Embryos at 4 cell stage obtained from Sarda ewes superovulated with FSHp (Sigma) were micromanipulated in order to obtain single blastomeres (1/4 E). The 1/4 E have been located randomly in two ...groups. In the first (Group A n. 30) the 1/4 E have been put back in empty zonae pellucidae; in the second (Group B n. 21) they have been microencapsulated in sodium alginate (1.1%) by dropping cell-alginate solution in a 1.5% CaCl2. Each capsule (1 mm diameter) contained four 1/4 E. The blastomeres have been co-cultured for 5 days in CZB medium on oviductal cell monolayer in a humidified incubator (5% CO2, 95% air, 38.5 degrees C). No differences were found between the groups reaching blastocyst stage after the end of the culture period (A 50%-B 47%).
We report the results of a prospective study conducted in Italy to evaluate the efficacy, safety, predictability, and complications of excimer laser photorefractive keratectomy for the correction of ...myopia. METHODS. Photorefractive keratectomy was performed on 1236 myopic sighted eyes in 16 centers, using the Summit Excimed 193 nm excimer laser. The attempted correction ranged from -0.80 to -25.00 diopters (mean, -7.83 +/- 3.88 D). The population was divided into three groups of attempted correction: between -0.80 and -6.00 D, between -6.10 and -9.90 D, and between -10.00 and -25.00 D. We report the data of 1165 eyes at 1 month, 970 eyes at 3 months, 752 at 6 months, and 330 at 12 months. At each visit, we evaluated (1) the refractive changes over time; (2) the difference between attempted and achieved correction; (3) uncorrected and best spectacle corrected visual acuity; and (4) haze.
Twelve months after surgery, the spherical equivalent refractive error in 146 eyes with attempted correction of -0.80 to -6.00 D was -0.52 +/- 1.04 D; 104 eyes (71.2%) were within +/- 1.00 D of attempted correction. In 145 eyes with attempted correction of -6.10 to -9.90 D, the spherical equivalent refractive error was -1.66 +/- 1.88 D; 50 eyes (34.5%) were within +/- 1.00 D of attempted correction. The spherical equivalent refractive error in 39 eyes with attempted correction of -10.00 to -25.00 D was -1.86 +/- 3.47 D; 11 eyes (28.2%) were within +/- 1.00 D of attempted correction. Eight eyes (2.4%) lost two or more Snellen lines of best spectacle corrected visual acuity. None of the treatments caused severe postoperative complications, or scarring.
Photorefractive keratectomy proved safe and effective, but highly predictable only in the correction of myopia up to -6.00 D.
Four cell embryos collected by laparatomy from Sardinian breed ewes superovulated with FSH-p (16 mg Sigma), were divested of their zonae pellucidae (ZP) by micromanipulation or chemical methods ...(pronase 0.5%, tyrode pH 2.2). The blastomeres were separated by pipetting using a flame polished pasteur pipette in a Ca free medium (PBS. Sigma) and were inserted into previously evacuated Z.P. using a Leitz micromanipulator. The Z.P. were removed either mechanically or with acid tyrode; pronase was unable to digest them after incubation at 30 degrees C for 120 minutes. The single blastomeres were cocultured on a monolayer of ovine oviductal epithelial cells in TCM 199 + 10 FCS at 38 degrees C in 5% CO2 for 60 hours. No developments were observed in blastomeres obtained by acid digestion of the ZP while 50% of the other blastomeres continued their development until the 16 cell stages. Our results suggest that coculture with oviductal epithelial cell monolayers can support in vitro development of single ovine blastomeres.
