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Biomedical subjects

M Hess

Publications and source records attributed to M Hess.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Psychoacoustic scaling of acoustic voice parameters by multicenter voice ratings].

BACKGROUND: The purpose of the study was to analyze if perceptual voice quality ratings of the well-known RBH rating procedure (a 4-point scale of roughness, breathiness, and hoarseness) covary with acoustical voice parameters. METHODS: 120 voice samples from subjects with healthy and hoarse voices were rated on the RBH-index in a multicenter study with 31 raters. Multivariate regression tree analysis classified the perceptual ratings as "gold standard". Voice samples were acoustically analyzed with a feature extraction method. Feedforward-networks were trained to selected acoustical parameters having highest "relative importance" in the regression trees. Based on the best classifier, a computer program consisting of 50 simultaneous working networks was developed. RESULTS: Mean probabilities for correct classifications were found at 0.65-0.85, implying a significance level over chance (0.25). Classifications of the program matched in 40% with a priori values in the categories roughness combined with breathiness, and in 65% in at least one domain. CONCLUSIONS: The new method described here provides a psychoacoustically based "objective" classification of hoarse voices, which seems to enable future analysis of new parameters (like GNE), which may even improve the present results.

Acoustics↗
PubMed2001

[Use and results of universal newborn hearing screening with ALGO portable device].

BACKGROUND: Congenital hearing disorder, which has an occurrence of 1 in 1000 newborn babies, is a health problem that should be taken seriously. Once it has been discovered too late, it leads to lifelong language, intellectual, emotional and social problems. The aim of this project was the critical evaluation of a universal, ABR-based newborn hearing screening, looking at the specificity and the success of the method used as well as the organisational requirements and costs involved with this method. METHODS: From August 1999 until March 2000, 464 newborn babies, born at the University Hospital Eppendorf in Hamburg, were examined with the Algo portable. Another 31 children, all younger than 6 months, were also examined with the Algo portable, because of suspected hearing loss. When a child got a refer twice by the Algo portable, the child was examined again, using the conventional ERA-machine (Evoselect) to confirm the suspected hearing loss and to assess its grade. RESULTS: 98% of the newborns at our hospital were examined. Up to now, out of 13 conspicuous children, the majority of which belonged to the risk group, 6 have been identified as unambiguously bilateral and 2 as unilateral hard of hearing. After an introductory period of two months, the average costs per examination could be set at 38.65 DM and app. 3200 DM per bilateral hearing loss discovered. CONCLUSION: A Universal Newborn Hearing Screening is necessary and can be executed with calculable effort with concern to personnel, time and finance.

Age Factors↗
PubMed2000

Anatomical origin of dendritic cells determines their life span in peripheral lymph nodes.

Dendritic cells (DCs) exhibit considerable heterogeneity in their anatomical location, surface phenotype, and functional properties. In this study, we demonstrate that peripheral lymph nodes contain at least four major, functionally separable, and independently derived, DC subsets, which can be clearly demarcated by their CD11c, CD40, and CD8 expression pattern. Surprisingly, all DCs derived directly from the bone marrow, the myeloid- and the lymphoid-related subsets, turned over fast with t(1/2) of a couple of days. In contrast, DCs exported from the skin, both dermal and epidermal, accumulated 3- to 4-fold slower, turnover that is dramatically increased by cutaneous inflammation.

Administration, Cutaneous↗
PubMed2000

Mucosa-associated lymphoid tissue lymphoma with initial supradiaphragmatic presentation: natural history and patterns of disease progression.

