The role of human papillomavirus in head and neck squamous cell carcinoma: A case control study on a southern Chinese population.

HPV plays a role in the development of a portion of head and neck squamous cell carcinoma (HNSCC), but only limited information on its role in southern Chinese population is available. A multicenter case-control study was conducted. HPV type, viral integration, E6/7 mRNA expression status, and TP53 mutation were determined. A total of 228 HNSCC were recruited including 137 (60.1%) oral SCC, 34 (14.9%) oropharyngeal SCC, 31 (13.6%) laryngeal SCC, 21 (9.2%) hypopharyngeal SCC, and 5 (2.2%) lip and paranasal sinus SCC. High-risk HPV infection was found in 7.5% (17/228) of HNSCC, but only a small proportion of samples had evidence of viral integration (5.3%, 12/228) or E6/7 mRNA expression (4.4%, 10/228). HPV infection with oncogenic phenotype (integration and E6/7 mRNA expression) was significantly more common in oropharyngeal SCC than controls (9/34, 26.5% vs. 0/42, 0.0%, P < 0.001). Smoking showed a significant association with HNSCC, oropharyngeal SCC, and laryngeal SCC. TP53 mutation was associated with HNSCC (P < 0.001). Older age, TP53 mutation, and HPV16 infection with oncogenic phenotypes were independently associated factors for HNSCC with odds ratios of 1.03 (1.02-1.05), 3.38 (1.71-6.66), and 9.19 (1.13-74.68), respectively. High-risk HPV infection of head and neck mucosa is not uncommon in the Hong Kong population. This study found that 26-30% of oropharyngeal carcinoma was associated with HPV infection, mostly HPV16, and that smoking which predisposes to TP53 mutations was another important risk factor.

Ginsenoside Rg1 promotes nonamyloidgenic cleavage of APP via estrogen receptor signaling to MAPK/ERK and PI3K/Akt.

BACKGROUND: The pathogenic accumulation of amyloid ß peptide (Aß), a natural occurring peptide processed from beta-amyloid precursor protein (APP), is considered to play a key role in the development of Alzheimer's disease (AD). Ginsenoside Rg1, an active component in ginseng, has been identified as a phytoestrogen and also found to be neuroprotective. However, it is unknown whether Rg1-induced estrogenic activity intervenes in APP processing, and improves memory performance. METHODS: Using HT22 cells and SH-SY5Y cells stably expressing the Swedish mutant APP (APPsw), this study investigated whether Rg1 intervened in APP metabolism through estrogenic activity. Using the ovariectomized (OVX) rats to mimic age-related changes in postmenopausal females, this study also tested the long-term effect of Rg1 on APP metabolism. RESULTS: The in vitro study demonstrated that Rg1 increased extracellular secretion of soluble amyloid precursor protein α (sAPPα), enhanced α-secretase activity and decreased extracellular release of Aß. These effects of Rg1 could be prevented by inhibitors of protein kinase C (PKC), Extracellular-Signal Regulated Kinase/Mitogen-Activated Protein Kinase (ERK/MAPK) and Phosphoinositide-3 kinase (PI3K)/Akt pathways. Inhibition of endogenous estrogen receptor (ER) activity abrogated Rg1-triggered release of sAPPα, increase of α-secretase activity, and activation of ERK and Akt signaling. In addition, Rg1 promoted phosphorylation of ERα at Ser118 residue. The in vivo study demonstrated that 8-week Rg1 treatment of OVX rats increased sAPPα levels and decreased Aß content in the hippocampi, and improved the spatial learning and memory. GENERAL SIGNIFICANCE: Rg1 might be used to slow or prevent AD, in particular in postmenopausal females.

Quantitative assessment of gait and neurochemical correlation in a classical murine model of Parkinson's disease.

