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PubMed2005

ACTH 1-24 inhibits proliferation of adrenocortical tumors in vivo.

OBJECTIVES: Although several lines of evidence suggest that the overall effects of the ACTH receptor, melanocortin 2 receptor (MC2-R), mediated signal transduction on adrenocortical growth and tumorigenesis are anti-proliferative, activation of MC2-R induces mitogens like jun, fos, and myc and activates the MAPK pathway. In vivo, potential effects of endogenous ACTH on adrenal tumori-genesis can not be separated from effects of other POMC derived peptides. METHODS: Murine adrenocortical tumor cells that lack MC2-R expression (Y6(pcDNA)) and Y6 cells stablely transfected with MC2-R (Y6(MC2-R)) were generated. Presence of functional MC2-R was demonstrated by RT-PCR and Western blot using an antibody for phosphorylated CREB. As a syngenic tumor model, LaHeF1/J mice simultaneously received 10(7) Y6(MC2-R) and Y6(pcDNA) subcutaneously, giving rise to MC2-R positive and negative tumors within the same animal. Animals were treated for 3 weeks in groups of 12 according to the following schedule: group A, control animals receiving saline injection; group B, animals receiving 5.7 ng/injection of a slow release formula of ACTH 1-24 administered i.p. three times a week (aiming at a low physiologic dose); and group C, animals receiving 57 ng/injection of ACTH 1-24 (high physiological dose). RESULTS: Twenty days of ACTH 1-24 treatment did not significantly affect corticosterone levels, endogenous ACTH levels or adrenal and thymus weight compared with saline injection. However, ACTH 1-24 treatment of group B and C mice significantly reduced tumor weight in MC2-R positive tumors in a dose dependent manner (P = 0.03), while no significant difference in tumor mass was observed in MC2-R negative tumors. PCNA and TUNEL staining, together with morphological characterization, demonstrated that these in vivo effects were due to reduced proliferation, while apoptosis and cellular hypertrophy within the tumor remained unchanged. CONCLUSION: MC2-R expression is associated with a less aggressive adrenal tumor phenotype and anti-proliferative effects can be amplified through stimulation with physiological doses of ACTH.

Adrenal Cortex Neoplasms↗

PubMed1988

In-vitro and in-vivo responsiveness of the corpus luteum of the mare to gonadotrophin stimulation.

Dispersed horse luteal cells were used to evaluate the ability of horse LH, hCG and PMSG to stimulate progesterone secretion in vitro. Morphological characterization of these cells before gonadotrophin stimulation indicated the presence of two populations of cells based on cell diameters. In luteal cells incubated as suspended cells, horse LH and hCG stimulated (P less than or equal to 0.05) progesterone production at all levels of treatment. Stimulation of progesterone secretion by hCG was greater (P less than or equal to 0.05) than by horse LH over the range of concentrations utilized. When mares (N = 7) received an intramuscular injection of 1000 i.u. hCG on Days 3, 4 and 5 after the end of oestrus, there was an increase (P less than or equal to 0.05), in peripheral progesterone concentrations beginning on Day 7 and continuing until Day 14 compared with controls (N = 7). Peripheral progesterone concentrations continued to be elevated in hCG-treated mares for Days 15-30 after oestrus in those mares that conceived. Although treatment with hCG increased progesterone concentrations, it had no influence on anterior pituitary release of LH as measured by frequency and amplitude of LH discharge. We conclude that the mare corpus luteum is responsive to gonadotrophins in vitro and that exogenous hCG can enhance serum progesterone concentrations throughout the oestrous cycle and early pregnancy.

Animals↗

PubMed1996

Skeletal malformations caused by the Dh (Dominant hemimelia) gene in mice.

Morphological characterization of the skeletal malformations caused by the Dh gene was carried out. Skeletal preparations from newborn mice of Dh/Dh, Dh/+ and +/+ genotypes, and adult Dh/+ mice were examined. The Dh gene induced skeletal deformities at the axial regions from the thorax to the tail. Attachment of the ribs to the sternum was sometimes irregular, and normal segmentation of the sternum was also disrupted. Abnormal fusion of the ventral part of the rib was observed in some cases. Lumbar vertebrae were fewer in number and abnormal in shape. Although it was rare, a curled tail was also observed due to distortion of the caudal vertebrae.

