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Biomedical subjects

B J McCarthy

Publications and source records attributed to B J McCarthy.

At least 91 records · Page 5Linked to original sources
PubMed1982

DNA sequence analysis of a mouse pro alpha 1 (I) procollagen gene: evidence for a mouse B1 element within the gene.

In a 3.8-kilobase mouse DNA sequence encoding amino acid sequences for the pro alpha 1(I) chain of type I procollagen, 14 coding sequences were identified which specify a sequence 95% homologous to amino acid residues 568 to 963 of the bovine alpha 1(I) chain. All of these coding sequences were flanked by appropriate splice junctions following the GT/AG rule. These observations suggest, but do not prove, that this pro alpha 1(I) gene is transcriptionally active. Of the 14 coding sequences, 7 were 54 base pairs in length, whereas the remainder were higher multiples of 54 base pairs. Nonrandom utilization of codons pertained throughout all of the coding sequences showing a preference (56%) for U in the wobble position. Two of the intervening sequences encoded imperfect vestiges of coding sequences which exhibited a codon preference different from that of the pro alpha 1(I) gene proper and were not flanked by splice junctions. One intervening sequence encoded a member of the mouse B1 family of middle repetitive sequences. It was flanked by 8-base-pair direct repeats and had a truncated A-rich region, suggesting that it may be a mobile element. Within this element were sequences which could function as a RNA polymerase III split promoter.

Animals↗
PubMed1982

Age at onset of necrotizing enterocolitis: an epidemiologic analysis.

We studied the epidemiologic interrelationships among birth weight, gestational age, and age at onset of necrotizing enterocolitis of the newborn. As birth weight increased, the range of ages at onset and the mean age at onset both decreased. Weekly birth weight-specific attack rates for necrotizing enterocolitis declined sharply in all birth weight groups when the equivalent of 35-36 wk gestational age was reached. Our data are consistent with the hypothesis that the risk period for necrotizing enterocolitis is determined primarily by the maturity of the gastrointestinal tract of the newborn.

Age Factors↗
PubMed1982

Defining legitimate births in Fulton County, Georgia, 1977.

In 1977, the parents of 1,043 births recorded for 15 to 19 year old women in Fulton County, Georgia, were classified as married. However, only 36 per cent of these births could be linked with marriage certificates. An analysis of the unlinked birth certificates showed that the overwhelming majority of teenage parents did not appear to be legally married. The absence of a specific statement regarding marital status on birth certificates results in inaccuracies in the reporting of births according to marital status of parents.

Adolescent↗
PubMed1981

The epidemiology of neonatal death in twins.

The epidemiology of twin pregnancies was studied with the use of data on 7,001 live-born twins from the Georgia neonatal surveillance network for the period 1974-1978. A cesarean section did not appreciably reduce the risk of neonatal death for a twin with a vertex presentation. The relative risk of such a neonatal death was 1.4 after adjustment was made for birth weight. A cesarean section did improve the outcome for breech and other presentations. Twins had a sixfold higher neonatal mortality rate than had singleton infants (p less than 0.001), which can be explained on the basis of distribution of birth weights. Twins had a weight-specific mortality rate equivalent to or significantly less than that for singletons after adjustment was made for birth weight. The relative risk of neonatal death for Twin 2 compared with Twin 1 was not significant. Breech presentation was more common in twins than in singletons, and for Twin 2 more than for Twin 1. As birth weight increased, the number of breech presentations decreased for Twin 2 but not for Twin 1. To reduce the high neonatal mortality rate for twins, the objective should be to reduce the incidence of low-birth-weight twins, rather than to increase the cesarean section rate for them.

Birth Order↗
PubMed1981

Cloned complementary deoxyribonucleic acid of Drosophila cells. Relationship of genome copy number to messenger ribonucleic acid abundance.

