Quantitative magnetic resonance imaging parameters and their relationship to mammographic pattern.

BACKGROUND: Breast cancer exhibits wide international variation in incidence, which has led to the identification of several factors correlating with the risk of the disease. Magnetic resonance imaging (MRI) techniques can provide quantitative information about the biological and physical properties of tissue. PURPOSE: This work tested several magnetic resonance tissue parameters for their ability to distinguish quantitatively between breast tissues in subjects at substantially different risk for breast cancer as defined indirectly by their parenchymal pattern on mammograms. METHODS: Quantitative MRI parameters (relative water content, longitudinal relaxation time [T1], and transverse relaxation time [T2]) were measured for breast tissue using newly developed techniques in two groups of women with mammographic parenchymal appearance associated with high (Dy pattern [i.e., extensive nodular or diffuse density]; n = 12) or low (N1 pattern [i.e., breast containing mainly fat]; n = 11) risk of breast cancer. RESULTS: The two groups have significantly different average relative water content (P less than .0001) and average T1 (P less than .0001). Pixel histograms of T2 values show marked differences between the two groups which can be characterized with a fourth moment parameter. CONCLUSIONS: Quantitative MRI techniques exhibit good potential for assessing tissue characteristics in the breast that are associated with risk of breast cancer. IMPLICATIONS: Future work will address the direct correlation of MRI parameters with risk of breast cancer.     

日光诱导的人类免疫抑制作用最初由UVB、然后由UVA、最后由两者相互作用的效应引起

模拟日光的紫外线照射(ssUV)能抑制人类的机体免疫。紫外线B(UVB)波段被公认有免疫抑制作用,然而,UVA在ssUV免疫抑制中的相关重要意义仍不清楚。作者分别建立UVB、UVA及ssUV诱导的人类对镍过敏的记忆性免疫的抑制作用的量效和时效曲线。UVB在24h内引起免疫抑制,UVA引起免疫抑制     

Down syndrome and leukemia: unusual clinical aspects and unexpected methotrexate sensitivity

Twenty-four patients with Down syndrome and leukemia were studied. A strong male predominace (79%) was found. Age ranged between 18 months and 15 years (mean: 5 6/12); 54% of the patients were less than 4 years of age at the time of diagnosis. A preleukemic phase was noted in 6/24 patients. This phase, characterized essentially by thrombocytopenia, lasted from 2–8 months. Patients with preleukemia had unusual blast cell morphology and involvement of more than one cell line (dyserythropoiesis, hypolobulated megakaryocytes) and were probably M₇ leukemias. All patients demon-strated severe methotrexate toxicity at standard methotrexate doses. Toxicity, manifesting as mouth ulcerations and bone marrow depression was seen regardless of the route of administration (oral, intrathecal or intravenous). A 30%–50% reduction of the standard dose was tolerated. Methotrexate absorption and clearance were studied in two patients and were found to be normal. We postulate that the observed toxicity of methotrexate may be due to a gene dosage effect for enzymes known to be on chromosome 21 and intervening in purine metabolism. Increased purine synthesis implies greater tetrahydrofolic acid demands and therefore greater sensitivity to an antifolate agent.Abbreviations All acute lymphoblastic leukemia - AML acute myelogenous leukemia - MTX methotrexate - 6-MP 6-mercaptopurine - ITP idiopathic thrombocytopenic purpura - IV intravenous - po oral administration     

An oscillatory neuronal circuit generating a locomotory rhythm.

A quartet of interconnected interneurons whose periodic activity appears to generate the traveling body wave of the swimming leech has been identified on each side of segmental ganglia of the ventral nerve cord of Hirudo medicinalis. Theoretical analysis and electronic analog models of the identified intra- and interganglionic synaptic connections of the segmentally iterated interneurons showed that they form an oscillatory network with cycle period and intra-and intersegmental phase relations appropriate for the swimming movement.     

Recombinant tissue plasminogen activator for the treatment of spontaneous adult intraventricular hemorrhage

BACKGROUND Intraventricular hemorrhage (IVH) has a poor prognosis with mortality rates of between 80 and 100% when all four ventricles are involved. Fibrinolytic therapy has been reported to improve overall outcome.

METHODS Patients with severe primary IVH were treated by direct intraventricular injection of recombinant tissue plasminogen activator (rt-PA) into the lateral ventricles, followed by cerebrospinal fluid (CSF) drainage if the intracranial pressure rose above 20 mmHg.

