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PubMed2002

Rhizobium etli mutant modulates carbon and nitrogen metabolism in Phaseolus vulgaris nodules.

The aim of this study was to evaluate the biochemical events in root nodules which lead to increased yield when bean is inoculated with a Rhizobium etli mutant (CFN037) having increased respiratory capacity. CFN037-inoculated plants had 22% more nitrogen (N) than did wild-type (CE3)-inoculated plants. Root nodule enzymes involved in nodule carbon and nitrogen assimilation as well as in ureides and amides synthesis were assessed in plants inoculated with CFN037 and the CE3. Our results show that the xylem ureides content was lower while that of amino acids was higher in CFN037- compared with CE3-inoculated plants. Supporting these results, enzymes involved in ureide synthesis were reduced while activity of aspartate aminotransferase, glutamate synthase, sucrose synthase, and glucose-6-P dehydrogenase were increased in CFN037-induced nodules. Glutamate synthase and phosphoenolpyruvate carboxylase transcripts were detected early in the development of nodules induced by CFN037 compared with CE3. However, plants inoculated with strain CE3-vhb, which express the Vitreoscilla sp. hemoglobin and also displays increased respiratory capacity, did not have altered ureide transport in N2-fixing plants. The data suggest that inoculation with special selected mutant strains of R. etli can modulate nodule N assimilation and N transport compounds.

Amino Acids↗
PubMed2002

In vitro rapid organization of rabbit meniscus fibrochondrocytes into chondro-like tissue structures.

We described the behaviour of 120 days rabbit knee-meniscus cells in monolayer culture. The cells were grown forming cellular aggregates resembling true cellular nodules. Three stages of development of these nodules could be observed: formation of the cellular nodules between days 1 and 3; nodular growth, with their maximal at day 5; and nodular regression beginning at day 8. Ultrastructural analysis of the extracellular matrix of these cellular nodules was assessed on days 3, 5 and 8. At the formation stage, we could observe striated collagen fibrils and small bundles of tubular microfibrils either interspersed with very low quantities of amorphous elastin, being morphologically identical to elaunin fibers, or without only trace of elastin, being morphologically identical to oxytalan fibers. By day 5, fibrillar elements with 100 nm periodic ladder-like collagen VI fibrillar aggregates could also be detected. At day 8, the striated collagen fibrils and oxytalan fibers could not be observed. During this same period, there was an increase of a dense matrix comprised of collagen VI and mature elastic fibers. Chondroitin/dermatan sulfate proteoglycans were synthesized and became essential for the arrangement of collagen type VI, since chondroitinase ABC treatment of the culture disrupted collagen VI assembly, associated with the large spaces near the cell surface. In addition, the cells lost their fusiform morphology and changed into rounded cells. The results show that primary cultures of rabbit meniscus fibrochondrocytes maintain their capacity to form chondro-like structures in vitro. The organization process was rapid and uniform throughout the entire culture presuming that the normal signal transduction pathways are maintained intact and that essential factors in some phases of tissue organization are present.

Animals↗
PubMed1982

Expression of fibronectin and laminin in the rat liver after partial hepatectomy, during carcinogenesis, and in transplantable hepatocellular carcinomas.

The distribution in the F344 rat liver of two extracellular matrix and basement membrane components, fibronectin and laminin, was studied by immunofluorescence. Fibronectin was found diffusely in normal liver lining the sinusoids and in connective tissue surrounding blood vessels and bile ducts; laminin was present predominantly in the basement membranes of blood vessels and bile ducts and was only inconsistently seen lining the sinusoids. After partial hepatectomy (PH), there was a transient decrease of fibronectin in the central and midzone sinusoidal hepatic areas. This decrease was most marked on day 3 after the PH. Carcinogens caused marked changes in the distribution of fibronectin. Large extracellular deposits of fibronectin were seen in areas of oval cell proliferation in livers of rats treated with N-2-fluorenylacetamide (2-FAA) while being fed a choline-deficient diet. In contrast, the nodules that developed in these livers were almost completely devoid of fibronectin staining. Neoplastic nodules produced in rats by cyclic feedings of 2-FAA r by injections of diethylnitrosamine also contained little or no fibronectin. Laminin staining did not change markedly during these treatments, but increased staining was seen associated with the newly formed ductlike structures and oval cells in liver of rats treated with carcinogens. Transplantable hepatomas varied in their fibronectin staining from fibronectin-negative hepatomas to ones with fibronectin staining within or around every tumor cell. Laminin was only found around the vascular structures within the tumors. The presence or absence of fibronectin in hepatomas did not show an obvious correlation to growth rate or metastatic potential of the tumors studied.

