Effect of increasing concentrations of nonionic detergent Triton X-100 on solubilization and structure of rat liver and adipose plasma membranes

The extent of solubilization and the structure of rat liver and adipose plasma membranes after treatment with nonionic detergent Triton X-100 were studied. The concentration of Triton X-100 varied from 0.005 to 0.050% (0.26-2.6 mg/mg membrane protein). The excimerization of the pyrene fluorescent probe and the relative vibronic band intensities in the pyrene monomer fluorescence spectrum were measured to evaluate the membrane lipid bilayer fluidity and polarity. The data on the aqueous pyrene fluorescence in the presence of Triton X-100 showed that formation of micellar aggregates occurred at detergent concentrations of over 0.015%. This value is a crucial factor in the detergent action on the membrane structure: both intensive extraction of plasma membrane proteins and fluidization of the lipid bilayer were observed only at Triton X-100 concentration over 0.015%. However, Triton X-100 did not exert any action on the polarity of the membrane hydrophobic regions.

Unique subcellular distribution of five annexins in resting and insulin-stimulated rat adipose cells

Several lines of evidence suggest that annexins, a family of phospholipid-binding proteins, play a role in cellular trafficking. Five annexins (I, II, V, VI, VII) were detected in rat adipose cells. They were primarily associated with the plasma membrane in a calcium-dependent manner. None of them redistributed with insulin treatment of the cells, in contrast to the glucose transporter GLUT4, which moved from intracellular membranes to the plasma membrane. Although the actual function of annexins in adipose cells remains to be determined, our data indicate that insulin-stimulated GLUT4 trafficking does not rely on a change in subcellular location of any of the five annexins detected so far in these cells.

Compartment ablation analysis of the insulin-responsive glucose transporter (GLUT4) in 3T3-L1 adipocytes

The translocation of a unique facilitative glucose transporter isoform (GLUT4) from an intracellular site to the plasma membrane accounts for the large insulin-dependent increase in glucose transport observed in muscle and adipose tissue. The intracellular location of GLUT4 in the basal state and the pathway by which it reaches the cell surface upon insulin stimulation are unclear. Here, we have examined the colocalization of GLUT4 with the transferrin receptor, a protein which is known to recycle through the endosomal system. Using an anti-GLUT4 monoclonal antibody we immunoisolated a vesicular fraction from an intracellular membrane fraction of 3T3-L1 adipocytes that contained > 90% of the immunoreactive GLUT4 found in this fraction, but only 40% of the transferrin receptor (TfR). These results suggest only a limited degree of colocalization of these proteins. Using a technique to cross-link and render insoluble ("ablate') intracellular compartments containing the TfR by means of a transferrin-horseradish peroxidase conjugate (Tf-HRP), we further examined the relationship between the endosomal recycling pathway and the intracellular compartment containing GLUT4 in these cells. Incubation of non-stimulated cells with Tf-HRP for 3 h at 37 degrees C resulted in quantitative ablation of the intracellular TfR, GLUT1 and mannose-6-phosphate receptor and a shift in the density of Rab5-positive membranes. In contrast, only 40% of intracellular GLUT4 was ablated under the same conditions. Ablation was specific for the endosomal system as there was no significant ablation of either TGN38 or lgp120, which are markers for the trans Golgi reticulum and lysosomes respectively. Subcellular fractionation analysis revealed that most of the ablated pools of GLUT4 and TfR were found in the intracellular membrane fraction. The extent of ablation of GLUT4 from the intracellular fraction was unchanged in cells which were insulin-stimulated prior to ablation, whereas GLUT1 exhibited increased ablation in insulin-stimulated cells. Pretreatment of adipocytes with okadaic acid, an inhibitor of Type-I and -IIa phosphatases, increased GLUT4 ablation in the presence of insulin, consistent with okadaic acid increasing the internalization of GLUT4 from the plasma membrane under these conditions. Using a combination of subcellular fractionation, vesicle immunoadsorption and compartment ablation using the Tf-HRP conjugate we have been able to resolve overlapping but distinct intracellular distributions of the TfR and GLUT4 in adipocytes. At least three separate compartments were identified: TfR-positive/GLUT4-negative. TfR-negative/GLUT4-positive, and TfR-positive/GLUT4-positive, as defined by the relative abundance of these two markers. We propose that the TfR-negative/GLUT4-positive compartment, which contains approximately 60% of the intracellular GLUT4, represents a specialized intracellular compartment that is withdrawn from the endosomal system. The biosynthesis and characteristics of this compartment may be fundamental to the unique insulin regulation of GLUT4.

