[Morphological studies of hydroxyapatite crystals exposed to disodium pamidronate]. / Estudios morfológicos de los cristales de hidroxiapatita tratados con pamidronato disódico.

"In vitro" effects of disodium pamidronate on hydroxyapatite crystals morphology, and some "in vivo" data from bone powder of tibia and vertebrae from treated young and mature rabbits are here reported. Hydroxyapatite, synthesized following Rigoli et al method, and bone powder from rabbits were studied with X-ray, infrared and raman emission techniques for crystallographic analysis. Adsorption studies were also performed with a balanced solution of hydroxyapatite exposed to different times, 48, 120 and 168 hours and concentrations 1 x 10(-5) M, 3 x 10(-5) M, 8 x 10(-5) M y 1 x 10(-4) M of pamidronate. Infrared and raman spectrometry were not conclusive due to technical bias, but X-ray difractograms showed pure hydroxyapatite crystals in an hexagonal system. At constant time, pamidronate concentrations were varied, showing after 48 hours of exposition, a slight growth in the 002 plane, an aleatoric behavior in 213 and a marked increase in 004. After 120 hours, 002 plane is steady with a net growth in 004 and 213. After 168 hours, the 3 mentioned planes grow in proportion to pamidronate concentrations, tending to enlarge the crystal shape. Plane 13 markedly grow with pamidronate 8 x 10(-5) M a 1 x 10(-4) M, which are biologically high concentrations. Potentiometric assessments, in the 1 x 10(-5) to 1 x 10(-4) M range of concentrations show that bisphosphonate was completely adsorbed to the crystals. Additional "in vivo" observations showed changes in bone powder crystals isolated from pamidronate treated young animals, involving a growing of planes 002 and 211, in samples from both epiphysis and diaphysis, regarding untreated samples. Changes were more evident at epiphysis. In mature rabbits, it was shown a decrease in basal plane 002 and growing at 210, 211 and 310 with a trend to enlarge the crystal shape in diaphysis and to shorten it in vertebrate spongiosa. The "in vivo" doses are equivalent to those used by Ferretti et al. in intact rats with pamidronate low dose groups, showing an improvement of bone material properties and stiffness. Thus, it may rather be lower than the "in vitro" used concentrations. In concordance with above experimental conditions it can be concluded that bisphosphonates exert morphological changes in hydroxyapatite crystals, in a dose dependent manner, at least when high concentrations are used. In addition, it is postulated that changes observed on "in vivo" samples may be the result with other adaptative factors as for example the local mechanical usage. The latter data were limited, and should be studied with more details if an extrapolation to the bisphosphonate treated osteoporotic women is intended. Finally, it is suggested that any agent that changes BMU activity (all known anti-osteoporotic drugs) may potentially modify the quality of hydroxyapatite crystals, affecting in turn the bone resistance to fracture, independently from the quantity of bone mass gained. Thus, to help predicting the consequences on skeletal fragility, there is a need to know the direct or indirect effect of drugs on bone crystals.

[Triatoma infestation in the San Luis del Palmar Department of Corrientes Province, Argentina]. / Triatomismo del Departamento San Luis del Palmar de la provincia de Corrientes, Argentina.

The purpose of this study was to determine domestic and peridomestic infestation of Triatominae, Trypanosoma cruzi infection rates, and the prevalence of human seroreactivity in rural areas of the Department of San Luis del Palmar, Corrientes, Argentina (Fig. 1). The study took place from April 1986 to May 1989. The Department of San Luis del Palmar covers an area of 2551 km2 and is part of the Neotropical biogeographic region, Chacoan Dominion and Province. The climate is of the subhumid type. The mean annual temperature is 21.6 degrees C. Some localities were chosen because of the presence of triatominae. Households were carefully examined and classified according to their building materials. A 0.2% solution of tetrametrine was sprayed in all possible hiding places to dislodge bugs, which were collected by capture/hour/man methods. A survey to determine the socioeconomical, sanitary, and cultural conditions of house-dwellers was carried out. The same method was used to examine peridomiciles and total demolition was carried out in the positive ones. Fecal examination was carried out to verify the presence of T. cruzi in collected insects and observed at 400X. Human blood was obtained through venipuncture. The serum was kept in a freezer until examined. Serologic studies included indirect hemagglutination test (IHAT) and indirect immunofluorescence antibody test (IFAT). Positive titer for IHAT and IFAT was 1/64. Seroreactives were those that had two positive assays. The whole data obtained was analyzed by chi 2 tests. From one hundred households studied, 80% belonged to huts and 20% to houses. Mud walls were predominant in huts while brick walls were predominant in houses.(ABSTRACT TRUNCATED AT 250 WORDS)

