Impact of sex on clinical outcome in early Multiple Sclerosis.

BACKGROUND: Previous evidence suggests sex differences in the clinical course of relapsing remitting multiple sclerosis (RRMS), but comprehensive early-stage prospective studies are lacking. We aim to quantify the impact of sex on clinical outcomes in early-stage RRMS. METHODS: Utilizing prospective cohort data, we assessed the impact of biological sex on time-to-relapse, disability progression (Expanded Disability Status Scale [EDSS]), extremity function (Nine-Hole Peg Test, Timed-25-food walk test), cognition (Paced Auditory Serial Addition Test, Symbol Digit Modalities Test), quality-of-life (Hamburg Quality of Life Questionnaire in Multiple Sclerosis, Short-Form-36), fatigue (Fatigue Severity Scale, Fatigue Scale for Motor and Cognitive functions), and depression (Beck Depression Inventory-II) in clinically isolated syndrome (CIS) or RRMS patients. Inclusion was within 12 months of symptom onset. Linear, negative binomial, mixed, and Cox models estimated male vs. female effects at the four-year follow-up including baseline-to-follow-up course. RESULTS: We included 149 patients (65.1 % female). Eighty-five completed four-year follow-up. No sex differences in time-to-relapse emerged (HR = 0.91;95 %CI = 0.53-1.58). Males had no increased risk of EDSS worsening (OR = 0.75;95 %CI = 0.21-2.35) compared to females. Similarly, minor/no sex differences emerged in other outcomes. CONCLUSIONS: Four years after first manifestation, neither disease activity (disability progression and relapse rate) nor patient-reported outcomes showed sex-related disparities in this early-MS-cohort. GOV IDENTIFIER: NCT01371071.

The antifungal mechanism of action of zinc pyrithione.

BACKGROUND: Zinc pyrithione (ZPT) is the active ingredient most commonly used in many antidandruff treatments. Despite decades of successful use to treat human scalps, little is understood about the antifungal mechanism of action of ZPT. OBJECTIVES: The objective of this study is to understand the molecular mechanism by which ZPT inhibits fungal growth, the underlying basis for its therapeutic activity. METHODS: Modern systems biology approaches, such as deletion library screening and microarray analysis, were used in combination with traditional measures of metal content, microbial growth and enzyme assays. RESULTS: It was shown that ZPT inhibits fungal growth through increased cellular levels of copper, damaging iron-sulphur clusters of proteins essential for fungal metabolism. CONCLUSIONS: The molecular basis for the antifungal activity of the commonly used active ZPT has been elucidated, more than 50 years since its introduction, as utilizing a copper toxicity mechanism that targets critical iron-sulphur proteins.

High expression of Mcl-1 in ALK positive and negative anaplastic large cell lymphoma.

AIM: To gain more insight into the genes involved in the aetiology and pathogenesis of anaplastic large cell lymphoma (ALCL). METHODS: Serial analysis of gene expression (SAGE) was undertaken on the CD4+ALK+ (anaplastic lymphoma kinase positive) ALCL derived cell line Karpas299 and as comparison on CD4+ T cells. Quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were performed on five ALCL derived cell lines and 32 tissue samples to confirm the SAGE data. RESULTS: High expression of Mcl-1 was seen in the Karpas299 cell line, whereas the two other antiapoptotic Bcl-2 family members, Bcl-2 and Bcl-X(L), were not detected in the SAGE library. Quantitative RT-PCR confirmed the high expression of Mcl-1 mRNA and low expression of Bcl-2 and Bcl-X(L) in Karpas299 and in four other ALCL cell lines. To expand on these initial observations, primary tissue samples were analysed for Mcl-1, Bcl-X(L), and Bcl-2 by immunohistochemistry. All 23 ALK+ and nine ALK- ALCL cases were positive for Mcl-1. Bcl-2 and Bcl-X(L) were expressed infrequently in ALK+ ALCL cases, but were present in a higher proportion of ALK- ALCL cases. CONCLUSION: The consistent high expression of Mcl-1 in ALK+ and ALK- ALCL suggests that Mcl-1 is the main antiapoptotic protein in this disease. The high frequency of Mcl-1, Bcl-2, and Bcl-X(L) positive ALCL cases in the ALK- group compared with the ALK+ group indicates that ALK induced STAT3 activation is not the main regulatory pathway in ALCL.