RESULTS Over a 15-month period from 1995 through 1996, 10 patients were treated, (4 male and 6 female, mean age 35 years; range, 21–55 years). The mean Glasgow Coma Scale score on admission was 6 (range, 4–8) and the mean Graeb score for severity of IVH on the first CT scan was 10 (range, 8–12). Angiography was negative in five cases but identified arteriovenous malformations in three, a post-traumatic pseudoaneurysm in one, and Moya-moya disease in one. The mean total dose requirement of rt-PA was 8.25 mg (range, 6–12 mg) with a significant reduction in the mean Graeb score after 7 days to 3.9 (range, 2–7, p < 0. 0001). Outcome at 3 months was death in one case (mortality 10%), severe disability in two (20%), moderate disability in three (30%), and good result in four (40%). Four patients (40%) required subsequent CSF shunting. No complications of rehemorrhage, infection, or catheter obstruction were encountered.

CONCLUSION Intraventricular fibrinolysis with rt-PA seems to be safe and effective for the treatment of severe IVH.     

Intra-arterial revascularization therapy for basilar artery occlusion—a systematic review and analysis

Acute basilar artery occlusion has been managed aggressively with various modalities due to its potentially debilitating outcome. While intra-arterial mechanical thrombectomy with stentriever has established clear evidence for anterior circulation stroke with large vessel occlusion as an adjunct to intravenous thrombolysis or the sole modality in intravenous thrombolysis ineligible patients, similar high-level evidence was not available for intra-arterial mechanical thrombectomy of posterior circulation stroke with acute basilar artery occlusion. We hence perform a systematic review of current literature to compare intra-arterial pharmacological thrombolysis (IA-P) and intra-arterial mechanical thrombectomy (IA-MT) for acute basilar artery occlusion. Forty-one studies published between 1996 and 2015 were compared and studied by odds ratio analysis using Mantel-Haenszel risk ratio estimation, and time trend analysis using meta-regression. Patients in the IA-MT group were older, presented with more severe stroke, and more likely received treatment more than 12 h since onset of stroke. At 3 months, survival and clinical outcome were superior in the IA-MT group than the IA-P group, associated with higher recanalization rate. There were no difference between proportion of dependent survivors, and rate of symptomatic intracerebral hemorrhage across groups. Intra-arterial thrombolysis with mechanical devices led to improved survival, better short-term clinical outcome and higher recanalization rate than intra-arterial pharmacological thrombolysis.     

The management of head and neck tumors with high technology radiation therapy

Squamous cell carcinoma is responsible for 90% of the head and neck cancers affecting over 600,000 people worldwide. Radiation therapy, surgery and chemotherapy are the most important treatment modalities in head and neck squamous cell carcinoma. The aim of this review is to summarize the recent innovations in head and neck radiation therapy, which intends to appreciate the cutting-edge intensity-modulated radiation therapy strategies to mitigate long-term toxicities and evaluate promising technologies in the field as adaptive treatment, dose painting and proton therapy.     

Recurrence of hepatitis B-related hepatocellular carcinoma is associated with high viral load at the time of resection

BACKGROUND/AIMS:  To identify the risk factors for recurrence of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after resection.
METHODS:  Seventy-two patients who underwent liver resection for HBV-related HCC were recruited. Demographic, biochemical, tumor, and viral factors at the time of resection were evaluated by univariate and multivariate analyses to identify risk factors associated with recurrence after resection.
RESULTS:  The median follow-up period was 18.9 months and the median age was 53 yr, with male-to-female ratio of 59:13. Age >60 yr, tumor size >5 cm, poorly differentiated tumor, lymphovascular permeation, the presence of microsatellite lesions, α-fetoprotein (AFP) level >1,000 ng/mL and HBV viral load >2,000 IU/mL (4 log₁₀ copies/mL) at the time of tumor resection, HBV genotype C, core promoter mutations, and patients with no antiviral treatment after tumor resection were associated with increased cumulative risk of HCC recurrence. By multivariate analysis, HBV viral load >2,000 IU/mL (4 log₁₀ copies/mL) ( P = 0.001, odds ratio [OR] 22.3), AFP >1,000 ng/mL ( P = 0.02, OR 7.4), tumor size >5 cm ( P = 0.02, OR 5.1), and age >60 yr ( P = 0.01, OR 4) at the time of tumor resection remained to be the independent risk factors.
CONCLUSIONS:  Viral load of >2,000 IU/mL (4 log₁₀ copies/mL) is the most important correctable risk factor for HCC recurrence after resection. Whether antiviral therapy in these patients can decrease tumor recurrence requires further investigations.