BACKGROUND: Gait deficits are important clinical symptoms of Parkinson's disease (PD). However, existing behavioral tests for the detection of motor impairments in rodents with systemic dopamine depletion only measure akinesia and dyskinesia, and data focusing on gait are scarce. We evaluated gait changes in the methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced C57BL/6 murine model of PD by using a computer-assisted CatWalk system. Correlations of gait parameters with tyrosine hydroxylase (TH) protein levels in the substantia nigra (SN) were also investigated. RESULTS: The gait readouts, including the walking duration, variation of walking speed, step cycle, duty cycle, stance, initial dual stance, terminal dual stance, three- and four-point supports, and the base of support between hind limbs was noted to increase significantly one week after MPTP injection. In contrast, values of the stride length, cadence, swing speed, and diagonal dual support decreased substantially following MPTP treatment (p < 0.05). All of these changes lasted for three weeks after the last MPTP administration. Except for the stance in the fore limbs and the swing speed in the hind limbs, the gait variability in the PD mice showed a closer correlation with the protein levels of TH in the SN than the walking distances in the conventional open field test. Coordination parameters of the regularity index and step pattern were not affected in mice treated with MPTP. CONCLUSION: Data of the study suggest that the computer-assisted CatWalk system can provide reliable and objective criteria to stratify gait changes arising from MPTP-induced bilateral lesions in C57/BL6 mice. The extent of gait changes was noted to correlate with the expression of the biomarker for dopaminergic neurons. This novel analytical method may hold promise in the study of disease progression and new drug screening in a murine PD model.

Reduced bone perfusion in osteoporosis: likely causes in an ovariectomy rat model.

PURPOSE: To investigate the cause of reduced vertebral perfusion in a rat ovariectomy model. MATERIALS AND METHODS: Experimental protocol was approved by the local Animal Experiment Ethics Committee. Twenty-two Sprague-Dawley rats were studied. Computed tomographic bone densitometry and magnetic resonance perfusion imaging were performed at baseline and 2, 4, and 8 weeks after ovariectomy (n = 11) or sham surgery (n = 11). Perfusion parameters analyzed were maximum enhancement (E(max)) and enhancement slope (E(slope)). After the animals were sacrificed, the aorta and femoral artery were analyzed for vessel reactivity, and the lumbar vertebrae were analyzed for marrow content. RESULTS: In control rats, bone mineral density (BMD), E(max), and E(slope) remained constant. In ovariectomy rats, a comparable reduction in BMD and the perfusion parameters at two weeks post-ovariectomy (BMD, 9.3%; E(max), 11.6%; E(slope), 9%) was seen 2 weeks after ovariectomy, and further reductions were seen 4 weeks (BMD, 17.5%; E(max), 15.6%; E(slope), 33%) and 8 weeks (BMD, 18.8%; E(max), 14.2%; E(slope), 33%) after ovariectomy. Endothelial dysfunction was observed in both the aorta and femoral artery of the ovariectomy group but not of the control group. Increased marrow fat area was seen in the ovariectomy group (52.9% vs 21.6%; P < .01) owing to an increase in fat cell number. Decreased erythropoetic marrow area (32.5% vs 48.6%; P < .05) was also observed in the ovariectomy group. CONCLUSION: Reduced bone perfusion occurs in synchrony with reduced BMD. The most likely causes of reduced bone perfusion are a reduction in the amount of erythropoetic marrow and endothelial dysfunction after ovariectomy. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09090608/-/DC1.

Different neuronal toxicity of single-chain ribosome-inactivating proteins on the rat retina.

OBJECTIVE: To investigate the neurotoxicity of two structurally similar single chains of ribosome-inactivating proteins (RIPs): trichosanthin (TCS) and ricin A chain (RTA). METHODS: TCS, RTA and Ricinus communis agglutinin (RCA, a multi-chain RIP for comparison) were separately injected into rat eyes. Saline was used as control. The data on cell counts, retinal thickness and histopathological scores were collected, and the TUNEL method (terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling) was used to study the mode of cell death. RESULTS: TCS caused distinct retinal changes at 1 nmol. Its toxic effects were most pronounced on the cells of the outer nuclear layer, less so on those of the inner nuclear layer, and little on the ganglion cells. Apoptosis was the predominant type of cell death induced by TCS. In contrast, RTA and RCA, both at 0.01 nmol, brought about acute retinal inflammation and necrosis. CONCLUSION: TCS can eliminate specific retinal cells by apoptosis, while RTA and RCA cause retinitis. The B chain of type II RIPs is not obligatory for their neurotoxicity. The RIPs may be useful for creating retinal models and TCS may be useful for the chemical treatment of retinoblastoma.

