A Clinical Comparison of Two Formulations of Tobramycin 0.3% Eyedrops in the Treatment of Acute Bacterial Conjunctivitis

Purpose

To compare the safety and efficacy of a new enhanced viscosity ophthalmic formulation of tobramycin, given twice daily (BID), with the existing four times daily (QID) treatment regimen in patients with acute bacterial conjunctivitis.

Methods

This was a 12-day, multicenter, observer-masked, randomized, parallel group study. Patients received one drop of tobramycin 0.3% (3 mg/mL) enhanced viscosity ophthalmic solution BID or tobramycin 0.3% (3 mg/mL) ophthalmic solution QID in the affected eyes for 7 days. The primary efficacy variable was the percentage of patients with sustained cure/presumed bacterial eradication based on clinical judgment at the test-of-cure visit (Day 12). Pretherapy bacterial isolates were obtained and tested for susceptibility to tobramycin by determination of minimum inhibitory concentrations (MIC).

Results

A total of 276 patients were enrolled in the study and 203 of these were culture positive and attended all follow-up examinations. In this group, 98% of those treated with tobramycin enhanced viscosity ophthalmic solution and 99% of those treated with tobramycin 0.3% ophthalmic solution were categorized as having sustained cure/presumed eradication at the test-of-cure visit (p=0.6037). Reported adverse events were not serious, mild to moderate in severity, and generally did not prevent continuation in the study. Several pretreatment pathogens demonstrated tobramycin resistance (MIC > 4 mg/mL). However, therapy with both treatments was effective in the majority of the cases.

Conclusions

Tobramycin enhanced viscosity ophthalmic solution is well tolerated and has equivalent efficacy to the established treatment regimen with a simplified posology. The formulation provides an alternative therapy for acute bacterial conjunctivitis that should improve patient compliance and satisfaction.

Sorafenib targets BRAF and VEGFR in metastatic thyroid carcinoma

6019

Background. There is no effective therapy for patients with metastatic thyroid cancer not cured by surgery or treatment with I131. Sorafenib is a promising multi-tyrosine kinase inhibitor for patients with metastatic PTC (mPTC). Although the primary targets of sorafenib are thought to include BRAF and VEGFR, this has been the subject of debate. Whether sorafenib primarily acts on the tumor cells (TC) or endothelial cells (EC) and how BRAF mutation status (45% of PTC harbor V600E) relates to response is also unknown. Methods. Responses of patients with metastatic, iodine-refractory PTC, enrolled into our phase II study of sorafenib were monitored by PET at 4 wks and CTs every 2 mos. Sorafenib activity was studied using immunohistochemistry (IHC) for pERK, pAKT, and pVEGFR-2, while Ki-67 showed proliferating cells in tumor tissue pre- and on treatment. BRAF mutation status was determined by DNA sequencing. Results. Of 15 patients, five patients achieved a PR, three are stable (SD), two progressed, and three patients with SD withdrew due to toxicity. Target lesions decreased on average 31%. Eight of 10 PET scans showed decreased activity at 4 weeks. IHC on tissue from 2 patients (at 1 and 2 wks, both BRAFwt) showed 50% decrease in pERK (downstream of VEGFR2 and BRAF) and 30% decrease in pAKT (downstream of VEGFR2). p-ERK and p-AKT were altered in both the TC and EC. Ki-67 decreased from 10% to <1%. No change in VEGFR-2 was seen; but, pVEGFR-2 completely disappeared in one sample while the other showed a small decrease. Quantitative analysis using a multispectral imaging system confirmed the changes observed by IHC. In tissue from a patient at 17 months on sorafenib, the decrease in pERK and pAKT appeared to be the same or reversed, suggesting compensatory changes in these pathways in resistant but stable disease. Conclusions. Our study shows the early clinical and biologic activity of sorafenib in patients with mPTC and the targets of early suppression. Importantly, it also reveals compensatory changes in target molecules in cells resistant to therapy. These cells are the likely source of tumor resistance that has been seen to develop to other similar targeted agents. Sorafenib is the first viable treatment option for patients with mPTC, and these results provide key insights into the mechanisms of action and resistance of this drug.

No significant financial relationships to disclose.

Green tea catechins as brain-permeable, non toxic iron chelators to "iron out iron" from the brain

Evidence to link abnormal metal (iron, copper and zinc) metabolism and handling with Parkinson's and Alzheimer's diseases pathology has frequently been reported. The capacity of free iron to enhance and promote the generation of toxic reactive oxygen radicals has been discussed numerous times. Metal chelation has the potential to prevent iron-induced oxidative stress and aggregation of alpha-synuclein and beta-amyloid peptides. The efficacy of iron chelators depends on their ability to penetrate the subcellular compartments and cellular membranes where iron dependent free radicals are generated. Thus, natural, non-toxic, brain permeable neuroprotective drugs, are preferentially advocated for "ironing out iron" from those brain areas where it preferentially accumulates in neurodegenerative diseases. This review will discuss the most recent findings from in vivo and in vitro studies concerning the transitional metal (iron and copper) chelating property of green tea, and its major polyphenol, (-)-epigallocatechin-3-gallate with respect to their potential for the treatment of neurodegenerative diseases.

The copper chelator, D-penicillamine, does not attenuate MPTP induced dopamine depletion in mice

In MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) and 6-hydroxydopamine induced dopaminergic neurotoxicity and Parkinson's disease iron accumulates in substantia nigra pars compacta which has been suggested to participate in oxidative stress induced neurodegeneration. Pretreatment with iron chelators desferal, clioquinol, VK-28 and M30 are neuroprotective in both models. To determine the specificity of chelation neuroprotective activity we have examined the effect of D-penicillamine, a relatively specific copper chelator, in the mice model of MPTP-induced dopamine depletion. Our studies show that D-penicillamine, employed for removal of copper in Wilson disease is relatively weak in preventing dopaminergic neurotoxicity induced by MPTP, as compared to iron chelators previously studied. The results indicate that for prevention of MPTP-induced dopamine depletion and dopamine neurodegeneration, iron rather than copper chelation may be more effective and specific.

