Biomedical subjects

G Kowalchuk

Publications and source records attributed to G Kowalchuk.

4 recordsLinked to original sources

PubMed1994

Unusual G + C content and codon usage in catIJF, a segment of the ben-cat supra-operonic cluster in the Acinetobacter calcoaceticus chromosome.

The nucleotide (nt) sequence of a 5.3-kb DNA segment containing the Gram- Acinetobacter calcoaceticus catBCIJFD operon is reported. This information completes determination of a 16-kb nt sequence containing the twelve ben and cat structural genes encoding enzymes required for catabolism of benzoate via the beta-ketoadipate pathway. Many of these genes can be traced to a common ancestry with genes from other organisms containing DNA with widely divergent G + C content. The A. calcoaceticus ben and cat genes are arranged in a supra-operonic cluster containing one known regulatory gene and three additional open reading frames (ORFs) that may have regulatory functions. Thirteen of the ben and cat genes, including the three ORFs with unknown function, are typical for A. calcoaceticus in that they possess a G + C content of 44.9 +/- 2.5%. Three exceptional A. calcoaceticus genes (catI, catJ and catF) possess G + C contents of 56.5 +/- 1.3%. These differences in G + C content are reflected in the distinctive patterns of codon usage shared by catI, catJ and catF. Thus, the catIJF region, known to exchange genetic information with the pcaIJF region in the same chromosome directing isofunctional proteins associated with the beta-ketoadipate pathway, has avoided the evolutionary forces that conferred characteristics G + C content upon the other ben and cat genes in A. calcoaceticus.

Acinetobacter calcoaceticus↗

PubMed1990

Heparin effect on bone density.

In order to provide estimates of the risks of symptomatic osteoporosis and reduced bone density in premenopausal women treated with long-term (greater than 1 month) heparin therapy, we evaluated a cohort of 61 consecutive premenopausal women previously treated with long-term heparin (cases) and a group of controls matched for age, parity and duration between the last pregnancy and evaluation. All patients underwent dual photon absorptiometry of the lumbar spine and single photon absorptiometry of the wrist and most cases underwent plain lateral radiography of the thoracolumbar spine in order to exclude silent fractures. Although none of the cases suffered symptomatic fractures (0 of 61, 95% confidence intervals 0.0 to 5.9%), there was a significantly greater proportion of cases than controls with bone density below our pre-defined levels. The long-term implications of our findings are uncertain but because it is possible that the reduction in bone density predisposes women to fractures, this potential risk should be considered when treating women with long-term heparin.

Adult↗

PubMed1989

Intermittent compression units for the postphlebitic syndrome. A pilot study.

The postphlebitic syndrome is a common affliction with limited therapeutic options. Patients who fail to respond to treatment with graded elastic compression stockings often develop a chronic pain syndrome manifested by intractable pain and swelling. Because lymphedema, a condition also associated with leg pain and swelling, has been successfully treated by intermittent compressive therapy with an extremity pump, we conducted a pilot study of compressive therapy in patients with severe postphlebitic syndrome. All five patients studied had dramatic improvement in symptoms and functional status without side effects. Although a large randomized trial is needed to properly evaluate compressive therapy, it appears to be very effective in selected patients.

Adult↗

PubMed1989

Heparin therapy during pregnancy. Risks to the fetus and mother.

The true maternal and fetal risks of heparin therapy during pregnancy are unknown, because most published studies are small and do not report consecutively treated patients. In order to address these issues, we performed a retrospective cohort study of 100 pregnancies in 77 women treated with heparin during pregnancy. In 98 pregnancies heparin therapy was given for the prevention or treatment of venous thromboembolism; in the remaining 2, because of prosthetic heart valves. The rates of prematurity, abortions, stillbirths, neonatal deaths, and congenital abnormalities were similar to those in the normal population. There were two bleeding episodes and no symptomatic thrombotic episodes associated with heparin therapy. We conclude that maternal heparin therapy is safe for the fetus and is associated with an acceptable bleeding rate and a low rate of thrombotic recurrence in the mother.

Abnormalities, Drug-Induced↗