ML216-Induced BLM Helicase Inhibition Sensitizes PCa Cells to the DNA-Crosslinking Agent Cisplatin.

Using standard DNA-damaging medicines with DNA repair inhibitors is a promising anticancer tool to achieve better therapeutic responses and reduce therapy-related side effects. Cell viability assay, neutral comet assay, western blotting (WB), and cell cycle and apoptosis analysis were used to determine the synergistic effect and mechanism of ML216, a Bloom syndrome protein (BLM) helicase inhibitor, and cisplatin (CDDP), a DNA-crosslinking agent, in PCa cells. Based on the online database research, our findings revealed that BLM was substantially expressed in PCa, which is associated with a bad prognosis for PCa patients. The combination of ML216 and CDDP improved the antiproliferative properties of three PCa cell lines. As indicated by the increased production of γH2AX and caspase-3 cleavage, ML216 significantly reduced the DNA damage-induced high expression of BLM, making PC3 more susceptible to apoptosis and DNA damage caused by CDDP. Furthermore, the combination of ML216 and CDDP increased p-Chk1 and p-Chk2 expression. The DNA damage may have triggered the ATR-Chk1 and ATM-Chk2 pathways simultaneously. Our results demonstrated that ML216 and CDDP combination therapy exhibited synergistic effects, and combination chemotherapy could be a novel anticancer tactic.

Specific immunoassay reveals increased serum trypsinogen 3 in acute pancreatitis.

BACKGROUND: Trypsinogen 3 is a minor trypsinogen isoform in the pancreas. In contrast with trypsin 1 and 2, trypsin 3 degrades pancreatic secretory trypsin inhibitor, which may lead to an excess of active trypsin and acute pancreatitis (AP). We developed an immunoassay for trypsinogen 3 and studied whether an assay of serum trypsinogen 3 is of clinical utility in the diagnosis of AP. METHODS: Monoclonal antibodies were generated using recombinant human trypsinogen 3 as the antigen and used to establish a sandwich-type immunoassay. We analyzed serum trypsinogen 3 concentrations in 82 patients with AP and 63 patients with upper abdominal pain (controls). The reference interval was determined using serum samples from 172 apparently healthy individuals. RESULTS: The measuring range of the trypsinogen 3 assay was 1.0-250 µg/L. Intra- and interassay CVs were <11%, and cross-reactivity with other trypsinogen isoenzymes was <0.1%. The median trypsinogen 3 concentration in serum from healthy individuals was <1.0 µg/L, and the upper reference limit was 4.4 µg/L. We observed increased trypsinogen 3 concentrations in patients with mild (median 9.5 µg/L) and severe (15.0 µg/L) AP; in both groups, the concentrations were significantly higher than in controls (median <1.0 µg/L) (P < 0.0001). In ROC analysis, the area under the curve of trypsinogen 3 for separation between AP and controls was 0.90 (P < 0.0001). CONCLUSIONS: We established for the first time a specific immunoassay for trypsinogen 3 using monoclonal antibodies. Patients with AP were found to have increased serum concentrations of trypsinogen 3. The availability of this assay will be useful for studies of the clinical utility of trypsinogen 3.

Studies of the neural mechanisms of deep brain stimulation in rodent models of Parkinson's disease.

Several rodent models of deep brain stimulation (DBS) have been developed in recent years. Electrophysiological and neurochemical studies have been performed to examine the mechanisms underlying the effects of DBS. In vitro studies have provided deep insights into the role of ion channels in response to brain stimulation. In vivo studies reveal neural responses in the context of intact neural circuits. Most importantly, recording of neural responses to behaviorally effective DBS in freely moving animals provides a direct means for examining how DBS modulates the basal ganglia thalamocortical circuits and thereby improves motor function. DBS can modulate firing rate, normalize irregular burst firing patterns and reduce low frequency oscillations associated with the Parkinsonian state. Our current efforts are focused on elucidating the mechanisms by which DBS effects on neural circuitry improve motor performance. New behavioral models and improved recording techniques will aide researchers conducting future DBS studies in a variety of behavioral modalities and enable new treatment strategies to be explored, such as closed-loop stimulations based on real time computation of ensemble neural activity.

Studies of the neural mechanisms of deep brain stimulation in rodent models of Parkinson's disease.

