Causes of B chromosome variant substitution in the grasshopper Eyprepocnemis plorans

We have analysed B chromosome frequency for three consecutive years, B transmission rate at population and individual levels, clutch size, egg fertility and embryo–adult viability in a natural population of the grasshopper Eyprepocnemis plorans containing two different B chromosome variants, i.e. B₂ and B₂₄, the second being derived from the first and having replaced it in nearby populations. From 2002 to 2003 the relative frequency of both variants changed, although the differences did not reach significance. A mother–offspring analysis showed no significant effect of any of the two B variants on clutch size, egg fertility or embryo–adult viability, but B₂₄ was more efficiently transmitted than B₂ through males from the 2002 season, which explains the observed frequency change. Controlled crosses, at individual level, showed significant drive through some females for B₂₄ but not for B₂, suggesting that this difference in transmission rate might also be important for the substitution process. The analysis of relative fitness for B₂ and B₂₄ carriers for all fitness components, as a whole, showed a significantly better performance of B₂₄-carrying individuals, suggesting that the cumulative effect of these slight differences might contribute to the replacement of B₂ by B₂₄. Electronic Supplementary Material Supplementary material is available for this article at .     

Relative weight of glucose, insulin and parathyroid hormone in the urinary loss of phosphate by chronically diabetic rats

This report deals with the relationships between glucose (G) and insulin on the tubular transport of phosphate (P) in chronically diabetic rats with high plasma levels of parathyroid hormone (PTH). Alloxan-induced diabetes leads to phosphorus depletion of the soft tissues. This phenomenon appears associated with weight loss and negative P balances caused by the increased urinary P excretion. Administration of 2 IU of insulin/100 g body weight (bw) to diabetic rats normalized their P balance and body weight. The effect of parathyroid function on the P metabolism of diabetic rats was investigated with balance experiments. Diabetic rats, intact or thyroparathyroidectomized (TPTX), have a greater urinary excretion of P than their controls. However, in control rats, the ratio intact:TPTX for urinary P is 1.0:0.76, showing the antiphosphaturic effect of parathyroid ablation. For diabetic animals, on the other hand, the ratio is 1.0:1.44. The simultaneous deficit of insulin and PTH thus quadruples the urinary P loss, instead of compensating for each other. The contribution of insulin deficit and hyperglycemia to the defect in tubular reabsorption (TRP) was investigated with clearance experiments (done on anesthetized, perfused rats). Five experimental groups were used: Controls (C), diabetics (D), controls+glucose (C+G), diabetics+insulin (D+I) and diabetics+insulin+glucose (D+I+G). All experimental groups showed a linear relationship between the TRP of P and G. The regression equation for C is significantly different (F=40.1, P<0.001) from that of D animals. The slope value measure the number of μmoles of P per μmol of G reabsorbed. For C and D rats, the ratio P:G approximates 1:4 and 1:20, respectively. The increase in P:G ratios represents the competition between both substrates for tubular resorption. Glycemias up to 11 mM (C and D+I) exist concurrent with the P:G ratio 1:4. Glycemias above 25 mM (D, C+G and D+I+G) produce a P:G ratio of 1:20. Fractional excretion of P (FEP) increased significantly in untreated, chronically diabetic rats (0.47± 0.12 vs controls=0.05±0.01, P<0.001). After a single intramuscular injection of insulin, the FEP decreased as a function of insulin levels. To normalize the FEP of diabetic rats in short-term experiments, insulin had to be administered in doses that produce plasma insulin levels 25 times greater than normal. The general information afforded by the present experiments shows that in untreated, chronically diabetic rats, insulin deficit plays an indirect role. The absence of PTH enhances the effect of hyperglycemia. The latter and the concurrent tubular overload of glucose are the cause of hyperphosphaturia in these animals. Received: 10 September 1996 / Accepted in revised form: 18 April 1997     

Evidence that non-NMDA receptors are involved in the excitatory pathway from the pedunculopontine region to nigrostriatal dopaminergic neurons