Development of catecholaminergic neurons in the human medulla oblongata.

Distribution and maturation of catecholaminergic (CA) neurons have been studied by tyrosine hydroxylase immunohistochemistry in the medulla oblongata of human fetuses aged 14.5-25 weeks of gestation. Already at 14.5 weeks, CA neurons were observed in two longitudinally oriented cell clusters, one located ventrolaterally in the area of the lateral reticular and ambiguous nuclei, the other one dorsomedially forming 4 groups related to the dorsal vagal nucleus, the commissural nucleus of the vagus, the nucleus of the tractus solitarius and the area postrema. CA neurons in the area postrema were often found close to blood vessels. Scattered intermediate CA neurons were seen between these two larger clusters. CA neurons still appeared immature exhibiting bipolar morphology with only one or two short stout processes, which hardly branched. At 21 weeks, CA neurons occupied essentially the same location, but had a more mature morphology. Though still bipolar in shape, they had thinner and much longer processes which frequently branched. Both in the ventrolateral and the dorsomedial cell clusters, these processes were frequently lying close to blood vessels. At 25 weeks, CA cells had matured into multipolar neurons with long thin processes forming fine fiber networks in the ventrolateral medulla as well as around and within the dorsal vagal and solitarius nuclei. Only at this stage, a distinct CA fiber tract was seen located in the region of the tractus solitarius. Our results indicate that CA neurons in the human medulla, which are presumably involved in the control of ventilation and blood pressure, though generated rather early during development, mature relatively late.

Different in vitro toxicity of ribosome-inactivating proteins (RIPs) on sensory neurons and Schwann cells.

OBJECTIVE: To study the neurotoxicity induced by Ricinus communis agglutinin (RCA), ricin A chain (RTA), and trichosanthin (TCS) in vitro. METHODS: Rat neurons and Schwann cells were cultured and real-time up-take of RIPs was traced. TUNEL, Annexin V and DAPI were employed to study the mechanism. RESULTS: The purity of both primary neuronal and Schwann cell cultures attained 80-90%. In neuritis, transport of FITC-RCA was demonstrated, but RTA and TCS were not detected. RCA elicited the strongest TUNEL and annexin V signals in both cultures. RTA evoked a stronger apoptotic signal than TCS in neurons. In contrast, compared with TCS, RTA elicited an attenuated apoptotic reaction in Schwann cells. All internalized RIPs were concentrated in the cytoplasm of the cells and their nuclei were not stained by DAPI. CONCLUSION: The toxicity of these RIPs on neurons is different from that on Schwann cells. Although they enter cells by different mechanisms they all induce apoptosis. These results may find application in in vivo neural lesioning studies and clinical therapy.

Different in vitro toxicities of structurally similar type I ribosome-inactivating proteins (RIPs).

This study was aimed at investigating and comparing the cytotoxicities of two structurally similar type I RIPs, namely trichosanthin (TCS) and free ricin A chain (RTA). A type II RIP, namely Ricinus communis agglutinin (RCA), was also included for comparison. The three RIPs were added separately to cultures of NIH 3T3 cells. The effective doses and time courses were analyzed using cell counts. Polyclonal antibodies against TCS and RTA were produced in rabbits and purified by a protein A-Sepharose CL-4B column. The mechanisms of cell death were determined by TUNEL, immunohistochemical staining, flow cytometry, and Western blotting. The effective doses for TCS, RTA and RCA were found to be 800, 50, and 50 nM, respectively. All three RIPs induced apoptosis. In all cases, activation of caspase-3 and caspase-8, but not caspase-9, was detected. Additionally, RTA caused in vivo tissue necrosis in rabbits after intradermal administration. Hence the mechanism of cell death due to RTA intoxication may vary depending on the experimental conditions, being necrosis in vivo and apoptosis in vitro. The present findings may shed light on the apoptotic pathway induced by RIPs. RTA may be useful for studying the shift in cell death.

