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Biomedical subjects

M Perry

Publications and source records attributed to M Perry.

At least 37 records · Page 2Linked to original sources

Measurement of histone mRNA transcript abundance in Xenopus oocytes by a quantitative primer extension assay.

A quantitative primer extension method was used to measure the mass of histone gene transcripts in mature oocytes of the amphibian Xenopus laevis. The procedure, using a large excess of gene-specific oligonucleotide primer and continuous incorporation of a radiolabeled deoxynucleoside triphosphate precursor, is more sensitive and quantitative than primer extension assays employing end-labeled primers. It was determined that there are stoichiometric amounts, approximately 2 X 10(8) copies, of mRNA for each of the five major histone gene classes in mature Xenopus oocytes. These observations are consistent with a model whereby transcription of these genes is coordinately regulated in a cell cycle-independent manner during amphibian oogenesis.

Animals

Two distinct Xenopus genes with homology to MyoD1 are expressed before somite formation in early embryogenesis.

The myogenic factors MyoD1 and myogenin contain a conserved region with similarity to the myc family of proto-oncogenes. To identify amphibian genes structurally and functionally related to these myogenic factors, we screened a Xenopus laevis embryo cDNA library under conditions of reduced stringency with probes corresponding to the myc-like helix-loop-helix motif of mouse MyoD1 and myogenin. Several distinct cDNAs that are highly related to each other and share extensive homology to MyoD1 were isolated. Transcripts from two of these genes, Xlmf1 and Xlmf25 (X. laevis myogenic factor), reach maximal levels of accumulation during gastrulation, remain at constant levels through early embryogenesis, and are found exclusively in skeletal muscles of adult frogs. The appearance of these transcripts early in development precedes the expression of cardiac alpha-actin, a molecular marker for mesoderm formation. A third cDNA, Xlmf11, contains an internal 351-base-pair deletion downstream of the myc homology region and encodes a truncated version of the protein encoded by Xlmf1. When expressed in mouse pluripotential stem cells, Xlmf1 activates the muscle cell differentiation program, resulting in expression of endogenous MyoD1, myogenin, and myosin heavy-chain genes and formation of multinucleated myotubes.

Amino Acid Sequence

Medication errors in neonatal and paediatric intensive-care units.

In a 4-year prospective quality assurance study, 315 iatrogenic medication errors were reported among the 2147 neonatal and paediatric intensive-care admissions, an error rate of 1 per 6.8 admissions (14.7%). The frequency of iatrogenic injury of any sort due to a medication error was 66/2147 (3.1%)--1 injury for each 33 intensive-care admissions. 33 (10.5%) errors were potentially serious, 32 (10.2%) caused mild patient injuries, and 1 patient had acute aminophylline poisoning after receiving five intravenous doses of the drug at a dosage ten times higher than prescribed, owing to a calculation error during dilution. A longitudinal monitoring system helps to identify iatrogenic complications due to medication errors and may help in implementing preventive measures.

Child

Neurophysins as tumor markers for small cell carcinoma of the lung. A cancer and Leukemia Group B evaluation.

Plasma human neurophysins (HNPs) were evaluated as tumor markers for patients with small cell carcinoma of the lung (SCCL) who were entered on limited disease and extensive disease treatment trials conducted by Cancer and Acute Leukemia Group B (CALGB). HNP values obtained before treatment showed 44% of tumors secreting vasopressin-associated HNP (VP-HNP), 14% secreting oxytocin-associated HNP (OT-HNP), and 11% producing both HNPs. There was a significantly higher incidence of HNP-secreting tumors for patients with extensive disease and two or more metastatic lesions than for patients with limited disease. There were no clear differences in response to treatment or in survival between patients with HNP-secreting tumors and those with nonsecreting tumors. Response to treatment evaluated by the change in plasma HNP, gave a 91% agreement with independently derived clinical impressions. Our data indicates that HNP evaluations provide sufficient sensitivity to forecast clinical response when it cannot be clearly assessed by conventional methods.

Antineoplastic Combined Chemotherapy Protocols

Medroxyprogesterone acetate and tamoxifen do not decrease aggressive behavior in CF-1 male mice.