PURPOSE: Mucosa-associated lymphoid tissue (MALT) lymphoma commonly presents in the gastrointestinal (GI) tract. Supradiaphragmatic MALT lymphoma is less common and its natural history is not well defined. This study was conducted to understand the natural history, to determine the frequency of synchronous disease in the GI tract, and to understand the patterns of disease progression after treatment for supradiaphragmatic MALT lymphoma. PATIENTS AND METHODS: We retrospectively reviewed the medical records of 39 patients who presented with supradiaphragmatic MALT lymphoma between 1991 and 1997. RESULTS: The median age of patients was 58 years (range, 25-90 years) with 16 male and 23 female patients. The most common primary site was salivary gland followed by ocular adnexa, lung, oral cavity, and others. Sixteen patients underwent esophagogastroduodenoscopy and biopsy (EGD + Bx) and 4 were found to have gastric involvement. Ann Arbor stages were the following: IEA, 17; IIEA, 5, IIEB, 1; and IVA, 16. The initial treatments were: involved field radiation therapy (n = 10), chemotherapy (n = 14), combination of radiation therapy and chemotherapy (n = 9), observation after biopsy (n = 4), antibiotics only (n = 1), and patient refusal of further intervention (n = 1). Seven patients received antibiotics as a part of the initial treatment. Every patient except for 1 was alive at a median follow-up of 39.5 months (range, 3-83 months). Thirty-six patients achieved complete response (CR) to the initial treatment. The actuarial 5-year progression-free survival rate was 83%. Progression of the disease occurred in 4 patients, with 2 in the stomach. Salvage attempts were made to 4 and were successful in 3. Of the 2 patients who relapsed in the stomach, 1 had negative EGD + Bx at the time of initial diagnosis. An EGD + Bx was not done in the second patient. CONCLUSION: Supradiaphragmatic MALT lymphoma appears to have a favorable prognosis. However, routine evaluation of the stomach is recommended for patients who present with supradiaphragmatic MALT lymphoma at the time of initial evaluation and at the time of relapse. Patients who failed initial therapy can be successfully salvaged with further treatment.

Adult↗
PubMed2000

The outcome of combined-modality treatments for stage I and II primary large B-cell lymphoma of the mediastinum.

PURPOSE: Primary mediastinal large B-cell lymphoma (PML) has clinicopathologic features distinct from those of other diffuse large-cell lymphomas. However, the optimal treatment for this tumor is evolving, and in particular, the role of radiation therapy remains undefined. We conducted a retrospective review to evaluate the role of radiation therapy in this disease. METHODS AND MATERIALS: The medical records of 40 consecutive patients with Ann Arbor Stage I or II PML treated at our institution from January 1980 to December 1995 were reviewed. There were 18 patients with Stage I disease and 22 patients with Stage II disease; 62.5% were women and 37.5% were men. The median age was 32.4 years (range, 17-74 years). The tumor scores were 0 in 1 patient, I in 5 patients, II in 13 patients, III in 7 patients, IV in 4 patients, and unknown in 10 patients. The International Prognostic Index (IPI) was 0 in 10 patients, I in 26 patients, II in 2 patients, and unknown in 2 patients. All patients were treated with doxorubicin-based chemotherapy, and 35 patients received radiation therapy. For most patients who received radiation therapy, an involved field or a modified-mantle field was used, and a dose of 40 Gy in 20 fractions or 39.6 Gy in 22 fractions was administered. Univariate analysis was performed to identify prognostic factors. RESULTS: The median follow-up in surviving patients was 56 months (range, 19-194 months). The actuarial 5-year relapse-free survival (RFS) rate and overall survival (OS) rate for all patients were 67% and 72%, respectively. Thirty-five patients achieved a complete response; 32 of these patients received radiation therapy. The patterns of failure for the complete responders were as follows: locoregional failure alone for 1 patient (at the margin of the radiation field); distant failure alone for 5 patients; and both locoregional (in-field) and distant failure for 1 patient. There were no failures after 2.5 years. None of the 5 patients who never achieved a complete response had local control, and all died with disease. Only 2 of the 5 completed the planned course of radiation therapy; both had massive mediastinal disease. There was no treatment-related death from the initial chemotherapy or radiation therapy. One patient developed a second malignancy (sarcoma) within the radiation field after 13 years. The tumor score was a significant predictor of RFS (p = 0.016) and OS (p = 0.006), but the IPI did not prove to be a significant predictor. CONCLUSION: We recommend consolidative radiation therapy in view of the excellent local control and the lack of significant toxicity. Modified mantle or involved field appears to be an adequate volume, and 39.6-40 Gy appears to be an adequate dose. The tumor score is a significant prognostic factor.

