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Biomedical subjects

T Mayer

Publications and source records attributed to T Mayer.

At least 19 recordsLinked to original sources
PubMed2006

Occurrence of alkylphenolic substances in a Great Lakes coastal marsh, Cootes Paradise, ON, Canada.

Occurrence and fate of alkylphenols (APs), known endocrine disruptors, were investigated in a Great Lakes coastal wetland, Cootes Paradise, ON. The wetland, which receives discharges from a Wastewater Treatment Plant (WTP) and several Combined Sewer Overflows (CSOs), is an important spawning ground for fish and crucial habitat for other fauna. Elevated concentrations of nonylphenol ethoxylates (NPEs) and their degradation product nonylphenol (NP) were found in water and sediment samples near the sources. Since transfer of APs through the food chain is of concern, we compared their concentrations in invertebrates from clean and contaminated sites. The results reveal transfer of alkylphenolics from sediments to biota and their accumulation in the invertebrate tissue, particularly the highly hydrophobic 4-NP, whose concentrations ranged from 1.9 to 6.3 microg g(-1). To our knowledge, this is the first study to evaluate AP concentrations in tissue of benthic invertebrates under real environmental conditions.

Animals↗
PubMed2005

Laparoscopic treatment of gastroduodenal perforations: comparison with conventional surgery.

BACKGROUND: Laparoscopic techniques have been proposed as an alternative to open surgery for the treatment of peptic ulcer perforation. This study compared the outcome of laparoscopic and open approaches for the repair of gastroduodenal perforations. METHODS: A retrospective review was conducted with 134 consecutive patients treated for gastroduodenal perforations. These patients included 122 with perforated duodenal ulcers, 10 with perforated gastric ulcers, and 2 with iatrogenic duodenal perforations. Whereas 68 patients were treated laparoscopically, 66 patients underwent conventional (open) surgery. RESULTS: Laparoscopic repair was successful in 65 cases (96 %). The mean operating time was shorter with the laparoscopic technique (68 vs 59 min), but the difference was not significant. The duration of postoperative nasogastric aspiration and time to resumed oral intake were shorter in the laparoscopic group (2.6 vs 4.1 days and 4.4 vs. 5.2 days, respectively; p = 0.043). The postoperative analgetic requirements, and overall complications rate were significantly lower after laparoscopic surgery (p = 0.03 and p = 0.004, respectively). There was no statistically significant difference in hospital stay (5.1 vs 6.1 days) or mortality rate between the two procedures. CONCLUSION: Laparoscopic repair of gastroduodenal perforations is a safe alternative treatment offering certain significant short-term advantages.

Adolescent↗
PubMed2005

Amylin peptide levels are raised in infants of diabetic mothers.

BACKGROUND: Amylin is a novel 37 amino acid peptide hormone that is co-secreted with insulin from the pancreas in response to food intake. As a potent inhibitor of gastric emptying it plays an important role in the control of carbohydrate absorption. Feed intolerance is common in infants of diabetic mothers (IDM). AIMS: To establish a normal range of amylin levels in healthy neonates, and to determine whether serum amylin levels are raised in IDM. METHODS: A serial sample of 221 infants > or =28 weeks gestation was enrolled prior to delivery over a 12 month period. Blood samples collected immediately after birth (umbilical cord), and at the routine Guthrie test were analysed for amylin and insulin levels. RESULTS: Amylin levels in umbilical cord (n = 181) and Guthrie samples (n = 33) of healthy infants were 5.7 (3.0-9.1) and 6.9 (2.9-9.0) pmol/l respectively. IDM had significantly raised amylin levels in both cord (n = 31; 32.7 pmol/l, 25.9-48.1) and Guthrie samples (n = 8; 18.1 pmol/l, 15.3-23.6). Amylin correlated positively with insulin (n = 42; r = 0.67; 95% CI 0.4 to 0.81), birth weight (r = 0.22; 95% CI 0.08 to 0.36), and gestation (r = 0.18; 95% CI 0.03 to 0.32). Umbilical cord venous amylin levels showed agreement with arterial cord amylin levels (n = 34, mean bias -0.2, 95% CI 3.1 to -3.6). CONCLUSIONS: Amylin levels are significantly increased in the umbilical cord and Guthrie blood samples in IDM.

