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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
PubMed2001

An outbreak of viral gastroenteritis in a mother-and-child health clinic.

An outbreak of diarrhoeal disease in a modern mother-and-child health clinic prompted the health authorities to initiate a retrospective cohort study in order to assess the scope of the outbreak and to identify possible risk factors. The management of the clinic had been rather concerned because four similar outbreaks had occurred during the last two years. A total of 151 guests, i.e. mothers with their children, who had arrived some days before the peak of the outbreak for a three-week-stay and another 15 guests who had arrived earlier and had extended their stay were enrolled in the study which mainly focused on the possible role of treatment measures as risk factors. In addition, a total of 49 staff members were requested to provide information about symptoms, working area and attendance at work. Relevant data were available from 164 of 166 guests and 47 of 49 staff members (response rates 98.8% and 96.0%, respectively). The attack rate among guests was 44.0% (adults 27.0%, children 54.0%) and among staff 23.4%. The mean age of affected children (3.5 years) was significantly lower than that of those not affected (6.3 years). The main symptoms were diarrhoea and vomiting. The sudden start of the outbreak suggested a single source of infection which, however, remained unknown. Person-to-person transmission was supposed to be the cause of the following spread. No association between distinct treatment measures and the disease was proven by the cohort study. Norwalk-like viruses as well as astroviruses were detected by polymerase chain reaction in specimens taken from seven patients. No other enteropathogenic agents were found. Regarding the special conditions in a mother-and-child health clinic where social contacts among guests are much more frequent and intensive than among patients in a "normal" hospital, measures to prevent the spread of gastrointestinal infections should concentrate on early recognition and isolation of symptomatic individuals. Guests and staff members should be instructed to keep to the rules of personal hygiene, especially handwashing. If disinfection is required, it should be virucidal.

Adolescent↗
PubMed2001

Psychophysiological responses in ADHD boys with and without conduct disorder: implications for adult antisocial behavior.

OBJECTIVE: Several studies have demonstrated that the presence of attention-deficit/hyperactivity disorder (ADHD) in childhood increases the risk of antisocial behavior developing in adulthood. However, because previous research did not consider comorbid conduct disorder (CD), the question of whether ADHD by itself or only the association of ADHD with CD implies a risk of adult antisocial behavior developing is still under discussion. METHOD: Because several characteristics of psychophysiological response had been shown to be associated with future increased likelihood of adult antisocial behavior, autonomic arousal as well as electrodermal responses to orienting and aversive stimuli were assessed in 26 boys with ADHD+CD compared with 21 boys with ADHD alone and 21 controls. RESULTS: Boys with a comorbid condition of ADHD+CD showed a decrement of autonomic responses and a more rapid habituation to orienting and aversive startling stimuli compared with age-matched children with ADHD alone. CONCLUSIONS: Boys with ADHD+CD show a psychophysiological response pattern that is very similar to that reported in antisocial personalities. These findings give further support for a high persistence of antisocial behavior from childhood to adulthood, while no evidence was found that ADHD itself is associated with a predisposition to antisocial behavior.

Adolescent↗
PubMed2001

Thalidomide in gastrointestinal disorders.

Thalidomide was originally marketed as a sedative, but was removed from the market in 1961 after it was associated with an epidemic of severe birth defects. Subsequently, it has been shown to have therapeutic efficacy in a number of the gastrointestinal tract conditions characterised by immune dysregulation. The exact mechanism of the immunosuppressive effects of thalidomide is unknown; proposed mechanisms include inhibition of tumour necrosis factor alpha release and inhibition of angiogenesis. In chronic graft versus host disease, use of high dose thalidomide (1200 mg/day) may bring about a response in 20% of patients with refractory disease. Thalidomide 200 mg/day helps eradicate ulcers in 50% of patients with HIV-associated oral aphthous ulceration. In Behçet's disease, thalidomide 100 to 300 mg/day can decrease the number of mucocutaneous ulcers, although full remission occurs in less than 20% of patients. In Crohn's disease, thalidomide 50 to 300 mg/day may decrease the severity of mucosal disease and prompt closure of fistulae. Patients to be placed on thalidomide therapy must practice either abstinence or strict birth control; women must undergo regular pregnancy testing and utilise 2 forms of contraception. Other adverse effects include sedation (present in nearly all patients), symptomatic neuropathy (present in approximately 20%), and skin rashes. Given the potential toxicity, thalidomide use should generally be limited to clinical protocols with institutional review board oversight.

Behcet Syndrome↗
PubMed2000

Strange magnetism and the anapole structure of the proton.

The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The measurement reported here provides an unambiguous constraint on strange quark contributions to the proton's magnetic moment through the electron-proton weak interaction. We also report evidence for the existence of a parity-violating electromagnetic effect known as the anapole moment of the proton. The proton's anapole moment is not yet well understood theoretically, but it could have important implications for precision weak interaction studies in atomic systems such as cesium.

Journal Article↗
PubMed2000

[What you always wanted to know about HbA1c].

