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PubMed1995

Acquired coccygeal nodule due to repeated stimulation by a bicycle saddle.

Four Japanese male students, aged 14, 16, 18 and 19, were found to have a nodule in their coccygeal regions. The typical lesion was a rugby-ball-shaped, normal-colored or slightly erythematous nodule measuring 5 to 6 cm in its long axis. Histopathologically, it showed hyperplasia of collagen fibers and slight acanthosis. All four students rode to school by bicycle over long distances and long periods; three of them developed the nodule after they started bicycle riding to school. We found that the nodule shape corresponded to the saddle of the bicycle. X-ray abnormalities included bending or anterior dislocation of the coccyx in all cases and spina bifida in two cases. These nodules may have developed as a result of irritation of this region by the saddle of the bicycle.

Adolescent↗
PubMed2002

Skin metastasis from conventional giant cell tumor of bone: conceptual significance.

A conventional giant cell tumor of the proximal femur recurred twice locally and developed pulmonary nodules. The lung lesions were felt to be an example of "benign" metastases. Eight months after the initial presentation, the patient developed a single skin nodule on the contralateral leg. Histologic features of the skin nodule showed conventional giant cell tumor identical to the bone lesion. This nodule is a manifestation of arterial metastasis typical of any malignant tumor and seemingly contradicts the concept of "benign" metastasis.

Adult↗
PubMed1962

Electron microscopy of the bursa of Fabricius of the embryonic chick with particular reference to the lympho-epithelial nodules.

Electron microscopic studies of the bursa of Fabricius during the 15th and 16th day of embryonic development in the chick have shown the following findings in the submicroscopic structure of the cellular elements of the lympho-epithelial follicles. In the medulla, basal endodermal epithelial cells undergo mitosis and differentiation into lymphoblasts. During this transformation, there is a reduction in the amount of rough endoplasmic reticulum, an increase in the number or ribosomes, and frequently an enlargement of the Golgi complex. As lymphoblasts differentiate into medium lymphocytes there is a loss of endoplasmic reticulum, a reduction in the number of ribosomes and in the size of the Golgi complex, as well as a decrease in the number and size of mitochondria and in the size of the cell and nucleus. Cytoplasmic processes of reticular-epithelial cells extend between proliferating lymphocytic cells. Desmosomes connect stellate reticular-epithelial and basal epithelial cells but are not present in lymphocytic cells. Nuclear blebbing and vesiculation are frequently observed in the various cell forms of the developing lympho-epithelial nodules. Although lymphocytes and lymphocytopoietic activities in the cortex are sparse during this stage of embryonic development of the bursa, transitional forms between mesenchymal cells and lymphoblasts have been encountered. In addition, lymphoblasts and/or undifferentiated epithelial cells occasionally may pass through the basement membrane from the medulla into the cortical region of the developing nodule. That lymphocytes in the bursa of Fabricius originate from both endodermal and mesodermal derivatives during embryonic development appears to be consistent with both light and electron microscopic observations.

Animals↗
PubMed2001

Sugar-binding activity of pea lectin enhances heterologous infection of transgenic alfalfa plants by Rhizobium leguminosarum biovar viciae.

Transgenic alfalfa (Medicago sativa L. cv Regen) roots carrying genes encoding soybean lectin or pea (Pisum sativum) seed lectin (PSL) were inoculated with Bradyrhizobium japonicum or Rhizobium leguminosarum bv viciae, respectively, and their responses were compared with those of comparably inoculated control plants. We found that nodule-like structures formed on alfalfa roots only when the rhizobial strains produced Nod factor from the alfalfa-nodulating strain, Sinorhizobium meliloti. Uninfected nodule-like structures developed on the soybean lectin-transgenic plant roots at very low inoculum concentrations, but bona fide infection threads were not detected even when B. japonicum produced the appropriate S. meliloti Nod factor. In contrast, the PSL-transgenic plants were not only well nodulated but also exhibited infection thread formation in response to R. leguminosarum bv viciae, but only when the bacteria expressed the complete set of S. meliloti nod genes. A few nodules from the PSL-transgenic plant roots were even found to be colonized by R. leguminosarum bv viciae expressing S. meliloti nod genes, but the plants were yellow and senescent, indicating that nitrogen fixation did not take place. Exopolysaccharide appears to be absolutely required for both nodule development and infection thread formation because neither occurred in PSL-transgenic plant roots following inoculation with an Exo(-) R. leguminosarum bv viciae strain that produced S. meliloti Nod factor.

