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Biomedical subjects

J B Miller

Publications and source records attributed to J B Miller.

At least 127 records · Page 7Linked to original sources
PubMed1986

Preliminary observations on the results of combined temporary 192iridium implantation and external beam irradiation for carcinoma of the prostate.

We treated 43 patients with adenocarcinoma of the prostate confined to the pelvis with a combination of staging pelvic lymphadenectomy, temporary implantation of the prostate with 192iridium and external beam irradiation. The procedure was relatively safe with low early morbidity. However, there were significant late complications. Of these patients 29 had needle biopsy of the prostate 1 year after completion of therapy and 15 demonstrated residual tumor. Clinical stage C and poorly differentiated tumors were not well controlled.

Adenocarcinoma↗
PubMed1986

Developmental origins of skeletal muscle fibers: clonal analysis of myogenic cell lineages based on expression of fast and slow myosin heavy chains.

A clonal analysis was used to show that skeletal muscle myoblasts are committed to distinct cell lineages during development. Myoblasts taken from embryonic chicken hindlimb muscles of different ages were cultured at clonal density. The content of fast and slow classes of the myosin heavy chain isoforms in the myotubes of the resulting muscle colonies was determined immunocytochemically with specific monoclonal antibodies that served as markers for the different fiber types. The muscle colonies formed by cloning myoblasts from early hindlimbs (days 4-6 in ovo) were of three types: the most numerous type, in which all myotubes in a colony contained only the fast class of myosin heavy chain; a less numerous type, in which all myotubes in a colony contained both the fast and slow classes of myosin heavy chain isoforms; and a rare type, in which all myotubes in a colony contained only the slow class of myosin heavy chain. The muscle colonies formed by cloning myoblasts from later hindlimbs (days 10-12 in ovo) were, however, all of one type, in which every myotube in a colony contained only fast myosin heavy chain. Thus, myoblasts in the early embryo (days 4-6 in ovo) were a heterogeneous population committed to three myogenic lineages: fast, mixed fast/slow, and slow, whereas myoblasts from the later embryo (days 10-12 in ovo) were only in the fast myogenic lineage. These results suggest that muscle fiber formation is rooted in two developmental phases--an early phase in which diverse fiber types are formed from intrinsically diverse populations of myoblasts and a later phase in which fibers are formed from a single population of myoblasts.

Age Factors↗
PubMed1986

Developmental regulation of the multiple myogenic cell lineages of the avian embryo.

The developmental regulation of myoblasts committed to fast, mixed fast/slow, and slow myogenic cell lineages was determined by analyzing myotube formation in high density and clonal cultures of myoblasts isolated from chicken and quail embryos of different ages. To identify cells of different myogenic lineages, myotubes were analyzed for content of fast and slow classes of myosin heavy chain (MHC) isoforms by immunocytochemistry and immunoblotting using specific monoclonal antibodies. Myoblasts from the hindlimb bud, forelimb bud, trunk, and pectoral regions of the early chicken embryo and hindlimb bud of the early quail embryo (days 3-6 in ovo) were committed to three distinct lineages with 60-90% of the myoblasts in the fast lineage, 10-40% in the mixed fast/slow lineage, and 0-3% in the slow lineage depending on the age and species of the myoblast donor. In contrast, 99-100% of the myoblasts in the later embryos (days 9-12 in ovo) were in the fast lineage. Serial subculturing from a single myoblast demonstrated that commitment to a particular lineage was stably inherited for over 30 cell doublings. When myoblasts from embryos of the same age were cultured, the percentage of muscle colonies of the fast, fast/slow, and slow types that formed in clonal cultures was the same as the percentage of myotubes of each of these types that formed in high density cultures, indicating that intercellular contact between myoblasts of different lineages did not affect the type of myotube formed. An analysis in vivo showed that three types of primary myotubes--fast, fast/slow, and slow--were also found in the chicken thigh at day 7 in ovo and that synthesis of both the fast and slow classes of MHC isoforms was concomitant with the formation of primary myotubes. On the basis of these results, we propose that in the avian embryo, there is an early phase of muscle fiber formation in which primary myotubes with differing MHC contents are formed from myoblasts committed to three intrinsically different primary myogenic lineages independent of innervation and a later phase in which secondary myotubes are formed from myoblasts in a single, secondary myogenic lineage with maturation and maintenance of fiber diversity dependent on innervation.

