Genetic differentiation of the indonesian crab-eating macaque (macaca fascicularis/it): I. Preliminary report on blood protein polymorphism

The blood protein polymorphism of five local populations of Indonesian crab-eating macaques (cynos) was examined by gel electrophoresis. The measured genetic variability was compared with previous research results for Asian macaques. It was found that the level of genetic variability was mostly lower than that of Asian mainland macaques but higher than that of local troops of Japanese macaques. A remarkable genetic differentiation in Bali cynos from South Sumatra/West Java cynos was demonstrated. This result was inconsistent with the subspecies classification of cynos in Indonesia.     

Enzymatic synthesis of silicon-containing dipeptides with 3-trimethylsilylalanine

In this study, the enzymatic synthesis of silicon-containing dipeptides with a silicon-containing amino acid, 3-trimethylsilylalanine (TMS-Ala), was attempted in ethyl acetate, and the effects of TMS-Ala on thermolysin-catalyzed dipeptide synthesis are also discussed. Benzyloxycarbonyl(Z)-TMS-Ala was recognized by thermolysin as a better substrate than Z-Leu, and various silicon-containing dipeptides, Z-(TMS-Ala)-Xaa-OMe (Xaa = Leu, Ile, Phe, etc.), could be obtained. The acceleration of the reaction rate in the synthesis of Z-(TMS-Ala)-Leu-OMe compared with Z-Leu-Leu-OMe synthesis was explained by the higher hydrophobicity of the side-chain of TMS-Ala containing a trimethylsilyl group. On the other hand, TMS-Ala-OMe was not accepted as the amino component because of the bulkiness of the trimethylsilyl group. The enantioselectivity of thermolysin was very high. Z-d-TMS-Ala was not a substrate, while Z-l-TMS-Ala served as a good substrate. Received: 5 October 1998 / Received last revision: 4 December 1998 / Accepted: 26 December 1998     

Tyrosine-specific dephosphorylation-phosphorylation with alkaline phosphatases and epidermal growth factor receptor kinase as evidenced by 31P NMR spectroscopy

The dephosphorylation of phospho-amino acids with alkaline phosphatase (AlPase) from calf intestine or Escherichia coli and the phosphorylation of bovine serum albumin (BSA) with epidermal growth factor (EGF) receptor kinase from human A431 epidermoid carcinoma cells were investigated by 31P NMR spectroscopy. The initial rates of the dephosphorylation of phospho-tyrosine (P-Tyr) and phosphoserine (P-Ser) with AlPase were essentially the same in the one-substrate system. In the two-substrate system (P-Tyr plus P-Ser), however, the ratio of the initial rate for P-Tyr vs. P-Ser was 2.4 to 4.5 depending on the buffer and pH conditions employed. This substantiates for the first time the specificity of AlPases to P-Tyr over P-Ser at the free amino acid level. In the stationary phase of the overall process, the dephosphorylation of P-Ser became slow compared to that of P-Tyr in the one-substrate system. The decrease in the rate for P-Ser was further pronounced in the two-substrate system. For this remarkable effect, the rephosphorylation of serine was responsible, as demonstrated in the reaction mixture containing serine, Pi, and AlPase. BSA phosphorylated by EGF receptor kinase exhibited sharp 31P resonances around 0 ppm at neutral pH, far distant from the peak positions (4.9 ppm) of histone H1 phosphorylated by cAMP-dependent protein kinase. These NMR data are directed evidence that BSA was phosphorylated exclusively at the tyrosyl residues, whereas the phosphorylation of histone H1 was at the seryl residues.     

Asymmetrical radical formation in D- and L-alanines irradiated with yttrium-90 beta-rays.

Radical formation in 90Y-beta-irradiated D- and L-alanines was studied using ESR. It was observed that the relative radical concentration by beta-irradiation was distinguishably (13.9-21.5%) more in D-alanine than in L-alanine. Discussion was made on the possible mechanisms for the observed results.     

Three-dimensional topology optimization model to simulate the external shapes of bone

Elucidation of the mechanism by which the shape of bones is formed is essential for understanding vertebrate development. Bones support the body of vertebrates by withstanding external loads, such as those imposed by gravity and muscle tension. Many studies have reported that bone formation varies in response to external loads. An increased external load induces bone synthesis, whereas a decreased external load induces bone resorption. This relationship led to the hypothesis that bone shape adapts to external load. In fact, by simulating this relationship through topology optimization, the internal trabecular structure of bones can be successfully reproduced, thereby facilitating the study of bone diseases. In contrast, there have been few attempts to simulate the external structure of bones, which determines vertebrate morphology. However, the external shape of bones may be reproduced through topology optimization because cells of the same type form both the internal and external structures of bones. Here, we constructed a three-dimensional topology optimization model to attempt the reproduction of the external shape of teleost vertebrae. In teleosts, the internal structure of the vertebral bodies is invariable, exhibiting an hourglass shape, whereas the lateral structure supporting the internal structure differs among species. Based on the anatomical observations, we applied different external loads to the hourglass-shaped part. The simulations produced a variety of three-dimensional structures, some of which exhibited several structural features similar to those of actual teleost vertebrae. In addition, by adjusting the geometric parameters, such as the width of the hourglass shape, we reproduced the variation in the teleost vertebrae shapes. These results suggest that a simulation using topology optimization can successfully reproduce the external shapes of teleost vertebrae. By applying our topology optimization model to various bones of vertebrates, we can understand how the external shape of bones adapts to external loads.     

Inappropriate antidiuretic hormone syndrome in craniofacial surgery

Three instances of inappropriate ADH syndrome following craniofacial operations are reported. The cornerstone to diagnosis is careful fluid and electrolyte monitoring. Treatment consists of fluid restrictions in the acute phase and demeclocycline for refractory cases. Seizures should be symptomatically treated. Surgeons involved in the care of craniofacial anomalies must be aware of this syndrome because the symptoms closely mimic those commonly observed following intracranial procedures. If unrecognized, the consequence is potentially lethal.     

Paternity discrimination and inter-group relationships of chimpanzees at Bossou

A small group of wild chimpanzees at Bossou, southeastern Guinea, is semi-isolated, occupying a home-range which is several kilometers from those of other groups. The group has had only one adult male since 1985, raising the probability of inbreeding. Direct observation suggests that this male was the father of all infants born in the group since 1985. In 1991 individually identified samples of food wadges, hair, and feces were collected from most of the group members. These samples were analyzed using GT dinucleotide repeat polymorphisms to determine familial relationships. The genetic analysis revealed that the resident adult male was the probable father of only three out of the four infants analyzed. It is suspected that an adult male from a neighboring group was the father of the fourth infant, born in late 1986 or early 1987.