Reduction of iron-regulated amyloid precursor protein and beta-amyloid peptide by (-)-epigallocatechin-3-gallate in cell cultures: implications for iron chelation in Alzheimer's disease

Brain iron dysregulation and its association with amyloid precursor protein (APP) plaque formation are implicated in Alzheimer's disease (AD) pathology and so iron chelation could be considered a rational therapeutic strategy for AD. Here we analyzed the effect of the main polyphenol constituent of green tea, (-)-epigallocatechin-3-gallate (EGCG), which possesses metal-chelating and radical-scavenging properties, on the regulation of the iron metabolism-related proteins APP and transferrin receptor (TfR). EGCG exhibited potent iron-chelating activity comparable to that of the prototype iron chelator desferrioxamine, and dose dependently (1-10 microm) increased TfR protein and mRNA levels in human SH-SY5Y neuroblastoma cells. Both the immature and full-length cellular holo-APP were significantly reduced by EGCG, as shown by two-dimensional gel electrophoresis, without altering APP mRNA levels, suggesting a post-transcriptional action. Indeed, EGCG suppressed the translation of a luciferase reporter gene fused to the APP mRNA 5'-untranslated region, encompassing the APP iron-responsive element. The finding that Fe(2)SO(4) reversed the action of EGCG on APP and TfR proteins reinforces the likelihood that these effects are mediated through modulation of the intracellular iron pool. Furthermore, EGCG reduced toxic beta-amyloid peptide generation in Chinese hamster ovary cells overexpressing the APP 'Swedish' mutation. Thus, the natural non-toxic brain-permeable EGCG may provide a potential therapeutic approach for AD and other iron-associated disorders.

Involvement of multiple survival signal transduction pathways in the neuroprotective, neurorescue and APP processing activity of rasagiline and its propargyl moiety

Our recent studies aimed to elucidate the molecular and biochemical mechanism of actions of the novel anti-Parkinson's drug, rasagiline, an irreversible and selective monoamine oxidase (MAO)-B inhibitor and its propargyl moiety, propargylamine. In cell death models induced by serum withdrawal in rat PC12 cells and human SH-SY5Y neuroblastoma cells, both rasagiline and propargylamine exerted neuroprotective and neurorescue activities via multiple survival pathways, including: stimulation of protein kinase C (PKC) phosphorylation; up-regulation of protein and gene levels of PKCalpha, PKCepsilon and the anti-apoptotic Bcl-2, Bcl-xL, and Bcl-w; and up-regulation of the neurotrophic factors, BDNF and GDNF mRNAs. Rasagiline and propargylamine inhibited the cleavage and subsequent activation of pro-caspase-3 and poly ADP-ribose polymerase. Additionally, these compounds significantly down-regulated PKCgamma mRNA and decreased the level of the pro-apoptotic proteins, Bax, Bad, Bim and H2A.X. Rasagiline and propargylamine both regulated amyloid precursor protein (APP) processing towards the non-amyloidogenic pathway. These structure-activity studies have provided evidence that propargylamine promoted neuronal survival via neuroprotective/neurorescue pathways similar to that of rasagiline. In addition, recent study demonstrated that chronic low doses of rasagiline administered to mice subsequently to 1 methyl-4 phenyl 1,2,3,6 tetrahydropyridine (MPTP), rescued dopaminergic neurons in the substantia nigra pars compacta via activation of the Ras-PI3K-Akt survival pathway, suggesting that rasagiline may possess a disease modifying activity.

Green tea polyphenol (-)-epigallocatechin-3-gallate induces neurorescue of long-term serum-deprived PC12 cells and promotes neurite outgrowth

Our previous studies have shown that the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) prevents neuronal cell death caused by several neurotoxins. The present study sought to determine the neuroprotective effect of EGCG when it is administered after the induction of cell damage ('neurorescue'). In an attempt to imitate a progressive mode of death, PC12 cells were initially subjected to serum-starvation conditions for a period of 1 or 3 days before administration of EGCG (0.1-10 microM) for up to 3 days. In spite of the high percentage of cell death, single or repetitive administration of EGCG (1 microM) significantly attenuated cell death. The neurorescue effect of EGCG was abolished by pre-treatment with the protein kinase C inhibitor GF109203X (2.5 microM), suggesting the involvement of the protein kinase C pathway in neurorescue by the drug. This is consistent with the rapid (15 min) translocation of the protein kinase C alpha isoform to the cell membrane in response to EGCG. The correlative neurite outgrowth activity of EGCG on PC12 cells may also contribute to its neurorescue effect. The present findings suggest that EGCG may have a positive impact on aging and neurodegenerative diseases to retard or perhaps even reverse the accelerated rate of neuronal degeneration.

Genome-wide linkage scans for prediabetes phenotypes in response to 20 weeks of endurance exercise training in non-diabetic whites and blacks: the HERITAGE Family Study

AIMS/HYPOTHESIS

Impaired insulin secretion, insulin action, insulin-independent glucose effectiveness, glucose tolerance and the associated abnormalities in insulin and glucose metabolism phenotypes are precursors of type 2 diabetes. Genome-wide multipoint variance component linkage scans were carried out using 654 markers to identify quantitative trait loci for insulin sensitivity, acute insulin response to glucose, disposition index and glucose effectiveness training responses in whites and blacks in the HERITAGE Family Study.

METHODS

These phenotypes were obtained from an IVGTT with the minimal model. The distributions of insulin sensitivity, acute insulin response to glucose and disposition index training responses (post-training minus baseline) were approximately normalised using a square-root transformation. All phenotypes were adjusted for the effects of age, BMI and their respective baseline values within sex and generation by race prior to linkage scans.

RESULTS

In blacks, a promising linkage with a maximum lod score of 3.1 on 19q (54-62 Mb) for glucose effectiveness training response was found. Six interesting linkages with lod scores of at least 1.0 were found for disposition index training response in whites. They included 1p (30 Mb), 3q (152 Mb), 6p (23-42 Mb), 7q (95-96 Mb), 10p (15 Mb) and 12q (119-126 Mb).