Animals↗
PubMed1986

Lipoprotein-stimulated and estradiol-maintained progesterone secretion by dissociated rabbit luteal cells in vitro.

Elevated activity of 3-hydroxy-3-methyglutaryl coenzyme A reductase (HMG-CoA reductase) was observed in the rabbit ovary and corpus luteum during pregnancy. Based on this study, it was proposed that de novo cholesterol synthesis rather than the uptake of exogenous plasma cholesterol (lipoproteins) was of primary importance in providing steroid substrate for progesterone synthesis by the rabbit luteal cell. Using a perifusion system, the present study challenges this hypothesis by demonstrating that both low- and high-density lipoproteins (at protein concentrations of 100 micrograms/ml and 50 micrograms/ml, respectively) were able to acutely stimulate progesterone production by dissociated rabbit luteal cells. The increase in progesterone synthesis was due to increased cholesterol substrate and not to protein-enhanced progesterone release. The ability of luteal cells to respond to lipoproteins was dependent on both dose- and sequence of treatment, with high-density lipoprotein (HDL) being unable to stimulate progesterone production if preceded by perifusion with low-density lipoprotein (LDL) or HDL. In addition, 17 beta-estradiol appeared to regulate lipoprotein utilization by attenuating the LDL response after 1 h of perifusion. We conclude that lipoproteins may provide cholesterol substrate for progesterone biosynthesis in vitro and that 17 beta-estradiol, in addition to maintaining progesterone production by luteal cells, may also regulate lipoprotein utilization. Thus, maintenance of steady progesterone secretion in response to estradiol supercedes that of LDL-stimulated progesterone secretion by rabbit luteal cells in vitro. This study suggests an interaction between estrogen and lipoproteins that may prove physiologically important in regulating progesterone production by rabbit luteal cells in vivo.

Animals↗
PubMed1986

Estradiol suppression of luteinizing hormone (LH)/human chorionic gonadotropin receptors and LH-sensitive adenylyl cyclase without decreased adenosine 3',5'-monophosphate content in rabbit corpora lutea.

It has been observed that elevated concentrations of estradiol, the principle luteotropin in the rabbit, reduce LH-stimulated adenylyl cyclase activity in corpora lutea during midpseudopregnancy without suppressing serum and tissue progesterone concentrations. If LH modulates intraluteal cAMP levels in this species, this suggests that in the presence of exogenous estradiol, progesterone synthesis may be independent of cAMP. To test this possibility and to investigate the physiological significance of LH in regulating the rabbit corpus luteum, the concentrations of cAMP and progesterone and the activity of adenylyl cyclase were measured in luteal homogenates, the numbers of LH/hCG receptors were estimated in crude membrane preparations, and the concentrations of progesterone and estradiol were measured in serum on days 2-12 of pseudopregnancy in rabbits treated with or without estradiol. Throughout days 2-12 of pseudopregnancy, estradiol treatment increased LH-stimulated adenylyl cyclase activity on day 2, but reduced its activity after day 4 by up to 50%, reduced the number of LH/hCG receptors after day 2 by up to 50%, and had no effect on the activities of basal, epinephrine-stimulated, or NaF-stimulated adenylyl cyclase. Tissue cAMP levels were not altered by estradiol treatment, nor were serum progesterone concentrations (except for an increase on day 2). Since LH receptors and LH-stimulated adenylyl cyclase were both reduced by day 5 of pseudopregnancy without a concomitant decrease in luteal cAMP or serum progesterone concentrations, our data suggest that LH is not a physiological regulator of luteal cAMP or serum progesterone during days 4-12 of pseudopregnancy. We propose that basal adenylyl cyclase activity, which is not reduced by estradiol treatment, may play a more significant role than LH-stimulated adenylyl cyclase activity in regulating tissue cAMP levels and the progesterone synthetic capacity of the rabbit corpus luteum.

