In vivo imaging of neuroblastomas using GD2-targeting graphene quantum dots

BackgroundPatients with neuroblastoma, a common childhood malignancy, often have poor prognosis. It is mandatory to develop an accurate and efficient diagnostic tool for neuroblastomas, so that the treatment can be started early. Graphene quantum dot (GQD), a nanomaterial, can be used to carry proteins, genetic materials, or drugs. GD2, a disialoganglioside, is a surface antigen expressed on neuroblastoma. This study investigated the in vivo targeting and imaging of neuroblastomas using GD2-targeting GQDs.MethodsGQDs were synthesized and conjugated with anti-GD2 antibody (anti-GD2/GQDs). In vitro cytotoxicity of GQDs and anti-GD2/GQDs was studied in human neuroblastoma cells by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide)-based colorimetric assay. The tumor tracking and imaging of anti-GD2/GQDs in mice were investigated by in vivo imaging system (IVIS).ResultsTreatment with GQDs or anti-GD2/GQDs induced no or mild cytotoxicity in fibroblasts and neuroblastoma cells. After co-incubation, GQDs and anti-GD2/GQDs were located in the cytoplasm and nucleus of neuroblastoma cells, with GQDs showing a blue fluorescence and anti-GD2/GQDs an orange/red emission. The IVIS images demonstrated accumulation of the fluorescence of anti-GD2/GQDs in the subcutaneous tumors in mice 24 h after intravenous injection of anti-GD2/GQDs.ConclusionsAnti-GD2/GQDs may potentially be used for the targeting and imaging of neuroblastomas in vivo.     

Measuring patient perceptions of surgeon communication performance in the treatment of thyroid nodules and thyroid cancer using the communication assessment tool

BackgroundThyroid surgeons are offering their patients less aggressive diagnostic and therapeutic management strategies for thyroid nodules and low-risk thyroid cancer in an effort to decrease overdiagnosis and overtreatment of indolent disease. Explaining the rationale for less aggressive management plans requires physicians to be effective communicators. We aimed to assess the communication skills of thyroid surgeons with the Makoul Communication Assessment Tool and to identify risk factors for poor communication.MethodsNew adult patients with thyroid nodules or thyroid cancer presenting to a single tertiary-referral endocrine surgery clinic were enrolled from July 2018 through December 2019. Patients were administered the Communication Assessment Tool immediately after their clinical encounter. Outlier communication scores were identified, and clinical characteristics were compared between outlier and nonoutlier groups.ResultsA total of 107 patients completed the Communication Assessment Tool. Mean (standard deviation) total and top box scores were 67 (6) and 86% (29%), respectively. Twenty-five patients (23%) were in the low-outlier group, defined by a total score below 67.5/70 or top box score below 82.25%. Other race and non-Hispanic patients (versus white race) were more likely low outliers (odds ratio 3.58, P = .048). The lowest scoring Communication Assessment Tool item overall was “the doctor encouraged me to ask questions” (78.5% top box).ConclusionWe found communication to be perceived as excellent in the majority of patients; however, an opportunity for improvement was identified in 29% of participants. Significant differences in race and ethnicity between low outlier and nonoutlier communication score patients were observed, which warrants additional investigation. These findings support the utility of the Communication Assessment Tool in studying the effectiveness of communication improvement initiatives.     

Allosteric effects of mutations in the extracellular S5-P loop on the gating and ion permeation properties of the hERG potassium channel

The hERG channel has an unusually long (39 amino acids) extracellular loop between the transmembrane S5 segment and the pore region that may play a role in channel function. We explored this possibility by mutating two histidine residues in this region (H578 and H587, referred to as H1 and H2) to various residues and examined the resulting changes in channel function. Both positions could tolerate drastic changes in side-chain properties (proline, cysteine, glutamate and lysine), indicating that they are solvent exposed. None of the H1 mutations affected hERG channel function. On the other hand, although replacing H2 with glutamate had little or no effect on hERG properties, putting a proline or lysine at this position disrupted the C-type inactivation process and the pore's K selectivity. There was also a hyperpolarizing shift in the voltage dependence of activation. The phenotype of the H2C mutant was similar to that of H2P or H2K. However, dithiothreitol (DTT, a thiol-reducing agent) treatment converted the H2C phenotype to that of the wild-type channel. These observations suggest that the peptide backbone conformation around position 587 in the extracellular S5-P loop of hERG channel can affect the channel's gating and ion selectivity functions.     

Inflammatory cloacogenic polyp of anus: report of three cases

The term of "cloacogenic anal carcinoma", "cloacogenic zone" and "cloacal membrane" have been widely used, but the term of "inflammatory cloacogenic polyp" (ICP) was first applied and published by Lobert PF and Henry DA in 1981. Here we present three cases of ICP to stress its inflammatory property, predilection to invade cloacogenic zone of anus and polypoid shape, and to differentiate it from its related lesions as concise as possible.     