Hypoxia activates Akt and induces phosphorylation of GSK-3 in PC12 cells.

Akt is a serine/threonine kinase that has been shown to play a central role in promoting cell survival and opposing apoptosis. We evaluated the effect of hypoxia on Akt in rat pheochromocytoma (PC12) cells. PC12 cells were exposed to varying levels of hypoxia, including 21%, 15%, 10%, 5%, and 1% O(2). Hypoxia dramatically increased phosphorylation of Akt (Ser(473)). This effect peaked after 6 h exposure to hypoxia, but persisted strongly for up to 24 h. Phosphorylation of Akt was paralleled with a progressive increase in phosphorylation of glycogen synthase kinase-3 (GSK-3), one of its downstream substrates. The effect of hypoxia on phosphorylation of Akt was completely blocked by pretreatment of the cells with wortmannin (100 nM), indicating that this effect is mediated by phosphatidylinositol 3-kinase (P13K). In contrast, whereas hypoxia also strongly induced phosphorylation of the transcription factors CREB and EPAS1, these effects persisted in the presence of wortmannin. Thus, hypoxia regulates both P13K-dependent and P13K-independent signaling pathways. Furthermore, activation of the P13K and Akt signaling pathways may be one mechanism by which cells adapt and survive under conditions of hypoxia.

Merosin-negative congenital muscular dystrophy associated with extensive brain abnormalities.

Congenital muscular dystrophies (CMDs) are autosomal recessive, heterogeneous disorders. The most frequent form in the Caucasian population is classic (occidental) CMD, characterized by exclusive muscle involvement, although abnormal brain white matter signals are occasionally observed on MRI. Recently, deficiency of merosin, the laminin isoform in skeletal muscle, has been identified in classic CMD patients. In skeletal muscle, merosin is a native ligand for dystroglycan linking the extracellular matrix and dystrophin. Thus, merosin deficiency could disrupt the attachment of muscle cell to the extracellular matrix and lead to muscle cell necrosis. Since merosin is also expressed in the nervous system and has biologic activities on neurite outgrowth and Schwann cell migration, deficiency of merosin could affect the development of the nervous system. We report here two patients with merosin-negative CMD presenting extensive brain abnormalities characterized by cortical anomaly, polymicrogyria, and abnormal white matter signals.

Dolichol kinase and the regulation of dolichyl phosphate levels in developing brain.

The developmental changes of dolichol kinase activity and dolichyl phosphate levels have been studied in rat brain. Because both dolichol kinase activity and dolichyl phosphate were enriched in microsomes, detailed study of this subcellular fraction was carried out. Dolichol kinase specific activity in brain microsomes increased postnatally 3-fold to a maximum at ca. 30 days of age. This increase was observed whether exogenous dolichol was present or not and whether Zn2+ or Ca2+ was utilized as the cation for the enzyme. Zn2+ was the most effective cation in developing brain, as we have shown previously for adult brain (Sakakihara, Y. and Volpe, J.J., J. Biol. Chem., 260 (1985) 15413-15419). Although the Vmax for the enzyme increased by three-fold with development, the Km for dolichol and for CTP did not change, indicating that the developmental increase was not related to an alteration in catalytic efficiency of the enzyme. A striking and parallel increase in dolichyl phosphate levels in brain microsomes was defined with development. Levels were lowest in one-day-old animals and then increased ca. 13-fold to a maximum at 30 days of postnatal age. The parallel increase in dolichol kinase activity and dolichyl phosphate levels in microsomes of developing brain suggests that dolichol kinase is the principal determinant of cellular levels of dolichyl phosphate, the critical intermediate in the dolichol-linked pathway to glycoproteins.