CONCLUSIONS/INTERPRETATION

Quantitative trait loci for 20 weeks of endurance exercise training responses in insulin action and glucose metabolism phenotypes were found on chromosome 19q as well as 6p and 7q, with nominal (6p, 7q) but consistent (6p) linkages across the races.

Placental protein 13 (PP-13): effects on cultured trophoblasts, and its detection in human body fluids in normal and pathological pregnancies

Placental tissue protein 13 (PP-13), one of the 56 known placental proteins identified till today, was purified from placentas obtained from women at delivery, and used to evoke antibodies against it. The purified PP-13 was lysed to peptides, which were sequenced, leading to the full-length cDNA sequencing and its expression in Escherichia coli. Sequence analysis in databases showed homology to the galectin family. Of the various antibody preparations developed, a pair of monoclonal antibodies (MAbs) coupled to the recombinant PP-13 (PP-13-R) was used for the immunodetection of PP-13 in pregnant women's serum with the solid-phase ELISA format. With a dynamic range of 25-500 pg/mL with no background in non-pregnant women's serum and men's serum, the ELISA test was suitable for the detection of PP-13 in the 1st, 2nd, and 3rd trimesters. PP-13 levels slowly increase during pregnancy. In the 1st trimester, lower than normal PP-13 levels were found in fetal growth restriction (IUGR), preeclampsia (PE), and particularly in early PE (<34 weeks of gestation). In the 2nd and 3rd trimesters, higher than normal concentrations were found in PE, IUGR and in preterm delivery (PTD). Application of PP-13 to cultured trophoblasts elicited depolarization carried by calcium ions, followed by liberation of linoleic and arachidonic acids from the trophoblast membrane, and a subsequent elevation of prostacyclin and thromboxane. These effects were negligible when PP-13 derived from the placentas of patients with IUGR, PE or PTD was used. The results are discussed in view of the potential utilization of PP-13 for early serum screening to assess the risk to develop placental insufficiency, coupled to a differential analysis of the various pathologies by analyzing cultured trophoblasts.

Gene expression profiling of parkinsonian substantia nigra pars compacta; alterations in ubiquitin-proteasome, heat shock protein, iron and oxidative stress regulated proteins, cell adhesion/cellular matrix and vesicle trafficking genes

Gene expression profiling of human substantia nigra pars compacta (SNpc) from Parkinson's disease (PD) patients, was examined employing high density microarrays. We identified alterations in the expression of 137 genes, with 68 down regulated and 69 up regulated. The down regulated genes belong to signal transduction, protein degradation (e.g. ubiquitin-proteasome subunits), dopaminergic transmission/metabolism, ion transport, protein modification/phosphorylation and energy pathways/glycolysis functional classes. Up-regulated genes, clustered mainly in biological processes involving cell adhesion/cytoskeleton, extracellular matrix components, cell cycle, protein modification/phosphorylation, protein metabolism, transcription and inflammation/stress (e.g. key iron and oxygen sensor EGLN1). One major finding in the present study is the particular decreased expression of SKP1A, a member of the SCF (E3) ligase complex specifically in the substantia nigra (SN) of sporadic parkinsonian patients, which may lead to a wide impairment in the function of an entire repertoire of proteins subjected to regulatory ubiquitination. These findings reveal novel players in the neurodegenerative scenario and provide potential targets for the development of novel drug compounds.

Inclusion body myositis in connective tissue disorders: case report and review of the literature

We report a patient with systemic lupus erythematosus (SLE) and secondary Sjögren's syndrome (SS) who developed inclusion body myositis (IBM) which, contrary to the typical presentation of this disorder, was symmetrical in nature although the diagnosis was only made after electron microscopy was performed. Therapy with increased doses of methotrexate proved to be beneficial, with the patient having full recovery after 8 months of therapy. It appears that a subset of IBM may be related to autoimmune disorders, an issue that was disputed in the past, and these patients may have a better prognosis than typical IBM patients. This is the first case report of IBM in a patient who had the dual diagnosis of SLE and SS.

The use of laparoscopy in abdominal emergencies

BACKGROUND

The purpose of this article is to describe our experience using laparoscopy in the management of emergent and acute abdominal conditions.

METHODS

Between March 1997 and November 2001, 277 consecutive minimally invasive procedures were performed for various nontrauma surgical emergencies. The indications for operation were nonspecific abdominal pain in 129 cases (46%), peritonitis in 64 cases (23%), small bowel obstruction in 52 cases (19%), complications after previous surgery or invasive procedures in 24 cases (9%), and sepsis of unknown origin in 8 cases (3%).

RESULTS

Laparoscopy obtained a correct diagnosis in 98.6% of the cases. In 207 patients (75%), the procedure was completed laparoscopically. An additional 35 patients (12.5%) required a target incision. The remaining 35 patients (12.5%) underwent formal laparotomy. The morbidity rate was 5.8%. No laparoscopy-related mortality was observed.

CONCLUSIONS

For patients with abdominal emergencies, the laparoscopic approach provides diagnostic accuracy and therapeutic options, avoids extensive preoperative studies, averts delays in operative intervention, and appears to reduce morbidity.

Which plasma antioxidants are most related to fruit and vegetable consumption?

Substantial evidence suggests that fruit and vegetable intake reduces the risk of some cancers and other chronic diseases. While a varied diet containing fruits and vegetables may confer benefits greater than those of any single nutrient, it would be useful to have data on the plasma nutrients most influenced by fruit and vegetable intake. The authors examined the correlation between fruit and vegetable intake as measured by the abbreviated CLUE II food frequency questionnaire and several plasma antioxidants. This study includes 116 male subjects aged 35-72 years who were nonsmokers and nonusers of vitamin supplements and who provided blood samples in the CLUE II Study in Washington County, Maryland. Plasma was assayed for ascorbic acid, beta-carotene, beta-cryptoxanthin, and alpha- and gamma-tocopherol. Lipid- and energy-adjusted partial correlation for the relation with fruit and vegetable intake was r = 0.64 for ascorbic acid, r = 0.44 for beta-carotene, and r = 0.50 for beta-cryptoxanthin. While this study does not address efficacy, the stronger association of ascorbic acid with fruit and vegetable intake seen here may imply that ascorbic acid is an important component of the protective effect seen for fruits and vegetables in numerous epidemiologic studies.

