Fate of afferents to the dentate gyrus following destruction of granule cells with colchicine

Granule cells of the dentate gyrus can be selectively destroyed by intrahippocampal injections of colchicine. The present study evaluates the consequences of this selective neuronal destruction on the afferent axon terminals which have been deprived of their normal targets. The area of the neuropil in the dentate gyrus (the molecular layer) was evaluated in sections stained using the Timm's method for heavy metals, which selectively marks the terminal fields of the different afferent systems. The molecular layer was examined electron microscopically to determine the fate of afferent terminals. Anterograde transport of HRP or [3H]proline was used to define the location and extent of afferent terminal fields of the entorhinal and commissural projections to the dentate gyrus in which the granule cells had been destroyed. There was a substantial reduction in the size of the dentate gyrus molecular layer after destruction of granule cells with colchicine. Electron microscopic analyses revealed that there were very few axon terminals or synapses remaining in the shrunken molecular layer. Tract tracing methods revealed that both the entorhinal and commissural pathways were still present in their normal terminal zones in the dentate gyrus, however, the density of the projections was greatly reduced. There was no evidence to suggest the formation of ectopic projections to unusual locations, such as the contralateral dentate gyrus. Pathways passing through the hippocampus appeared to survive the colchicine injections. These results suggest that target destruction in adult animals leads to the disappearance of the afferent axon terminals which normally innervate the cells which die.     

[125I] N6-p-hydroxyphenylisopropyladenosine,a new ligand for Ri adenosine receptors

Summary N⁶-p-Hydroxyphenylisopropyladenosine (HPIA) has been labelled with carrier-free Na[¹²⁵I] to very high specific activity (2,175 Ci/mmol) and used as an agonist ligand to characterize R_i adenosine receptors in rat cerebral cortex membranes. The binding is saturable, reversible, stereospecific and dependent on protein concentration. The specific binding at 37°C was of high affinity with an equilibrium dissociation constant K_D of 0.48 nmol/l and was saturable with 0.23 pmol of [¹²⁵I]HPIA per mg of protein. The rate constant of association, k₁, was 3.25×10⁸ l mol^–1 min^–1 and that of dissociation, k₂, 0.0110 min^–1 yielding a t_1/2 of 63 min. In competition experiments the (–)isomer of N⁶-phenylisopropyladenosine (PIA) was 16-fold more potent than the (+)isomer in competing for the binding sites. Specific binding was most effectively displaced by N⁶-cyclohexyladenosine (CHA, k_i=0.26 nmol/l), (–)PIA (k_i=0.33 nmol/l) and HPIA (k_i=0.52 nmol/l), whereas 5-N-ethylcarboxamidoadenosine (NECA, k_i-1.42 nmol/l) was less effective. The methylxanthines 3-isobutyl-1-methylxanthine (IBMX), theophylline and caffeine which have been classified as adenosine antagonists had k_i values between 5–34 mol/l. Binding of [¹²⁵I]HPIA was regulated by guanine nucleotides and divalent cations. The results indicate that [¹²⁵I]HPIA labels R_i adenosine receptors in rat brain membranes.     

Primary metastatic osteosarcoma: presentation and outcome of patients treated on neoadjuvant Cooperative Osteosarcoma Study Group protocols.

PURPOSE: To determine demographic data and define prognostic factors for long-term outcome in patients presenting with high-grade osteosarcoma of bone with clinically detectable metastases at initial presentation. PATIENTS AND METHODS: Of 1,765 patients with newly diagnosed, previously untreated high-grade osteosarcomas of bone registered in the neoadjuvant Cooperative Osteosarcoma Study Group studies before 1999, 202 patients (11.4%) had proven metastases at diagnosis and therefore were enrolled onto an analysis of demographic-, tumor-, and treatment-related variables, response, and survival. The intended therapeutic strategy included pre- and postoperative multiagent chemotherapy as well as aggressive surgery of all resectable lesions. RESULTS: With a median follow-up of 1.9 years (5.5 years for survivors), 60 patients were alive, 37 of whom were in continuously complete surgical remission. Actuarial overall survival rates at 5 and 10 (same value for 15) years were 29% (SE = 3%) and 24% (SE = 4%), respectively. In univariate analysis, survival was significantly correlated with patient age, site of the primary tumor, number and location of metastases, number of involved organ systems, histologic response of the primary tumor to preoperative chemotherapy, and completeness and time point of surgical resection of all tumor sites. However, after multivariate Cox regression analysis, only multiple metastases at diagnosis (relative hazard rate [RHR] = 2.3) and macroscopically incomplete surgical resection (RHR = 2.4) remained significantly associated with inferior outcomes. CONCLUSION: The number of metastases at diagnosis and the completeness of surgical resection of all clinically detected tumor sites are of independent prognostic value in patients with proven primary metastatic osteosarcoma.     