Summary Extracellular single-neuron recordings were obtained from electrophysiologically identified nigrostriatal neurons in chloral hydrate anesthetized rats, in order to test the hypothesis that excitatory amino acid receptors are involved in responses of these neurons to electrical stimulation of the pontine region where the pedunculopontine nucleus (PPN) is located. The effects of iontophoretic application of excitatory amino acids and their antagonists as well as of cholinergic antagonists were tested on the fast orthodromic excitation of nigrostriatal neurons evoked by stimulation of the PPN region. The N-methyl-D-aspartate (NMDA) receptor antagonist D-a-aminoadipic acid as well as the cholinergic receptor antagonists mecamylamine and atropine failed to suppress the synaptic excitation of nigral neurons. The NMDA receptor antagonist DL-2-amino-5-phosphonovalerate exerted a weak depressant action on the synaptic response in a few neurons only. On the contrary, the broad spectrum antagonists of excitatory amino acid receptors kynurenic acid and gamma-Dglutamyl-amino-methyl-sulphonate were found to block simultaneously both the synaptic excitation and the neuronal responses to iontophoretic pulses of glutamate while leaving unaffected the neuronal responses to local application of acetylcholine or carbachol. The competitive antagonist of non-NMDA receptors 6-cyano-2,3-dihy-droxy-7-nitro-quinoxaline suppressed the synaptic excitation at ejection currents which antagonized neuronal responses to quisqualate and kainate. These results suggest that PPN excitatory fibers synapsing onto pars compacta nigrostriatal neurons utilize an excitatory amino acid as a synaptic transmitter acting preferentially on non-NMDA receptors.     

B cell lymphoma of the thymus and salivary gland.

A case of primary low grade B cell lymphoma of the salivary gland associated with a low grade B cell lymphoma of the thymus and involvement of the skin is reported. The lesions in the salivary gland and in the thymus showed the typical features of a lymphoma arising from the mucosa associated lymphoid tissue (MALT) and comprised lymphatic follicles, centrocyte-like (CCL) cells and lymphoepithelial lesions. Immunohistochemistry and Southern blot analysis supported the hypothesis that these lesions can originate from the same cellular clone. These findings confirm the occurrence of low grade B cell MALT lymphoma in the thymus and the possibility of spread of MALT lymphoma to other mucosal sites.     

Image-guided core breast biopsy: a suitable method for preoperative biological characterization of small (pT1) breast carcinomas

Multiple prognostic indicators, namely histological grade and immunostaining for estrogen (ER) and progesterone receptors (PgR), MIB 1, bc1-2, and p53, were retrospectively determined on preoperative core biopsies from 75 patients with pT 1 breast carcinoma. The association of the preoperatively evaluated factors with those on the corresponding resected tumors (i.e. nodal status, histological grade, presence or absence of vascular invasion and necrosis) was assessed. In univariate analysis, histological grade on resected tumors was significantly associated with histological grade on core biopsy, p53 expression, MIB1 immunostaining. An inverse association was found between postoperative histologic grade and ER, PgR, and bc1-2. Necrosis was significantly associated with grade, p53, MIB1, and inversely with ER, PgR, and bc1-2. Nodal involvement and vascular invasion were significantly associated with MIB1. In multivariate analysis, histological grade and ER were the only independent core biopsy variables associated with postoperative histological grade and necrosis, respectively. This study showed that image-guided core biopsy is a suitable method that can be used to reveal some characteristics of the tumor biology in a preoperative stage.     