Adolescent↗
PubMed2000

[Hearing screening of high risk newborn infants].

OBJECTIVE: This prospective study reports on the prevalence of hearing impairment in an at-risk neonatal intensive care unit (NICU) population. DESIGN: From 1990 to 1998, 1062 neonates were screened with the use of transitory evoked otoacoustic emissions (TEOAE) and brainstem evoked response audiometry (BERA). RESULTS: 934 infants passed the primary screen for both ears, 75 for one ear, adding up to 95%. 17 infants (1.6%) were lost to follow-up. In fourteen infants (1.3%), bilateral hearing impairment above 30 dB was confirmed. While all children with hearing impairment belonged to the group of 862 children receiving aminoglycosides, only one of them presented no other risk factors. In twelve of the hearing impaired children other anamnestic factors, i.e. dysmorphism, prenatal rubella or cytomegaly, family history of hearing loss or severe peri- and postnatal complications seem to be more probable causes of the identified hearing loss. In one of these children, delayed onset or progression of hearing loss is suspected. CONCLUSIONS: From our data, aminoglycosides are not an important risk factor for hearing impairment, when serum levels are continuously monitored, as in our cohort. After adjustment for other risk factors, birth weight between 1000 gr and 1500 gr and a gestational age between 29 and 31 weeks were no predictive markers for hearing impairment. It might be speculated that the improved medical treatment in a NICU reduces the probability of hearing impairment for those two groups. Conductive hearing loss as a possible additional cause for hearing impairment was not studied in detail, but the high percentage of malformations detected (four out of fourteen hearing impaired infants) demands further monitoring, close follow-up, adequate treatment and counselling.

Audiometry, Pure-Tone↗
PubMed2000

Anatomic and functional studies of the male and female urethral sphincter.

A total of 28 human specimens (14 male, 14 female) was used to perform macro- and microscopic studies on the morphologic basis of the urethral continence mechanism. Furthermore, functional studies were performed in six sheep, with the aim of looking at the pudendal and autonomic innervation of the urethra and the rhabdosphincter, as well as the changes of autonomic innervation after selective denervation. Transurethral ultrasound was performed in 34 continent patients, in order to visualize the contractions of the rhabdosphincter. The membranous urethra is innervated by branches of the autonomic pelvic plexus. The rhabdosphincter is an omega-shaped loop of striated muscle fibers that is innervated by the pudendal nerves. These results are supported by the results of animal experiments that show that the autonomic nerves predominantly innervate and regulate the upper part of the urethra, whereas stimulation of the pudendal nerves leads to a contraction of the lower part of the sheep urethra. In electron-microscopy, marked degeneration of the smooth muscle cells could be seen in the sheep with bilateral denervation.

Adult↗
PubMed2000

Novel approach to acoustical voice analysis using artificial neural networks.

Perceptual rating scales are widely used for the assessment of voice quality. These ratings may be influenced by the individual experience of the listener. Thus, researchers have turned to acoustical measures which may eventually correlate with voice quality. In this study we tested whether multivariate statistics, combined with artificial neural networks, could identify patterns of acoustic voice parameters corresponding to a widely used perceptual rating scale. In a multicenter study with 31 raters, voice samples of 117 individuals with or without voice disorders were perceptually rated. The RBH index, consisting of a 4-point scale of roughness, breathiness, and hoarseness, was used. Voice samples were then analyzed with an acoustical feature extraction and classified using amultivariate regression tree analysis with the perceptual ratings as a priori information. Artificial neural networks were trained to selected acoustic parameters having high "relative importance" in the regression trees. Mean classification accuracies were around 30% with topographic feature maps (trained with Learning Vector Quantization algorithm) and 65-85% with feedforward networks (trained with RProp algorithm). Based on the best-fitting results with feedforward networks, a classification system (computer program) consisting of 50 simultaneous working networks was developed. Using this program, the classification matched 40% of the a prori values in both R and B domains. In 65% they matched at least in one domain. These accuracies are within the range reported by other authors using artificial neural networks in biology and clinical medicine. Thus, the results encourage further research of feedforward networks for acoustic voice analysis.