Lipomatous medulloblastoma in adults. A distinct clinicopathological entity

We report on three patients who presented with a cerebellar medulloblastoma at age 48, 53, and 59 years. Histopathology showed typical features of medulloblastoma, in one case with marked neuronal differentiation. In addition, all neoplasms contained focal accumulations of mature fat cells. Immunoreactivity of adipocytes for S-100 protein, neuron-specific enolase, synaptophysin, microtubule-associated protein-2, and glial fibrillary acidic protein and the lack of immunoreactivity to type IV collagen suggest lipomatous differentiation of neoplastic primitive neuroectodermal cells rather than an admixture of mesenchymal elements. Mitotic activity was low and the growth faction, as determined by the MIB-1 labeling index, was less than 5%. All patients are alive with a recurrence-free interval ranging from 3.5 to 12 years. These three patients and five similar previously reported cases all fit into the concept of the lipomatous medulloblastoma as a new clinicopathological entity characterized by (a) typical features of a cerebellar medulloblastoma with advanced neuronal differentiation, (b) areas of lipomatous differentiation, (c) low proliferative potential, (d) manifestation in adults (mean age, 50 years), and (e) apparent favorable clinical prognosis.

Chronic effects of somatotropin treatment on response of subcutaneous adipose tissue lipolysis to acutely acting factors in vivo and in vitro

The basis of the chronic lipolytic effect of somatotropin on adipose tissue was investigated in sheep. Lipolytic rate was assessed in subcutaneous adipose tissue both in vivo, by microdialysis, and in vitro. Somatotropin treatment resulted in a small increase in basal (unstimulated) lipolysis and also in the maximum lipolytic rate observed in the presence of catecholamines both in vivo and in vitro. There was a small increase in the number of beta-adrenergic receptors but no change in the amount of the two isoforms of the stimulatory GTP-binding protein, Gs. Treatment with somatotropin decreased the response to antilipolytic agents such as the adenosine analog N6-phenylisopropyladenosine and prostaglandin E1. There was, however, no change in the number of adenosine receptors or amounts of the inhibitory GTP-binding proteins (Gi-1 plus Gi-2). Somatotropin also decreased prostaglandin E2 production by subcutaneous adipose tissue in vivo. Somatotropin treatment thus alters lipolytic regulation in sheep and this is characterized by changes in a number of proteins involved in this process.

Tissue deposition rates in relation to muscle fibre and fat cell characteristics in lean female pigs (Sus scrofa) following treatment with porcine growth hormone (pGH)

Two experiments were conducted to examine the effect of porcine growth hormone (pGH) on performance, carcase composition, muscle and fat deposition rates, muscle fibre characteristics, and fat cell volume in pigs. In the first experiment, ten pairs of littermates were treated with vehicle (saline buffer) or 80 micrograms pGH per kg live weight per day for 42 days starting at 50 kg live weight. In the second experiment, twelve pairs of littermates were untreated or treated with 3 mg pGH per day from approximately 56 kg live weight to slaughter at approximately 103 kg live weight. All pigs were fed ad libitum. In Experiments 1 and 2, respectively, feed intake decreased (10 and 11%) and the feed/grain ratio improved (8 and 13%), while daily gain was unaltered. There was an increase in deposition rates of muscle (11 and 22%), skin (27 and 23%), and bone (15% in both), and a decrease in deposition rates of intermuscular (48 and 24%) and subcutaneous (82 and 50%) fat. This resulted in a change in carcase composition towards more muscle (5 and 9%), bone (6 and 4%), and skin (18 and 12%), and less intermuscular (30 and 16%) and subcutaneous fat (51 and 32%). The increased muscle mass was due to enhanced hypertrophy of all muscle fibre types, while pGH did not affect the frequency of the different muscle fibre types. The reduction in subcutaneous fat was reflected in a similar reduction in fat cell volume. In contrast to the majority of pigs used in pGH experiments, the genotype used in the present experiments did not respond with respect to daily gain following pGH treatment. Furthermore, the increase in muscle deposition was rather low compared to results reported in pigs of other genotypes. These data together with published data on the cross-sectional area of muscle fibres indicate that genotypes with relatively large muscle fibres are less responsive to pGH treatment than genotypes with relatively small muscle fibres.

