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Biomedical subjects

M Patterson

Publications and source records attributed to M Patterson.

At least 19 recordsLinked to original sources

Human embryonic zeta-globin chain expression in deletional alpha-thalassemias.

zeta-Globin chain expression in carriers of a number of deletional alpha-thalassemias is investigated by radioimmunoassay. In a few cases, zeta-globin mRNAs are also studied. zeta-Globin chains are detected in (--SEA/), (--MED/), and (--SPAN/) deletions, but not in six other deletional mutations. These results suggest that the DNA element capable of suppressing zeta-globin expression in adult erythroid cells is present within the (--SPAN/) deletion, while the DNA fragment between the 5' breakpoints of the (--SA/) and the (--SEA/) deletions may contain sequences necessary for augmenting zeta-globin expression in adult erythroid cells. Furthermore, zeta-globin chains are shown by an immunocytologic technique to be present in all circulating erythrocytes in carriers of the (--SEA/) and (--MED/) deletions. This simple immunocytologic test is highly sensitive and specific to detect adult carriers of either the (--SEA/) or (--MED/) deletions, and can be used for the detection of couples at risk of pregnancies involving fetuses with homozygous alpha-thalassemia.

Chromosome Deletion

A randomized double-blind study of neuroelectric therapy in opiate and cocaine detoxification.

Prior research on the use of transcranial neuroelectric stimulation suggested that the application of low-amperage, low-frequency alternating current via surface electrodes placed in the mastoid region could relieve the physiological signs and subjective symptoms of withdrawal and craving during opiate detoxification. These effects were reported without gradual tapering of the opiate or the addition of other medications. To test the efficacy of one particular form of neuroelectric therapy (NET), a double-blind, randomized, placebo-controlled study was conducted comparing active NET and placebo NET in the treatment of withdrawal and stabilization of 18 opiate-dependent and 25 cocaine-dependent subjects. Scores on scales for measuring substance withdrawal and craving for each abused substance, as well as the multiple dimensions of mood, were compared for degree of difference across the 10 days of treatment. There was an overall completion rate of 88%, with both cocaine and opiate groups reporting a comfortable detoxification and substantial improvement over the course of a 12-day hospitalization. There was no significant difference between the active or placebo groups, suggesting that placebo was as effective as active NET in reducing drug withdrawal or craving during cocaine and opiate detoxification. However, all placebo patients received 0.2 mA of current, which may have provided a degree of active current. Suggestions are offered for future research.

Adult

Surface antigens of male worms and microfilariae of Onchocerca gibsoni.

Living adult males and microfilariae of the cattle filarial parasite Onchocerca gibsoni were externally labelled with radioactive iodine using the iodogen and Bolton-Hunter procedures. Characterization of labelled surface proteins by sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis revealed clear cut differences in the two life cycle stages. In addition, the two radiolabelling procedures yielded some differences in the profiles of radiolabelled surface proteins for both adults and microfilariae. Immunoprecipitation analysis revealed a number of labelled antigens recognized by antibodies in human onchocerciasis serum pools, thereby demonstrating the usefulness of O. gibsoni as a model in Onchocerca volvulus vaccine studies. The reactivity of microfilarial antigens extended to antibodies from other human nematode infections, whereas male surface antigens, particularly those of low molecular weight, were Onchocerca specific. This indicates that O. gibsoni can provide a convenient source of specific diagnostic antigen.

Animals

Discrepancies between patient report, clinical assessment, and urine analysis in psychiatric patients during inpatient admission.

Self-report and clinical assessment of substance use were compared with urine analysis results in 56 male patients consecutively admitted for inpatient psychiatric treatment. All subjects received DSM-III-R Axis I diagnosis and were classified into diagnostic groups. Urine samples were tested for cocaine, marijuana, opiates, phencyclidine (PCP), amphetamines, and barbiturates. Thirty-five of the 56 patients (62%) produced urine samples that were positive for at least 1 substance of abuse. Of this group, 15 patients (27% of total sample) denied substance use during the week prior to admission. In addition, the admitting physician did not identify intoxication in 23 of the 35 patients (66%) with positive urines. The admitting physician's assessment matched the patient's answers regarding recent substance use in 79 percent of the patients. This association was especially apparent with the 26 patients who denied recent substance use, all but one of whom received a drug-negative assessment from the admitting physician.

Humans

Observation unit management of pediatric emergencies.

Observation units for children in an Emergency Department setting can serve to improve the quality of medical care provided as well as reduce overall costs; however, they must be properly organized with careful consideration for the needs of children. Policies must be written specifying who is in charge as well as who can be accepted into these units and for how long. Procedures regarding documentation and sign-out must be formulated. These units must be well staffed and fully equipped, and they should be pleasant places for the children to stay; otherwise, what might begin as assets can quickly become disorganized and potentially dangerous liabilities.