Mechanism of the specific neuronal toxicity of a type I ribosome-inactivating protein, trichosanthin.

The aim was to study the mechanism of neuronal toxicity, the cellular pathway, and the glial cell reactions induced by trichosanthin (TCS), a type I ribosome-inactivating protein (RIP). Ricin A chain (RTA) was included for comparison. TCS, RTA, and fluorescein isothiocyanate (FITC)-labeled TCS and RTA were separately injected into rat eyes. Saline or pure FITC was used as the control. Electron microscopy, confocal microscopy, and lectin and immunohistochemical staining were used to study the neurotoxic mechanism. TCS mainly induced apoptosis by causing degeneration of the mitochondria. TCS was able to enter the Müller and pigment cells. It caused a change in cell number of the following types of glial cells: a decrease in Müller cells, an increase in astrocytes, and little change in microglia. In contrast, RTA mainly induced necrosis and entered vascular endothelial cells. Astrocyte and microglia reactions were stronger in the RTA-treated retinas than those in the TCS-treated retinas. In conclusion, TCS appears to selectively enter and destroy Müller and pigment epithelia cells, which subsequently induce the death of photoreceptors. Degeneration of mitochondria is involved in the pathways of apoptosis of the photoreceptors caused by TCS. In sharp contrast, RTA can enter vascular endothelial cells and damage the vascular endothelium, resulting in retinitis and necrosis.

Protective effects and potential mechanisms of Pien Tze Huang on cerebral chronic ischemia and hypertensive stroke.

BACKGROUND: Stroke caused by brain ischemia is the third leading cause of adult disability. Active prevention and early treatment of stroke targeting the causes and risk factors may decrease its incidence, mortality and subsequent disability. Pien Tze Huang (PZH), a Chinese medicine formula, was found to have anti-edema, anti-inflammatory and anti-thrombotic effects that can prevent brain damage. This study aims to investigate the potential mechanisms of the preventive effects of Pien Tze Huang on brain damage caused by chronic ischemia and hypertensive stroke in rats. METHODS: The effects of Pien Tze Huang on brain protein expression in spontaneously hypertensive rat (SHR) and stroke prone SHR (SHRsp) were studied with 2-D gel electrophoresis and mass spectrometric analysis with a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)/TOF tandem mass spectrometer and on brain cell death with enzyme link immunosorbent assay (ELISA) and immunostaining. RESULTS: Pien Tze Huang decreased cell death in hippocampus and cerebellum caused by chronic ischemia and hypertensive stroke. Immunostaining of caspase-3 results indicated that Pien Tze Huang prevents brain cells from apoptosis caused by ischemia. Brain protein expression results suggested that Pien Tze Huang downregulated QCR2 in the electron transfer chain of mitochondria preventing reactive oxygen species (ROS) damage and possibly subsequent cell death (caspase 3 assay) as caused by chronic ischemia or hypertensive stroke to hippocampus and cerebellum. CONCLUSION: Pien Tze Huang showed preventive effects on limiting the damage or injury caused by chronic ischemia and hypertensive stroke in rats. The effect of Pien Tze Huang was possibly related to prevention of cell death from apoptosis or ROS/oxidative damage in mitochondria.

Retrograde transport of a traditional Chinese medicine, alpha-trichosanthin, and its selective neural toxicity.