Effect of acupuncture compared with placebo-acupuncture at P6 as additional antiemetic prophylaxis in high-dose chemotherapy and autologous peripheral blood stem cell transplantation: a randomized controlled single-blind trial.

PURPOSE: The purpose is to investigate an additional antiemetic effect to ondansetron with needle acupuncture at P6 compared with nonskin-penetrating placebo acupuncture in patients undergoing high-dose chemotherapy and autologous peripheral blood stem cell transplantation. EXPERIMENTAL DESIGN: Eighty patients who were admitted to hospital for high-dose chemotherapy and autologous peripheral blood stem cell transplantation were included into a randomized placebo-controlled single-blind trial. The patients were randomized to receive acupuncture (n = 41) or noninvasive placebo acupuncture (n = 39) at the acupuncture point P6 30 min before first application of high-dose chemotherapy and the day after. All patients received 8 mg ondansetron/day i.v. as basic antiemetic prophylaxis. The main outcome measure was the rate of patients who either had at least one episode of vomiting or required any additional antiemetic drugs on the first 2 days of chemotherapy. RESULTS: The main outcome measure showed no significant difference (P = 0.82): 61% failure in the acupuncture group and 64% in the placebo acupuncture group (95% confidence interval of 3% difference: -18.1 and 24.3%). Comparing nausea, episodes of vomiting or retching and number of additionally required antiemetic drugs did not provide any discrepancy with the main result. CONCLUSIONS: This study suggests that in combination with ondansetron i.v., invasive needle acupuncture at P6 compared with nonskin-penetrating placebo acupuncture has no additional effect for the prevention of acute nausea and vomiting in high-dose chemotherapy.     

Morphologic dysplasia in de novo acute myeloid leukemia (AML) is related to unfavorable cytogenetics but has no independent prognostic relevance under the conditions of intensive induction therapy: results of a multiparameter analysis from the German AML Cooperative Group studies.

PURPOSE: On the basis of cytomorphology according to the French-American-British (FAB) classification, we evaluated the prognostic impact of dysplastic features and other parameters in de novo acute myeloid leukemia (AML). We also assessed the clinical significance of the recently introduced World Health Organization (WHO) classification for AML, which proposed dysplasia as a new parameter for classification. PATIENTS AND METHODS: We analyzed prospectively 614 patients with de novo AML, all of whom were diagnosed by central morphologic analysis and treated within the German AML Cooperative Group (AMLCG)-92 or the AMLCG-acute promyalocytic leukemia study. RESULTS: Patients with AML M3, M3v, or M4eo demonstrated a better outcome compared with all other FAB subtypes (P <.001); no prognostic difference was observed among other FAB subtypes. The presence or absence of dysplasia failed to demonstrate prognostic relevance. Other prognostic markers, such as age, cytogenetics, presence of Auer rods, and lactate dehydrogenase (LDH) level at diagnosis, all showed significant impact on overall and event-free survival in univariate analyses (P <.001 for all parameters tested). However, in a multivariate analysis, only cytogenetics (unfavorable or favorable), age, and high LDH maintained their prognostic impact. Dysplasia was not found to be an independent prognostic parameter, but the detection of trilineage dysplasia correlated with unfavorable cytogenetics. CONCLUSION: Our results indicate that cytomorphology and classification according to FAB criteria are still necessary for the diagnosis of AML but have no relevance for prognosis in addition to cytogenetics. Our results suggest that the WHO classification should be further developed by using cytogenetics as the main determinant of biology. Dysplastic features, in particular, have no additional impact on predicting prognosis when cytogenetics are taken into account.     

The association between two common mutations C677T and A1298C in human methylenetetrahydrofolate reductase gene and the risk for diabetic nephropathy in type II diabetic patients

Mutations of the methylenetetrahydrofolate reductase (MTHFR) gene have been shown to be associated with a predisposition to developing diabetic nephropathy (DN) in specific populations. The frequency of two MTHFR mutations, a recently described mutation in the human MTHFR gene A1298C and C677T, whose association with DN is already known, was determined in an Israeli Jewish population with type 2 diabetes mellitus (DM). Both A1298C and C677T are highly prevalent in the diabetic population with allele frequencies of 0.35 and 0.36, respectively. The genotype frequency and allele frequency for these two polymorphisms in patients who are normoalbuminuric (n = 55) were compared with those of patients who had either micro- or macroalbuminuria (n = 43). For both polymorphisms, there were no significant differences in either the genotype distribution or allele frequency in patients with or without DN. However, in patients with serum folate <15.4 nmol/L, there was a greater incidence of DN in those patients who were homozygous or heterozygous for the C677T mutation. For the A1298C mutation, there is evidence suggesting that the homozygous state may be protective in patients with low-normal serum folate. Folate supplementation in diabetic patients with the C677T mutation and low-normal serum folate may prevent the onset or retard the progression of DN.     

