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Biomedical subjects

D Schmidt

Publications and source records attributed to D Schmidt.

At least 235 records · Page 13Linked to original sources
PubMed1996

[Incidence, localization, length and course of the cilioretinal artery.Is there an effect on the course of temporal rental arteries?].

BACKGROUND: A cilioretinal artery (crA) can be of clinical importance because of its possible blood supply to central retinal areas. METHOD: 140 undergraduates were investigated ophthalmoscopically. The crA were classified according to length and possible supply to the macular area. In addition, the retinal areas, restricted by the big temporal vessels, were measured. RESULTS: At least one crA was found ophthalmoscopically in 54 out of 140 (38.6%) undergraduates or in 65 (23.2%) of 280 eyes, respectively. 88.7% of the crA were found on the temporal side of the retina. A possible participation in the arterial supply to the macular area was found in 49.1% of the temporal crA. Particularly long crA were seen in 5% of all persons investigated or in 3.2% of all eyes examined, respectively. No significant difference in spherical equivalent appeared between those eyes having a crA and the other eye without one. Calculation of retinal areas revealed that the superior retinal artery showed a continued peripheral course upon the retina if a long crA was present compared to those fundi without a crA. CONCLUSIONS: Every fifth eye and approximately every third person had a least one crA. Long crA were distinctly involved in the blood supply to the macular area or to the central part of the retina. It seems that the retinal temporal arteries are pushed to the superior retinal periphery if a long crA is present, influencing the developmental course of the retinal vessels.

Adult↗
PubMed1996

Syncopes and seizures.

A recent videometric analysis of 56 brief syncopes showed myoclonic activity in 90%, together with head turns, upward gaze, oral automatisms, righting movements and visual and auditory hallucinations in 60-80%. Characteristic precipitation factors, premonition features such as nausea, sweating and palpitation, brief duration (< 25 sec), absence of paroxysmal electroencephalogram activity and no evidence for disorientation, exhaustion or sleep after the attack, are useful discriminating factors.

Eye Movements↗
PubMed1996

Double-blind, placebo-controlled trial of topiramate as add-on therapy in patients with refractory partial seizures.

In a double-blind, randomized, parallel-group trial, we compared topiramate (TPM) with placebo as add-on therapy in patients with refractory partial epilepsy. TPM was titrated either to the target dosage of 800 mg/ day [400 mg twice daily (b.i.d)] or to the maximal tolerated dose if lower. Twenty-eight (28) patients were randomized to each treatment group. In the intent-to-treat analysis, the net median percent reduction relative to placebo in average monthly seizure rate was 54% for patients in the TPM group (p < 0.001). None of the placebo-treated patients and 43% of the patients treated with TPM experienced > or = 50% reduction in seizures (p = 0.001), and 36% of patients assigned to TPM had a 75-100% reduction in seizures (p < 0.01). Secondarily generalized seizures were also significantly reduced in the TPM group (p = 0.044). The most common adverse events (AE) reported in the TPM group were fatigue, impaired concentration, weight loss, dizziness, and paresthesias. AE occurring either during the rapid titration of TPM or at high dosages led 21% of TPM-treated patients to withdraw from the study. Half of these occurred during the titration study period. No serious AE or clinically important changes in clinical laboratory measures were observed. The present study further establishes the favorable profile and good benefit/risk ratio of TPM in resistant partial epilepsy.

Adolescent↗
PubMed1996

A practical guide to when (and how) to withdraw antiepileptic drugs in seizure-free patients.

Most patients with epilepsy will become seizure-free on antiepileptic drugs (AEDs) within a few years of diagnosis. More than 60% will remain so when the medication is withdrawn. After assessing the risks and benefits for the individual patient, withdrawal may be considered by the physician and informed patient or parent if the patient meets the following profile: normal neurological examination, normal IQ, normal electroencephalogram (EEG) prior to withdrawal, seizure-free for 2 to 5 years or longer, and no juvenile myoclonic epilepsy. AEDs can be safely withdrawn in the seizure-free patients over the course of 6 months, possibly even faster, especially in children.

