Modulation of oestrone sulphatase activity in breast cancer cell lines by growth factors

Currently there is much interest in the role that growth factors may play in the development of human breast tumours. We have shown previously that growth factors secreted by breast tumours may influence the activity of oestradiol hydroxysteroid dehydrogenase, the enzyme which catalyses the interconversion of oestrone (E1) and oestradiol. As the formation of E1 from its sulphate (E1S) by oestrone sulphatase may be quantitatively more important than production from androstenedione via aromatase, we have studied the effect of insulin-like growth factor-1 (IGF-I) and basic fibroblast growth factor (bFGF) on oestrone sulphatase activity in the hormone-dependent MCF-7 and the hormone-independent MDA-MB-231 breast cancer cell lines. In both these cell types, bFGF (1-200 ng/ml) and IGF-I (25-200 ng/ml) significantly stimulated oestrone sulphatase activity in a dose-dependent manner (by 8-60%) after 48 h. Additionally, cycloheximide significantly inhibited (by 90-120%) this stimulation of oestrone sulphatase activity by the two growth factors in both MCF-7 and MDA-MB-231 cells. Basal oestrone sulphatase activity was higher in the oestrogen receptor, ER-ve MDA-MB-231 cells than in the ER + ve MCF-7 breast cancer cells. We conclude that these growth factors, believed to be secreted by breast tumours, may induce enzymes of oestrogen synthesis and hence increase local production of oestrogens.

Glomus tumor of the coccyx. A curable cause of coccygodynia

A 30-year-old woman presented with recurrent severe coccygodynia. She underwent exploration for a possible pilonidal sinus and was found to have a precoccygeal glomus tumor that also involved bony trabeculae of the coccyx. To our knowledge, a glomus tumor involving the coccygeal bone has not been previously documented. In view of the relief of this patient's pain following the surgical excision of coccyx and tumor, a causal role is suggested.

Control of developmental transcription factor sigma F by sporulation regulatory proteins SpoIIAA and SpoIIAB in Bacillus subtilis

The sporulation operon spoIIA of Bacillus subtilis consists of three cistrons called spoIIAA, spoIIAB, and spoIIAC. Little is known about the function of spoIIAA and spoIIAB, but spoIIAC encodes a sigma factor called sigma F, which is capable of directing the transcription in vitro of genes that are expressed in the forespore chamber of the developing sporangium. We now report that the products of the spoIIA operon constitute a regulatory system in which SpoIIAA is an antagonist of SpoIIAB (or otherwise counteracts the effect of SpoIIAB) and SpoIIAB is, in turn, an antagonist of SpoIIAC (sigma F). This conclusion is based on the observations that (i) overexpression of spoIIAB inhibits sigma F-directed gene expression, (ii) a mutation in spoIIAB stimulates sigma F-directed gene expression, (iii) a mutation in spoIIAA blocks sigma F-directed gene expression, and (iv) a mutation in spoIIAB relieves the block in sigma F-directed gene expression caused by a mutation in spoIIAA. The SpoIIAA/SpoIIAB/SpoIIAC regulatory system could play a role in controlling the timing of sigma F-directed gene expression and/or could be responsible for restricting sigma F-directed gene expression to the forespore chamber of the sporangium.

The synthesis of polyamide-oligonucleotide conjugate molecules

We have developed methods for the synthesis of peptide-oligodeoxyribonucleotide conjugate molecules in particular, and polyamide-oligonucleotide conjugates in general. Synthesis is carried out by a solid-phase procedure and involves the assembly of a polyamide on the solid support, conversion of the terminal amino group to a protected primary aliphatic hydroxy group by reaction with alpha, omega-hydroxycarboxylic acid derivatives, and finally oligonucleotide synthesis using phosphoramidite chemistry. The conjugate molecules can be used as DNA probes, with the polyamide component carrying one or more non-radioactive markers. These conjugates also have the potential to be used as anti-sense inhibitors of gene expression, with the peptide segment acting as a targeting moiety.

The preparation of polyamide-oligonucleotide probes containing multiple non-radioactive labels

Oligonucleotide probes containing multiple non-radioactive labels have been prepared by utilising and extending the methods used to prepare polyamide-oligonucleotide conjugates. The probes were prepared by incorporating suitable amino acid residues, such as lysines, in the polyamide, which were then used as sites for the attachment of the non-radioactive labels. The procedures developed give control over the distance of the label from the oligonucleotide, and also the inter-label distance. The labels can be conveniently introduced while the substrate is still on the solid support. Even though fluorescent oligonucleotide probes prepared in this way carrying multiple carboxyfluorescein labels gave low levels of fluorescence due to quenching, the probes containing ten biotin labels gave a detection sensitivity of approximately 5 attomole (3 million molecules).