Amyloid↗
PubMed2004

Congested residual nidus after preoperative intranidal embolization in midsize cerebral arteriovenous malformations of 3-6 cm in diameter.

BACKGROUND: Modern delicate microcatheters allow intranidal embolization of cerebral arteriovenous malformations (AVM). The aim of the current analysis was to assess effects of preoperative intranidal deployment of embolic material on surgical time and blood loss in cerebral arteriovenous malformations of 3-6 cm in diameter. METHODS: The case records of 38 cerebral AVM between 3 and 6 cm in maximum diameter were reviewed, that had been embolized intranidally with N-butyl 2-cyanoacrylate (Histacryl) and subsequently operated on. Surgical time and blood loss as well as particular intraoperative findings such as a congested nidus and thrombosis of draining veins were registered and correlated with the extent of embolization and the time interval between embolization and surgery. FINDINGS: Preoperative embolization occluded an estimated range of 10 to 90% of the nidus. Minor embolization related bleeding without clinical relevance occurred in 5 patients. Significant embolization related bleeding resulting in earlier than planned surgery occurred in another 5 patients. All embolization related haemorrhages occurred within 24 hours. Average total operating time was 343+/-106 min and average blood loss was 684+/-858 ml. Unequivocal bleeding difficulty from the nidus and a total blood loss of more than 1000 ml were encountered in 7 instances and dissection was tedious due to a bleeding AVM core in 5 other cases. A congested AVM core was the source of bleeding in 11 patients and paraventricular neovascularization in one. 6 of the 11 cases with a congested AVM core had suffered minor or substantial haemorrhage after a preoperative endovascular procedure. Intraoperative nidus congestion was noted in this series after an interval as long as 2 weeks after the last embolization. Combined management resulted in permanent morbidity in 6 of the 38 cases. In 4 of them the neurological deficit was associated with an intraoperative bleeding problem, in all due to congested nidus. Morbidity had to be correlated with major haemorrhage resulting from preoperative embolization in 2 instances. CONCLUSIONS: Intranidal embolization prior to surgical removal of AVM can lead to a congested residual nidus and intraoperative bleeding. Minor leakage after preoperative embolization is an inconsistent warning sign of nidus congestion. Nidus outflow after intranidal embolization appears to require a few weeks for normalization. Delay of surgery after embolization should be considered in cases of suspected congested residual nidus. The danger of major haemorrhage or arterial revascularization during this waiting period appears small.

Blood Loss, Surgical↗
PubMed2003

[Features of frontotemporal dementia from the perspective of a special family support group].

Eight spouses of patients diagnosed with frontotemporal dementia (FTD) participated in a special support group. Seven weekly sessions of 90-min duration were held. This pilot project provided the opportunity to learn more about FTD and the specific problems and needs of caregivers. Their problems are predominantly due to changes in the patients' personalities and behaviour, not to the cognitive impairment. Furthermore, in contrast to Alzheimer's disease, patients are relatively young, the current state of scientific knowledge about FTD is unsatisfactory, and the disease is almost unknown among physicians. As part of the group activity, caregivers received information on the typical symptoms of FTD. This enhanced their understanding of the alterations in the patients' personalities and behaviour and facilitated acceptance of the disease. During group meetings, participants were encouraged to express their own needs and to deal with painful emotions including aggression, anger, mourning, and guilt. The caregivers felt relieved by sharing their problems with others. They were able to learn from each other and to exchange suggestions and solutions. The group also helped to establish new contacts and friendships. Participants' evaluations of the novel intervention were very positive. We conclude from these initial observations that support groups are needed for caregivers of patients with FTD which are tailored to their specific needs.

Adaptation, Psychological↗
PubMed2003

[Therapeutic interventional neuroradiology in acute stroke].

Interventional neuroradiological techniques are described, which are used for revascularisation of the intra-extracranial vessels in acute stroke. The results are based on our experience gained during the endovascular treatment of more than 300 patients suffering from acute stroke during the last years. Indication, procedures and results of intraarterial thrombolysis, thrombo-aspiration, percutaneous transluminal angioplasty, and implantation of stents in cases of occlusion or pseudoocclusion of brain supplying vessels are discussed. Furthermore first experiences with new techniques from other centers are presented, e.g., thrombolysis by ultrasound (sonothrombolysis), by angiojet aspiration, and laser evaporation of the thromboembolic occlusion of intra- and extracranial blood vessels.

