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Biomedical subjects

P Roth

Publications and source records attributed to P Roth.

At least 19 recordsLinked to original sources
PubMed1992

Tumours of the limbic and paralimbic systems.

Clinical manifestations, findings, management and outcome of a series of 177 cases with tumours of the limbic and paralimbic systems are presented. There was no operative mortality. Postoperatively 95% of them had no or only minor neurological deficits. Most of them were able to resume work. Pre-operatively 77% of the patients had epilepsy, but 84% became seizure-free after tumour removal. All 77 cases with malignant tumours died within 1-5 years. In the past many neurosurgeons were reluctant to attempt complete tumour removal in these areas. This series demonstrates the efficacy of highly skilled microneurosurgery.

Adolescent↗
PubMed1992

Adherence of human newborn infants' monocytes to matrix-bound fibronectin.

The localization of monocytes to sites of inflammation is mediated by interactions with extracellular matrix components including fibronectin, a nonimmune opsonin with binding sites for collagen, fibrin, heparin, and cell surfaces. This study demonstrates that newborn infants' monocytes bind to both gelatin (i.e., denatured collagen) and matrix-bound fibronectin to a degree comparable to that of adult-derived cells.

Adult↗
PubMed1992

Changes of erythropoietic and storage iron components in certain clinical situations as evaluated by ferrokinetic investigations.

A method is described for the quantitative analysis of in vivo organ measurements of 59Fe activity in ferrokinetic investigations. The time-activity curves obtained by sequential surface monitoring over sacrum, liver and spleen can be resolved quantitatively into their different components contributing to the recorded count rate. The analysis is performed in three steps: (1) Count rate contributions from activity in other organs and from scattered radiation from regions outside the organ under investigation are corrected. (2) Distinction is made between radioactivity uptake of the tissue and radioactivity contained in the perfusing blood. (3) The resulting net organ activity is then further resolved into an erythropoietic and a storage iron component by use of a computer program (SAAM-27) and assuming a compartmental model for internal iron exchange. The method was tested in three groups of patients with different haematological disorders and in normal controls. Characteristic patterns of the parameters are found for different diseases and the results correlated well with the clinical findings. It is concluded that in vivo organ measurements of 59Fe activity, when performed and analysed with sufficient care, can provide an insight into the dynamics of the iron exchange that is taking place in an organ. This analytical approach may improve the diagnostic predictions of ferrokinetic investigations.

Erythropoietin↗
PubMed1992

Effect of recombinant human erythropoietin on iron balance in maintenance hemodialysis: theoretical considerations, clinical experience and consequences.

Iron deficiency is the main reason for insufficient response to rEPO therapy. Serum ferritin and transferrin saturation give valuable information on storage iron and iron transport. Iron demand for correction of anemia can easily be estimated after HCT (vol%) x average blood volume (dl) = mg iron. Inadequate iron supply of the bone marrow in the presence of sufficient storage iron in the RES develops frequently under rEPO, possibly explaining the improvement of bone marrow response to rEPO by concomitant intravenous iron supply. The reasons of functional iron deficiency are still speculative.

Anemia↗
PubMed1992

Induction of monocytic cell adherence to matrix-bound fibronectin by phorbol ester.

The inflammatory response requires the localization of monocytic cells to sites of tissue injury through adherence to extracellular matrix molecules such as fibronectin (Fn), a nonimmune opsonin, which binds to collagen, fibrin, heparin and cell surfaces. Adherence to this molecule of two myeloid cell lines differing in their stage of differentiation, was studied. In the baseline state, U937 monocytic cells bound specifically to matrix-bound Fn, while HL-60 promyelocytic cells bound minimally. Exposure to Phorbol myristate acetate (PMA) dramatically increased binding of both U937 and HL-60 cells to Fn with plateau effects at 10 ng/ml for both cell lines and at 30 and 60 minutes for U937 and HL-60, respectively. Treatment with metabolic inhibitors suggests that PMA stimulation depends at least in part on intact energy metabolism, protein synthesis and cytoskeletal components. This system should help elucidate the early molecular and biochemical events involved in monocyte adherence to the extracellular matrix.

