SEARCH · PubMed Health

Results for “Subcutaneous”

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 235 records · Page 13Linked to original sources

PubMed1991

Precooling prevents overheating of subcutaneous fat in the use of RF capacitive heating.

The usefulness of precooling subcutaneous tissue in the hyperthermic treatment of deep-seated human tumors with capacitive application of radio-frequency (RF) was investigated. A capacitive hyperthermia unit operated at 8 MHz of radiofrequency was used to heat deep-seated human tumors. The electrode surfaces were covered with flexible vinyl sheets and the space between the electrode and the vinyl sheets perfused with 0.4% saline. The temperature of the saline was controlled by circulating the saline through built-in heat exchangers. The depth of heating was controlled by pairing electrodes of different diameters. When subcutaneous fat was less than 1 cm thick, various deep-seated tumors could be heated to a therapeutic temperature without significant discomfort in the subcutaneous tissue as long as the skin was properly cooled with the cold saline bolus. However, the same cooling method could not prevent the occurrence of pain in subcutaneous tissue in obese patients. The pain usually developed when the temperature of subcutaneous fat 1-2 cm below the skin surface exceeded 42 degrees C. We observed that cooling the human skin surface with 10 degrees C bolus for 20 min could substantially lower the temperature of fat as deep as 2.0-2.5 cm. Therefore, when the subcutaneous tissue was precooled with 10 degrees C saline for 20 min or longer before heating, it was possible to prevent successfully the overheating of subcutaneous fat as thick as 2.0-2.5 cm and to raise the temperature of deep-seated tumors to therapeutic levels.

Adipose Tissue↗

PubMed2002

Subcutaneous microfabricated surfaces inhibit epithelial recession and promote long-term survival of percutaneous implants.

The long-term success of percutaneous devices is compromised by problems such as infection, mechanical avulsion and epithelial downgrowth. The objective of this study was to test the effects of microfabricated surfaces on tissue integration and long-term survival of percutaneous implants, using a modified implant design and a two-stage surgical method. Hexagonal titanium-coated epoxy implants were constructed with separate subcutaneous and percutaneous components, so that the effects of surface topography on connective tissue could be separated from the effects on epithelium. Subcutaneous components with 30-microm-deep micromachined grooves, 120-microm-deep tapered pits, or smooth control surfaces were secured to the calvarial bone of rats by a titanium pin. After 8 weeks, a percutaneous smooth-surfaced component was secured to the subcutaneous component. Dental impression materials were used to make models of the components and adjacent tissues at weekly intervals and tissue recession around the implants was measured. Some implants were removed at intervals up to 24 weeks and processed for histology. Connective-tissue ingrowth and mineralized tissue were noticed on the micromachined surfaces, whereas a thick capsule and epithelial downgrowth were observed on smooth control surfaces. On all implants, recession occurred most rapidly in the first 3 weeks, but was significantly reduced relative to the smooth controls only on implants with micromachined grooved subcutaneous surfaces (p<0.05). In addition, the time before failure was significantly (p<0.05) longer for implants with grooved subcutaneous surfaces than implants with smooth and pitted subcutaneous surfaces. This study indicated that an impression technique could be used to monitor tissue recession on percutaneous devices, and that micromachined grooved surfaces located subcutaneously improved the performance and longevity of percutaneous devices by promoting tissue integration.

Animals↗

PubMed1996

Complications associated with pectoral cardioverter-defibrillator implantation: comparison of subcutaneous and submuscular approaches. Worldwide Jewel Investigators.

