PubMed Health⌕ Search

Biomedical subjects

M R Block

Publications and source records attributed to M R Block.

At least 55 records · Page 3Linked to original sources
PubMed1987

Teaching the difficult interview in a required course on medical interviewing.

A module dealing with the difficult patient interview is part of a required medical interviewing course for second-year students. Using a classification of difficult doctor-patient interactions, students identify what goes wrong during interviews with simulated patients and then learn techniques to remedy these problems in order to obtain reliable medical histories. Skills taught to the students include identifying the specific problem within an interview and recognizing and using their own feelings as information about the patient. Attitudes encouraged in students include recognizing that the source of the problem may be the patient, the interviewer, or both; that the physician rather than the patient may be the so-called "poor historian"; and that the goal of managing a difficult patient interview is not counseling but rather the acquisition of accurate and precise information.

Education, Medical↗
PubMed1986

Dependence of the conformational state of the isolated adenine nucleotide carrier protein on the detergent used for solubilization.

The mitochondrial adenine nucleotide (AdN) carrier can assume two conformational states that are trapped by the specific inhibitors of AdN transport carboxyatractyloside (CATR) and bongkrekic acid (BA). When the AdN carrier protein was extracted from beef heart mitochondria by the zwitterionic detergent 3-[(3-cholamidopropyl)dimethylammonio)]-1-propanesulfonate (CHAPS) and purified in the same detergent, the fluorescence of the tryptophanyl residue(s) of the protein was partially quenched by ATP (or ADP), but not by nontransportable nucleotides; CATR, which alone was ineffective, was able in the presence of ATP (ADP) to further quench the fluorescence, and BA reversed the quenched fluorescence to the original level. With 3'-O-naphthoyl-ATP (N-ATP) as an extrinsic fluorescence probe, it was shown that BA could release bound N-ATP but that CATR was ineffective. These results indicate that the AdN carrier in CHAPS is able to react readily with BA, but not with CATR. The opposite situation occurs with the carrier solubilized and purified in (laurylamido)-N,N-dimethylpropylamine oxide (LAPAO) [Brandolin, G., Dupont, Y., & Vignais, P.V. (1985) Biochemistry 24, 1991-1997]. These data taken together were interpreted to mean that the CATR and BA conformations of the isolated AdN carrier depend on the micellar structure in which it is embedded; the carrier in LAPAO is in the CATR conformation, and the carrier in CHAPS is in the BA conformation. For the transition between the CATR and BA conformations to occur in the carrier in CHAPS and in the carrier in LAPAO, ATP or ADP is required; nontransportable nucleotides were ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Frames and heuristics in doctor-patient discourse.

The medical interview can be viewed as a verbal exchange between two people trying to solve a problem. Research in linguistics and cognitive psychology casts interesting and useful light on such discourse. Using the concepts 'frames' and 'heuristics' from these fields, we viewed, transcribed and analyzed taped sessions between a family practice physician and sixteen patients to examine how those patients understood their illness. To be an effective teacher the physician must discover not only the causes of the patient's medical problem, but also something of the conceptual structure that supports the patient's perceptions and understanding of his problem. This paper presents a method to understand these conceptual structures and how they function.

Communication↗
PubMed1985

Ethical problems of recording physician-patient interactions in family practice settings.

Recordings of actual physician-patient interactions are an important tool for family medicine education and research. Their use, however, poses two sets of ethical problems: one dealing with privacy and confidentiality, and another related to limitations upon informed consent in the context of ordinary medical care. Experience with audiotaping and videotaping led to engaging in a "principle-based" method of ethical reasoning in which problems generated by difficult cases were examined in light of both current rules or guidelines and four fundamental ethical principles. Through this approach specific policies were developed for voluntary, informed consent and for protection of privacy, while recognizing that each case must be judged in the light of the physician's obligation to do the best for each patient.