The fasciitis-panniculitis syndromes. Clinical and pathologic features

The authors propose to encompass under the designation of "fasciitis-panniculitis syndromes" (FPS) a group of disorders characterized by induration of the skin due to chronic inflammation and fibrosis of the subcutaneous septa and muscular fascia. The prototype of the FPS is eosinophilic fasciitis. Thirty-two consecutive patients with FPS were cared for at the author's hospital during a 10-year period. The association of the FPS with other diseases, clinical presentations, histologic features, and response to treatment were analyzed. Idiopathic FPS, that is, eosinophilic fasciitis, was diagnosed in 14 patients. In the remaining 18 cases, the FPS were ascribed to vascular disorders (n = 6), infections (n = 6), and neoplastic disorders (n = 3), while trauma, insect bites, and Sweet syndrome antedated the FPS in 1 patient each. The lesions had a sleeve-like distribution in 20 patients, plaque-like distribution in 7, and a combined pattern in 5. Skin biopsies revealed lesions in the deep subcutaneous layers with the pathologic triad of septal and fascial fibrosis, chronic inflammatory infiltration, and small-vessel vasculopathy. Spontaneous improvement occurred in 4 cases. Following cimetidine monotherapy, complete remission was achieved in an additional 3 of 5 patients. The concept of the FPS serves to advance our understanding on several fronts: emphasizing the clinical and etiologic diversity; recognizing a stereotypic tissue reaction pattern; highlighting the panniculitis in addition to the fasciitic component; and describing a similar response to drug therapy in different clinical settings. Based on the results of the present series, cimetidine may be recommended as first-line treatment.

Pleomorphic adenoma of the bronchus

An example of pleomorphic adenoma of the bronchus is described in a 27 year old male student who was referred for evaluation of a coin lesion identified incidentally on chest x ray. The tumour exhibited the classic histological, immunohistochemical and ultrastructural features of this rare entity but, in addition, contained mature and immature adipose tissue in the stroma and showed transition, in its superficial portion, between ostensibly normal bronchial mucus glands and tumour tubules. Neither of these features has been commented upon previously.

Adipocyte morphology during hormone-induced lipid deposition and mobilization. An ultrastructural investigation in the perfused cardiac fat

The rat pericoronary adipose tissue was perfused in the presence of either the liposynthetic hormone insulin or the lipolytic hormone noradrenaline. Insulin perfusion associated with a) larger adipocyte mean sectional diameter in comparison with noradrenaline perfusion; b) glycogen deposition; c) appearance of small fat globules at discrete sites at the periphery of the main lipid drop. The two latter phenomena were apparently dose-dependent. Massive lipid deposition was induced by addition of triglycerides to the perfusion medium and this associated with appearance of prominent endoplasmic reticulum in the cytoplasm. In noradrenaline-perfused adipose tissue many small lipid droplets surrounded the central lipid deposit and the endoplasmic reticulum was in the form of both thin long, dashed cisternae sometime surrounding lipid droplets and grouped, anastomosing tubular cisternae. The present work shows that the perfused white adipose tissue of the heart is a suitable model to study, in situ, the morphological effects of hormones in adipocytes.

Beta-adrenergic responsiveness of adenylate cyclase in human adipocyte plasma membranes in obesity and after massive weight reduction

The aim of this study was to find out how beta-adrenergic responsiveness of adipocytes is altered in obesity and by weight loss and to investigate what mechanisms lead to potential alterations in responsiveness. Crude plasma membranes were prepared from adipocytes of massively obese and normal-weight individuals, as well as previously obese patients that had lost an average of 38% of their initial weight after bariatric surgery. Stimulation of adenylate cyclase by isoproterenol varied considerably in fat cell plasma membranes from different individuals. Crude fat cell plasma membranes from obese patients were less responsive to isoproterenol than those from normal-weight subjects, whereas those from postgastroplasty patients were hyperresponsive. The response was correlated negatively with cell size and positively with beta-adrenergic receptor density and with the ratio of beta-receptors and stimulatory G-proteins (Gs). There was no correlation with Gs content. However, differences in receptor density between small and large cells or normal-weight, obese, and post-bypass patients could not explain the observed differences in responsiveness to isoproterenol between the different groups.