Carbohydrate Metabolism↗
PubMed1987

The reduction in microfilariae loads in the skin and eye after nodulectomy in Ecuadorian onchocerciasis.

This study is concerned with the relationship between palpable onchocercal nodules and Onchocerca volvulus microfilarial loads in the skin. The number of microfilariae in clinically normal skin decreases as the distance from the nodule increases. Surgical removal of nodules reduces the microfilarial loads in 40 of 46 patients studied over a period of five months, with an average reduction of 65.4% of the prenodulectomy microfilarial load at the iliac crest. Complete elimination of detectable parasites was seen in some patients. Five individuals had increased microfilarial loads, all of which had developed new palpable nodules. Also, nodulectomy had a significant effect on ocular tissue, reducing the levels of parasites in the cornea and anterior chamber in 10 of 15 patients observed with no new nodules developing during the observation period. Both dermal and ocular clinical manifestations of onchocerciasis were reduced in a proportion of the patients. These parasitological and clinical findings provide evidence that nodulectomy is a beneficial procedure to O. volvulus infected patients in Ecuador by reducing both microfilarial loads and the degree of pathology.

Animals↗
PubMed1986

Liver scarring induced by polychlorinated biphenyl administration to mice previously treated with diethylnitrosamine.

Exposure of mice for 8 weeks to drinking water containing diethylnitrosamine (DEN) was accompanied by alterations in hepatocyte structure and varying degrees of liver nonparenchymal cell (NPC) proliferation. Eighteen and a half weeks after cessation of DEN exposure, there was a 47% incidence of hepatocellular nodules. Centrilobular hepatocyte hypertrophy occurred consistently in mice given intraperitoneal injections of the polychlorinated biphenyl (PCB) mixture Aroclor 1254. PCB administration to mice previously treated with DEN was not accompanied by increases in gross liver nodule incidence above that induced by DEN, but many more developing microscopic nodules within the liver were observed in DEN-treated mice given Aroclor 1254 than in mice treated only with DEN. Aroclor 1254 administration over a 16-week period to mice previously treated with DEN was accompanied by an 83% incidence of severe distortion of liver structure resulting from nodule formation, uneven patterns of hepatocyte growth, and extensive deposition of scar tissue containing proliferating bile ducts. Morphological evidence of intestinal metaplasia was observed in proliferating bile duct-like structures during an early stage of liver adenofibrosis.

Animals↗
PubMed1993

[Is it appropriate to treat thyroid nodules with thyroid hormone?].

The appropriateness of treating thyroid nodules with thyroid hormone is being debated: in fact, the development of nodules is not caused by an iodothyronine deficiency or a desuppression of TSH, and T4 seems to be able to regain control on cell proliferation. A very great number of authors have reported their experience with suppression of thyroid nodules with thyroid hormone, but treatment efficacy has been variably appreciated (9 to 69% regression). On the other hand, the four randomized prospective studies available at present, which analyze the evolution of nodules, especially on ultrasonography, have not demonstrated that hormone therapy is more effective than a placebo. The methodology of these studies is not free from criticism, and other prospective surveys are required, especially to establish whether this treatment is innocuous and whether some varieties of nodules may be more amenable to hormone therapy than others.

Humans↗
PubMed1991

N-Acetylglutamic acid: an extracellular nod signal of Rhizobium trifolii ANU843 that induces root hair branching and nodule-like primordia in white clover roots.

