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Biomedical subjects

J Lane

Publications and source records attributed to J Lane.

At least 19 recordsLinked to original sources
PubMed2006

Early progressive encephalopathy in boys and MECP2 mutations.

MECP2 mutations mainly occur in females with Rett syndrome. Mutations have been described in 11 boys with progressive encephalopathy: seven of nine with affected sisters and two de novo. The authors report four de novo occurrences: three pathogenic and one potentially pathogenic. Common features include failure to thrive, respiratory insufficiency, microcephaly, and abnormal motor control. MECP2 mutations should be assessed in boys with progressive encephalopathy and one or more of respiratory insufficiency, abnormal movements or tone, and intractable seizures.

Cerebral Cortex↗
PubMed2006

Asymmetric reduction of alpha, beta-unsaturated ketone to (R) allylic alcohol by Candida chilensis.

A pilot scale whole cell process was developed for the enantioselective 1,2-reduction of prochiral alpha,beta-unsaturated ketone to (R) allylic alcohol using Candida chilensis. Initial development showed high enantiomeric excess (EE > 95%) but low product yield (10%). Process development, using a combination of statistically designed screening and optimization experiments, improved the desired alcohol yield to 90%. The fermentation growth stage, particularly medium composition and growth pH, had a significant impact on the bioconversion while process characterization identified diverse challenges including the presence of multiple enzymes, substrate/product toxicity, and biphasic cellular morphology. Manipulating the fermentation media allowed control of the whole cell morphology to a predominantly unicellular broth, away from the viscous pseudohyphae, which were detrimental to the bioconversion. The activity of a competing enzyme, which produced the undesired saturated ketone and (R) saturated alcohol, was minimized to < or =5% by controlling the reaction pH, temperature, substrate concentration, and biomass level. Despite the toxicity effects limiting the volumetric productivity, a reproducible and scaleable process was demonstrated at pilot scale with high enantioselectivity (EE > 95%) and overall yield greater than 80%. This was the preferred route compared to a partially purified process using ultra centrifugation, which led to improved volumetric productivity but reduced yield (g/day). The whole cell approach proved to be a valuable alternative to chemical reduction routes, as an intermediate step for the asymmetric synthesis of an integrin receptor antagonist for the inhibition of bone resorption and treatment of osteoporosis.

Biotransformation↗
PubMed2005

Tokelau: a unique low allergen environment at sea level.

BACKGROUND: Previous studies have shown that children in Tokelau have a lower prevalence of asthma and atopy compared to Tokelauan children resident in New Zealand. We hypothesized that the low asthma and atopy prevalence in Tokelau may be associated with low indoor allergen levels. METHODS: Dust was collected from bedding and floors of 76 homes and four public buildings in Tokelau and from the homes of 30 Tokelauan families in Wellington, New Zealand. Dust samples were analysed for Der p 1, Der f 1, Can f 1, Fel d 1, Bla g 2 and Blo t 5 by ELISA, and for endotoxin by a kinetic amoebocyte lysate assay. RESULTS: Der p 1 levels were over 1000-fold lower in Tokelau compared to New Zealand, geometric mean levels were 0.04 and 47.0 microg/g in beds and 0.04 and 44.7 microg/g on floors, respectively. Can f 1 and Fel d 1 levels were also significantly lower in Tokelau. Bed endotoxin levels were significantly higher in Tokelau, geometric mean: 26 736 EU (endotoxin units)/g, compared to 5181 EU/g in New Zealand. Floor endotoxin levels were similar between the two countries. CONCLUSION: The very low indoor allergen levels in homes in Tokelau compared to much higher levels in New Zealand homes provides a logical explanation for the lower prevalence of asthma and atopy in Tokelau, compared to New Zealand.

Allergens↗
PubMed2005

Assessing microvessels and angiogenesis in human breast cancer, using VE-cadherin.

