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Biomedical subjects

J B Miller

Publications and source records attributed to J B Miller.

At least 109 records · Page 6Linked to original sources
PubMed1989

Pyocele of scrotum: consequence of spontaneous rupture of testicular abscess.

We report 2 cases of spontaneous rupture of the testis secondary to suppurative epididymo-orchitis. Both cases presented with pyoceles and were treated conservatively by scrotal incision and drainage of the pyoceles. This prolonged hospital stay and increased morbidity, since both patients ultimately required orchiectomy. We believe that a pyocele is an indication for prompt surgical exploration, and if the testis is ruptured, an orchiectomy should be done.

Abscess↗
PubMed1989

Thoracic bioimpedance and Doppler cardiac output measurement: learning curve and interobserver reproducibility.

Nine previously untrained health professionals learned to measure cardiac output (Qt) by suprasternal continuous-wave Doppler ultrasound (QtDopp) and by thoracic bioimpedance (Qtbi). Each received standardized written, videotaped, and individual instruction. First the novice, then the reference examiner, measured QtDopp or Qtbi in triplicate in an adult male subject. The reference examiner was blind to the novice measurements and the novice was not informed of the reference measurements. Each novice repeatedly measured QtDopp or Qtbi in different subjects until the mean novice QtDopp or Qtbi was within 10% of the corresponding mean reference measurement in three of four consecutive subjects. The novice observers required an average of 12.9 +/- 3.5 trials to learn to measure QtDopp, and an average of 8.4 +/- 4.5 trials to learn to measure Qtbi. The likelihood of novice agreement with the reference improved with experience. The same degree of intraobserver variability as reported for Qt measured by thermodilution (coefficient of variance less than or equal to 10%) was achieved with Qtbi in 150 (99%) of 152 triplicate measurements and QtDopp in 216 (97%) of 222 triplicate measurements. More importantly, interobserver agreement (within 10%) was achieved with both Qtbi and QtDopp. Reproducible noninvasive Qt measurement will allow these techniques to be used to monitor trend changes in Qt.

Cardiac Output↗
PubMed1989

Volvulus of the gallbladder. Report of two cases and review of the literature.

Torsion or volvulus of the gallbladder is a rare cause of acute cholecystitis. Although it has been reported in all age groups, it is most commonly seen in the elderly. With our increasingly aged population, it behooves the clinician to keep this entity in mind when treating the older patient with abdominal pain. We present two cases of torsion of the gallbladder and review the clinical and pathological aspects of this disease.

Acute Disease↗
PubMed1989

Protein phosphorylation in the corpus luteum.

Soluble luteal extracts were incubated with putative second messengers or regulators of protein kinases in the presence of [gamma-32P]ATP, and proteins were separated by SDS-PAGE. There was a novel phosphorylation of a protein of Mr 80,000 which was stimulated by phospholipid and 1,2-diacylglycerol but, unlike classical C-kinase phosphorylating activity, was increased by EGTA and reduced by Ca2+. This phospholipid/diolein-stimulated phosphorylation of a Mr 80,000 protein was detectable in rat and pig luteal extracts and was enhanced 2-fold in rabbit CL by administration of oestradiol-17 beta in vivo. These results suggest that the luteotrophic functions of oestradiol in rabbit CL are mediated in part by regulating either the kinase and/or the Mr 80,000 substrate.

Animals↗
PubMed1988

Developmental patterns of expression and coexpression of myosin heavy chains in atria and ventricles of the avian heart.

Monoclonal antibodies (mAbs), electrophoresis, immunoblotting, and immunohistochemistry were used to determine the molecular properties of cardiac myosin heavy chain (MHC) isoforms and the regions of the developing chicken heart in which they were expressed. Adult atria expressed three electrophoretically distinct MHCs that reacted specifically with mAbs F18, F59, or S58. During embryonic Days 2-4, when the atrial and ventricular chambers are forming, MHCs that reacted with mAbs F18, F59, or S58 were expressed in both the atria and ventricles. The atria continued to express MHCs that reacted with mAbs F18, F59, or S58 at all stages of development and in the adult. In the ventricles, expression of the MHCs reacting with these mAbs was found to be developmentally regulated. By embryonic Day 16, MHC(s) reacting with mAb F18 had disappeared from the developing ventricles, whereas MHCs reacting with S58 and F59 continued to be expressed throughout the ventricles. As development continued, MHC(s) reacting with S58 in the ventricle became restricted to expression in only the ventricular conducting system. MHC(s) reacting with F59 were expressed in both the ventricular myocytes and the ventricular conducting system throughout development and in the adult. Thus, in contrast to the embryonic chicken heart where at least three MHC isoforms were expressed in both the atria and ventricles, we found in the adult chicken heart that-at a minimum-three MHC isoforms were expressed in the atria, two MHC isoforms were expressed in the ventricular conducting system, and one MHC isoform in the ventricular myocardium. MHC isoform expression in the developing avian heart appears to be more complex than previously recognized.