The National Breast Screening Study: pre-recruitment sources of awareness in participants

Data collected by questionnaire from 89,835 women on entry into 15 Canadian National Breast Screening Study (NBSS) centres reveal pre-recruitment sources of awareness: radio and television were reported by 30%; workplace 6%; friends 35%; physician 6%; and other by 23% of respondents. Personalized letters of invitation employed in 5 centres were an important source of awareness. In the age group recruited, 40-59 years, age had no influence on the source reported. However women with post-secondary school education were less likely to report radio and television as a source and more likely to report newspapers compared to women with less education. Women with only public school education were less likely to report the workplace as a source of awareness than women with post-secondary education. Recruitment strategies for screening programs may be more successful if publicity on radio and television is geared to women of lower educational status and if publicity in newspapers is geared to women of higher educational status, supplementing both with personalized letters of invitation.

Heterologous 5' flanking regions do not support in vitro template activity of a Drosophila melanogaster tRNA(Val3b) gene

The 5' and 3' structure of a Drosophila tRNA(Val3b) gene was investigated to examine the defect which caused the extremely low in vitro transcription template activity of the gene. Recombinant genes were constructed linking 5' and 3' flanking regions from tRNA genes which were active in vitro templates (tRNA(Val4), tRNA(Arg), tRNA(Ser7)) to the tRNA(Val3b) gene. None of the recombinant genes were effective in vitro templates. The defect in tRNA(Val3b) was demonstrated to reside in the 5' flanking region of the gene and deletion analysis indicated that no specific transcription inhibitor sequence was present 5' to the gene. The data suggest that the effect of 5' flanking sequences on in vitro transcription of the tRNA(Val3b) gene requires a specific relationship between the tRNA gene and the flanking sequence.

Distinct epitopes recognized by I-Ad-restricted T-cell clones within antigenic site E on influenza virus hemagglutinin

A total of 14 I-Ad-restricted helper T-cell clones specific for the hemagglutinin (HA) molecule of influenza virus were isolated from spleens of BALB/c or (BALB/c X C57BL/10)F1 mice immunized with the H3 subtype influenza virus A/Memphis/71 (Mem 71) and from lymph nodes of BALB/c mice primed with purified HA. The specificity of these T-cell clones was assessed in proliferation assays by reactivity with naturally occurring strains of viruses that arose by antigenic drift and contain known amino acid sequence changes in HA and with a panel of monoclonal antibody (MAb)-selected mutants of Mem 71 with single amino acid substitutions in HA. The HA genes of those mutant viruses that failed to stimulate one or more of the T-cell clones were sequenced. The clones could be allocated to at least four groups, each group having a distinct pattern of reactivity with the panel of natural field strains. The epitopes recognized by the four groups of clones were found, by reactivity with MAb-selected mutants, to be in very close proximity to one another and probably overlapping. All of the distinct epitopes recognized by the T-cell clones were adversely affected by a single amino acid substitution, either at residue 60 or at residue 63 in the HA1 polypeptide chain, within the region known from antibody-binding studies as site E. Some, but not all, of the epitopes may be influenced by the addition of a carbohydrate side chain to the HA of a particular MAb-selected mutant and certain field strains containing an Asp----Asn substitution at residue 63. Site E is therefore a major site of H-2d helper T-cell recognition on the H3 HA.

Analysis of the time of day of onset of menstruation

The exact time of day of onset of menstruation was studied in 86 women over 4-6 cycles. Detailed information on the time of retiring the previous night, time of rising in the morning, time of onset of premenstrual spotting and time of onset of any menstrual cramps was obtained from 48 of these women. A significantly greater number of cycles (70.4%) commenced during the night or in the first 4 h after rising, compared with later in the day. In a large proportion of these (29 out of 76), blood was noted to be present on waking, menstruation thus having begun at some time during the hours of sleep. Premenstrual spotting of greater than 3 h duration was more common than expected and was noted by 67% of women. Onset of menstrual cramps was fairly evenly distributed closely either side of commencement of menstruation proper in the 50% of women who experienced them. In only 13% of women studied did bleeding commence within the same 3-hour time interval in each of four cycles, and almost 50% demonstrated a very wide variation with onset at almost any time of day.

