Autocatalytic membrane conductance and memory.

A basic characteristic of biological memory is that it has a graded duration, which, even for so-called short-term memory, can vary from minutes to days (i.e. over about three orders of magnitude), depending on the training protocol, which one can think of as determining the "strength" of the memory.

Differential effects of the cytoplasmic domains of cell adhesion molecules on cell aggregation and sorting-out.

Cell adhesion molecules (CAMs) are cell surface glycoproteins that play important roles in morphogenesis and histogenesis, particularly in defining discrete borders between cell populations. Previous studies have suggested that the cytoplasmic domains of CAMs play a significant role in their adhesion properties. These domains may also be involved in regulating other cellular interactions, such as those involved in the sorting-out of cells to form tissues.

cDNAs of cell adhesion molecules of different specificity induce changes in cell shape and border formation in cultured S180 cells.

The liver cell adhesion molecule (L-CAM) and N-cadherin or adherens junction-specific CAM (A-CAM) are structurally related cell surface glycoproteins that mediate calcium-dependent adhesion in different tissues. We have isolated and characterized a full-length cDNA clone for chicken N-cadherin and used this clone to transfect S180 mouse sarcoma cells that do not normally express N-cadherin. The transfected cells (S180cadN cells) expressed N-cadherin on their surfaces and resembled S180 cells transfected with L-CAM (S180L cells) in that at confluence they formed an epithelioid sheet and displayed a large increase in the number of adherens and gap junctions.

Requirement for integrins during Drosophila wing development.

The position-specific (PS) integrins of Drosophila are highly homologous to vertebrate integrins, most of which are cell-surface receptors for extracellular matrix components. Integrins are heterodimers, each consisting of noncovalently associated alpha- and beta-subunits. As for the subfamilies of vertebrate integrins, the same beta-subunit is found in both Drosophila PS integrins, combined with a specific alpha-subunit to generate either a complete functional PS1 or PS2 integrin.

The multislice cylinder: a new approach to quantification of cardiac single photon emission tomography.

A new method of displaying SPECT (single photon emission tomography) thallium-201 images is described in which cardiac activity is constructed as a cylindrical map. Exercise thallium-201 scintigrams from 52 patients with known or suspected coronary artery disease are analysed by this technique and a simplified severity score devised.

Transient cortical blindness with occipital lobe epilepsy.

Three youths with occipital seizures and intermittent visual loss are presented. All three had occipital epileptiform discharges. Visual loss occurred during seizures and improved with anticonvulsant medication.

Alterations in organization of phospholipids in erythrocytes as factor in adherence to endothelial cells in diabetes mellitus.

Erythrocytes from patients with diabetes mellitus exhibit increased adherence to cultured human vascular endothelial cells. We investigated the alterations in erythrocyte surface characteristics that may contribute to their abnormal adherence. The organization of phospholipids in the lipid bilayer, as determined by phospholipase A2 treatment and chemical labeling with fluorescamine and trinitrobenzene sulfonic acid (TNBS), is altered in erythrocytes from diabetic patients.

Increased adherence of oxidant-treated human and bovine erythrocytes to cultured endothelial cells.

Bovine erythrocytes, which normally lack phosphatidyl choline in their membranes, when treated with either H2O2 or diamide (1-3 mM), showed a partial appearance of phosphatidyl ethanolamine (PE 40%) and phosphatidyl serine (PS, 30-33%) in the external leaflet of the bilayer and a concomitant increased (four- to five-fold) propensity to adhere to cultured bovine aortic endothelial cells. Similar treatment of normal human erythrocytes caused an alteration in the organization of the phospholipid bilayer and also resulted in their increased adherence to endothelial cells derived either from human umbilical vein or bovine aorta. Treatment of RBCs with H2O2 at low concentration (0.

Foster child health care supervision policy.

Foster children represent a high-risk group for physical, emotional, and social health problems, yet few federal or state policies explicitly address foster child health. This article reviews foster child health and the legal background for policy, then discusses components of a comprehensive health care supervision program.