Recombinant DNA plasmids containing DNA sequence complementary to poly(adenylic acid) [(poly(A)] containing RNA from the cytoplasm of Drosophila Kc tissue culture cells were constructed. The reiteration frequency in the genome of the RNA homologous to the 20 randomly selected clones was determined by two rapid methods. Of the 20, 17 were determined to be single copy, 2 were repeated several (2-4) times, and 1 was repeated approximately 10 times. The steady-state level of mRNAs homologous to the 20 cDNAs was quantitated and varied more than 160-fold. The RNAs ranged from 0.16% to less than 0.001% of the poly(A)-containing RNA.

Animals↗
PubMed1981

Maternal death after cesarean section in Georgia.

Few reliable data exist on the risk of maternal death from cesarean section. To identify more deaths after cesarean section than reported by vital records alone, we linked data from Georgia resident live-birth certificates to those from death certificates of Georgia women aged 10 to 44 years. We found 16 maternal deaths after cesarean section in Georgia during 1975 and 1976, five more (45%) than the 11 reported through vital records alone. We attributed nine of these 16 deaths to the cesarean section per se. We than calculated a total death-to-case rate of 105.3 deaths per 100,000 cesarean sections and a rate attributable to cesarean section of 59.3 deaths per 100,000 procedures. Pulmonary embolism and cardiopulmonary arrest during general anesthesia were the leading causes of death in this series. Preventive measures aimed at reducing these complications may reduce deaths after cesarean section.

Adolescent↗
PubMed1981

DNA sequence of a plasmid-encoded dihydrofolate reductase.

The sequence of the methotrexate-resistant dihydrofolate reductase (DHFR) gene borne by the plasmid R-388 was determined. The gene was subcloned and mapped by an in vitro mutagenesis method involving insertion of synthetic oligonucleotide decamers encoding the BamHI recognition site. Sites of insertion that destroyed the methotrexate resistance fell in two regions separated by 300 bp within a 1.2 kb fragment. One of these regions encodes a 78 amino acid polypeptide homologous to another drug-resistant DHFR. The second region essential for DHFR expression appears to be the promoter of the DHFR gene.

Base Sequence↗
PubMed1981

Identification of a Balb/c mouse pro alpha 1(I) procollagen gene: evidence for insertions or deletions in gene coding sequences.

We report the first isolation and identification of a mouse genomic fragment encoding amino acid sequences for the pro alpha 1(I) chain of type I procollagen. The DNA sequence of eight coding sequences is presented; five of these are 54 bp and three are 108 bp in length. Together these specify 198 amino acids which are 94% homologous to the corresponding bovine pro alpha 1(I) chain protein sequences. Each of the eight coding sequences is flanked by appropriate splice-junction sequences that exhibit considerable sequence complementarity to the rat small nuclear U1a RNA. In the 198 codons examined in this mouse genomic clone, the preferred codons for glycine and alanine are GGU (46/67) and GCU (23/30), respectively. This is in contrast to the codon usage reported for the chicken pro alpha 1(I) cDNA clone (Fuller and Boedtker, 1981). The examined coding sequences exhibit considerable nucleotide homology in both end-to-end and in staggered alignments. Based on an analysis of this homology data, a model is presented for the generation of 108-bp coding sequences from 54-bp units by two successive homologous recombinational events within coding sequences. Alternatively, the 108-bp units may have arisen by precise deletions of an intervening sequence between 54-bp coding sequences. Evidence supporting this is provided by a comparison of pro alpha 1(I) and pro alpha 2(I) genes. In the mouse pro alpha 1(I) gene amino acids 856-891 are encoded in a 108-bp unit; the chicken pro alpha 2(I) gene these residues are encoded in two 54-bp coding sequences. In addition, the coding sequences for nearly 50% of the alpha domain are condensed in the pro alpha 1(I) gene into a region approximately one half the size occupied by the comparable sequences in the pro alpha 2(I) gene.

Amino Acid Sequence↗
PubMed1981

Epidemiologic characteristics of necrotizing enterocolitis: a population-based study.

