Functional Restoration of a Midforearm Level Amputation using the Second Toe Transfer.

Unilateral midforearm level amputation is a severely debilitating situation. The present solution for this problem is either restoration of function using a prosthetic hand, or a vascularized composite allotransplant (VCA) in some very selected cases. In cases of distal forearm level amputations, even vascularized second toe transfer could be done on the radial side of the hand to achieve good functional restoration. We present a case of midforearm level amputation in which the second toe transfer has been done above the level of insertion of pronator teres muscle to achieve meaningful function. This report highlights the fact that a single toe transfer could be helpful in achieving meaningful prehension, even at this proximal.

Aedes aegypti: origin of a "new" chromosome from a double translocation heterozygote.

An apparent enhancement of crossing-over occurs in the region common to two translocated chromosomes derived from two different reciprocal translocations in the yellow-fever mnosquito, Aedes aegypti. A "new" chromosome containing parts of all three linkage groups is created through crossing-over. In a reversible process, two haploid translocated sets in the double translocation heterozygote produce a new, normal chromosome. set and vice versa in alternating generatiots.

Frequencies of mitochondrial DNA haplotypes in laboratory cage populations of the mosquito, Aedes albopictus.

A laboratory cage experiment was undertaken to study changes over time in the frequencies of two mitochondrial DNA (mtDNA) haplotypes in the mosquito, Aedes albopictus, under two conditions: bidirectionally compatible matings and unidirectionally incompatible matings. Frequencies were monitored for 10 generations in three replicate cages for each of the two conditions above. In cages with bidirectionally compatible strains, changes in haplotype frequencies were nondirectional and neither haplotype increased in frequency. Statistical analysis of relative proportions of the two haplotypes in each generation indicated that the magnitude of the observed fluctuations could be expected under an assumption of random genetic drift alone. In cages with unidirectionally incompatible matings, mtDNA of females that lay inviable eggs upon mating with males of another strain, decreased significantly in the F1 generation and was completely replaced in the F2 generation.

Patterns of variation in the rDNA cistron within and among world populations of a mosquito, Aedes albopictus (Skuse).

A restriction map was constructed of the ribosomal cistron in a mosquito, Aedes albopictus (Skuse). The 18s, 28s and nontranscribed spacer (NTS) regions were subcloned and used to probe for intraspecific variation. Seventeen populations were examined throughout the world range of the species. No variation was detected in the coding regions but extensive and continuous variation existed in the NTS. The NTS consisted of two nonhomologous regions. The first region contained multiple 190-bp AluI repeats nested within larger XhoI repeats of various sizes. There was a large number of length variants in the AluI repeat region of the NTS. No repeats were found in the second region and it gave rise to relatively fewer variants. An analysis of NTS diversity in individual mosquitoes indicated that most of the diversity arose at the population level. Discriminant analysis was performed on spacer types in individual mosquitoes and demonstrated that individuals within a population carried a unique set of spacers. In contrast with studies of the NTS in Drosophila populations, there seems to be little conservation of spacers in a population. The importance of molecular drive relative to drift and selection in the generation of local population differentiation is discussed.

Preparation and characterization of (125)i labeled bovine serum albumin.

Bovine serum albumin is a model protein, which has been conventionally used as protein standard and in many areas of biochemistry, pharmacology and medicine. Radioiodination procedure for bovine serum albumin employing chloramine-T as an oxidant with slight modification was evaluated critically to establish the optimal conditions for the preparation of radiolabeled tracer ((125)I-BSA) with required specific activity without impairing the immune reactivity and biological activity. Optimized radioiodination procedure involving 10 µg of chloramine-T along with 20 µg of sodium metabisulphite with 60 seconds incubation at 2° yielded (125)I-BSA with high integrity.

Random amplified polymorphic DNA of mosquito species and populations (Diptera: Culicidae): techniques, statistical analysis, and applications.