2-Acetylaminofluorene↗
PubMed1987

Current management of the patient with autonomously functioning nodular goiter.

Autonomously functioning thyroid nodules (AFTNs) are presumably independent of TSH for growth and function and appear "hot" on scintiscan because they selectively concentrate radionuclide to a greater extent than the remaining thyroid gland, which is controlled by the normal TH-TSH feedback mechanism. Such autonomously functioning tissue may occur in "patchy" areas, as a solitary nodule, or as multiple nodules (classic Plummer's disease), with the mass of hyperfunctioning tissue and the related secretion of thyroid hormones determining whether the patient is euthyroid or hyperthyroid. Important diagnostic tests include a 99mTc thyroid scan, T4 RIA, T3 uptake, FTI, TSH RIA, and occasionally T3 RIA ("T3 thyrotoxicosis"). Solitary autonomous nodules in adult patients characteristically progress slowly over many years, with toxicity rarely developing in nodules less than 2.5 cm in diameter and occurring primarily in nodules 3 cm or larger and in older patients. The decision to treat a solitary nodule depends upon the size and degree of function of the nodule and the patient's age. Surgery and radioactive iodine are effective therapies. Hyperfunctioning thyroid nodules in children and adolescents (under age 18) have a more rapidly progressive course than those in adults and should be treated by thyroid lobectomy at the time of diagnosis. Subtotal thyroidectomy is the preferred treatment for most patients with toxic multinodular goiter, because it achieves prompt control of the hyperthyroidism and removes the goiter. Radioiodine therapy and long-term antithyroid drug therapy are alternative forms of treatment for patients who are poor surgical risks or who develop recurrent hyperthyroidism following thyroid surgery.

Adenoma↗
PubMed2000

Subcutaneous nodules in Henoch-Schönlein purpura.

A 6.5-year-old boy with active Henoch-Schönlein purpura developed subcutaneous nodules (SCN), a vasculitic manifestation previously unreported in children with this disease. The authors suggest that pressure played a role in the pathogenesis of the SCN.

Child↗
PubMed1991

Cytophotometric DNA analysis of adenomatous hyperplasia in cirrhotic livers.

The possibility of adenomatous hyperplasia (AH) being a precursor lesion of hepatocellular carcinoma (HCC) in human cirrhotic livers was investigated. Feulgen DNA cytophotometry was used to measure the DNA content of the hepatocytes in 13 AH nodules obtained from six cirrhotic livers. DNA distribution patterns were classified into types I (diploid pattern), II (hyperploid pattern) and III (aneuploid pattern). According to the cellular and structural atypia, AH nodules were divided into ordinary type (2 nodules) and atypical type (11 nodules), 6 of the latter possessing foci of apparent HCC within them. Two ordinary AH nodules showed a type I DNA distribution pattern, similar to the surrounding regenerative nodules. A major part of the atypical AH nodules also showed type I. However, small foci showing moderate and structural atypia within these atypical AH nodules presented a type I pattern with more hyperploid cells and some aneuploid cells and also a type II histogram pattern with some aneuploid cells. Neoplastic foci, found within 5 atypical AH nodules, displayed various patterns (type I, II, III) as seen in well-developed HCC nodules. These data may imply that atypical AH nodules are precursor lesions of HCC, or are actually undergoing malignant transformation. It is apparent that at least some HCCs occurring in liver cirrhosis evolve through AH.

