The reproductive strategy of the gregarious parasitoid,Pteromalus puparum (Hymenoptera: Pteromalidae)

Summary Pteromalus puparum is a gregarious parasitoid of many butterfly pupae. Adult size, mortality, and sex ratio of P. puparum, as a parasitoid of Papilio xuthus, were unit weight of the host. Effects of female size on fecundity, wing load, and longevity were also examined.The highest total weight of progeny from the host was attained when the number of eggs per gram of the host was approximately 150. Positive correlations were observed between the size of the females and their fecundity and wing load. The maximum longevity of the female kept with honey but without hosts was attained when the initial number of parasitoids per g of the host was 150.Considering the total fecundity of all female progeny, the reproductively most efficient number of eggs to be deposited per g of the host was estimated to be approximately 300. However, as shortage of food for the adult females strongly affects their fecundity, the reproductively most efficient number of eggs to be deposited per g of the host was about 70 when the adult female progeny was not provided with food.The optimal number of eggs to be deposited when the emale oviposits in the host under field conditions is discussed.     

Effect of detergent on protein structure. Action of detergents on secondary and oligomeric structures of band 3 from bovine erythrocyte membranes

With special interest in the mode of action of zwitterionic detergents on proteins, a variety of detergents were examined for their ability to disrupt the secondary and quaternary structures of an anion transport protein, band 3, and its cytoplasmic 38 kDa fragment from bovine erythrocyte membranes and for their effect on the binding of an anion transport inhibitor to band 3. Nonionic detergents and Chaps also acted as a nondenaturant in these instances, as well accepted for other proteins. Though deoxycholate and cholate inhibited the binding of an anion transport inhibitor to band 3, these detergents did not show any effect on the native structure of band 3. Zwitterionic detergents (Zwittergent 3-10, Zwittergent 3-12 and N, N-dimethyl-N-dodecyl glycine) were suggested to denature the water-soluble 38 kDa fragment at concentrations above the critical micelle concentration, but to be weak in disrupting interacting forces between hydrophobic membrane-bound domains of band 3. The results indicated that these zwitterionic detergents are similar in the mode of denaturing action to dodecyltrimethylammonium bromide rather than sodium dodecyl sulfate.     

Hyperthermic treatment of chromomycosis with disposable chemical pocket warmers

A case of chromomycosis in which hyperthermia proved effective is reported. The patient was a 56-year-old male bean curd maker who, without any previous history of minor trauma, developed on the extensor side of the left upper arm an eczematous lesion that underwent gradual radial expansion. The lesion showed a well-defined, 7×10 cm infiltrated erythematous plaque with the central area healed and, at the upper and lower borders, adherent scales and crusts on the surface. Histological examination revealed granulomatous changes in the dermis, as well as sclerotic cells within giant cells and microabscesses. On culturing,Fonsecaea pedrosoi was isolated. The patient was treated with disposable chemical pocket warmers, which were secured over the lesion with a rather tight elastic bandage, so that they kept the affected area warm for 24 hours a day. After a month of such hyperthermic treatment, the erythema and infiltration had decreased considerably, and microscopic examination and culture of the crusts both yielded negative results. Examination of biopsy specimens of the lesion after the third month showed that it had cicatrized. The treatment was stopped after 4 months, and no relapse occurred. We also summarize the published results of local hyperthermic treatment of chromomycosis in Japan.     

The Amusic Brain: Lost in Music,but Not in Space

Congenital amusia is a neurogenetic disorder of music processing that is currently ascribed to a deficit in pitch processing. A recent study challenges this view and claims the disorder might arise as a consequence of a general spatial-processing deficit. Here, we assessed spatial processing abilities in two independent samples of individuals with congenital amusia by using line bisection tasks (Experiment 1) and a mental rotation task (Experiment 2). Both amusics and controls showed the classical spatial effects on bisection performance and on mental rotation performance, and amusics and controls did not differ from each other. These results indicate that the neurocognitive impairment of congenital amusia does not affect the processing of space.     

Cloning and characterization of mouse klk27, a novel tissue kallikrein expressed in testicular Leydig cells and exhibiting chymotrypsin-like specificity.