An extracellular metabolite purified from Rhizobium trifolii ANU843 was established as N-acetylglutamic acid (GluNAc) by 1H NMR and Fourier transform IR spectroscopy, gas chromatography/mass spectrometry of its methylated product, and organic synthesis. TLC analyses indicated that extracellular accumulation of GluNAc by R. trifolii ANU843 grown in defined BIII culture medium was dependent on induction of its bacterial nodulation (nod) genes and the positive regulatory gene nodD on its symbiotic plasmid. 1H NMR analyses showed less GluNAc in fractionated culture supernatants of nodL and nodM mutant derivatives of R. trifolii ANU843. GluNAc induced three morphological responses on axenic roots of white clover seedlings: (i) root hair branching; (ii) tip swelling followed by resumed elongation of root hairs; and (iii) a slight increase in foci of cortical cell divisions, which developed into nodule-like primordia. These biological activities of extracellular GluNAc from R. trifolii ANU843 were confirmed with authentic standards of GluNAc. These results indicate that extracellular accumulation of N-acetylglutamic acid is linked to flavone-dependent metabolism involving nodD, nodL, and nodM in R. trifolii ANU843. This constitutes the first report on the structure of a nod-dependent extracellular signal from R. trifolii that can affect root hair and nodule development in white clover and whose biological activity on this host has been confirmed with authentic standards.

Flavonoids↗
PubMed1984

Alteration of the development of mammary hyperplastic alveolar nodules and uterine adenomyosis in SHN mice by different schedules of treatment with CB-154.

The effect of different schedules of bromocriptine-mesilate (CB-154; 0.2 mg/day) treatment on the development of precancerous mammary hyperplastic alveolar nodules (HAN) and uterine adenomyosis was investigated in a virgin SHN strain of mice. CB-154 treatment for 7 weeks beginning at 4 weeks of age enhanced the development of HAN at an advanced age, the shorter period of treatment having no effect. In contrast, spontaneous development of adenomyosis was markedly inhibited in mice treated with CB-154 for more than 4 weeks beginning at 4 weeks of age, but not for less than 3 weeks of the treatment. The inhibitory effect of CB-154 was not counteracted by pituitary grafting. Furthermore, CB-154 treatment between 11 and 18 weeks of age also accelerated HAN formation, but had no effect on the development of adenomyosis. These results indicate that in mice a certain period of CB-154 treatment is necessary to produce changes in the development of HAN and adenomyosis, and that the inhibitory effect of CB-154 on the development of adenomyosis is age-dependent. The different response between mammary gland cells and uterine cells to CB-154 exposure is discussed with special reference to cell proliferation.

Age Factors↗
PubMed1988

The development of a solitary toxic thyroid nodule following Graves' disease.

A 52-year-old woman developed a toxic, solitary, autonomously functioning thyroid nodule four years after antithyroid drug treatment for Graves' disease. When she was initially seen, a thyroid scan showed the homogeneous enlargement of both lobes with increased uptake. Graves' disease was diagnosed and the patient was treated with methimazole. Thyroid function was well-controlled with medication for 18 months, after which the patient stopped taking the drug for three years. Four years after Graves' disease was diagnosed, the patient again showed symptoms of hyperthyroidism. The etiology was a toxic, autonomously functioning nodule.

Female↗
PubMed2006

Mapping a sex hormone-sensitive gene determining female resistance to liver carcinogenesis in a congenic F344.BN-Hcs4 rat.

Hepatocellular carcinoma (HCC) is prevalent in human and rodent males. Hepatocarcinogenesis is controlled by various genes in susceptible F344 and resistant Brown Norway (BN) rats. B alleles at Hcs4 locus, on RNO16, control neoplastic nodule volume. We constructed the F344.BN-Hcs4 recombinant congenic strain (RCS) by introgressing a 4.41-cM portion of Hcs4 from BN strain in an isogenic F344 background. Preneoplastic and neoplastic lesions were induced by the "resistant hepatocyte" protocol. Eight weeks after initiation, lesion volume and positivity for proliferating cell nuclear antigen (PCNA) were much higher in lesions of F344 than BN rats of both sexes. These variables were lower in females than in males. Lesion volume and PCNA values of male RCS were similar to those of F344 rats, but in females corresponded to those of BN females. Carcinomatous nodules and HCC developed at 32 and 60 weeks, respectively, in male F344 and congenics and, rarely, in F344 females. BN and congenic females developed only eosinophilic/clear cells nodules. Gonadectomy of congenic males, followed by beta-estradiol administration, caused a decrease in Ar expression, an increase in Er-alpha expression, and development of preneoplastic lesions comparable to those from BN females. Administration of testosterone to gonadectomized females led to Ar increase and development of preneoplastic lesions as in F344 males. This indicates a role of homozygous B alleles at Hcs4 in the determination of phenotypic patterns of female RCS and presence at Hcs4 locus of a high penetrance gene(s), activated by estrogens and inhibited/unaffected by testosterone, conferring resistance to females in which the B alleles provide higher resistance.

