The high regional incidence of hepatocellular carcinoma (HCC) in South Africa also may be present in children of the region, although the link to hepatitis B (HBV) appears less clear. The objective ...of this study was to assess the incidence and probable causes of HCC in South African children.
Data were obtained from seven participating pediatric oncology units and from the tumor registry to review hepatic tumors in children in South Africa.
One hundred ninety-four children (ages 0-14 years) presented with malignant primary hepatic tumors (1988-2003). One hundred twelve tumors (57%) were hepatoblastoma (HB), 68 tumors (35%) were hepatocellular carcinoma (HCC) (including 9 patients with the fibrolamellar variant, 6 of which occurred in black children), 10 tumors (5%) were sarcoma of the liver, and 4 tumors were lymphoma. The ratio of HB to HCC (1.67) was markedly lower compared with other reports, suggesting a greater prevalence of HCC. Correlation with population statistics indicated an incidence of 1.066 malignant liver tumors per year per 10(6) children age < 14 years (HB, 0.61 per 10(6) children; HCC, 0.39 per 10(6)). Two-thirds of patients with HCC were positive for HBV surface antigen (HBsAg), and HCC occurred mostly in black African patients (93%). The mean age of onset was 1.47 years for HB and 10.48 years for HCC. A preponderance of males (3.5:1.0) was noted in the HBsAg-positive group that was not reflected elsewhere. Serum alpha-fetoprotein (AFP) levels were raised both in patients with HB (100%; most AFP levels were very high) and in patients with HCC (69%), although 15% of patients with HCC had low or normal AFP levels.
It appeared from the current results that HCC is more prevalent among children in South Africa compared with the children in more developed countries, although their rates were lower that the rates noted in adults. A collaborative approach will be required to improve their diagnosis and management.
Aim
Mesenchymal hamartoma of the liver is an entity with a varied presentation and frequent initial delay in diagnosis. The macroscopic appearance too is quite heterogeneous with solid, cystic and ...mixed variants being present with varying degrees of vascularity. Management will depend on presentation and expertise available. We look at a single centre experience with the mesenchymal hamartomas.
Method
Retrospective patient record review of the past 30 years, 1976–2006.
Results
Seventeen patients aged 1 day to 15 years were identified, with a histopathological diagnosis of mesenchymal hamartoma of the liver. The anatomical location in the liver was 12 in the right liver and the 5 in the left. All patients presented with abdominal distension, eight had significant anorexia and or vomiting. Ultrasound scan was done in all patients. Findings were that of a mass and or cysts. The cysts were multiple in all cases but one and were interspersed with solid elements. Calcification was noted in only two of the patients. Operative approaches were six right hepatectomy, four wedge excision, seven tumour excisions by division of its pedicle; two of these were done laparoscopically, by cyst drainage and excision of the solid component. The tumours were all confirmed as mesenchymal hamartomas; size ranged from 412 to 2,230 g. Complications included three related to misdiagnosis (hydatid disease, and hepatoblastoma). Intraoperative problems consisted of preoperative bleeding resulting in an on-table hypovolaemic arrest and in a second case a bile duct injury. Postoperative problems consisted of an initial incomplete resection, with residual tumour on the IVC. There was rapid regrowth of tumour and death after a second exploration. Two children developed fluid collections requiring re-exploration and drainage. The surviving children have been followed up for a median time period of 4 months (range 1 month–11 years) and are well.
Conclusion
Although hamartomas of the liver are histologically benign, their clinical course and the complications of surgical treatment can be significant. They can often pose diagnostic dilemmas and may have a propensity for local recurrence and malignant degeneration.
There are no long-term medical treatments for uterine fibroids, and non-invasive biomarkers are needed to evaluate novel therapeutic interventions. The aim of this study was to determine whether ...serial dynamic contrast-enhanced MRI (DCE-MRI) and magnetization transfer MRI (MT-MRI) are able to detect changes that accompany volume reduction in patients administered GnRH analogue drugs, a treatment which is known to reduce fibroid volume and perfusion. Our secondary aim was to determine whether rapid suppression of ovarian activity by combining GnRH agonist and antagonist therapies results in faster volume reduction.
Forty women were assessed for eligibility at gynaecology clinics in the region, of whom thirty premenopausal women scheduled for hysterectomy due to symptomatic fibroids were randomized to three groups, receiving (1) GnRH agonist (Goserelin), (2) GnRH agonist+GnRH antagonist (Goserelin and Cetrorelix) or (3) no treatment. Patients were monitored by serial structural, DCE-MRI and MT-MRI, as well as by ultrasound and serum oestradiol concentration measurements from enrolment to hysterectomy (approximately 3 months).
