retrospective work-up of difficult or unusual cases is recommended to ensure a long-term improvement in diagnostic reliability.

Biomarkers↗
PubMed1998

Predicting the mechanical outcome of femoral neck fractures fixed with cancellous screws: an in vivo study.

OBJECTIVE: The goal of this project was to determine, by using a retrospective cohort analysis, the relative importance of fracture geometry, bone density, and quality of fracture reduction in predicting redisplacement of femoral neck fractures fixed with multiple cancellous screws in a patient population. DESIGN: A retrospective analysis of quantitative geometric and bone density data from forty-seven patients with femoral neck fractures fixed with cancellous screws was performed. SETTING: Radiographs retrieved after analysis of a statewide hospital database were digitized and analyzed quantitatively. INTERVENTION: Quantitative data from radiographs included estimates of femoral neck bone density, fracture surface orientation and location, degree of comminution, prefixation displacement, initial reduction position of the fractured component, and final displacement of the fracture after fixation. MAIN OUTCOME MEASUREMENTS: Angular rotation and inferior displacement of the fracture component after fixation. RESULTS: Femoral neck bone density can be correlated to femoral cortical thickness and can be used as a measure of bone density from plain x-rays. Significant relative risk of redisplacement of a femoral neck fracture is correlated with initial inferior offset of the fracture component and varus angulation. Relative risks of other variables, including valgus reduction, Garden Stage 3 and 4 position of the femoral head, low bone density, presence of inferior comminution, a more vertical fracture surface angle, and fracture position, were not significant. CONCLUSIONS: When compared with other geometric and mechanical variables, nonanatomic reduction of a femoral neck fracture, with either inferior offset or varus angulation, is the strongest predictor of postfixation redisplacement of the fracture.

Absorptiometry, Photon↗
PubMed1998

Development of a scale to measure information needs in cancer care.

Developing approaches to improve the use of scarce health care resources is of increasing importance in cancer care. Being able to target the provision of information to the primary needs of consumers ensures more productive use of expensive teaching time by health care professionals. Researchers and clinicians have used a variety of measurement techniques to assess the information needs of individuals with cancer at various points in their illness trajectory. The two most common types of scaling techniques used by researchers to measure information needs have been summative and differential. The advantages and disadvantages of using these types of measurements are evaluated. This article describes the development and pilot testing of a measure of the information needs in cancer patients that uses one type of differential scaling technique, Thurstone scaling. This measure was subsequently converted into a patient-friendly computerized program capable of helping consumers identify their information priorities before their medical visits. Individualized teaching may be guided by this new measurement technique in the future.

Breast Neoplasms↗
PubMed1998

[Guidelines for the evaluation of internal quality control of smears for screening of uterine cancer in France in the structures of Pathologic Anatomy and Cytology. French Association for Quality Assurance in Pathologic Anatomy and Cytology (AFAQAP)--Commission for cervical smears].

A national organized mass-screening effective programme is the only way to reduce the risk of cervical cancer, if properly organized and correlated with a system of Quality Assurance. Since 1900, an Association for Quality Assurance was created by the French pathologists, named "AFAQAP". These pathologists thus demonstrated their interest in this kind of action that should be effective if women and clinicians are also implied. The pathologists have concluded the first part of their programme with these French guidelines for internal quality control of pap smears.

Female↗
PubMed1998

Prevalence, morphology and biology of renal cell carcinoma in von Hippel-Lindau disease compared to sporadic renal cell carcinoma.

PURPOSE: Renal cell carcinoma occurs as a sporadic tumor but may be part of the autosomal dominant von Hippel-Lindau disease, characterized by retinal and central nervous system hemangioblastoma, pheochromocytoma, pancreatic cysts and renal cell carcinoma. We determine the prevalence of von Hippel-Lindau disease in a series of unselected renal cell carcinoma cases by molecular genetic analysis, and compare sporadic to von Hippel-Lindau renal cell carcinoma with respect to morphology and biology. MATERIALS AND METHODS: We established registers comprising 63 subjects with von Hippel-Lindau renal cell carcinoma, belonging to 30 distinct families (register A), and 460 unselected patients operated on for renal cell carcinoma in an 11-year period (register B). Molecular genetic analysis of the von Hippel-Lindau gene was performed for living patients of register A, representing 80% of von Hippel-Lindau families, and register B, 62% living patients, to identify von Hippel-Lindau germline mutations. In addition, register B was evaluated by a questionnaire (95% response) for familial occurrence of von Hippel-Lindau disease. RESULTS: The prevalence of von Hippel-Lindau renal cell carcinoma was 1.6% in 189 consenting unselected renal cell carcinoma patients. Risk factors for occult germline von Hippel-Lindau gene mutations in register B included familial renal cell carcinoma in 3 of 3 patients (100%), multifocal or bilateral renal cell carcinoma in 1 of 10 (10%) and age younger than 50 years at diagnosis in 1 of 33 (3%). Compared to sporadic von Hippel-Lindau renal cell carcinoma was characterized by an occurrence 25 years earlier, association with renal cysts, multifocal and bilateral tumors, cystic organization and low grade histology, and a better 10-year survival (p < 0.001 each). In von Hippel-Lindau disease metastases occurred only in tumors larger than 7 cm. CONCLUSIONS: von Hippel-Lindau differs from sporadic renal cell carcinoma in morphology and biology. Our data provide arguments for planning surgery for von Hippel-Lindau renal cell carcinoma and should stimulate future investigations.