OBJECTIVES: The aim of this study was to compare complications in a large cohort of patients undergoing pectoral cardioverter-defibrillator implantation with a subcutaneous or submuscular approach. BACKGROUND: Pectoral placement of implantable cardioverter-defibrillator (ICD) pulse generators is now routine because of downsizing of these devices. subcutaneous implantation has been advocated by some because it is a simple surgical procedure comparable to pacemaker insertion. Others have favored submuscular insertion to avoid wound complications. These surgical approaches have not been compared previously. METHODS: The subjects for this study were 1,000 consecutive patients receiving a Medtronic Jewel ICD at 93 centers worldwide. Cumulative follow-up for all patients was 633.7 patient-years, with 64.9% of patients followed up for > or = 6 months. The complications evaluated were erosion, pocket hematoma, seroma, wound infection, dehiscence, device migration, lead fracture and dislodgment. RESULTS: Subcutaneous implantation was performed in 604 patients and submuscular implantation in the remaining 396. The median procedural times were shorter for subcutaneous implantation (p = 0.014). In addition, the cumulative percentage of patients free from erosion was greater for subcutaneous implantations (p = 0.03, 100% vs. 99.1% at 6 months). However, lead dislodgment was more common with subcutaneous implantations (p = 0.019, 2.3% vs. 0.5% at 6 months) and occurred primarily during the first month postoperatively. Overall, there were no significant differences in cumulative freedom from complications between groups (4.1% vs. 2.5%, p = 0.1836). CONCLUSIONS: Subcutaneous pectoral implantation of this ICD can be performed safely and has a low complication rate. This approach requires a simple surgical procedure and, compared with the submuscular approach, is associated with shorter procedure times and comparable overall complication rates. However, early follow-up is important in view of the increased lead dislodgment rate.

Aged↗

PubMed1997

Noradrenaline-induced lipolysis in isolated mesenteric, omental and subcutaneous adipocytes from obese subjects.

OBJECTIVE: The action of noradrenaline on human mesenteric, omental and subcutaneous adipocytes was compared. We also determined whether regional differences in the noradrenaline-effect were linked to variations in adrenoceptor subtype function. DESIGN: The lipolytic effects of different concentrations of noradrenaline (beta 1-, beta 2-, beta 3- and alpha 2-adrenoceptor agonist), isoprenaline (beta 1-, beta 2- and beta 3-adrenoceptor agonist) and selective beta 1-, beta 2- and beta 3-adrenoceptor agonists (dobutamine, terbutaline and CGP 12177, respectively) were studied in adipocytes isolated from the three adipose tissue regions in the same subject. In addition, the effect of the alpha 2-adrenoceptor antagonist, yohimbine, was studied on noradrenaline-induced glycerol release. SUBJECTS: Thirteen otherwise healthy obese subjects (nine females, four males). RESULTS: The noradrenaline-induced lipolytic response did not differ between omental and mesenteric adipocytes but was 50% higher than in subcutaneous adipocytes (P < 0.05). Furthermore, noradrenaline sensitivity and intrinsic activity (in relation to isoprenaline) were higher in the two visceral fat cells than in the subcutaneous fat cells. The intrinsic activity of noradrenaline increased close to that of isoprenaline when yohimbine was added to the incubation system. Isoprenaline sensitivity was five times higher in the two visceral fat cells than in the subcutaneous fat cells. For CGP 12177, sensitivity and intrinsic activity did not differ between mesenteric and omental adipocytes, but was higher in these two regions when compared to subcutaneous adipocytes. For dobutamine and terbutaline no significant regional differences were found. CONCLUSION: beta 3-adrenoceptor action is enhanced and alpha 2-adrenoceptor action is decreased in both mesenteric and omental adipocytes as compared to subcutaneous adipocytes. However, the two visceral fat depots show no difference in adrenoceptor function. The difference in beta 3- and alpha 2-adrenoceptor function might explain why noradrenaline induced lipolysis is increased in the two visceral fat depots, as compared to the subcutaneous fat depot.

Adipocytes↗

PubMed2001

Distribution of valproate to subdural cerebrospinal fluid, subcutaneous extracellular fluid, and plasma in humans: a microdialysis study.

We sought to study the time course of the distribution of valproate (VPA) to subdural cerebrospinal fluid (CSF) in relation to subcutaneous extracellular fluid (ECF) and plasma after a single oral dose and to study the distribution to these three compartments under steady-state conditions. Microdialysis was used to estimate unbound VPA concentrations in subdural CSF and subcutaneous ECF, and blood samples were drawn for estimation of total and unbound VPA plasma concentrations in four patients with drug-resistant partial epilepsy undergoing presurgical evaluation with subdural EEG monitoring. Three patients were given a single oral dose of VPA, and one patient was receiving regular VPA treatment. VPA was analyzed by gas chromatography with flame ionization detection. The distribution of VPA to subdural CSF was rapid (Tmax, 3.5 h in two patients and 5.5 h in one patient) and subject to a minor delay in all three patients compared with that in the subcutaneous tissue ECF (Tmax, 2.5 h in all three patients), which in turn exhibited no evidence of a distribution delay compared with plasma. Subdural CSF levels of VPA were slightly lower than subcutaneous ECF levels (mean ratio, 0.78) and unbound plasma levels (mean ratio, 0.91). VPA rapidly enters the subdural CSF in unbound concentrations marginally lower than those obtained in subcutaneous ECF and plasma. These findings provide a pharmacokinetic rationale for acute administration of VPA. The good correlation between VPA concentrations in subcutaneous ECF and subdural CSF indicates that estimation of unbound VPA concentrations in subcutaneous tissue using microdialysis sampling has the potential to be useful for monitoring purposes.

