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A McCormick

Publications and source records attributed to A McCormick.

At least 55 records · Page 3Linked to original sources
PubMed1990

Regulation of the pituitary-specific homeobox gene GHF1 by cell-autonomous and environmental cues.

Homeodomain proteins function in determination of mating type in yeast, segmentation in fruit flies and cell-type specific gene expression in mammals. In Drosophila, expression of homeobox genes is controlled by cell-autonomous interactions between regulatory proteins and environmental clues. Similar controls may operate during mammalian limb development and frog embryogenesis. But, the exact way in which expression of homeodomain proteins is regulated in these systems is not clear and requires biochemical analysis of homeobox gene transcription. We now describe such an analysis of the GHF1 gene, which encodes a mammalian homeodomain protein specifying expression of the growth hormone (GH) gene in anterior pituitary somatotrophs. GHF1 is transcribed in a highly restricted manner and the presence of GHF1 protein is correlated both temporally and spatially with activation of the GH gene during pituitary development. Analysis of the GHF1 promoter indicates that transcription is also controlled by cell-autonomous interactions involving positive autoregulation by GHF1, and environmental cues that modulate the intracellular level of cyclic AMP and thereby the activity of cAMP response element binding protein (CREB), a ubiquitous transactivator that binds to the GHF1 promoter.

Animals↗
PubMed1989

Estimating the size of the HIV epidemic by using mortality data.

Evidence that more people are dying as a result of HIV infection than is reflected by the number of deaths among reported cases meeting the WHO definition of AIDS is derived from mortality data. Ninety-five causes of death likely to be associated with HIV infection were selected. Standardized mortality ratios due to these causes increased for single men aged 15-54 years from 100 in 1984 to 118 in 1987. The age, sex, marital status, temporal and geographic distribution of these excess deaths suggest that they are HIV-associated. It is estimated that 58% of excess deaths due to HIV-related causes were among cases reported to the CDSC AIDS Surveillance Programme in 1987. Some of these deaths may have been among HIV-positive people who did not meet the WHO definition at the time of death. There is a need for surveillance to be extended to include HIV-positive people who die before meeting the WHO definition if the full extent of the HIV epidemic is to be identified.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Extinction of growth hormone expression in somatic cell hybrids involves repression of the specific trans-activator GHF-1.

Growth hormone (GH) expression in pituitary-derived cells has been attributed to the presence of a positive trans-activator, GHF-1, which binds to two sites on the GH promoter. Somatic cell hybridization of non-GH-expressing L cells with pituitary-derived GH3 cells usually results in extinction of GH production. While previous studies showed that extinction occurs at the level of GH transcription, the exact mechanism remained elusive. We therefore characterized two parental cell lines and three hybrids, two of which extinguish GH expression and one in which GH is reexpressed after loss of mouse chromosomal material. Using in vivo transfections, in vitro transcription, DNAase I footprints, and immunoblotting experiments, no evidence for a direct repressor of GH transcription was found. Rather, extinction of GH expression in fibroblast x pituitary hybrids was accompanied by loss of GHF-1 protein and mRNA expression, suggesting that extinction occurs by repression of this trans-activator.

Animals↗
PubMed1988

Trends in mortality statistics in England and Wales with particular reference to AIDS from 1984 to April 1987.

Death certification should be able to provide accurate data on the number of deaths due to AIDS as a basis for predicting future deaths from the syndrome. Trends in deaths from other causes may identify conditions that have not been recognised to be associated with HIV infection. Mortality statistics with reference to AIDS in England and Wales were completed from death certificates. Increases in deaths from selected causes likely to be associated with AIDS or HIV infection suggested that in some patients with HIV infection, AIDS was not stated on the death certificate or subsequently notified by the doctor who signed the certificate. From calculations of excess deaths between the beginning of 1985 and the end of April 1987, compared with 1984 at least 495 deaths possibly associated with HIV infection were estimated to have occurred among men aged 15-54 during that period. In 261 AIDS or HIV infection was stated on the original or amended death entry as the cause of death, and of these 198 were included in the estimated number of excess deaths. Accurate notification of the underlying cause of death and associated diseases is required for the precise monitoring of trends in mortality from AIDS and possible identification of unrecognised conditions associated with HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Improved bone mineralization and growth in premature infants fed fortified own mother's milk.

