Biosynthesis of two molecular forms of ceruloplasmin in rat liver and their polar secretion into the blood stream and bile

Biosynthesis and secretion of ceruloplasmin (CP) in rat liver has been studied in order to elucidate its role in the distribution, transport and excretion of copper in the body. The kinetics and topography of CP synthesis, intracellular transport and secretion were followed using in vivo pulse-chase experiments. It was found that the newly formed CP was firmly bound to endoplasmic reticulum membranes in the hepatocytes. Liver slices incubated in vitro with [35S]methionine were characterized by a two-stage release of [35S]CP into the medium. After 30-min incubation the medium contained 200 kDa CP-like protein, while after 120 min the secretion of 130 kDa CP was demonstrated. The pulse-labelling experiments with [35S]methionine in rats with catheters inserted into the carotid artery and the common bile duct revealed the polar secretion of two distinct CP species differing in molecular structure and secretion rate. The slowly secreted CP isoform is the authentic serum CP, while the rapidly secreted CP is the specific biliary CP. The physiological function of biliary CP and its role in the pathogenesis of Wilson's disease are discussed.     

Leukocyte differentials predict short-term clinical outcome following antipsychotic treatment in schizophrenia

PURPOSE: The purpose of the test-retest phase of the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study was to determine the repeatability of the various parts of the CLEK Study protocol. This paper presents the test-retest parameters of the refraction protocol. METHODS: We examined 138 CLEK Study-eligible patients on two occasions (median, 90 days; range, 22 to 268 days). All patients underwent subjective refraction on two occasions, and contact lens over-refractions were performed either over the patient's habitual rigid contact lenses or over a trial rigid contact lens equal in base curve to the steep keratometric reading in nonrigid contact lens wearers. RESULTS: Mean interoccasion differences +/- SD were -0.32 +/- 2.91 D and -0.17 +/- 1.39 D for subjective refraction sphere and cylinder power, respectively, and the mean absolute difference for subjective refraction cylinder axis was 18.1 +/- 20.2 degrees. The mean interoccasion difference +/- SD for high-contrast visual acuity with subjective refraction was 0.38 +/- 10.9 letters correct. Mean interoccasion differences +/- SD were -0.11 +/- 0.81 D and 0.02 +/- 0.67 D for contact lens over-refraction sphere and cylinder power, respectively, and the mean absolute difference for contact lens over-refraction cylinder axis was 11.6 +/- 9.9 degrees. The mean interoccasion difference +/- SD for visual acuity with contact lens over-refraction was 0.50 +/- 5.2 letters correct and 0.71 +/- 6.9 letters correct for high- and low-contrast visual acuity, respectively. CONCLUSIONS: The repeatability of subjective refraction in keratoconus patients is good but somewhat lower than that found in nondiseased eyes. Only 36% of our repeat measures of sphere power from subjective refraction fell within 0.50 D of each other, compared with more than 90% in studies of normal eyes.     

Nonneoplastic disorders of the eccrine glands

Eccrine glands are uniquely susceptible to a variety of pathologic processes. Alteration in the rate of sweat secretion manifests as hypohidrosis and hyperhidrosis. Obstruction of the eccrine duct leads to miliaria. The excretion of drugs into eccrine sweat may be a contributory factor in neutrophilic eccrine hidradenitis (NEH), syringosquamous metaplasia (SSM), coma bulla, and erythema multiforme (EM). Alterations in the electrolyte composition of eccrine sweat can be observed in several systemic diseases, most notably cystic fibrosis. This article summarizes current knowledge of eccrine gland pathophysiology.     

The bacterial endotoxin lipopolysaccharide causes rapid inappropriate excitation in rat cortex

There is mounting evidence that inflammation and associated excitotoxicity may play important roles in various neurodegenerative disorders, such as bacterial infections, Alzheimer's disease, AIDS dementia, and multiple sclerosis. The immunogen E. coli lipopolysaccharide (LPS, endotoxin) has been widely used to stimulate immune/inflammatory responses both systemically and in the CNS. Here, we show that exposure of parietal cortical slices from adult rats to LPS triggered very rapid (<2.5 min) and sustained releases of the neurotransmitters glutamate and noradrenaline, and of the neuromodulator adenosine. The responses to LPS declined rapidly following removal of the LPS and exhibited no tachyphylaxis to repeated exposures to LPS. The detoxified form of LPS had no effect. LPS-evoked release of [3H]noradrenaline, but not of glutamate or adenosine, appears to be partly due to the released glutamate acting at ionotropic receptors on the noradrenergic axons present in the cortical slices. LPS appears to release glutamate, which then acts at non-NMDA receptors to remove the voltage-sensitive Mg2+ block of NMDA receptors, thus permitting NMDA receptors to be activated and noradrenaline release to proceed. It seems possible that rapid, inappropriate excitation may occur in the immediate vicinity of gram-negative bacterial infections in the brain. If similar inappropriate excitations are also triggered by those immunogens specifically associated with Alzheimer's disease (beta-amyloid), AIDS dementia (gp120 and gp41), or multiple sclerosis (myelin basic protein), they might explain some of the acute, transient neurological and psychiatric symptoms associated with these disorders.     

