PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Subcutaneous Tissue”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 469 records · Page 26Linked to original sources
PubMed1995

Electrical stimulation of the sciatic nerve alters neuropeptide content and lymphocyte migration in the subcutaneous tissue of the rat hind paw.

To study the possible mechanism by which peripheral nerves mediate immune responses in target tissues, electrical stimulation of the sciatic nerve was combined with subcutaneous microdialysis of the hind paw. Following unilateral stimulation of the sciatic nerve, an ipsilateral rise in substance P and a bilateral rise in VIP levels were observed in dialysate samples from experimental vs control animals. Electrical stimulation of the sciatic nerve induced a marked hyperemia and swelling of the ipsilateral paw. Quantitative immunocytochemical analysis of paraffin-embedded sections of the hind foot pads demonstrated T lymphocyte migration ipsilateral to the stimulated nerve. These findings suggest that peripheral nerves can directly modulate local immune and inflammatory responses.

Animals↗
PubMed2005

Evaluation of biodegradable synthetic scaffold coated on arterial prostheses implanted in rat subcutaneous tissue.

Polyester arterial prostheses impregnated with various synthetic biodegradable materials and with gelatin were implanted subcutaneously in rats for 3-180 days. The inflammation was assessed by quantifying the activity of alkaline phosphatase and by histology. The degradation of the scaffold materials was determined by scanning electron microscopy (SEM), size exclusion chromatography (SEC), and differential scanning calorimetry (DSC). The alkaline phosphatase activity induced by the polymer-impregnated grafts was similar to that induced by the non-impregnated controls during most of the post-implantation periods. Histological studies revealed that the acute inflammatory response was moderate to mild and was similar for all types of specimens, except for the gelatin-impregnated grafts that induced a severe acute inflammation during the first 2 weeks post-implantation. At 4 and 6 months, significant disintegration of the scaffold was observed, accompanied by enhanced tissue infiltration and a reactivation of the acute inflammatory phase. Linear and exponential degradation rates of the synthetic polymers were described. The relative degradation rates of the biodegradable polymers were ranked as following: PLLACL > PDLLA > PLLA > PCEL. In conclusion, biodegradable polymers may provide an option as sealant/scaffolding materials for vascular prosthesis. It is suggested that the degradation rate of the polymer scaffolding materials should be higher to achieve early healing while without inducing strong inflammation.

Absorbable Implants↗
PubMed1996

The abdominal subcutaneous tissue: computed tomographic, magnetic resonance, and anatomical observations.

We have studied the fasciae of the abdominal subcutaneous layer by analyzing axial CT images taken at a level immediately superior to the iliac crests in 20 adult female patients. The pattern of the fascial planes seen at this level was compared with those seen on MRI and dissected cadaveric sections. We have demonstrated a circumferential subcutaneous fascial plane that divides the subcutaneous fat into a single superficial fat compartment and a single deep fat compartment.

Abdominal Muscles↗
PubMed1979

'Distensibility' of the papaverine-relaxed vascular bed in human subcutaneous tissue.

The effect of an increase in vascular transmural pressure upon the blood flow in two subcutaneous vascular beds, maximally dilated by papaverine was studied in 6 healthy humans. Blood flow was measured on the dorsum of the hand and at the lateral malleolus by the local 133Xe washout technique. Increase in vascular transmural pressure was induced by lowering the labelled area various distances below heart level. Lowering the area caused an increase in blood flow. The increase was less pronounced in the legs than in the hand. As arterial perfusion pressure head remained constant during lowering, this indicates that the relative decrease in vascular resistance was smaller in the leg than in the hand. Experimental edema did not influence the relative decrease in vascular resistance. The results suggest that 'distensibility' of the resistance vessels is smaller in the leg than in the hand. This might be due to a structural adaptation of the vascular wall in vessels often subjected to increased hydrostatic pressure.

Blood Pressure↗
PubMed2006

Pathological demonstration of rapid involvement into the subcutaneous tissue in a case of fatal hydrofluoric acid burns.

We report an autopsy case of a man who suffered accidental chemical burns following exposure to 60% hydrofluoric acid. The extent of the burns covered about 30% of his body surface, and cardiopulmonary arrest occurred about 30min after the exposure. At autopsy, the skin of the affected area showed greenish gray or black coloring with thin circumferential erythema, and this discoloration extended as far as the periosteum of the skull. However, such discoloration was not found on the mucosa of the airway or the gastrointestinal tract. Microscopically, severe liquefactive necrosis was already evident on the skin. Elastic fibers within the dermis were completely lost, and the entire wall of large vessels within the subcutaneous layer was already severely affected. Blood analysis in the emergency room showed hypocalcemia, and the levels of fluoride ions in the postmortem blood and urine showed extremely high values. However, fewer fluoride ions were detected from the lung tissue. The present case suggests that the hydrofluoric acid had immediately penetrated down into the deep layer of the skin, thereby involving the large vessels present within the subcutaneous layer. These pathological findings of the skin seen in the present case explain the mechanism behind the rapid dissemination of fluoride ions which entered the bloodstream from damaged arteries, resulting in the development of acute toxicity.

