Thyroid nodular disease: is it toxic or nontoxic, malignant or benign?

The thyroid gland is known to become more nodular with age. The clinical questions in a given patient are whether the nodule(s) is benign or malignant and euthyroid or toxic. Toxic multinodular goiter (MNG) is more common in the elderly than Graves' disease but is not associated with the classic eye or skin findings.

Detection and treatment of hypothyroidism and Graves' disease.

The clinical presentations of thyroid disorders are often subtle in older adults and may be confused with "normal" aging. To avoid delay in diagnosis, we recommend routine TSH screening of all patients age 60 and older in the primary care practice. With hypothyroidism, pursue treatment cautiously; start with small doses of levothyroxine and closely monitor serum TSH values.

An evaluation of competitor type and size for use in the determination of mRNA by competitive PCR.

The technique of competitive PCR for measuring mRNA is used widely. Several variations of the method have been reported. We have evaluated some of the commonly used competitor types as part of our study into expression of the androgen receptor (AR).

Increased hypothalamic somatostatin expression in mice transgenic for bovine or human GH.

Acute studies of GH removal by hypophysectomy or GH replacement in adult rats have shown that GH has a positive influence on its hypothalamic inhibitory hormone somatostatin (SRIH). The present study was undertaken to assess the effect of lifelong exposure to elevated GH on the development and differentiation of SRIH-producing hypothalamic neurons, including comparison of differing GH levels and heterologous species of GH. Expression of somatostatin peptide and mRNA was evaluated using respective immunocytochemistry and in situ hybridization in brains of transgenic mice bearing constructs of either human (hGH) or bovine (bGH) linked to metallothionein (MT) promoter or bGH linked to phosphoenolpyruvate carboxykinase (PEPCK) promoter.

The short-term effect of low concentrations of dietary aflatoxin and T-2 toxin on mallard ducklings.

Two 9-day trials to study effects of dietary mycotoxins were conducted using 6-week-old mallards. Each trial involved three groups of six ducks each, three males and three females per group. One group was fed no myocotoxin (control), one was fed aflatoxin, and the third was fed T-2 toxin.

Optical detection of ultrasound with a microchip laser.

A novel optical ultrasonic detector that relies on frequency modulation of a microchip laser is proposed and demonstrated. When the laser is placed in a time-varying acoustic field, the microchip laser cavity length is periodically modulated, creating a frequency-modulated optical output in which the frequency shift is linearly proportional to the acoustic-wave amplitude. With a confocal Fabry-Perot slope filter and a Nd:YAG microchip laser operating at 1.

Postnatal reduction in number of hypothalamic tuberoinfundibular dopaminergic neurons in prolactin-deficient dwarf mice.

Mice homozygous for the recessive 'Ames' dwarf mutation have undetectable serum or pituitary prolactin (PRL). Accompanying this pituitary deficiency is a marked reduction of dopamine (DA) and its rate-limiting synthetic enzyme tyrosine hydroxylase (TH) in PRL-regulating tuberoinfundibular hypothalamic neurons. In order to determine whether this deficit in adult Ames dwarf mice is congenital or arises postnatally, brains of dwarf (df/df) and normal (DF/?) littermate mice were assessed for TH immunoreactivity from 7 days through 2 months of age.

Characterization of resting and phorbol ester or concanavalin A activated bovine lymph node cells with leukocyte specific monoclonal antibodies.

Bovine lymph node cells (LNC) have been used as a model to study cell activation and proliferation. Because monoclonal antibodies to bovine lymphoid-specific surface antigens have only recently become available, these cells have not been previously characterized in regard to subpopulations. Furthermore, it was not known how expression of lymphoid differentiation antigens and subset proportionalities might change following different modes of activation of LNC.

The opiate system in invertebrates.

The presence in diverse species of a similar mode of communication, that of a soluble messenger binding to a receptor, raises the question as to whether the specific components of this system are equally widespread. Do invertebrates use the same hormones and receptors as vertebrates do? Invertebrates ranging from unicellular organisms to insects have been shown to contain opiate-like peptides and binding sites, and they exhibit biological responses to opiates. However, critical genetic data are lacking.

