Selective accumulation of lymphocyte precursor cells mediated by stromal cells of hemopoietic origin

Thymocytes were propagated in long-term cultures supported by stromal cells of both bone marrow and thymus origin. Interleukin 2 (IL-2) supplementation augmented the cell yield and allowed detailed phenotype analysis. Within 2-3 months of culture a cell population was selected in which the expression of Thy-1 antigen persisted, CD4 and CD8 antigens gradually declined, and Pgp-1 antigen, found on less than 5% of fresh thymocytes, was strongly increased. This cultured cell population (Thy-1.2 origin) contained no detectable spleen colony-forming units (CFU-S) but efficiently repopulated the thymus of Thy-1.1-irradiated congenic mice, indicating the precursor T-cell nature of the population. Upon removal from the stroma, the T cells exhibited poor cytotoxicity towards syngeneic tumor cells. Further propagation with IL-2 in the absence of stroma resulted in the acquisition of cytotoxic ability. Replacement of the horse serum used in the above experiments with fetal calf serum resulted in accumulation of cells expressing B220 antigen. This experimental model provides the means to maintain lymphocyte precursor cells in long-term culture and to further study their differentiation in the absence of stroma, both in vitro and in vivo.     

Ultrasonographic nomograms of the fetal fourth ventricle: additional tool for detecting abnormalities of the posterior fossa.

OBJECTIVE: To characterize normal growth of the fetal fourth ventricle on ultrasonography throughout pregnancy. METHODS: Consecutive biometric measurements and fetal organ scans were obtained from 299 patients undergoing fetal anatomic surveys between 13 and 40 weeks' gestation. Using 7- and 3.5-MHz transducers for early (13- to 17-week) and late (>17-week) examinations, respectively, we scanned the fetal head in the axial plane with special focus on the posterior fossa of the brain. The fourth ventricle was identified, and its anteroposterior diameter and width were measured. A "triangle" formula was used for calculating its circumference and area. RESULTS: The fourth ventricle was shown as a hypoechoic triangle below the level of the cerebellum. A linear regression line of the fourth ventricle was observed across gestational age, and a first-degree correlation was found between gestational age and anteroposterior diameter of the fourth ventricle (r = 0.894; P < .0001; y = -0.84 + 0.23 x gestational age), its width (r = 0.657; P < .0001; y = 3.82 + 0.14 x gestational age), its circumference (r = 0.843; P < .0001; y = 5.11 + 0.58 x gestational age), and its area (r = 0.844; P < .0001; y = -10.11 + 1.17 x gestational age). Twelve enlarged fourth ventricles were found between 14 and 16 weeks, but results of follow-up scans at 20 weeks were normal. CONCLUSIONS: An isolated enlarged fourth ventricle in the early second trimester might represent a normal variant; it should be followed, but decisions about the fate of the pregnancy should not be based solely on this finding.     

The management of congenital and acquired problems of the distal radioulnar joint in children

Pain in the ulnar aspect of the pediatric wrist is an uncommon problem; however, when pain does occur it is usually the result of antecedent bony trauma or an underlying skeletal abnormality, which may lead to ulnar-sided wrist pain of varying etiology. The clinician must to be able to identify these entities within the pediatric wrist in order to make the appropriate diagnosis and plan for surgical intervention to prevent ongoing damage to the distal radioulnar joint (DRUJ). This article reviews the etiology, clinical presentation, and treatment strategies for the management of the unique problems that can affect the pediatric and adolescent DRUJ.     

Treatment of new-onset type 1 diabetes with peptide DiaPep277 is safe and associated with preserved beta-cell function: extension of a randomized, double-blind, phase II trial

BACKGROUND: Treatment with DiaPep277, a peptide derived from HSP60, has been shown to preserve beta-cell function in non-obese diabetic mouse (NOD) mice and in a trial with newly diagnosed human patients with type 1 diabetes treated over a 10-month period. This article extends the clinical trial observations to a total of 20 months of treatment to determine the safety and the effects of repeated doses of DiaPep277 on endogenous insulin secretion, metabolic control, and exogenous insulin requirements. METHODS: Thirty-five male patients (aged 16-58) with a basal C-peptide greater than 0.1 nmol/L were assigned to periodic treatment with DiaPep277 (1 mg) or placebo for a 12-month treatment and 18-month observation protocol, later extended to an additional year of treatment. Stimulated C-peptide, HbA1c, and an exogenous insulin dose were the clinical endpoints. RESULTS: At 18 months, stimulated C-peptide concentrations had fallen in the placebo group (p = 0.0005) but were maintained in the DiaPep277 group. The need for exogenous insulin was higher in the placebo group than in the DiaPep277 group. Mean HbA1c concentrations were similar in both groups. After extension of the study, patients continuing treatment with DiaPep277 and those switched from placebo to DiaPep277 manifested a trend towards a greater preservation of beta-cell function compared to patients maintained on or switched to placebo. The safety profile of DiaPep277 was similar between the treatment and placebo groups, and no drug-related adverse events occurred. CONCLUSIONS: Periodic treatment of subjects with DiaPep277 over 2 years was safe and associated preservation of endogenous insulin secretion up to 18 months was observed.     