Acute Disease↗
PubMed2001

Effect of age on outcomes of tertiary rehabilitation for chronic disabling spinal disorders.

STUDY DESIGN: A prospective cohort study evaluating age as a factor in treatment outcomes for chronic disabling work-related spinal disorders undergoing tertiary rehabilitation. OBJECTIVE: To assess the association between age and objective psychosocioeconomic treatment outcomes for work-related spinal disorders undergoing functional restoration. SUMMARY OF BACKGROUND DATA: As early as the 1950s, a link between age and low back symptoms has been identified in the literature. Several studies have demonstrated that the occurrence of low back pain is positively correlated with age up to about 50-60 years, after which prevalence declines. It has been argued that this pattern is stronger for more severe, chronic back pain cases. Little research attention has been given to age as a factor in treatment outcomes for work-related spinal disorders. METHODS: A cohort of 1052 chronically disabled (none working full-time when starting the rehabilitation program) spinal disorder (CDSD) patients were placed into five groups based on age: Group 1, <25 years (22 +/- 2 years, n = 59); Group 2, 25-34 years (30 +/- 3 years, n = 301); Group 3, 35-44 years (39 +/- 3 years, n = 381); Group 4, 45-54 (49 +/- 3 years, n = 237); and Group 5, > or =55 years (59 +/- 4 years, n = 74). All patients completed a functional restoration program combining quantitatively directed exercise progression with a multimodal disability management approach using psychological and case management techniques. Before the start of the program, and again on completion of the program, all patients received a psychosocial evaluation and were also assessed on a variety of physical motion, strength, aerobic, and functional factors, and a cumulative score was calculated, which aggregates and averages these physical measures. A structured clinical interview examining socioeconomic outcomes (work return, health utilization, recurrent injury, and resolution of financial disputes) was conducted at 1 year after program completion, and at least partial information was obtained from this interview on all consecutive patients in the study. RESULTS: The length of pretreatment disability increased with age (P < 0.001), as well as pretreatment surgery rates (P < 0.002). A Mantel-Haenzel chi2 test for linear trend across age groups revealed that the percentage of patients who returned to work declined progressively from 100% in Group 1 to 69% in Group 5 (P < 0.001). The same linear trend was revealed for the percentage of patients retaining work at the end of 1 year (98-62%, P < 0.001). Older workers returned to the same job and/or the same employer (P < 0.005). Younger workers found different jobs with new employers (48-11%, P < 0.0001). Analysis of variance for the disability questionnaire revealed that after treatment subjective disability progressively increased (while improvements decreased) from Group 1 to Group 5 (P < 0.01). The cumulative physical score variable, even normalized for age, was progressively lower from Group 1 to Group 5, both at pretreatment (P < 0.03) and post-treatment (P < 0.02). CONCLUSIONS: The present study represents the first large-scale examination of the association between age and treatment outcomes for a work-related CDSD population. Age is significantly and linearly related to pretreatment duration of disability and frequency of pretreatment surgeries. After rehabilitation treatment there is a linear decrement in both work return and work retention, so that younger patients are far more likely to return and hold work after functional restoration. Older workers who go back to work are much more likely to return to the same employer and do the same job, or to become self-employed. Calculation of odds ratios revealed that patients >55 years are 5.68 times more likely to return to the same job and employer, relative to those <25 years; those >55 years were also approximately three times more likely than those <25 years to return to the same employer, compared with those <25 years. Younger workers are far more likely to take a different job and/or seek a new employer. Older patients are also somewhat more likely to seek a new health provider to deal with perceived residual pain/disability. This trend coincides with their higher post-treatment subjective disability levels, and their lower cumulative physical scores both prerehabilitation and postrehabilitation. However, age does not affect additional surgery rates, subsequent injuries, or delays in settling financial disputes.

Absenteeism↗
PubMed2001

Efficacy of ultrasound B-scan compared with physical examination in follow-up of melanoma patients.