Green tea polyphenol (-)-epigallocatechin-3-gallate prevents N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopaminergic neurodegeneration

In the present study we demonstrate neuroprotective property of green tea extract and (-)-epigallocatechin-3-gallate in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mice model of Parkinson's disease. N-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxin caused dopamine neuron loss in substantia nigra concomitant with a depletion in striatal dopamine and tyrosine hydroxylase protein levels. Pretreatment of mice with either green tea extract (0.5 and 1 mg/kg) or (-)-epigallocatechin-3-gallate (2 and 10 mg/kg) prevented these effects. In addition, the neurotoxin caused an elevation in striatal antioxidant enzymes superoxide dismutase (240%) and catalase (165%) activities, both effects being prevented by (-)-epigallocatechin-3-gallate. (-)-Epigallocatechin-3-gallate itself also increased the activities of both enzymes in the brain. The neuroprotective effects are not likely to be caused by inhibition of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine conversion to its active metabolite 1-methyl-4-phenylpyridinium by monoamine oxidase-B, as both green tea and (-)-epigallocatechin-3-gallate are very poor inhibitors of this enzyme in vitro (770 microg/mL and 660 microM, respectively). Brain penetrating property of polyphenols, as well as their antioxidant and iron-chelating properties may make such compounds an important class of drugs to be developed for treatment of neurodegenerative diseases where oxidative stress has been implicated.

Gene expression analysis in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mice model of Parkinson's disease using cDNA microarray: effect of R-apomorphine

To establish the possible roles of oxidative stress, inflammatory processes and other unknown mechanisms in neurodegeneration, we investigated brain gene alterations in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice model of Parkinson's disease using Atlas mouse cDNA expression array membrane. The expression of 51 different genes involved in oxidative stress, inflammation, glutamate and neurotrophic factors pathways as well as in still undefined processes, such as cell cycle regulators and signal transduction molecules, was differentially affected by the treatment. The present study indicates the involvement of an additional cascade of events that might act in parallel to oxidative stress and inflammation to converge eventually into a common pathway leading to neurodegeneration. The attenuation of these gene changes by R-apomorphine, an iron chelator-radical scavenger drug, supports our previous findings in vivo where R-apomorphine was neuroprotective.

Laryngeal manifestations of postpoliomyelitis syndrome

Postpoliomyelitis syndrome (PPS) is a disease that may occur in survivors of acute poliomyelitis several decades after their initial infection. It can present as dysphonia, with vocal weakness and fatigue. Swallowing, respiratory, and other laryngopharyngeal symptoms may be manifestations of the disease or they may represent worsening of previously stable and compensated deficits. Three cases of laryngeal changes in PPS with videostroboscopic and laryngeal electromyography findings highlight the features of this disorder. We review possible etiologies of laryngeal PPS, diagnostic criteria, and treatment, as well as the current literature.

cDNA microarray to study gene expression of dopaminergic neurodegeneration and neuroprotection in MPTP and 6-hydroxydopamine models: implications for idiopathic Parkinson's disease

cDNA microarray membranes comprising 1,200 different gene fragments have been employed to identify gene expression profile in MPTP-induced nigro striatal dopamine neurodegeneration and its protection with Rapomorphine. Both MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) and R-apomorphine (R-APO) induced alterations in specific patterns of gene expression. MPTP altered the expression of 49 different genes involved in oxidative stress (oxidative stress-induced protein A 170, cytochrome P450 1A1 and Osp94), inflammation (cytotoxic cytokines, eg: IL-1, IL-6, TNF-alpha), protective cytokines (IL-10), glutamate receptors (NMDA but not AMPA receptors), neurotrophic factors (GDNF, EGF), nitric oxide synthase and transferrin receptor, as determined by microarray membrane hybridization. Furthermore, an additional cascade of further, yet undefined events, also occurred (cell cycle regulators and signal transduction factors), that might act in parallel to oxidative stress (OS) and inflammation, to converge eventually into a common pathway leading to neurodegeneration. R-APO, previously shown by us to protect against MPTP neurotoxicity, prevented the over expression of several genes known to participate in cell death. cDNA microarrays will provide new prospects to study and identify various mechanism of neurodegeneration and neuroprotection not feasible with conventional biochemical procedures, as well as new prospects to develop effective neuroprotective drugs.

Effects of R- and S-apomorphine on MPTP-induced nigro-striatal dopamine neuronal loss

In order to establish whether the antioxidant and iron-chelating activities of R-apomorphine (R-APO), a D(1)-D(2) receptor agonist, may contribute to its neuroprotective property, its S-isomer, which is not a dopamine agonist, was studied. The neuroprotective property of R- and S-APO has been studied in the MPTP model of Parkinson's disease (PD). Both S-APO (0.5-1 mg/kg, subcutaneous) and R-APO (10 mg/kg) pretreatment of C57-BL mice, protected against MPTP (24 mg/kg, intraperitoneally) induced dopamine (DA) depletion and reduction in tyrosine hydroxylase (TH) activity. However, only R-APO prevented nigro-striatal neuronal cell degeneration, as indicated by the immunohistochemistry of TH positive neurones in substantia nigra and by western analysis of striatal TH content. R-APO prevented the reduction of striatal-GSH and the increase in the ratio of GSSG over total glutathione, caused by MPTP treatment. In vitro both R-APO and S-APO inhibited monoamine oxidase A and B activity at relatively high concentrations (100 and 300 micromol/L, respectively). The elevated activity of TH induced by the two enantiomers may contribute to the maintenance of normal DA levels, suggesting that one of the targets of these molecules may involve upregulation of TH activity. It is suggested that the antioxidant and iron-chelating properties, possible monoamine oxidase inhibitory actions, together with activation of DA receptors, may participate in the mechanism of neuroprotection by APO enantiomers against MPTP.