Administration, Oral↗

PubMed2000

Lipoprotein lipase steady-state mRNA levels are lower in human omental versus subcutaneous abdominal adipose tissue.

Adipose tissue synthesizes lipoprotein lipase (LPL), which helps in the postprandial clearance of triglyceride-rich lipoproteins. Because visceral adipose tissue is generally accepted as the most important metabolic tissue, we sought to verify whether there are regional differences in the expression of LPL. Samples of adipose tissue from subcutaneous and omental fat deposits were obtained from 20 adults undergoing surgery. Total adipose tissue LPL activity was measured using a conventional radioactive substrate assay. Steady-state levels of LPL mRNA were assessed using the very sensitive RNase protection assay technique with 18S ribosomal RNA as an internal control. A correlation was demonstrated between LPL activity levels in subcutaneous and omental tissue (r = .72; P < .01) and between mRNA levels at both sites (r = .47, P = .04). LPL mRNA levels were significantly lower in omental compared with subcutaneous depots (omental v subcutaneous, 1.7 +/- 0.7 v 2.1 +/- 0.7 arbitrary units [AU] over 18S, P < .05). In paired comparisons, LPL mRNA levels in omental adipose tissue were, on average, 20% +/- 7% (range, -57% to +9.0%) lower than the levels measured in subcutaneous adipose tissue (P < .05). In conclusion, these data suggest that subcutaneous adipose tissue is a reliable surrogate of the expression (activity and mRNA) of LPL in omental adipose tissue, even though omental depots express proportionally less LPL than subcutaneous depots.

Abdomen↗

PubMed1998

Measurement and modeling of the transient difference between blood and subcutaneous glucose concentrations in the rat after injection of insulin.

The kinetics of the fall in subcutaneous fluid glucose concentration in anesthetized rats (n = 7) after intravenous injection of insulin (0.5 units/kg) was studied by using 5 x 10(-4) cm2 active area, <150-sec 10-90% response time, amperometric glucose sensors. The onset of the decline in the subcutaneous glucose concentration was delayed and statistically different (P < 0.001) from that in blood (8.9 +/- 2.1 min vs. 3.3 +/- 0.5 min). Similarly, the rate of drop in glucose concentration between 6 and 20 min after the insulin injection was different for subcutaneous tissue (3.9 +/- 1.3 mg.dl-1. min-1) and blood (6.8 +/- 2.0 mg.dl-1.min-1) (P = 0.003). The hypoglycemic nadir in subcutaneous fluid occurred 24.5 +/- 6.8 min after that in the blood (P < 0.001). A "forward" mass-transfer model, predicting the subcutaneous glucose concentration from the blood glucose concentrations and an "inverse" model, predicting the blood glucose concentration from the subcutaneous glucose concentration were derived. By using an algorithm based on the latter, the average discrepancy between the measured blood glucose concentration and that estimated from the subcutaneous measurement through the entire 4-hr experiment was reduced from 22.9% to 11.1% (P = 0.025). The maximum discrepancy during the 40-min period after the injection of insulin was reduced from 84.1% to 29.3% (P = 0.006).

Algorithms↗

PubMed1998

Atypical subcutaneous fatty tumors: a review of 37 referred cases.