Adult↗
PubMed1999

Cutaneous mucinous nodules associated with proliferating synovitis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is occasionally associated with specific or non-specific cutaneous conditions. In this report, we describe unusual cutaneous nodules arising on the skin overlying the inflamed joints of two patients with RA. The nodules were histopathologically characterized by mucinous granulation tissue associated with neutrophilic infiltration and proliferation of starry-shaped mesenchymal cells. The affected joints of both cases showed synovitis with synovial tissue hyperplasia due to RA. Because hyaluronic mucin, which is the major component of synovial fluids, was deposited in the nodules, intradermal inoculation of synovial cells seemed to be responsible for the nodular development. The nodules of one patient spontaneously resolved in several months. We are unaware of any report describing similar cases. Such nodules should be included as a cutaneous complication of RA, distinct from neoplasias.

Aged↗
PubMedDate not supplied

Gamma probe-guided thoracoscopic surgery of small pulmonary nodules.

Video-assisted thoracic surgery (VATS) is an interesting and emerging procedure for the diagnosis and treatment of peripheral pulmonary nodules. We developed a new radioguided surgical technique for the detection during VATS of pulmonary nodules smaller than 2 cm, situated deep in the lung parenchyma and neither visible nor palpable with endoscopic instruments. The procedure is divided into two phases. Two hours before surgery 0.3 ml of a solution composed of 0.2 mL of 99mTc-labeled human serum albumin microspheres (5-10 MBq) and 0.1 mL of non-ionic contrast is injected into the lesion under CT guidance. Then the patient is submitted to VATS. During thoracoscopy a collimated probe of 11 mm diameter connected to a gamma ray detector is introduced via an 11.5 mm trocar and the pleural surface of the suspected area is scanned. A hot spot indicates the presence of the radiolabeled nodule and hence the area to be resected. We treated 39 patients with small pulmonary nodules (mean size, 8.3 mm; range, 4-19 mm). The patients were 27 men and 12 women (mean age, 60.8 years; range, 13-80 years). Nineteen patients had a history of synchronous or metachronous malignancy. In all cases the nodule was detected and resected and the resection margins were pathologically free of tumor. Histological examination showed 21 benign and 18 malignant lesions (7 metastases and 11 primary lung cancers). Nine patients with a frozen section-based histopathological diagnosis of lung cancer without functional contraindications underwent a completion lobectomy by open surgery in the same surgical session. In conclusion, the radiolocalization of small pulmonary nodules by gamma probe during VATS is a safe and easy procedure, with fewer complications and a lower failure rate than other localization techniques.

Adolescent↗
PubMed2005

Long-term prognosis of thyroid nodule cases compared with nodule-free controls in atomic bomb survivors.

CONTEXT: Radiation exposure is associated with development of thyroid nodules. The long-term risk of thyroid cancer development in irradiated people with thyroid nodules, however, has not been clarified. OBJECTIVE: The objective of this study was to assess the long-term risk of cancer development in irradiated individuals with thyroid nodules. DESIGN, SETTING, AND PARTICIPANTS: This prospective study comprised 2637 atomic bomb survivors (mean age, 59 yr; 1071 men and 1566 women) who participated in the baseline thyroid study of the Nagasaki Radiation Effects Research Foundation from 1984 through 1987. The participants were divided into three groups at baseline by ultrasound findings: 82 cases of solid thyroid nodules other than cancer, 121 cases of thyroid cysts, and 2434 thyroid nodule-free controls. Both the solid nodule and the cyst groups included postoperative cases. In the solid nodule group, 68 cases had ultrasound-detected solid nodules, including 31 cases diagnosed as benign by cytological or histological examination. They were followed for an average of 13.3 yr. MAIN OUTCOME MEASURE: Incident thyroid cancer was measured during an average 13.3-yr follow-up period. RESULTS: During the follow-up period, six thyroid cancer cases (7.3%) were found in the solid nodule group, seven cases in the controls (0.3%), and one case (0.8%) in the cyst group. In 31 cases with solid nodules diagnosed as benign, three cases (9.7%) developed thyroid cancer. The hazard ratio (HR) for cancer development was significantly high at 23.6 [95% confidence interval (CI), 7.6-72.8] in the solid nodule group (HR, 40.2; 95% CI, 9.4-173.0 in 31 people with solid nodules diagnosed as benign) but not in the cyst group (HR, 2.7; 95% CI, 0.3-22.2), after controlling for age and sex. Sex, age, TSH level, thyroglobulin level, radiation dose, nodule volume, and increase in nodule volume did not predict cancer development in the solid nodule group. CONCLUSIONS: Risk of thyroid cancer development is high in atomic bomb survivors with solid thyroid nodules, suggesting the need for careful observation of irradiated individuals with such nodules.