A cDNA clone of a new mouse tissue kallikrein, designated mKlk27, was isolated from an adult mouse testis cDNA library. mKlk27 was expressed in the submaxillary glands and testis of the mouse. In testis, mKlk27 gene was expressed exclusively in the Leydig cells of the adult mouse. Active recombinant mKlk27 exhibited chymotrypsin-like cleavage specificity. A single amino-acid substitution of Gly for Asp at position 209 in mKlk27 resulted in complete loss of its chymotryptic activity but acquisition of tryptic activity. mKlk27 effectively hydrolyzed casein, gelatin and fibronectin. Insulin-like growth factor binding protein-3 was also hydrolyzed by recombinant mKlk27. These results suggest that mKlk27 plays an important role in association with the function of the adult mouse testis.     

Nucleotide binding sites and chemical modification of the chromaffin granule proton ATPase

The purified proton ATPase of chromaffin granules contains five different polypeptides denoted as subunits I to V in the order of decreasing molecular weights of 115,000, 72,000, 57,000, 39,000, and 17,000, respectively. The purified enzyme was reconstituted as a highly active proton pump, and the binding of N-ethylmaleimide and nucleotides to individual subunits was studied. N-Ethylmaleimide binds to subunits I, II, and IV, but inhibition of both ATPase and proton pumping activity correlated with binding to subunit II. In the presence of ADP, the saturation curve of ATP changed from hyperbolic to a sigmoid shape, suggesting that the proton ATPase is an allosteric enzyme. Upon illumination of the purified enzyme in the presence of micromolar concentrations of 8-azido-ATP, alpha-[35S]ATP, or alpha-[32P]ATP subunits I, II, and IV were labeled. However, at concentrations of alpha-[32P]ATP below 0.1 microM, subunit II was exclusively labeled in both the purified and reconstituted enzyme. This labeling was absolutely dependent on the presence of divalent cations, like Mg2+ and Mn2+, while Ca2+, Co2+, and Zn2+ had little or no effect. About 0.2 mM Mg2+ was required to saturate the reaction even in the presence of 50 nM alpha-[32P]ATP, suggesting a specific and separate Mg2+ binding site on the enzyme. Nitrate, sulfate, and thiocyanate at 100 mM or N-ethylmaleimide and 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole at 100 microM prevented the binding of the nucleotide to subunit II. The labeling of this subunit was effectively prevented by micromolar concentrations of three phosphonucleotides including those that cannot serve as substrate for the enzyme. It is concluded that a tightly bound ADP on subunit II is necessary for the activity of the enzyme.     

Internal anion binding site and membrane potential dominate the regulation of proton pumping by the chromaffin granule ATPase

Effects of anions and membrane potential on the reconstituted proton pump from chromaffin granules were investigated. When acetate was present inside of the vesicles, ATP-dependent proton uptake was absolutely dependent on external chloride. Without external chloride, however, substantial proton uptake was observed when chloride or sulfate was present inside of the vesicles. Inside negative membrane potential drove ATP-dependent proton uptake regardless of the anion species present inside or outside of the vesicles. It is concluded that the internal anion binding site and membrane potential regulate the proton pumping activity of the ATPase.     

Rhythmical jaw movements and lateral ponto-medullary reticular neurons in rats

Neuronal activity in the lateral reticular formation was investigated in urethane-anesthetized rats. Stimulation of anterior and posterior cortical areas induced two types of rhythmical jaw movements (RJM). The effects of stimulation of these cortical areas, the peripheral nerves, and the trigeminal motor nucleus on these neurons and their activity during the RJM were analyzed. The smallest percentage of neurons receiving anterior cortical input received peripheral input, and most neurons with posterior cortical input received peripheral input. Sixty per cent of reticular neurons showed the rhythmical firing closely related to the RJM. Therefore, these neurons may participate in masticatory pattern formation.     

Conformational change of bovine serum albumin by heat treatment

The thermal denaturation of bovine serum albumin (BSA) was studied at pH 2.8 and 7.0 in the range of 2–65°C. The relative proportions of -helix, -structure, and disordered structure in the protein conformation were determined as a function of temperature, by the curve-fitting method of circular dichroism spectra. With the rise of temperature at pH 7.0, the proportion of -helix decreased above 30°C and those of -structure and disordered structure increased in the same temperature range. The structural change was reversible in the temperature range below 45°C. However, the structural change was partially reversible upon cooling to room temperature subsequent to heating at 65°C. On the other hand, the structural change of BSA at pH 2.3 was completely reversible in the temperature range of 2–65°C, probably because the interactions between domains and between subdomains might disappear due to the acid expansion. The secondary structure of disulfide bridges-cleaved BSA remained unchanged during the heat treatment up to 65°C at pH 2.8 and 7.0.