Heat-shock protein peptide DiaPep277 treatment in children with newly diagnosed type 1 diabetes: a randomised, double-blind phase II study

BACKGROUND: Type 1 diabetes mellitus (T1DM) is a T-cell-mediated autoimmune disease that leads to the destruction of insulin-producing beta cells. Treatment with DiaPep277, a peptide derived from heat-shock protein 60 (hsp60), has been found to slow the deterioration of beta-cell function after clinical onset of diabetes in NOD mice and human adults. Our aim was to evaluate the efficacy and safety of DiaPep277 treatment in attenuating beta-cell destruction in children with recent-onset T1DM. METHODS: A prospective, randomized, double-blind, phase II design was used. The sample included 30 children (19 males) aged 7-14 years who had been diagnosed with T1DM from 53 to 116 days previously, and had basal C-peptide concentrations above 0.1 nmol/L. The children were randomized to receive subcutaneous injections of 1 mg DiaPep277 (15 patients) or 40 mg mannitol (placebo) at entry and at 1, 6, and 12 months. The duration of follow-up was 18 months. The groups were compared for stimulated C-peptide level, exogenous insulin dose, and HbA1c concentration. RESULTS: C-peptide levels similarly decreased over time in the DiaPep277- and placebo-treated patients. There was no significant difference in insulin dose or HbA1c concentration between the groups at any time point. No serious drug-related adverse effects were recorded throughout the study period. CONCLUSIONS: One-year treatment with DiaPep277 at a dosage of 1 mg is safe for use and well tolerated in children with recent-onset T1DM. However, it appears to have no beneficial effect in preserving beta-cell function or improving metabolic control.     

A dual role for interleukin-1 in hippocampal-dependent memory processes

Ample research demonstrates that pathophysiological levels of the pro-inflammatory cytokine interleukin-1 (IL-1) produces detrimental effects on memory functioning. However, recent evidence suggests that IL-1 may be required for the normal physiological regulation of hippocampal-dependent memory. To substantiate the physiological role of IL-1 in learning and memory we examined the induction of IL-1 gene expression following a learning experience, and the effects of IL-1 signaling blockade, by either genetic or pharmacological manipulations, on memory functioning. We show that IL-1 gene expression is induced in the hippocampus 24h following fear-conditioning in wild type mice, but not in two mouse strains with impaired IL-1 signaling. Moreover, we report that mice with transgenic over-expression of IL-1 receptor antagonist restricted to the CNS (IL-1raTG) display impaired hippocampal-dependent and intact hippocampal-independent memory in the water maze and fear-conditioning paradigms. We further demonstrate that continuous administration of IL-1ra via osmotic minipumps during prenatal development disrupt memory performance in adult mice, suggesting that IL-1 plays a critical role not only in the formation of hippocampal-dependent memory but also in normal hippocampal development. Finally, we tested the dual role of IL-1 in memory by intracerebroventricular (ICV) administration of different doses of IL-1beta and IL-1ra following learning, providing the first systematic evidence that the involvement of IL-1 in hippocampal-dependent memory follows an inverted U-shaped pattern, i.e., a slight increase in brain IL-1 levels can improve memory, whereas any deviation from the physiological range, either by excess elevation in IL-1 levels or by blockade of IL-1 signaling, results in impaired memory.     

EUS-guided FNA diagnostic yield of malignancy in solid pancreatic masses: a benchmark for quality performance measurement

BACKGROUND: The diagnostic yield of EUS-guided FNA (EUS-FNA) of solid pancreatic masses is a potential benchmark for EUS-FNA quality, because the majority of EUS-FNA of solid pancreatic masses should be diagnostic for malignancy. OBJECTIVES: To determine the cytologic diagnostic rate of malignancy in EUS-FNA of solid pancreatic masses and to determine if variability exists among endoscopists and centers. DESIGN: Multicenter retrospective study. PATIENTS: EUS centers provided cytology reports for all EUS-FNAs of solid, noncystic, >or=10-mm-diameter, solid pancreatic masses during a 1-year period. MAIN OUTCOME MEASUREMENT: Cytology diagnostic of pancreatic malignancy. RESULTS: A total of 1075 patients underwent EUS-FNA at 21 centers (81% academic) with 41 endoscopists. The median number of EUS-FNA of solid pancreatic masses performed during the year per center was 46 (range, 4-177) and per endoscopist was 19 (range, 1-97). The mean mass dimensions were 32 x 27 mm, with 73% located in the head. The mean number of passes was 3.5. Of the centers, 90% used immediate cytologic evaluation. The overall diagnostic rate of malignancy was 71%, 95% confidence interval 0.69%-0.74%, with 5% suspicious for malignancy, 6% atypical cells, and 18% negative for malignancy. The median diagnostic rate per center was 78% (range, 39%-93%; 1st quartile, 61%) and per endoscopist was 75% (range, 0%-100%; 1st quartile, 52%). LIMITATIONS: Retrospective study, participation bias, and varying chronic pancreatitis prevalence. CONCLUSIONS: (1) EUS-FNA cytology was diagnostic of malignancy in 71% of solid pancreatic masses and (2) endoscopists with a final cytologic diagnosis rate of malignancy for EUS-FNA of solid masses that was less than 52% were in the lowest quartile and should evaluate reasons for their low yield.     

Concerted ATP-induced allosteric transitions in GroEL facilitate release of protein substrate domains in an all-or-none manner

The double-ring chaperonin GroEL mediates protein folding, in conjunction with its helper protein GroES, by undergoing ATP-induced conformational changes that are concerted within each heptameric ring. Here we have examined whether the concerted nature of these transitions is responsible for protein substrate release in an all-or-none manner. Two chimeric substrates were designed, each with two different reporter activities that were recovered after denaturation in GroES-dependent and independent fashions, respectively. The refolding of the chimeras was monitored in the presence of GroEL variants that undergo ATP-induced intraring conformational changes that are either sequential (F44W/D155A) or concerted (F44W). Our results show that release of a protein substrate from GroEL in a domain-by-domain fashion is favored when the intraring allosteric transitions of GroEL are sequential and not concerted.