Anticonvulsants↗
PubMed1996

The central sulcal vein: a landmark for identification of the central sulcus using functional magnetic resonance imaging.

The authors evaluated the anatomical location of the central sulcus (CS) in 24 cerebral hemispheres (eight in which tumors were located centrally, 16 in controls) using: 1) classic anatomical landmarks seen on magnetic resonance (MR) imaging (24 hemispheres); 2) functional MR imaging (24 hemispheres); and 3) intraoperative electrical stimulation mapping (eight hemispheres). On MR imaging the CS was identified with certainty in 79% of hemispheres (four of eight in patients, 15 of 16 in controls). Functional MR imaging identified a parenchymal "motor hand area" in only 83% (20 of 24 hemispheres; five of eight in patients, 15 of 16 in controls); this area was located in the precentral gyrus in 16 (80%) of 20, additionally in the postcentral gyrus in 10 (50%) of 20, and exclusively in the postcentral gyrus in four (20%) of 20. In contrast, functional MR imaging detected one to three sulcal veins presumably draining blood from the adjacent motor hand area in 100% (24 of 24) of the hemispheres studied, and anatomical MR imaging and intraoperative mapping localized these veins in the CS. It is concluded that sulcal veins lying deep within the CS: 1) drain activated blood from the adjacent pre- or postcentral cortex during performance of a motor hand task; 2) can be identified easily with functional MR imaging; and 3) are an anatomical landmark for noninvasive identification of the CS and thus the sensorimotor strip. The detection of these veins provides a more consistent landmark than the detection of parenchymal motor areas by functional MR imaging; this technique may be used when classic anatomical landmarks fail to identify the sensorimotor strip.

Adult↗
PubMed1996

[Morphologic endometrium changes with tamoxifen].

Women receiving tamoxifen as adjuvant therapy for breast cancer usually develop atrophy of the endometrium. Cystic polyps as well as endocervical and clear-cell metaplasias also frequently arise in the these atrophic endometria. The invasive endometrial carcinomas we have observed in these women have all been until now either mucinous, clear-cell or serous-papillary carcinomas, that is, different from the endometrioid type of adenocarcinomas that arise under estrogenic stimulation. Our histological studies support the assumption that tamoxifen has an antiestrogenic, gestagen-like action on the endometrium; they contradict the premise that tamoxifen therapy exerts an estrogen effect.

Antineoplastic Agents, Hormonal↗
PubMed1996

[Comparative study of 2-piece colostomy systems (ConvaTec Combihesive Flexible, Coloplast 2002 and Hollister Guardian in the Czech Republic)].

In three surgical centres in the Czech Republik three modern two-piece colostomic systems where compared which are at present available in the Czech republik, incl. an attempt to assess how they influence the quality of life of the patients. The investigation comprised 117 patients mean age 59 years-93 after colostomy, 13 with ileostomy. The investigated systems were ConvaTec Combihesive Flexible, Coloplast 2002, Hollister Guardian two-piece ostomy systems with a closed sac and inner filter. The main investigated parameters were: tolerance of the products, preference expressed by the patient, the state of the skin beneath the plaster and the index of general health (GWBI). From the investigation ensued that in the Czech Republic the system ConvaTec Combihesive proved very useful and there probably will not be a demand for a change to another system offered by distinguished producers, as such a change would not entail any advantages. It was revealed that when the ConvaTec Combihesive system is used, the skin is maintained in a good condition which has a favourable impact on the feeling of wellbeing and improves the quality of life.

Colostomy↗
PubMed1996

The repertoire of CD4+ CD28- T cells in rheumatoid arthritis.

