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Biomedical subjects

M Spiegel

Publications and source records attributed to M Spiegel.

At least 19 recordsLinked to original sources
PubMed1994

[Extensive aneurysm of the internal carotid artery with free floating round thrombus].

A large asymptomatic aneurysm of the internal carotid artery containing a free floating thrombus was detected in a 90-year-old woman. The alteration was documented by duplex sonography of the extracranial carotid arteries. At a second examination 4 days later the thrombus was observed to be fixed to the dorsal and distal aneurysm wall. With regard to the age and reduced general state of health of the patient, invasive diagnostic examinations and reconstructive surgery were not indicated and the patient was released in a good condition.

Aged↗
PubMed1993

Lymphatic capillary pressure in patients with primary lymphedema.

Flow and pressure dynamics in minute human lymphatics are unexplored. Lymphatic capillary pressure was measured by the servo-nulling technique at the foot dorsum of 14 patients with primary lymphedema and 15 healthy controls. Glass micropipettes (7-9 microns) were inserted under microscopic control into lymphatic microvessels previously stained by fluorescence microlymphography (FITC-Dextran 150,000). Mean lymphatic capillary pressure was 7.9 +/- 3.4 mm Hg in the controls and 15.0 +/- 5.1 mm Hg in the patients. The difference was significant at the P < 0.001 level. In about half of the patients and control subjects studied pressure fluctuated by more than 3 mm Hg. The mean intralymphatic pressure of lymphedema patients was slightly below mean interstitial pressure measured by J. T. Christensen, N. J. Shaw, M. M. Hamas and H. K. Al Hassan (1985, Microcirc., Endothelium, Lymphatics 2, 267-384) (17.9 mm Hg) in lower leg lymphedema. Microlymphatic hypertension present in patients with primary lymphedema is probably an important factor for edema formation.

Adolescent↗
PubMed1992

Cryptococcal meningitis in systemic lupus erythematosus.

Two cases of cryptococcal meningitis occurring in patients with systemic lupus erythematosus (SLE) are presented, and 24 additional cases from the literature are reviewed. The insidious onset of this infrequent complication is emphasized. The nonspecific neurological findings associated with this infection are often mistakenly diagnosed as a central nervous system manifestation of SLE. Earlier diagnosis and effective antifungal therapy have improved the prognosis of cryptococcal meningitis in SLE patients in recent years. Strategies for the treatment of patients with this complication are discussed.

Adult↗
PubMed1992

Pressure of lymphatic capillaries in human skin.

The network of lymphatic capillaries of the human skin was depicted at the distal part of the tibial plateau by fluorescence microlymphography (fluorescein isothiocyanate-dextran 150,000). Intralymphatic pressure was determined in 28 lymphatic capillaries of 21 healthy volunteers (mean diameter 56.0 +/- 10.0 microns) by a servo-nulling pressure system. It averaged 4.0 +/- 4.5 mmHg (range: -6.8 to +10.7 mmHg). These are the first measurements of pressure in the initial lymphatics of human skin and form a basis with which to compare measurements made in patients with different forms of edema.

Adult↗
PubMed1989

Extracellular matrix of sea urchin and other marine invertebrate embryos.

The extracellular matrix surrounding the sea urchin embryo (outer ECM) contains fibers and granules of various sizes which are organized in recognizable patterns as shown by ultrastructural studies, particularly stereoimaging techniques. The use of the ruthenium red method for retaining and staining the ECM, with modifications of the Luft (Anatomical Record 171:347-368, 1971) method for invertebrate embryos, allows for the clarification of certain structures, particularly fiber compaction in the interzonal region, and microvillus-associated bodies. The inner ECM in the sea urchin embryo includes the basal lamina and blastocoel matrix. Stereoimages show that the fibers which are loosely distributed in the blastocoel matrix become compacted around the periphery of the blastocoel to form the basal lamina. The ruthenium red method was also used on a number of marine invertebrate embryos and larvae, representing different phyla, to facilitate comparisons between their surface coats. The similarities observed in the specimens shown suggest that ECMs are widely found on marine invertebrate eggs, embryos, and larvae, and that they resemble vertebrate ECMs and may, therefore, have similar functions.

Animals↗
PubMed1989

MRI study of Baló's concentric sclerosis before and after immunosuppressive therapy.

An intra vitam diagnosis of Baló's concentric sclerosis in a 39-year-old male is described. To our knowledge this is the first reported case of ante-mortem diagnosis based solely on magnetic resonance imaging (MRI) findings. MRI showed features unique to this process. After high-dose intravenous therapy with prednisone, the clinical symptoms improved, and MRI showed marked changes of the concentric lesions.

Adult↗
PubMed1988

Speech masking. II: Simultaneous masking thresholds under "naturalistic" listening conditions.

This article investigates the role of listening conditions in determining thresholds for probe tones masked by natural speech. These thresholds are of interest because they are a sensitive probe of the activity profile, or spectrum, of sounds such as speech in the auditory system. Most human performance tests are carried out under highly artificial listening conditions, which may not reflect how people listen to speech in common listening environments. In this study, reference conditions (similar to minimal uncertainty listening conditions used in many performance tests) were compared to a "naturalistic" listening condition and to another, intermediate, condition. In the naturalistic listening condition, listeners did not know the frequency or the position of probe tones; additionally, they were required to attend to the semantic content of sentences. In the reference condition, listeners knew the frequency and position of probe tones masked by single syllables. Average thresholds were elevated by 4 dB in the naturalistic listening condition with respect to the reference condition, and thresholds tended to be elevated more for higher-frequency probe tones. The results provide previously unknown information about the resolution of speech sounds in the auditory system during speech comprehension.