This article describes the migratory patterns resulting from differential incidence of lethal infections in traditional Eurasian civilizations. Further, it examines how changes in modern ...communication and public health management have interrupted the traditional patterns of population circulation. The communication of infection influenced the standard mass migration patterns for traditional Eurasian civilization. The rural flow to urban centers and migration to the periphery replaced and replenished populations thinned by infections. This pattern was the standard underpinning of traditional civilization in the temperate zone of Eurasia from 2000 B.C. to A.D. 1750. A second, less massive movement of "elites" also occurred. Barbarian elites moved against the city, and urban elites-trades, missionaries, refugees-moved to the periphery. While numerically small, this pattern was often of key importance in diffusing ideas, techniques, and specialized skills. The period of Eurasian discovery in the 16th century disturbed the traditional migration patterns and led to homogenization of disease pools by almost 1750. The first effect of the new disease regimen was an unparalleled acceleration of the patterns of migration towards the frontier, while the second was an initial intensification of urban epidemics in the civilized communities of the Old World. The establishment of preliminary public-health measures and dramatic technological advances began to have an effect by the end of the 19th century. Consequently, the older patterns of in-migration began to meet new resistance, as urban populations became able to sustain themselves biologically and even increase their numbers. Simultaneously, frontier zones suitable for settlement disappeared, with most areas brought within the circle of civilized communities by 1900. This has led to a population explosion and the development of megalopolis. This extraordinary alteration of long-standing epidemiological and migratory regimens has massive consequences for the future.
Genetic markers would be useful to study the transmission of type 2 diabetes and to identify patients with enhanced risk of development of late diabetic complications. The aim of this study was to ...evaluate the influence of selected possible genetic markers on the development of diabetic complications. One hundred and eighty patients with type 2 diabetes (79 males, 101 females) were therefore studied with respect to ABO and Rh blood grouping and chlorpropamide alcohol flush (CPAF) and acetylator phenotype status, in addition to life style (smoking, dietary, alcohol and drug taking habits) and metabolic indexes (HbA1, M-value, serum cholesterol, serum triglycerides), with regard to late complications coronary heart disease (CHD), arterial hypertension (AH), peripheral vascular disorders (PVD), retinopathy and nephropathy. None of the genetic markers considered appeared to be associated with diabetic complications. Multiple logistic analysis identified different risk-factors for each complication: AH and age for CHD; hyperlipidaemia for AH; age of patients for PVD; duration of diabetes for retinopathy; AH for nephropathy. It is concluded that the possible genetic markers evaluated in this study do not identify a higher or lower risk for late complications. On the contrary, most of the risk factors identified support previous studies. Active correction of these risk-factors might improve the overall prognosis of patients with type 2 diabetes.
Assuming that aboriginal behavior was recorded on chipped-stone implements and debitage, and assuming that the analyst can train himself to recognize and interpret that record, then a classification ...of lithic artifacts based on manufacturing behavior may be considered an inherent classification. Lithic behavioral classification is examined from the perspective of other archaeological classifications as well as from general taxonomic theory. Advantages of behavioral analysis in the examination of change, adaptation, process, systems theory, and the nature of artifact variability are explored. The artifacts of a core-blade reduction strategy excavated from Chalchuapa, El Salvador, a major Maya Highland site, are described to exemplify behavioral classification.
This paper is a review of the fossil evidence bearing upon the problem of the origin and evolution of Homo sapiens and his relationship to Neanderthal Man, with special attention to the finds from ...Central and Eastern Europe, less well-known to the international community than those of Western Europe and elsewhere. Emphasis is placed on new discoveries supplementing the existing network of finds and on the reinterpretation of earlier finds through recent studies. The importance of finds of the remains of several individuals at a single site, which offer valuable insight into the morphological variability of the prehistoric population, is stressed. On the basis of this survey of the evidence, the following conclusions (among others) are drawn: (1) The Neanderthal finds from Central and Eastern Europe display pronounced morphological variability, even within a single site, and this variability is associated with wide variation in cultural inventory. These finds show, to various degrees and in various frequencies, many of the characteristics that we find fully developed and universal in H. sapiens sapiens. Chronologically, they extend into the W 1/2 interstadial, the period to which the oldest finds in this region of Upper Paleolithic Man of the modern type also belong. (2) The Upper Paleolithic fossil man finds and, also, less markedly, those of the Neolithic, include individuals of the so-called primitive sapient type, displaying archaic morphological characteristics, again to various degrees and in various frequencies. Associated with this physical variation is, again, wide variation in culture. (3) The evidence thus seems to demand that we classify Neanderthal Man as H. sapiens neanderthalensis and Upper Paleolithic Man as H. sapiens sapiens.