Prolonged remission of metastatic follicular thyroid carcinoma.

Follicular thyroid carcinoma is associated with an extremely poor prognosis when metastatic lesions occur. Although radioiodine therapy for metastatic disease can extend patient survival for several years, its effect is usually only palliative. Herein we describe a 47-year-old man with metastatic follicular thyroid carcinoma who was in clinical remission for 30 years after surgical and radioiodine treatment of the original disease.

Growth hormone-releasing hormone peptide and mRNA are overexpressed in GH-deficient Ames dwarf mice.

Hypothalamic expression of growth hormone-releasing hormone (GHRH) was quantified morphologically in dwarf mice which exhibit spontaneous genetic GH absence. Mouse GHRH mRNA was assessed by in situ hybridization; densitometric evaluation of total mRNA in dwarfs showed levels 2.3-fold higher than in phenotypically normal siblings (p < 0.

Altered growth hormone-releasing hormone mRNA expression in transgenic mice with excess or deficient endogenous growth hormone.

Hypothalamic expression of growth hormone-releasing hormone (GHRH) mRNA was examined in two transgenic mouse models displaying excess or deficient endogenous GH. Transgenic dwarf mice bore a gene construct consisting of the rat growth hormone (GH) promoter fused to a diphtheria toxin A chain structural gene (DT-A); the GH promoter restricted DT-A expression to endogenous GH-producing cells, which were destroyed. GH was undetectable in either the pituitary or the peripheral circulation (Behringer et al.

Immunocompromise in gnotobiotic pigs induced by verotoxin-producing Escherichia coli (O111:NM).

A verotoxin-producing Escherichia coli serotype O111:NM strain (strain 10049; verotoxin 1 positive) persistently infected experimentally inoculated gnotobiotic pigs, causing attaching-effecting intestinal lesions and chronic diarrhea. Experiments were performed to determine whether persistent infection might be associated with immunocompromise of the host of this organism. Pigs inoculated with this strain had a significant reduction in peripheral blood lymphocytes and lower antibody titers to sheep erythrocytes compared with control pigs.

Acquired hypophosphatemia.

This article discusses the regulation of serum phosphorus under normal conditions, focusing on the pathophysiology of acquired hypophosphatemia and its clinical manifestation. In addition, the clinical settings and conditions in which hypophosphatemia is likely to cause severe morbidity are emphasized.

Familial glucocorticoid resistance caused by a splice site deletion in the human glucocorticoid receptor gene.

The clinical syndrome of generalized, compensated glucocorticoid resistance is characterized by increased cortisol secretion without clinical evidence of hyper- or hypocortisolism, and manifestations of androgen and/or mineralocorticoid excess. This condition results from partial failure of the glucocorticoid receptor (GR) to modulate transcription of its target genes. We studied the molecular mechanisms of this syndrome in a Dutch kindred, whose affected members had hypercortisolism and approximately half of normal GRs, and whose proband was a young woman with manifestations of hyperandrogenism.

Localization of the tachykinin neurokinin B precursor peptide in rat brain by immunocytochemistry and in situ hybridization.

Tachykinins exert a broad range of actions in the mammalian nervous system. While much is known about the localization of peptides derived from one of the two mammalian tachykinin genes (substance P- and neurokinin A-encoding preprotachykinin), little has been reported on the localization of peptides derived from a second tachykinin gene encoding neurokinin B. Using an antiserum raised against a 30-residue peptide fragment (Peptide 2) of the protein precursor to neurokinin B, we have mapped the distribution of Peptide 2 by immunocytochemistry.

Superficial temporal artery laceration. A complication of skull tong traction.

Complications associated with the use of skull tongs are not uncommon. We report a case of superficial temporal artery injury as a complication of Gardner-Wells tong application. Chronic recurrent episodes of pulsatile bleeding from the pin site necessitated arterial ligation to control the bleeding.