Intact CF-1 male mice were given daily injections of either medroxyprogesterone acetate (MPA, an antiandrogen), tamoxifen (TAM, an antiestrogen), or the two drugs in combination and tested for aggressive behavior toward bulbectomized stimulus males. None of the treatments decreased fighting behavior over a 20-day test period and the presence of TAM led to increased aggression even in the presence of MPA. Testis weight was reduced by MPA while both compounds decreased seminal vesicle weight. The mechanisms involved in the observed effects are considered as well as the implications of the results for the clinical use of these compounds as modulators of testosterone-facilitated behaviors.

Aggression

Promoter sequences required for transcription of Xenopus laevis histone genes in injected frog oocyte nuclei.

Amphibian oogenesis is accompanied by the accumulation of histone mRNA and proteins in the absence of ongoing DNA replication. To begin an analysis of the mechanisms by which histone gene expression is regulated during frog oogenesis and embryogenesis, we used oocyte injection to examine the upstream sequences required for transcription of genes encoding each of the five histone classes. We found that sequences necessary for maximal levels of transcription are located 100 to 200 base pairs upstream of the corresponding start sites. In this region, each promoter examined contains conserved sequence elements, several of which seem to be histone gene class specific, in addition to other, more common sequence elements believed to be used by general transcription factors.

Animals

Phorbol myristate acetate-induced injury of isolated perfused rat lungs: neutrophil dependence.

The effect of leukocyte depletion on acute lung injury produced by intravenous or intratracheal phorbol myristate acetate (PMA) administration was studied in isolated perfused rat lungs. Vascular endothelial permeability was assessed by use of the capillary filtration coefficient (Kf,c). A predicted pulmonary capillary pressure (Ppc,p) was calculated from measurements of postcapillary resistances. These parameters were measured before and 90 min after the administration of PMA, either intratracheally or intravascularly. When blood elements were present both intratracheal and intravascular PMA caused an increased Kf,c [0.27 +/- 0.02 vs. 0.99 +/- 0.22 and 0.25 +/- 0.05 vs. 0.64 +/- 0.15 (SE) ml.min-1.cmH2O-1.100 g-1, respectively; P less than 0.05] and an increased Ppc,p (8.3 +/- 0.4 vs. 74.7 +/- 18.3 and 8.7 +/- 0.8 vs. 74.2 +/- 25.1 cmH2O, respectively; P less than 0.05). Removal of circulating leukocytes abolished the increased Kf,c when PMA was given intratracheally (0.35 +/- 0.06 vs. 0.23 +/- 0.07 ml.min-1.cmH2O-1.100 g-1) or intravascularly (0.39 +/- 0.07 vs. 0.33 +/- 0.07 ml.min-1.cmH2O-1.100 g-1). In the absence of neutrophils, Ppc,p slightly increased with intratracheal PMA, from 6.9 +/- 0.5 to 10.5 +/- 1.1 cmH2O (P less than 0.05), but was unchanged at 90 min with intravascular PMA. Depletion of circulating neutrophils with an antineutrophil serum failed to block the Kf,c change with intratracheal PMA (from 0.24 +/- 0.03 to 0.42 +/- 0.09 ml.min-1.cmH2O-1.100 g-1; P less than 0.05). Ppc,p also increased from 6.9 +/- 0.6 to 19.8 +/- 6.7 cmH2O (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Erroneous results with routine laboratory testing for immunoglobulins due to interference from circulating immune complexes in a case of hyperviscosity syndrome associated with autoimmune disease.

A patient with the hyperviscosity syndrome exhibited very high concentrations of intermediate to small circulating immune complexes (CIC), involving 40-50% of the IgG present, with IgG rheumatoid factor activity. We demonstrate that precipitation of CIC by polyethylene glycol in the reaction mixture caused interference with nephelometric methods for measuring IgM and IgA, and that failure of immunoglobulins to migrate, owing to molecular interactions, caused interference with radial immunodiffusion methods. Semiquantitative values for immunoglobulins were difficult to interpret on immunoelectrophoresis. As a result, IgM and IgA could only be quantitatively estimated by an end-point nephelometric approach that included a serum blank. Immunoelectrophoresis indicated that a large proportion of the immunoglobulins behaved as aggregates. Immunofixation electrophoresis did not reveal the presence of aggregates. The polyethylene glycol-IgG test provided an accurate assessment of the CIC concentration; the Raji cell and C1q-binding assays did not. Evidently, special techniques may be necessary for accurate determination of immunoglobulin concentrations when CIC concentrations are very high.

Aged

The relationship of psychological distress, extent of disease, and performance status in patients with lung cancer.

