Bus training for developmentally disabled adults

The effectiveness of a program combining classroom and community training in the teaching of bus-riding skills to developmentally disabled adults. These skills were taught sequentially using questions about a slide presentation, role playing, and performance in the natural environment. The experimental design was based upon the work of Neef, Iwata, and Page (1978). Test trials were conducted after each phase of training. Results showed that all subjects learned the necessary bus-riding skills and maintained their performance throughout the follow-up period of at least 1 year. The combination training method proved to be efficient and cost effective.

Emotional support providers and psychological distress among Anglo- and Mexican Americans

Accumulating evidence from studies investigating the role naturally-occurring emotional support networks play in remediating psychological distress strongly suggests that such networks buffer personal distress and lessen the need for formal mental health care. Research findings also suggest that reliance on emotional support networks varies across ethnic groups. The present study compared emotional support network characteristics of Anglo-Americans to those of Mexican Americans, in addition to examining the relationship between the reliance on specific support providers and psychopathological symptoms for Anglo- and Mexican Americans. Randomly selected adult Anglo- and Mexican Americans (n = 515) living in one of three suburban communities in Southern California provided responses to a standardized measure of psychological impairment and named those persons on whom they depended in time of personal problems. Both Anglo- and English speaking Mexican American (ES MA) respondents reported significantly larger networks and more cumulative contact and reciprocity with network members than did Spanish-speaking Mexican Americans (SS MA) respondents. Anglos and ES MAs named significantly more friends and neighbors as emotional support providers than did SS MAs. SS MAs, on the other hand, more often depended on extended kin and spouses than did the other two subgroups. Professional caregivers accounted for a very small proportion of responses across the subgroups. The number of friends and neighbors as support providers was significantly and positively correlated with problems of social relations in only the SS MA subgroup. Implications of results for community mental health direct and indirect service components are discussed.

The psychiatrically severe drug abuse patient: methadone maintenance or therapeutic community?

The present research was conducted to examine the effects of pretreatment psychiatric status and treatment duration on improvement following drug abuse rehabilitation. Percent improvement from admission to 6-month follow-up was measured on three criteria: drug use, employment, and criminality. Analyses of the total samples in both the Therapeutic Community (TC) and Methadone Maintenance (MM) programs indicated some quantitative differences between the two modalities but all measures showed a strong and positive relation between treatment duration and percent improvement. When patients in the two program samples were divided, on the basis of admission psychiatric status, into LOW, MID, and HIGH severity groups, different findings emerged. LOW severity patients in both programs showed the greatest absolute levels of improvement in most measures, more improvement at shorter treatment durations, and less additional improvement at longer treatment durations. MID severity patients in both programs showed the most dramatic effects of treatment duration, with generally large improvements in all criteria at greater treatment lengths. Qualitatively different results were seen between the treatment programs for the HIGH severity patients. HIGH severity MM patients showed low absolute levels of improvement but longer treatment durations were associated with modest improvements. HIGH severity TC patients also showed low absolute levels of improvement but unlike any other group, greater lengths of treatment were associated with negative change (worsened status) across all measures. The authors discuss these results with regard to the general efficacy of drug-dependence treatment and the specific issue of the psychiatrically impaired drug abusers.

The structure of recA protein-DNA filaments. 2 recA protein monomers unwind 17 base pairs of DNA by 11.5 degrees/base pair in the presence of adenosine 5'-O-(3-thiotriphosphate)

recA protein binds to duplex DNA in the presence of Mg2+ and adenosine 5'-O-(3-thiotriphosphate) forming a stiff nucleoprotein filament with a distinct axial repeat which contains 17 +/- 1 base pairs and spans 8-9 nm along the fiber (Di Capua, E., Engel, A., Stasiak, A., and Koller, Th. (1982) J. Mol. Biol. 157, 87-103; Dunn, K., Chrysogelos, S., and Griffith, J. (1982) Cell 28, 757-765). Measurement of the protein:DNA ratio in these filaments utilizing double label analysis and isopycnic density banding shows that there are 2 recA monomers for every 17 base pairs. The DNA is also partially unwound in this filament. Utilizing the recA-induced relaxation of naturally supertwisted SV40 DNA, we show that the DNA is unwound by 11.5 +/- 1.5 degrees/base pair which corresponds to 180-200 degrees for each repeat unit along the filament length.

