Transcriptional properties of genomic transgene integration sites marked by electroporation or retroviral infection

As a possible consequence of their survival strategy, proviruses are predominantly found in transcription-promoting genomic sites. For certain applications, these findings have led to the preferential use of retroviral vectors for the stable integration of transgenes. This study demonstrates that transcription levels of single-copy proviruses, which have been established either by infection or by single-copy transfection (electroporation), are rather comparable. Therefore, electroporation is suggested as an alternative gene transfer route in cases where the use of infectious retroviral vehicles is to be avoided due to safety considerations. A difference between clones derived from these two gene transfer routes concerns the inactivation pattern which, for electroporated clones, is an exclusive property of the low expressers. This difference may be due to the nature of the illegitimate recombination event which is thought to be less invasive if catalyzed by the retroviral integrase. Substantial differences between infection and Ca phosphate-mediated transfection that have been reported earlier are explained by the respective transfection parameters.

[The sonographic picture of an echogenic liver is an indicator of pathologic glucose tolerance]

BACKGROUND

Almost all patients in departments of internal medicine routinely undergo abdominal ultrasound examination in which liver changes indicating hepatic steatosis are often detected. The aim of this study was to assess the occurrence of pathological oral glucose tolerance, manifest diabetes mellitus and other changes indicative of a metabolic syndrome in patients with sonographic signs of hepatic steatosis.

PATIENTS AND METHODS

577 patients were examined during a period of 6 months: 90 patients fulfilled the inclusion criteria.

RESULTS

Among the 90 patients with echodense liver who were included in the study (42 female, 48 male) 36 patients presented with previous diagnosis of diabetes mellitus (40%). The oral glucose tolerance test was impaired in 19 patients (21%) and in four patients with manifest diabetes mellitus (4%). Among patients with echodense liver a high percentage presented with obesity and impaired fat metabolism.

CONCLUSIONS

The large number of patients with an impaired oral glucose tolerance test converting to manifest diabetes, as well as the large number of patients with manifest disorders of fat metabolism suggest that screening for diabetes should be performed in patients who present with sonographic signs of hepatic steatosis.

Dissociative recombination of HD+ in selected vibrational quantum states

Rate coefficients for dissociative recombination of HD+ in selected vibrational states have been measured by a combination of two molecular fragment imaging methods by using the heavy-ion storage ring technique. Recombination fragment imaging yields state-to-state reaction rates. These rates are converted to rate coefficients by using vibrational level populations of the stored ion beam, derived from nuclear coordinate distributions measured on extracted ions. The results show strongly increasing rate coefficients for high vibrational excitation, where additional dissociation routes open up, in agreement with a theoretical calculation. Very low rate coefficients are found for certain, isolated vibrational states.

Erythropoietin response to anemia as a function of age

The erythropoietin (EPO) response to anemia was assessed for 244 subjects aged 1-64 years (mean 45.2 years) and 121 subjects aged 65-94 years (mean 68.3 years). Subjects included non-anemic individuals as well as those with anemia of various etiologies, excluding renal disease and pregnancy. Significant inverse correlations between serum immunoreactive EPO and hematocrit were noted for both groups. Regression lines failed to show a significantly lower slope or y-intercept for older compared to younger subjects. EPO levels were not significantly lower for older compared to younger subjects when controlled for hematocrit level. These results suggest that the EPO response to anemia in older subjects is similar to that of younger subjects.