BACKGROUND: The value of ultrasound B-scan for routine follow-up of melanoma patients still is not generally accepted. Therefore, the authors compared the efficacy of physical examination (PE) with ultrasound B-scan (UBS) for detection of regional tumor recurrence in melanoma patients. The aim of the current study was to evaluate whether early detection of metastases improves relapse-free and overall survival. METHODS: For a period of 4 years, 829 consecutive melanoma patients were followed prospectively. Physical examination of 3011 patients and concomitant UBS of in-transit routes and regional lymph node basins were performed. Suspicious lesions were diagnosed by fine-needle aspiration cytology and pathology. RESULTS: During the study period, 242 (90.6%) of 267 patients with melanoma recurrences were first recognized by PE or UBS within the routine follow-up program. The sensitivities of both methods differed significantly (P = 0.001). Metastases were detected by PE in only 61 of 242 recurrences (25.2%, 95% confidence interval [CI]: 19.9-31.2%), whereas UBS revealed 240 recurrences (99.2%, 95% CI: 97.3-99.6%). The specificity was 98.4% (95% CI: 97.8-98.8%) and 98.3% (95% CI: 97.7-98.7%), respectively. Survival of 103 patients who presented with a first nodal melanoma recurrence was followed and analyzed by multiple Cox regression. Overall survival was affected by the diameter of the largest metastasis (P = 0.001) and the number of metastatic lesions (P = 0.012). CONCLUSION: The study found that ultrasound B-scan was highly effective in the early detection of regional melanoma metastases compared with physical examination. Earlier detection of such metastases seemed to result in improved overall survival.

Adolescent↗
PubMed2001

Evidence for a satellite secretory pathway in neuronal dendritic spines.

Long-term information storage within the brain requires the synthesis of new proteins and their use in synapse-specific modifications [1]. Recently, we demonstrated that translation sites for the local synthesis of integral membrane and secretory proteins occur within distal dendritic spines [2]. It remains unresolved, however, whether a complete secretory pathway, including Golgi and trans Golgi network-like membranes, exists near synapses for the local transport and processing of newly synthesized proteins. Here, we report evidence of a satellite secretory pathway in distal dendritic spines and distal dendrites of the mammalian brain. Membranes analogous to early (RER and ERGIC), middle (Golgi cisternae), and late (TGN) secretory pathway compartments are present within dendritic spines and in distal dendrites. Local synthesis, processing, and transport of newly translated integral membrane and secretory proteins may thus provide the molecular basis for synapse-specific modifications during long-term information storage in the brain.

Animals↗
PubMed2000

Ultrasound-guided fine-needle aspiration cytology in the early detection of melanoma metastases.

BACKGROUND: The early detection and treatment of tumor recurrences in melanoma patients is dependent on reliable, sensitive, and specific techniques to verify suspected tumor metastases. As of now, fine-needle aspiration cytology (FNAC) has yet to establish itself in the routine follow-up of melanoma patients. METHODS: FNAC procedures were performed in melanoma patients with palpable tumors or nonpalpable, ultrasonically suspicious lesions. Cytodiagnostic evaluation of fine-needle samples obtained from suspicious lesions was performed morphologically. Findings were validated either by histopathologic diagnosis or prolonged clinical follow-up. RESULTS: The cytologic examination of 739 FNACs from 330 melanoma patients was conducted within 1 day of sampling. Complications were not observed. This study showed a sensitivity of 97.9% and a specificity of 100.0%. Moreover, in 158 FNACs derived from lesions with a diameter less than 1 cm a sensitivity of 94.6% was achieved. Diagnosis of metastatic melanoma with unknown primary tumor was established in 20 cases. CONCLUSIONS: FNAC is very reliable for the early detection of melanoma metastases. FNAC is a swift method free of complications and is able to replace diagnostic surgery completely for nonmalignant lesions in a large number of patients. Moreover, FNAC is especially useful in combination with ultrasound in melanoma follow-up and can enable diagnosis of lesions smaller than 1 cm without impairment of sensitivity or specificity.

Adolescent↗
PubMed2000

Coding and noncoding variation of the human calcium-channel beta4-subunit gene CACNB4 in patients with idiopathic generalized epilepsy and episodic ataxia.