Ultrastructure of the adipose tissue matrix in children with malnutrition

Bioptic fragments of adipose white tissue taken from trochanterian area from children of 2-22 months old were ultrastructurally investigated. Children were of both sexes, 5 normal and 22 with clinical diagnosis of malnutrition. There were studied many interadipocyte spaces signalling out in cases with malnutrition modifications of different components, some of them related with the degree of malnutrition. There were noted: disorganisation and disappearance of basal membranes of capillaries and glycolema; modifications of endothelial cells with lesions of the capillary wall and free degraded red blood cells; disorganization of the ground substance in small areas or sometimes extended to all matrix of the space; collagen fibres reduced in number and size, and in two cases the presence of collagen fibrils with severe lesions, realeasing an electrondense material, fibrinoid-like; matrix infiltration, in some cases with lipids. In only one interadipocyte space a synaptic button was noted in contact with capillary. In malnutrition lesions of cellular elements of the white adipose tissue the following were observed: adipocytes, fibroblasts, fibrocytes, endothelial cells, mast cells--which in their turn are responsible for modifications of macromolecular structures of the extracellular matrix--glycosaminoglycans, proteoglycans, components of which biosyntheses are cell-dependent.

Three-dimensional arrangement of collagen and elastin fibers in the human urinary bladder: a scanning electron microscopic study

To clarify the arrangements of collagen and elastin fibers of the urinary bladder, we examined 9 human (male, aged 42 to 72) urinary bladders by scanning electron microscopy with chemical digestion methods. The mucosal layer was divided into 3 portions according to the collagen arrangement: the superficial portion interwoven densely by collagen fibrils, the middle portion layered by flat bundles of collagen fibrils and the deep portion made of a loose network of twisted collagen bundles. In the muscular layer, the smooth muscle fascicles were firmly covered with collagen sheets, while each muscle cell in a fascicle was accommodated by a thin sheath of collagen fibrils. The serosal layer consists of wavy collagen bundles piled up in a sheet, which was intercalated by clusters of adipose cells. Elastic fibers were, on the other hand, sparse throughout the bladder wall, except for denser networks around the blood vessels and muscle fascicles and beneath the peritoneal mesothelium. The arrangements of these components were discussed in relation to the mechanical function and compliance of the urinary bladder.

An ultrastructural study of brown adipose tissue in pre-term human new-borns

The ultrastructure of brown adipose tissue (BAT), the thermogenic type of adipose tissue, was investigated in biopsies from 4 pre-term human new-borns delivered at 25-27 week's gestational age and compared with peri-renal brown fat from 2 adult patients with phaeochromocytoma (a condition of brown fat activation). The cell size of brown adipocytes was smaller in pre-term new-borns than in adult patients; adipocytes were almost exclusively multilocular, suggesting active thermogenesis. In 3 of the pre-term new-borns, brown adipocyte ultrastructure indicated a good to high degree of differentiation (in particular at the level of mitochondria) as compared with activated brown fat cells found in adult patients; in one pre-term infant the tissue morphology was obviously suggestive of an earlier, proliferative phase of development and the differentiation process of brown adipocytes could be traced in some detail. The results suggest that (a) brown adipose tissue may be fairly well-differentiated and thermogenetically active in pre-term human new-borns weighing about 750 g at birth; (b) brown adipocytes apparently develop from vessel-associated cells, the early signs of adipocyte differentiation being glycogen and lipid accumulation; (c) the ultrastructural morphology of mitochondria of mitochondria in well-differentiated BAT from pre-term infants can strictly resemble that found in active brown adipose tissue of adult phaeochromocytoma patients.