Nonhereditary p53 mutations in T-cell acute lymphoblastic leukemia are associated with the relapse phase

We have previously reported that greater than 60% of human leukemic T- cell lines possess mutations in the p53 tumor suppressor gene. To determine whether T-cell acute lymphoblastic leukemia (T-ALL) patient samples possess p53 mutations, we screened peripheral blood-and bone marrow-derived leukemia samples, taken at diagnosis and at relapse, for p53 mutations. Exons 4 through 9 and selected intron regions of the p53 gene were analyzed using polymerase chain reaction-single-strand conformation polymorphism and direct sequencing. p53 mutations were found in 0 of 15 T-ALL diagnosis samples, as compared with 10 of 36 (28%) T-ALL relapse samples. To determine whether p53 mutations play a role in the recurrence (relapse) of T-ALL, two special groups of T-ALL patients were studied: (1) a group of 8 relapse patients whose disease was refractory to chemotherapeutic treatment, and (2) a group of 6 "paired" T-ALL cell samples from patients for whom we possess both diagnosis and relapse samples. Three of 8 relapsed patients (37.5%) whose disease was refractory to the reinduction of remission by chemotherapy possessed missense mutations of the p53 gene. All 3 cases had mutations in exon 5. Among the paired samples, 3 of 6 patients harbored p53 mutations at disease recurrence, but possessed only wild- type p53 alleles at diagnosis. One case had mutation on exon 4, 1 case in exon 5, and 1 case in exon 8 with loss of heterozygosity. These data clearly indicate that recurrence of T-ALL is associated with missense mutations in p53. Our results indicate that (1) mutations of p53 do occur in T-ALL in vivo, and such mutations are associated with the relapse phase of the disease; and (2) p53 mutation is involved in the progression of T-ALL. This conclusion is supported by our observation that the introduction of T-ALL-derived mutant p53 expression constructs into T-ALL cell lines further increases their growth rate in culture, enhances cell cloning in methylcellulose, and increases tumor formation in nude mice.     

Vertical root fracture in endodontically versus nonendodontically treated teeth: a survey of 315 cases in Chinese patients

OBJECTIVE: The purpose of this study was to compare endodontically versus nonendodontically treated teeth with respect to clinical features, including patient age and gender and tooth types of vertical root fractures. STUDY DESIGN: A total of 315 consecutive cases of vertical root fracture occurring in 274 Chinese patients during a 1 3-year period were reviewed. Age and gender, as well as tooth type and root distribution of vertical root fractures, were presented and compared in endodontically versus nonendodontically treated teeth. RESULTS: Most patients (87%) had 1 fractured tooth; the others had 2 or 3 fractured teeth. Of all vertical root fractures, 40% occurred in nonendodontically treated teeth. In comparison with those in endodontically treated teeth, vertical root fractures in nonendodontically treated teeth tended to occur in patients with a higher mean age (55 years vs. 51 years) and were more frequent in male patients (78% vs. 58%). Vertical root fractures occurred in nonendodontically treated teeth more often in molars (84% vs. 53%), less often in premolars (16% vs. 33%), and seldom in anteriors (1 tooth vs. 27 teeth). CONCLUSIONS: Vertical root fractures in nonendodontically treated teeth are not uncommon and comprise a large proportion of such fractures in Chinese patients. Differences between endodontically and nonendodontically treated teeth in patient age and gender, as well as in tooth types of vertical root fractures, were demonstrated.     

Increased intracerebral excitatory amino acids and nitric oxide after hypothermic circulatory arrest

BACKGROUND: Prolonged hypothermic circulatory arrest (HCA) results in neurologic injury, but the mechanism of this injury is unknown. This study was undertaken to measure quantitatively intracerebral excitatory amino acids and citrulline, an equal coproduct of nitric oxide, during HCA. We hypothesized that HCA resulted in higher levels of glutamate, aspartate, glycine, causing increased intracellular calcium, and therefore, nitric oxide and citrulline. METHODS: Ten dogs underwent intracerebral microdialysis and 2 hours of HCA at 18 degrees C. Effluent was analyzed by high performance liquid chromatography with electrochemical detection. Five dogs each were sacrificed at 8 and 20 hours after HCA. Neuronal apoptosis was scored from 0 (no injury) to 100 (severe injury). RESULTS: Time course of HCA was divided into six periods. Peak levels of amino acids in each period were compared with those at baseline. Glutamate, coagonist glycine, and citrulline, an equal coproduct of nitric oxide, increased significantly over baseline during HCA, cardiopulmonary bypass, and 2 to 8 hours after HCA. Aspartate increased significantly during HCA and 8 to 20 hours after HCA. Apoptosis score was 65.56 +/- 5.67 at 8 hours and 30.63 +/- 14.96 at 20 hours after HCA. CONCLUSIONS: Our results provide direct evidence that HCA causes increased intracerebral glutamate and aspartate, along with coagonist glycine. We conclude that HCA causes glutamate excitotoxicity with subsequent nitric oxide production resulting in neurologic injury, which begins during arrest and continues until 20 hours after hypothermic circulation arrest. To provide effective cerebral protection, pharmacologic strategies to reduce glutamate excitotoxicity require intervention beyond the initial ischemic insult.     

D-amphetamine-induced depletion of energy and dopamine in the rat striatum is attenuated by nicotinamide pretreatment

The present study examined the effects of nicotinamide on the D-amphetamine (AMPH)-induced dopamine (DA) depletion and energy metabolism change in the rat striatum. In chronic studies, co-administration of AMPH with desipramine, a drug that retards the metabolism of AMPH, (10 mg/kg, intraperitoneal [i.p.], respectively) caused a significant decrease of striatal DA content measured 7 days later. Pretreatment with nicotinamide (500 mg/kg, i.p.), the precursor molecule for the electron carrier molecule nicotinamide adenine dinucleotide (NAD), attenuated this effect of AMPH, whereas itself exerted no long-term effect on striatal DA content. In acute studies, a decrease in striatal adenosine triphospate/adenosine diphosphate (ATP/ADP) ratio was found 3 h after co-injection of AMPH and desipramine. However, nicotinamide pretreatment blocked the reduced striatal ATP/ADP ratio and resulted in a striking increase in striatal NAD content in AMPH-treated rats. Furthermore, nicotinamide was noted to increase striatal ATP/ADP ratio and NAD content in saline-treated rats. These findings suggest that nicotinamide protects against AMPH-induced DAergic neurotoxicity in the striatum of rats via energy supplement.