Abnormalities, Multiple↗

PubMed2004

[Thyroid nodular disease].

The thyroid gland is fairly homogeneous but nodules are frequent. Nodules greater than 1.0 cm are usually palpable, but non-palpable nodules, smaller than 1.0 cm are far more frequent. Thyroid nodular disease, the etiology of which is multifactorial, encompasses lesions, from the small incidentaloma to large multinodular intrathoracic goiter. The main diagnostic issues are related to the functional and morphological characterization using TSH measurements and image methods. Fine needle aspiration biopsy is the method of choice to rule out malignancy, the incidence of which is similar in single or multinodular goiter (MNG). MNG treatment can be surgical or radioactive iodine (131I) could be indicated if the 131I uptake is adequate. It is likely that the use of recombinant human TSH (rhTSH) will strongly change the application of 131I in MNG treatment. The benign single thyroid nodule, "cold" or "hot" at scintigraphy, can be treated with percutaneous ethanol injection. The "hot" nodule can also be treated by surgery or 131I.

Humans↗

PubMed1998

Schistosoma mansoni Sambon, 1907: morphometric differences between adult worms from sympatric rodent and human isolates.

A computer software for image analysis (IMAGE PRO PLUS, MEDIA CYBERNETICS) was utilized in male and females adult worms, aiming the morphological characterization of Schistosoma mansoni samples isolated from a slyvatic rodent, Nectomys squamipes, and humans in Sumidouro, Rio de Janeiro, Brazil and recovered from Mus musculus C3H/He. The following characters for males's testicular lobes were analyzed: number, area, density, larger and smaller diameter, longer and shorter axis and perimeter and extension; for females: area, longer and shorter axis, larger and smaller diameter and perimeter of the eggs and spine; oral and ventral suckers area and distance between them in both sex were determined. By the analysis of variance (one way ANOVA) significant differences (p < 0.05) were observed in all studied characters, except for the density of testicular lobes. Significant differences (p < 0.05) were detected for all characters in the female worms. Data ratify that sympatric isolates present phenotypic differences and the adult female characters are useful for the proper identification of S. mansoni isolates.

Analysis of Variance↗

PubMed2003

Deformations of the midfacial complex in twins with orofacial clefts.

OBJECTIVE: To investigate the craniofacial morphology in twins with cleft lip and/or palate (OFC) and localize differences, compared with noncleft (NC) twins. DESIGN: Retrospective study. SETTING: School of Dentistry, University of Michigan. SAMPLE: Posteroanterior cephalographs of 32 pairs of dizygotic, concordant, like-sexed twins. The NC group consisted of 20 pairs of noncleft twins. The cleft twin (CT) group consisted of 12 pairs of concordant twins (both exhibited OFC). MAIN OUTCOME MEASURES: Changes in linear distances, differences in form difference matrices, and visualization of deformations of thin-plate spline (TPS) transformation grids. RESULTS: Linear analysis indicated significant reductions in interorbital distance ( approximately 12%; p <.01) and reduced maxillary heights ( approximately 27%; p <.001) in CTs. Euclidean distance matrix analysis strongly supported these findings, confirmed that the form matrices were significantly different (p <.05), and indicated relative decreases in internasal width ( approximately 12%) and maxillary base width ( approximately 10%). The TPS analysis produced a transformation grid that showed superoinferior compression, suggesting that OFC is associated with a downward displacement of the nasomaxillary complex as well as distortion in the region of the maxillary base. CONCLUSIONS: Twins with orofacial clefts differ from their unaffected counterparts by a midfacial skeletal morphology characterized by decreases in interorbital and internasal widths and relatively shorter maxillary basal heights and widths. Although most of these differences appear to be due to compression and regionalized deformation, the resultant inferior displacement of the medial region of the midface concomitant with horizontal widening in the presumptive palatal region may be a development model associated with OFC.

Cephalometry↗

PubMed2002

Stictodora lari (Digenea: Heterophyidae): the discovery of the first human infections.