Animals↗
PubMed1988

Synthesis and release of estrogen- and progesterone-dependent proteins by the baboon (Papio anubis) uterine endometrium.

This study was undertaken to determine the regulation of stage-specific endometrial proteins of the baboon uterus by estradiol (E2) and progesterone (P). Ovariectomized females were either untreated or treated with E2 for 7 or 14 days, or primed with E2 for 14 days, and then treated with E2 plus P or P alone for 7 or 14 days. Steroids were administered via Silastic capsules and, as determined by radioimmunoassay, physiological levels were present in the peripheral serum of each treatment group. Endometrial tissue obtained after steroid treatment was incubated in the presence of [35S]methionine for 24 h at 37 degrees C, and the culture medium was analyzed by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) followed by fluorography. Steroid treatment resulted in a doubling of the synthesis and release of labeled macromolecules into culture medium compared to the levels observed in long-term ovariectomized animals, together with the appearance of specific proteins whose synthesis required either E2 or E2 +/- P. A single protein (Mr 33,000; pI 7.6) was only observed after E2 treatment, and a family of high molecular weight basic proteins (Mr greater than 200,000) and a group of acidic proteins (Mr 130,000) required both E2 and P. In the absence of E2, P maintained the synthesis and release of three basic proteins (Mr 88,000, 66,000, and 40,000) as well as the other proteins observed in the ovariectomized animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Indirect regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase by oestradiol in the rabbit corpus luteum.

Rabbits were given 50 i.u. hCG, i.v., to initiate ovulation and pseudopregnancy (Day 0) and were treated, s.c., with or without a 1-cm Silastic oestradiol implant. Serum progesterone concentrations were measured at 4-day intervals and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity was estimated by the conversion of HMG to mevalonate in microsomes from corpora lutea removed on Days 4, 8, 12, 16 and 20 of pseudopregnancy (4 rabbits/day). Total HMG-CoA reductase activity was significantly (P less than 0.05) higher in control rabbits on Days 8 and 12 (5.29 +/- 0.63 and 5.5 +/- 0.28 nmol/min/mg protein, respectively) compared to oestradiol-treated rabbits (2.57 +/- 0.25 and 4.03 +/- 0.23 nmol/min/mg protein, respectively). On Days 16 and 20, total HMG-CoA reductase activity was not different in control and oestradiol-treated animals. There was no difference in the levels of the active fraction of HMG-CoA reductase, which represented less than 20% of the total enzyme activity, in control and oestradiol-treated rabbits (less than 780 pmol/min/mg protein, Day 12). These results indicate that oestradiol does not alter the active form, but can reduce the total activity of HMG-CoA reductase in the rabbit corpus luteum without a decline in serum progesterone. Therefore, neither total nor active forms of HMG-CoA reductase are directly related to progesterone secretion. This suggests that other sources of cholesterol may contribute to progesterone production in the rabbit.

Animals↗
PubMed1987

Immunological comparison of biotinidase in serum from normal and biotinidase-deficient individuals.

An antiserum specific to enzymatically active human serum biotinidase was prepared. Using this antiserum, two immunologically cross-reacting protein fractions, only one of which corresponds to the active enzyme, were observed in sera from individuals with normal biotinidase activity. Neither of these protein fractions was detected in sera from 18 individuals with biotinidase deficiency from 15 families.

Amidohydrolases↗
PubMed1987

Cell diversification within the myogenic lineage: in vitro generation of two types of myoblasts from a single myogenic progenitor cell.

We show that a single myogenic progenitor cell in vitro generates two types of myoblasts committed to two distinct myogenic cell lineages. Using fast and slow myosin heavy chain isoform content to define myotube type, we found that myogenic cells from fetal quail (day 10 in ovo) formed two types of myotubes in vitro: fast and mixed fast/slow. Clonal analysis showed that these two types of myotubes were formed from two types of myoblasts committed to distinct fast and fast/slow lineages. Serial subcloning demonstrated that the initial myoblast progeny of an individual myogenic progenitor cell were in the fast lineage, whereas later progeny were in the fast/slow lineage. Fast and slow myosin expression within particular myotubes reflects the genetic processes underlying myoblast commitment to diverse myogenic lineages.

Animals↗
PubMed1987

Evidence for multiple uterine modulators of rabbit luteal function: the effect of hysterectomy during pseudopregnancy in the estrogen-treated rabbit.