Histology and histomorphometric analysis of the normal and atrophic heel fat pad

Light and electron microscopy was used for a histologic examination of normal heel fat pads and atrophic heel fat pads from patients with peripheral neuropathies. Histomorphometric analysis revealed an average 30% smaller mean cell area and 16% smaller mean cell diameters in the atrophic pads compared with the normal heel fat pads. Septal walls in the atrophic fat pads were often fragmented and approximately 75% wider than normal. Perineural fibrosis was also found in the atrophic heel fat pads. The Verhoeff elastic staining technique was used to determine the relative percentage of collagen to elastic tissue within the septae. No significant differences were noted between the normal and atrophic heels. The ultrastructure of the adipocytes from the normal and atrophic heel pads was similar to those found in abdominal subcutaneous fat. Lipid droplets of variable size and density thin the center of the adipocyte were surrounded by a thin border of cytoplasm. The interphase between adipocytes contained fine collagen and elastic fibers.

Comparison of glucose-transporter-containing vesicles from rat fat and muscle tissues: evidence for a unique endosomal compartment

Insulin-sensitive tissues (fat and muscle) express a specific isoform of glucose-transporter protein, GLUT4, which normally resides in intracellular vesicular structures and is translocated to the cell surface in response to insulin. Here we provide a biochemical comparison of GLUT4-containing structures from fat and muscle cells. We demonstrate that, in spite of totally different protocols for cell homogenization and fractionation used for adipocytes as compared with skeletal-muscle tissue, GLUT4-containing vesicles from both sources have identical buoyant densities, sedimentation coefficients, and a very similar, if not identical, protein composition. The individual proteins first identified in GLUT4-containing vesicles from adipocytes (GTV3/SCAMPs proteins and aminopeptidase gp160) are also present in the analogous vesicles from muscle. Intracellular microsomes from rat adipocytes also contain GLUT1, a ubiquitously expressed glucose-transporter isoform. GLUT1 has not been detected in intracellular vesicular pool(s) from skeletal-muscle cells, probably because of its low abundance there. GLUT1 in adipocytes is excluded from GLUT4-containing vesicles, but is found in membrane structures which are indistinguishable from the former by all methods tested and demonstrate the same type of regulation by insulin. That is, the GLUT1- and GLUT4-containing vesicles have identical densities and sedimentation coefficients in sucrose gradients, and translocate to the cell surface in response to hormonal exposure. Also, we describe a simple procedure for the purification of native glucose-transporter vesicles from rat adipocytes. Overall, our data suggest the existence of a unique endosomal compartment in fat and muscle cells which is functionally and compositionally different from other microsomal vesicles and which is responsible for insulin-sensitive glucose transport in these tissues.

Correlation between the light scattering and the mitochondrial content of normal tissues and transplantable rodent tumors

The development of noninvasive optical studies necessitates an understanding of the biological parameters which affect light propagation in soft tissues. In the present report, we have measured the optical properties of various normal (i.e., perfused liver, brain, skeletal muscle, white adipose tissue) and neoplastic rodent tissues (i.e., glioma, hepatoma, mammary adenocarcinoma) by using time-resolved spectroscopy. The contribution of the hemoglobin (+ myoglobin in the case of muscle) to the total light absorption at 780 nm has been determined. This contribution varies from about 25% (brain, skeletal muscle) to about 100% (white adipose tissue, 13762A mammary adenocarcinoma, 9L glioma). These results are explained by different blood volume fractions in the tissues and by the existence at 780 nm of other chromophores, such as the mitochondrial cytochrome oxidase. Secondly, the dependence of the light scattering of the tissue on both the cell and the mitochondrial content has been analyzed. The results indicate that there is no correlation between the light scattering and the DNA content, measured as an indicator of the cell number in the tissue. The scattering coefficient is proportional to both the succinate dehydrogenase activity and the mitochondrial protein content of the tissue, which are indicators of the mitochondria content of the tissue when based upon estimates of tissue wet weight.