Several rodent models of deep brain stimulation (DBS) have been developed in recent years. Electrophysiological and neurochemical studies have been performed to examine the mechanisms underlying the effects of DBS. In vitro studies have provided deep insights into the role of ion channels in response to brain stimulation. In vivo studies reveal neural responses in the context of intact neural circuits. Most importantly, recording of neural responses to behaviorally effective DBS in freely moving animals provides a direct means for examining how DBS modulates the basal ganglia thalamocortical circuits and thereby improves motor function. DBS can modulate firing rate, normalize irregular burst firing patterns and reduce low-frequency oscillations associated with the Parkinsonian state. Our current efforts are focused on elucidating the mechanisms by which DBS effects on neural circuitry improve motor performance. New behavioral models and improved recording techniques will aide researchers conducting future DBS studies in a variety of behavioral modalities and enable new treatment strategies to be explored, such as closed-loop stimulations based on real-time computation of ensemble neural activity.

[Pituitary abscess in a child].

As a clinically rare condition, pituitary abscess lacks a definite history of infection or characteristic symptoms such as fever or meningismus for a definite diagnosis. From the experience with a case of pituitary abscess in a child, we urged that attention should be given to differentiation of this condition from cystoid changes of the pituitary tumor, craniopharyngioma, Rothka cyst, sphenoidal sinus cyst and sphenoidal sinus abscess.

[Protective effect of exogenous superoxide dismutase against rat midbrain dopaminergic neuron apoptosis induced by 6-hydroxydopamine].

OBJECTIVE: To observe the changes of total antioxidant ability of rat midbrain and T-superoxide dismutase (T-SOD) activity, and define the relation between oxidative stress and dopaminergic neuron apoptosis induced by 6-hydroxydopamine (6-OHDA), observing also the protection of the exogenous SOD against the neuron apoptosis. METHODS: A total of 144 SD rats was randomized into normal control, model control, model, treatment control and treatment groups according to different treatments the rats received. The treatment group was subdivided into A, B, C, D and E groups with different treating times after model establishment. The midbrain total antioxidant ability, T-SOD activity, and active oxygen were measured by using corresponding detection kits, and the behavioral changes and the changes of tyrosine hydroxylase(TH) immunoreactivity and apoptotic cells in the substantia nigra compact part (SNcp) were assessed and measured in each group. RESULTS: After injection of 6-OHDA in SNcp of rats, the total antioxidant ability did not undergo obvious changes. Active oxygen in the midbrain increased remarkably to 130+/-17 U/mg prot and T-SOD activity was reduced. Injection of exogenous SOD caused the rotational speed of the rats to decrease from 166.7+/-31.0 to 87.6+/-25.0 circle/30 min following intraperitoneal injection of apomorphine (0.5 mg/kg b.w.), with obviously decreased active oxygen (P<0.05) and enhanced T-SOD activity. TH immunoreactivity and cell apoptosis in the SNcp presented corresponding changes. In the treatment groups, different time schedules for exogenous SOD injection into the SNcp produced different effects accordingly. CONCLUSION: Oxidative stress plays an important role in doparminergic neuron apoptosis induced by 6-OHDA injection. Exogenous SOD in the SNcp effectively reduces active oxygen, promotes the antineurotoxic ability of doparminergic neurons, reduces doparminergic neuron apoptosis and ameliorated the rat rotating behavior. Exogenous SOD has short-term antioxidant effect, which weakens progressively over extended time.

Long-term high-frequency electro-acupuncture stimulation prevents neuronal degeneration and up-regulates BDNF mRNA in the substantia nigra and ventral tegmental area following medial forebrain bundle axotomy.

Electroacupuncture (EA) has been used in China for many years to treat Parkinson's disease (PD) with reportedly effective results. However, the physiological and biological mechanism behind its effectiveness is still unknown. In the present study, different frequencies of chronic EA stimulation (0, 2, 100 Hz) were tested in a partially lesioned rat model of PD which was induced by transection of the medial forebrain bundle (MFB). After 24 sessions of EA stimulation (28 days after MFB transection), dopaminergic neurons in the ventral midbrain were examined by immunohistochemical staining, and brain-derived neurotrophic factor (BDNF) mRNA levels in ventral midbrain were measured by in situ hybridization. The results show a marked decrease of dopaminergic neurons on the lesioned side of the substantia nigra (SN) comparing with the unlesioned side. Zero Hz and 2 Hz EA stimulation had no effect on the disappearance of dopaminergic neurons. However, after 100 Hz EA, about 60% of the tyrosine hydroxylase (TH)-positive neurons remained on the lesioned side of the SN. In addition, levels of BDNF mRNA in the SN and ventral tegmental area (VTA) of the lesioned side were significantly increased in the 100 Hz EA group, but unchanged in the 0 and 2 Hz groups. Our results suggest that long-term high-frequency EA is effective in halting the degeneration of dopaminergic neurons in the SN and up-regulating the levels of BDNF mRNA in the subfields of the ventral midbrain. Activation of endogenous neurotrophins by EA may be involved in the regeneration of the injured dopaminergic neurons, which may underlie the effectiveness of EA in the treatment of PD.