BACKGROUND: While oligoclonality of circulating CD4- CD8 and of CD8+ T cells is not uncommon, clonal dominance within the CD4 compartment is not frequently found in healthy individuals. In contrast, the majority of patients with rheumatoid arthritis (RA) have clonally expanded CD4+ T cell populations. Previous studies have demonstrated that these clonogenic CD4+ T cells do not express the CD28 molecule. To examine the correlation between CD28 expression and clonal proliferation, we have analyzed the T cell receptor (TCR) diversity of CD4+ CD28- T cells in normal individuals and in RA patients. MATERIAL AND METHODS: The size of the peripheral blood CD4+ CD28- compartment was determined in 30 healthy individuals and 30 RA patients by two-color FACS analysis. In 10 RA patients and five controls with more than 2.5% CD4+ CD28- T cells, TCR BV gene segment usage was analyzed with 19 BV-specific antibodies. Oligoclonality was assessed in sorted CD4+ CD28+ and CD28- T cells using TCR BV-BC-specific polymerase chain reaction and size fractionation. Clonal dominance was confirmed by direct sequencing. RESULTS: The CD4+ CD28- T cell compartment was expanded to more than 2.5% in 70% of the RA patients and 30% of the normal individuals. Compared with the CD4+ CD28+ T cells, the TCR BV gene segment usage among CD4+ CD28- cells was grossly skewed with the dominance of single BV elements. Molecular TCR analysis provided evidence for oligoclonality in 17 of 21 expanded BV elements. In two unrelated RA patients who shared both HLA-DRB1 alleles, the TCR beta-chain sequences of dominant clonotypes were highly conserved. CONCLUSIONS: Oligoclonality is a characteristic feature of CD4+ CD28- T cells which are expanded in some healthy individuals and in the majority of RA patients. The lack of CD28 expression is a common denominator of CD4+, CD8+, and CD4- CD8- T cells prone to develop clonal dominance. The limited TCR diversity of clonal CD4+ CD28- populations in RA patients suggests that these T cells recognize a limited spectrum of antigens. The fact that the majority of individuals with marked expansions and oligoclonality of CD4+ CD28- T cells are RA patients suggests a role for these unusual lymphocytes in the pathogenetic events leading to RA.

Amino Acid Sequence↗
PubMed1996

The Missouri planning grant for the education and training of health sciences librarians.

The planning grant at the School of Library and Informational Science (SLIS) at the University of Missouri has two aims: (a) developing a model curriculum for health sciences librarianship at the master's level and (b) developing materials that can be delivered by alternative instructional methods. To accomplish the first aim, the faculty will investigate the possibility of offering courses in other disciplines, such as health care administration, educational technology, adult education, and medical sociology. In addition, the SLIS faculty will investigate the development of new kinds of placement for the students' practicum experience. To reach the second aim, the SLIS faculty will investigate alternative means of delivering both graduate and continuing education. Three instructional modalities will be evaluated. Some material will be delivered via satellite broadcast, some material will be made available via the World Wide Web and some will be presented in an intensive seminar. The outcome of the planning grant will be two distinct plans. The first will be a plan for the curriculum in health sciences librarianship at the master's level. The second will be a plan for offering instruction through alternative methods, both for graduate education and for continuing education.

Computer Communication Networks↗
PubMed1996

Modern management of epilepsy: Rational polytherapy.

Although monotherapy is universally accepted for treating early epilepsy, as many as 40% of patients will continue to have seizures and develop intolerable adverse effects or most commonly, both. Once initial monotherapy has failed, the physician has the choice of either polytherapy by adding a second drug or of alternative monotherapy, that is, substitution of the first drug by another agent active for the same type(s) of seizures. No large randomized comparative trials exist although smaller studies indicate that polytherapy and alternative monotherapy may both achieve complete seizure control in up to 17% and further improvement in approximately 40% of cases. Polytherapy has the advantage of providing benefit in the small minority (15%) of patients who probably cannot be treated satisfactorily by alternative monotherapy, this often being achieved at the price of additional toxicity, undesirable drug interactions and the failure to identify the action of the individual drug. The real basis for rational choice of drugs in polytherapy are features such as efficacy, lack of interaction and low intrinsic toxicity. Theoretical and experimental considerations are of limited value until we know more about the basic mechanism(s) of specific seizures and epilepsy syndromes. At present, it is recommended that undue toxicity and inconvenient drug interactions should be avoided by lowering the dosage of the first drug as much as possible before a second drug is added. In most patients alternative monotherapy, that is, complete removal of the first drug, is a safe and effective option and polytherapy remains available when alternative monotherapy fails.