Stictodora lari Yamaguti, 1939 (Digenea: Heterophyidae) was originally reported as an avian intestinal parasite and is here reported in humans. The patients were adults, aged 46-69 (2 men and 4 women), who resided in coastal villages in Sachon-gun, Kyongsangnam-do, or Shinan-gun, Chollanam-do. in the Republic of Korea. The worms were recovered after praziquantel treatment and purgation with magnesium salts. A total of 15 S. lari specimens (1-10 per individual) was collected, together with 5 other species of intestinal flukes. The flukes were morphologically characterized by a small body size (0.70-0.86 mm long and 0.27-0.36 mm wide), a ventrogenital sac, and a gonotyl armed with 70-80 spines in the form of a comma or reversed comma lying along their lateral margin. The patients had eaten the raw flesh of mullets and gobies that had been caught in an estuary near their villages. To the best of our knowledge, this is the first record of a human S. lari infection.

Aged↗

PubMed1994

Neuropeptide Y-immunoreactive neurons in the retina of two Australian lizards.

Wholemounts and sectioned retina from adults of two lizard species, Pogona vitticeps and Varanus gouldii, were studied by immunohistochemistry for neuropeptide Y (NPY)-like immunoreactivity. In both species the morphology of two classes of amacrine cells (types A and B) were described. Cell somata were located mostly in the inner nuclear layer (INL) but were occasionally displaced into the ganglion cell layer (GCL). In the Pogona retina, type A cells had large somata and dendritic arbor that branched in sublamina (S) 1 and 2/3 of the inner plexiform layer (IPL). Type B amacrine cells had smaller somata and dendritic arbor branching mostly in S5 of the IPL. In the Varanus retina, the levels of dendritic branching of types A and B amacrine cells in the IPL were similar to those in Pogona although branching in the middle of the IPL occurred at S3. NPY-immunoreactive cells with small somata and narrow to medium sized dendritic fields were predominant. Unclassified cells also displayed NPY-like immunoreactivity; however, their dendritic morphology could not be determined due to the faint and inconsistent staining. In transverse retinal sections three bands of NPY-like immunoreactivity were evident in the IPL of both species, to which the unclassified cells also contributed. In both species type A cells were most numerous. Total NPY-immunoreactive cells were estimated to be 8,600 in Pogona and 32,860 in Varanus. In both species types A and B cells were non-uniformly distributed across the retina. The most apparent non-uniformity in distribution was observed in type A cells in Varanus. Peak cell density was found across the horizontal meridian of the retina from where cell density decreased towards the dorsal and ventral retinal margins. The results of this study provide evidence for the presence of NPY-immunoreactive amacrine cells in the lizard retina of which two types were morphologically characterized. Cross-species comparisons were also made among NPY-immunoreactive amacrine cells, and their possible function/s discussed.

Animals↗

PubMed2001

Professor Toshio Ito: a clairvoyant in pericyte biology.

Ito cells are liver-specific pericytes which were first described as Fett Speicherung Zellen, the fat-storing cells encircling outside sinusoidal endothelial cells, in 1951 by the late professor Toshio Ito. His pioneering approaches for morphological characterization of the cells stimulate investigators to further examine their functional roles in liver homeostasis: a body of evidence has been accumulated in recent years showing that the cells play a crucial role in storage and delivery of vitamin A, regulation of sinusoidal tone and local blood supply, and tissue repair and fibrosis. It is now widely accepted that microvascular pericytes including Ito cells serve as a key player that controls angiogenesis. Furthermore, recent studies support a concept that Ito cells constitutes a bridging apparatus mediating bidirectional metabolic interactions between sinusoids and hepatocytes, utilizing prostanoids and/or gaseous mediators such as nitric oxide and carbon monoxide as signaling molecules. This article reviews researches on this liver-specific pericyte and its leading roles in recent development of pericyte biology.