AIMS: Vascular endothelial (VE)-cadherin, also known as cadherin-5 and CD144, is an adhesion molecule uniquely expressed in endothelial cells. We hypothesized that VE-cadherin may be a useful marker for assessing microvessels and angiogenesis in human breast cancer and sought to determine whether a correlation exists between levels of VE-cadherin, angiogenic markers factor VIII and platelet endothelial cell adhesion molecule (PECAM)-1 and patient outcome in breast cancer. METHODS AND RESULTS: Frozen sections from breast cancer primary tumours (tumour n = 114, background n = 30) were immunostained with VE-cadherin, factor VIII and PECAM-1 antibodies and microvessel number was assessed. RNA was reverse transcribed and analysed by quantitative polymerase chain reaction (Q-PCR). VE-cadherin immunostaining showed a significant difference in microvessel number in tumour compared with background. There was no significant difference in the number of microvessels stained with PECAM-1 or factor VIII; there was increased staining of other structures within the sample and higher general background staining. Q-PCR revealed elevated levels of VE-cadherin and PECAM-1 in tumour samples compared with background tissue and in patients with a poor prognosis, as determined by the Nottingham Prognostic Index. There was no difference in levels with factor VIII. Both VE-cadherin and PECAM-1 had significantly reduced expression in lobular compared with ductal carcinomas: there was no difference with factor VIII. CONCLUSION: Higher levels of angiogenic marker molecules in breast cancer may have an association with poor prognosis in patients. Moreover, VE-cadherin appears to be a preferable marker for such analysis.

Antigens, CD↗
PubMed2004

Severe factor XI deficiency caused by a Gly555 to Glu mutation (factor XI-Glu555): a cross-reactive material positive variant defective in factor IX activation.

During normal hemostasis, the coagulation protease factor (F)XIa activates FIX. Hereditary deficiency of the FXIa precursor, FXI, is usually associated with reduced FXI protein in plasma, and circulating dysfunctional FXI variants are rare. We identified a patient with < 1% normal plasma FXI activity and normal levels of FXI antigen, who is homozygous for a FXI Gly555 to Glu substitution. Gly555 is two amino acids N-terminal to the protease active site serine residue, and is highly conserved among serine proteases. Recombinant FXI-Glu555 is activated normally by FXIIa and thrombin, and FXIa-Glu555 binds activated factor IX similarly to wild type FXIa (FXIa(WT)). When compared with FXIa(WT), FXIa-Glu555 activates factor IX at a greatly reduced rate ( approximately 400-fold), and is resistant to inhibition by antithrombin. Interestingly, FXIa(WT) and FXIa-Glu555 cleave the small tripeptide substrate S-2366 with comparable k(cat)s. Modeling indicates that the side chain of Glu555 significantly alters the electrostatic charge around the active site, and would sterically interfere with the interaction between the FXIa S2' site and the P2' residues on factor IX and antithrombin. FXI-Glu555 is the first reported example of a naturally occurring FXI variant with a significant defect in FIX activation.

Antithrombin III↗
PubMed2004

Comparison of two dust collection methods for reservoir indoor allergens and endotoxin on carpets and mattresses.

Variable methods of dust collection may lead to uncertainty in the measurement of biomarkers. The purpose of this study was to examine the effect of two different dust collection devices on dust weight, Der p 1, Fel d 1, and endotoxin levels. We compared: (1) a nylon mesh sock inserted between the furniture attachment and the vacuum hose (the reference method) and (2) the ALK device. Duplicate dust samples were collected for 2 min from 2 m(2) of 37 living room floors and from each longitudinal half of 37 mattresses. Measurement of Der p 1 and Fel d 1 were by double monoclonal antibody enzyme-linked immunosorbent assay (ELISA) and endotoxin by a Limulus Amobocyte Lysate assay. Geometric mean ratios (95% confidence intervals) were calculated to show the differences between sampling devices for each measurement. Compared with the ALK device, the reference method collected significantly more dust from floors (sevenfold) and mattresses (threefold) and more total Der p 1, Fel d 1, and endotoxin in both sites. Floor, but not mattress, Der p 1 concentrations were also significantly higher (threefold) using our reference method. We recommend that, in order to minimize sampling device bias, allergen and endotoxin are expressed as a concentration, and that the bed is considered the major source of allergen exposure. Practical Implications Dust sampling equipment can influence the dust yield. In order to have confidence in comparisons of allergen and endotoxin reservoir levels between centers, standardization in the use of sampling equipment is important.