Insulin-mediated and non-insulin-mediated metabolic effects of gastroenteropancreatic peptides in type I and type II diabetes

In this brief review of regulatory function of gastroenteropancreatic peptides in control of intermediary metabolism in normal and diabetic states, with and without mediation by insulin and/or glucagon, a variety of possible mechanisms have been described. It is apparent that the pharmacologic actions of the peptides identified in various locations provide models for multiple routes of delivery and modes of action of effectors in this control system. Examples already exist of each of the hypothetical mechanisms illustrated in the scheme in Figure 4. It is clear that a great deal of study will be necessary in identification of the active agents and assessment of their importance in the physiology of intermediary metabolism. With respect to the possible pathophysiologic roles of regulatory peptides of the gastroenteropancreatic system other than insulin and glucagon, a number of considerations of Type I and Type II diabetes have been raised. The balance of the evidence suggests that Type I diabetes may be viewed as an insulin deficiency syndrome, so that physiological replacement with insulin may be expected to result in correction of the metabolic abnormalities. Nevertheless, the difficulty of physiologic replacement treatment, which may call for portal delivery of insulin, is well recognized, and abnormalities secondary to insulin deficiency even in "well-treated" Type I diabetes may be compounded by the effects of gastroenteropancreatic peptides other than insulin, exerted through the various mechanisms discussed. In Type II diabetes mellitus, current understanding of the pathophysiology is much less complete and no convincing description of the etiology exists. The various metabolic actions of the gastroenteropancreatic peptides, and their interactions with other endocrine, paracrine and nervous regulatory mechanisms, represent a dauntingly complex control system. The elucidation of this system can provide fertile ground for the development and testing of hypotheses for the pathophysiology of disordered metabolism in Type II diabetes mellitus.

Isolation and partial characterization of ovine lactoferrin

Ovine lactoferrin was isolated by ammonium sulfate precipitation and ion exchange chromatography. Comparative analyses were performed with the bovine protein. Differences in the amino acid compositions and the tertiary structure of the proteins were observed.

Deoxyribonucleic acid polymerase from Physarum polycephalum. Properties of the major cytoplasmic activity in exponentially growing microplasmodia

DNA polymerase was purified 1000-fold from the cytoplasm of microplasmodia of the myxomycete Physarum polycephalum. The activity was found in two forms exhibiting molecular weights of 204000 and 116000 respectively. Both forms eluted together from DNA-cellulose and DEAE-Sephadex columns. The Stokes radii were 6.5 and 5.5 nm. The sedimentation coefficients were 7.6 and 5.2 S. The frictional ratios of 1.69 suggest a highly hydrated and/or an asymmetric structure of the molecule. The enzyme-catalyzed reaction was sensitive to N-ethylmaleimide (60% inhibition by 1 mM). Unlike DNA polymerase alpha from mammalian cells the Physarum enzyme was stimulated by 30 mM NaCl. Activated DNA was the preferred template. Poly(A) . (DT)12 was not accepted. The Km value for deoxynucleoside triphosphates was 3 micron, for activated DNA 50 microgram/ml and for Mg2+ at the optimum [k+] of 150 mM about 0.6 mM.

Genetic factors and malaria in the Temuan

The jungle habitat of the Temuan aborigines harbors a variety of infectious diseases, the most notable being malaria. Our study of 15 genetic systems in the Temuan revealed substantial polymorphism and within-population genetic diversity. The polymorphisms for Hb beta, G6PD, and El are of interest in regard to genetic adaptation to malaria. Among the polymorphisms investigated we conclude that G6PD deficiency and elliptocytosis are likely to have malaria-resistant effects as evidenced by their low association with malarial parasitemia or their higher frequency in adults than in children. These findings suggest that the malarial habitat of the Temuans is livable in the long range sense for them because of the cluster of malaria-resistant alleles in their gene pool (G6PD)-, El, and possibly, but not tested here because of its low frequency, Hb beta E). The same condition probably holds for the Semai, the nearest aborigine neighbors of the Temuan (although the Semai have not been tested for malarial parasitemia and for these polymorphisms simultaneously), since the Semai have substantial Hb betaE, G6PD-, and El. The Temuan have a cultural identity system of rituals, beliefs, and certain aspects of language which effectively isolates them genetically from Malays and other nonaborigines. This system hinders the dilution of the malaria-resistant alleles of the Temuan gene pool with the malaria-susceptible alleles of the nonaborigine gene pools.

Hemoglobin Constant Spring (slow-moving hemoglobin X components) and hemoglobin e in Malayan aborigines

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