Cell Adhesion↗
PubMed1991

Factors affecting the rearrangement efficiency of an Ig test gene.

A rearrangement test gene, pHRD, containing the mouse IgH enhancer and the metallothionein promoter, has previously been shown to rearrange efficiently after transfection into a pre-B cell line. Experiments are now reported that assess the requirements of the DNA substrate as well as of the transfected cells for efficient rearrangement. It was found that deletion of the metallothionein promoter or substitution of the IgH enhancer by the kappa enhancer did not affect rearrangement. However, deletion of the Ig enhancer reduced the efficiency. Transfection of pHRD into stable hybrids of pre-B cells and myeloma cells resulted in a high frequency of rearrangement only if certain myeloma chromosomes were lost. Furthermore, pHRD introduced into rearrangement incompetent myeloma cells upon subsequent cell fusion with pre-B cells was rearranged only very rarely and then apparently only immediately after cell fusion. Stable pre-B cell x myeloma hybrids that retained the critical myeloma chromosomes were found to have lost VDJ recombinase activity and transcripts of the RAG-1, RAG-2 and TdT genes. It is concluded that transcription, i.e., the copying of the DNA by polymerase, is probably not required for rearrangement, but that the rearrangement substrate must be in an "open" chromatin state, such as may be provided by transcriptional factors. Furthermore, the absence of rearrangement in myeloma cells is apparently due to the continued action of an inhibitor of rearrangement.

Animals↗
PubMed1991

Intracranial venous hypertension and the effects of venous outflow obstruction in a rat model of arteriovenous fistula.

A model of rat arteriovenous fistula (AVF) was created using a proximal common carotid artery to distal external jugular vein anastomosis. Anatomical dissections revealed that the external jugular vein is the primary vessel draining intracranial venous blood. Physiological measurements were made with the AVF open and closed, and during venous outflow occlusion of the contralateral external jugular vein. Opening the AVF increased torcular pressure from 6.5 +/- 0.6 to 13.5 +/- 1.1 mm Hg and decreased mean arterial pressure from 82.7 +/- 1.8 to 62.8 +/- 1.8 mm Hg (both P less than .05), decreasing cerebral perfusion pressure from 76.2 +/- 1.7 to 49.3 +/- 2.2 mm Hg (P less than .05). Middle cerebral artery blood flow velocity (MCA BFV) decreased from 6.8 +/- 1.1 to 4.2 +/- 0.7 cm/s (P less than 0.05). In rats with an AVF, occlusion of venous outflow increased torcular pressure to 34.8 +/- 3.1 mm Hg (P less than 0.05), MCA BFV decreased to 1.8 +/- 0.5 cm/s (P less than 0.05), and severe ischemic changes were seen on the electroencephalogram. Under this condition, torcular pressure and systemic arterial pressure had a positive linear relationship (P less than 0.05), whereas in control rats torcular pressure and arterial pressure had no relationship. Restoration of cerebral perfusion pressure by release of venous outflow occlusion and AVF closure transiently increased MCA BFV to 69% above baseline (P less than 0.05). Histological examination 1 week after permanent venous outflow occlusion revealed venous infarction, subarachnoid hemorrhage, and severe brain edema in rats with an AVF but not in control rats without an AVF. This model of cerebrovascular steal with venous hypertension reproduces both hemodynamic and hemorrhagic complications of human AVF and emphasizes the importance of venous outflow obstruction and venous hypertension in the pathophysiology of these lesions.

Animals↗
PubMed1991

Low-dose doxapram for apnea unresponsive to aminophylline in very low birthweight infants.