"Preterm" human milk fortified with protein (0.85 gm/dL), calcium (90 mg/dL), and phosphorus (45 mg/dL) was compared with unfortified preterm human milk as a feeding for low birth weight infants. Additionally, a special formula for low birth weight infants (Similac Special Care (SC), 20 cal/oz), was compared with a standard 20 cal/oz formula (Similac). Bone mineral content (BMC), as measured by photon absorptiometry, improved in the study groups fed fortified human milk and Similac SC formula during the first 6 weeks of full oral feedings. Even though the intakes of calcium in the groups fed fortified human milk and Similac SC formula approached the intrauterine requirement for Ca during the third trimester of pregnancy (150 mg/kg/d), the values for BMC in these two groups (37 to 39 mg/cm) at the completion of the study were still considerably less than the intrauterine values for radial BMC at 36 to 37 weeks gestational age (72.6 +/- 14.1 mg/cm). Furthermore, the relative phosphorus deficiency (as determined by increased urinary Ca excretion and increased renal tubular reabsorption of phosphate) in the human milk groups occurred with or without supplements of Ca and P. Rate of weight gain in the fortified human milk group was greater than that of the unfortified human milk group and was comparable to that of infants fed Similac SC formula. Rate of weight gain for the unfortified human milk group was similar to that of infants fed Similac formula containing 20 cal/oz. However, none of the four feeding groups exceeded the 50th percentile for weight at the time of discharge (36 to 37 weeks postconceptional age). The results suggest that fortifying preterm human milk with Ca, P, and protein for low birth weight infants will improve bone mineralization and rate of growth to levels comparable to those achieved with a special formula containing high amounts of protein, Ca, and P.

Body Weight↗
PubMed1987

Surveillance of AIDS in the United Kingdom.

The surveillance of cases of the acquired immune deficiency syndrome (AIDS) in the United Kingdom is described and a preliminary analysis made of the 1012 cases that were reported to the end of August 1987. Homosexuals were the largest risk group. For the first time it is possible to present cases by the date of diagnosis and by the regional health authority of residence. The rate of increase of new cases shows no sign of slowing down. One third of patients with AIDS lived in a different regional health authority from that in which their disease had been diagnosed. The geographical distribution varied with the risk group. The commonest presenting clinical feature at diagnosis was Pneumocystis carinii pneumonia. Kaposi's sarcoma was considerably more common among homosexuals than among people in other groups at risk.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Bone mineral content and growth in very-low-birth-weight premature infants. Does bronchopulmonary dysplasia make a difference?

It is reported that very-low-birth-weight (VLBW) infants with the complication of bronchopulmonary dysplasia (BPD) are at high risk for metabolic bone disease and growth retardation. In a prospective study, we compared growth and bone mineral content (BMC) during the first year of life in 16 VLBW infants with BPD and 16 VLBW control infants. The BPD and control groups were matched for gestational age (28.2 +/- 0.8 vs 28.4 +/- 1.2 weeks) and birth weight (986 +/- 158 vs 1037 +/- 147 g). Calcium, phosphorus, vitamin D, and energy intakes did not differ during the initial 60-day period of hospitalization. At 1 year of age, there were no significant differences in BMC (104.4 +/- 21.4 vs 109.7 +/- 19.2 mg/cm), weight (7440 +/- 1090 vs 7420 +/- 826 g), length (66.9 +/- 3.4 vs 67.7 +/- 3.0 cm), or head circumference (45.1 +/- 1.5 vs 44.0 +/- 1.0 cm) between BPD and control groups. In both groups bone mineralization was delayed compared to the intrauterine curve for BMC. Growth was also delayed compared to the growth curves of Babson for premature infants during the first year of life. We conclude that for our study population, factors other than the presence or absence of BPD are responsible for marked delays in bone mineralization and growth in VLBW premature infants.

Birth Weight↗
PubMed1987

Helpless in Gaza.

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Ambulatory Care Facilities↗
PubMed1986

Increased urinary excretion of inorganic sulfate in premature infants fed bovine milk protein.

We report measurements of urinary inorganic sulfate (iSO4) in 38 very low birth weight (VLBW) premature infants receiving various protein intakes in the first 2 months of life. The primary source of urinary iSO4 is the metabolism of amino acids containing sulfur (methionine, cysteine, taurine). It was hypothesized that urinary iSO4 excretion would be increased in VLBW infants fed the relatively high concentrations of protein in mother's own milk (HM), mother's own milk fortified with 0.85 gm/dl bovine whey (fortified HM), and a special formula for premature infants (Similac Special Care, 20 cal/oz), and that urinary iSO4 excretion would correlate with calcium excretion. VLBW premature infants fed HM (protein intake 3.3 gm/kg day) excreted very small amounts of urinary iSO4 compared with infants fed fortified HM (4.5 gm/kg/day protein), Similac SC (2.9 gm/kg/day protein), or Similac (2.7 gm/kg/day protein), all three of which contain bovine whey. Unlike the case in adults, there was no correlation between either total protein intake and urinary calcium excretion or urinary iSO4 excretion. There was, however, a significant correlation between methionine intake and urinary iSO4 excretion (r = 0.48). We speculate that increased urinary iSO4 excretion is indicative of an overload of sulfur-containing amino acids, namely methionine, present in bovine whey protein. The data also support the ability of premature infants to catabolize relatively large quantities of sulfur-containing amino acids after 2 weeks of age.