Animals↗

PubMed2006

Toxic epidermal necrolysis and Stevens Johnson syndrome: our current understanding.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN, Lyell's syndrome) are now considered to be distinct clinical entities within a spectrum of adverse cutaneous drug reactions of increasing severity based on their surface of skin detachment. Within this spectrum, SJS which can be considered as a minor form of TEN is characterized by less than 10% body surface area of skin detachment, and an average reported mortality of 1-5%, whereas TEN is characterized by more than 30% skin detachment, and an average reported mortality 25-35%. Both SJS and TEN are characterized morphologically by the rapid onset of keratinocyte cell death by apoptosis, a process that results in the separation of the epidermis from the dermis. Recent evidence is supportive of a role for inflammatory cytokines and the death receptor Fas and its ligand FasL in the pathogenesis of keratinocyte apoptosis during TEN. This Fas-mediated keratinocyte apoptosis that is the last step culminating in epidermal detachment in TEN can be inhibited in vitro by antagonistic monoclonal antibodies to Fas, and by intravenous immunoglobulins (IVIG) which have been shown to contain natural anti-Fas antibodies. Consequently, over the last few years, numerous case reports and 9 non-controlled clinical studies containing 10 or more patients have analyzed the therapeutic effect of IVIG in TEN. Taken together, although each study has its potential biases, 7 of 9 such studies point towards a benefit of IVIG used at doses greater than 2 g/kg on the mortality associated with TEN. These studies should serve as the basis for designing an appropriate prospective trial or for conducting a metaanalysis in the near future, in order to determine the therapeutic efficacy of IVIG in TEN.

Drug Eruptions↗

PubMed1995

Evolution of beta-cell dysfunction in the male Zucker diabetic fatty rat.

The molecular basis for the beta-cell dysfunction that characterizes non-insulin-dependent diabetes mellitus (NIDDM) is unknown. The Zucker diabetic fatty (ZDF) male rat is a rodent model of NIDDM with a predictable progression from the prediabetic to the diabetic state. We are using this model to study beta-cell function during the development of diabetes with the goal of identifying genes that play a key role in regulating insulin secretion and, thus, may be potential targets for therapeutic intervention aimed at preserving or improving beta-cell function. As a first step, we have characterized morphology, insulin secretion, and pattern of gene expression in islets from prediabetic and diabetic ZDF rats. The development of diabetes was associated with changes in islet morphology, and the islets of diabetic animals were markedly hypertrophic with multiple irregular projections into the surrounding exocrine pancreas. In addition, there were multiple defects in the normal pattern of insulin secretion. The islets of prediabetic ZDF rats secreted significantly more insulin at each glucose concentration tested and showed a leftward shift in the dose-response curve relating glucose concentration and insulin secretion. Islets of prediabetic animals also demonstrated defects in the normal oscillatory pattern of insulin secretion, indicating the presence of impairment of the normal feedback control between glucose and insulin secretion. The islets from diabetic animals showed further impairment in the ability to respond to a glucose stimulus. Changes in gene expression were also evident in islets from prediabetic and diabetic ZDF rats compared with age-matched control animals. In prediabetic animals, there was no change in insulin mRNA levels. However, there was a significant 30-70% reduction in the levels of a large number of other islet mRNAs including glucokinase, mitochondrial glycerol-3-phosphate dehydrogenase, voltage-dependent Ca2+ and K+ channels, Ca(2+)-ATPase, and transcription factor Islet-1 mRNAs. In addition, there was a 40-50% increase in the levels of glucose-6-phosphatase and 12-lipoxygenase mRNAs. There were further changes in gene expression in the islets from diabetic ZDF rats, including a decrease in insulin mRNA levels that was associated with reduced islet insulin levels. Our results indicate that multiple defects in beta-cell function can be detected in islets of prediabetic animals well before the development of hyperglycemia and suggest that changes in the normal pattern of gene expression contribute to the development of beta-cell dysfunction.

Animals↗

PubMed2006

In vitro propagation of spermatogonial stem cells from KM mice.

Spermatogonial stem cells (SSCs) are a unique type of stem cells in that they transmit genetic information to the next generation by producing sperms. Studies of SSC proliferation and differentiation have been hampered by the inability of reconstructing these processes in vitro, particularly in a serum-free culture system. Several groups have reported the long term culture of SSCs during which SSCs self-renew and restore spermatogenesis when transplanted back to recipient testes. However, different protocols and mice with particular genetic background have been used by different laboratories, and the techniques have not been adopted widely. In the present study, we first established a SSC isolation and culture system composed of differential adherence selection of SSCs, serum-free medium and mouse embryonic fibroblast (MEF) feeder cells. SSCs from KM pups could be cultured on MEF feeders in StemPro-34 SFM Medium supplemented with glial cell line-derived neurotrophic factor (GDNF), soluble GDNF family receptor alpha-1 (GFRa1) and basic fibroblast growth factor (bFGF) for 1 month. These SSCs were characterized morphologically and by examining the expression of marker genes. Expression of Oct4 and Sox2, which are crucial factors in embryonic stem cell (ESC) self-renewal, were detected in our cultured SSCs, suggesting that SSCs may share with ESCs some common mechanisms in self-renewal regulation. We also found that LIF had no effect on the proliferation of cultured SSCs derived from KM mice.