Adolescent↗
PubMed1985

The biochemical identification of fibronectin in the sea urchin embryo.

We report the biochemical identification of fibronectin in the basal lamina of the sea urchin embryo. A. punctulata gastrula stage embryos were solubilized in Triton X-100 and the insoluble basal laminae extracted by incubation in buffer containing 8M urea, 2% 2-mercaptoethanol and 2% SDS. Extracted proteins were separated by SDS-PAGE, electrophoretically transferred to nitrocellulose filters and probed with monospecific antibodies directed against human plasma fibronectin (pFN). Incubation in 125I-labelled secondary antibody revealed a single band which co-migrates with human pFN at an apparent molecular weight of 220,000. This is the first direct biochemical demonstration of a fibronectin-like molecule in the sea urchin embryo which cross reacts with antibodies to vertebrate fibronectin.

Animals↗
PubMed1985

Micromere-specific cell surface proteins of 16-cell stage sea urchin embryos.

Evidence is presented of cell-type specificity of surface proteins from the 16-cell stage sea urchin embryo. The protein composition of the micromere cell surface has been examined by 125I labelling of intact cells followed by SDS-PAGE. In Arbacia punctulata, four high molecular weight (HMW) proteins are detected on the surface of isolated micromeres--but not on mesomere-macromere fractions. In Strongylocentrotus droebachiensis, a micromere-specific protein of 133 K molecular weight (MW) was identified. This 133 K protein binds to wheat germ agglutinin (WGA) but not to concanavalin A (conA). Lectin binding was studied using a new technique. The procedure involves the separation, by SDS-PAGE, of iodinated cell-surface proteins followed by their electrophoretic transfer to lectin-coated nitrocellulose membranes. Using this procedure, cell-type-specific surface proteins which are also lectin-binding-specific, were detected.

Animals↗
PubMed1984

[Heatstroke].

Heat stroke, heat exhaustion and heat cramps are the most important heat syndromes. Heat stroke must be recognized as a medical emergency. Inappropriate delay in diagnosis and treatment may lead to death caused by functional impairment or irreversible damage to almost every organ of the system. The history, clinical findings and outcome are described in four patients with heat injury during a 13-km military cross country race. Pathophysiology, complications, treatment and prevention of heat illness are discussed.

Adult↗
PubMed1983

Serum effects on the in vitro differentiation of sea urchin micromeres.

When micromeres isolated from the 16-cell stage of Strongylocentrotus purpuratus are cultured in sea water containing 3.5% horse serum, they produce spicules at approximately the same time as in normal development. The serum requirement of the micromeres has been investigated by adding serum at varying intervals after isolation or by pulsing the cells with serum at specific times during their in vitro development. The optimum time of serum addition for spicule formation is 36 h after fertilization (AF). Further delay in the addition of serum results in a reduction in the number of spicules formed in culture and a delay in the time at which they appear. A 1-h pulse of serum at 36 h AF is sufficient to initiate a response in some of the micromere aggregates. A 12-h pulse at 36 h AF produces the maximum number of spicules per culture. The critical period for serum addition, 36-48 h AF, corresponds to the time in the normal embryo at which the syncytial primary mesenchyme ring is formed. Electron micrographs of cultured cells demonstrate that micromeres cultured without serum until 48 h AF fail to form pseudopodial extensions and remain as rosette-like clusters of cells. If serum is present, extensive pseudopodial networks form which resemble the primary ring syncytium. These results suggest that serum acts to stimulate fused pseudopodial networks in cultures of micromeres and that the resulting syncytium is necessary for spicule formation.

Animals↗
PubMed1983

Fibronectin and laminin in the extracellular matrix and basement membrane of sea urchin embryos.

Fibronectin and laminin have been found in the extracellular matrix and in the basement membrane of sea urchin embryos during early development. These glycoproteins are also found on the cell surfaces of the outer epithelial layer and on the secondary mesenchyme cells within the blastocoel. The similarity of functions of the extracellular matrix and basement membrane is discussed, as is the similarity of their molecular components. These observations suggest the possibility that fibronectin and laminin form a continuous matrix surrounding the cells which links the outer ECM (hyaline layer) to the inner ECM (basement membrane). Such a network could coordinate the various activities of the embryo during early morphogenesis.

Animals↗
PubMed1983

Protein composition of the hyaline layer of sea urchin embryos and reaggregating cells.

The protein composition of the sea urchin embryo hyaline layer has been studied by 125I surface labeling. The electrophoretic patterns of iodinated proteins indicate that the composition of the hyaline layer is species and stage-specific. Dissociation of iodinated embryos removes some labeled proteins of apparent molecular weights of 290,000, 175,000, 145,000, 110,000, 70,000, and 50,000. The electrophoretic pattern of labeled proteins found in the intact embryo is reestablished on the surface of aggregates following reaggregation. The possible function of these proteins with respect to cell adhesion, cell-sorting behavior and morphogenesis is discussed.

Age Factors↗