Animals↗
PubMed1986

Selective and differential medium for the primary isolation of members of the Proteeae.

A new differential and selective medium for the isolation of members of the Proteeae, PIM (Proteeae isolation medium) agar, was developed and evaluated. The medium relies on the ability of all members of the Proteeae (with the exception of a very few Morganella morganii strains) to produce a dark brown pigment in medium containing DL-tryptophan. An additional differential property, tyrosine degradation, was also demonstrated by the medium. Members of the Proteeae appeared as dark brown colonies with a halo of clearing of fine tyrosine crystals when cultured on PIM agar. Occasional strains of Citrobacter sp. and Pseudomonas aeruginosa may degrade tyrosine, but none has the ability to produce dark brown pigmentation on PIM agar. Quantitative recovery studies showed that the addition of 5 mg of clindamycin per liter suppressed gram-positive bacteria without inhibiting any strains of the Proteeae. The addition of 100 mg of colistin per liter made the medium highly selective for strains of the Proteeae, but approximately 10% of the strains were not isolated, thus making this formulation unsuitable for general surveys of the occurrence of members of the Proteeae. PIM agar should aid the investigation of episodes of cross infection caused by members of the Proteeae and the isolation of the new species of the Proteeae recently described.

Clindamycin↗
PubMed1986

Bone growth with low bone mineral content in very low birth weight premature infants.

We report serial measurements of bone mineral content (BMC), bone width (BW, a measure of appositional bone growth), and the ratio of BMC:BW by photon absorptiometry of the left radius through the first 10 wk of life in 38 very low birth weight premature infants (birth weight less than 1300 g, gestational age less than 32 wk). Fifteen of 38 infants developed bronchopulmonary dysplasia (BPD) and as a group they could not be distinguished from the 23 infants without BPD, despite the high association between BPD and metabolic bone disease. As BPD occurred in the smaller patients, the BPD group had a significantly lower mean birth weight and mean gestational age as compared to controls (950 +/- 125 g versus 1119 +/- 149, and 28.0 +/- 0.8 versus 29.0 +/- 1.3 wk). For both control and BPD groups, BMCs did not differ and remained relatively unchanged throughout the first 10 wk of life, lagging significantly behind the intrauterine rate as defined by measuring BMC in 175 infants of varying gestational ages during the first few days of life. BW also did not differ during this period between groups. BW did increase significantly in both groups (from 3.2 +/- 0.3 to 3.9 +/- 0.4 mm in the controls and from 3.0 +/- 0.3 to 3.8 +/- 0.4 mm in the BPD group), but remained significantly delayed compared to the intrauterine rate. In both groups, BMC remained relatively constant despite increasing BW and thus BMC/BW decreased during the first 10 wk of life (from 11.5 +/- 1.3 to 10.2 +/- 1.9 in the controls and from 11.0 +/- 1.3 to 8.6 +/- 2.2 in the BPD group).(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗
PubMed1984

Changes in fat concentration of human milk during delivery by intermittent bolus and continuous mechanical pump infusion.

The changes in fat concentration and cumulative fat losses that occur during the delivery of human milk using two different continuous infusion systems were compared with the changes in fat concentration during simulated intermittent gavage or bolus feedings. With both mechanical pumps the largest cumulative fat losses and the greatest decreases in fat concentrations occurred at the slowest infusion rates. State of homogenization of the milk generally made little difference in the changes in fat concentration using the syringe pump, whereas homogenizing the milk increased the fat concentration significantly with the roller pump. With the syringe pump the positioning of the syringe tip (horizontal or vertical) made no difference in fat concentration at an infusion rate of 1 ml/hr, whereas at 4 and 7 ml/hr the fat concentration was increased significantly by keeping the syringe tip vertical. With either mechanical pump a large fat bolus was delivered during the eighth and final hour of infusion if the milk remaining in the tubing was recovered by using air infusion at the same infusion rate. Intermittent bolus delivery of human milk resulted in no significant loss of human milk fat, no changes in fat concentration, and no terminal delivery of a large fat load. Thus intermittent bolus feedings are preferred over continuous mechanical pump infusion systems for the delivery of human milk to low-birth-weight infants.

Enteral Nutrition↗