Mechanisms by which proteolytic enzymes prolong the golden period of antibiotic action.

These experimental studies provide an explanation for the therapeutic value of proteolytic enzymes as adjuncts to antibiotic treatment of contaminated wounds. After wounding, a fibrinous coagulum develops on the wound surface. This coagulum surrounds the bacteria and protects them from contact with sustemically or topically administered antibiotics. Treatment of the wound surface with proteolytic enzymes disrupts the coagulum and exposes the bacteria to the action of the antibiotic. The topical use of enzymes is also associated with significant increases in the concentration of antibiotic at the wound and thus a decrease in the rate of infection.

The population dynamics and host utilization of Geomydoecus oregonus, a parasite of Thomomys bottae.

This study treats the population dynamics and host utilization of Geomydoecus oregonus Price and Emerson, a mallophagan parasite of the pocket gopher, Thomomys bottae (Eydous and Gervais). Over 135000 lice were collected from 393 gophers over a period of 20 months. Average infestation on all gophers was 357 lice. Bimonthly mean densities showed an increase in June-July of both years, and these data were statistically different from the rest. Population age structure remained relatively constant in time with 9.3% females, 7.2% males, 47.4% nymphs and 36.1% eggs. Sex-age class separation of the gophers showed juveniles of both sexes to average 86 lice; subadult males averaged 210 lice; adult males averaged 544 lice; subadult and adult females averaged 255 and 296 lice, respectively.Lice were not randomly distributed on the gopher, but were most numerous on the head and anterior dorsal body. Lice eggs were restricted to hairs around the ears and eyes of the host. Over 80% of the animals sampled had eggs restricted to that region.Embryonic development and eclosion of G. oregonus proceeded over a wide range of environmental parameters. Over 80% of the ova tested survived and hatched in conditions between 33° and 37°C and 22% and 84% relative humidity. The greatest survival was 98% at 35°C, 75% R. H. and in a 3% CO2 atmosphere.The generation time of G. oregonus was 40±6 days. Duration of embryogenesis and nymphal stadia approximated 10±2 days for each. Adult lice lived 30+ days on gophers.Age frequency mortalities were calculated as 0.02 for eggs, 0.18, 0.24, and 0.06 for nymphal instars and 0.50 for adult lice. This indicates a Type II survivorship curve.There was direct linear relationship between the number of female lice on a gopher and the number of lice eggs. The average number of eggs per female was four. Using the pivotal frequency for reproductives, it was possible to calculate R 0 for the louse at 1.272. Thus, r was equal to 0.24 per generation or 0.006 per day, and the population doubles in 2.8 generations.Speculations regarding population regulation are also included.

La Crosse and other forms of California encephalitis.

The California serogroup viruses are mosquito viruses that cause human infections on five continents. They are maintained and amplified in nature by a wide variety of mosquito vectors and mammalian hosts; they thrive in a remarkably wide variety of microclimates (eg, tropical, coastal temperate marshland, lowland river valleys, alpine valleys and highlands, high boreal deserts, and arctic steppes). In 1993, California serogroup viruses caused 71% of all cases of arboviral illness in the United States, principally La Crosse encephalitis. The 30 to 180 annual cases of La Crosse encephalitis represent 8% to 30% of all cases of encephalitis, rendering this illness the most common and important endemic mosquito-borne illness in the USA. Subclinical or mild infections are much more common. Methods and results acquired from intense study of California serogroup viruses have been applied, with benefit, to the study of the ecology and pathogenesis of many more serious human arboviral illnesses. The evolutionary potential of viruses, with particular reference to the development of more virulent strains, has been studied more closely in the California serogroup viruses than in almost any other agent of human disease.

Multiple sclerosis, acute disseminated encephalomyelitis, and related conditions.

Multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM) are conditions whose closely related pathology suggests shared pathophysiological elements, but whose clinical courses are usually, but not always quite dissimilar. The former is largely a disease of adulthood, the latter of childhood. Optic neuritis, demyelinative transverse myelitis, and Devic's syndrome are neurological syndromes that may occur as manifestations of either MS or ADEM. Patients with Miller-Fisher syndrome and encephalomyelradiculoneuropathy usually have features suggesting ADEM in combination with acute demyelinative polyneuropathy. These various conditions and other forms of ADEM share an indistinct border with encephalitides, granulomatous, and vasculitic conditions. MS, ADEM, and the pertinent syndromic subtypes, their differential diagnosis, treatment, and prognosis are considered in this review. Acute cerebellar ataxia is a syndrome that is likely to be pathophysiologically distinct from ADEM, although its occurrence as a postinfectious illness suggests a distant kinship. It is also reviewed.

Natural history and outcome of neonatal hypocalcemic and hypomagnesemic seizures.

The clinical characteristics and neurologic outcome of 15 newborn infants with seizures due to hypocalcemia and hypomagnesemia have been studied with careful exclusion of those patients who had other possible etiologies for seizures. Associated diagnoses included severe congenital heart disease in 7 of 15 (47%) patients. Possible causes for this association with congenital heart disease include a forme fruste of DiGeorge syndrome, hypocalcemia and hypomagnesemia due to critical illness, and subtle embolic cerebral ischemia. In contrast with previous studies, no abnormalities of formula milk feeding were observed. Five patients (36%) died of causes unrelated to seizures. Follow-up in 8 of 9 patients who had no cerebral insults other than neonatal seizures at a mean age of 57.8 +/- 10.5 months found neurologic abnormalities in 2 (22%), both with an endocrine etiology for hypocalcemia. We conclude that infants with severe congenital heart disease should be investigated for hypocalcemia and hypomagnesemia. Previous observations of a universally favorable neurologic outcome in newborns with hypocalcemic or hypomagnesemic seizures may be valid for those who have a nutritional etiology for the metabolic disturbance but are less relevant to the current population in whom hypocalcemia or hypomagnesemia due to errors in formula milk feeding is seldom observed. In this group, neurologic prognosis may be more related to associated medical conditions.

Reversible MRI lesions due to pegaspargase treatment of non-Hodgkin's lymphoma.

L-Asparaginase is the major induction-phase agent for treatment of acute lymphoblastic leukemia (ALL) and an important adjuvant in treatment of non-Hodgkin's lymphoma (NHL). However, L-asparaginase-induced disturbances of clotting homeostasis may result in thrombosis or hemorrhage. Thrombotic occlusion of small cerebral veins has been reported in patients with ALL treated with this agent, but have not been described in NHL patients or those treated with the long-acting synthetic congener, pegaspargase. We report a 16-year-old boy with NHL who developed a focal motor seizure 15 min after receiving intravenous pegaspargase. MRI of the brain demonstrated multiple cortical and subcortical lesions that most likely represented focal brain edema due to thrombotic venous occlusion, which improved remarkably within 3 days and completely resolved within 3 weeks without specific intervention or permanent clinical consequences. This process must be considered when such changes are detected in NHL patients.

Facial palsy in Kawasaki syndrome.

Facial nerve palsy, a very rare complication of Kawasaki syndrome, has been reported in only 25 patients. We treated a 12-week-old boy with bilateral coronary artery aneurysms due to Kawasaki syndrome who developed marked unilateral peripheral facial nerve palsy on day 36 of illness. None of the 25 previously reported patients with this complication were treated with immunoglobulin; they required 7 to 90 days to recover. In our patient, treatment with this agent was associated with complete resolution of facial nerve palsy within 36 hours. Review of prior cases demonstrates that children with Kawasaki-associated facial nerve palsy have more than twice the risk for coronary artery aneurysm (52% vs <25%) as that of children who do not develop this neurological complication. Unexplained facial nerve paralysis in young children with a prolonged febrile illness should provoke consideration of Kawasaki syndrome and of echocardiography to exclude coronary artery aneurysms. Although facial palsy appears likely to resolve in all patients that survive the acute phase of Kawasaki syndrome, treatment with intravenous immunoglobulin appears to considerably shorten the time to full recovery and provides an important clue to the mechanisms of neurological injury in this illness.