The authors studied retrospectively the epidemiologic characteristics of necrotizing enterocolitis occurring among Georgia infants born during 1977 and 1978; 148 cases of necrotizing enterocolitis were identified. The highest incidence rate for necrotizing enterocolitis occurred among infants weighing 751-1000 g at birth and declined with increasing birth weight to less than 0.2 cases per 1000 live births among infants weighing more than 2500 g at birth. The overall incidence rate for blacks was significantly greater than that for whites (1.6 vs. 0.5 cases per 1000 live births, p = 0.01). The overall case fatality ratio was 38.5%; there were no differences in these ratios between blacks and whites. Necrotizing enterocolitis accounted for 15% of all deaths after the first week of life for infants weighting 1500 g or less at birth. If Georgia incidence rates and fatality ratios are applied to 1978 US births, it is estimated that 2210 cases of necrotizing enterocolitis with over 900 associated deaths would have occurred.

Birth Weight↗
PubMed1981

Child Abuse Registry in Georgia: three years of experience.

The number of reported cases of physical child abuse in Georgia from July 1975 to June 1978 increased. Of 4,292 cases reported, 57% were confirmed. School officials most often reported cases of suspected abuse; 69% were confirmed by social work investigation. Metropolitan black female children had the highest residence/race/sex-specific abuse rates. The highest abuse rate for boys was for the 0- to 3-year-old group, while for girls the highest abuse rates were for the 13- to 16-year-old group. Both natural parents were present in 39% of the confirmed cases, and a natural parent was the abuser in 62% of the cases. Of the natural mothers who were confirmed abusers, 53% had been pregnant as teen-agers. Thirty-eight children died after being abused, with the highest death-case ratio being 62 per 1,000 abused children for black girls aged 0 to 4 years.

Adolescent↗
PubMed1980

Four Drosophila heat shock genes at 67B: characterization of recombinant plasmids.

A 33 kilobase region of the 67B locus of Drosophila melanogaster genome has been isolated. The genes for the 27K, 26K, 23K and 22K heat shock induced proteins are contained within an 11 kb segment. the 27K gene, approximately 1.4 kb in length, and the 23K gene, approximately 1.0 kb in length, are separated by about 1.5 kb of spacer DNA; a third block of transcription, which encodes the 26K gene, is approximately 1.1 kb in length, and is separated from the gene for the 23K protein by 4.5 kb of spacer DNA. The 22K gene is located approximately 1.2 kb from the 26K gene. The RNAs encoding the 27K, 23K and 22K genes are transcribed from the same DNA strand. With the assignment of the four small heat shock induced proteins to 67B, genes for all seven major heat shock induced proteins have no been mapped cytologically.

Animals↗
PubMed1980

Modulation of transcription from chromatin assembled in vitro.

A small plasmid DNA was assembled into chromatin in vitro by incubation in an extract prepared frog eggs of Xenopus laevis. The plasmid DNA contrained the regulatory region of the Escherichia coli lac operon, the transcription of which is under positive regulation by catabolite activator protein (CAP) and negative regulation by lac repressor. After incubation in the egg extract the plasmid DNA acquired approximately 60% of the predicted maximum number of nucleosomes. Chromatin was treated with protein and DNA cross-linking agents prior to transcriptin in order to demonstrate that regions of the DNA organized into nucleosomes served as templates for transcription. Cross-linking abolished transcription of chromatin but had no effect on transcription of the DNA, suggesting that transcription of untreated chromatin was not solely attributable to nucleosome-free regions. In support of this conclusion, the average size of the RNA transcribed from chromatin was approximately 1000 bases, which was approximately 5 times longer than the average distance between nucleosomes. Transcription of in vitro assembled plasmid chromatin by E. coli RNA polymerase was stimulated by catabolite activator protein. The CAP-mediated stimulation of transcription was detectable as an increase in total transcription that was specific to chromatin made from a plasmid containing the lac regulatory DNA sequences. The specific increase in the amount of RNA whose synthesis was initiated within the lac region was demonstrated by hybridization of transcription products to complementary DNA fragments bound to nitrocellulose filters. Preliminary investigation of the action of lac repressor suggested that it also modulated transcription from the chromatin template.

Animals↗
PubMed1980

Evolution of a D. melanogaster glutamate tRNA gene cluster.