Intraleucocytic malaria pigment and prognosis in severe malaria

The quantity of malaria pigment liberated into the circulation at schizogony reflects the pathogenic sequestered parasite burden in Plasmodium falciparum malaria, and may therefore be a measure of disease severity. Among 300 consecutive adult patients with severe falciparum malaria, the 40 who died had significantly higher proportions of malaria pigment-containing neutrophils on admission (mean = 7.7%, standard deviation (SD) = 5.9%) and pigment-containing monocytes (mean = 8.6%, SD = 5.9%) than did survivors (mean 3.2%, SD = 4.1% and mean 4.8%, SD = 4.6%, respectively) (P < 0.0001). This proved a better indicator of prognosis than the peripheral parasite count. A count of peripheral neutrophils containing visible pigment > or = 5% predicted a fatal outcome with 73% sensitivity and 77% specificity (relative risk 6.2, 95% confidence interval (CI) 3.2-11.8) compared to 60% sensitivity and 57% specificity for parasitaemia > 100,000/microL (relative risk 1.8, 95% CI 1.0-3.3). The peripheral blood count of pigment-containing neutrophils in severe malaria is a rapid, simple, and practical prognostic test.

Tissue differences in the response of the pyruvate dehydrogenase complex to a glucose load during the development of obesity in gold-thioglucose-obese mice

The activity of pyruvate dehydrogenase (PDHC), a key enzyme complex in the oxidative disposal of glucose, was measured after an oral glucose load in the heart, liver, quadriceps muscle, white adipose tissue (WAT) and brown adipose tissue (BAT) of gold-thioglucose (GTG)-obese mice at different stages during the development of obesity and in age-matched controls. Significant responses to the glucose load were seen 30 min post-gavage in heart, WAT and BAT of control mice but no change was observed in quadriceps muscle. The increase in activity of the active form of PDHC (PDHCa) in response to glucose in heart was reduced 2 weeks after the induction of GTG-obesity with no response in 5 or 10 week obese mice. A 2-3-fold increase in the PDHCa response in both WAT and BAT of 2 week obese mice was absent in 5 and 10 week obese animals. Basal PDHCa activity in quadriceps muscle was increased in 2 week obese mice but subsequently returned to control levels as obesity progressed. The glucose load produced no change in the activity of PDHCa in quadriceps muscle of obese mice. These results demonstrate that changes in the capacity for oxidative glucose disposal in different tissues, as indicated by changes in PDHCa activity, may contribute to glucose-intolerance and insulin-resistance in GTG-obese mice and that the response of the PDHC to insulin during the development of obesity varies in different tissues.

Evidence for a second pathway in the action mechanism of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Significance of Ah-receptor mediated activation of protein kinase under cell-free conditions

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) when administered directly to a nuclear-free subcellular homogenate of guinea pig adipose tissue, caused a significant rise in protein kinase activities within 1-10 min. Such a rapid response was not expected, based on the classic transcriptional mechanism of action for TCDD, i.e. TCDD first binds with its cytosolic Ah-receptor, translocates into the nucleus, dimerizes with "arnt" (a nuclear transcription factor), and activates genes containing "xenobiotic-responsive element" (XRE). The above actions of TCDD on protein kinases were clearly blocked by two specific Ah-receptor blockers, even under cell- and nucleus-free conditions. TCDD-induced increases in protein phosphorylation occurred mainly in cytosolic preparations (i.e. 100,000 g supernatant) devoid of nucleus, microsomes and plasma membranes and were still observed in the presence of inhibitors of protein phosphatases. Furthermore, TCDD caused a rise in protein tyrosine kinase activity in a purified Ah-receptor preparation, as well as in an isolated heat shock protein 90 complex preparation containing the Ah-receptor. This activation took place in the presence of actinomycin D and cycloheximide, indicating a portion of TCDD's action that is unrelated to de novo protein synthesis in this process. We have also obtained evidence indicating that this action of TCDD triggers the protein kinase mediated growth factor signal transduction pathway, such as stimulation of mitogen activated protein kinase 2 and tyrosine kinase activity. These results clearly support the view that the basic action pathway for such a TCDD-induced activation of protein kinases is distinctly different from its conventional action pathway involving changes in gene transcription in the nucleus.