Child

The use of the MacAndrew Alcoholism Scale in detecting substance abuse and antisocial personality.

We evaluated the hypothesis that characterological factors, particularly antisocial personality, influence scores on the MacAndrew Alcoholism Scale (MAC). Using the Washington University research criteria to establish diagnoses, the following subgroups were defined: subjects who received no psychiatric diagnoses; subjects who received diagnoses other than alcoholism, drug dependence, or antisocial personality; and subjects who received a diagnosis of alcoholism, drug dependence, and/or antisocial personality, alone or in combination with other psychiatric diagnoses. The highest MAC scores were obtained by subjects diagnosed as having antisocial personality without alcoholism or drug dependence and subjects diagnosed with antisocial personality, drug dependence, and alcoholism. Alcoholics without antisocial personality or drug dependence, and subjects with other psychiatric diagnoses scored lowest. Although higher MAC scores were obtained by males, MAC scores greater than 24 correctly classified the greatest number of males and females as alcoholic, drug dependent and/or antisocial. These findings are interpreted as consistent with MacAndrew's reinterpretation of the scale as assessing a dimension of personality, rather than solely a tendency to addiction.

Adult

How cells recognize damaged DNA: clues from xeroderma pigmentosum and yeast.

Xeroderma pigmentosum (XP) is characterized by the defective excision repair of DNA damaged by many agents, including ultraviolet radiation (UV) and cisplatin. We have identified a factor in human cells that recognizes multiple forms of DNA damage and is absent in XP complementation group E. Denoted XPE binding factor, it is expressed at five-fold higher levels in tumor cell lines resistant to the antitumor drug cisplatin. Finally, although it does not have photoreactivating activity, XPE binding factor shares multiple binding characteristics with yeast photolyase, suggesting that it is the human homolog of photolyase.

Cells, Cultured

The perilymphatic fistula: the end of an enigma?

While the existence of a perilymphatic fistula may be suggested on the basis of a patient's history and physical findings, at present the diagnosis can only be established by the identification of the actual fistula at the time of tympanotomy. In some cases, repeated reaccumulation of clear colorless fluid within the middle ear is interpreted as representing perilymph and has been considered to indicate the presence of a fistula that cannot be visualized. This subjective type of observation is made by the operating surgeon and is consequently subject to bias. At the present time there is no objective method, such as histopathology, to confirm the diagnosis of a perilymphatic fistula in this type of situation. As a result, there is some variation and controversy in the otology literature as to what surgical findings at tympanotomy should be considered as "proof" of a perilymphatic fistula. In this paper we will propose a new method for confirmation of the diagnosis of perilymphatic fistulas based on a unique biochemical property of perilymph.

Ear Diseases

Adenomatous tumors of the middle ear and mastoid.

Adenomatous tumors of the middle ear and mastoid have been called adenoma or adenocarcinoma. The clinical and pathologic distinction between the two has been difficult. The resultant pathologic ambiguity makes it difficult to decide whether conservative or radical management is appropriate. The Otologic Medical Group's (OMG) experience with glandular tumors of the middle ear and mastoid over the past 27 years was reviewed. Thirteen cases were found and analyzed with respect to signs and symptoms at presentation. Extensive histopathologic review with light and electron microscopy was performed on tumor specimens. Two distinctive histopathologic and clinical patterns were identified. The mixed type of tumor was always confined to the middle ear and mastoid, was commonly misdiagnosed as chronic otitis media, and rarely demonstrated otic capsule or facial nerve involvement. The papillary pattern always had extension to the petrous apex and frequently involved the middle and/or posterior cranial fossa. Papillary tumors were more frequent in females and usually involved the facial nerve. On the basis of the findings in this review as well as information from the literature, we have come to the following conclusions: 1. The correct general pathologic heading be Adenomatous Tumors of the Middle ear and Mastoid with each tumor then being subclassified into Mixed or Papillary tumor and adenocarcinoma when warranted by histology. 2. There is a high rate of local recurrence. 3. Long-term follow-up (at least 10 years) for all adenomatous tumors is necessary. 4. Primary surgical treatment is required.

Adenocarcinoma

Phase II study of combination 4'-epidoxorubicin and mitomycin C in recurrent epithelial ovarian cancer.

Thirty-three evaluable patients who had epithelial ovarian cancer that had not responded to treatment were entered into a phase II study of combination epirubicin and mitomycin C. Epirubicin (65 mg/m2) and mitomycin C (4 mg/m2) were administered separately, each as an i.v. bolus every 4 weeks. Ten patients (30%) had a complete or partial responses. The median duration of response was 20 weeks (range, 9-53). The regimen was well tolerated. Myelotoxicity occurred in four patients requiring hospitalization for septicaemia. Eleven patients had a blood transfusion. Alopecia was common, and nausea and vomiting, though frequent, usually mild. Cardiological toxicity was observed in one patient only. She developed congestive cardiac failure after an acute myocardial infarction. This regimen is active in advanced ovarian cancer that has not responded to prior treatment and warrants further study combination with other active drugs as a first-line regimen for ovarian cancer.