A polymerase chain reaction (PCR)-based method is described for the identification and differentiation of mosquito species and populations. The method, described first by Williams et al. (1990), employs single 10 base-long primers of arbitrary DNA sequence and results in the amplification of random segments of DNA known as random amplified polymorphic DNA (RAPD). We wished to determine if RAPD of mosquito DNA could be used for the differentiation of species and populations, identification of unknown specimens, and the reconstruction of phylogeny. RAPD of mosquito DNA results in the amplification of a series of DNA fragments of varying length. Most amplified fragments are unique to an individual; however, our data indicated that in each of the five species of Aedes examined, some fragments are species-specific and are present in all individuals of that species. This enabled us to derive a diagnostic profile for each of the five species. A nearest-neighbor analysis of all the amplified DNA fragments discriminated among species on a multivariate basis. Several individuals of Aedes albopictus (Skuse), included in the analysis as "unknowns," were correctly identified as belonging to Ae. albopictus. UPGMA clustering of presence-absence data enabled the separation of different Aedes species as well as different populations of Ae. albopictus. The entomological applications of RAPD include the construction of diagnostic profiles for species identification and differentiation among conspecific populations.

Midgut basal lamina thickness and dengue-1 virus dissemination rates in laboratory strains of Aedes albopictus (Diptera: Culicidae).

Strain differences in midgut basal lamina thickness, assessed by measurement in transmission electron micrographs, and disseminated infection rates of dengue-1 virus were compared among three laboratory strains of Aedes albopictus (Skuse). Mean basal lamina thickness for the New Orleans and Houston strains were significantly greater than those for the Oahu strain, which exhibits a higher disseminated infection rate than the former two. Although basal lamina thickness among the F1 progeny of reciprocal crosses of the Oahu and Houston strains were intermediate between the parental strains, they were too variable to be useful as markers in genetic studies. Measurements of basal laminae among individuals of the New Orleans strain, with disseminated or nondisseminated infections, failed to demonstrate a role for basal lamina thickness as a modulator of dengue-1 virus dissemination across the midgut epithelium of Ae. albopictus.

Laboratory study of competition between United States strains of Aedes albopictus and Aedes aegypti (Diptera: Culicidae).

Mosquito abatement workers in Houston, Tex., and New Orleans, La., have observed that the recent introduction of Aedes albopictus (Skuse) has been accompanied by a decline and virtual disappearance of Ae. aegypti (L.). This suggests competitive displacement but contradicts the direction of displacement observed in native habitats of Ae. albopictus. The paper reports a series of laboratory studies on competition between U.S. strains of the two species. Larval survivorship, size, and development time were monitored in increasing densities of pure and mixed cultures of the two species under limited and optimal diets. Oviposition preferences were examined by offering gravid females cups containing first or fourth instars of either species. Ethological isolation was studied by simultaneously offering virgin females of one species to males of both species and monitoring courtship behavior as well as rates of oviposition, percentage of hatch, and embryonation. The results of the larval competition studies suggest that interspecific competition increased development time only slightly and had no effect on survival of Ae. albopictus. Competition increased survival in Ae. aegypti. Size of both species was influenced by interspecific competition, but the magnitude and direction of the effect was inconsistent between strains and diets such that neither species emerged consistently larger. The results of the oviposition study indicated a higher fecundity in Ae. aegypti but otherwise demonstrated that both species oviposit without regard to the presence, age, or species of larvae in the oviposition container. The ethological isolation tests demonstrated that Ae. aegypti males were more sexually aggressive than males or Ae. albopictus. However, Ae. albopitus females placed with increasing densities of Ae. aegypti males demonstrated no decrease in rates of oviposition, and eggs laid showed equal rates of hatch and embryonation. In general, the results do not suggest that the U.S Ae. albopictus population is inherently more competitive in the laboratory than Ae. aegypti. Other reasons for the observed decline in Ae. aegypti in the United States are discussed.

Variation in the efficiency of vertical transmission of dengue-1 virus by strains of Aedes albopictus (Diptera: Culicidae).