Animals↗

PubMed1993

Culture of human endometrial cells: a new simple technique to completely separate epithelial glands.

In vitro studies on dispersed human endometrial cells are still difficult to perform as the techniques employed do not allow an optimal separation of the cells. In particular, epithelial glands tend to maintain their tubular structure even after enzymatic dispersion. This could be a disadvantage when monolayers of single well dispersed cells are needed. In this paper we describe a new technique to establish monolayer cultures of isolated endometrial stromal and epithelial cell populations. After a first collagenase digestion, stromal and epithelial cells were separated by differential sedimentation at unity gravity. The epithelial glands obtained were further dispersed in single cells using a short incubation with low amount of trypsin. Morphologic characterization was performed using immunohistochemistry for vimentin and cytokeratins. Compared to previous described methods, this procedure is shorter and could better preserve cell surface structures. Thus, it could be successfully employed for in vitro studies of human endometrial pathophysiology.

Cell Separation↗

PubMed1976

Experimental autoimmune glomerulonephritis in the rat. II. A histopathological and fine structural study.

Human glomerular basement membrane (GBM) emulsified in Freund's complete adjuvant was injected into 16 Holtzman rats. Eleven (69%) of them subsequently developed glomerulonephritis. This disease was characterized by glomerular changes which included focal lobular hypercellularity due to localized hyperplasia of intracapillary (mesangial or endothelial) cells which often obstructed glomerular capillaries. Later, affected lobules showed necrosis of intracapillary cells, and capillary lumina were filled with homogeneous eosinophilic material. An immunoperoxidase technique revealed autologous anti-GBM antibody in all 3 layers of the GBM and in some regions it was present in greater amount in the lamina rara interna and externa than in the lamina densa. Experimental auto-immune glomerulonephritis in the rat is thus characterized morphologically by a focal proliferative glomerulonephritis which proceeds to focal glumerulosclerosis.

Animals↗

PubMed1991

Examination of neurons in wild type and mutants of Caenorhabditis elegans using antibodies to horseradish peroxidase.

Antibodies to horseradish peroxidase (HRP) recognize 27 of 302 neurons and several non-neuronal cells in adult hermaphrodites of the soil nematode Caenorhabditis elegans and can be used to label these cells for cytological analysis in whole animals. The antibodies bind to the anterior members, but not to the posterior members of a set of mechanosensory neurons in wild type animals. Binding to one of the posterior mechanosensory neurons (PVM) occurs when this neuron migrates to an abnormal anterior position in mab-5 mutant animals, suggesting that expression of the epitope recognized by these antibodies is position dependent or that mab-5 mutations transform PVM into AVM intrinsically. The antibodies were used to characterize morphologies of two pairs of lumbar neurons (PHC and PVN) in uncoordinated mutants representing 95 unc genes. PHC and PVN morphologies were normal in most of the unc mutants examined, however, in mutants of 9 unc genes (unc-6, unc-13, unc-33, unc-44, unc-51, unc-61, unc-71, unc-73, and unc-98), misdirected PHC and/or PVN processes were observed at a high frequency. The morphologies of 2 other lumbar neurons, PHA and PHB, were determined previously in these mutants (Hedgecock et al., 1985). Mutations in most, but not all of these 9 unc genes affect the growth of the embryonic lumbar neurons PHA and PHB differently than they affect the growth of the postembryonic lumbar neurons PHC and PVN, indicating that these neurons require different, but overlapping sets of genes for different stages of normal growth and guidance.

Alleles↗

PubMed1983

Reaction of rat lungs to inhaled chrysotile asbestos following acute and subchronic exposures.