Impact of hepatitis C virus infection on clinical features, quality of life and survival of patients with lymphoplasmacytoid lymphoma/immunocytoma

Background: The non-Hodgkins lymphoma (NHL) subgroup most frequentlyassociated with hepatitis C virus (HCV) infection is the lymphoplasmacytoidlymphoma/immunocytoma (Lp-Ic). We have assessed the impact of the infectionon the clinical features, quality of life and survival of HCV+ve Lp-Icpatients as compared to its impact in HCV–ve patients.Patients and methods: Seventy patients with Lp-Ic consecutively observedover a six-year period were studied. Clinical, virological andhistopathological features were recorded at diagnosis. Quality of life wasassessed using a scoring system including disease-related symptoms,performance status, working ability, hospital admissions and therapiesrequired.Results: Eighteen patients (26%) with HCV infection wereidentified. Significant differences between those patients and theHCV–ve group included number of symptomatic patients, Hb levels, serumprotein levels, entity of the IgM monoclonal component, number of patientswith cryoglobulins and with organ (liver, kidney) involvement, and entityand pattern of bone marrow infiltration. Survival rates were similar (P =0.8383), but the quality-of-life score was significantly worse for theHCV+ve patients (P = 0.002). All anti-HCV Ab+ve patients tested positive forHCV RNA; genotype 2ac was detected in a significant proportion of cases.Conclusions: This study confirms that HCV infection is present in aboutone-third of patients with Lp-Ic. HCV infection does not seem to affect theoverall survival of patients with Lp-Ic, but it affects the clinicalexpression of the disease, so that the overall quality of life of HCV+vepatients is significantly worse.     

Systemic review of trials on the use of tramadol in the treatment of acute and chronic pain

BACKGROUND: The purpose of the study was to verify the effectiveness of tramadol in the treatment of non-oncologic chronic pain, oncologic chronic pain and postoperative acute pain, applying the principles of meta-analytic analysis to randomized clinical trials (TCR). METHODS: I: Medline research of the TCR on the question in the period between 1989-1999, II: exclusion of single TCR through the question of Moore and Mcquay; calculation of the relative risk reduction (RRR), of the number needed to treat (NNT), of the odds ratio (OR) and of the typical odds ratio (TOR) of the trials which responded to characteristics of correct randomization and blindness, which expressed citation of the patients excluded from trial, and patients with measurable analgesic effectiveness (number of patients with reduction of the pain intensity 50%). RESULTS: 52 trials extracted from Medline: 10 on the treatment of non-oncologic chronic pain, 36 on the treatment of postoperative acute pain and 6 on the treatment of oncologic chronic pain. Responded fully to requirements: 8 studies (3 for non-oncologic chronic pain, 3 for postoperative acute pain and 2 for oncologic pain). The OR was 0.55 (-0.31/1.41); 0.44 (1.04/1.92) and 0.98 (0.5/1.46); the RRR was 0.26 (-0.19/0.71), 0.38 (0.15/0.61), 0.005 (0.19/0.20) and the NNT 6.6 (6.39/6.81), 5.26 (5.12/5.4), infinity in the 3 trials selected between those that concern the treatment of the nononcologic chronic pain (with TOR: 0.57 and confidence index: 0.23-0.9); the OR was 0.36 (1.06/1.78), 0.78 (-0.08/-1.64) and 1.12 (0.54/1.69); the RRR was 0.26 (-0.18/0.7), 0.07 (-0.2/0.35), -0.01 (-0.09/0.07) and the NNT 4.7 (4.42/4.58), 20 (19.8/20.20), infinity in the trials on the treatment of postoperative acute pain (with TOR: 0.4 and confidence index: -0.6-0.86); the OR was 0.53 (-0.67/1.73), 0.27 (-0.71/1.12); the RRR was 0.19 (-0.33/0.72), 0.35 (0.02/0.68) and the NNT 7.1 (6.78/7.42), 3.57 (3.37/3.76) in those that involved the treatment of oncologic chronic pain (with TOR: 0.49 and confidence index: 0.36-0.8). CONCLUSIONS: Although the short number of trials which can treated by the metanalytic technique the treatment with tramadol, compared comparison's to drugs (morphine, pentazocine, bupremorphine, etc.) determined a slight improvement in analgesic parameters or at least in analgesic effectiveness.