Combined tall cell carcinoma and Hürthle cell carcinoma (collision tumor) of the thyroid

Tall cell carcinoma and Hürthle cell carcinoma are 2 aggressive forms of differentiated follicular-derived thyroid carcinomas. We present a case where these malignant tumors of thyroid coexisted. The tumor originated in the thyroid as a mixed tumor and metastasized as a tall cell tumor to the lymph nodes and as a Hürthle cell carcinoma to lungs. The coexistence of these tumor types is rare and sheds light on the histogenesis of Hürthle cell tumors and the metastatic behavior of combined tumors.

Iron chelating, antioxidant and cytoprotective properties of dopamine receptor agonist; apomorphine

There have been many attempts to discover neuroprotective drugs for the treatment of Parkinson's disease (PD). Many of these compounds either do not cross the blood brain barrier or are not very effective in the 6-hydroxydopamine or MPTP (N-methyl-4-phenyl-1,2,3,6-terahydropyridine) models of PD. We have examined several compounds including dopamine receptor agonist bromocritine, lisuride, pergolide and R-apomorphine for their neuroprotective action against the above neurotoxins in PC12 and dopamine neuroblastoma cell lines in culture and in vivo. R-apomorphine exhibited relatively potent neuroprotective action in vitro, cell culture and in vivo as a radical scavenger and iron chelator, because of its catechol structure. The recent clinical trials with apomorphine, where parkinsonian subjects can be weaned off L-dopa would suggest that this drug either exerts a neuroprotective action or that continuous sustained stimulation of dopamine receptor may be responsible for its unusual pharmacological activity. Apomorphine has a far more broad neuroprotective activity in the various models as compared with 1-selegiline and may therefore be an ideal drug to study neuroprotection in parkinsonian subjects with the use of PET or SPECT.

Laryngeal Myasthenia Gravis: Report of 40 Cases

Myasthenia gravis, an autoimmune disorder of the neuromuscular junction, is usually recognized because of ocular complaints or generalized weakness. We report a series of 40 patients who presented with dysphonia as their initial and primary complaint. Diagnostic testing included strobovideolaryngoscopy, electromyography (EMG) with repetitive stimulation and Tensilon testing, and laboratory and radiographic evaluation. Strobovideolaryngoscopy most commonly revealed fluctuating impairment of vocal fold mobility, either unilateral or bilateral. EMG detected evidence of neuromuscular junction abnormalities in all patients. Only one patient had evidence of antiacetylcholine receptor (ACh-R) antibodies, but many other abnormalities suggestive of autoimmune dysfunction were present. Pyridostigmine therapy was initiated in 34 patients but was not tolerated in 4. Of the remaining 30 patients, 23 reported improvement of symptoms. We conclude that myasthenia gravis can present with symptoms confined primarily to the larynx and should be included in the differential diagnosis of dysphonia.

Diagnosis of primary HIV-1 infection. Los Angeles County Primary HIV Infection Recruitment Network

BACKGROUND

The optimal approach for diagnosing primary HIV-1 infection has not been defined.

OBJECTIVE

To determine the usefulness of symptoms and virologic tests for diagnosing primary HIV-1 infection.

DESIGN

Prospective cohort study.

SETTING

A teaching hospital in Los Angeles and a university research center in San Diego, California.

PATIENTS

436 patients who had symptoms consistent with primary HIV infection.

MEASUREMENTS

Clinical information and levels of HIV antibody, HIV RNA, and p24 antigen.

RESULTS

Primary infection was diagnosed in 54 patients (12.4%). The sensitivity and specificity of the p24 antigen assay were 88.7% (95% CI, 77.0% to 95.7%) and 100% (CI, 99.3% to 100%), respectively. For the HIV RNA assay, sensitivity was 100% and specificity was 97.4% (CI, 94.9% to 98.9%). Fever, myalgia, rash, night sweats, and arthralgia occurred more frequently in patients with primary infection (P < 0.05).

CONCLUSIONS

No sign or symptom allows targeted screening for primary infection. Although assays for HIV RNA are more sensitive than those for p24 antigen in diagnosing primary infection, they are more expensive and are more likely to yield false-positive results.

Heart rate and blood pressure changes with endurance training: the HERITAGE Family Study

PURPOSE

The purpose of this study was to determine the magnitude of change in resting and exercise heart rate (HR) and blood pressure (BP), by race, sex, and age, after a 20-wk endurance training program in 507 healthy and previously sedentary subjects from the HERITAGE Family Study.

METHODS

After baseline measurements, subjects exercised on cycle ergometers 3 d x wk(-1) for a total of 60 exercise sessions starting at 55% of VO2max for 30 min x session(-1) and building to 75% of VO2max for 50 min x session(-1) for the last 6 wk. HR and BP at rest and during exercise (50 W, 60% of VO2max maximal exercise) were each determined in duplicate on two different days both before and after training (resting values at 24-h and 72-h posttraining).

RESULTS

After the period of training, there was a small decrease in resting HR (-2.7 to -4.6 beats x min(-1) across groups at 72-h posttraining), and small changes (i.e., < 3 mm Hg) in resting systolic (SBP), diastolic (DBP), and calculated mean BP (MBP), which varied by race, sex, and age. During exercise at the same absolute work rate (50 W), HR, SBP, DBP, and MBP were all significantly reduced, with greater reductions in HR in women compared with men, and greater reductions in BP in blacks and older subjects compared with whites and younger subjects, respectively. At the same relative work rate (60% VO2max), HR, DBP, and MBP were reduced, but SBP remained unchanged. Blacks had a greater reduction in DBP, but whites had a greater reduction in HR. Finally, at maximal exercise, there was a small decrease in HR, with men and whites decreasing more than women and blacks; an 8 mm Hg increase in SBP, with men increasing more than women; a 4 mm Hg decrease in DBP, with blacks decreasing more than whites; and no change in MBP.

CONCLUSION

In conclusion, the reductions in resting HR and BP with training were generally small, but the reductions during exercise were substantial and clinically important, with the older and the black populations experiencing greater reductions.

Cardiac output and stroke volume changes with endurance training: the HERITAGE Family Study

PURPOSE

The purpose of this study was to determine the magnitude of changes in cardiac output (Qc), stroke volume (SV), and arterial-mixed venous oxygen difference (a-vO2 diff) during submaximal exercise following a 20-wk endurance training program, with the primary focus on identifying differences in response by race, sex, and age.