Inhalation of asbestos fibers can cause fibrotic and neoplastic diseases in the lung. The early in vivo interactions between fibers and lung tissue that initiate these diseases have received little study. Male and female Fischer 344 rats were placed in inhalation chambers and exposed to 9.06 +/- 1.83 mg/m3 (average respirable mass) of chrysotile asbestos for 1 hr, 1 day, 7 hr/day for 5 days, or 5 days/week for 3 months. Qualitative examination of the tissue showed that, after 1 day, fibers were found not only in the alveolar macrophages, but also in the epithelium and interstitium of the alveolar region. After 3 months, numerous fibers were present in the epithelium and interstitium. Morphometric analysis of this tissue showed that these compartments were also the most significantly changed as a result of asbestos exposure. The majority of epithelial changes were attributable to a 57% increase in the number of type II cells and a 90% increase in their average cell volume. The interstitial cell population increased 58% with a 40% increase in the average cell volume. There was no significant increase in the volume of noncellular interstitium. A morphologic characterization of the interstitial cells showed that interstitial macrophages accounted for almost the entire increase in this population and that 88% of the fiber-containing cells were macrophages. Several interstitial macrophages contained membrane-bound inclusions which were shown by x-ray energy spectrometry to be microcalcifications. They were composed of rings of calcium phosphate granules around asbestos fibers. These microcalcifications may indicate sublethal cell injury caused by the presence of asbestos fibers in the cell cytoplasm. Fibers which enter but do not kil alveolar cells may be an essential component for the pathogenesis of lung disease caused by asbestos inhalation.

Animals↗

PubMedDate not supplied

Pancreatic endocrine tumor with signet ring cell features: a case report with novel ultrastructural observations.

The case of a malignant pancreatic endocrine neoplasm with an unusual signet ring cell appearance is reported. The tumor was resected from a 30-year-old man with a 4.0-cm tumor in the body of the pancreas diagnosed by computerized tomographic (CT) scan. The resected tumor had a unique morphology characterized by numerous mucin-negative, signet ring cells, which were argyrophilic and immunoreactive for cytokeratin (CAM 5.2), chromogranin, synaptophysin, neuron specific enolase, and gastrin. Dense-core neurosecretory-type granules and numerous cytoplasmic lamellar inclusions were identified by electron microscopy. These inclusion bodies consisted of multilayered concentric osmiophilic lamellae (myelin figures), which most likely represent an abnormal accumulation of degenerating organelles. Two years later, the patient developed an abdominal recurrence of the tumor, confirming its malignant behavior. This case expands the spectrum of pancreatic endocrine tumors to include an aggressive signet ring cell tumor with a novel ultrastructural basis.

Abdominal Neoplasms↗

PubMedDate not supplied

Simplex lattice design for the optimization of the microencapsulation of a water soluble drug using poly(lactic acid) and poly(lactide co-glycolide) copolymer.

An emulsion solvent evaporation technique was applied to prepare microspheres of nicotinic acid as a water soluble vitamin. Poly(lactic acid) of two molecular weights, 2000 and 100,000 and poly(lactide-co-glycolide) (50:50) of molecular weight 18,000 were used. A simplex lattice design with the aid of a computer program was applied to study the effect of the previously mentioned polymers on different characteristics of the prepared microcapsules. The studied characteristics included the yield, the percentage drug loading and the particle size of microcapsules. Microcapsules were examined by light microscope for particle size determination and by electron scanning microscope for surface morphology characterization. The release pattern of the drug from the microcapsules was evaluated on the basis of the burst effect, the rate of release and the extent of release after 24 h. A model equation was developed to be the best representation of the relationship between the above polymers and the measured characteristics. The goodness of fit of the developed equations was checked, both statistically and experimentally. The release of the drug from microcapsules mainly followed the Higuchi diffusion model. Polylactic acid of a molecular weight 100,000 had the most pronounced delaying effect on the release rate of the drug. However, polylactic acid of a molecular weight 2,000 showed the highest improvement effect on the yield and the drug loading characteristics of the microcapsules. Poly(lactide-co-glycolide) copolymer exhibited the lowest burst effect and the most steady drug release pattern.

Drug Compounding↗