Animals↗
PubMed2005

Symbiotic leghemoglobins are crucial for nitrogen fixation in legume root nodules but not for general plant growth and development.

Hemoglobins are ubiquitous in nature and among the best-characterized proteins. Genetics has revealed crucial roles for human hemoglobins, but similar data are lacking for plants. Plants contain symbiotic and nonsymbiotic hemoglobins; the former are thought to be important for symbiotic nitrogen fixation (SNF). In legumes, SNF occurs in specialized organs, called nodules, which contain millions of nitrogen-fixing rhizobia, called bacteroids. The induction of nodule-specific plant genes, including those encoding symbiotic leghemoglobins (Lb), accompanies nodule development. Leghemoglobins accumulate to millimolar concentrations in the cytoplasm of infected plant cells prior to nitrogen fixation and are thought to buffer free oxygen in the nanomolar range, avoiding inactivation of oxygen-labile nitrogenase while maintaining high oxygen flux for respiration. Although widely accepted, this hypothesis has never been tested in planta. Using RNAi, we abolished symbiotic leghemoglobin synthesis in nodules of the model legume Lotus japonicus. This caused an increase in nodule free oxygen, a decrease in the ATP/ADP ratio, loss of bacterial nitrogenase protein, and absence of SNF. However, LbRNAi plants grew normally when fertilized with mineral nitrogen. These data indicate roles for leghemoglobins in oxygen transport and buffering and prove for the first time that plant hemoglobins are crucial for symbiotic nitrogen fixation.

Adenosine Triphosphate↗
PubMed1989

Effects of dexamethasone on expression and maintenance of cartilage in serum-containing cultures of calvaria cells.

The effects of dexamethasone on the ability of cells enzymatically isolated from 21-day fetal rat calvaria to produce cartilage in vitro has been investigated. Primary cultures of single-cell suspensions of rat calvaria were grown for up to 28 days in vitro in alpha-minimal essential medium containing 15% fetal bovine serum, 50 micrograms/ml ascorbic acid, 10 mM Na beta-glycerophosphate and dexamethasone at concentrations of 1 microM to 1 nM. Two types of nodules were present in dexamethasone-containing cultures. One has been characterized previously as bone (Bellows et al. 1986). The second morphologically resembled hyaline cartilage, possessed a strong Alcian blue-positive matrix and contained type-II, but not type-I, collagen. Both bone and cartilaginous nodules were spatially distinct and developed in isolation from each other. Cartilaginous nodules were found in the highest number at a dexamethasone concentration of 100 nM. Time-course experiments revealed that while the number of bone nodules increased continuously at least to day 28, the number of cartilaginous nodules remained constant after cultures had reached confluency. When cells were isolated separately from frontal and parietal bones and sutural regions, the greatest number of cartilaginous nodules developed from parietal bones. Since 21-day fetal rat calvaria contains 2 distinct patches of cartilage at the periphery of the parietal bones, it seems likely that this cartilaginous tissue is the origin of the cartilage cells. The results demonstrate that cultures of rat calvaria cells contain chondrocytes and possibly chondroprogenitor cells that are distinct from osteoprogenitors.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Breast nodules as the initial site of relapse in childhood leukemia.

Two children with acute monoblastic leukemia in remission developed breast nodules that were the initial sites of disease relapse. Shortly after the appearance of disease in this site, the children developed marrow recurrence and, despite additional treatment, rapidly deteriorated and died from pancytopenia-related complications. The importance of careful breast examination is stressed as part of the surveillance physical examination for children with monoblastic leukemia.

Adolescent↗
PubMed1996

Thyroid cancer in children, pregnant women, and patients with Graves' disease.