Confidentiality↗
PubMed1984

Substrate-site interactions in the membrane-bound adenine-nucleotide carrier as disclosed by ADP and ATP analogs.

The binding parameters of a number of ADP or ATP analogs to the adenine nucleotide carrier in mitochondria and inside-out submitochondrial particles have been explored by means of two specific inhibitors, carboxyatractyloside and bongkrekic acid. The nucleotides tested fell into two classes depending on the shape of the binding curve. Curvilinear Scatchard plots were obtained for the binding of ADP, ATP, adenosine 5'-triphospho-gamma-1-(5-sulfonic acid)naphthylamidate [gamma-AmNS)ATP) and adenylyl (beta,gamma)-methylenediphosphate (p[CH2]ppA); on the other hand, rectilinear Scatchard plots were obtained in the case of naphthoyl-ADP (N-ADP) and 8-bromo ADP (8Br-ADP) binding. The total number of binding sites for N-ADP and 8Br-ADP could be extrapolated with good accuracy to 1.3-1.5 nmol/mg protein; this value corresponds to the number of carboxyatractyloside-binding sites in heart mitochondria (Block, M.R., Pougeois, R. and Vignais, P.V. (1980) FEBS Lett. 117, 335-340). On the other hand, because of the curvilinearity of the Scatchard plots for the binding of ADP, ATP, (gamma-AmNS)ATP and p[CH2]ppA, the total number of binding sites for these nucleotides could only be approximated to a value higher than 1 nmol/mg protein, the exact value being probably equal to that found for N-ADP and 8Br-ADP binding, i.e. 1.3-1.5 nmol/mg protein. Curvilinearity of Scatchard plots was discussed in terms of negative interactions between nucleotide-binding sites located on the same face of the adenine nucleotide carrier. A possible relationship between the features of the binding plots and the transportable nature of the nucleotide is discussed. Contrary to the enhancing effect of bongkrekic acid on [14C]ADP uptake observed essentially in nucleotide-depleted heart mitochondria (Klingenberg, M., Appel, M., Babel, W. and Aquila, H. (1983) Eur. J. Biochem. 131, 647-654), binding of bongkrekic acid to nondepleted heart mitochondria was found to partially displace previously bound [14C]ADP. These opposite effects of bongkrekic acid may be explained by assuming that bongkrekic acid is able to abolish negative cooperativity between external (cytosolic) ADP-binding sites.

Adenosine Diphosphate↗
PubMed1982

Interaction of 3'-O-(1-naphthoyl)adenosine 5'-diphosphate, a fluorescent adenosine 5'-diphosphate analogue, with the adenosine 5'-diphosphate/adenosine 5'-triphosphate carrier protein in the mitochondrial membrane.