This study examined the association between two primary covariates, extent of disease (ED) and performance status rating (PSR), and the outcome of psychological distress in patients with small cell carcinoma of the lung. Patients were studied at the time of entry onto one of three Cancer and Leukemia Group B (CALGB) protocols: 7781 (N = 165) and 8083 (N = 139) for limited disease; and 7782 (N = 151) for extensive disease. Besides ED (limited versus extensive), a four-point rating of PSR was obtained. Psychological distress was measured by the standardized Profile of Mood States (POMS). Gender, age, marital status, education, PSR, ED and two relevant interaction terms (PSR X ED; gender X ED) were analyzed using multiple linear and hierarchical regressions. Of the six main variables, gender and PSR had significant association with POMS total mood disturbance, a summary score for POMS emotional subscales, and most of the individual subscales. The PSR X ED interaction provided a rationale for testing a new regression model in which PSR and ED were combined into a single index of impairment. The final index resulted in five levels of physical impairment which bear an approximately linear relationship to increasing levels of distress (Overall regression, P less than 0.001). These data suggest that PSR is an important factor in modelling POMS distress at both levels of ED, and that ED becomes an important factor with poorer performance status only.

Adult

Chemotherapy versus chemoimmunotherapy (CAF v CAFVP v CMF each +/- MER) for metastatic carcinoma of the breast: a CALGB study. Cancer and Leukemia Group B.

Three combination chemotherapy regimens each with or without the methanol-extracted residue of bacillus Calmette-Guérin (BCG) (MER) were compared for efficacy. After stratification for disease-free interval and dominant sites of disease, patients were randomized to either CMF (cyclophosphamide [CYC], 100 mg/m2 orally, days 1 through 14; methotrexate [MTX], 40 mg intravenously [IV], days 1 and 8; 5-fluorouracil [5-FU], 500 mg/m2 IV, days 1 and 8), or CAF (CYC, 100 mg/m2 orally, days 1 through 14; doxorubicin [DOX], 25 mg/m2 IV, days 1 and 8; 5-FU, 500 mg/m2 IV, days 1 and 8), or CAFVP (CAF as above plus vincristine [VCR], 1.0 mg/m2 IV, days 1 and 8; and prednisone [PRED], 40 mg/m2 orally, days 1 through 14). Nonspecific immunotherapy with MER was administered in five sites at 100 micrograms or at the lowest tenfold dilution that produced a 1-cm indurated lesion. A total of 432 patients were entered, but 37 were disqualified, leaving 395 evaluable for treatment results and toxicities. One hundred thirty-five evaluable patients were randomized to chemoimmunotherapy until October 28, 1978. One hundred twenty-six evaluable patients were randomized to chemotherapy alone in the same time period. For the entire study, a total of 260 evaluable patients were randomized to chemotherapy. Chemoimmunotherapy patients were compared with the initial 126 chemotherapy patients. Chemotherapy regimens were compared among all 260 patients. Patient characteristics were similar between regimens and between chemotherapy and chemoimmunotherapy treatment groups. For patients on chemotherapy plus MER, there was no significant differences between the regimens for response frequencies: 43%, 41%, and 32%, respectively for CMF, CAF, and CAFVP. The comparable chemotherapy alone group had 36%, 58%, and 63% response, respectively. The response rates, adjusted for chemotherapy regimen, were 52% and 38% (P = .02) for chemotherapy and chemoimmunotherapy, respectively. MER was associated with painful ulcers and fevers. Thus, MER produced toxicity without response or survival benefit and further randomization after October 28, 1978 was to chemotherapy alone. For 260 evaluable patients on chemotherapy alone, the complete (CR) and partial responses (PR) were 37%, 55%, and 58%, respectively for CMF, CAF, and CAFVP. These response rates for CAF and CAFVP were significantly better than CMF (P = .01 and P less than .01, respectively). These comparisons were consistent within subgroupings such as dominant sites of disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Antineoplastic Combined Chemotherapy Protocols

Stability of penicillins in total parenteral nutrient solution.