Adenylyl Cyclases↗
PubMed1985

The pattern and clinical significance of karyotypic abnormalities in patients with idiopathic and postpolycythemic myelofibrosis.

Six of eight (75%) patients with postpolycythemic myelofibrosis (PPMF) and 11 of 20 (55%) patients with idiopathic myelofibrosis (MF), seen at the University of Chicago, had abnormal karyotypes in cells of bone marrow origin. The specific chromosomal findings and their clinical significance in these patients were analyzed. A review of the literature added the findings from abnormal karyotype studies in 10 patients with PPMF and 36 patients with MF to this series. The demonstration of an increased frequency of cytogenetic abnormalities after cytotoxic therapy in polycythemia vera (PV) implies that such therapy may have a role in the development of chromosomal changes seen in treated PV and PPMF. The cytogenetic abnormalities in MF appear to be unrelated to therapy except possibly for an association with partial or complete losses of chromosome 5 or 7. Trisomy 8 is the only finding that is more common in MF than in PPMF. Other abnormalities were more common in PPMF, particularly 20q-, loss of 7 or 7q-, and trisomy 9, and to a lesser extent trisomy 1q and 5q-. Cytogenetic abnormalities do not show a pattern that can be used to distinguish between PPMF and MF, nor are they useful in the prognosis of MF or in initial studies in PPMF. PPMF does appear to have a higher tendency toward leukemic transformation than does MF, and an evolution in karyotype appears to have serious prognostic implications in PPMF in regard to this transition.

Adult↗
PubMed1985

A thermolabile variant of alpha-L-fucosidase--clinical and laboratory findings.

A family with two sibs affected clinically with the severe infantile form of fucosidosis is described. Biochemical studies revealed a relatively high residual activity (34-60% of normal) with markedly decreased thermostability. The importance of including thin layer chromatography for urinary oligosaccharides in the diagnostic workup for such patients is emphasized.

Chromatography, Thin Layer↗
PubMed1985

Slow and fast myosin heavy chain content defines three types of myotubes in early muscle cell cultures.

We prepared monoclonal antibodies specific for fast or slow classes of myosin heavy chain isoforms in the chicken and used them to probe myosin expression in cultures of myotubes derived from embryonic chicken myoblasts. Myosin heavy chain expression was assayed by gel electrophoresis and immunoblotting of extracted myosin and by immunostaining of cultures of myotubes. Myotubes that formed from embryonic day 5-6 pectoral myoblasts synthesized both a fast and a slow class of myosin heavy chain, which were electrophoretically and immunologically distinct, but only the fast class of myosin heavy chain was synthesized by myotubes that formed in cultures of embryonic day 8 or older myoblasts. Furthermore, three types of myotubes formed in cultures of embryonic day 5-6 myoblasts: one that contained only a fast myosin heavy chain, a second that contained only a slow myosin heavy chain, and a third that contained both a fast and a slow heavy chain. Myotubes that formed in cultures of embryonic day 8 or older myoblasts, however, were of a single type that synthesized only a fast class of myosin heavy chain. Regardless of whether myoblasts from embryonic day 6 pectoral muscle were cultured alone or mixed with an equal number of myoblasts from embryonic day 12 muscle, the number of myotubes that formed and contained a slow class of myosin was the same. These results demonstrate that the slow class of myosin heavy chain can be synthesized by myotubes formed in cell culture, and that three types of myotubes form in culture from pectoral muscle myoblasts that are isolated early in development, but only one type of myotube forms from older myoblasts; and they suggest that muscle fiber formation probably depends upon different populations of myoblasts that co-exist and remain distinct during myogenesis.

Animals↗
PubMed1985

Steroidogenic effect of 17 beta-estradiol on rabbit luteal cells in vitro: estrogen-induced maintenance of progesterone production.