Mapping restriction sites on large DNAs by electron microscopy

We have developed a novel technique to map restriction sites on large duplex DNAs by electron microscopy. In this method, the sample DNA is first cut with a restriction enzyme. The resulting fragments are briefly digested with Escherichia coli exonuclease III, and treated with wheat germ RNA polymerase II to fill-in with RNA the resulting gaps. These small RNAs, complementary to sequences immediately adjacent to either side of the restriction site, are isolated from the DNA template and R-looped to the full-length DNA. When this material is prepared by the formamide-cytochrome spreading technique, small bubbles are visible wherever there is a restriction site on the DNA. Improved methods of mapping are outlined.

A note on maritally-disrupted men's reports of child support in the June 1980 Current Population Survey

Data from the June 1980 Current Population Survey on fathers' reported provision of financial support to children from previous marriages living elsewhere is compared to previously published tabulations from the April 1979 CPS of women's receipt of child support payments. The comparison indicates that the number of men with children from previous marriages living elsewhere is substantially underreported in the June 1980 CPS. Because of the apparent underreporting, the data on the provision of financial support should be interpreted with caution.

Coat protein conformation in M13 filaments, I-forms and spheroids

Circular dichroism studies of the filamentous coliphage M13 were carried out to determine conformational changes in the major capsid protein (the B protein) that occur during contraction of the filaments to I-forms and spheroids. The alpha-helicity of the B protein is somewhat lower in the I-forms than in filaments and much lower in spheroids. This conformational change may explain the increased detergent and lipid solubility of both I forms and spheroids relative to filaments.

A comparison of bupropion, dextroamphetamine, and placebo in mixed-substance abusers

The subjective, behavioral, and physiological effects of bupropion, a nontricyclic antidepressant, were compared with those of dextroamphetamine and placebo in a randomized double-blind crossover study. The volunteers who participated were multiple-drug abusers. Six acute drug treatments, three doses of bupropion (100, 200, 400 mg), two doses of dextroamphetamine (15, 30 mg), and placebo were administered orally at intervals of not less than 72 h. Results indicated that the subjective effects of amphetamine as measured by the Addiction Research Center Inventory (ARCI) differed markedly from bupropion and placebo. Bupropion, in contrast to amphetamine, had no peripheral sympathomimetic effects and did not reduce appetite or caloric intake.

Escherichia coli single-strand binding protein organizes single-stranded DNA in nucleosome-like units

Electron microscopy shows that complexes of the single-strand DNA binding protein (SSB) of Escherichia coli and phage fd DNA appear as beaded fiber loops containing an average of 38 beads, 1 per 170 bases of DNA. Extensive digestion of native unfixed SSB-fd DNA complexes with micrococcal nuclease reveals a protected DNA fragment of 145 bases, while shorter digestion periods result in a sequence of fragments in multiples of 160 +/- 25 bases. Digestion of these complexes with DNase I produces a repeating pattern of bands, multiples of approximately 15 bases with strong bands at 60, 105, 118, 130, 145, 150, and 210 bases. Isopycnic banding in CsCl solution yields densities of 1.272 and 1.700 g/ml, respectively, for SSB alone and for fd DNA and, after fixation, of 1.388 g/ml for fd DNA-SSB beaded fibers and 1.373 g/ml for the individual protein-DNA beads. Based on these data and the molecular weights of SSB and fd DNA, we suggest that the nucleoprotein chain consists of eight molecules of SSB bound to 145 bases of DNA, with these units linked by roughly 30 bases of protein-free DNA. The excellent concord between results obtained by enzyme digestion of unfixed native samples and, after fixation, by electron microscopy and density banding supports the conclusion that SSB organizes single-stranded DNA in a manner similar to the organization of duplex DNA by histones.

Electron microscopic visualization of recA-DNA filaments: evidence for a cyclic extension of duplex DNA

As visualized by electron microscopy, RecA protein binds in a highly cooperative manner to single-stranded fd DNA in solutions of 0.01 M Tris (pH 7.5). The resulting nucleoprotein filament loops are 1.25 micrometers in length, have a fiber diameter of 12 nm and show an indication of a 4.5 nm repeat along the axis of the compact fibers. RecA binds to linear duplex fd DNA in solutions of 0.01 M Tris (pH 7.5) to yield chains of beads which, in the presence of Mg2+ and ATP, coalesce into smooth filaments with a length of 1.9 micrometers (the length of protein-free fd duplex DNA) and have a fiber diameter of 12 nm. In solutions containing Mg2+ and ATP-gamma-S, however, RecA binds to duplex DNA in a highly cooperative manner to yield rigid filaments 3.0 micrometers in length. These filaments are 12 nm in diameter and show a very clear 7.5 nm axial repeat. This extension of DNA to 150% of its usual length in the apparent absence of any single-stranded components suggests that the DNA helix must also be highly unwound and provides new insights into the mode of RecA action.

