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Biomedical subjects

M Gross

Publications and source records attributed to M Gross.

At least 199 records · Page 11Linked to original sources
PubMed1998

Rapid DNA extraction method for genetic screening.

A fast, simple, safe and inexpensive method for purification of genomic DNA from blood samples for subsequent PCR is described. All steps are carried out in a single 1.5 ml reaction tube. Neither proteinase K digestion nor precipitation steps are involved. The method is highly efficient. As little as 20 microl of whole blood gives enough DNA for reliable amplification by PCR. The blood cells are lysated in a buffer, the nuclei are pelleted and resuspended in water after a wash step. The resuspension is directly used for PCR.

DNA↗
PubMed1998

Identification of new mutations in the adenylosuccinate lyase gene associated with impaired enzyme activity in lymphocytes and red blood cells.

We determined the DNA sequence of the adenylosuccinate lyase (ASL) gene from a 13 year-old female, who showed a reduced ASL enzymatic activity in lymphocytes and red blood cells and suffered from severe psychomotor retardation. The patient was the offspring of a non-consanguineous marriage. She was found to be compound heterozygous for two missense-mutations located on different alleles (C300-G and G1266-T): the first mutation replaces Pro75 by Ala, the second mutation replaces Asp397 by Tyr.

Adenylosuccinate Lyase↗
PubMed1998

Human brain potentials to violations in morphologically complex Italian words.

Event-related brain potentials were recorded while 12 Italian-speaking subjects read correctly and incorrectly inflected verb forms. Participle forms of three types of verbs were investigated: 1st conjugation verbs (parlato 'spoken'), 3rd conjugation verbs (dormito 'slept'), and irregular 2nd conjugation verbs (preso 'taken'). We compared correct and incorrect participle forms; the latter had stem formation errors and/or incorrect participle endings. Event-related potentials (ERP) showed different responses to incorrect regular and incorrect irregular participle forms: incorrect irregulars (*prendato instead of preso) elicited a widespread negativity, whereas incorrect regulars (*parlito, *dormato) produced no effect. This difference replicates previous results on German inflection and supports the linguistic distinction between lexically-based and rule-based inflection.

Adult↗
PubMed1998

Role of ultrasonography for monitoring tumor necrosis after chemotherapy.

Ultrasonography for monitoring the response of malignant liver lesions to regional therapy offers several advantages. The instrument is easy to transport and can be used in intensive care units, so it is the procedure of choice within the first few days after invasive techniques, such as isolated liver perfusion, to demonstrate tumor response. Changes in size or in the sonomorphological pattern of liver lesions early after therapy indicate a therapeutic response. There are no data available on the sensitivity of ultrasonography for differentiating the necrotic and viable parts of the tumor. If information on the extent of tumor necrosis is crucial for decisions on further treatment of a patient, ultrasonography should be complemented with other techniques, such as fine-needle puncture or imaging techniques such as computed tomography, nuclear magnetic resonance, and single photon emission computed tomography. The contribution of more recent developments in ultrasonography, such as color Doppler analysis of intratumoral blood flow or three-dimensional ultrasonography, for monitoring tumor necrosis remains to be evaluated.

Drug Monitoring↗
PubMed1998

Unexpected candidemia complicating ureteroscopy and urinary stenting.

Two elderly patients with obstructive renal calculi who developed Candida albicans bloodstream infection within 12 h following ureteroscopy and ureteral stenting are described. Both patients were treated with prolonged courses of broad-spectrum antibiotics and were found to have urine cultures positive for Candida albicans prior to the urologic procedures. One patient also developed bilateral candidal endophthalmitis. The clinical presentation was indistinguishable from bacteremia complicating manipulation of the urinary tract. The patients were successfully treated with systemic antifungal therapy. Candiduria may present a risk for dissemination during invasive, relatively simple urologic procedures.

Aged↗
PubMed1998

[Data protection for the national German Central Registry of Pediatric Hearing Disorders].

The German Registry for Hearing Loss in Children (DZH) processes nationwide data from audiological centers. Coping with the accrued data and its subsequent management and analysis requires a high degree of security and control. To establish a nationwide registry it is necessary at an early stage to take into consideration the legal requirements of the participating states. Use of the DZH as an example demonstrates how a pragmatic solution can be reached. Special issues concerning data collection, transfer, storage and deletion, coding strategies to ensure anonymity, checking for duplicate entries, data separation, and automated data analysis and data protection are explained.