Previous studies have established that 17 beta-estradiol is the principal luteotropic hormone in the rabbit. However, a direct effect of 17 beta-estradiol on rabbit luteal cell progesterone production has been difficult to show in vitro. The goal of this study was to develop a system in which the effect of estrogen on luteal cell progesterone production could be studied in vitro. To that end, a dissociated rabbit luteal cell preparation was developed using collagenase and the resultant isolated cells were studied using a perifusion system. Optimization of the cell digest procedure revealed that: inclusion of 2% bovine serum albumin in our optimal dissociation medium increased cell yield; and animals killed by cervical dislocation maintained more stable levels of progesterone during a 7-h perifusion compared to animals killed with barbituate-induced euthanasia (euthobarb). When dissociated luteal cells were perifused with medium, stable progesterone output (greater than 80% of initial levels) was observed for 5-6 h, after which medium progesterone concentrations declined. The inclusion of 17 beta-estradiol (10(-8) M) in the perifusion medium maintained progesterone output at control levels for up to 15 h. However, the maintenance of progesterone was not noted until after 5 h of perifusion, suggesting that the effect of estradiol may be time dependent. Thus, this investigation describes a rabbit luteal cell dissociation technique and perifusion system that may be used to examine the mechanism through which estradiol acts to maintain rabbit luteal progesterone production.

Adenylyl Cyclases↗
PubMed1985

Cyclophosphamide versus 5-fluorouracil, doxorubicin, and mitomycin C (FAM') in the treatment of hormone-resistant metastatic carcinoma of the prostate: a preliminary report of a randomized trial.

There is no evidence that combination chemotherapy is superior to single agents in the treatment of advanced, hormone-resistant carcinoma of the prostate. We are reporting the preliminary results of a randomized trial comparing cyclophosphamide (CTX) with a combination of 5-fluorouracil, doxorubicin and mitomycin C (FAM'). Thirty-one patients were randomized and 30 of them were evaluable for response. Sixteen patients were treated with CTX and 14 with FAM'. On the CTX arm, eight (50%) of the patients had stable disease (SD) and eight (50%) had progressive disease (PD). On the FAM' arm, one (7%) patient had partial response (PR), five (36%) patients had SD and eight (57%) failed to respond. The difference in response rates between the two regimens was not significant (P greater than .72). The median time to progression (MTP) of all patients treated with CTX was six weeks and the MTP of patients treated with FAM' was 16 weeks (P less than .007). This difference in MTP could be explained in part by the unequal time to reevaluation between the two regimens. The MTP of the responders on CTX however, was 13 weeks, while for FAM' it was 33 weeks (P = .014). This difference suggests that FAM' has superior activity to CTX. Pain alleviation was seen in 25% of patients treated with CTX and in 64% of those treated with FAM' (P less than .01). Toxicity was tolerable on both regimens. We conclude that CTX and FAM' have similar response rates. Patients treated with FAM' enjoyed longer MTP and greater pain alleviation than those treated with CTX.

Adenocarcinoma↗
PubMed1985

Pathologic stages IA and IIA Hodgkin's disease: results of treatment with radiotherapy alone (1968-1980).