The stability of ticarcillin, mezlocillin, and piperacillin in total parenteral nutrient (TPN) solutions at concentrations commonly used in adults was determined. Each antibiotic was added separately to three different amino acids-dextrose TPN solutions in two concentrations: 10 and 20 mg/mL. Amino acids concentration ranged from 25 g/L to 50 g/L. Dextrose concentration ranged from 100 g/L to 350 g/L. Solutions were assayed for antibiotic concentration immediately after mixing (time 0) and at 4, 8, 24, and 48 hours by high-performance liquid chromatography. The effect of the added penicillins on the stability of amino acids and other TPN additives was not investigated. Mezlocillin and piperacillin 10 and 20 mg/mL exhibited stability in TPN solution at 24 hours. Ticarcillin was stable for 24 hours at a concentration of 10 mg/mL, but at 20 mg/mL it was unstable at all times tested. The three antibiotics demonstrated the same characteristic stability in all three TPN solutions, suggesting that the concentrations of dextrose and amino acids did not affect stability. Ticarcillin, mezlocillin, and piperacillin are stable for 24 hours in the TPN solutions studied.

Chromatography, High Pressure Liquid

Predicting the clinical course in intentional drug overdose. Implications for use of the intensive care unit.

Many patients admitted for observation to the intensive care unit after a drug overdose do not ultimately require intensive care interventions. We retrospectively analyzed data on 209 overdose cases to determine whether clinical assessment in the emergency room could identify patients at risk for complications. Patients were classified as low risk when none of the following high-risk criteria were present in the emergency room: need for intubation; seizures; unresponsiveness to verbal stimuli; arterial carbon dioxide pressure (tension) greater than or equal to 45 mm Hg; any rhythm except sinus; second- or third-degree atrioventricular block; QRS greater than or equal to 0.12 s; or systolic pressure less than 80 mm Hg. Of 151 low-risk patients, none developed a high-risk condition after admission, and none required an intensive care intervention. The use of these predictive criteria in our patient population would have eliminated over half the intensive care days without compromising quality of care.

Adult

Major transitions in histone gene expression do not occur during development in Xenopus laevis.

In light of the parallels that exist in the structure of histone genes in sea urchins and in the frog, Xenopus laevis, and in the early development of these animals, it has been thought that Xenopus histone gene expression might be subject to the type of developmental regulation observed in sea urchins. We have examined the patterns of histone mRNA accumulation in Xenopus oocytes and embryos by primer extension and S1 nuclease protection techniques. The data demonstrate that histone genes which are active in Xenopus oocytes, and which contribute to large pools of histone mRNA in the absence of DNA replication, are also transcriptionally active in late embryos and in cultured cells. These results suggest that, rather than activating distinct sets of histone genes at different developmental stages, the developing frog embryo reprograms the expression of histone genes active in nondividing oocytes so that their expression becomes coupled to DNA replication subsequently during embryogenesis.

Animals

Comparative psychological disturbance in patients with pancreatic and gastric cancer.

One hundred and seven patients with advanced pancreatic cancer and 111 patients with advanced gastric cancer, stratified for key medical and sociodemographic variables, were assessed with the Profile of Mood States before beginning combination chemotherapy in a national cancer clinical trials group. The pancreatic cancer patients had significantly higher self-ratings of depression, tension-anxiety, fatigue, confusion-bewilderment, and total mood disturbance; no difference was found in vigor or anger-hostility. These data support prior observations that patients with advanced pancreatic cancer experience significantly greater general psychological disturbance than patients with another type of advanced abdominal neoplasm.

Age Factors

Differential diagnosis between mesotheliomas and metastatic adenocarcinomas using monoclonal antibodies against gastrointestinal carcinoma antigen and stage-specific embryonic antigen.

Monoclonal antibodies made against gastrointestinal carcinoma antigen (GICA) and stage specific embryonic antigen (SSEA) were evaluated for their ability to distinguish normal mesothelial cells present in pleural and peritoneal fluids from adenocarcinoma cells in tissue and cytology specimens. The presence of GICA was documented in a high percentage of adenocarcinomas from the gastrointestinal tract (75/98) and in 52% of pulmonary (15/29) and 29% of ovarian (6/21) adenocarcinomas. GICA was found infrequently in breast carcinoma (1/18) and not in mesotheliomas (0/16). A similar pattern of GICA expression was seen in malignant effusions from adenocarcinomas (18/47) and mesotheliomas (0/6). SSEA was found in a high percentage of adenocarcinomas derived from the gastrointestinal tract (47/56) and the lung (26/29). SSEA was detected in breast carcinoma (8/15) more often than GICA. SSEA was detected rarely in mesotheliomas (1/16). Reactivities for epithelial membrane antigen, keratin, carcinoembryonic antigen, GICA and SSEA in adenocarcinoma and mesotheliomas were compared.

Adenocarcinoma