A volumetric treatment effect assessed by structural MRI occurred by day 14 of treatment (9% median reduction versus 9% increase in untreated women; P = 0.022) and persisted throughout. Reduced fibroid perfusion and permeability assessed by DCE-MRI occurred later and was demonstrable by 2-3 months (43% median reduction versus 20% increase respectively; P = 0.0093). There was no apparent treatment effect by MT-MRI. Effective suppression of oestradiol was associated with early volume reduction at days 14 (P = 0.041) and 28 (P = 0.0061).
DCE-MRI is sensitive to the vascular changes thought to accompany successful GnRH analogue treatment of uterine fibroids and should be considered for use in future mechanism/efficacy studies of proposed fibroid drug therapies. GnRH antagonist administration does not appear to accelerate volume reduction, though our data do support the role of oestradiol suppression in GnRH analogue treatment of fibroids.
ClinicalTrials.gov NCT00746031.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Increased exposure to particulate air pollution (PM(10)) is a risk factor for death and hospitalization with cardiovascular disease. It has been suggested that the nanoparticulate component of PM(10) ...is capable of translocating into the circulation with the potential for direct effects on the vasculature.
The study's aim was to determine the extent to which inhaled technetium-99m ((99m)Tc)-labeled carbon nanoparticles (Technegas) were able to access the systemic circulation.
Ten healthy volunteers inhaled Technegas and blood samples were taken sequentially over the following 6 h. Technegas particles were 4-20 nm in diameter and aggregated to a median particle diameter of approximately 100 nm. Radioactivity was immediately detected in blood, with levels increasing over 60 min. Thin-layer chromatography of whole blood identified a species that moved with the solvent front, corresponding to unbound (99m)Tc-pertechnetate, which was excreted in urine. There was no evidence of particle-bound (99m)Tc at the origin. gamma Camera images demonstrated high levels of Technegas retention (95.6 +/- 1.7% at 6 h) in the lungs, with no accumulation of radioactivity detected over the liver or spleen.
The majority of (99m)Tc-labeled carbon nanoparticles remain within the lung up to 6 h after inhalation. In contrast to previous published studies, thin-layer chromatography did not support the hypothesis that inhaled Technegas carbon nanoparticles pass directly from the lungs into the systemic circulation.
Cerebellar granule neurons (CGNs) are one of the most populous cells in the mammalian brain. They express an outwardly rectifying potassium current, termed a "standing-outward" K+current, or IKSO, ...which does not inactivate. It is active at the resting potential of CGNs, and blocking IKSOleads to cell depolarization. IKSOis blocked by Ba2+ions and is regulated by activation of muscarinic M3receptors, but it is insensitive to the classical broad-spectrum potassium channel blocking drugs 4-aminopyridine and tetraethylammonium ions. The molecular nature of this important current has yet to be established, but in this study, we provide strong evidence to suggest that IKSOis the functional correlate of the recently identified two-pore domain potassium channel TASK-1. We show that IKSOhas no threshold for activation by voltage and that it is blocked by small extracellular acidifications. Both of these are properties that are diagnostic of TASK-1 channels. In addition, we show that TASK-1 currents expressed in Xenopus oocytes are inhibited after activation of endogenous M3muscarinic receptors. Finally, we demonstrate that mRNA for TASK-1 is found in CGNs and that TASK-1 protein is expressed in CGN membranes. This description of a functional two-pore domain potassium channel in the mammalian central nervous system indicates its physiological importance in controlling cell excitability and how agents that modify its activity, such as agonists at G protein-coupled receptors and hydrogen ions, can profoundly alter both the neuron's resting potential and its excitability.
The obscure mealybug, Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae), is a cosmopolitan pest. In New Zealand, recently introduced management tools include the host‐specific parasitoid ...Acerophagus maculipennis (Mercet) (Hymenoptera: Encyrtidae) established in 2001, and pheromone‐baited monitoring traps available since 2005. Red delta traps baited with rubber septum lures impregnated with 4.0 μg of the mealybug synthetic sex pheromone, placed in apple orchards in Hawke's Bay and Nelson, trapped both male P. viburni and female A. maculipennis. Two generations of both species per year were discernible, but numbers were low in spring and parasitoids were not trapped during winter (June to September). Male P. viburni catches reached a plateau at a pheromone dose of ca. 1.0 μg per lure but numbers of A. maculipennis per trap increased up to 100 μg per lure, the maximum dose tested. A mathematical model showed that the lures had a half‐life of about 7.4 days and were most attractive to P. viburni with a dose of 0.19 μg, and that the trap effectiveness decreased rapidly once the release rate dropped below the optimum. The model also predicted that the initial pheromone dose should be increased from 0.19 to 5.41 μg per lure as the desired period of deployment increased from 0 to 9 weeks. A dose of 4.0 μg had an initial relative effectiveness of about 55%, reached peak effectiveness after about 5 weeks, and fell to 55% relative effectiveness again after about 8.3 weeks. We conclude that an initial pheromone load of 4.0 μg is appropriate for practical monitoring of P. viburni during the New Zealand summer. Future applications of the sex pheromone for managing the pest and parasitoid are discussed.