Congenital myopathy with ringlike distribution of myonuclei and mitochondria and accumulation of nemaline rods. A variant of centronuclear myopathy?

Histopathologic and ultrastructural findings in a muscle biopsy performed on an 11-year old boy with congenital hypotonia, weakness, respiratory insufficiency requiring chronic ventilatory support, and a probable X-linked inheritance are presented. The muscle biopsy disclosed a peculiar, ringlike arrangement of mitochondria and myonuclei in most muscle fibers. Accumulations of nemaline rods were present in approximately 10-15% of fibers. We believe that our patient represents a variant of myotubular/centronuclear myopathy. The histochemical findings suggest disturbance in developmental migration of nuclei and mitochondria probably due to impaired function of the cytoskeleton.

Diet- and valproate-induced transient hyperammonemia: effect of L-carnitine.

Hyperammonemia is an adverse effect of valproate (VPA) treatment. In particular, transient hyperammonemia has been reported to occur in VPA-treated patients after protein-rich meals. This phenomenon may occur secondary to a VPA-mediated carnitine insufficiency. We sought to confirm that protein ingestion would result in transient hyperammonemia and to determine whether supplementation with L-carnitine would prevent this effect. We studied the effect of consumption of a standardized protein-rich meal (45 g protein) before (phase I) and after (phase II) administration of L-carnitine 50 mg/kg/day for 7 days in 11 epileptic children (13.3 +/- 2.3 years of age) receiving VPA. Venous blood was obtained during fasting (baseline) and at 2 and 4 hours after the protein-rich meal for analysis of ammonia (NH3), and VPA concentrations. Mean VPA trough concentrations did not differ significantly at any time. After protein ingestion, 2-hour NH3 concentration increased by 86% (P < .05) from baseline in phase I as compared with a 38% increase in phase II. In both phases I and II, 4-hour NH3 concentrations decreased toward baseline values. We conclude that (1) modest protein ingestion can result in significant transient increases in NH3 in VPA-treated children, (2) significant increases may occur in patients with normal fasting NH3 concentrations, (3) these increases can be significantly attenuated by L-carnitine supplementation, and (4) these changes do not appear to be related to changes in VPA concentration.

The molecular basis of O2-sensing and hypoxia tolerance in pheochromocytoma cells.

Hypoxia is a common environmental stimulus. However, very little is known about the mechanisms by which cells sense and respond to changes in oxygen. Our laboratory has utilized the PC12 cell line in order to study the biophysical and molecular response to hypoxia. The current review summarizes our results. We demonstrate that the O2-sensitive K(+) channel, Kv1.2, is present in PC12 cells and plays a critical role in the hypoxia-induced depolarization of PC12 cells. Previous studies have shown that PC12 cells secrete a variety of autocrine/paracrine factors, including dopamine, norepinephrine, and adenosine during hypoxia. We investigated the mechanisms by which adenosine modulates cell function and the effect of chronic hypoxia on this modulation. Finally, we present results identifying the mitogen- and stress-activated protein kinases (MAPKs and SAPKs) as hypoxia-regulated protein kinases. Specifically, we show that p38 and an isoform, p38gamma, are activated by hypoxia. In addition, our results demonstrate that the p42/p44 MAPK protein kinases are activated by hypoxia. We further show that p42/p44 MAPK is critical for the hypoxia-induced transactivation of endothelial PAS-domain protein 1 (EPAS1), a hypoxia-inducible transcription factor. Together, these results provide greater insight into the mechanisms by which cells sense and adapt to hypoxia.

