Acute inflammation in foetal and adult sheep: the response to subcutaneous injection of turpentine and carrageenan.

Because of the small number of inflammatory cells found in skin wounds, it has been considered that foetal sheep are incapable of an adequate inflammatory response. The present study shows that subcutaneous injection of turpentine or carrageenan into foetal sheep consistently excites a severe cellular inflammatory reaction. At 75 days gestation the inflammatory cells are all macrophages.

Regulation of the avidity of integrin alpha 4 beta 7 by the beta 7 cytoplasmic domain.

Integrins are cell-surface heterodimeric receptors with adhesive and transmembrane signaling properties. Their cytoplasmic domains can affect receptor avidity, cytoskeletal association, and post-receptor occupancy events. The alpha 4 beta 7 integrin mediates cell adhesion to Peyer's patch high walled endothelial venules (HEV), VCAM, and CS-1/fibronectin.

Management of severe spasticity with intrathecal baclofen delivered by a manually operated pump.

Intrathecal baclofen abolishes spasticity in many patients with neurological diseases but there are few studies on its long-term effectiveness. Since 1986 a manually operated subcutaneous pump has been used to deliver baclofen intrathecally in 21 patients with a follow up of at least one year. Most patients had multiple sclerosis and all were wheelchair-bound.

Rapid tissue expansion for the development of rotational skin flaps in the distal portion of the hindlimb of dogs: an experimental study.

In phase I, tissue expanders were implanted subcutaneously over the lateral crural region of four dogs. The expanders were inflated daily to maintain a constant intraluminal pressure for 7 days. All animals tolerated the pressurized expanders well.

Cold stored femoral vessels as microvascular allografts: a preliminary study.

Cold stored femoral arteries or veins have been reinserted successfully as autografts into rabbits. The present study examines whether grafting with cold stored vascular allografts is equally successful. Rabbit femoral arteries and veins were stored at 4 degrees C for 4 weeks before insertion as allografts into unrelated animals.

The functional and structural effects of hypothermic storage on ischaemic arterial grafts.

The effects of hypothermic ischaemia on blood vessels are unknown. This study aimed to determine the 3 week patency rate and the pathology of 9 experimental groups of hypothermically stored ischaemic arteries and one control group in a rabbit femoral artery model. Ischaemia times were 0 h, 24 h, 1, 2, 4, 6, 8 and 10 weeks (Groups 1-8).

The establishment and continuous subculturing of normal human adult hepatocytes: expression of differentiated liver functions.

The use of normal adult liver hepatocytes in cell culture for biochemical, toxicological and pharmacological studies has been greatly limited owing to the loss of replicative capacity and differentiated liver function. This is contrary to the ability of the liver to regenerate following injury in vivo. This suggests that liver "stem" or "transitional" hepatocytes exist that upon proper stimulus divide and differentiate into mature hepatocytes.

Retinoic acid mediates post-transcriptional regulation of keratin 19 mRNA levels.

Stratified squamous epithelia have been shown to preferentially express a site-specific pattern of keratin intermediate filaments. Retinoic acid (RA) is known to modulate expression of the basal cell keratins K19 and K5. Expression of these genes is dependent on extracellular RA concentration.

Improved compensation of atmospheric turbulence effects by multiple adaptive mirror systems.

Optical wave-front propagation in a layered model for the atmosphere is analyzed by the use of diffraction theory, leading to a novel approach for utilizing artificial guide stars. Considering recent observations of layering in the atmospheric turbulence, the results of this paper indicate that, even for very large telescopes, a substantial enlargement of the compensated angular field of view is possible when two adaptive mirrors and four or five artificial guide stars are employed. The required number of guide stars increases as the thickness of the turbulent layers increases, converging to the conventional results at the limit of continuously turbulent atmosphere.

Sidelobe reduction in optical signal processing.

A general procedure is introduced for sidelobe and noise reduction in optical or digital signal processing. Specific examples of sidelobe reduction in imaging are presented. It is demonstrated that the new method provides superior spatial resolution to previously proposed sidelobe-reduction techniques.

Cloning and expression of mouse integrin beta p(beta 7): a functional role in Peyer's patch-specific lymphocyte homing.

Lymphocytes express integrin receptors, termed lymphocyte Peyer's patch high endothelial venule (HEV) adhesion molecules (LPAMs), that mediate their organ-specific adhesion to specialized HEVs found in mucosal lymphoid organs (Peyer's patches). LPAM-1 consists of a murine integrin alpha 4 noncovalently associated with integrin beta p. Here, we describe the cloning and expression of a mouse cDNA encoding beta p, which is an 806-amino acid transmembrane glycoprotein.

Wound healing in foetal sheep: a histological and electron microscope study.

A study was made of the healing of excised, unsutured and sutured skin wounds in foetal sheep of 75, 90 and 120 days gestation and of wounds in newborn lambs and adult ewes. Foetal and postnatal wounds were found to heal in a very similar way. At each stage of development studied, excised wounds contract rapidly and histological and electron microscope examination demonstrates formation of granulation tissue and its maturation to scar tissue in all types of wound.

Variable expression of retinoic acid receptor (RAR beta) mRNA in human oral and epidermal keratinocytes; relation to keratin 19 expression and keratinization potential.

Previous studies have revealed that the cells that form the different regions of the oral and epidermal stratified squamous epithelia represent a number of intrinsically distinct keratinocyte subtypes, each of which is developmentally programmed to preferentially express a particular pattern of keratins and type of suprabasal histology. Retinoic acid (RA) is known to modulate stratified squamous epithelial differentiation, including expression of the basal cell keratin K19 and the suprabasal keratins K1/K10 and K4/K13. We have found that all keratinocyte subtypes are similar in their steady state levels of RAR alpha and RAR gamma mRNAs in culture and that these levels are only minimally affected by RA.

Near-field optical disk recording for very high data density.

The use of subwavelength near-field apertures opens the possibility of optical dish data density increases in excess of 4 orders of magnitude.

Role of photon statistics in energy-efficient optical computers.

One of the limiting factors in the operation of highly energy-efficient optical computers is the fluctuation in the rate of photon detection events. Squeezed light technology, which appeared to be a possible way to mitigate this fluctuation, is shown to be of limited utility in this field.

Abnormal expression of retinoic acid receptors and keratin 19 by human oral and epidermal squamous cell carcinoma cell lines.

We have analyzed the expression of the three retinoic acid receptor (RAR) (alpha, beta, gamma) mRNAs and the intermediate filament protein keratin 19 (K19) mRNA in cell lines cultured from oral and epidermal human squamous cell carcinoma (SCC) and from benign, hyperplastic, and hyperkeratotic (leukoplakia) lesions arising in various regions of the oral cavity. Seven of the SCC lines were derived from tumors arising in regions of the oral cavity in which the normal epithelial cells (keratinocytes) express RAR beta transcripts. Seven of the nine SCC lines tested did not exhibit detectable RAR beta mRNA levels, even in response to addition of retinoic acid (RA).