Accidents, Occupational↗
PubMed1999

Long-term observation of subcutaneous tissue reaction to synthetic auditory ossicle (Bioceram) in rats.

To evaluate biocompatibility to tissue in long-term implantation, Bioceram discs made of aluminum oxide (Al2O3) were implanted subcutaneously within the interscapular region of 64 rats for six to 20 months. Histological sections stained with haematoxylin and eosin (H&E) and the surface of the implant material were observed using light microscopy. Different cell types and the thickness of fibrous capsules surrounding the implants were examined quantitatively by light microscopy. Small numbers of macrophages (2.8 +/- 0.7%) and lymphocytes (2.7 +/- 0.9%) were observed at six months after implantation, gradually decreasing to zero at 16, 18 and 20 months. Neither neutrophils nor foreign body giant cells were seen in any specimens. The thickness of fibrous capsules surrounding the implants was closely related to the shape of the implant, but there was no significant change between six and 20 months after implantation. No change in Bioceram surfaces were observed under stereoscopic microscopy from six to 20 months after implantation. The study results indicate that Bioceram is a satisfactory biocompatible material for reconstructive surgery from the viewpoint of long-term tissue response. Present results of experiments with Bioceram are also compared to previous results with Apaceram and different tissue responses of the two materials are discussed.

Aluminum Oxide↗
PubMed1999

Accessible xenografts of human synovium in the subcutaneous tissues of the ears of SCID mice.

This work was undertaken to examine whether human synovium could be engrafted into subcutaneous pouches in the ears of severe combined immunodeficient (SCID) mice. Synovium was transplanted into surgically constructed ear pouches. The grafts were examined by histological and immunohistochemical methods after varying periods after engraftment, or after percutaneous injection of TNF-alpha. Normal, osteo-arthritic and rheumatoid synovium was engrafted successfully in subcutaneous ear pouches. The general morphology and cellular compositions of xenografts were retained including human endothelial cells. In rheumatoid xenografts, macrophages, fibroblasts and lymphocytes persisted for at least 4 weeks. Vascular expression of intercellular adhesion molecule-1 (ICAM-1) was maintained but expression of vascular adhesion molecule-1 (VCAM-1), E-selectin and MHC class II diminished with time. Percutaneous injection of TNF-alpha induced up-regulation of VCAM-1. Human synovium can be engrafted into subcutaneous ear pouches in SCID mice. The xenografts are accessible and respond to injection of a pro-inflammatory cytokine.

Adult↗
PubMed1984

Fixation of extradural catheters by means of subcutaneous tissue tunnelling.

In 100 patients treated for chronic pain, extradural opioids were administered by means of catheters which were tunnelled subcutaneously. Seventy-three per cent of patients needed only one catheter and 15% had a catheter in place for more than 100 days, the longest being for 434 days. In only 18 patients was the catheter displaced accidentally from the extradural space. There were no instances of extradural infection, although in three patients the tunnel became infected. We conclude that fixation of extradural catheters by subcutaneous tunnelling is a simple method which provides adequate security in clinical practice.

Adult↗
PubMed1983

Norfloxacin penetration into subcutaneous tissue cage fluid in rabbits and efficacy in vivo.

The activity of norfloxacin was studied in vivo with steel net cages implanted subcutaneously in rabbits. Four weeks after implantation, two of four cages in each animal were inoculated with a strain of Escherichia coli (seven animals) or Klebsiella pneumoniae (six animals). Four animals in each group received oral treatment with norfloxacin for 7 days. Treatment was started 18 h after inoculation of the cages. Peak concentrations above the in vitro minimal inhibitory concentrations for the strains used were achieved in the fluid of 14 of 16 of the infected cages after the first norfloxacin dose. The penetration of norfloxacin into both infected and uninfected tissue cage fluid was significantly higher on treatment days 3 and 7 than on treatment day 1. No difference was observed between the concentrations in uninfected and infected cage fluids or between cage fluids infected with different organisms. The viable counts of E. coli and K. pneumoniae decreased from 2 X 10(3) to 2 X 10(8) CFU/ml of cage fluid to less than 10 CFU/ml in 10 of the infected cage fluids 12 h after the last dose of norfloxacin. Fluid from four cages still containing low numbers of viable bacteria at that time became free from bacteria (less than 10 CFU/ml) 1 to 4 days later. No regrowth was found in any cage fluid 7 days after the treatment period. The viable counts of E. coli or K. pneumoniae in five untreated control animals did not decrease during 8 to 14 days after inoculation of cage fluid. In comparison with cephalosporins and aminoglycosides studied previously with the same experimental method, norfloxacin penetrated better into cage fluid and more effectively reduced the viable counts of the organisms.