Adolescent↗
PubMed1998

[Is diagnosis of persistent pediatric hearing loss still made too late?].

Since 1994, the German Registry for hearing Loss in Children has registered data of 1500 children and by now can present results concerning the age at diagnosis of permanent hearing loss in children in Germany. The mean age at diagnosis is still very high. There is a strong correlation between age at diagnosis and degree of hearing loss, i.e., severe and profound hearing loss, is diagnosed distinctly earlier than mild and moderate hearing loss. On average, mild hearing loss is diagnosed with 6.2 years, moderate h.l. with 4.4 years, severe hearing loss with 2.5 years and profound hearing loss with 1.9 years. This corresponds with the results of regional German studies. At least regionally, in other European countries the age at diagnosis is known to be distinctly lower. In 36% of the children registered in Germany the delay between first suspicion and diagnosis of permanent hearing loss is 1 year or more.

Age Factors↗
PubMed1998

Angiotensin II and coronary artery disease, congestive heart failure, and sudden cardiac death.

An activated renin-angiotensin system is a major risk factor for cardiovascular events. Angiotensin II acts on AT1 and AT2 receptors. Stimulation of AT1 receptors is associated with endothelial dysfunction, mainly as the consequence of an increased vascular production of superoxide radicals, vasoconstriction, platelet activation, enhanced release of plasminogen activator inhibitor-1, activation of immediate early genes c-fos and c-jun, myocyte hypertrophy, connective tissue formation, endothelin-1 synthesis, and activation of growth factors like PDGF and TGF-beta 1. Stimulation of AT2 receptors can mitigate or abolish the growth promoting effects of AT1 receptor stimulation. The contribution of these effects--single or in combination--on the progression of atherosclerotic lesions, the phenomenon of restenosis and the process of remodeling in heart failure is being progressively elucidated. With increasing knowledge about these relationships the inhibition of AT1 receptors appears as a main target in preventive and reparative strategies in cardiovascular diseases.

Angiotensin II↗
PubMed1998

Brain potentials associated with perceptual priming vs explicit remembering during the repetition of visual word-form.

Priming of visual word-form was studied using a reading manipulation in which some words appeared in a backward format (e.g., d-r-o-w) instead of the usual forward format. In Experiment 1, subjects discriminated occasional targets (common first names) from other words with a speeded response. Reaction time was faster for words that had also appeared earlier in the forward format compared to the backward format. Event-related potentials (ERPs) recorded in response to word presentations showed a corresponding difference, a positive offset present during the time interval beginning about 300 ms after word onset from electrodes over occipital and parietal cortex. In Experiment 2, the task was changed to a recognition test, and a later and more widespread ERP response was observed, thus confirming the association between the ERP difference in Experiment 1 and priming rather than explicit remembering. ERP measures were presumably sensitive to neural events underlying the specific influence of recent reading experiences on the processing of visual word-form, thus providing real-time evidence on the neural mechanisms of priming.

Adolescent↗
PubMed1998

Mouse insulin-like growth factor binding protein-6: expression, purification, characterization and histochemical localization.

The mitogenic and metabolic activities of insulin-like growth factors (IGF) are modulated by a family of six high affinity IGF binding proteins (IGFBPs). This study describes the expression of the mouse IGFBP-6 which is unique among IGFBPs in its preferential binding of IGF II, in insect cells using the baculovirus system. The purified, O-glycosylated IGFBP-6 was functional as shown by IGF binding and by inhibition of IGF II-stimulated DNA synthesis in human fibroblasts. Specific antibodies generated in chicken against the recombinant IGFBP-6 were used for Western blotting analysis and immunohistochemistry. Strong immunoreactivity was found in ossifying bones of the cranial base, in cell clusters of the pancreas anlage, in the trigeminal ganglion, on myoblasts, on motoneurons of the spinal cord of embryonic mice. In tissues of adult mouse, strong IGFBP-6 immunostaining was present in epidermal and peridermal layers of the skin, in meningeal layers, in long-striated skeletal muscle, and in the Langerhans' islets of the pancreas. No immunopositive staining was observed in lung and liver indicating that sites of synthesis and IGFBP action are different.

Animals↗
PubMed1998

The incidence of modular tibial polyethylene insert exchange in total knee arthroplasty when polyethylene failure occurs.