This study was designed to test whether the addition of low-dose (less than or equal to 1.5 mg/kg/h) doxapram may help wean from positive airway pressure very low birthweight (less than or equal to 1250 g) infants with apnea unresponsive to aminophylline. Doxapram infusion was started at 0.1 to 0.5 mg/kg/h and increased as necessary up to a maximum of 1.5 mg/kg/h. Average birthweight (N = 12) was 1026 +/- 170 g (mean +/- SD, range 740 to 1250), gestational age 27.8 +/- 2.6 weeks (range 24 to 34), postnatal age 24.2 +/- 9.4 days (range 13 to 40), central spun hematocrit 44% +/- 4% (range 38% to 48%), and theophylline level 57.1 +/- 7.7 mumol/L. Doxapram therapy resulted in weaning to a head box in 11 of 12 patients; two required a subsequent course after stopping doxapram. Since the only observed toxicity was mild irritability in one patient, we conclude that very low birthweight infants with apnea unresponsive to aminophylline and older than 1 week of age often respond to the addition of low-dose doxapram with only minimal side effects. Since there was a negative correlation between theophylline level and the effective doxapram dose (r = -.64, N = 13, P less than .05), we recommend that treatment with doxapram be considered in the United States only in those infants with a theophylline level greater than or equal to 88.8 mumol/L, in order to limit the cumulative dose of benzyl alcohol administered.

Aminophylline↗
PubMed1991

[Sagittal palatine rugae--a whim of nature?].

The fact that, for the first time in the Erlangen Orthodontic OPD's inventory of casts, sagittal palatine rugae have been observed in a dental student gave rise to a search of the available publications for a similar finding. As there seems to be no comparable observation in the literature, the case with the palatine rugae arranged in this unique pattern is described.

Humans↗
PubMed1991

[Frequency of tooth agenesis in CLP patients with eruption of all four third molars].

Tooth agenesis was investigated in 101 patients with complete unilateral or bilateral cleft lip and palate presenting four third molars. The prevalence was found to be six times higher than in the control group. The most commonly missing teeth were the upper second premolars and the upper lateral incisors. With the exception of one patient, tooth agenesis in the mandible was only found in combination with congenital absence of teeth in the maxilla.

Anodontia↗
PubMed1991

[Hydrophobicity and microbial production. 1. Selection of oleophilic microorganisms and qualitative characterization by several ecologically and technologically relevant activities].

From samples of different origin microorganisms were selected using the property of oleophily. All oleophilic isolates (30 strains are characterized in more detail) proved to be Gram-positive, nonsporogenic bacteria, obviously belonging to the group of coryneforms. They are growing on a broad spectrum of substrates, 11 strains are facultatively methylotrophic. They are utilizing methanol as well as n-alkanes and glucose without any supplines. 6 strains are able to degrade and decolorize triphenylmethane dyes, for example crystal violet and malachite green. Because of the degradative capacities, combined with the hydrophobic properties of the cell surface, the group of the oleophilic bacteria seems to be very promising in relation to the development of environmental technologies and ecological investigations.

Actinomycetales↗
PubMed1991

[Gorlin-Goltz syndrome].

We present here a case of a patient with Gorlin-Goltz Syndrome treated and followed up for more than 22 years. During the evolution of the disease, we have noted a severe development of symptoms that necessitated the resection of multiple face and trunk basalioms, as well as numerous maxillary keratocysts. One of the cysts has presented the histologic characteristics of an ameloblastic fibroma. Later on, the growth of a squamous cell carcinoma required a partial mandibular resection, primary reconstruction (with AO-plate) and postoperative radiotherapy. Afterwards, a relapse in the symphysar region necessitated, in spite of the presence of lung metastases, another resection of the same region including part of the lower lip with secondary reconstruction by the means of a myocutaneous flap (PMM). A review of the main features of this syndrome has been carried out. With the help of a literature review, all the similar cases already published are here presented and discussed. Furthermore, our therapeutic concept concerning this syndrome is briefly discussed.

Adolescent↗