METHODS

The participants in this study (N = 631) were healthy and previously sedentary men (N = 277) and women (N = 354) of varying age (17-65 yr) and race (blacks, N = 217; whites, N = 414) who had completed the HERITAGE Family Study protocol. After baseline measurements, participants trained on cycle ergometers 3 d x wk(-1) for a total of 60 exercise sessions starting at the HR associated with 55% of maximal oxygen uptake (VO2max) for 30 min/session and building to the HR associated with 75% of VO2max for 50 min/session, which was maintained during the last 6 wk. HR, Qc (CO2 rebreathing), and SV (Qc/HR) were determined in duplicate at 50 W and at 60% of VO2max on two different days both before and after training.

RESULTS

After training, there were significant decreases in HR and Qc, and significant increases in SV and a-vO2 diff at 50 W (except for no change in a-vO2 diff in black men). The changes in HR differed by sex and age, and the changes in SV, Qc, and a-vO2 diff differed by race. Qc decreased by 0.6 L x min(-1) at 50 W for the total sample, consistent with the decrease in VO2 at this power output. At 60% of VO2max HR decreased, and SV, Q, and a-VO2 diff increased. There were small differences in response by sex (HR and SV), race (HR), and age (HR and Qc).

CONCLUSION

It is concluded that the cardiovascular systems of men and women, blacks and whites, and younger and older subjects are not limited in their ability to adapt to endurance training.

Ultrasound-guided fine-needle aspiration biopsy of the thyroid: role of on-site assessment and multiple cytologic preparations

Several studies have shown that ultrasound guidance can serve as a valuable aid in improving the diagnostic yield of fine-needle aspiration (FNA) biopsy of thyroid nodules. In this study, we evaluated the combined impact of ultrasound-guidance, rapid on-site evaluation of FNA specimens, and different cytologic preparations (fresh and alcohol-fixed smears, Millipore filter) and staining methods (Diff-Quik and Papanicolaou stains) on the diagnostic yield of thyroid FNA. Ultrasound-guided FNA was performed on 282 patients (313 cases) between November 1997 and April 1999. The diagnostic categories included: benign (198 cases, 63.2%); indeterminate (42 cases, 13.4%); suspicious for follicular variant of papillary carcinoma (26 cases, 8.3%), malignant (32 cases, 10.1%); and nondiagnostic (15 cases, 5%). The nondiagnostic cases also included 6 cystic lesions without any solid component and 3 thyroid-bed aspirations. After excluding these, the nondiagnostic rate was only 2%. Histological follow-up was available in 77 (77/313) cases. The concordance rate between cytological and histological diagnosis was 100% in malignant, 67% in suspicious, and 56% in indeterminate cases. All cases with histologic follow-up were selected to evaluate the independent diagnostic efficacy of each aforementioned cytologic staining method. A definite diagnosis could be made solely on the basis of air-dried, Diff-Quik-stained preparations in 50 (65%), alcohol-fixed, Papanicolaou stained smears in 68 (88%), and Millipore filter preparations in 70 (91%) cases. We conclude that ultrasound-guided FNA combined with on-site evaluation and different cytologic preparations can significantly improve the diagnostic accuracy of thyroid FNA specimens.

Thyroid nodules with FNA cytology suspicious for follicular variant of papillary thyroid carcinoma: follow-up and management

Thyroid nodules diagnosed as follicular neoplasm on fine-needle aspiration biopsy (FNAB) may represent hyperplastic/adenomatous nodules, follicular adenoma or carcinoma, and follicular variants of papillary thyroid carcinoma (FVPTC) on histologic follow-up. In our laboratory, we attempted to identify a subset of cases which showed cellular specimens with focal features (nuclear chromatin clearing, membrane thickening, and rare grooves) suspicious for the follicular variant of papillary thyroid carcinoma. These cases are reported as follicular-derived neoplasms with nuclear features suspicious for FVPTC to distinguish them from those diagnosed as follicular neoplasm. This study documents our experience with 52 cases so diagnosed and followed prospectively with histologic follow-up. A neoplastic nodule was confirmed in 45/52 cases (86%), of which 40 were malignant (77%). FVPTC was identified in 35/52 cases (67%). Four cases were usual papillary carcinoma, 3 were follicular adenoma, 2 were Hürthle-cell adenoma, and 1 was insular carcinoma. In 7 cases, the subsequent histologic findings were nonneoplastic (5 hyperplastic nodules and 2 colloid nodules). Our prospective study shows that in cellular smears from thyroid nodules, a careful search for the nuclear features of papillary carcinoma should be performed, and it is appropriate to diagnose cases as suspicious for FVPTC if the nuclear features of papillary carcinoma are focal. The surgical management of this group may include an intraoperative confirmation of cytologic diagnosis by scrape preparation and/or frozen section in order to avoid a second surgical intervention for completion thyroidectomy.

Neuroprotective strategies in Parkinson's disease using the models of 6-hydroxydopamine and MPTP

The etiology of Parkinson's disease is not known. Nevertheless a significant body of biochemical data from human brain autopsy studies and those from animal models point to an on going process of oxidative stress in the substantia nigra which could initiate dopaminergic neurodegeneration. It is not known whether oxidative stress is a primary or secondary event. Nevertheless, oxidative stress as induced by neurotoxins 6-hydroxydopamine and MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) has been used in animal models to investigate the process of neurodegeneration with intend to develop antioxidant neuroprotective drugs. It is apparent that in these animal models radical scavengers, iron chelators, dopamine agonists, nitric oxide synthase inhibitors and certain calcium channel antagonists do induce neuroprotection against such toxins if given prior to the insult. Furthermore, recent work from human and animal studies has provided also evidence for an inflammatory process. This expresses itself by proliferation of activated microglia in the substantia nigra, activation and translocation of transcription factors, NF kappa-beta and elevation of cytotoxic cytokines TNF alpha, IL1-beta, and IL6. Both radical scavengers and iron chelators prevent LPS (lipopolysaccharide) and iron induced activation of NF kappa-B. If an inflammatory response is involved in Parkinson's disease it would be logical to consider antioxidants and the newly developed non-steroid anti-inflammatory drugs such as COX2 (cyclo-oxygenase) inhibitors as a form of treatment. However to date there has been little or no success in the clinical treatment of neurodegenerative diseases per se (Parkinson's disease, ischemia etc.), where neurons die, while in animal models the same drugs produce neuroprotection. This may indicate that either the animal models employed are not reflective of the events in neurodegenerative diseases or that because neuronal death involves a cascade of events, a single neuroprotective drug would not be effective. Thus, consideration should be given to multi-neuroprotective drug therapy in Parkinson's disease, similar to the approach taken in AIDS and cancer therapy.