Previous studies show that hysterectomy on Day 1 of pseudopregnancy prolongs serum progesterone secretion in estrogen-treated pseudopregnant rabbits. These studies were undertaken to determine the day of pseudopregnancy when uterine factors are released to alter luteal function. When hysterectomies were performed on either Day 5, 8, 10, or 13 of pseudopregnancy, serum progesterone concentrations were greater than 10 ng/ml between Days 18 and 27 of pseudopregnancy compared to levels of approximately 4 ng/ml in sham-hysterectomized rabbits on these same days. In contrast, serum progesterone levels were not elevated when hysterectomies were performed on Day 11 of pseudopregnancy and were only partially maintained when hysterectomies were performed on Day 12 of pseudopregnancy. Twice daily injections of prolactin (1.5 mg, s.c.) between Days 1 and 33 of pseudopregnancy were unable to mimic the effect of estradiol in the hysterectomized rabbit. Twice daily injections of indomethacin (8 mg/kg, s.c.) between Days 6 and 23 of pseudopregnancy lowered uterine and luteal prostaglandin F2 alpha levels approximately 10-fold on Day 24 of pseudopregnancy but did not maintain progesterone secretion. Serum cholesterol levels were not altered by hysterectomy on any day and were thus not related to the maintenance of progesterone production. These results suggest that the uterus produces both inhibitory and stimulatory factors that effect luteal progesterone secretion. First, an inhibitor is released between Days 10 and 11 of pseudopregnancy in estrogen-treated rabbits that prevents the rabbit corpus luteum from responding to estradiol.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Evidence for the preferential utilization of esterified cholesterol in progesterone production by rabbit corpora lutea.

Our previous studies show that lipoproteins stimulate progesterone secretion by rabbit luteal cells in vitro and that estradiol modifies this effect. This study examines the relationship between estradiol and serum lipoproteins for progesterone production by rabbit corpora lutea in vivo. Using morphometric analysis, we determined that estrogen treatment of hysterectomized pseudopregnant (E-hyst) rabbits increased luteal lipid volume by mid-pseudopregnancy without altering serum progesterone levels. Treatment of E-hyst rabbits with 4-amino-3,4,pyrazolo pyrimidine (APP) during early to mid-pseudopregnancy reduced serum cholesterol levels without decreasing serum progesterone concentrations. However, 3-hydroxy-3 methyl glutaryl-CoA reductase activity was increased. Thus, in the presence of exogenous estrogen, serum cholesterol is esterified and stored rather than converted directly into progesterone. APP-treatment of E-hyst rabbits during late-pseudopregnancy, when estrogen receptor levels are low, increased serum progesterone levels and reduced intracellular lipid content. Thus, stored lipid is the primary source of cholesterol for progesterone synthesis. In addition, estrogen, via estrogen receptor, is important in maintaining steady progesterone output despite fluctuations in serum lipoprotein levels. A working model for cholesterol utilization by rabbit luteal cells is presented, which suggests that stored cholesterol esters, derived from both endogenous and exogenous sources, is the key source or cholesterol for progesterone production. Furthermore, we propose that estradiol regulates the uptake and storage of cholesterol and its rate of metabolism into progesterone.

Adenine↗
PubMed1987

The effect of human chorionic gonadotropin, dibutyryl cyclic adenosine 3',5'-monophosphate, prostaglandins, and 25-hydroxycholesterol on acute progesterone secretion by dissociated rabbit luteal cells in vitro: evidence for independent effect of human chorionic gonadotropins and lipoproteins.

Although estradiol is the established luteotropic hormone in the rabbit, the corpus luteum also contains a luteinizing hormone (LH)-activated adenylate cyclase system and cyclic adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase, which suggests that LH and cAMP may play a physiological role in regulating luteal progesterone production. The present study examined whether human chorionic gonadotropin (hCG) and cAMP derivatives stimulate progesterone production by dispersed rabbit luteal cells in static and perifusion incubations. Results of this study show that progesterone production by rabbit luteal cells is significantly stimulated (p less than 0.05) by hCG concentrations at or greater than 0.1 IU/ml or by dibutyryl cAMP concentrations at or greater than 5 mM. Both agents produce maximal stimulations of approximately 4-fold. However, neither prostaglandin E2 or F2 alpha at concentrations of 0.1-3.0 micrograms/ml altered progesterone secretion. When luteal cells were incubated with maximal concentrations of hCG and lipoproteins together, the resultant progesterone secretion was additive. This suggests that the effects of hCG and lipoprotein are independent. Both responses could be blocked completely by cycloheximide (10(-4) M), and thus appear to be dependent on protein synthesis. The cholesterol derivative 25-hydroxycholesterol (20 micrograms/ml) partially overcame the steroidogenic block by cycloheximide, suggesting that transport of cholesterol, regardless of its origin, into mitochondria was an essential protein-mediated event in these cells. Inhibition of the side-chain-cleavage enzyme by aminoglutethamide blocked progesterone production by rabbit luteal cells in vitro. Although estradiol may dominate in the regulation of luteal progesterone production physiologically, this study clearly demonstrates that potential mechanisms do exist in the rabbit corpus luteum for cAMP-mediated stimulation of progesterone production in the rabbit.