Regulation of CREB by moderate hypoxia in PC12 cells.

The mechanisms by which excitable cells adapt and respond to changes in O2 levels remain largely unknown. We have investigated the effect of hypoxia on the cyclic AMP response element binding protein (CREB) transcription factor. PC12 cells were exposed to moderate levels of hypoxia (5% O2) for various times between 20 min and 6 hr. We found that hypoxia rapidly and persistently induced ser133 phosphorylation of CREB. This effect was more robust than that produced by exposing PC12 cells to either forskolin, KCl, or NGF. This effect was not due to activation of any of the previously known CREB kinases, including PKA, CaMK, PKC, p70s6k, or MAPKAP kinase-2. Thus, hypoxia may induce activation of a novel CREB kinase. To test whether phosphorylation of CREB was associated with an activation of CRE-dependent gene expression, cells were transfected with wild type and mutated regions of the 5'-flanking region of the tyrosine hydroxylase (TH) gene fused to a CAT reporter gene. Mutation of the CRE element in a TH reporter gene reduced, but did not abolish, the effects of hypoxia on TH gene expression. However, hypoxia did not induce transactivation of a GAL4-luciferase reporter by a GAL4-CREB fusion protein. Thus, the mechanism by which hypoxia regulates CREB is distinct, and more complex, than that induced by forskolin, depolarization, or nerve growth factor.

Functional properties of meat by-products and mechanically separated chicken (MSC) in a high-moisture model petfood system.

Contributions to water retention capacity (% WRC) and texture changes were determined for pork by-products (lung lobes, kidneys), chicken viscera (head, feet and viscera) and mechanically separated chicken (MSC) as affected by pH and various salts in a high-moisture model system. The % WRC for meat by-products and MSC was increased by increased pH (4.5-6.8). Pork lungs and MSC had the highest % WRC (p<0.05) among the meat by-products. Meat by-product % WRC was not signifcantly (p>0.05) affected by salt (2%), phosphate (0.3%) or NaOH (0.075%). Chicken viscera had the lowest (p<0.05) mean texture measurements among the meat by-products and MSC. Strong negative correlations (p<0.05) were obtained for texture with total collagen, soluble collagen and high ionic strength soluble (HIS) proteins. These results should be considered for product quality changes when these by-products are used in formulation of high moisture pet food products.

Composition and protein fractions of different meat by-products used for petfood compared with mechanically separated chicken (MSC).

Pork by-products (lung lobes, kidneys), chicken viscera (head, feet and viscera) and mechanically separated chicken (MSC) were evaluated for proximate composition, protein distribution and connective tissue. Proximate composition varied among meat by-products and MSC. Pork by-products contained the most crude protein (p<0.05). Low levels of high ionic strength soluble (HIS) proteins were obtained from meat by-products. Pork lungs and chicken viscera contained the greatest amounts of insoluble (IN) proteins (p<0.05). Total collagen values were positively correlated to IN proteins, intramuscular collagen (IMC) and elastin. Types I and III collagen could not be detected by SDS-PAGE for the different meat by-products though collagen solubility appeared to be significant. These results suggest functional property differences between specific by-products are likely when used in petfood product formulations.

Structural and palatability relationships in frozen ground beef patties as a function of freezing treatments and product formulation.

Four freezing rates for ground beef patties were evaluated for product quality effects and microstructural changes. These rates were further evaluated for different pattie formulations involving post-rigor and pre-rigor meat. Both light microscopy (LM) and scanning electron microscopy (SEM) were utilised for microstructural comparisons. Fast freezing rates had a positive effect on pattie quality, resulting in increased juiciness, tenderness and overall acceptability. Photomicrographs showed increased ice cavity size with decreased freezing rates, which probably contributed to increased cooking shrink and tenderness changes observed. Pre-rigor patties compared very favourably with conventional post-rigor beef patties and showed no obvious structural differences.