We reviewed 37 referred, atypical, subcutaneous fatty tumors. There was a male preponderance (28:9). The median age was 51.5 years (26-83); the median duration of symptoms was 18 months (three weeks to 35 years); the median size was 5.5 cm (1.5-20) and the posterior cervico-dorsal areas (17 cases) was the commonest location. We divided tumors into five histological categories: (1) subcutaneous fibrolipomas with slight fibroblastic atypia (five cases); (2) subcutaneous spindle cell lipomas with atypia (mixed spindle cell/pleomorphic lipomas) without lipoblasts (three cases); (3) subcutaneous atypical well-differentiated fatty tumors (pure pleomorphic lipomas) without lipoblasts (nine cases); (4) subcutaneous atypical well-differentiated fatty tumors (pleomorphic lipomas) with lipoblasts (17 cases); (5) subcutaneous atypical fatty tumors with poorly differentiated or de-differentiated areas (three cases). Follow-up information was obtained in 25 cases (68%). The follow-up times were from three to 192 months (median 31). Five tumors (20%) recurred, two as the same and three as a higher histological category. Two were originally referred because of a recurrence. Four recurred once and one, initially a category 4 tumor, recurred twice as a category 5 tumor. Two category 1 and three category 4 tumors recurred. There were no recurrences in the other three groups. All recurrent tumors were located outside the cervico-dorsal areas. The sizes of two tumors that recurred were 2.8 and 3 cm and the time to first recurrence was from one to 85 months. Two recurrent tumors of high histological category were controlled by re-excision and either radiotherapy or combined chemotherapy and radiotherapy. This series suggests that atypical subcutaneous fatty tumors comprise a continuous and potentially transforming histological spectrum, which ranges from mildly atypical fibrolipomas through various mixed spindle cell and pleomorphic lipoma patterns to tumors indistinguishable from de-differentiated liposarcomas. Despite a sometimes alarming histological appearance, none in the present series metastasized.

Adult↗

PubMed2002

Continuous monitoring of the subcutaneous glucose level in freely moving normal and diabetic rats and in humans with type 1 diabetes.

Laboratory animals are extensively used in diabetic research. However, it is not known whether the glucose dynamics in laboratory animals are similar to the dynamics in humans. The aim of the present study is to see whether the Medtronic MiniMed continuous subcutaneous glucose monitoring system can be used to record fluctuations of the glucose level in freely moving normal and insulin-treated diabetic rats. The monitoring system was applied during 3 days to normal and diabetic hyperglycemic and hypoglycemic rats treated with insulin implants. Corresponding data from type 1 diabetic patients with poor glycemic control were selected retrospectively in order to note the similarities and differences. In normal rats the subcutaneous glucose level varied slightly (median = 111 mg/dL). In hyperglycemic rats the subcutaneous glucose values fluctuated markedly around a median of 226 mg/dL. The fluctuations formed a short-wave pattern with a low amplitude, superimposed on a long-wave pattern with a high amplitude. The subcutaneous glucose profile seen in type 1 diabetic patients (median = 180 mg/dL) was similar to that observed in hyperglycemic rats. In hypoglycemic rats, the subcutaneous glucose level fluctuated moderately around a median of 55 mg/dL. In these rats the fluctuations formed a short-wave pattern with low amplitude, without any obvious long-wave pattern. The subcutaneous glucose values conformed to corresponding blood glucose measurements. We conclude that the Medtronic MiniMed continuous glucose monitoring system can be used to record the subcutaneous glucose level over time in freely moving rats.

Adolescent↗

PubMed1982

Subcutaneous fat distribution in males and females from 1 to 39 years of age.

Subcutaneous fat thicknesses measured in two longitudinal studies, the Denver Growth Study and the Melbourne Growth Study, were examined to determine 1) if one site of subcutaneous fat measurement is more representative than another of the body's subcutaneous fat layer, 2) if some measurements of subcutaneous fat from specific body areas are more representative of the subcutaneous fat layer than others, and 3) if there are sex and age differences in intersite relationships. Data from the Denver Study include skinfold thicknesses from 10 sites measured serially at annual ages from 4 to 39 yr and radiographic fat thickness measured at five sites at annual ages from 1 to 18 yr. In the Melbourne Study, five skinfold thicknesses were measured serially in children from 2 to 15 yr of age. Relatively low intersite communalities during the prepubertal years suggest a tendency in each sex for considerable site-to-site variation during this period. However, immediately before puberty and throughout adolescence, high communalities indicate that the thickness of subcutaneous fat at any site is highly related to thickness at all other sites. After puberty and into the mid-20's, there is a reoccurrence of greater site-to-site variability. This higher degree of variation continues into early middle age only in women, implying that more changes occur in their subcutaneous fat, that differentially affect various parts of the body, than in men.

Adipose Tissue↗

PubMed1990

Dermatofibroma extending into the subcutaneous tissue. Differential diagnosis from dermatofibrosarcoma protuberans.