Triatomismo del Departamento San Luis del Palmar de la provincia de Corrientes, Argentina. / [Triatoma infestation in the San Luis del Palmar Department of Corrientes Province, Argentina]

The purpose of this study was to determine domestic and peridomestic infestation of Triatominae, Trypanosoma cruzi infection rates, and the prevalence of human seroreactivity in rural areas of the Department of San Luis del Palmar, Corrientes, Argentina (Fig. 1). The study took place from April 1986 to May 1989. The Department of San Luis del Palmar covers an area of 2551 km2 and is part of the Neotropical biogeographic region, Chacoan Dominion and Province. The climate is of the subhumid type. The mean annual temperature is 21.6 degrees C. Some localities were chosen because of the presence of triatominae. Households were carefully examined and classified according to their building materials. A 0.2

solution of tetrametrine was sprayed in all possible hiding places to dislodge bugs, which were collected by capture/hour/man methods. A survey to determine the socioeconomical, sanitary, and cultural conditions of house-dwellers was carried out. The same method was used to examine peridomiciles and total demolition was carried out in the positive ones. Fecal examination was carried out to verify the presence of T. cruzi in collected insects and observed at 400X. Human blood was obtained through venipuncture. The serum was kept in a freezer until examined. Serologic studies included indirect hemagglutination test (IHAT) and indirect immunofluorescence antibody test (IFAT). Positive titer for IHAT and IFAT was 1/64. Seroreactives were those that had two positive assays. The whole data obtained was analyzed by chi 2 tests. From one hundred households studied, 80

belonged to huts and 20

to houses. Mud walls were predominant in huts while brick walls were predominant in houses.(ABSTRACT TRUNCATED AT 250 WORDS)

Triatomismo del Departamento San Luis del Palmar de la provincia de Corrientes, Argentina. / [Triatoma infestation in the San Luis del Palmar Department of Corrientes Province, Argentina]

The purpose of this study was to determine domestic and peridomestic infestation of Triatominae, Trypanosoma cruzi infection rates, and the prevalence of human seroreactivity in rural areas of the Department of San Luis del Palmar, Corrientes, Argentina (Fig. 1). The study took place from April 1986 to May 1989. The Department of San Luis del Palmar covers an area of 2551 km2 and is part of the Neotropical biogeographic region, Chacoan Dominion and Province. The climate is of the subhumid type. The mean annual temperature is 21.6 degrees C. Some localities were chosen because of the presence of triatominae. Households were carefully examined and classified according to their building materials. A 0.2

solution of tetrametrine was sprayed in all possible hiding places to dislodge bugs, which were collected by capture/hour/man methods. A survey to determine the socioeconomical, sanitary, and cultural conditions of house-dwellers was carried out. The same method was used to examine peridomiciles and total demolition was carried out in the positive ones. Fecal examination was carried out to verify the presence of T. cruzi in collected insects and observed at 400X. Human blood was obtained through venipuncture. The serum was kept in a freezer until examined. Serologic studies included indirect hemagglutination test (IHAT) and indirect immunofluorescence antibody test (IFAT). Positive titer for IHAT and IFAT was 1/64. Seroreactives were those that had two positive assays. The whole data obtained was analyzed by chi 2 tests. From one hundred households studied, 80

belonged to huts and 20

to houses. Mud walls were predominant in huts while brick walls were predominant in houses.(ABSTRACT TRUNCATED AT 250 WORDS)

Independent conformational changes caused by calmodulin and calcium in the cardiac microsomal (Ca2+, Mg2+)-ATPase during its ATP hydrolysis-ATP synthesis cycle.

The cardiac sarcoplasmic reticulum preparation employed in this study presented two fractions of associated calmodulin, one easily removable and the other tightly bound. The latter one was resistant to treatment with EGTA and high ionic strength. The forward or hydrolytic component of the (Ca2+, Mg2+)-ATPase cycle of calmodulin-free vesicles was stimulated when preincubated with trypsin, as opposed to the inhibition of this activity when the intact or calmodulin containing vesicles were employed in parallel assays. Interestingly, the reverse reaction of the ATPase cycle or ATP in equilibrium Pi exchange reaction found in both types of vesicles, was more sensitive to exposure to trypsin. Although a drastic inhibition of this exchange reaction was observed independent of the presence of the modulator, this reaction was transiently stimulated when the calmodulin-free vesicles were preincubated with a low trypsin to protein ratio. The differential effect of trypsin upon each reaction indicates that the equilibrium between the E1 and the E2 states of the enzyme is displaced. [125I]calmodulin was found to bind equally to the Ca X E1 approximately P and the E2 - P intermediates of the isolated enzyme formed with the ATP and Pi respectively. It is suggested the formation of an independent overall conformational state for the (Ca2+, Mg2+)-ATPase in the presence of calmodulin.