Aged↗
PubMed1998

Suppressive effect of the angiogenesis inhibitor TNP-470 on the development of carcinogen-induced hepatic nodules in rats.

Tumor metastasis can be prevented by inhibiting angiogenesis. In the present study, we have demonstrated that the angiogenesis inhibitor TNP-470 also suppresses the development of primary hepatic nodules. Hepatocarcinogenesis was performed by the feeding of 2-acetylaminofluorene to hepatectomized rats during 8-14 weeks of age. Predominantly arterial-to-portal circulation and sinusoidal capillarization were determined by the staining of nodules with arterially infused ink and immunostaining for factor VIII-related antigen, respectively. Intraperitoneal administration of 30 mg/kg b.w. of TNP-470 twice a week significantly reduced the number of hepatic nodules. Among the nodules, hyperplastic nodules stained with ink, atypical hyperplastic nodules and hepatocellular carcinoma, all of which possess structurally altered sinusoidal endothelial cells or capillary-type endothelial cells, were dramatically decreased in number. Suppression was observed equally in nodules of all sizes. TNP-470 was more effective when administered during 8-20 weeks than during 14-26 weeks. In contrast, ink-non-stained hyperplastic nodules, which have normal sinusoidal endothelial cells, were not affected at all. The present results indicate that TNP-470 suppresses the development of primary hepatic nodules whose microvessels are capillaries or transitional forms from sinusoids to capillaries.

2-Acetylaminofluorene↗
PubMed1997

Inhibition by piroxicam of oxidative DNA damage, liver cirrhosis and development of enzyme-altered nodules caused by a choline-deficient, L-amino acid-defined diet in rats.

Previously, we have reported that aspirin, a cyclooxygenase (COX) inhibitor, can prevent the fibrosis, cirrhosis and generation of oxidative DNA damage, and the associated development of glutathione-S-transferase placental form (GST-P)-positive preneoplastic liver nodules, caused by a choline-deficient, L-amino acid-defined (CDAA) diet in rats. In the present study, in order to elucidate the role of COX pathway in liver lesion-induction by a CDAA diet, the modulatory effects of other distinct chemical classes of COX inhibitors were examined. A long-acting example, piroxicam (PIRO) (at doses of 0.01, 0.02, 0.04 and 0.06%) and the short-acting ibuprofen (IBU) (at doses of 0.02, 0.04 and 0.06%) and indomethacin (IND) (at doses of 0.005 and 0.008%) were administered in the CDAA diet to male F344 rats, and animals were killed after 12 and 30 weeks. In another experiment, IND was given in drinking water at doses of 0.001, 0.002 and 0.004%. None of the inhibitors affected the development of fatty liver caused by a CDAA diet, but PIRO at doses higher than 0.04%, strongly inhibited the development of GST-P-positive and neoplastic nodules as well as fibrosis, cirrhosis and formation of 8-hydroxydeoxyguanosine (8-OHdG) adducts. IBU at the highest dose also exhibited similar but much less pronounced inhibitory effects. With IND, there was only a tendency for inhibition with no clear dose-dependence. The results together with our previous findings, indicate that relatively strong COX inhibitors, acting irreversibly like aspirin or for extended periods like PIRO, can prevent the endogenous hepatocarcinogenesis associated with a CDAA diet, although not the development of a fatty liver, suggesting that an augmented COX pathway might play key roles in the causation of liver lesions in this model.