One of the primary reasons for utilizing modular tibial polyethylene inserts (MTPI) at the time of total knee arthroplasty is to have the ability to simply exchange the polyethylene at the time of revision surgery when polyethylene failure has occurred. During a 2-year period from January 1993 to December 1994, 62 revision total knee arthroplasties were reviewed from five different institutions in North America, which were performed secondary to modular tibial insert failure. In 55 cases (88.7%), significant scoring and/or damage to the femoral and/or tibial components occurred necessitating revision of one or both components. This series does not support the premise that polyethylene exchange is common at the time of revision surgery for MTPI failure. Of the patients 88.7% had MTPI failure resulted in femoral and/or tibial component revision secondary to surface damage to the femoral component and/or tibial component baseplate. In order to avoid femoral and tibial component wear secondary to MTPI failure, early recognition is necessary to allow the much simpler operation consisting of polyethylene liner exchange only.

Aged↗
PubMed1998

Endolaryngeal contact pressures.

In this work, we present a new method for in vivo endolaryngeal contact pressure measurement with a miniature pressure transducer. Using this methodology, contact pressures can be measured during videoendoscopy at different locations between the artyenoids and also at various locations along the membranous vocal folds. Twenty adults with organic and functional voice disorders and two vocally healthy adults participated as subjects. Endolaryngeal contact pressure measures were made during a series of phonatory tasks varying pitch, loudness, and phonatory onset and offset. Measures were also made during nonphonatory tasks, including throat clearing, coughing, Valsalva maneuvres, and gagging. The most remarkable findings were: (1) interarytenoid contact pressures were considerably greater than intraglottal contact pressures; (2) interarytenoid contact pressures were greater for lower than higher pitches; (3) both interarytenoid and intraglottal contact pressures were remarkably large during hard glottal attack; and (4) overall, the largest endolaryngeal pressures were recorded between the arytenoids, during a thoracic fixation maneuver and during gag reflex.

Adult↗
PubMed1998

The effect of three different recording materials on the reproducibility of condylar guidance registrations in three semi-adjustable articulators.

Sagittal condylar guide settings of three semi-adjustable articulators: WhipMix, Hanau 158 and Denar Mark II were compared using registrations of base plate wax, copper wax and self-curing acrylic resin in two subjects. Four-way ANOVA showed differences between instruments (P < 0.0001), materials (P < 00001), registrations (P < 0.0001), and no difference between operators. Mean differences between materials were 3 degrees and 6 degrees within the range of registration and articulator variability. Denar Mark II gave the highest values, Hanau 158 the lowest with pantronic values generally lower than articulator settings. Neither acrylic nor copper wax were superior to base plate wax. This and previous studies show low reproducibility and variability between instruments, occlusal records and registration material.

Acrylic Resins↗
PubMed1998

A 2-year follow-up of mandibular posture following an increase in occlusal vertical dimension beyond the clinical rest position with fixed restorations.

While resting mandibular posture is continuously changing, repeatable relations of 'physiologic rest position' (PRP) and 'clinical rest position' (CRP) are described in the literature. The PRP is defined as a position of minimal muscle activity and CRP as a more closed clinical reference relation. Relaxed resting posture (RRP) is a repeatable postural range obtained by operator-induced relaxation techniques. This article reports on measurements of mandibular posture in a patient group following an increase in occlusal vertical dimension (OVD) with fixed restorations beyond CRP over 2 years. The relationship of CRP and RRP in the restored and a non-restored control group is compared. The relationship of RRP and corresponding masseteric EMG values to baseline minimal EMG levels is reported for both groups. Resting face height adapted to the increased OVD and remained consistent over 1 and 2 years. The RRP was greater and significantly different from CRP in both groups (P = 0.0001). Results indicated that both CRP and RRP were postural ranges and not specific postural positions. The RRP occurred at minimum baseline EMG levels for both groups and appears to be consistent with physiologic rest position. The possibility of achieving minimal EMG levels at varying interocclusal rest space relations is discussed.

Adaptation, Physiological↗
PubMed1998

Splinting osseointegrated implants and natural teeth in rehabilitation of partially edentulous patients. Part II: principles and applications.

Lone standing splinted implant segments are accepted as optimal. However, in the treatment of partial edentulism, clinical reality often predicates the consideration of splinting teeth and implants due to variables of tooth/implant location and available bone support. This article presents a review on biomechanical aspects of splinting teeth and some considerations of splinting teeth and implants. A proposed classification of splinting applicable to both teeth and implants is presented as well as a discussion of the clinical aspects of splinting illustrated with clinical cases.

Dental Abutments↗