Air Pollution, Indoor↗
PubMed2003

Tic reduction with pergolide in a randomized controlled trial in children.

OBJECTIVE: To determine whether pergolide, a mixed D1/D2/D3 dopamine agonist, is efficacious and safe in the treatment of children with chronic tic disorders and Tourette syndrome. BACKGROUND: Neuroleptics, which block dopamine transmission, are currently used to treat children with severe tics, but major side effects and limited efficacy reduce clinical utility. Prior open-label and crossover studies of pergolide suggest potential benefit. METHODS: The authors enrolled 57 children and adolescents, ages 7 to 17 years, randomizing them in a 2:1 ratio to either pergolide (0.15 to 0.45 mg per day) or placebo. Tic symptoms had to be >30 on the Yale Global Tic Severity Scale (YGTSS). The primary outcome measure was change in tic severity assessed by YGTSS. RESULTS: Compared to placebo treatment, pergolide treatment was associated with lower tic severity scores (treatment effect 8.8, pergolide vs placebo; 95% CI 0.1 to 17.6; p = 0.05) and attention-deficit hyperactivity disorder symptoms scores (treatment effect 3.8; 95% CI 0.7 to 6.8; p = 0.02). No patient had a serious adverse event and pergolide was well tolerated. CONCLUSIONS: In this randomized, placebo-controlled trial, pergolide appeared to be an efficacious and safe medication for tic reduction in children, and may also improve attention-deficit hyperactivity disorder symptoms.

Adolescent↗
PubMed2003

Ultrasound in the detection and treatment of a painful stump neuroma.

Ultrasound is an established modality for the evaluation of neuromas, particularly Morton's neuromas. It has also had success in the assessment of amputation stump neuromas. While ultrasound localization for steroid injection has proven useful in the conservative treatment of Morton's neuromas, it has not yet been established as a localization technique for steroid injection to successfully treat amputation stump neuromas.

Amputation, Surgical↗
PubMed2002

From PCR to RCA: a surgical trainee's guide to the techniques of genetic amplification.

With the advent of evidence-based medicine and the Calman-Hine Report, more and more surgical trainees are undertaking a period of research, either before entering or during their Specialist Registrar training. Many will encounter concepts in science uncommon in daily clinical settings. This paper will elucidate the techniques of genetic amplification available today with their potential for usage in clinical research.

Evidence-Based Medicine↗
PubMed2001

Clinical prognosis of patients with early-stage human immunodeficiency virus (HIV) disease: contribution of HIV-1 RNA and T lymphocyte subset quantitation.

Systems for the staging of individuals with human immunodeficiency virus type 1 (HIV-1) infection were developed 15 years ago. Subsequently, assays for quantitating HIV-1 RNA and immunophenotyping of lymphocyte subsets have been developed and validated. The utility of these assays for improved staging in early disease was evaluated in 256 HIV-infected adults (52% minority) with CD4 counts > or = 400 cells/microL followed in U.S. military medical centers before the highly active anti-retroviral therapy era. HIV viral load (RNA) was quantitated; the frequencies of select CD4+ immunophenotypes were determined in 112 subjects. The results were analyzed in relation to three outcome measures: death, first acquired immunodeficiency syndrome-defining opportunistic infection, and CD4 count < or = 200 cells/microL. Serum RNA level and CD4 count were each found to be predictive of all three outcomes. In addition, increases in the T-cell subsets CD28-CD4+ and CD29+CD26-CD4+ were found to be independently predictive of more rapid progression. The classification of early-stage HIV patients is improved by the quantitation of both viral RNA and T-lymphocyte subsets.

Adult↗
PubMed2001

A hammerhead ribozyme suppresses expression of hepatocyte growth factor/scatter factor receptor c-MET and reduces migration and invasiveness of breast cancer cells.