Ultrastructure and immunohistochemistry of the embryonic type of fat identified in the human infant breast

In this paper we describe the light and electron microscopic appearance of the embryonic type of fat in human infant breast, together with immunocytochemical findings. This fat tissue was composed of numerous capillaries surrounded by a mixed population of undifferentiated mesenchymal cells and preadipocytes at various stages of differentiation. The preadipocytes were characterised by a number of cytoplasmic processes, varying numbers of lipid droplets, and an envelope of electrondense material outside the cell membrane. Immunocytochemistry showed a characteristic distribution of collagen type IV adjacent to and vimentin and S100 protein within the preadipocytes. This is the first report of the ultrastructure of the human mammary embryonic type of fat. The possible role of the embryonic type of fat in the development and growth of the human breast is discussed.

Nuclear shape analysis for the assessment of local invasion and metastases in clinically localized prostate carcinoma

BACKGROUND

Nuclear shape analysis of histologic sections from radical prostatectomy specimens has retrospectively predicted outcome in patients with clinically localized prostate carcinoma. If outcome could be predicted preoperatively by nuclear shape analysis, patients might be selected better for definitive surgical therapy. Morphometric analysis of preoperative biopsies, however, has not correlated positively with values obtained from analysis of prostatectomy specimens.

METHODS

The nuclear shapes of histologic specimens of 20 organ-confined carcinomas, 10 periprostatic fat-invasive carcinomas, 10 seminal vesicle-invasive carcinomas, and 12 lymph node-metastatic carcinomas from 52 patients who had undergone radical prostatectomy for clinically localized disease were evaluated.

RESULTS

Nuclei from areas of extraprostatic invasion or regional lymph node metastases were less round than those from the corresponding intraprostatic portion of the tumor (nuclear roundness factor (mean +/- SD) PPF, 51.2 +/- 3.1 vs. 31.2 +/- 3.2; SV, 52.4 +/- 4.1 vs. 31.6 +/- 2.5; and LN, 57.3 +/- 3.1 vs. 36.4 +/- 1.8; paired Student's t tests, P < 0.001). Cells sampled from the periphery of organ-confined tumors had a greater nuclear roundness factor (49.1 +/- 1.5) than did those sampled from the center (34.5 +/- 2.0; P < 0.001) or randomly throughout the tumor (37.8 +/- 1.6; P < 0.001). Nuclear roundness factors for all extraprostatic tumor foci and for peripheral tumor cells in organ-confined disease were similar (analysis of variance, P > 0.05). The intraprostatic portions of randomly sampled primary tumors had similar nuclear roundness factors, regardless of pathologic stage (P > 0.05). Among organ-confined carcinomas, nuclear shape was unrelated to tumor volume.

CONCLUSIONS

Pathologic stage in clinically localized prostate carcinoma cannot be determined by the nuclear shape profiles of intraprostatic tumor cells. Thus, patients with a poor prognosis or high pathologic stage can be recognized only when samples for morphometric analysis include high proportions of nuclei from the extra-prostatic carcinoma and nuclei from the periphery of organ-confined carcinoma that may not be sampled routinely by prostate biopsy.

Relative quantitative analysis of glucagon receptor mRNA in rat tissues

Total RNA prepared from nine rat tissues were analyzed for their content in glucagon receptor mRNA by two independent hybridization approaches: (1) simple dot blot analysis using labelled oligodeoxynucleotide; (2) highly specific RNase protection assay using labelled antisense RNA. Hybridization signal was quantified by laser densitometric scanning of autoradiographies. Results were expressed for each method relative to the liver content (100%) for either a constant amount of total RNA or for a constant amount of beta-actin mRNA. We obtained similar relative values of glucagon receptor mRNA per constant amount of total RNA by the two hybridization methods: in liver (100 and 100), in kidney (38 and 34), and in heart (12 and 11). The glucagon receptor mRNA was overestimated by the less specific dot assays, in adrenal glands (21 versus 10) and in adipose tissues (24 versus 5). In the stomach, brain, duodenum and lung, the signal was equal to or below the reliable quantification limit. Reverse transcription and polymerase chain reaction (RT-PCR) of glucagon receptor mRNA with limited cycle number were performed using two sets of primers: the first set amplified a single band at the 3' coding end, and the second, 3-6 bands at the 5' coding end, revealing tissue-specific polymorphism. RT-PCR data confirmed the presence of glucagon receptor mRNA in liver, kidney, heart, adrenal glands and adipose tissue, and allowed the detection of a very low amount of glucagon receptor mRNA in the stomach, the duodenum and brain but not in the lung.(ABSTRACT TRUNCATED AT 250 WORDS)