Mechanism of coliphage M13 contraction: intermediate structures trapped at low temperatures

The filamentous coliphage M13 can be transformed into a spherical particle (termed spheroid) by exposure to an interface of water and slightly polar but hydrophobic solvent such as chloroform-water at 24 degrees C. We report here that exposure of M13 filaments to a chloroform-water interface at 2 degrees C trapped the phage particles in forms morphologically intermediate to filaments and spheroids. These structures were rods 250 nm long and 15 nm wide, and each had a closed, slightly pointed end, an open flaired end, and a hollow central channel. The final contraction of these intermediates (termed I-forms) into spheroids was dependent upon both temperature and the presence of the solvent-water interface but was apparently independent of both the minor phage coat proteins and the virion DNA. Although stable in an aqueous environment, I-forms, in contrast to filaments, were readily disrupted by detergents, suggesting that the phage structure had been altered to a form more easily solubilized by membrane lipids. These solvent-induced changes might be related to the initial steps of phage penetration in vivo.

Filamentous bacteriophage contract into hollow spherical particles upon exposure to a chloroform-water interface

The bacteriophage M13 is a 1 micrometer long filament consisting of a circular single-stranded DNA loop firmly held within a tubular protein and capsid. We report here that exposure to a chloroform-water interface initiates a 20 fold contraction of each filament into a hollow protein sphere. In these 0.04 micrometer diameter particles, termed M13 "spheroids," two thirds of the DNA is apparently extruded through a hole in the wall of the spheroid; the portion of DNA remaining inside the shell centers about the origins of M13 DNA replication. These results suggest that the filament, upon exposure to a membrane environment, undergoes an ordered change whereby the DNA is released into the cell and the coat protein is changed to a form more easily solubilized by the membrane lipids.

phiX174 cistron A protein is a multifunctional enzyme in DNA replication

The cistron A protein induced by phage varphiX174 nicks (produces a single-strand break in) the viral strand of the superhelical varphiX duplex DNA, thereby forming a complex with the DNA. The protein, seen bound to the DNA in the electron microscope, was located in the restriction endonuclease fragment between nucleotides 4290 and 4330 on the varphiX map [Sanger, F., Air, G. M., Barrel, B. G., Brown, N. L., Coulson, A. R., Fiddes, J. C., Hutchison, C. A., III, Slocomb, P. M. Y. & Smith, M. (1977) Nature 265, 687-695]. Replication also was initiated at this point, thus identifying the site of cistron A protein nicking and binding as the origin of replication. The cisA-DNA complex (separated from free cistron A protein), upon the addition of Escherichia coli rep protein, ATP, and DNA binding protein, is unwound to generate a single-stranded linear [presumably the nicked (+) strand] and a circular [presumably the (-) strand] molecule. The cisA-DNA complex, upon the further addition of DNA polymerase III holoenzyme and deoxynucleoside triphosphates, supports replication to generate viral, single-stranded circles, as many as 15 circles per cisA-DNA complex. The replicating intermediates seen in the electron microscope are a novel form of "rolling circle" [Gilbert, W. & Dressler, D. H. (1969) Cold Spring Harbor Symp. Quant. Biol. 33, 473-485]. The 5' end (presumably with the cistron A protein bound to it) is locked in the replication fork and loops back to accompany the strand-separation and replication fork around the template [(-) strand] circle. Thus, the multiple functions of cistron A protein include: (i) nicking the viral strand at the origin of replication to initiate a round of replication, (ii) participating in a complex which supports fork movement in strand separation and replication, (iii) nicking again at the regenerated origin to produce a unit-length DNA, and (iv) ligating the newly generated 3'-OH end to the 5'-phosphate-complexed end to form a circular viral molecule.