Irreversible, nonenzymatic glycation of the haemoglobin A beta chain leads to the formation of haemoglobin A1c (HbA1c), a stable minor haemoglobin component with enhanced electrophoretic mobility. The rate of formation of HbA1c is directly proportional to the ambient glucose concentration. HbA1c is commonly used to assess long-term blood glucose control in patients with diabetes mellitus, because the HbA1c value has been shown to predict the risk for the development of many of the chronic complications in diabetes. There are currently four principal glycohaemoglobin assay techniques (ion-exchange chromatography, electrophoresis, affinity chromatography and immunoassays) and over 20 methods that measure different glycated products. The ranges indicating good and poor glycaemic control can vary markedly between different assays. At the moment values differ between methodologies and even between different laboratories using the same methodology. Optimal use of HbA1c testing requires standardisation. There is progress towards international standardisation and improved precision of HbA1c which will lead to all assays reporting results in a standardised way. Clinicians ordering HbA1c testing for their patients should be aware of the type of assay method used, the reference interval, potential assay interferences (e.g. haemoglobinopathies, chronic alcohol ingestion, carbamylation products in uraemia) and assay performance. And they should know that a variety of factors have been shown to directly influence HbA1c values, e.g. iron deficiency anaemia, chronic renal failure and shortened red blood cell life span.

Anemia, Iron-Deficiency↗
PubMed2000

Interaction within clusters of dendritic cells and helper T cells during initial Th1/Th2 commitment.

Cytokines are the main agents known to regulate Th1 / Th2 commitment, where they may operate through paracrine activity within clusters of T cells gathered around dendritic cells (DC). An in vitro system is used here to test this possibility, using clusters around DC composed of naive TCR-transgenic ovalbumin peptide 323 - 339-specific CD4(+) T cells as targets plus TCR-transgenic pigeon cytochrome C peptide 88 - 104-specific CD4(+) polarized Th1 or Th2 cells as inducers. The polarized inducer cells exerted their maximum effect when the two T cell populations were activated within the same cluster, implemented by allowing a single DC to present both their epitopes. This finding thus supports the paracrine hypothesis. The system was then employed to explore the role of individual cytokines by means of inhibition by monoclonal antibodies. Development of Th2 commitment proved strictly dependent on the IL-4 produced by the Th2 inducers. For Th1 commitment, IFN-gamma and IL-12 were both needed, but with IFN-gamma required only during the initial period of culture. The rapid timing observed under these conditions places constraints on the molecular basis of commitment, and appears accurately to reflect the physiological response in vivo.

Animals↗
PubMed2000

Chondral lesions after arthroscopic meniscus repair using meniscus arrows.

Meniscus repair using bioabsorbable devices has become popular in the last few years. Good clinical results have been reported and few complications have been published. This report describes the case of a 37-year-old male patient with a lateral meniscus repair using 4 Meniscus Arrows (Bionx Implants, Blue Bell, PA). Postoperatively, repeated episodes of intra-articular effusions have occurred. A second-look arthroscopy 8 months after the reconstruction showed that the meniscus tear had not healed and revealed the presence of chondral damage corresponding to the location of the arrows in the posterior area of the lateral femoral condyle. Surgeons using the Meniscus Arrow should be aware of this possible postoperative complication.

Absorbable Implants↗
PubMed2000

Angiogenesis in cutaneous lymphoproliferative disorders: microvessel density discriminates between cutaneous B-cell lymphomas and B-cell pseudolymphomas.

The role of angiogenesis in neoplastic disorders is supported by the evidence that tumor growth beyond a certain size requires induction of new blood vessels. The extent of tumor-associated angiogenesis, measured as microvessel density (MVD), has shown to correlate with aggressiveness and the prognostic outcome in several malignant neoplasms. Few data have been reported on the angiogenic response in lymphoproliferative diseases. In this study, the MVD has been assessed in benign and malignant primary cutaneous B-cell lymphoproliferative disorders. MVD was determined in formaldehyde-fixed, paraffin-embedded specimens of primary cutaneous B-cell lymphomas (CBCL; n = 18) and cutaneous B-cell pseudolymphomas (B-PSL; n = 22) according to previously described protocols but was performed using computer-aided microscopic morphometry. The endothelial cells of microvessels were identified by immunohistochemical staining for factor VIII-related antigen and CD31. The MVD was 99 dots/mm2 for CBCL and 68 dots/mm2 for PSL, and a MVD of 115 dots/mm2 for CBCL and 73 dots/mm2 for PSL by using an antibody against factor VIII-related antigen and CD31 antigen, respectively. Univariate analysis revealed statistically highly significant differences in MVD between CBCL and B-PSL (P = 0.0036 with staining for factor VIII-related antigen and P = 0.0002 with staining for CD31 antigen). This study analyzes for the first time the angiogenic response in CBCL compared with that of B-PSL and demonstrates that MVD discriminates between CBCL and B-PSL. However, because of an overlap in the ranges of MVD in CBCL and PSL, the MVD is not useful as a diagnostic tool in individual cases.

Blood Vessels↗
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↗