Adult↗
PubMed1997

Information needs and decisional preferences in women with breast cancer.

OBJECTIVE: To determine the degree of involvement women with breast cancer wanted in medical decision making, extent to which they believed they had achieved their preferred level of involvement, and types of information they judged to be most important. DESIGN AND SETTING: Cross-sectional survey at 2 tertiary oncology referral clinics and 2 community hospital oncology clinics in Winnipeg, Manitoba. PATIENTS: Consecutive sample of 1012 women with a confirmed diagnosis of breast cancer who were scheduled for a visit at 1 of 4 hospital oncology clinics. MAIN OUTCOME MEASURES: The following measures were used: (1) Preferences about various levels of participation in treatment decision making; (2) the extent to which subjects believed they had achieved their preferred levels of involvement in decision making; and (3) priority needs for information and how these needs differed by selected sociodemographic, disease, and treatment variables. RESULTS: A total of 22% of women wanted to select their own cancer treatment, 44% wanted to select their treatment collaboratively with their physicians, and 34% wanted to delegate this responsibility to their physicians. Only 42% of women believed they had achieved their preferred level of control in decision making. The 2 most highly ranked types of information were related to knowing about chances of cure and spread of disease. Women younger than 50 years rated information about physical and sexual attractiveness as more important than did older women (P<.001); women older than 70 years rated information about self-care as more important than did younger women (P=.002); and women who had a positive family history of breast cancer rated information about family risk as more important than did other women (P=.03). CONCLUSIONS: The substantial discrepancy between women's preferred and attained levels of involvement in treatment decision making suggests that systematic approaches to assess and respond to women's desired level of participation in treatment decision making need to be evaluated. Priorities for information identified in this study provide an empirical basis to guide communication with women seeking care for breast cancer.

Adult↗
PubMed1997

Effects of continuous venovenous hemofiltration on cardiopulmonary function in a porcine model of endotoxin-induced shock.

OBJECTIVE: To determine whether continuous venovenous hemofiltration, proposed to remove inflammatory mediators from circulation, would resolve cardiopulmonary derangements in a model of established endotoxic shock. ANIMALS: 16 clinically normal pigs. PROCEDURE: Endotoxin was infused, IV, into anesthetized pigs for a total of 50 minutes. Thirty minutes after termination of the infusion period, extracorporeal circulation was initiated through a 50-kd diafilter, or past the filter without ultrafiltrate formation. Cardiac and respiratory variables were monitored for a period of 4 hours. RESULTS: Infusion of lipopolysaccharide resulted in a severe hypodynamic circulatory state, with significant decreases in mean arterial pressure and cardiac output concurrent with a significant increase in pulmonary arterial pressure. Hemofiltration was not associated with any correction of lipopolysaccharide-induced cardiopulmonary derangements. CONCLUSIONS: Continuous venovenous hemofiltration, as used in this acute experiment, did not improve cardiopulmonary dysfunction during endotoxic shock. CLINICAL RELEVANCE: Continuous venovenous hemofiltration needs further investigation before it can be recommended as a clinically effective treatment.

Animals↗
PubMed1997

Family members' care expectations, care perceptions, and satisfaction with advanced cancer care: results of a multi-site pilot study.

Psychometric properties of assessment tools designed for use with English-speaking family members of advanced cancer patients in different care settings and different geographic locations were evaluated in this study. The robustness of the theoretical framework guiding the study and the factors identified with care satisfaction were also tested. Seventy-two family members drawn equally from medical hospital units, palliative care units, and home care programs in Alberta, Saskatchewan, and Manitoba participated. Instruments used included the F-Care Expectations Scale, F-Care Perceptions Scale, FAMCARE Scale, and the General Functioning Scale of the Family Assessment Device. All four tools yielded acceptable reliability estimates. Discrepancy theory predicted family care satisfaction in a highly significant manner (p < 0.0001). Family members of patients who had been diagnosed for longer than two years had more positive perceptions of palliative care than did family members of patients diagnosed for less than two years (p = 0.05). Older family members reported better family functioning than younger family members (p < 0.001). Spouses reported less discrepancy between care expectations and perceptions than did other relatives (p < 0.05).

Aged↗