8-Hydroxy-2'-Deoxyguanosine↗
PubMedDate not supplied

Leukemia cutis. Fine needle aspiration findings.

OBJECTIVE: To aspirate, for cytologic study, skin nodules from known cases of leukemia during full remission. STUDY DESIGN: The study group consisted of nine leukemia patients in full remission who developed skin nodules on the head, face, chest and upper extremities. RESULTS: The size of the nodules ranged between 1 and 3.5 cm. The nodules were aspirated with 21-gauge needle. Four were diagnosed as acute lymphoblastic leukemia, 1 as chronic lymphocytic leukemia, 1 as acute myeloblastic leukemia, 2 as acute monocytic leukemia and 1 as acute promyelocytic leukemia. Histologic sections were diagnosed as lymphoma-leukemia. The patients developed leukemia again three to four months after excision of the skin nodules. CONCLUSION: Fine needle aspiration cytology is useful in the diagnosis of leukemia cutis.

Adult↗
PubMed1993

Roles of plant homologs of Rab1p and Rab7p in the biogenesis of the peribacteroid membrane, a subcellular compartment formed de novo during root nodule symbiosis.

The peribacteroid membrane (PBM) in legume root nodules is derived from plasma membrane following endocytosis of Rhizobium by fusion of newly synthesized vesicles. We studied the roles of plant Rab1p and Rab7p homologs, the small GTP-binding proteins involved in vesicular transport, in the biogenesis of the PBM. Three cDNAs encoding legume homologs of mammalian Rab1p and Rab7p were isolated from soybean (sRab1p, sRab7p) and Vigna aconitifolia (vRab7p). sRab1p was confirmed to be a functional counterpart of yeast Ypt1p (Rab1p) by complementation of a yeast ypt1-1 mutant. Both srab1 and vrab7 genes are induced during nodulation with the level of vrab7 mRNA being 12 times higher than that in root meristem and leaves. This induction directly correlates with membrane proliferation in nodules. Antisense constructs of srab1 and vrab7, under a nodule-specific promoter (leghemoglobin, Lbc3), were made in a binary vector and transgenic nodules were developed on soybean hairy roots obtained through Agrobacterium rhizogenes-mediated transformation. Both antisense srab1 and vrab7 nodules were smaller in size and showed lower nitrogenase activity than controls. The antisense srab1 nodules showed lack of expansion of infected cells, fewer bacteroids per cell and their frequent release into vacuoles. In contrast, antisense vrab7 expressing nodules showed accumulation of late endosomal structure and multivesicular bodies in the perinuclear region. These data suggest that both Rab1p and Rab7p are essential for the development of the PBM compartment in effective symbiosis.

Amino Acid Sequence↗
PubMed1994

Clover development during spaceflight: a model system.

The development of legume root nodules was studied as a model system for the examination of gravitational effects on plant root development. In order to examine whether rhizobial association with clover roots can be achieved in microgravity, experiments were performed aboard the KC-135 parabolic aircraft and aboard the sounding rocket mission Consort 3. Binding of rhizobia to roots and the initial stages of root nodule development successfully occurred in microgravity. Seedling germination experiments were performed in the sliding block device, the Materials Dispersion Apparatus, aboard STS-37. When significant hydration of the seeds was achieved, normal rates of germination and seedling development were observed.

Cell Differentiation↗
PubMed1984

Mucocutaneous lentigines, cardiomucocutaneous myxomas, and multiple blue nevi: the "LAMB" syndrome.