Five geographical strains of Aedes albopictus (Skuse) were compared for their ability to transmit vertically a dengue-1 isolate from Jamaica. The OAHU strain of Ae. albopictus and a strain of Aedes aegypti (L.) from the United States were included as controls. The offspring of orally infected females were assayed individually for vertical infection. Vertical transmission rates among strains ranged from 11 to 41%, and filial infection rates of strains ranged from 0.5 to 2.9%. Filial infection rates of individual positive families within strains ranged from 1.4 to 17.4%. These rates were higher than those previously recorded for Ae. albopictus. The observed differences in rates of vertical transmission among the strains were not statistically significant, because 95% of the measured variation was attributed to families within strains. The most significant source of variation in vertical transmission of dengue-1 by Ae. albopictus was at the individual level.

Clitoria ternatea root extract enhances acetylcholine content in rat hippocampus.

Treatment with 100 mg/kg of Clitoria ternatea aqueous root extract (CTR), for 30 days in neonatal and young adult age groups of rat, significantly increased acetylcholine (ACh) content in their hippocampi as compared to age matched controls. Increase in ACh content in their hippocampus may be the neurochemical basis for their improved learning and memory.

Genetics of Aedes albopictus.

Aedes albopictus is an important vector of dengue fever and dengue hemorrhagic fever in Southeast Asia. Its distribution extends from Madagascar to Hawaii and is currently expanding. From its proposed origin in Southeast Asia, Ae. albopictus has migrated as far as Mauritius and Madagascar to the west and Korea, Japan, Guam, Hawaii and other Pacific Islands to the east. In the continental United States, it was originally reported in the Texas area in August 1985 and is now well established in several states. This paper reviews information on distribution, cytology and genetics of Aedes albopictus. In addition, it includes comments on its competitive interaction with several other species. Relevant information on evolutionary genetics of certain other related sibling species is also included for comparative purposes.

Variation in the vector competence of geographic strains of Aedes albopictus for dengue 1 virus.

Eight geographic strains of Aedes albopictus from Asia and North America and one North American strain of Aedes aegypti were tested for their vector competence with dengue 1 virus. Three groups of Ae. albopictus were established based on their vector competence: a) the OAHU laboratory strain, b) the three Malaysian strains, and c) the TOKYO and three North American strains. The three North American strains were similar to the strain of Ae. aegypti from Houston, Texas in their ability to transmit dengue 1 virus. A comparison of barriers to infection and transmission suggests that Ae. albopictus HOUSTON represents an introduced strain distinct from the more similar MEMPHIS and NEW ORLEANS strains. Based on these studies the North American strains were seen as more similar to a northern Asian strain (TOKYO) than to the three Malaysian (southern Asia) strains, supporting the current hypothesis that the indigenous strains of Ae. albopictus recently introduced into the United States had a northern Asian origin.

Clitoria ternatea (Linn) root extract treatment during growth spurt period enhances learning and memory in rats.

Neonatal rat pups (7 days old) were intubated with either 50 mg/kg body weight or 100 mg/kg body weight of aqueous root extract of Clitoria ternatea (CTR) for 30 days. These rats were then subjected to open field, two compartment passive avoidance and spatial learning (T-Maze) tests (i) immediately after the treatment and (ii) 30 days after the treatment, along with age matched normal and saline control rats. Results showed no change in open field behaviour, but showed improved retention and spatial learning performance at both time points of behavioural tests, indicating the memory enhancing property of CTR which implicates a permanent change in the brain of CTR treated rats.

White-eye, a new mutant in Aedes scutellaris katherinensis.

White-eye (w), a new mutant in Aedes scutellaris katherinensis Woodhill, of the Aedes (Stegomyia) scutellaris subgroup is described. It is controlled by a single autosomal recessive gene, and is detectable at all developmental stages. Penetrance is complete and its viability and expressivity are good. It is an excellent genetic marker.