Humans↗
PubMed2000

Role of nephrin in cell junction formation in human nephrogenesis.

Nephrin is a cell adhesion protein located at the slit diaphragm area of glomerular podocytes. Mutations in nephrin-coding gene (NPHS1) cause congenital nephrotic syndrome (NPHS1). We studied the developmental expression of nephrin, ZO-1 and P-cadherin in normal fetal kidneys and in NPHS1 kidneys. We used in situ hybridization and immunohistochemistry at light and electron microscopic levels. Nephrin and zonula occludens-1 (ZO-1) were first expressed in late S-shaped bodies. During capillary loop stage, nephrin and ZO-1 localized at the basal margin and in the cell-cell adhesion sites between developing podocytes, especially in junctions with ladder-like structures. In mature glomeruli, nephrin and ZO-1 concentrated at the slit diaphragm area. P-cadherin was first detected in ureteric buds, tubules, and vesicle stage glomeruli. Later, P-cadherin was seen at the basal margin of developing podocytes. Fetal NPHS1 kidneys with Fin-major/Fin-major genotype did not express nephrin, whereas the expression of ZO-1 and P-cadherin was comparable to that of control kidneys. Although early junctional complexes proved structurally normal, junctions with ladder-like structures and slit diaphragms were completely missing. The results indicate that nephrin is dispensable for early development of podocyte junctional complexes. However, nephrin appears to be essential for formation of junctions with ladder-like structures and slit diaphragms.

Cadherins↗
PubMed2000

Follicular large cell lymphoma: long-term follow-up of 62 patients treated between 1973-1981.

PURPOSE: Investigators disagree on whether follicular large cell lymphoma (FLCL) behaves like other follicular lymphomas, with no plateau in the survival curve, or as a more aggressive but potentially curable lymphoma. We reported in 1984 results for 62 FLCL patients treated at our institution; the current report updates those results. PATIENTS AND METHODS: Sixty-two patients referred from 1973-1981, including fifteen (24%) patients with Ann Arbor stage I-II and forty-seven (76%) with stage III-IV FLCL. Seven patients received radiation (XRT) alone, forty patients XRT and chemotherapy, and fifteen patients received chemotherapy alone. RESULTS: The median follow-up was 14.7 years. The median survival was 5.1 years, with 21% alive at 15 years. The failure-free survival (FFS) at 10 years was 31%. Univariate analysis revealed that age, Ann Arbor stage, and the International Index correlated with survival. Performance status, number of platelets, and LDH correlated with failure-free survival. CONCLUSIONS: FLCL responds to doxorubicin-based regimens similarly to diffuse large cell lymphoma. Patients with FLCL have the potential for prolonged failure-free survival. Variables that predict the survival in aggressive lymphomas apply as well in this type of lymphoma.

Adult↗
PubMed2000

Presence of avian pneumovirus type A in continental Europe during the 1980s.

Three isolates of avian pneumovirus (APV) were isolated in Germany during 1987 and 1988 from turkeys with clinical signs of turkey rhinotracheitis and one was isolated during 1990 from a broiler breeder flock with typical signs of swollen head syndrome. The isolates were typed using type-specific reverse transcriptase-polymerase chain reactions. The three isolates from turkeys were identified as type A, while the isolate from the broiler breeders was type B. During the late 1980s no APV live-virus vaccine was used in poultry flocks in Germany, which is indicative of the presence of both types at that time. Previous isolates detected from elsewhere in Europe during the 1980s had been only of type B.