We describe a 13-year-old girl with a cardiocutaneous syndrome characterized by an atrial myxoma, pigmented lesions of the skin and genital mucosa, and opalescent papules and dermal nodules of the skin and tongue. Her pigmented lesions included black macules of the face and vulva, brown macules of the lips and perioral skin, multiple blue nevi, and a congenital nevomelanocytic nevus. The black and brown macules of the face and vulva consisted of lentiginous proliferations of large, intensely dopa-reactive melanocytes. The opalescent papules and dermal nodules had histologic, ultrastructural, and histochemical characteristics of myxomas. During follow-up, the patient developed thyroid nodules, which were composed of mixed papillary and follicular hyperplasia. This case emphasizes the necessity of a cardiac evaluation for a potentially fatal (and surgically treatable) atrial myxoma in individuals with multiple melanocytic and myxomatous tumors of the skin and mucosa.

Adolescent↗
PubMedDate not supplied

Aspiration cytology of pulmonary small cell variant of poorly differentiated synovial sarcoma metastatic from the tongue: a case report.

BACKGROUND: Small cell variant ofpoorly differentiated synovial sarcoma (PDSS) is a great mimic of Ewing's sarcoma/primitive neuroectodermal tumor, with cytologic and immunohistochemical overlap. CASE: A 21-year-old male was admitted to our hospital because of a solitary pulmonary nodule that developed 22 months after resection of a tongue mass, small cell variant of PDSS. The nodule was biopsied via fluoroscopy-guided fine needle aspiration (FNA). At low power, the cytologic smears were highly cellular, consisting of a mixture of dispersed cells and loose or tight tissue fragments. The cells were characteristically uniform and monotonous, showing round to ovoid nuclei and scant cytoplasm. However, at high power, mild nuclear pleomorphism and frequent mitotic figures were noted. Blood vessels were often seen within the tumor cell aggregates. A diagnosis of metastatic sarcoma was rendered. Metastatectomy of the lung nodule was performed, and cytogenetic study showed t(X;18). CONCLUSION: A diagnosis of small cell variant of PDSS is difficult on routinely stained smears, but in the appropriate clinical setting, especially when a prior history of a primary tumor is available, a confident diagnosis can be established by FNA cytology. Immunohistochemistry and identification of SYT/SSX fusion transcript are useful for confirmation.

Adult↗
PubMed1990

Pericytes derived from the retinal microvasculature undergo calcification in vitro.

Pericytes isolated from the bovine retinal microvasculature retain characteristic features of their in vivo counterparts, such as the presence of glycogen deposits, long filamentous processes, prominent microfilament bundles and the ability to display two distinct and reversible phenotypes. Time-lapse video-microscopy demonstrated that pericytes tend to overlap and aggregate, even in sparse cultures. After reaching confluence, they form multilayered areas that retract away from each other, resulting in the formation of multicellular nodules. These nodules increase in size and cellularity by going through repeated 5- to 6-h cycles of anchoring, spreading, cell proliferation and retraction. Alkaline phosphatase was not detected in pericytes at subconfluent or confluent densities, but this enzyme was expressed in areas of high cell density, such as multilayers and nodules. Pericytes synthesise and deposit an extracellular matrix at all stages of their in vitro development, including nodule formation. The matrix within the nodules contains cross-striated collagen fibres and matrix vesicles. Needle-like crystals of hydroxyapatite appear to be deposited within the matrix, thus leading to massive calcification of the nodule. Calcification, as assessed by electron microscopy, histochemical staining and X-ray microprobe analysis, occurred on plastic and collagen substrate in the absence of disodium-beta-glycerophosphate. The addition of this compound at 5 or 10 mM or the use of a collagen substratum (rather than plastic), brought forward the process of nodule formation and calcification by 3-6 days. Our results suggest that retinal pericytes may differentiate in vitro along the osteogenic pathway.

Animals↗
PubMed2000

Self-examination of thyroid nodules.

The management of occult small thyroid nodules found by ultrasonography is sometimes problematic. Self-palpation may be utilized in the follow-up of these nodules. We developed a method of thyroid self-examination (TSE). We examined the size of the nodules palpable by this method by ultrasonography. In 78 patients examined, all 38 tumors more than 2 cm in size, whereas only one of 14 tumors less than or equal to 1 cm in size, were palpable. These results suggest the clinical usefulness of TSE in the follow-up of thyroid tumors, which are very common and slow-growing.

Adolescent↗