PURPOSE: Hepatocyte growth factor/scatter factor (HGF/SF), via its receptor c-MET, has been implicated to play a pivotal role in breast cancer development and progression. This study examined a transgene-consisting of a combination of U1snRNA, hammerhead ribozyme, and antisense, designed to inhibit c-met expression-and its impact on the migration and in vitro invasion of breast cancer cells. EXPERIMENTAL DESIGN: A hammerhead ribozyme targeting human c-MET was cloned into a modified pZeoU1EcoSpe vector and transfected into breast cancer cells MDA MB 231 and MCF-7 by electroporation. Expression of MET mRNA and protein was determined. Migration and in vitro invasiveness of transfected cells were also analyzed. RESULTS: Breast cancer cells were transfected with the ribozyme-containing plasmids. Stable transfectants manifested an almost complete loss of MET mRNA and protein, as shown by reverse transcription-PCR, Northern blotting, and Western blotting, respectively, whereas the wild-type plasmid had no effects. Met-ribozyme transfected cells exhibited reduced migration and in vitro invasiveness through extracellular matrix (Matrigel), compared with the wild-type cells and cells transfected with empty plasmid. CONCLUSIONS: These data show that targeting c-MET by way of a hammerhead ribozyme encoding antisense to c-MET is an effective approach in reducing the invasiveness of breast cancer cells.

Base Sequence↗
PubMed2000

A naturalistic investigation of the effects of day-long consumption of tea, coffee and water on alertness, sleep onset and sleep quality.

RATIONALE: The effects of caffeine, especially caffeinated coffee, on human performance have been extensively studied. However, few studies have been naturalistic representations of how tea/coffee is normally consumed in terms of dose and time of consumption. OBJECTIVES: This study investigated the effects of day-long consumption of tea, coffee and water on cognitive and psychomotor performance, and sleep quality at night. METHODS: Thirty healthy volunteers received equal volume drinks equivalent to either 1 or 2 cups of tea (containing 37.5 mg or 75 mg caffeine), or coffee (75 mg or 150 mg caffeine), or water, in a randomised five-way crossover design. Drinks were administered on four occasions during the day (0900, 1300, 1700 and 2300 hours). A psychometric battery consisting of critical flicker fusion (CFF), choice reaction time (CRT) and subjective sedation (LARS) tests, was administered pre-dose and at frequent time points post-dose. The Leeds Sleep Evaluation Questionnaire (LSEQ) was completed each morning and a wrist actigraph was worn for the duration of the study. RESULTS: Caffeinated beverages maintained CFF threshold over the whole day (P<0.05), independent of caffeine dose or beverage type. During the acute phase of beverage ingestion, caffeine significantly sustained performance compared to water after the first beverage for CFF and subjective sedation (P<0.05), and after the second beverage for the Recognition component of the CRT task (P<0.05). Additionally, there were significant differences between tea and coffee at 75 mg caffeine after the first drink. Compared to coffee, tea produced a significant increase in CFF threshold between 30 and 90 min post-consumption (P<0.01). However, following the second beverage caffeinated coffee at 75 mg significantly improved reaction time (P<0.05), compared to tea at the same dose, for the Recognition component of the CRT task. Caffeinated beverages had a dose dependent negative effect on sleep onset (P<0.001), sleep time (P<0.001) and sleep quality (P<0.001). CONCLUSIONS: These results indicate that ingestion of caffeinated beverages may maintain aspects of cognitive and psychomotor performance throughout the day and evening when caffeinated beverages are administered repeatedly. This study also demonstrates that day-long tea consumption produces similar alerting effects to coffee, despite lower caffeine levels, but is less likely to disrupt sleep. Other differences between tea and coffee were more subtle, and require further investigation.

Adult↗
PubMed2000

A chloride-activated Na(+)/HCO(3)(-)-coupled transport activity in corneal endothelial membranes.

Investigations of corneal endothelium were made to resolve the apparent contradiction of the presence of sodium/bicarbonate cotransporter (NBC) in fresh and cultured cells and NBC's reported absence in isolated plasma membrane vesicles. Gradient-driven ion fluxes into the vesicles were measured. Short-term incubations (0-30 s) showed the presence of a bicarbonate-dependent inward sodium flux (BDSF), which was active when the insides of the vesicles were preloaded with chloride ions. The BDSF was absent if chloride was present only externally to the vesicles. Chloride at concentrations between 30 and 40 mM inside the vesicle had its maximum effect on BDSF. Other anions (acetate, thiocyanate, or gluconate) inside the vesicles did not mimic the chloride effect. Associated with the net inward sodium flux was a net inward bicarbonate flux. Hill plots of sodium influx with respect to external bicarbonate concentrations indicated that the stoichiometry of the net transfer was 1.7 +/- 0.2 (mean +/- standard error, n = 5) bicarbonate ions for each sodium ion transported. There was no net chloride flux found across the membrane vesicles. The finding of a novel chloride-activated NBC activity fully resolves the apparent contradiction between whole-cell and membrane vesicle preparations.