Accelerated evolution of cytochrome b in simian primates: adaptive evolution in concert with other mitochondrial proteins?

We have devised a practical, sensitive and specific method for simultaneous measurement of free thyroxine (FT4) and free triiodothyronine (FT3) in undiluted serum by direct equilibrium dialysis radioimmunoassay (RIA). Two hundred microliters serum sample was dialyzed against buffer (pH 7.4) for 20 hours at 37 degrees C and approximately 800 microL of the dialysate was used for measuring FT4 and FT3 simultaneously. The assay was set up in polystyrene tubes coated with anti-T4 antibody and available commercially for FT4 measurement (Quest-Nichols Institute, San Juan Capistrano, CA). The mean +/- SE (range) FT4 concentration (ng/dL) was 1.2 +/- 0.04 (0.7.0 to 2.30) in 54 normal subjects. It was significantly increased (3.6 +/- 0.4 [1.8 to 9.6], n = 20) in hyperthyroidism and clearly decreased (0.40 +/- 0.04 [1.10 to 0.70], n = 26] in hypothyroidism. All nonthyroid illness (NTI) patients had normal FT4 except 3, 2 of whom were on amiodarone and 1 had received heparin. Serum FT4 concentration was minimally elevated in 18 newborn cord blood serum (1.40 +/- 0.08 [0.90 to 2.2], cf. normal p < .05). The mean serum FT3 concentration (pg/dL) was 285 +/- 10 (134 to 454) in 54 normal sera. It was clearly increased in hyperthyroidism (1033 +/- 98 [593 to 2134], n = 20, p < .001). However, serum FT3 varied widely in hypothyroidism (27 to 597, mean 235 +/- 24, NS) as did serum total T3 (19 to 175). Interestingly, however, the mean serum FT3 concentration was normal (273 +/- 28 [62 to 575, NS]) in 25 NTI patients. All of these patients had low serum total T3 (46 +/- 5.0 [10 to 84], ng/dL; normal 84 to 160, p < 0.001), while FT3 was clearly normal in 21 of 25 patients and low in the remaining 4 patients. Similarly, among 18 newborn cord blood sera serum FT3 concentration was normal in 15 and subnormal only in the remaining 3 while all had clearly subnormal total T3 (28 to 74 ng/dL). CONCLUSIONS: (1) A practical, sensitive, and specific assay for simultaneous measurement of FT4 and FT3 is described; (2) FT3 is consistently elevated in hyperthyroidism while FT4 is elevated in most (approximately 85%) cases; (3) FT4 is consistently decreased in hypothyroidism but FT3 varies widely; (4). Serum FT3 concentration is normal in approximately 83% of patients with the low T3 syndrome in NTI and newborn cord blood serum. These data suggest that normal FT3 may explain clinical euthyroidism in many patients with the low T3 syndrome.     

Development of transplantation vasculopathy and progression of donor-transmitted atherosclerosis: comparison by serial intravascular ultrasound imaging

BACKGROUND: Transplant coronary artery disease is a combination of atherosclerosis transmitted from the donor and new lesions of allograft vasculopathy. We sought to determine the morphological characteristics of allograft vasculopathy and differentiate it from donor-transmitted atherosclerosis with serial intravascular ultrasound. METHODS AND RESULTS: Intravascular ultrasound examination was performed in 93 patients at 27.2+/-15.0 and 369. 7+/-23.9 days after transplantation. The maximally and minimally diseased sites were selected in each segment as defined by Coronary Artery Surgery Study classification. For each matched site, maximal plaque thickness was measured. Lesions (maximum plaque thickness >/=0.5 mm) present at baseline examination were defined as donor lesions. On follow-up, lesions that developed at previously normal sites were defined as de novo lesions. The distribution and severity of donor and de novo lesions were similar in proximal, mid, and distal segments. The de novo lesions were less focal (43% vs 74%) and more circumferential (69% vs 45%) compared with the donor lesions, but there was significant morphological heterogeneity. Similar numbers of patients with and those without donor lesions developed de novo lesions. Moreover, progression of donor lesions was not associated with the presence or absence of de novo lesions. CONCLUSIONS: Differentiation between early allograft vasculopathy from conventional atherosclerosis by distribution and morphology of lesions alone is difficult. Serial intravascular ultrasound imaging with early baseline examination is necessary to make this distinction. This distinction is important because the progression of donor lesions and the development of de novo lesions are independent of each other.     