When dermatofibromas are composed predominantly of fibroblasts and extend into the subcutaneous tissue, it may be difficult to distinguish them from dermatofibrosarcoma protuberans. Because the patterns of extension of dermatofibroma have not been well characterized, we studied 185 cases of the fibrous variant of dermatofibroma with extension into the subcutaneous tissue and 40 cases of dermatofibrosarcoma protuberans. Dermatofibromas had two main patterns of extension into subcutaneous tissue. One pattern, seen in 133 of 185 cases (72%), consisted of irregular extension into the subcutaneous tissue in a vertical or radial fashion, predominantly along the septa, which appeared wedge-shaped. The other pattern, seen in 52 of 185 cases (28%), showed a smooth and well-demarcated deep margin that bulged into the subcutaneous tissue. Dermatofibrosarcoma protuberans also had two main patterns of extension into the subcutaneous tissue. In one pattern, seen in 12 of 40 cases (30%), slender spindle-shaped cells extended along septa and between fat cells in a classic honeycomb or lacelike pattern. The other pattern observed in 24 of 40 cases (60%) exhibited a distinct multilayered pattern in which the bundles of slender spindle-shaped cells showed a predominantly parallel orientation to the skin surface. In four cases (10%), a mixture of both patterns was present. We conclude that the patterns of extension of dermatofibroma into the subcutaneous tissue are different from the patterns of dermatofibrosarcoma protuberans.

Diagnosis, Differential↗

PubMed1996

Outcome of subcutaneous islet transplantation improved by polymer device.

Syngeneic transplantation of rat islets into subcutaneous tissue failed to cure streptozocin diabetes. The reason is unknown, but poor vascularization may play a role. We hypothesize that if a well-vascularized subcutaneous site could be created, islet grafts would do well. Four hundred freshly isolated mouse islets were transplanted syngeneically under the renal capsule or into the intraperitoneal cavity and compared with 800 islets in subcutaneous tissue of streptozocin-diabetic mice. Four weeks after transplantation, 14 of 14 under the renal capsule, 4 of 8 in the intraperitoneal site, and 0 of 7 in the subcutaneous tissue site achieved normoglycemia. To create vascularized organoids, we transplanted 800 mouse islets into polyvinyl alcohol (PVA) or polyglycolic acid (PGA) polymers in subcutaneous tissue of streptozocin-diabetic mice either immediately (four in PVA and six in PGA) or 7 days (four in PVA and four in PGA) after implantation. Four weeks after transplantation, the mean blood glucose level and body weight had no change with PVA. However, the mean body weight increased significantly with PGA and 3/10 became normoglycemic. When transplanting 400 islets with PGA polymers intraperitoneally, all animals (n=5) remained hyperglycemic 3 months later. In contrast, four of five recipients transplanted with 800 islets with PGA polymers subcutaneously became normoglycemic. The grafts from successful animals contained numerous revascularized islets containing a substantial amount of insulin. These preliminary results indicate that subcutaneous islet transplantation using PGA polymers can improve the metabolic status and, in some cases, even cure diabetes in streptozocin-diabetic mice.

Animals↗

PubMed2002

Reversal of diabetes in mice by xenotransplantation of a bioartificial pancreas in a prevascularized subcutaneous site.

BACKGROUND: The subcutaneous site has been regarded as a potential site for a bioartificial pancreas. Transplantation of islets, encapsulated by the development of diverse biocompatible materials and structural designs, can reverse hyperglycemia in diabetic recipients. METHODS: Approximately 750 Sprague-Dawley rat islets macroencapsulated in an agarose/poly (styrene sulfonic acid) mixed gel were implanted into a prevascularized subcutaneous site. The site was constructed by subcutaneous injection of basic fibroblast growth factor (bFGF)-impregnated gelatin microspheres in streptozotocin-induced C57BL/6 diabetic mice. Diabetic mice treated with bFGF-free gelatin microspheres and diabetic mice without any treatment undergoing the same subcutaneous transplantation were used as controls. After transplantation, non-fasting blood glucose, body weight, intraperitoneal glucose tolerance test, and histologic evaluations were processed. RESULTS: All the recipients undergoing the subcutaneous xenograft returned to normoglycemia within 1 week after transplantation. Eight of 10 recipients in the bFGF+ group maintained normoglycemia for a period of 38-101 days and gradually gained increase of body weight. Two of 10 recipients became hyperglycemic again when the grafts were respectively retrieved at days 31 and 63. Intraperitoneal glucose tolerance tests at month 1 and 2 revealed significant ameliorated glucose tolerance but a tendency to reduced glucose tolerance when compared respectively with those of the streptozotocin-induced diabetic mice and normal mice. Histologic examination revealed that islets within the retrieved grafts at days 31 and 63 were viable and intact; no fibrotic overgrowth was present around the surface of grafts. CONCLUSIONS: A successfully prevascularized subcutaneous site could be constructed by a tissue bioengineering approach. Xenotransplantation of the agarose/poly (styrene sulfonic acid) mixed gel-based bioartificial pancreas in the prevascularized subcutaneous site could reverse diabetes in mice.