An interactive CD-ROM for nutrition screening and counseling

OBJECTIVES

The goal of this project was to develop an interactive CD-ROM for nutrition screening and counseling, designed to produce dietary behavior change in fat and fruit and vegetable intake.

METHODS

The design was based on principles of relevance to the learner, readiness for change, feedback, individualization, facilitation of skills, and goal setting. It was tested in community settings such as libraries, senior centers, and Women, Infants, and Children clinics.

RESULTS

Nearly 80% of the respondents (n = 284), including numerous low-income persons, reported learning something new about nutrition and health or their own dietary habits. More than 50% of those recontacted 2 to 4 weeks later had put some of their dietary goals into practice.

CONCLUSIONS

This program is useful for dietary screening, feedback, skill building, and motivation in settings in which in-person counseling by nutrition professionals is not feasible.

MPTP and 6-hydroxydopamine-induced neurodegeneration as models for Parkinson's disease: neuroprotective strategies

The etiology of Parkinson's disease is not known. Nevertheless, a significant body of biochemical data from human brain autopsy studies and from animal models points to an ongoing process of oxidative stress in the substantia nigra, which could initiate dopaminergic neurodegeneration. It is not known whether oxidative stress is a primary or secondary event. Oxidative stress, as induced by the neurotoxins 6-hydroxydopamine and MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), has been used in animal models to investigate the process of neurodegeneration to facilitate the development of antioxidant, neuroprotective drugs. It is apparent in these animal models that radical scavengers, iron chelators, dopamine agonists, nitric oxide synthase inhibitors and certain calcium channel antagonists provide neuroprotection against such toxins if given prior to the insult. Furthermore, recent work from human and animal studies has provided evidence of an inflammatory process. This expresses itself as proliferation of activated microglia in the substantia nigra, activation and translocation of transcription factors and neurotrophic factor (NF), kappa-beta and elevation of cytotoxic cytokines, tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6. Both radical scavengers and iron chelators prevent lipopolysaccharide (LPS) and iron-induced activation of NF kappa-beta. If an inflammatory response is involved in Parkinson's disease, it would be logical to consider antioxidants and the newly developed, non-steroidal, anti-inflammatory drugs such as cyclo-oxygenase (COX2) inhibitors as a form of treatment. However, to date there has been little or no success in the clinical treatment of neurodegenerative diseases (for example, Parkinson's disease, ischaemia etc.) where neurons die, while in animal models the same drugs provide neuroprotection. This may indicate that either the animal models employed do not reflect the events in neurodegenerative diseases, or that because neuronal death involves a cascade of events, a single neuroprotective drug is not effective. Thus, consideration should be given to multi-neuroprotective drug therapy in Parkinson's disease, similar to the approach taken in AIDS and cancer therapy.

Blood lipid response to 20 weeks of supervised exercise in a large biracial population: the HERITAGE Family Study

We studied the effects of 20 weeks of supervised cycle-ergometer exercise on plasma lipids in 675 healthy, sedentary, normolipidemic white and black men and women aged 17 to 65 years, participating in the HERITAGE Family Study. Fasting plasma lipids were assessed twice at baseline and 24 and 72 hours after the last exercise session and adjusted for plasma volume changes. No significant differences from the mean baseline levels were observed for total, low-density lipoprotein (LDL), and very-low-density lipoprotein (VLDL) cholesterol and apolipoprotein B (Apo B). A significant reduction (P < .01) from baseline levels in plasma total and VLDL triglycerides was observed only in the 24-hour posttraining specimens, reflecting a response to the last bout of exercise. High-density lipoprotein (HDL) cholesterol increased 3.6% for the combined group, primarily due to an increase in HDL2, with an associated increase in Apo A-1 (P < .001). No significant differences were noted in the HDL response by sex, race, or age. An inverse correlation (r = -.241) was observed between the increase in HDL cholesterol and change in body fat only in men, and the increase in HDL cholesterol was unrelated to the change in maximal oxygen uptake (VO2max).

The pivotal role of iron in NF-kappa B activation and nigrostriatal dopaminergic neurodegeneration. Prospects for neuroprotection in Parkinson's disease with iron chelators

R-Apomorphine (APO) the catechol-derived dopamine D1-D2 receptor agonist has been shown to be highly potent iron chelator and radical scavenger and inhibitor of membrane lipid peroxidation in vitro, in vivo and in cell culture employing PC12 cells. Its potency has been compared to the prototype iron chelator desferrioxamine (desferal), dopamine, nifedipine and dopamine D2 receptor agonists, bromocriptine, lisuride, pergolide and pramipexole. APO also inhibits brain and mitochondrial protein oxidation. In vivo APO protects against MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)- induced striatal dopaminergic neurodegeneration in C57 black mice with as low as 5 mg/kg. APO is a reversible competitive inhibitor of monoamine oxidase (MAO) A and B with IC50 values of 93 and 214 uM, respectively. The iron chelating and radical scavenging actions of desferal and APO explains their ability to inhibit iron and 6-hydroxydopamine (6-OHDA)-induced neurodegeneration and activation of redox-sensitive transcription factor NF-kappa B and the subsequent transactivation of promoters of genes involved in inflammatory cytokines. Iron is thought to play a pivotal role in neurodegeneration, and APO may be an ideal drug to investigate neuroprotection in Parkinson's disease where iron and oxidative stress have been implicated in the pathogenesis of nigrostriatal dopamine neuron degeneration.