Inactivation of the beta4 subunit of the calcium channel in the mouse neurological mutant lethargic results in a complex neurological disorder that includes absence epilepsy and ataxia. To determine the role of the calcium-channel beta4-subunit gene CACNB4 on chromosome 2q22-23 in related human disorders, we screened for mutations in small pedigrees with familial epilepsy and ataxia. The premature-termination mutation R482X was identified in a patient with juvenile myoclonic epilepsy. The R482X protein lacks the 38 C-terminal amino acids containing part of an interaction domain for the alpha1 subunit. The missense mutation C104F was identified both in a German family with generalized epilepsy and praxis-induced seizures and in a French Canadian family with episodic ataxia. These coding mutations were not detected in 255 unaffected control individuals (510 chromosomes), and they may be considered candidate disease mutations. The results of functional tests of the truncated protein R482X in Xenopus laevis oocytes demonstrated a small decrease in the fast time constant for inactivation of the cotransfected alpha1 subunit. Further studies will be required to evaluate the in vivo consequences of these mutations. We also describe eight noncoding single-nucleotide substitutions, two of which are present at polymorphic frequency, and a previously unrecognized first intron of CACNB4 that interrupts exon 1 at codon 21.

Amino Acid Sequence↗
PubMed2000

Three-dimensional reconstructed rotational digital subtraction angiography in planning treatment of intracranial aneurysms.

We evaluated three-dimensional (3D) reconstructions of 200 degrees rotational digital subtraction angiography (DSA) images for their contributions to improving the safety of endovascular embolization of intracranial aneurysms. Standard DSA and 200 degrees rotational DSA were performed in 40 adult patients (aged 21-77 years) with 45 intracranial aneurysms. Information obtainable from standard DSA and 3D-DSA images about aneurysm shape and size was compared. In 40 (89%) of the 45 aneurysms 3D-DSA gave additional information about the anatomy of the aneurysm. In 17 (43 %) of these cases aneurysm anatomy could be visualized better on 3D-DSA than on standard DSA images. In three cases only 3D-DSA images showed blood vessels originating from the aneurysm. Reconstructed 3D images were also helpful in visualizing partially clipped aneurysms. On maximum-intensity projection images it was even possible to depict previously embolized aneurysms. Blood vessels originating from the aneurysm are visible on 3D-DSA images, and even previously clipped aneurysms can be visualized well. Rotational DSA with 3D reconstruction is a helpful tool in the assessment of intracranial aneurysms.

Adult↗
PubMed2000

[Ultrasound-guided fine needle aspiration cytology (FNAC) of unclear lesions in melanoma patients].

AIM: Fine needle aspiration cytology (FNAC) is widely used in oncology to obtain the diagnosis of unclear tumours in cancer patients. However, because the method is established only in few melanoma centers, we performed this study to evaluate ultrasound guided FNAC in routine follow-up of melanoma patients. METHOD: Unclear tumours recognised during routine follow-up of melanoma patients underwent ultrasound guided fine needle aspiration with cytological examination. The results were then compared to subsequent histopathology or future clinical outcome. RESULTS: 275 unclear tumours received ultrasound guided fine needle aspiration with cytological examination. Sensitivity showed to be 95.6% [95% CI: 91.5-98.1], specificity was 100% [95% CI: 96.2-100.0]. The positive predictive value was 100.0% [95% CI: 97.9-100.0], the negative predictive value 92.2% [95% CI: 85.1%-96.9%]. In 89 cases lesions turned out to be cytologically benign thus diagnosis avoiding surgery. In lesions with diameters up to 10 mm sensitivity and specificity were 91.4% and 100.0%, respectively. CONCLUSION: Ultrasound guided FNAC proved to be a minimal invasive procedure in the diagnosis of unclear tumours in the follow-up of melanoma patients. It allows definite diagnosis and avoids unnecessary diagnostic surgery.

Adolescent↗
PubMed2000

Ignicoccus gen. nov., a novel genus of hyperthermophilic, chemolithoautotrophic Archaea, represented by two new species, Ignicoccus islandicus sp nov and Ignicoccus pacificus sp nov. and Ignicoccus pacificus sp. nov.