Anticonvulsants↗
PubMed1996

[Tachyphylaxis of airway response to inhaled bradykinin over several days].

Tachyphylaxis of airway responses has been described for a variety of pharmacological stimuli. A decrease in airway responsiveness to inhaled bradykinin has been reported when challenges were repeated within intervals of 60 minutes. Especially within the framework of drug studies, it is important to know whether tachyphylaxis persist over days. The aim of our study was to assess the occurrence of tachyphylaxis to inhaled bradykinin within several days. Thirteen patients with mild extrinsic bronchial asthma were included into the study. We performed two bradykinin inhalation challenges separated by an interval of three days and determined the provocative concentrations of bradykinin (PC20FEV1) which produced a 20% fall in FEV1. Geometric mean of PC20FEV1 was 0.033 mg/mL in the first and 0.105 mg/mL in the second challenge. These values were significantly different (p < 0.05). Our data demonstrate that tachyphylaxis of the airway response to bradykinin persists over a time period of three days.

Aerosols↗
PubMed1995

Classification of rhabdomyosarcomas and related sarcomas. Pathologic aspects and proposal for a new classification--an Intergroup Rhabdomyosarcoma Study.

BACKGROUND: There is a need to develop a single prognostically significant classification of rhabdomyosarcomas (RMS) and other related tumors of children, adolescents, and young adults which would be a current guide for their diagnosis, allow valid comparison of outcomes between protocols carried out anywhere in the world, and should enhance recognition of prognostic subsets. METHOD: Sixteen pathologists from eight pathology groups, representing six countries and several cooperative groups, classified by four histopathologic classification schemes 800 representative tumors of the 999 eligible cases treated on Intergroup Rhabdomyosarcoma Study II. Each tumor was classified according to each of the four systems by each of the pathologists. In addition, two independent subsamples of 200 of the 800 patients were reviewed according to the new system, so that 343 distinct patients were reviewed once, and 57 of these twice. RESULTS: A study of the survival rates of all subtypes in the sample of 800 patients led to the formation of a new system. This was tested on two independent subsets of 200 of the original cases and found to be reproducible and predictive of outcome by univariate analysis. A multivariate analysis of the 343 patients classified according to the new system indicated that a survival model including pathologic classification and known prognostic factors of primary site, clinical group, and tumor size was significantly better at predicting survival than a model with only the known prognostic factors. CONCLUSION: This new classification, termed International Classification of Rhabdomyosarcoma (ICR) by the authors, was reproducible and predictive of outcome among patients with differing histologies treated uniformly on the Intergroup Rhabdomyosarcoma II protocols. We believe it should be utilized by all pathologists and cooperative groups to classify rhabdomyosarcomas in order to provide comparability among and within multi-institutional studies.

Adolescent↗
PubMed1995

Remodelling of lipoproteins in transgenic mice expressing human cholesteryl ester transfer protein.

Cholesteryl ester transfer protein (CETP) facilitates the transfer of reciprocal exchange of neutral lipids between lipoproteins. To better understand the function of CETP and its role in atherogenic pathways, transgenic mice which express human CETP were generated. The transgene encoding human CETP was under the control of the mouse alpha-fetoprotein enhancer and mouse albumin gene promoter and was expressed exclusively in the liver. The level of human CETP activity in transgenic mouse plasmas was found to be 1- to 5-fold greater than in normolipidemic human plasma. Human CETP induced an approx. 30 and 40% reduction of HDL cholesterol levels in plasma from female and male transgenic mice, respectively, when compared to controls. In addition, multiple alterations in mouse lipoprotein composition were observed in the transgenic mice. Diminished HDL cholesterol levels and disappearance of the apo E-rich HDL1 moiety account for the dramatic reduction in plasma cholesterol. The decrease in HDL cholesterol was accompanied by a marked reduction in HDL particle size and apo A-I content. The cholesterol content and the size of LDL particles increased, but only modestly, in transgenic mouse plasma. In conclusion, human CETP induces a significant remodelling of mouse lipoproteins which results in dramatic reduction in plasma cholesterol levels.

Animals↗