Purification and characterization of the CheZ protein of bacterial chemotaxis.

The cheZ gene is the most distal of five genes that comprise the Meche operon of the Salmonella typhimurium chemotaxis system. We have determined the sequence of the cheZ gene along with an 800-nucleotide flanking region at its 3' end. The flanking sequence contains an open reading frame that probably corresponds to the 5' end of flaM.

S-adenosylmethionine may not be essential for signal transduction during bacterial chemotaxis.

We previously showed that a mutant strain of Salmonella typhimurium completely deficient in both the chemoreceptor methylating (CheR) and demethylating (CheB) enzymes can still exhibit chemotaxis to aspartate and other attractants (J. Stock, A. Borczuk, F.

Purification and characterization of the S-adenosylmethionine:glutamyl methyltransferase that modifies membrane chemoreceptor proteins in bacteria.

The enzyme (EC 2.1.1.

A second type of protein methylation reaction in bacterial chemotaxis.

CheZ is the product of one of six genes required for sensory processing in Escherichia coli and Salmonella typhimurium chemotaxis. This 24-kDa cytoplasmic protein is modified by a posttranslational methylation reaction. The modified residue has been identified by analysis of radioactively labeled protein from two-dimensional electrophoretograms and Edman degradation of CheZ protein isolated by immunoaffinity chromatography using anti-CheZ monoclonal antibodies.

Semiochemicals produced by western balsam bark beetle,Dryocoetes confusus Swaine (Coleoptera: Scolytidae).

The most prominent beetle-produced volatiles identified in the abdominal extracts of maleDryocoetes confusus Swaine after they had bored for 24 hr in logs of subalpine fir,Abies lasiocarpa (Hook.) Nutt. were:exo andendo-brevicomin,trans-verbenol, verbenone, myrtenol,trans-pinocarveol,cis- andtrans-p-menthen-7-ol, 3-caren-10-ol, and several monoterpenes and sesquiterpenes.

Allogeneic bone marrow transplantation for acute lymphoblastic leukemia during first complete remission.

Patients with acute lymphoblastic leukemia who have poor prognostic features at diagnosis usually have a short disease-free survival in spite of successful remission induction. Those poor risk features are: age over 30 years, a white blood cell count over 25,000/microliter, certain translocations of chromosomes, and requirement for more than six weeks of induction chemotherapy to attain a complete remission. We have used high-dose radiochemotherapy to prepare 39 patients with acute lymphoblastic leukemia in first complete remission (1 infant and 38 adults; median age 23 years) for bone marrow transplantation from histocompatible sibling donors.

Use of DNA restriction fragment length polymorphisms to document marrow engraftment and mixed hematopoietic chimerism following bone marrow transplantation.

We have studied the feasibility of using DNA restriction fragment-length polymorphisms (RFLP) to study marrow engraftment in 27 patients after allogeneic bone marrow transplantation, and have compared these results with those obtained using red blood cell antigens, cytogenetics, and immunoglobulin allotypes. Using highly polymorphic DNA probes, we have documented stable chronic mixed hematopoietic chimerism, have identified transient mixed chimeras, have excluded mixed chimerism with high probability in retrospective studies even when a pretransplant DNA sample was not available, have documented marrow engraftment in the early posttransplant period, and have studied the origin of leukemic cells in patients with recurrent disease. We have evaluated the advantages and disadvantages of several genetic markers and have developed tentative statements concerning the prognosis of patients with mixed chimerism.

Identification of a possible nucleotide binding site in CheW, a protein required for sensory transduction in bacterial chemotaxis.

CheW is an essential component of the system which mediates chemotaxis in Salmonella typhimurium and Escherichia coli. Here we report the nucleotide sequence of the cheW gene as well as the purification and characterization of the CheW protein. The DNA sequence predicts a protein of 18,000 molecular weight.

Homologies between the Salmonella typhimurium CheY protein and proteins involved in the regulation of chemotaxis, membrane protein synthesis, and sporulation.

Chemotactic receptors at the bacterial cell surface communicate with flagellar basal structures to elicit appropriate motor behavior in response to extracellular stimuli. Genetic and physiological studies indicate that the product of the cheY gene interacts directly with components of the flagellar motor to control swimming behavior. We have purified and characterized the Salmonella typhimurium CheY protein and have determined the nucleotide sequence of the cheY gene.

Effect of cholesterol oxidation products on cholesterol metabolism in the laying hen.

Two experiments were conducted to determine the effect of purified cholesterol and oxidized cholesterol in the diet of the laying hen on egg production characteristics, in vitro - in ovo utilization of acetate for cholesterol biosynthesis, and the activity of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme in biosynthesis of cholesterol. Previous work has demonstrated inhibition of cholesterol synthesis by cholesterol oxides in tissue culture cells but not in hepatic tissues of animals through dietary administration. Feeding .

[The rat as a training model for microvascular surgery. Methods and results].

Before the clinical application of microvascular surgery the experimental training is necessary. The techniques of end-to-end anastomosis of femoral artery and vein and groin flap autotransplantation are described in detail on the rat model and results are presented. These techniques seems to be suitable for persons still learning without much experience.

The origin of mitotic sex-chromosome association in the brush-tailed possum, Trichosurus vulpecula (marsupalia:phalangeridae).

Nonrandom associations between the sex chromosomes of the brush-tailed possum, Trichosurus vulpecula, were found to be due to association of nucleolar organizer regions (NOR's) on the X and Y chromosomes. NOR association was also observed between an autosome and the X chromosome. These findings, based on silver staining, are in contrast to the report of MURRAY (1977), who observed sex-chromosome association in this animal and indicated that these nonrandom associations may reflect an association between heterochromatic regions during interphase.

Chromosomal variation and constitutive heterochromatin in three porpoise species (genus Stenella).

Chromosomes from cultured fibroblasts of two Pacific porpoise species, Stenella attenuata and S. longirostris, and one Atlantic species, S. dubia, were compared to test the feasibility of using variation in constitutive heterochromatin and other chromosomal characteristics for analyses of population relationships and defining stocks of endangered porpoises.

Anatomy of the superficial temporal artery.

The anatomy of the superficial temporal artery was investigated in radiographic and cadaveric studies. The superficial temporal artery divides into an anterior and posterior branch, and the diameters of these vessels are similar. The anatomy of these two vessels is described, and implications for their use in reconstructive flaps are suggested.

Assessment of urinary tract obstruction using a perfusion technique.

A perfusion technique is described which enables differentiation in a dilated upper urinary tract between one which is obstructed and one which is not. It has been found invaluable in the assessment of patients prior to surgical intervention and has saved many patients from an operation.

Chromosome banding patterns and the nucleolar organizer region of the eastern mole (Scalopus aquaticus).

The C and G chromosome banding patterns and the AgAS positive sites (NOR regions) of cultured lung cells of the Eastern mole (Scalopus aquaticus) are presented. A distinctive secondary constriction is found on a pair of autosomes instead of on the X-chromosome as previously believed. The presence of a heterochromatic heteromorphism is noted and a large amount of constitutive heterochromatin is present in the karyotype.