We have determined the DNA sequence of a cloned cluster of essentially identical glutamate tRNA genes of D. melanogaster. The cluster consists of five genes: a gene triplet spanning approximately 0.55 kb followed by a 0.45 kb gene doublet 3.0 kb downstream. The genes are all arranged with the same polarity, do not encode the tRNA CCA end and contain no intervening sequences. Examination of the 5' and 3' sequences immediately flanking each gene reveals a striking pattern of sequence homologies between certain of the genes, which suggests a possible evolutionary history of this gene cluster. We propose that two ancestral genes each gave rise to gene doublets by duplication, while one of these gene pairs then gave rise, in turn, to a trio of genes as a result of unequal crossover.

Animals↗
PubMed1980

Multiple actin-related sequences in the Drosophila melanogaster genome.

In this paper we describe the isolation and characterization of a 7.2 kb D. melanogaster chromosomal DNA fragment (K1) which contains nucleotide sequences complementary to D. melanogaster actin mRNA. Plasmid K1 was identified using a Dictyostelium actin cDNA plasmid, B1, as a probe. D. melanogaster mRNA selected by hybridization with immobilized K1 DNA was translated in vitro to yield products which co-migrate with the D. melanogaster actins I, II and III in two-dimensional gel electrophoresis and bind to DNAase I agarose. A physical map localizing restriction endonuclease cleavage sites in the K1 DNA fragment and the direction of transcription is presented. The position of the coding region has been localized by hybridization with labeled B1 DNA and with labeled poly(A)-containing D. melanogaster RNA. On the basis of hybridization of labeled subfragments of plasmid K1 to restriction endonuclease-cleaved D. melanogaster embryo DNA, we conclude that the nucleotide sequence of the presumptive coding region is responsible for labeling of a pattern of multiple restriction fragments from embryo DNA. The chromosomal locus from which DNA fragment K1 is derived has been localized by in situ hybridization to two closely linked bands in the region 88F. Related DNA sequences corresponding to putative actin genes have also been mapped cytologically. These results support the hypothesis that the genes for actin in D. melanogaster are members of a closely related family of coding sequences.

Actins↗
PubMed1980

Sequence of three copies of the gene for the major Drosophila heat shock induced protein and their flanking regions.

The primary sequence of the major heat shock gene of D. melanogaster, that for the 70,000 protein, has been determined. One of the reading frames is devoid of stop codons for over 2000 bp. The region between the first ATG and the first stop codon encodes a protein of molecular weight 70,270. The 5' end of the messenger RNA was localized in the DNA sequence by two independent methods. The 5' flanking sequences of three distinct 70K genes were also determined. Extensive homology in the primary sequences extends about 500 bp upstream from the ATG, which is the presumptive initiation of protein synthesis. Each 70K gene has the putative promoter sequence TATAAATA about 325 bp upstream from this ATG. A heptanucleotide sequence identified as the capping site for other messengers is found 24-30 bp downstream from the ends of the A-T-rich sequence. A 12 bp sequence with dyad symmetry begins 23 bp upstream from the beginning of the above A-T-rich sequence.

Amino Acid Sequence↗
PubMed1980

A dispersed multigene family encoding tubulin in Drosophila melanogaster.

We have used cloned chicken cDNA sequences for alpha- and beta-tubulin to investigate tubulin gene organization in Drosophila melanogaster. Experiments using genomic Drosophila DNA from several sources indicate that there are at least four copies each of the alpha-tubulin gene and the beta-tubulin gene. In situ hybridization experiments show that both the alpha- and beta-tubulin multigene families have dispersed arrangements on the chromosome. Genes for alpha-tubulin have been localized at chromosomal bands 67C, 84B/C, 84D and 85E, while genes for beta-tubulin have been detected at bands 60A/B and 85D. alpha-Tubulin and beta-tubulin chicken cDNA sequences can be used to select a specific mRNA species from a complex mixture which translates in vitro into alpha- or beta-tubulin protein. RNA blot hybridization using the cloned chicken cDNA sequences as probes shows that the alpha- and beta-tubulin messages detected are clearly different in length, with the message for alpha-tubulin measuring approximately 2000 bases and the message for beta-tubulin containing approximately 1800 bases.

Animals↗