Separation of luminal and abluminal membrane enriched domains from cultured bovine aortic endothelial cells: monoclonal antibodies specific for endothelial cell plasma membranes.

Two kinds of membrane (luminal and abluminal membrane domains) fractions have been isolated from bovine aortic endothelial cells by fractionation of whole cell homogenate on discontinuous sucrose density gradients. The luminal membrane domain was enriched 12-16-fold for angiotensin-converting enzyme activity and 8-10-fold in alkaline phosphatase activity. The abluminal membrane domain displayed an enrichment of 8-fold in (Na+ + K+)-ATPase activity.

MRI of central nervous system: early clinical results.

In patients with central nervous system problems, a comparison of the results obtained with high-field MRI (1.5 T) to those achieved with more conventional imaging studies, primarily CT, reveals significant improvement in the demonstration of various abnormalities by MRI (56.5%), with increased specificity in some (29.

The capacity of chondrocytes to respond to serum is enhanced by organ culture in the absence of serum, stimulated by serum, and modified by ascorbate.

Cartilage slices maintained in organ culture have been shown to develop an enhanced capacity to respond to serum. The response was measured at the initiation of culture and after 3 and 7 days of culture in medium containing an inhibitor of DNA synthesis and 0, 1, or 16% serum. At these times, cartilage slices were washed to remove serum and inhibitor, and then exposed to various concentrations of serum for evaluation of DNA and proteoglycan synthesis.

Changes in responsiveness to newborn pups in pregnant, nulliparous golden hamsters.

Virgin female hamsters were mated and tested once daily for maternal retrieving behavior beginning on days 0, 5, 9, 13, 15, of the 16 day gestation period to determine if responsiveness toward newborn pups changes as pregnancy proceeds. Upon initial exposure to 3 newborn pups, only a small percentage of early-to-mid-pregnant females exhibited maternal retrieving behavior spontaneously. In contrast, over half of the 15 day pregnant females displayed retrieving during the first test.

Tarsal tunnel syndrome: a manifestation of systemic disease.

In many respects, tarsal tunnel syndrome is analogous to carpal tunnel syndrome. Despite this fact, tarsal tunnel syndrome has lagged far behind its counterpart in recognition and understanding. Thought of as a local compression phenomenon, reports of systemic associations are now being seen with increased frequency.

Biochemical, genetic, psychometric, and neuropsychological studies in heterozygotes of a family with globoid cell leucodystrophy (Krabbe's disease).

Detection of a patient suffering from Krabbe's disease led to carrier screening in his family. Determination of galactosylceramide beta-galactosidase activity revealed the occurrence of two different alleles among the carriers of the same family. Heterozygotes and their noncarrier relatives were studied using psychometric and neuropsychological tests under blind conditions.

Modified treatment of thumb ray dysplasia: a case report.

The abnormality of the carpometacarpal joint and lack of opposition are two of the more difficult components to treat in the thumb ray dysplasia syndrome. A trapezium arthroplasty and an extensor indicis proprius opponensplasty were used in a typical case. Active opposition was obtained.

Biochemical, psychometric, and neuropsychological studies in heterozygotes for various lipidoses. Preliminary results.

A sample of 38 clinically unaffected carriers for various lipidoses and their noncarrier relatives was studied with biochemical, psychological, and neuropsychological tests under blind conditions. The largest group of carriers was that for metachromatic leucodystrophy (MLD). The mean activity of arylsulphatase A or cerebroside sulphatase in the obligate carriers was 25%-30% of the control values, some heterozygotes showing little more activity than MLD patients.

Malignant hemangioendothelioma (angiosarcoma) of the salivary gland: an ultrastructural study.

A case of malignant hemangioendothelioma (angiosarcoma) of the submaxillary salivary gland is reported and its microscopic and ultrastructural features are described and compared to previous reports of angiosarcoma arising in other locations. These tumors may often contain areas of solid sheets of cells without vascular characteristics and may be confused with poorly differentiated carcinoma or other sarcomas. The ultrastructural features of angiosarcoma are compared to other poorly differentiated tumors.