Between Jan 1, 1968, and Dec 31, 1980, 108 previously untreated patients with Hodgkin's disease pathologic stages (PSs) IA (29 patients) and IIA (79 patients) initially received radiotherapy alone. One postoperative death (due to pulmonary embolus) (0.9%) occurred, with one serious complication (0.9%). Between 1968 and 1973, patients were randomized to receive either involved field radiation treatment (RTIF) or extended field radiation treatment (RTEF). Since 1973 all patients have received RTEF, 4,000 cGy in four to five weeks, with a median follow-up of 7.4 years. Complete remission (CR) was achieved in 102 patients (94.4%), with no significant difference according to treatment or stage. Of the complete responders, 25 patients relapsed: 5/15 RTIF and 20/87 RTEF (P = .6). Twenty-one of 25 relapsing patients achieved a second CR. Disease free survival rates at five and ten years constituted: PS IA, 78.6% for both; PS IIA, 74.8% and 73.1% (P = .6); RTEF, 76.7% for both; RTIF, 73.3% and 66.7% (P = .7). Eighteen patients have died: eight of recurrent lymphoma, two of pulmonary embolus, one each of myocardial infarction, pulmonary fibrosis, and acute nonlymphocytic leukemia (ANLL) (following salvage chemotherapy), and one of diffuse histiocytic lymphoma (DHL). Four patients died in remission of unrelated causes. Actuarial survival rates at five and ten years constituted: PS IA, 95.7% and 72.4%; PS IIA, 89.6% and 81.4% (P = .3); RTIF, 93.7% for both; RTEF, 90.7% and 71.2% (P = .2). Age, sex, number of sites, and mediastinal involvement did not influence the outcome. Acute toxicity was modest and more frequent among those receiving RTEF (P = .08). Chronic toxicity (onset more than 30 days after completion of treatment) was identified in 16 patients: 1/16 RTIF; 15/92 RTEF (P = .5). Three patients developed a second malignancy: one carcinoma of the cervix in situ; one ANLL (following salvage chemotherapy); and one DHL of the stomach. At least 75% of patients with PS IA and IIA Hodgkin's disease were cured by radiation alone, with a risk of secondary malignancy following radiation alone of 0.9%. Since the majority of relapsing patients were successfully salvaged by chemotherapy, radiation alone appears to be the initial treatment of choice in this group of patients.

Actuarial Analysis↗
PubMed1985

Cervicovaginal fistulas: management of subsequent pregnancy.

Cervicovaginal fistulas that develop after midtrimester abortion represent a significant risk to subsequent pregnancies. Since patients with this condition appear to be at increased risk for preterm labor and cervical incompetence, I recommend a cerclage procedure. The probability of complications during labor in such cases makes elective cesarean delivery the method of choice.

Adult↗
PubMed1984

Acetylcholine receptors from Torpedo californica membrane vesicles are metabolized after fusion with cultured mammalian muscle cells.

Polyethylene glycol was used to fuse Torpedo californica membrane vesicles containing acetylcholine receptors to monolayers of mammalian muscle cells in culture. Ten to 15% of the transferred Torpedo receptors had an outwardly-directed alpha-bungarotoxin binding site and were degraded by the host cells with an apparent halftime of 30-40 h. The apparent half-time of degradation of host cell AChRs in contrast, was 8-12 h. Treatment of the cells with NaCN or puromycin reduced the rate of degradation of both endogenous and Torpedo acetylcholine receptors. The remaining Torpedo receptors that were associated with the host cells were not accessible to alpha-bungarotoxin, but were in membrane vesicles that were sloughed off into the medium. These data suggest that a portion of the transferred receptors are integrated into the host cell membranes.

Animals↗
PubMed1984

Regulation of acetylcholine receptors in the mouse muscle cell line, C2.

The effects of culture age, muscle activity, and cell fusion on the metabolism of acetylcholine receptors in the mouse muscle cell line, C2, were determined. Receptor degradation followed complex kinetics and was dependent on culture age. One or two day old myotubes degraded receptors rapidly (t50 = 7-8 h) in a nearly single exponential process. Four or five day old myotubes, however, degraded receptors more slowly (t50 = 12-16 h) in a process that deviated substantially from single exponential kinetics. A similar complex pattern of receptor degradation was seen with the L6 cell line, but receptor degradation followed single exponential kinetics and was independent of culture age in primary rat myotubes and the BC3H-1 cell line. Acetylcholine receptors on C2 myotubes were immunologically similar to the extrajunctional receptors of denervated mouse muscle. Clustered receptors were degraded at approximately the same rate as the total receptor population and receptor turnover was not changed when spontaneous contractions of the C2 myotubes were inhibited. Newly synthesized receptors were more rapidly degraded than older receptors. Finally, receptors on fusion-arrested C2 myoblasts were degraded at the same rate (t50 = 16 h) regardless of culture age.

Animals↗
PubMed1984

Secondary carcinoma of the penis.

Secondary tumors of the penis are rare. The genitourinary and gastrointestinal tracts are the most common sites of origin. Immunoperoxidase tissue stains are useful in determining the primary site of secondary tumors of the penis. We report 2 such cases with primary tumors in the colon and rectum.

Adenocarcinoma↗