Animals↗
PubMed2000

Influence of autothreshold sensing and sinus rate on mode switching algorithm behavior.

Mode switching is beneficial to pacemaker patients with paroxysmal atrial tachyarrhythmias. However, the optimal mode switching algorithm is still in evolution. Mode switching algorithms and atrial sensing circuitry can influence mode switching behavior. This study compared the mode switching behavior of four Medtronic, Inc. implantable devices: Thera DR model 7960 pacemaker, Kappa 700 model KDR701 pacemaker, Gem DR model 7271 dual chamber pacing defibrillator, and Jewel AF model 7250 dual chamber pacemaker atrial and ventricular defibrillator. The Thera and Gem DR use the same mean atrial rate mode switch algorithm. The Kappa and Jewel AF use four of seven short atrial intervals and an atrial fibrillation evidence counter algorithm, respectively. The Thera and Kappa devices use fixed gain sensing and the Gem DR and Jewel AF use autothreshold atrial sensing. Digitally recorded atrial electrograms from 52 episodes of human atrial fibrillation were fed into each device with differing simulated sinus rates before and after the atrial fibrillation. The percent of appropriate mode switching was highest for the Kappa 700 (94%) and lowest for the Thera (85%) (P = 0.046). The time to mode switching was significantly longer for the Thera and Gem DR compared to the Kappa 700 or Jewel AF (all P < 0.05). The time to mode switching was shorter for the Gem DR (9.0 +/- 1.6 s) using autothreshold atrial sensing than for the fixed gain Thera (11.1 +/- 2.1 s, P < 0.05). The mean atrial electrogram amplitude and cycle length were not correlated with the time to mode switching for any device. Faster sinus rates shortened the time to mode switching and prolonged the time to resynchronization in the two devices using the mean atrial interval algorithm. In conclusion, (1) mode switching function among these devices is influenced by algorithms and sensing circuitry, (2) the time to mode switching among these devices is influenced by the algorithm and use of autothreshold atrial sensing, and (3) the sinus rate before and after episodes of atrial fibrillation greatly influences the times to mode switching and resynchronization in devices using the mean atrial interval algorithm.

Algorithms↗
PubMed2000

[Epizootiology of fowls adenoviruses].

Fowl adenoviruses of the serotype 4 from Germany were characterised by restriction enzyme analysis in comparison to isolates from Asia, South America and the FAV4 reference strain KR5. Only strain Da60 which was isolated from a psittacine aviary was identical with the reference strain KR5. None of the isolates was identical with the highly pathogenic strains from India and Ecuador. One-day-old chicks were infected orally and intramuscularly with the reference strain KR5, the psittacine isolate Da60 and isolate K1013 from Ecuador. Whereas no mortality was seen with the two strains KR5 and Da60, the mortality with K1013 was 100%. The main pathological signs were a swollen liver with necrosis and a lymphocyte depletion with a loss of the follicle structure. To investigate a second subject of avian adenovirus epizootiology several FAVs were characterized serologically and with PCR which was combined with the digestion of the PCR products. Including the reference strains, both methods were compared. It was shown that the digestion of the PCR products allows a clear attribution to a specific serotype, which underlines the usefulness of this method for diagnostic purposes.

Adenoviridae Infections↗
PubMed1999

Follicular large cell lymphoma: an aggressive lymphoma that often presents with favorable prognostic features.