Transport and activation of the vacuolar aspartic proteinase phytepsin in barley (Hordeum vulgare L.)

The primary translation product of barley aspartic proteinase, phytepsin (EC 3.4.23.40), consists of a signal sequence, a propart, and mature enzyme forms. Here, we describe post-translational processing and activation of phytepsin during its transport to the vacuole in roots, as detected by using metabolic labeling and immunoprecipitation. After removal of the signal sequence, the glycosylated precursor of 53 kDa (P53) was produced and further processed to polypeptides of 31 and 15 kDa (P31 + P15) and, subsequently, to polypeptides of 26 and 9 kDa (P26 + P9), 45 min and 24 h after synthesis, respectively. The processing occurred in a late-Golgi compartment or post-Golgi compartment, because brefeldin A inhibited the processing, and P53 acquired partial endoglycosidase H resistance 30 min after synthesis, whereas P15 was completely resistant. The N-glycosylation inhibitor tunicamycin had no effect on transport, but the absence of glycans on P53 accelerated the proteolytic processing. Phytepsin was also expressed in baculovirus-infected insect cells. The recombinant prophytepsin underwent autoproteolytic activation in vitro and showed enzymatic properties similar to the enzyme purified from grains. However, a comparison of the in vitro/in vivo processing sites revealed slight differences, indicating that additional proteases are needed for the completion of the maturation in vivo.     

Individual and combined effects of fumonisin B1 present in Fusarium moniliforme culture material and diacetoxyscirpenol or ochratoxin A in turkey poults

The individual and combined effects of feeding diets containing 300 mg fumonisin B1 (FB1), and 4 mg diacetoxyscirpenol (DAS) or 3 mg ochratoxin A (OA) were evaluated in two experiments using female turkey poults (Nicholas Large Whites) from day of hatch to 3 wk of age. When compared with controls, body weight gains were reduced 30% (Study 1) and 24% (Study 2) by FB1, 30% by DAS, 8% by OA, 46% by the FB1 and DAS combination, and 37% by the FB1 and OA combination. The efficiency of feed utilization was adversely affected by all treatments except FB1 in Experiment 2. Relative weights of the liver were significantly increased by all treatments except the DAS treatment. Serum concentrations of cholesterol were decreased and activities of aspartate aminotransferase and lactate dehydrogenase were increased and several hematological values were altered in poults fed FB1 alone and in combination with either DAS or OA. Results indicate additive or less than additive toxicity, but not toxic synergy, when poults are fed diets containing 300 mg FB1, and 4 mg DAS or 3 mg OA/kg of diet. The likelihood of encountering FB1, DAS, or OA at these concentrations in finished feed is small. However, under field conditions, other stress factors could alter the impact of these mycotoxins on the health and performance of poultry.     

Clusters of Bell's palsy

The idiopathic facial paralysis or Bell's palsy installs abruptly or within a few hours, without any apparent cause. It corresponds to approximately 75% of all peripheral facial palsies. Three theories try to explain its pathogenecity: vascular-ischemic, viral and auto-immune. We reviewed the records of the EMG Sector, Hospital do Servidor Público Estadual (S?o Paulo, Brazil), from 1985 to 1995 and found 239 cases of Bell's palsy. Data were analysed according to age, gender, seasonal distribution of cases. There was a predominance of cases in the 31-60 age bracket (40.59%). The female gender was responsible to 70.71% of cases. There was a predominance of cases in winter (31.38%) and autumn (30.13%), which was statistically significant. These findings let us to suppose that Bell's palsy predominates in females, in 41-60 years age bracket, and occurs predominantly in cold months. There are groups of clusters throughout temporal distribution of cases and cases are dependent on one each other or on factors affecting them all, which reinforces the infectious hypothesis (there is a rise in the incidence of viral upper respiratory tract infection during cold months).