Differentiated thyroid cancer may have a different clinical course when it develops in children, pregnant women, and patients with Graves' disease. Thyroid nodules which develop in these patients appear to have a greater risk of malignancy and should be evaluated aggressively. Treatment in all cases includes operation followed by radioactive iodine ablation (in the nonpregnant patient) and thyroid hormone suppression. Follow-up, including serum Tg and yearly thyroid scans, should be continued as long as possible.

Adolescent↗
PubMed1995

The pulmonary nodule after lung transplantation. Cause and outcome.

In the immunocompromised patient, the pulmonary nodule remains a diagnostic and therapeutic challenge. We studied the incidence, cause, diagnosis, and therapy of pulmonary nodules after lung transplantation (LTx). Eight out of 64 patients (12.5%) developed pulmonary nodules after a median follow-up of 5.8 months (range, 1 to 10 months). The median age was 30.5 years (range, 21 to 62 years). Solitary pulmonary nodules (n = 2) disappeared spontaneously within 3 weeks and were suspected to be of infectious origin. The cause of multiple nodules (n = 6) was posttransplant lymphoproliferative disorder (PTLD [n = 3]), aspergillosis (n = 2), and abscesses caused by Pseudomonas aeruginosa and Staphylococcus aureus (n = 1). After an initial chest radiograph, CT with fine-needle biopsy was the most valuable diagnostic tool. In six patients, nodules resolved within 10 weeks (median, 8 weeks). Two patients, however, died of sepsis (P aeruginosa and S aureus and Aspergillus, respectively). The differential diagnosis of pulmonary nodules after LTx primarily comprises PTLD and infection (bacterial or fungal). To improve the outcome, early, aggressive treatment is mandatory; therefore, serial CT scans are strongly recommended to be part of the diagnostic armamentarium in LTx recipients.

Adult↗
PubMed1985

Histochemistry of liver tumors induced by diethylnitrosamine and differential sex susceptibility to carcinogenesis in Oryzias latipes.

Liver tumor nodules were induced by the administration of diethylnitrosamine [(DENA) CAS: 55-18-5; N-nitrosodiethylamine] to the fish, Oryzias latipes. A histochemical study showed decreased ATPase and glucose 6-phosphatase (Glc-6-Pase) activities in most of the tumor nodules. Increased ATPase staining and, occasionally, Glc-6-Pase staining were also observed. In some nodules, the distribution of bile canaliculi was disordered, indicating positive ATPase activity. Basophilic and eosinophilic nodules could be discriminated by histologic examination. The observations on serial histochemical and histologic sections revealed extreme heterogeneity in the phenotypes of the nodules. Measurement of the enzyme-altered areas indicated that the development of nodules was more prominent in male than in female fish. Experiments with sex-reversed fish, XX males and XY females, suggested that the sex difference in the susceptibility to DENA does not result from the difference in sex chromosomes but from the difference in sexual phenotypes.

Adenosine Triphosphatases↗
PubMed2006

The newly developed three-dimensional (3D) and two-dimensional (2D) thyroid ultrasound are strongly correlated, but 2D overestimates thyroid volume in the presence of nodules.

The newly developed three-dimensional (3D) and two-dimensional (2D) thyroid ultrasound (US) were compared in assessing thyroid volume (TV) in 104 patients: 53 had an isolated thyroid nodule, 32 toxic diffuse goiter, 17 non-toxic multinodular goiter, 1 toxic multinodular goiter and 1 a toxic adenoma. A real-time Technos apparatus (Esaote SpA, Italy) with a 7,5 MHz linear transducer was used. The volume of thyroid lobes by 2D was calculated according to the ellipsoid formula. In the same session, TV by 3D US was calculated using a probe tracking system (in vivo ScanNT Esaote 3.4 MedCom. Darmasdt) and software to reconstruct 3D images, directly giving the lobe volume. There was a very good agreement between 2D and 3D, but in 94/208 lobes with nodular lesions 2D showed a 10% systematic overestimation compared to 3D, the percentage error being higher in lobes with lower volumes. A possible explanation for this result is the inadequacy of the ellipsoid formula in forecasting the correct lobe profile in the presence of nodules. This intrinsic defect of 2D US should be taken into account when evaluating TV in patients with nodular goiter.

Adenoma↗