3'-O-(1-Naphthoyl)adenosine 5'-diphosphate (N-ADP), a fluorescent analogue of ADP, was established as a potent inhibitor of adenosine 5'-diphosphate/adenosine 5'-triphosphate (ADP/ATP) transport in mitochondria and inside-out sonic particles; the Ki value was about 5 microM. The inhibition was of a mixed type. On the other hand, N-ADP was not transported in a measurable way in either type of particles. Upon binding to the particles, the fluorescent intensity of N-ADP was decreased; the release of the bound N-ADP upon addition of carboxyatractyloside (CATR) to mitochondria and bongkrekic acid (BA) to sonic particles was reflected by increases of fluorescence. In parallel assays dealing with 14C-labeled N-ADP, specifically bound [14C]N-ADP was equated to [14C]N-ADP released upon addition of either CATR (mitochondria) or BA (sonic particles). The specific binding of N-ADP corresponded to 1.4-1.6 nmol/mg of protein in mitochondria, with a Kd value of 3 microM, and to 1.5-1.6 nmol/mg of protein in sonic particles, with a Kd value of 6 microM. Essentially similar values were obtained for N-ATP binding. These values are at least twice as high as those found for specific ADP or ATP binding, suggesting that N-ADP or N-ATP binds to potential nucleotide binding sites that were not totally occupied by ADP or ATP. Whereas nearly all the specifically bound N-ADP in mitochondria was displaced by an excess of ADP (400 microM) at pH 7.4, only 30% could be removed from sonic particles under the same conditions. Furthermore at pH 6.5, no more than half of the specifically bound N-ADP could be removed by excess ADP in mitochondria and only 10-20% in sonic particles. These results indicate that each ADP/ATP carrier unit contains at least two types of nucleotide sites capable of interacting with N-ADP. Because of the hydrophobic nature of the naphthoyl moiety of N-ADP, the data suggest that difference in N-ADP binding in mitochondria and sonic particles are related to differences in the hydrophobic nature of their sites. Due to the special features of N-ADP (strong specific binding to the ADP/ATP carrier and no competence for transport), this DP analogue was particularly suitable for investigating the sensitivity of the nucleotide binding sites of the carrier to chemical modifiers. Inactivation studies were therefore carried out with mitochondria and sonic particles to compare the sensitivity to UV light and butanedione of the binding of N-ADP, [3H]BA, and [14C]Ac-CATR, a radiolabeled substitute for CATR. Both in mitochondria and in sonic particles, UV light and butanedione inactivated more rapidly the binding of N-ADP than that of [3H]BA. On the other hand, in mitochondria, UV light inactivated more rapidly the binding of [14C]Ac-CATR than that of N-ADP; the reverse was true for the inactivation by butanedione. The inactivation data conclusively indicate that BA, CATR, and adenine nucleotides are recognized by different specific sets of amino acids.

Adenosine Diphosphate↗
PubMed1976

Isolated galactorrhea with normal serum prolactin levels: clinical implications.

Detailed endocrine-metabolic studies were performed on five women who were otherwise well but who had had inappropriate breast secretions for variable periods of time (three months to 16 years). Our results suggest that the presence of a lactose-containing breast secretion, which strictly defines galactorrhea, does not necessarily indicate a recognizable abnormality if normal hypothalamic-pituitary function is present. In these regularly menstruating women with isolated galactorrhea, we suggest a minimum initial evaluation, but careful long-term follow-up studies to identify those cases which may progress to the other recognized, more serious amenorrhea-galactorrhea syndromes.

Adult↗
PubMedDate not supplied

The 'usual care' of major depression in primary care practice.

OBJECTIVE: To determine how primary care physicians treat patients with major depression in the course of routine practice and the degree to which such practice produces outcomes anticipated with interventions recommended by the Agency for Health Care Policy and Research Depression Guideline Panel. DESIGNS: Prospective cohort study. SETTINGS: Academically affiliated ambulatory family practice centers and internal medicine clinics in urban neighborhoods of Pittsburgh, Pa. PATIENTS: Ninety-two patients who were seen in primary care practices and who met criteria for a current major depression as determined by the Diagnostic Interview Schedule and a psychiatrist's assessment. INTERVENTION: Physicians were informed of the patient's psychiatric diagnosis, and were urged to treat it in whatever manner and for whatever duration they deemed appropriate (ie, with "usual care"). MAIN OUTCOME MEASURES: The treatments that were provided, the patients' clinical course, and the relationship between the type of treatment and clinical course. RESULTS: Health center records indicated that 67 patients (73%) received a depression-specific treatment in the 8 months following study entry. A majority of the total cohort were prescribed an antidepressant drug. Of the 92 patients, 18 (20%) were asymptomatic at 8 months (Hamilton Rating Scale for Depression score, < or = 7). The treatment pattern was not clearly related to the clinical course. CONCLUSIONS: The recovery rates for the patients with major depression who were treated with usual care in routine primary care practices were lower than those anticipated from treatments consistent with the Agency for Health Care Policy and Research guidelines. Further studies of the caregiving elements that influence the effectiveness of depression-specific treatments of patients in primary care settings are needed.

Adult↗