Ultrastructure of the spermatozoid in Halimeda tuna (chlorophyceae)

The mature Halimeda tuna spermatozoid was studied under the electron microscope. It is pear-shaped and biflagellate. The nucleus is an uncondensed structure except for a few opaque (chromatin) aggregations and shows a rounded profile. The endoplasmic reticulum is a rather well-developed system of rough cisternae engaged in synthesis and storage of proteins. Free ribosomes are numerous. A large mitochondrial apparatus shaped like a horseshoe lies in the anterior gamete region. Only one single plastid is found, and it exhibits a deeply indented outline, a partially structured matrix, osmiophilic globules, and three to four starch grains. The axoneme pattern is 9 + 2. B tubules show septate lumina. A peculiar structure provided with a three-layered shell covering materials of varying electrondensity lies on the upper surface of both basal bodies. The flagellar root system exhibits a cruciate pattern and sets having an inconstant number of microtubules – ie, three, four, or five.     

Biological monitoring of exposure to n-heptane by gas chromatographic mass spectrometric determination of its metabolites

Urine samples from 10 workers that had been exposed to n-heptane were analysed by the GC/MS technique to verify the concentrations and the relative abundances of its metabolites. The procedure of sample preparation has undergone some modifications with respect to the Perbellini method and the mass spectrometric detection was carried out in selected ions monitoring conditions. The analyses of samples collected during three different workshifts showed that 2 heptanol was not the main metabolite and that the remains of 2 heptanone, valerolactone and 2,5 heptanedione were present at the beginning of the successive work week at 12, 34 and 39 of the average values found at the end of the previous week. Overall, a very slow excretion rate was detected for the last metabolite. The main and significant metabolite at the end of the two workshifts was 2 heptanone which was detected in urine at average values of 413 and 238 μg g^-1 creatinine. This urinary ketone correlated better than other metabolites with respect to the airborne n-heptane at the end of both the workshift and work week. These preliminary data suggest that further studies should be carried out to confirm whether 2 heptanone is really useful as an n-heptane marker in biological monitoring.     

THE EVOLUTION OF FEMALE BODY SIZE IN RED-WINGED BLACKBIRDS: THE EFFECTS OF TIMING OF BREEDING,SOCIAL COMPETITION,AND REPRODUCTIVE ENERGETICS

We examined opposing selective forces on female body size in the sexually dimorphic red-winged blackbird: social competition favoring larger females, and energetic advantages favoring smaller females. Downhower proposed that selection might drive female birds to be smaller than the optimum for survival, if smaller females were able to exceed their energetic requirements for self-maintenance earlier in the season and therefore breed earlier. Since in most birds the earliest breeders fledge the most young, this could favor the evolution of smaller female size, and therefore contribute to the magnitude of sexual size dimorphism in these birds. We tested this hypothesis in 1987 and 1988 by comparing the size and breeding date of female red-winged blackbirds. Consistent with our preditions, early-nesting females had much higher nesting success, but contrary to prediction, larger females bred earlier. We then examined the effects of female size on competition. If large females have an advantage in social competition, and if competition influences breeding date and reproductive success, then larger females might breed earlier. Primary females, the first females to arrive and nest on a territory, were more aggressive than lower ranked females; more aggressive females settled on better territories and laid earlier than less aggressive females; and larger females were more aggressive. Social competition between females may therefore favor large females. Finally, we tested the prediction that selection favoring large females might be limited by energetic constraints on large females. We found that large females had less fat than small females during breeding, and that the levels of fat that females of a given size carried affected breeding date and egg size. Therefore, social competition may favor large females, but reproductive energetics favoring smaller females may constrain selection for large female body size.     

Molecular dynamics calculations on peroxidases: the effect of calcium ions on protein structure

 Molecular dynamics (MD) calculations were performed on two peroxidases, lignin peroxidase (LiP) and horseradish peroxidase (HRP), in the presence of the two endogenous calcium ions. The resulting averaged structures were compared to the structures obtained in the absence of the calcium ions. The overall protein folding was not affected by the presence or the lack of the calcium ions, while the active site was perturbed. In particular, on the distal side, a sizeable rearrangement of the distal histidine was observed in the absence of the calcium ions. These structural rearrangements are critically discussed with respect to the enzymatic mechanism. Received: 15 November 1995 / Accepted: 1 March 1996     

Clinical Applicability of Patient- and Clinician-Reported Outcome Tools in the Management of Patients With Acromegaly

ObjectiveWe aimed to assess treatment outcomes and disease control status in patients with acromegaly using patient- and clinician-reported outcome tools and to analyze correlations among different components of both tools.MethodsThis cross-sectional study included 72 patients from a national referral center with a median follow-up of 8 (5-12) years. The baseline SAGIT score at diagnosis was determined retrospectively, whereas the follow-up SAGIT and acromegaly quality of life questionnaire (AcroQoL) results were assessed at the most recent visit and by additional telephone interviews.ResultsAll SAGIT subscores decreased significantly from baseline to follow-up (global score from 14 to 4 [P < .001]). The SAGIT scores at baseline did not discriminate the current disease control status. However, a higher baseline SAGIT score and subscore T were associated with uncontrolled disease after the first-line treatment. Diagnostic delay was correlated with baseline S, A, G, and global SAGIT scores. At the follow-up, the global SAGIT score discriminated between cured/controlled and uncontrolled groups (4 vs 6 [P = .007]). The AcroQoL score was 69.3, with the personal relations subscale being the least affected and the physical scale being the most affected. There was no difference in the AcroQoL score between patients classified as uncontrolled or cured/controlled. At baseline and follow-up, there were significant negative correlations between S and A subscores and AcroQoL score. A higher body mass index, the presence of swelling, joint symptoms, headaches, sleep apnea, and hypertension significantly impaired quality of life.ConclusionOur results emphasize the complementary nature of the patient- and clinician-reported outcome tools in acromegaly management. We identified modifiable signs, symptoms, and comorbidities as treatment targets that might help clinicians improve quality of life in this population.