OBJECTIVE: To investigate the peripheral neuronal toxicity of a traditional Chinese medicine, alpha-trichosanthin (TCS). METHODS: TCS and rhodamine-conjugated TCS were separately injected into the rat sciatic nerve. Saline and rhodamine were used alone and separately as control solutions. The motor neurons in the spinal cord and sensory neurons in the dorsal root ganglia were separately counted. The entry of TCS molecules into neurons was observed under the fluorescence microscope. The glial reactions were studied by lectin staining and immunohistochemical method. The muscles innervated by the sciatic nerve and distal to the injection sites, and the nerves proximal to the injection sites were also collected and examined. RESULTS: TCS was taken up and transported by peripheral axons, and at a dose of 1 nmol, killed more than 90% of the motor neurons in 5 days, but only one-third of the sensory neurons of the injected nerve. The loss of neurons was permanent, while the increase of glial activities was mild and transient. CONCLUSION: TCS is retrogradely transported by axons of the injected nerve. TCS shows a selective neurotoxicity on different types of neurons. Hence TCS is useful in producing neural lesion in research, and this use may also be of applicational value in treating chronic spasticity, hyperalgesia, and pain.

Microscopic analysis of the different regions of three Alzheimer brains aged 93, 94, and 104 years old.

The brains of three Alzheimer patients aged 93, 94, and 104 years old were analyzed. Although cell death was apparent in different cortices, the prefrontal cortex and the Broca's appeared to be hit hardest. The different CA areas of the hippocampal formation all displayed equivalent degrees of cell death but the entorhinal areas showed the most severe degree of cell degeneration. Both apoptosis and necrosis were observed in the different cerebral regions of these very old patients, as expected.

Premedication with intravenous ketorolac trometamol (Toradol) in colonoscopy: a randomized controlled trial.

OBJECTIVE: We conducted a prospective double-blinded placebo-controlled randomized trial to investigate the effect of ketorolac trometamol (KT) administered intravenously as premedication in colonoscopy. METHODS: One hundred and forty patients undergoing colonoscopy were randomized to receive either 60 mg of KT (KT group (KTG), n=70) or placebo (normal saline group (NSG), n=70) intravenously as premedication 30 min prior to procedure. Patient-controlled sedation (PCS) was used as the mode of sedation. Outcome measures included patient self-assessed pain score in a 10-cm unscaled visual analog scale (VAS), endoscopist assessment of patient pain score in VAS, patient's willingness to repeat colonoscopy, administered and demanded doses of PCS, patient satisfaction score in VAS, and hemodynamic changes during and after the procedure. RESULTS: The mean patient self-assessed pain score (SD) during procedure was significantly lower in KTG than NSG: 5.08 (2.74) vs 6.62 (2.45); p=0.001. The mean endoscopist assessment of patient pain score (SD) was significantly lower in KTG than NSG as well: 3.99 (2.80) vs 5.28 (2.71); p=0.006. More patients in KTG were willing to repeat procedure as compared with NSG (80.0%vs 57.1%; p=0.004). No significant difference was found in the administered and demanded doses of PCS, mean satisfactory scores and hemodynamic changes in both groups. No serious complication related to intravenous (IV) KT was noted. CONCLUSIONS: Premedication with IV KT (Toradol) improves pain control during colonoscopy with no associated serious complications.

Pien Tze Huang protects the liver against carbon tetrachloride-induced damage.

Pien Tze Huang, a traditional Chinese medicine, has been extensively used as a therapeutic drug in the treatment of liver diseases. In this study, we have examined its ability to protect the liver from carbon tetrachloride (CCl4)-induced damage in the mouse. Histological observations revealed that CCl4 treatment induced extensive degenerative changes in the hepatocytes surrounding the central veins of the liver. However, these changes were much reduced by more than 28% in mice fed with 0.5 mg of Pien Tze Huang/g body weight/dose (3 doses over 36 hr) prior to CCl4 treatment. The effects of Pien Tze Huang were then further investigated in a hepatoma cell line. Flow analysis showed that it had no significant effects on cell proliferation. When the ability of Pien Tze Huang to influence various response elements of important signal transduction pathways was examined in the hepatoma cell line, it was found that Pien Tze Huang stimulated an increase in the response of AP1, CRE and NFkappaB responsive elements. The transcriptional factors of these responsive elements are known to play important roles in regulating cell death and survival. We thus postulate that the ability of Pien Tze Huang to protect the liver from damage is attained through its ability to modulate the activity of these important signal transduction pathways.