Abstract
The obscure mealybug,
P
seudococcus viburni
(
S
ignoret) (
H
emiptera:
P
seudococcidae), is a cosmopolitan pest. In
N
ew
Z
ealand, recently introduced management tools include the ...host‐specific parasitoid
A
cerophagus maculipennis
(
M
ercet) (
H
ymenoptera:
E
ncyrtidae) established in 2001, and pheromone‐baited monitoring traps available since 2005. Red delta traps baited with rubber septum lures impregnated with 4.0 μg of the mealybug synthetic sex pheromone, placed in apple orchards in Hawke's Bay and Nelson, trapped both male
P
. viburni
and female
A
. maculipennis
. Two generations of both species per year were discernible, but numbers were low in spring and parasitoids were not trapped during winter (June to September). Male
P
. viburni
catches reached a plateau at a pheromone dose of ca. 1.0 μg per lure but numbers of
A
. maculipennis
per trap increased up to 100 μg per lure, the maximum dose tested. A mathematical model showed that the lures had a half‐life of about 7.4 days and were most attractive to
P
. viburni
with a dose of 0.19 μg, and that the trap effectiveness decreased rapidly once the release rate dropped below the optimum. The model also predicted that the initial pheromone dose should be increased from 0.19 to 5.41 μg per lure as the desired period of deployment increased from 0 to 9 weeks. A dose of 4.0 μg had an initial relative effectiveness of about 55%, reached peak effectiveness after about 5 weeks, and fell to 55% relative effectiveness again after about 8.3 weeks. We conclude that an initial pheromone load of 4.0 μg is appropriate for practical monitoring of
P
. viburni
during the New Zealand summer. Future applications of the sex pheromone for managing the pest and parasitoid are discussed.
An interlaboratory study was conducted for the validation of 3 methods for the detection of all verotoxin-producing Escherichia coli (VTEC) in foods. The methods were a multi-analyte 1-step lateral ...flow immunoassay (LFIA) for detection of E. coli O157 and verotoxin (VT); an enzyme-linked immunosorbent assay targeted against VT1, VT2, and VT2c (VT-ELISA); and a polymerase chain reaction (PCR) method for detection of VT genes (VT-PCR). Aliquots (25 g or 25 mL) of 4 food types (raw minced ground beef, unpasteurized milk, unpasteurized apple juice cider, and salami) were individually inoculated with low numbers (<9 to 375 cells/25 g) of 6 test strains of E. coli (serogroups O26, O103, O111, O145, and O157) with differing VT-producing capabilities. Five replicates for each test strain and 5 uninoculated samples were prepared for each food type. Fourteen participating laboratories analyzed samples using the LFIA, 9 analyzed the samples by ELISA, and 9 by PCR. The LFIA for O157 and VT had a specificity (correct identification of negative samples) of 92 and 94%, respectively, and a sensitivity (correct identification of positive samples) of 94 and 55%, respectively. The VT-ELISA and VT-PCR had a specificity of 98 and 99%, respectively, and a sensitivity of 89 and 72%, respectively.
Sixty patients with histologically proven lung cancer who had been accepted for mediastinoscopy or thoracotomy were prospectively entered into a study to evaluate computed tomographic (CT) scanning, ...57Co-bleomycin scanning, and barium swallow in preoperative assessment of mediastinal lymph node metastasis. Fifty-six patients had thoracotomy at which all accessible lymph nodes were sampled. Twenty-four patients were found to have mediastinal tumor on histologic analysis of the resected mediastinal lymph nodes. Neither 57Co-bleomycin scanning nor barium swallow were clinically useful, with sensitivities of 21 percent and 11 percent respectively, whereas CT scanning was helpful. However, there was no clear cutoff point of node size to optimize sensitivity and specificity for CT scanning. When nodes ≥15 mm were taken to indicate likely malignancy, the sensitivity was 58 percent and the specificity was 87 percent and when ≥10 mm was used the sensitivity was 80 percent but the specificity was only 55 percent. There was no clear relationship between the size of the largest resected lymph node in each patient and the presence of malignant lymph nodes. Only 42 percent of patients with resected nodes ≥2 cm had histologic evidence of metastases. We conclude that CT scanning should be used to indicate the presence and site of mediastinal lymph nodes, which, when visualized, should always be sampled and histologically examined prior to resection of primary tumor.
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