[Structural and functional changes in plasma membranes of rat adipose tissue after chronic gamma-irradiation at a dose of 1 Gy]

The structural (microviscosity, lipid-protein interactions, lipid composition) and functional (5'-nucleotidase properties) status of rat adipose plasma membranes was studied 4, 10 and 30 days after prolonged gamma-irradiation at 1 Gy dose (period of exposure 94 days). The relative content of unsaturated fatty acids of the membrane phospholipids from irradiated rats was decreased during the period under study, whereas cholesterol/phospholipid molar ratio and pyrene excimerization parameter remained unchanged. Efficiency of the inductive-resonance energy transfer from the membrane tryptophenyls to pyrene was raised at 10 days postirradiation indicative on the lipid-protein alterations within membrane matrix, gamma-irradiation was characterized by the following features of 5'-nucleotidase; (1) two-fold increasing of Michaelis constant Km and (2) raising by 3-4 degrees C of the breakpoint on the enzyme Arrhenius plot. Scatchard parameters of 3H-AMP binding to the irradiated plasma membranes (measured by rapid filtration technique) were not different from the control ones.

Properties of phosphatidate phosphohydrolase in rat adipose tissue

Previously we have identified the presence of two different phosphatidate phosphohydrolase (PPH) activities in rat adipose tissue, based on Mg(2+)-dependency. In the present investigation, we have further characterized these isoenzymes, using both aqueous dispersed and membrane-bound phosphatidate as substrates and differentiated these activities on the basis of both Mg(2+)-dependency and N-ethylmaleimide (NEM)-sensitivity. These two distinguishing criteria gave identical estimates of PPH activities present in the different subcellular fractions. The microsomal and cytosol fractions contained mainly the Mg(2+)-dependent (NEM-sensitive) form, which was inhibited by various thiol reagents, was inactivated by heating at 55 degrees C for 20 min, and was decreased significantly within 2 h after intraperitoneal administration of cystamine (200 mg/kg). Such treatments had no effects on the Mg(2+)-independent (NEM-insensitive) form of PPH, which was mainly located in the plasma membranes, mitochondrial and microsomal fractions. Addition of Lipid A and guanosine 5'-[gamma-thio]triphosphate to the assay mixture had no effect on the PPH activities. The Mg(2+)-independent PPH form, which was thermostable in the intact subcellular fractions, became thermolabile when these fractions were disrupted in the presence of Triton X-100. The present studies demonstrate that: (1) the thermostability is not a satisfactory index to differentiate these isoenzymes; (2) the thiol/disulphide exchange may be involved in the regulation of Mg(2+)-dependent PPH activity; and (3) the PPH isoenzymes do not seem to be under G-protein control in adipose tissue, as reported previously in the mesangial cell line.

Forskolin induces the reorganization of extracellular matrix fibronectin and cytoarchitecture in 3T3-F442A adipocytes: its effect on fibronectin gene expression

We studied the effect of forskolin on fibronectin and actin gene expression in 3T3-F442A adipogenic cell line. The structural organizations of extracellular matrix fibronectin and actin cytoskeleton were investigated in parallel. Immunofluorescence experiments showed that preadipocytes treated for 48 h with 10 microM forskolin exhibited an intensified network of both actin and fibronectin when compared to control. A similar picture was obtained with adipocytes given long-term exposure to forskolin. As determined by Western analysis, fibronectin protein levels were increased by 50-75% over control, both in preadipocytes and adipocytes. A parallel increase of fibronectin mRNA content was observed in forskolin-treated cells. In contrast, forskolin treatment of preadipocytes and adipocytes did not elicit any change in the steady-state level of either actin mRNA or protein. Nuclear run-on experiments showed that forskolin increased the fibronectin gene transcription rate but left that of the actin gene in adipocytes unchanged. These findings suggest the reorganization of the actin network in forskolin-treated adipocytes to be a consequence of fibronectin-enhanced biosynthesis and reorganization.