Partial purification of stable transcription complexes with cloned tRNA genes of Drosophila melanogaster

The specific transcription of a cloned Drosophila melanogaster tRNAVal4 gene and a tRNASer7 gene by extracts from a homologous embryonic cell line showed lag periods of about 30 min before maximum rates were reached. This lag appeared to represent the time to form an active transcription complex. Thus, when extracts were incubated with template DNA for 30 min at 22 degrees C and stored in the cold, the subsequent transcription rate was linear with time and without a lag. After ultracentrifugation of a preincubated reaction mixture on a sucrose step gradient consisting of 20, 30, 40, and 60% shelves, about 40% of the transcription activity in the extract was found in the 40% shelf. This fraction formed almost exclusively RNA I, the unprocessed tRNA gene transcript, and transcription required only addition of ribonucleoside triphosphates. The rate of formation of RNA by the 40% sucrose fraction was linear against time, with no lag, and linear with the quantity of fraction. The yield of activity isolated on the gradient was directly proportional to the quantity of cloned gene in the preincubation mixture. At a limiting concentration of the gene in the preincubation mixture, the turnover number of the isolated complex was approximately 50 transcripts/gene/h. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of fractions containing the complex still showed many bands, although the complex activity was greatly purified compared to the extract. From the sedimentation behavior of the isolated active transcription complex and from its stability and transcriptional properties, we conclude that the 40% sucrose fraction contains an active transcription complex containing a cloned tRNA gene, RNA polymerase III, and the accessory protein factors required for transcription.

Rat diaphragm: changes in muscle fiber type frequency with age

This study demonstrates age-related changes in fiber type, distribution, and diameter that suggest that the diaphragm does not attain a static pattern of fiber type in adults. Furthermore, the progressive increase in the FG fiber diameters may be of importance in the interpretation of physiologic and biochemical parameters measured in the diaphragm muscle of animals of different age groups.

Effect of zinc deficiency on muscle fibre type frequencies in the post-weanling rat

Male weanling rats were maintained on diets either deficient or adequate in zinc for a period of 4 weeks. The rats on the deficient diet showed a reduction in food intakes and growth. After 4 weeks both soleus muscles and the lateral portion of the diaphragm were studied histochemically to examine the relative frequencies of the fibre types. The soleus muscles of the deficient animals showed a significant change in the proportion of slow and fast fibres. The diaphragm muscles of the deficient animals had a significant increase in the proportion of fast-twitch oxidative glycolytic fibres and a significant decrease in fast-twitch glycolytic fibres compared with the controls. Stainable lipid increased in the diaphragm muscle of the deficient animals with respect to their pair-fed controls.

Mitochondrial abnormalities in muscle from vitamin B12-deficient sheep

Skeletal and cardiac muscles from vitamin B12-deficient sheep were examined. Histochemical studies did not reveal any gross pathological changes in the muscle structure, but there was an abnormal distribution of the product of the NADH-diaphorase reaction. Electron microscopy revealed an abnormal distribution of mitochondria, changes in the number and arrangement of cristae within the mitochondria and the presence of inclusions. The possibility that alterations in mitochondrial morphology are early lesions attributable to metabolic changes in vitamin B12 deficiency is discussed.

Thiaminase activity in the gut of cobalt-deficient sheep

In an attempt to clarify the reported relationship between cobalt deficiency and the incidence of cerebrocortical necrosis (CCN), sheep were fed on a diet deficient in cobalt. High levels of thiaminase activity were found regularly in rumen and faeces samples from cobalt-deficient animals, and also from controls supplemented with cobalt or vitamin B12. There was a poor correlation between thiaminase activity and viable counts of the thiaminase-producing organisms Clostvidium spovogenes and Bacillus spp. Urinary excretion of thiamine appeared normal. When the sheep were killed, normal concentrations of thiamine were found in the liver. The sheep were deficient in vitamin B12, as judged by the concentrations in serum and liver, by urinary excretion of methylmalonic acid, and by clinical condition. Twitching and weakness were observed, but clinical signs of CCN did not develop.

Transcription of cloned transfer RNA genes from Drosophila melanogaster in a homologous cell-free extract

Cloned Drosophila melanogaster tRNA genes have been transcribed in a homologous cell-free extract isolated from a Schneider II cell line. The major product of the reaction is a tRNA precursor which is processed to a tRNA sized species. The kinetics of transcription has been followed for 5 different valine tRNA gene clones. The results demonstrate formation of stable transcription complex with at least two kinetic steps. While the rate of formation of the transcription complex is similar to different clones, the ultimate rate of transcription varies dramatically. Comparison of the DNA sequence of the tRNA genes suggests that rate determining nucleotides lie outside the canonical tRNA split-internal promoters.

Inflatable bath for external cooling

The authors describe an inflatable bath which can be used rapidly and safely, with a minimum of patient manipulation, for external cooling of hyperthermic patients or in the elective induction of hypothermia. This device permits ready access to the patient so that monitoring and treatment can be carried on while cooling is in progress and is particularly adopted to use in the operating room.