Flat-panel volume computed tomography for cochlear implant electrode array examination in isolated temporal bone specimens.

HYPOTHESIS: Flat-panel based volume computed tomography could improve cochlear implant electrode evaluation in comparison with multislice computed tomography. BACKGROUND: Flat-panel based volume computed tomography offers higher spatial resolution and less metal artifacts than multislice computed tomography. Both characteristics could improve the evaluation of challenging but important questions in cochlear implantation assessment, such as an exact imaging of cochlea, osseous spiral lamina, electrode array position, and single electrode contacts. These questions are not currently fully answered by multislice computed tomography. METHODS: Four isolated temporal bone specimens were scanned in a current multislice computed tomography scanner and in two experimental flat-panel based volume computed tomography scanners before and after cochlea implantation. To compare flat-panel based volume computed tomography and multislice computed tomography, four features were rated according to the following criteria: 1) visibility of the cochlea; 2) visibility of the osseous spiral lamina; 3) discernibility of individual electrode contacts; and 4) the ability to determine the electrode array position relative to scala tympani and scala vestibuli. Layer-by-layer microgrinding pictures were used as the ground truth for verification of imaging findings. RESULTS: Flat-panel based volume computed tomography was superior to multislice computed tomography in all four features rated. The cochlea and facial nerve canal were much better delineated in flat-panel based volume computed tomography. The osseous spiral lamina and single electrode contacts were only visible in flat-panel based volume computed tomography. Assessment of implant position with regard to the cochlear spaces was considerably improved by flat-panel based volume computed tomography. CONCLUSION: Cochlear implantation assessment could be improved by flat-panel based volume computed tomography and, therefore, would be highly beneficial for cochlea implantation research and for clinical evaluation. However, these first results were shown by scanning isolated temporal bone specimens; scanning whole human skull bases might be more challenging.     

Molecular monitoring of tumour load kinetics predicts disease progression after non-myeloablative allogeneic stem cell transplantation in multiple myeloma.

BACKGROUND: Non-myeloablative allogeneic stem cell transplantation followed by immunomodulatory therapies is considered a potentially curative approach in the treatment of multiple myeloma and most effective in a minimal residual disease setting. PATIENTS AND METHODS: The aim of this study was to find the most sensitive real-time PCR assay (TaqMan), based on the IGH rearrangement, to quantify the tumour load of 11 patients with multiple myeloma after non-myeloablative allogeneic transplantation. Patient-allele specific primers (ASO) and the TaqMan probe were derived from CDR2 and CDR3 hypervariable regions of IGH, while consensus primers were located within the FR3 and FR4/JH regions. Four different approaches of primer combinations were tested. RESULTS: ASO-forward and -reverse primers together with the clone-specific TaqMan probe were the most sensitive approach compared with the JH (P=0.071) or the FR3 consensus primer (P <0.001). The detection limit amounted to 1/10(4)-1/10(5) cells. Consecutively, 120 samples from 11 patients prior and post allogeneic transplantation were analysed. Three patients reached complete clinical remission accompanied by molecular remission. Disease progression or relapse was seen in six patients. In five, molecular progressive disease was detected prior to the clinical diagnosis of progression or relapse. CONCLUSION: Patient-specific real-time IGH-PCR provides the opportunity for earlier treatment intervention.     

Fludarabine in combination with alemtuzumab is effective and feasible in patients with relapsed or refractory B-cell chronic lymphocytic leukemia: results of a phase II trial.

PURPOSE: To determine the efficacy and safety of a newly developed concomitant administration of fludarabine and alemtuzumab (FluCam) in patients with relapsed or refractory B-cell chronic lymphocytic leukemia (B-CLL). PATIENTS AND METHODS: A total of 36 patients were treated in this phase II study (median age, 61.47 years; mean number of prior chemotherapies, 2.6; Binet stage C, n = 28). After an initial dose escalation of alemtuzumab over 3 days, alemtuzumab 30 mg and fludarabine 30 mg/m2 were administered on 3 consecutive days. Treatment was repeated after 28 days for up to six cycles. Restaging (following National Cancer Institute criteria) was carried out after cycles 2 and 4 and 1 month after the end of treatment. RESULTS: The overall response rate was 83% (11 complete responses, 19 partial responses, one stable disease, and five progressive diseases). Two patients with progressive disease developed fungal pneumonias, and one patient died as a result of Escherichia coli sepsis. Two subclinical cytomegalovirus reactivations occurred. CONCLUSION: The new FluCam regimen is effective and feasible in patients with relapsed and refractory B-CLL.