Adult

Transient expression of simple epithelial keratins by mesenchymal cells of regenerating newt limb.

Structural proteins of the intermediate filament family are an early indicator of differentiation before organogenesis becomes apparent. Keratin intermediate filaments are characteristically expressed only by epithelial and not by mesenchymal cells. Here we show, using monoclonal antibodies, a transient expression of the keratin pair 8 and 18 in a population of mesenchymal cells in the regenerating newt limb, specifically in the undifferentiated progenitor cells (blastemal cells) which give rise to the new tissues. These keratins are also expressed in cultured limb cells that can differentiate into muscle. In contrast no reactivity with anti-keratin 8 and 18 antibodies was observed in the newt limb bud at an early stage of development, indicating a molecular difference between the developing and regenerating limb. The molecular weights of the newt proteins detected by these antibodies are very similar to those of human keratins 8 and 18, further supporting the immunocytochemical evidence that the newt homologs of these keratins are expressed in blastemal cells. This is the first demonstration of keratin expression in mesenchymal progenitor cells in an adult animal.

Animals

Evidence that xeroderma pigmentosum cells from complementation group E are deficient in a homolog of yeast photolyase.

Xeroderma pigmentosum (XP) patients are deficient in the excision repair of damaged DNA. Recognition of the DNA lesion appears to involve a nuclear factor that is defective in complementation group E (XPE binding factor). We have now identified a factor in the yeast Saccharomyces cerevisiae that shares many properties with XPE binding factor, including cellular location, abundance, magnesium dependence, and relative affinities for multiple forms of damaged DNA. Yeast binding activity is dependent on photolyase, which catalyzes the photoreactivation of pyrimidine dimers. These results suggest that yeast photolyase may also function as an auxiliary protein in excision repair. Furthermore, XPE binding factor appears to be the human homolog of yeast photolyase.

Amino Acid Sequence

The effectiveness of two sonic and two ultrasonic scaler tips in furcations.

This study compared the effectiveness of two sonic and two ultrasonic scaler tips on artificial calculus removal from the furcations of mandibular first and second molars. Twenty-four extracted mandibular molars were cleaned and randomly assigned to one of four treatment groups. Teeth were split buccal lingually, artificial calculus was placed in the furcation areas, and the teeth were photographed with a stereo camera. Teeth were reconnected with bonding material and mounted in a typodont with simulated gingiva and attached to a dental chair. Teeth were instrumented with either a Cavitron TFI10 tip, Cavitron EWPP tip, Titan-S Universal tip, or Titan-S Sickle tip by a licensed dental hygienist until each tooth was judged calculus free to the touch with a CH3 explorer. Time for each instrumentation period was recorded. Following instrumentation, the teeth were again split and photographed. Stereophotogrammetry was used to produce tracings of the teeth with initial calculus and remaining calculus. Pre-instrumentation and post-instrumentation amounts of calculus on the surface area were computed using the Bioquant system. A two factor analysis of variance was conducted followed with a Newman-Keuls Multiple Comparison Technique to test for within and between differences. Significant differences (P less than or equal to 0.01) were found between pre- and post-amounts of calculus for all tips. No significant differences (P less than or equal to 0.05) were found between the four instrument tips with respect to percentage of furcation surface with calculus remaining. No differences were found between tips with regard to the time required to clean the test surfaces.

Dental Calculus

Human embryonic zeta-globin chains in fetal and newborn blood.

A sensitive and specific radioimmunoassay (RIA) for human embryonic zeta-globin chains was used to study normal fetal blood and newborn cord blood as well as cord blood from newborns with alpha-thalassemias. From 17 weeks until 37 weeks of gestation, zeta-globin chains were present in almost all fetal and cord blood samples (0.27% +/- 0.15% in samples of weeks 17 through 30; 0.14% +/- 0.11% in samples of weeks 31 through 37). zeta-Globin chains were present in greater than 80% of cord blood hemolysates from normal, full-term newborns (0.15% +/- 0.11%) as well as from 16 near-term newborns of diabetic mothers (0.13% +/- 0.13%). zeta-Globin chains were not detected in normal infants aged 3 months to 2 years. In cord blood hemolysates from alpha-thalassemic newborns, the levels of zeta-globin chain content varied from very high to undetectable levels. Gene mapping of the zeta-alpha-globin gene cluster was performed in 12 newborns in whom cord blood zeta-globin chains had been determined. Newborns who were carriers of alpha-thalassemia-1 due to the (--SEA/) deletion had very high levels of zeta-globin chains (greater than 1.5%).

Aging