Animals↗

PubMed2006

Rimming of adipocytes by neoplastic lymphocytes: a histopathologic feature not restricted to subcutaneous T-cell lymphoma.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare cytotoxic T-cell lymphoma of the skin presenting with histopathologic features simulating those of a lobular panniculitis. The presence of neoplastic T-lymphocytes forming a rim around the individual fat cells in the subcutaneous lobules, so-called "rimming" of adipocytes, is considered a characteristic morphologic feature of this type of cutaneous lymphoma. In this study we reviewed a series of 45 biopsy specimens of primary and secondary cutaneous B- and T-cell lymphomas and one of myeloid leukemia involving the subcutaneous tissues and showing rimming of adipocytes (subcutaneous panniculitis-like T-cell lymphoma: n = 16; mycosis fungoides, tumor stage: n = 3; aggressive epidermotropic CD8(+) T-cell lymphoma: n = 2; cutaneous gamma/delta T-cell lymphoma: n = 4; extranodal NK/T-cell lymphoma, nasal type: n = 4; cutaneous medium-large pleomorphic T-cell lymphoma, NOS: n = 5; CD4(+)/CD56(+) hematodermic neoplasm (blastic NK-cell lymphoma): n = 7; secondary cutaneous large B-cell lymphoma: n = 3; secondary cutaneous lymphoplasmacytic lymphoma: n = 1; specific cutaneous manifestations of acute myelogenous leukemia: n = 1). We could demonstrate that rimming of adipocytes by neoplastic cells can be recognized not only in subcutaneous panniculitis-like T-cell lymphoma, but also in several different entities of malignant lymphoma with skin involvement. Precise classification of cases with prominent involvement of the subcutaneous tissues can only be achieved upon precise correlation of clinicopathologic and phenotypic features. Rimming of adipocytes should not be considered specific of subcutaneous panniculitis-like T-cell lymphoma.

Adipocytes↗

PubMed1996

Subcutaneous blood flow in man during sleep with continuous epidural anaesthesia.

BACKGROUND: Subcutaneous blood flow increases during sleep and we evaluated if this increase is affected by epidural anaesthesia. METHODS: Lower leg subcutaneous blood flow was determined by 133Xenon clearance in ten subjects during continuous epidural anaesthesia at L2-L3 including eight hours of sleep, while the upper abdominal subcutaneous blood flow served as control. RESULTS: Epidural anaesthesia to the level of the umbilicus was followed by an increase in the lower leg subcutaneous blood flow from 3.4 (1.8-6.3) to 7.8 (3.6-16.9) ml min-1 100 g-1 (median and range; P < 0.001) and returned to 3.5 (2.4-7.6) ml min-1 100 g-1 after 88 (45-123) min. In contrast, until the period of sleep the upper abdominal region blood flow remained at 5.2 (3.2-6.4) ml min-1 100 g-1. During sleep, lower leg subcutaneous blood flow did not change significantly, but the upper abdominal flow increased to 6.2 (5.2-7.2) ml min-1 100 g-1 after 34 (29-70) min (P < 0.01), and it remained elevated for 125 (100-164) min. CONCLUSIONS: The results indicate that although epidural anaesthesia induced only a temporary increase in lower leg subcutaneous blood flow, it hindered the rise in subcutaneous blood flow normally manifest during early sleep.

Abdominal Muscles↗

PubMed2005

Merkel cell carcinoma arising from the subcutaneous fat of the arm with intact skin.