Animals↗
PubMed2000

The acute physiological and mood effects of tea and coffee: the role of caffeine level.

The objective of this study was to determine the effect of caffeine level in tea and coffee on acute physiological responses and mood. Randomised full crossover design in subjects after overnight caffeine abstention was studied. In study 1 (n = 17) the caffeine level was manipulated naturalistically by preparing tea and coffee at different strengths (1 or 2 cups equivalent). Caffeine levels were 37.5 and 75 mg in tea, 75 and 150 mg in coffee, with water and no-drink controls. In study 2 (n = 15) caffeine level alone was manipulated (water, decaffeinated tea, plus 0, 25, 50, 100, and 200 mg caffeine). Beverage volume and temperature (55 degrees C) were constant. SBP, DBP, heart rate, skin temperature, skin conductance, and mood were monitored over each 3-h study session. In study 1, tea and coffee produced mild autonomic stimulation and an elevation in mood. There were no effects of tea vs. coffee or caffeine dose, despite a fourfold variation in the latter. Increasing beverage strength was associated with greater increases in DBP and energetic arousal. In study 2, caffeinated beverages increased SBP, DBP, and skin conductance and lowered heart rate and skin temperature compared to water. Significant dose-response relationships to caffeine were seen only for SBP, heart rate, and skin temperature. There were significant effects of caffeine on energetic arousal but no consistent dose-response effects. Caffeinated beverages acutely stimulate the autonomic nervous system and increase alertness. Although caffeine can exert dose-dependent effects on a number of acute autonomic responses, caffeine level is not an important factor. Factors besides caffeine may contribute to these acute effects.

Adult↗
PubMed2000

Role of Na+-glucose cotransport in jejunal meal-induced absorption.

In awake dogs, meal ingestion stimulates the absorption of water and electrolytes from neurovascularly intact jejunal Thiry-Vella loops, even though these loops are isolated from the remainder of the gut. This study was designed to investigate the role of Na+-glucose cotransport in mediating this event. Meal ingestion enhanced absorption when the jejunal lumen was perfused with an isotonic solution containing D-glucose, D-galactose, or 3-O-methylglucose. This response was absent when the perfusate contained mannitol or when phlorizin was added to the D-glucose solution. Mucosa from the jejunal loops was serially biopsied and assayed for brush-border Na+-glucose cotransporter (SGLT1) mRNA and protein expression. Although no changes in SGLT1 mRNA levels were observed, protein levels significantly increased within 30 min following meal ingestion. The time course of SGLT1 protein expression corresponded with that of increased Na+ and water absorption. These results suggest that meal-stimulated jejunal absorption may be mediated through an induction of mucosal SGLT1.

Adaptation, Physiological↗
PubMed2000

Maintenance of bone density: outcomes over five years of attendance at an osteoporosis center.

BACKGROUND: This is a longitudinal analysis of the data from women who visited the Osteoporosis Prevention Center for at least five years. The study is part of an ongoing evaluation of the results of the Center visits. METHODS: A random sample of 100 women who had attended the clinic for more than five years and were not referred for a definite medical diagnosis was pulled from the records. Descriptive statistics were compiled on this sample. Seventy-five women were postmenopausal and over 49 years of age. This subgroup was studied for change in bone mineral density (BMD) over the five years. RESULTS: The BMD change was 0.03 gm/cm2 in the spine, -0.01 gm/cm2 in the femoral-neck. and -0.008 gm/cm2 at the radius over the five years. CONCLUSION: Attendance at the Osteoporosis Prevention Center was associated with maintenance of bone density in the spine over a five-year period.

Aged↗