Antiproliferative effects of heparin on normal and transformed NIH/3T3 fibroblasts.

We studied the effect of heparin on proliferation and signalling in normal NIH/3T3 fibroblasts, and in cells transformed by different oncogenes. Heparin inhibited the proliferation of normal as well as of v-sis and v-erbB transformed fibroblasts in the presence of serum, but failed to inhibit v-erbB-driven proliferation in serum-starved cultures; under these conditions, heparin inhibited by approximately 50% the proliferation of normal and v-sis- transformed cells. Heparin also inhibited PDGF-induced cell proliferation and inositol lipid turnover in v-sis transformants, but it did not affect PDGF mitogenic signalling in NIH/3T3 fibroblasts.     

Immunological responses in patients with tuberculosis and in vivo effects of acetyl-L-carnitine oral administration

Tuberculosis (TBC) is characterized by a complex immune response which parallels the clinical course of the disease. In this respect, acquired resistance, delayed hypersensitivity reaction and anergy are the main types of immune reactivity to mycobacterial antigens. In view of the presence of nonspecific and specific immune deficits in TBC patients, a clinical trial was carried out in a group of 20 individuals with active pulmonary TBC by oral administration of acetyl-L-carnitine (ALC). This drug, which has been shown to possess immunomodulating activities, was able to upregulate the T-dependent antibacterial activity in TBC patients after 30 days' treatment, while the same activity decreased in patients receiving placebo only. On the other hand, ALC did not modify serum levels of tumour necrosis factor-alpha, in the same individuals. This cytokine plays a detrimental rather than beneficial role in TBC pathogenesis. In the light of these data, ALC seems to be a powerful immunomodulator in the course of Mycobacterium tuberculosis infection and other mycobacteriosis.     

On-line membrane inlet mass spectrometry for feed-back control of precursor concentration in penicillin fermentation

Summary A sampling system which enables on-line measurements of the precursor phenoxyacetic acid (POAA) in penicillin fermentation by membrane inlet mass spectrometry is presented and its capacity for feed-back regulation of POAA to a low predefined concentration in a penicillin-V fermentation over 150 hours is demonstrated. The system measures alternately filtered sample and standard solution in a measuring cycle which is shorter than the response time of membrane inlet mass spectrometry (MIMS) but sufficiently long to decide whether the concentration of POAA in the sample is higher or lower than in the standard solution at set point concentration. The decision is used for on-off regulation of the addition of POAA.     

Structure determination of N-linked oligosaccharides engineered at the CH1 domain of humanized LL2

Two humanized antibody mutants, hLL2HCN1 and hLL2HCN5, engineeredwith CH₁ domain-appended carbohydrates (CHOs) were generatedto facilitate site-specific conjugation of radionudides andanti-cancer drugs to antibodies. Such site-specific conjugationmay minimize the incidence of immunoreactlvity perturbationas is often observed with random conjugation. Since the compositionsand structures of CHOs are important in determining the chemistry,efficiency, and extent of conjugation, the sequences of theCH₁-appended CHOs were determined by exoglycosidase digestionsand fluorophore-assisted CHO electrophoresis (FACE). The CHOspecies attached at HCN1 and HCN5 sites in hLL2HCN1 and IJLL2HCN5,respectively, were distinct from each other, heterogeneous,and extensively processed. All of these CHOs were corefucosylatedcomplex-type oligosaccharides and contained Gal (galactose)and GlcNAc (N-acetylglucosamine) residues in the outer branches.Some of the outer branches were composed of Gal     

Sensitivity of Escherichia coli acrA mutants to psoralen plus near-ultraviolet radiation

The sensitivity to psoralen plus near-ultraviolet radiation (PUVA) was compared in a pair of E. coli strains differing at the acrA locus. Survival was determined for both bacteria and phage lambda. AcrA mutant cells were 40 times more sensitive than wild type to the lethal effect of PUVA. Free lambda phage exposed to PUVA survived as well when plated on acrA mutants as on wild type. In contrast, prophage lambda CI857 ind carried in lysogenic acrA strains was hypersensitive to PUVA. The enhanced sensitivity of bacterial and lambda DNA, when inside acrA cells, was paralleled by an increased photobinding of radiolabelled psoralens in the mutant. Binding was increased specifically to DNA rather than to nucleic acids in general. The difference in psoralen-binding ability determined by the acrA gene persisted after permeabilizing treatment of the cells. The results suggest that the acrA mutation causes an alteration specifically in the environment of the cellular DNA so as to allow increased intercalation and photobinding of psoralens.     

Congenital malformations in Utah

The rate of malformed children in Utah of 11.7 per 1,000 liver births, derived from 128,857 birth certificates, ws not high compared with other non-Utah studies. Rates of selected malformations also were not high. The rate of malformed children varied by county of residence. San Juan County reported the highest percentage of mothers receiving late or infrequent prenatal care, the lowest mean level of public education, and the highest rate of malformed children in the state. The rate was not significantly associated with the large population of Indians residing in that county since by controlling for residence, the variation by race was eliminated. The overall rate was positively associated with maternal age rimarily due to an increased frequency of Down's syndrome. The impact of the "maternal age effect" on the state malformation rate, however, was not large. By controlling for maternal age, the slight association between increased rate of malformed children and increasing birth order was eliminated. The rate of malformed children was higher for parents having a low level of education, infrequent prenatal care, or who were not married. There was also a strong negative association of birth weight with the rate of malformation. Analysis of rates of selected malformations suggested that the low birth weight was a sequela to intrauterine growth retardation caused by severe congenital malformation. The validity and etiologic implications of these results await further investigation.     

A noncycling activity assay for the omega subunit of Escherichia coli RNA polymerase.

We describe a new method for quantitatively assaying the omega subunit of Escherichia coli RNA polymerase. The assay is based on the ability of RNA polymerase holoenzyme to catalyze the continuous synthesis of the dinucleotide pApU on a poly[d(A-T)] . poly[d(A-T)] template when supplied with AMP and UTP as substrates. Core enzyme, lacking omega subunit, catalyzed this reaction at a rate less than 1% that of holoenzyme. The omega subunit was not released from the enzyme/DNA complex during dinucleotide synthesis. Using this assay, a titration of a fixed concentration of core enzyme was observed with increasing concentrations of added omega subunit. Below a 1:1 omega:core ratio the measured activity increased linearly with omega concentration, whereas above a 1:1 ratio the activity remained constant. An immediate application of the assay is in determining the concentration of active omega, or equivalently of active holoenzyme, in any RNA polymerase preparation.     

Sterols from three Lactarius species

The sterol composition of three fungi was determined. Ergosterol is the major sterol, accompanied by other closely related sterols.