Two species of novel, chemolithoautotrophic, sulfidogenic micro-organisms were isolated from submarine hydrothermal systems in the Atlantic (at the Kolbeinsey Ridge north of Iceland) and in the Pacific (at 9 degrees N, 104 degrees W). The coccoid cells grew within a temperature range of 70-98 degrees C (optimum around 90 degrees C). They gained energy by reduction of elemental sulfur using molecular hydrogen as the electron donor. 165 rDNA-based sequence comparisons revealed that the organisms are members of the crenarchaeal branch of the Archaea. They represent a new, deeply branching lineage within the family of the Desulfurococcaceae. In DNA-DNA hybridization experiments both strains exhibited low levels of hybridization to each other and to further representatives of this family. Therefore, they represent a new genus, for which the name Ignicoccus gen. nov. is proposed. At present it consists of two new species, Ignicoccus islandicus sp. nov. (type strain is Kol8T = DSM 13165T = ATCC 700957T) and Ignicoccus pacificus sp. nov. (type strain is LPC33T = DSM 13166T = ATCC 700958T).

Base Composition↗
PubMed2000

Monitoring disease burden and preventive behavior with data linkage: cervical cancer among aboriginal people in Manitoba, Canada.

OBJECTIVES: This study sought to estimate rates of cervical cancer and Papanicolaou testing among Aboriginal and non-Aboriginal women in Manitoba, Canada. METHODS: Data were derived through linking of administrative databases. RESULTS: In comparison with non-Aboriginal women, Aboriginal women had 1.8 and 3.6 times the age-standardized incidence rates of in situ and invasive cervical cancer, respectively. With the exception of those aged 15 to 19 years, Aboriginal women were less likely to have had at least 1 Papanicolaou test in the preceding 3 years. CONCLUSIONS: Data linkage provides a rapid and inexpensive means to estimate disease burden and preventive behavior in the absence of registries. There is an urgent need for an organized Papanicolaou test screening program in the Aboriginal population.

Adolescent↗
PubMed1999

The association of the SF-36 health status survey with 1-year socioeconomic outcomes in a chronically disabled spinal disorder population.

STUDY DESIGN: The Short Form Health Survey (SF-36) was administered to patients with chronic spinal disorders both before and after tertiary rehabilitation. The association of the SF-36 with various socioeconomic outcomes was then examined. OBJECTIVES: To assess the correlation of scores on SF-36 with treatment program completion and clinically meaningful 1-year socioeconomic outcomes. SUMMARY OF BACKGROUND DATA: There has been much interest in identifying variables that can predict which disabled workers with chronic spinal disorders will have good versus poor socioeconomic outcomes after tertiary rehabilitation. Results of previous research have indicated that psychosocial factors are better predictors of such outcomes than physical factors. A more recent trend in research is assessing health-related quality of life from the health care recipient's perspective. METHODS: The SF-36 was administered to a cohort (n = 146) of patients chronically disabled by spinal disorders before entry into a tertiary functional restoration program. Of this cohort, preprogram SF-36 scores and 1-year socioeconomic data were available for 128 program completers and 18 program noncompleters. The pre- and postprogram SF-36 scores of program completers for each of the outcome variables were compared. RESULTS: Better scores on the preprogram SF-36 Social Functioning and Bodily Pain scales were found to be associated with successful completion of the treatment program. Postprogram SF-36 scores were more frequently associated with outcomes than were preprogram scores. Most SF-36 scores, especially the physical domain scales, were associated with the variables of return to work, work retention, and use of health care resources. The overwhelming majority of significant associations were between higher (i.e., better) SF-36 scores and "good" treatment outcomes (e.g., return-to-work). CONCLUSIONS: The large number of associations between SF-36 scores and outcome variables highlights the importance of assessing the health-related quality of life of patients, and supports the use of the SF-36 in accomplishing this task. Among the findings, perhaps the most significant was the value of assessing health-related quality of life, particularly the subjective physical components, after completion of a functional restoration program. Prediction of long-term socioeconomic outcomes is likely to be improved if assessment is conducted at the end of the treatment process. SF-36 is recommended for assessing general health status, and more spine-specific measures are recommended for assessing spinal pain and disability variables.

Adult↗