Animals↗
PubMed1981

Influence of serum protein binding and mode of administration on penetration of five cephalosporins into subcutaneous tissue fluid in humans.

The penetration of five cephalosporins into interstitial fluid was investigated by a new method employing cotton threads implanted subcutaneously. Penetration after short bolus injections, calculated as area under interstitial fluid level curve divided by area under serum level curve x 100, was 47.0% for cephradine, 30.6% for cefuroxime, 26.7% for cefotaxime, 24.6% for cefoxitin, and 9.6% for cefoperazone. There was an inverse correlation between the degree of penetration and serum protein binding with r = -0.97. The area under interstitial fluid level curves was the same whether the drugs were administered as short bolus injections or short time infusions.

Adult↗
PubMed2004

A hyaluronan-based nerve guide: in vitro cytotoxicity, subcutaneous tissue reactions, and degradation in the rat.

We investigated possible cytotoxic effects, biocompatibility, and degradation of a hyaluronan-based conduit for peripheral nerve repair. We subjected the conduits to an in vitro fibroblast cytotoxicity test and concluded that the conduits were not cytotoxic. Subsequently, we implanted the conduits subcutaneously in rats, in order to investigate tissue reactions and biodegradation. Initially, a fibrin matrix was formed around the material, while the surroundings were relatively quiet. Macrophages (MØ) migrated to the conduits and formed giant cells next to the material after 5 days. The maximum presence of MØ was found after 3-6 weeks. The appearance of MHC class II cells showed a similar pattern. Highest numbers of giants reached a maximum after 6-12 weeks. Angiogenesis was started in the surroundings of the hyaluronan-based conduit within a few days. Massive ingrowth of blood vessels into the biomaterial was found after 6 weeks as well as cellular ingrowth into the lumen of the tube. At that time the tubular structure of the conduit was lost and loose biomaterial fibers were observed. The results show that a hyaluronan-based conduit is not cytotoxic and shows good biocompatibility. Such a conduit may be suitable as a guide in peripheral nerve repair.

Adjuvants, Immunologic↗
PubMedDate not supplied

[An x-ray study of the subcutaneous tissue using an artificial method of providing contrast].

The paper is concerned with the main methodological principles and potentialities of a radiocontrast study of subcutaneous fat to detect pathological changes in it. The proposed method consists in slow administration in the middle fat layers of 20-25% solution of verografin from not less than two points, and subsequent roentgenography in a necessary projection. The method was used in 15 patients with various orthopedic diseases for diagnosis of inflammatory, tumorous and degenerative-dystrophic diseases.

Adipose Tissue↗
PubMed1999

Histological and compositional evaluations of three types of calcium phosphate cements when implanted in subcutaneous tissue immediately after mixing.

To evaluate the soft tissue response of calcium phosphate cement (CPC), consisting of an equimolar mixture of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA) under conditions close to those encountered in actual surgical procedures, we implanted three types of CPC [conventional CPC (c-CPC), fast-setting CPC (FSCPC), and antiwashout type FSCPC (aw-FSCPC; formerly called nondecay type FSCPC or nd-FSCPC)] subcutaneously in the abdomens of rats immediately (1 min) after mixing. At 1 week after surgery, histological examination and compositional analysis were performed using light microscopy and powder X-ray diffraction (XRD), respectively. The implanted c-CPC was crumbled completely, whereas FSCPC and aw-FSCPC retained their shape. Large vesicles containing copious inflammatory effusion were subcutaneously formed around the c-CPC. Histologically, many foreign-body giant cells were collected around the c-CPC, and moderate inflammatory cell infiltration was observed at 1 week after surgery. In contrast, the FSCPC and aw-FSCPC were covered with a thin layer of granulation tissue that included few giant cells and presented slight inflammatory cell infiltration, and no effusion was observed. The XRD analysis of the c-CPC revealed the presence of some unreacted DCPA even 1 week after implantation, whereas almost no DCPA was found in the FSCPC or aw-FSCPC. In conclusion, it was found that CPC does not always show excellent tissue response. When c-CPC is implanted subcutaneously in rats immediately after mixing, it fails to set and causes a severe inflammatory response. Therefore, the type of CPC should be chosen according to the clinical particulars. CPC should be used in a manner that assures its setting reaction. We recommend the use of FSCPC and aw-FSCPC for surgical applications, such as orthopedics, plastic and reconstructive surgery, and oral and maxillofacial surgery, where the cement might otherwise crumble due to the pressure before setting.

Animals↗