BACKGROUND: Merkel cell carcinoma is a rare malignant neuroendocrine neoplasm characteristically arising from the dermis of sunlight-exposed skin. It rarely arises outside the skin. OBJECTIVE: We present a patient with primary Merkel cell carcinoma arising from subcutaneous fat, with no involvement of the overlying skin. We describe the clinical manifestations and magnetic resonance imaging (MRI) findings. METHODS: We report a 63-year-old woman with a primary lesion of Merkel cell carcinoma that arose from the subcutaneous fat layer of the left arm. The lesion presented as a subcutaneous nodule with intact overlying skin. MRI showed that the nodular lesion was located entirely in the subcutaneous fat layer, with no involvement of the dermis. Peritumoral infiltration around the lesion and enlarged lymph nodes deep to the lesion were noted. The patient received wide excision of the lesion with dissection of the regional lymph nodes and adjuvant radiotherapy and chemotherapy. RESULTS: Histopathologic examination confirmed the diagnosis of Merkel cell carcinoma with local lymphatic metastasis, and the lesion was completely located in the subcutaneous fat, with no involvement of the dermis. These findings were well correlated with MRI findings. CONCLUSION: Primary Merkel cell carcinoma may arise from the subcutaneous fat and present as an entirely subcutaneous lesion with intact skin. MRI is helpful to evaluate the local extension of the lesion and regional lymphatic metastasis.

Arm↗

PubMed1991

Comparative efficacy of subcutaneous mesh and plate electrodes for nonthoracotomy canine defibrillation.

To determine the optimal configuration for the subcutaneous placement of electrodes for the performance of ventricular defibrillation without thoracotomy, internal defibrillation using four different subcutaneous electrodes was performed in 13 anesthetized dogs (7-12 Kg, mean +/- SD: 9.2 +/- 1.5 Kg). An electrode (7 cm2) was positioned transvenously in the superior vena cava with the following electrodes randomly implanted subcutaneously on the left chest: small mesh electrode (14 cm2), large mesh electrode (28 cm2), small titanium plate electrode (14 cm2), and large plate electrode (28 cm2). Ventricular fibrillation was induced by applying alternating current; a monophasic defibrillation wave was administered between the superior vena cava and the subcutaneous electrodes 10 seconds later. The energy level associated with a 50% successful defibrillation, as predicted by logistic regression analysis, was defined as the ED50. After the completion of the defibrillation protocol using the four subcutaneous electrodes, the small mesh electrode was sutured to the epicardium and the ED50 measurements were repeated. Energy ED50s were lower when the superior vena cava electrode was used as the cathode rather than as the anode. Of the subcutaneous electrodes, the large plate electrode showed the lowest energy ED50 (3.3 +/- 0.9 joules). The plate electrodes had lower energy ED50s than the mesh electrodes, and the large electrode had a lower energy ED50 than the small electrodes. Using the epicardium electrode, transient arrhythmias and ST elevation were observed following successful defibrillation; however, no arrhythmias or ST-T changes were observed following defibrillation using the subcutaneous electrodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1985

Evidence that the arterial baroreceptors influence muscle blood flow and not subcutaneous flow in man.

Studies in man indicate that skeletal muscle blood flow is modulated via high pressure baroreceptors located in the carotid body. However, whether subcutaneous blood flow is influenced in this way remains controversial. Therefore, the aim of the present study was to determine whether subcutaneous as well as skeletal muscle blood flow was influenced by direct carotid body stimulation; this was done by means of neck suction. Six young healthy males were investigated. Subcutaneous and skeletal muscle blood flow in the forearm was measured by the local 133Xe washout technique. Neck suction of -20 mmHg was applied through a tight helmet covering the head and neck. In the supine position heart rate increased about 10%, mean arterial pressure was unchanged, subcutaneous blood flow was unchanged, but skeletal muscle blood flow increased about 70%. Measurements were repeated during neck suction, -20 mmHg, and 45 degrees head-up tilt (which is known to decrease subcutaneous blood flow and skeletal muscle blood flow by increasing sympathetic vasoconstrictor activity). Heart rate increased by about 20%, mean arterial pressure was unchanged, subcutaneous blood flow was unchanged and skeletal muscle blood flow increased about 100%. These results indicate that skeletal muscle blood flow is modulated through carotid baroreceptors. Subcutaneous blood flow seems not to be influenced by high pressure baroreceptor modulation, although a vasoconstrictor response to head-up tilt was demonstrated in this as well as other recent studies.

Adult↗