It is debated whether follicular large cell lymphoma (FLCL) has a clinical behavior that is distinct from indolent follicular lymphomas, and whether there is a subset of patients who can be potentially cured. We report here our experience with 100 FLCL patients treated at our institution since 1984 with three successive programs. We evaluated the predictive value of pretreatment clinical features, including two risk models, the Tumor Score System and the International Prognostic Index (IPI). With a median follow-up of 67 months, the 5-year survival is 72% and the failure-free survival (FFS) is 67%, with a possible plateau in the FFS curve, particularly for patients with stage I-III disease. Features associated with shorter survival included age >/=60, elevated lactic dehydrogenase (LDH) or beta-2-microglobulin (beta2M), advanced stage, and bone marrow involvement. Stage III patients had significantly better survival than stage IV patients (P <.05). By the IPI and Tumor Score System, 80% of the patients were in the lower risk groups; both systems stratified patients into prognostic groups. Patients with FLCL have clinical features and response to treatment similar to that reported for diffuse large cell lymphoma. Prognostic risk systems for aggressive lymphomas are useful for FLCL. A meaningful fraction of patients may possibly be cured when treated as aggressive lymphomas.

Adult↗
PubMed1999

[Manifestation of epidermolysis bullosa acquisita (EBA) in the ENT area].

Epidermolysis bullosa acquisita (EBA) is a rare, chronic, acquired bullous autoimmune dermatosis. It is characterized by the formation of IgG autoantibodies against type VII procollagen of anchoring fibrils with subepidermal formation of bullous lesions and consequent scarring. The epidemiology of this disease and its characteristic clinical findings cannot be completely surveyed at present due to the limited number of available publications. In general, bullous lesions form on the entire integument and can also involve mucosa. The development of scar-related adhesions on the mucosa of the upper airways and esophagus can lead to serious complications that are difficult to treat. We report our experience in managing a 44-year-old male patient in whom the diagnosis of EBA was established in 1993 on the basis of multiple persistent bullous lesions involving the eye, nose, skin and oral, pharyngeal and laryngeal mucosa. After failing previous medical and surgical therapies, interdisciplinary management resulted in the control of active lesions with extracorporal phototherapy and cyclosporin A.

Adult↗
PubMed1999

The new Palliative Care Outreach Program--a resounding success.

The Palliative Care Outreach Program provides consultation, medical care, and psychosocial, emotional and spiritual support to palliative care patients and their families in an out-patient setting. In just over 1 year of operation, the program has proved to be an essential community-based service.

Community-Institutional Relations↗
PubMed1999

Dynamic exercise normalizes resting blood pressure in mildly hypertensive premenopausal women.

BACKGROUND: Dynamic exercise acutely and transiently lowers resting blood pressure in hypertensive men and is termed postexercise hypotension (PEH). We examined 18 premenopausal women (7 hypertensive and 11 normotensive) to determine if PEH occurs in women and to elucidate possible hemodynamic and hormonal mechanisms. METHODS AND RESULTS: Patients wore an ambulatory blood pressure monitor throughout the day after 40 minutes of a rest sham session and 40 minutes of cycle exercise, of which 30 minutes was performed at 60% of maximal oxygen consumption. Cardiac output and total systemic vascular resistance were determined by Doppler echocardiography before and 15 minutes after sham and exercise. Catecholamines, plasma renin activity, and beta-endorphin were measured over this same period. PEH occurred only in the hypertensive women. Systolic, diastolic, and mean arterial blood pressure decreased in the hypertensive women by a mean of 9.5 +/- 2. 8 mm Hg (P <.01), 6.7 +/- 2.4 mm Hg (P <.05), and 7.7 +/- 2.4 mm Hg (P <.05), respectively, for up to 7 hours after versus before exercise, whereas blood pressure was similar in the normotensive women (P >.05). After exercise, total systemic vascular resistance was lower (P <.01), and cardiac output, catecholamines, and plasma renin activity were greater (P <.01) than before exercise in both groups of women. CONCLUSIONS: PEH was observed for up to 7 hours after exercise in mildly hypertensive women and was not explained by the hemodynamic and hormonal adjustments that occurred after exercise. The magnitude and duration of PEH may be sufficient to normalize the blood pressure of certain hypertensive women throughout most of the day.

Adult↗