Thyroid sclerosing mucoepidermoid carcinoma with eosinophilia: mimic of Hodgkin disease in nodal metastases

We present the clinical and pathologic findings of a case of sclerosing mucoepidermoid carcinoma with eosinophilia of the thyroid in a 39-year-old woman. This particular case is notable because it initially presented as a cervical lymph node metastasis, and the initial clinical and histologic impression was Hodgkin disease, nodular sclerosis type. Sclerosing mucoepidermoid carcinoma with eosinophilia is a differentiated malignant neoplasm of the thyroid that can be confused with anaplastic carcinoma, medullary carcinoma, squamous cell carcinoma, or, as in this case, Hodgkin disease. A correct diagnosis of sclerosing mucoepidermoid carcinoma with eosinophilia involves awareness of this entity and appropriate immunohistochemical analysis. In this article, we briefly review the literature and stress the histologic and cytologic findings characteristic of sclerosing mucoepidermoid with eosinophilia of the thyroid.

Virilising 21-hydroxylase deficiency: timing of newborn screening and confirmatory tests can be crucial

Early diagnosis of congenital adrenal hyperplasia (CAH) can be lifesaving. With the advent of newborn screening programs employing blood 17-hydroxyprogesterone, fewer cases are missed. Because false positive results occur, especially in premature and low birth weight babies, infants with borderline elevations, although requiring follow-up, are often considered normal. We describe a newborn female that, despite severe virilization, only had a borderline elevation in 17-hydroxyprogesterone (17OHP) on newborn screening, as well as on initial confirmatory testing in our clinical laboratory. Our confirmatory method, which employs high performance liquid chromatography (HPLC) separation, because of its high specificity, yields steroid values from both normal children and those with CAH that are lower than found with older, less specific methods. Given the heterogeneity of phenotypes of CAH, less severe forms, especially in males, could result in marginally abnormal laboratory results early in life, with possible adverse effects later. Although in retrospect the diagnosis of the described patient was clear and not a novel entity, we consider it an important example for several reasons. It emphasizes the broad range of 17OHP levels in CAH, the lack of correlation of these levels with clinical phenotype and the importance of the timing of both screening and confirmatory tests. Due to the complexity of interpreting these tests, any screening program for CAH should be controlled by an experienced pediatric endocrinologist.

Alterations in body weight and composition consequent to 20 wk of endurance training: the HERITAGE Family Study

BACKGROUND

Obesity is a major public health problem in the United States. The role of physical activity and formal exercise in controlling body weight has not been clearly determined.

OBJECTIVE

This study determined the magnitude of change in body weight and composition across sex, race, and age in response to 20 wk of endurance training.

DESIGN

Men and women (n = 557) of various ages (16-65 y) and 2 races (black and white) exercised on cycle ergometers 3 d/wk for a total of 60 exercise sessions starting at 55% of maximal oxygen consumption (VO(2)max) for 30 min/session and building to 75% of VO(2)max for 50 min/session, where it was maintained during the last 6 wk. Skinfold-thickness measurements, circumferences, body composition (by hydrostatic weighing), and body fat distribution (by computed tomography scan at L4-L5 and the waist-hip ratio) were determined before and after training.

RESULTS

All skinfold-thickness and circumference measures, waist-hip ratio, body mass index, total body mass, fat mass, percentage body fat, and computed tomography scan measures of total, subcutaneous, and visceral abdominal fat decreased with training, whereas total body density and fat-free mass increased. These changes were significant, but small. There were several differences in training response by sex and race, but not by age.

CONCLUSIONS

A short-term exercise intervention can induce favorable changes in body composition, but the magnitude of these changes is of limited biological significance. Increasing physical activity likely has a major effect on body-composition and fat distribution characteristics only when it is of a greater magnitude and sustained for much longer periods

Apomorphine protects against MPTP-induced neurotoxicity in mice

R-apomorphine is a potent radical scavenger and iron chelator. The neuroprotective property of R-apomorphine, a dopamine D1-D2 receptor agonist, has been studied in the MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) model of Parkinson's disease. Pretreatment with 5-10 mg/kg R-apomorphine administered subcutaneously in C57BL mice protects against MPTP (24 mg/kg administered intraperitoneally) induced loss of nigrostriatal dopamine neurons as indicated by striatal dopamine content, tyrosine hydroxylase content, and tyrosine hydroxylase activity. In vitro, R-apomorphine inhibited mice striatal MAO-A and MAO-B activities with IC50 values of 93 microM and 241 microM. It is suggested that the neuroprotective effect of R-apomorphine against MPTP neurotoxicity derives from its radical scavenging and MAO inhibitory actions and not from its agonistic activity because the mechanism of MPTP dopaminergic neurotoxicity involves the generation of oxygen radical species-induced oxidative stress.

Potent neuroprotective and antioxidant activity of apomorphine in MPTP and 6-hydroxydopamine induced neurotoxicity

Apomorphine is a potent radical scavenger and iron chelator. In vitro apomorphine acts as a potent iron chelator and radical scavenger with IC50 of 0.3 microM for iron (2.5 microM) induced lipid peroxidation in rat brain mitochondrial preparation, and it inhibits mice striatal MAO-A and MAO-B activities with IC50 values of 93 microM and 241 microM. Apomorphine (1-10 microM) protects rat pheochromocytoma (PC12) cells from 6-hydroxydopamine (150 microM) and H2O2 (0.6 mM) induced cytotoxicity and cell death. The neuroprotective property of (R)-apomorphine, a dopamine D1-D2 receptor agonist, has been studied in the MPTP (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) model of Parkinson's disease. (R)-apomorphine (5-10 mg/kg, s.c.) pretreatment in C57BL mice, protects against MPTP (24 mg/kg, i.p.) induced loss of nigro-striatal dopamine neurons, as indicated by striatal dopamine content, tyrosine hydroxylase content and tyrosine hydroxylase activity. It is suggested that the neuroprotective effect of (R)-apomorphine against MPTP neurotoxicity derives from its radical scavenging and MAO inhibitory actions and not from its agonistic activity, since the mechanism of MPTP dopaminergic neurotoxicity involves the generation of oxygen radical species induced-oxidative stress.