Animals↗
PubMed1987

Molybdenum-sensitive transcriptional regulation of the chlD locus of Escherichia coli.

The chlD gene in Escherichia coli is required for the incorporation and utilization of molybdenum when the cells are grown with low concentrations of molybdate. We constructed chlD-lac operon fusions and measured expression of the fusion, Mo cofactor, and nitrate reductase activities under a variety of growth conditions. The chlD-lac fusion was highly expressed when cells were grown with less than 10 nm molybdate. Increasing concentrations of molybdate caused loss of activity, with less than 5% of the activity remaining at 500 nM molybdate; when tungstate replaced molybdate, it had an identical affect on chlD expression. Expression of chlD-lac was increased in cells grown with nitrate. Strains with chlD-lac plus an additional mutation in a chl or nar gene were constructed to test whether the regulation of chlD-lac required the concerted action of gene products involved with Mo cofactor or nitrate reductase synthesis. Mutations in narL prevented the increase in activity in response to nitrate; mutations in chlB, narC, or narI resulted in partial constitutive expression of the chlD-lac fusion: the fusion was regulated by molybdate, but it no longer required the presence of nitrate for maximal activity. Mutations in chlA, chlE, or chlG which affect Mo cofactor metabolism, did not affect the expression of chlD-lac.

Coenzymes↗
PubMed1987

Childhood sexual and physical abuse as factors in adult psychiatric illness.

Using objective measures, the authors found a high rate of childhood sexual and physical abuse in a sample of 66 female psychiatric inpatients. Childhood abuse experiences were correlated with severity of adult psychiatric symptoms. The authors explore the usefulness of adult psychological symptoms, diagnoses, and prescribed medications as factors in the identification of patients who have histories of early sexual and physical abuse.

Adolescent↗
PubMed1987

Stimulation with LH of progesterone production by rabbit corpora lutea in vitro.

Quartered CL from 7-day pseudopregnant rabbits were incubated at 37 degrees C for 0-180 min in the presence of BSA, LH or adrenaline in Krebs-Ringer-bicarbonate buffer. Total progesterone at each time point was quantified in homogenates of tissue plus incubation media and expressed relative to CL protein. Progesterone increased linearly with time during the first 30 min of incubation in the presence of BSA. LH and adrenaline markedly accelerated progesterone accumulations relative to the BSA control. At 10 min, progesterone accumulation in the presence of LH and adrenaline were 2.4 and 5.9 times that in the absence of stimulators, respectively. Both hormones caused concentration-dependent increases in progesterone and the apparent ED50 was 0.75 microgram/ml for LH and adrenaline. The CL obtained from ovaries of 7-day pseudopregnant rabbits are therefore capable of an acute steroidogenic synthetic response to LH as well as adrenaline.

Animals↗
PubMed1987

Quantitative analysis of oestrogen induced morphological changes in the rabbit corpus luteum.

Although oestradiol is luteotropic in the rabbit, the mechanism through which oestradiol maintains the corpus luteum is unknown. To determine if ultrastructural changes in the rabbit corpus luteum accompany oestradiol treatment, corpora lutea were removed on day 10 of pseudopregnancy from hysterectomized rabbits treated with oestradiol implants and prepared for electron microscopy. Morphometric analysis was performed on luteal cells in each group (seven animals/group, four micrographs/animal) and organelle profile volumes, estimated by point-counting techniques, were expressed as a percentage of the cell volume. Morphometric analysis revealed no significant differences in nuclear, mitochondrial, lysosomal, Golgi or endoplasmic reticular volumes between control and oestradiol-treated animals. In contrast, lipid droplet volume was significantly elevated (p less than 0.001) in oestradiol-treated animals. This data suggests that an important function of oestradiol in the rabbit corpus luteum is to regulate the uptake and storage of cholesterol presumably for progesterone production.

Animals↗
PubMed1986

Maroteaux-Lamy syndrome in a large consanguineous kindred: biochemical and immunological studies.

We describe a large consanguineous German-Acadian ("Cajun") family from a rural area in Louisiana in which 11 persons in two generations had the Maroteaux-Lamy syndrome. The mutant arylsulfatase B enzyme in this family was similar to the mutant enzyme in previously studied families in its cross-reactivity with specific antibodies to the enzyme, but it differed in both its electrophoretic mobility and its residual enzymatic activity. These findings indicate that a different mutational event leading to Maroteaux-Lamy syndrome occurred in this family.

Child↗