Salt and divalent cations affect the flexible nature of the natural beaded chromatin structure

A natural chromatin containing simian virus 40 (SV40) DNA and histone has been used to examine changes in chromatin structure caused by various physical and chemical treatments. We find that histone H1 depleted chromatin is more compact in solutions of 0.15M NaCl or 2 mM MgCl2 than in 0.01 M NaCl or 0.6M NaCL, and is compact in 0.01 M NaCl solutions if histone H 1 is present. Even high concentrations of urea did not alter the fundamental beaded structure, consisting of 110A beads of 200 base pair content, each joined by thin DNA bridges of 50 base pairs. The physical bead observed by EM therefore contains more DNA than the 140 base pair "core particle". The natural variation in the bridge length is consistent with the broad bands observed after nuclease digestion of chromatin. Chromatin prepared for EM without fixation containing long 20A to 30A fibers possibly complexed with protein.

Association of a protein structure of probable membrane derivation with HeLa cell mitochondrial DNA near its origin of replication

Almost all (about 95%) of the mitochondrial DNA molecules released by Triton X-100 lysis of HeLa cell mitochondria in the presence of 0.15 M salt are associated with a single protein-containing structure varying in appearance between a 10-20 nm knob and a 100-500 nm membrane-like patch. Analysis by high resolution electron microscopy and by polyacrylamide gel electrophoresis after cleavage of mitochondrial DNA with the endonucleases EcoRI, HindIII, and Hpa II has shown that the protein structure is attached to the DNA in the region of the D-loop, and probably near the origin of mitochondrial DNA replication. The data strongly suggest that HeLa cell mitochondrial DNA is attached in vivo to the inner mitochondrial membrane at or near the origin of replication, and that a membrane fragment of variable size remains associated with the DNA during the isolation. After sodium dodecyl sulfate extraction of mitochondrial DNA, a small 5-10 nm protein is found at the same site on a fraction of the mitochondrial DNA molecules.

Characterization of components released by alkali disruption of simian virus 40

Treatment of simian virus 40 (SV40) particles at pH 9.8 in the presence of 1 mM dithiothreitol for 5 min at 37 degrees C disrupted the virions into a 60S DNA-protein complex and DNA-free 7S protein particles. The DNA-protein complex contained approximately equal amounts of DNA and protein, and appeared by electron microscopy to be relaxed circular structures with an average of 21 beads joined by short, thin bridges. The major protein components in the complex were host cell histones, but SV40-specific proteins VP3 and VP2 were also present. The 7S protein particles were almost exclusively VP1 and, in negatively stained samples, resembled the capsomer structures of intact virions.

Cardiovascular fitness in a selected group of dentists

Thirty-three dentists were studied as part of an exercise rehabilitation clinic in order to evaluate their cardiovascular capacity and coronary prone risk factors. Measurements were made of their physical work capacity, predicted maximal oxygen uptake, fatness, serum lipids and uric acid levels, pulmonary peak flow rates and personality Type A or B. The group as a whole exhibited a moderately high level of fitness and a very active life style which probably reflected their presence at a clinic of this type. Cardiovascular fitness varibles increased with age. This increase may be due to a need and desire on the part of the dentists to maintain their physical fitness as they become older. This need for improved self image may also be a factor in their joining an exercise rehabilitation clinic.

Electron microscope localization of a protein bound near the origin of simian virus 40 DNA replication

A salt-stable complex of protein and viral DNA obtained from Simian virus 40 (SV40)-infected monkey cells or mature SV40 virions has a novel structure. When viewed by high resolution electron microscopy, the circular SV40 DNA molecule has bound to it one to three globular protein "knobs". Using ecoRI and hpaII restriction endonucleases, each of which can cleave SV40 DNA once at a known location (10, 11, 12, 14), the bound protein can be localized at 0.7 plus or minis 0.05 on the SV40 DNA physical map (SV40 fractional length, clockwise from the ecoRI endonuclease-cleavage site).

A case study of psychogenic hoarseness

This paper describes the treatment procedures used with a 40-year-old female with hoarseness of sudden onset. The evidence suggested that the hoarseness was of psychogenic origin. A combination of training in deep muscle relaxation, instruction in phonation in controlled vowel contexts, and gradual reintroduction of a normal voice quality was employed in a hospital setting. Pertinent medical and background information is presented. The patient was seen twice daily for 30-minute sessions on three consecutive days. She achieved a normal voice quality in the fifth session. She was dismissed from the hospital two days later with a normal quality, which she has maintained. There is no subsequent evidence of symptom substitution.