The ovine hypothalamus and pituitary have markedly different distribution of C-type natriuretic peptide forms

C-type natriuretic peptide (CNP) was measured in the hypothalamus and pituitary of four sheep by radioimmunoassay after extraction. The mean concentration of CNP in the hypothalamus was 1.01 +/- 0.08 pmol/g and 45.8 +/- 12.8 pmol/g in the pituitary. Analysis of these extracts by size exclusion HPLC showed the presence of two immunoreactive CNP components that cochromatographed with porcine CNP-53 and CNP-22 standards. Similar amounts of CNP-53- and CNP-22-like IR-CNP were present in the ovine hypothalamus (ratio 0.9:1), whereas in the pituitary, the bulk of the immunoreactive CNP was in the CNP-53-like form. These results show major differences in the distribution of IR-CNP forms between the hypothalamus and pituitary, which may reflect differences in CNP prohormone processing in these two tissues.

How sound is the double-blind design for evaluating psychotropic drugs?

Sufficient data have accumulated to raise serious doubts about the integrity of the double-blind design that is presumed to shield psychotropic drug trials from bias and expectations. A major deficit in most drug trials has been the use of inert rather than active placebos. The deficiencies of the double-blind paradigm call for a questioning stance with respect to previous studies of psychotropic drug efficacy. Various possible ways of strengthening the double-blind paradigm are reviewed.

Assay of brain natriuretic peptide (BNP) in human plasma: evidence for high molecular weight BNP as a major plasma component in heart failure

A RIA for human brain natriuretic peptide (BNP) was developed. Both BNP and atrial natriuretic peptide (ANP) were extracted from human plasma with Vycor glass powder (71% recovery for BNP). The assay had a minimum detection limit of 0.45 fmol/tube and an IC50 of 9 fmol/tube. The within-assay coefficients of variation were 11.4% at 4 pmol/L and 3.2% at 22 pmol/L, and the between-assay coefficient of variation was 11% at 24 pmol/L. There was no significant loss of immunoreactive (IR)-BNP in plasma samples stored at -80 C for 4 weeks. Low rates of labeled BNP and IR-BNP degradation occurred in EDTA plasma incubated at 37 C. The mean venous plasma IR-BNP (6.3 +/- 0.3 pmol/L) in normal subjects (n = 48) was significantly lower than plasma ANP (8.4 +/- 0.6 pmol/L). In contrast to ANP, IR-BNP did not increase when normotensive or hypertensive subjects changed from erect to supine posture. Markedly elevated levels were found in patients with congestive heart failure (mean IR-BNP, 87 +/- 11 pmol/L; ANP, 87 +/- 12 pmol/L; n = 35), recent myocardial infarction (mean IR-BNP, 60 +/- 9 pmol/L; ANP, 33 +/- 6 pmol/L; n = 7), and chronic renal failure. High pressure liquid chromatography of plasma extracts from heart failure subjects revealed both high (mol wt, 10,000) and low (mol wt, 4,000) mol wt IR-BNP. High mol wt BNP was the major component (mean ratio, 1.9:1) and was linearly correlated with low mol wt BNP (r = 0.99). HPLC of plasma extracts from three normal subjects receiving constant infusions of human BNP (2 pmol/kg.min) showed a single major peak eluting in the position of hBNP-32, with no evidence of high mol wt material. These results show that whereas marked elevations in BNP occur in circulatory disorders, a major (> 50%) and consistent contribution to immunoreactivity is due to precursor forms. Further, compared to ANP, there is no IR-BNP response to supine posture in normal and hypertensive subjects.

The significance of the extracellular matrix in intracranial aneurysms

To what extent might change sin the extracellular matrix proteins in intracranial aneurysms (IA) or parent artery (PA) wall contribute to enlargement? Using IA specimens obtained from the coroner's office, the wall structure by light (Trichrome and Actin stains) and immunofluorescent microscopy (IF) (collagen I and fibronectin) have been studied in 18 specimens. It is well known that IA only arise when there is a deficiency in the internal elastic membrane and some breakdown in the media. The results show a normal three layer structure of intima, media, (muscularis), and adventitia in the PA extending out into the neck of the aneurysm. Immunofluorescent stains (IS) show collagen I and fibronectin limited to the adventitia and muscularis, respectively, of the PA and control arteries. The enlarging IA wall shows almost complete loss of this architecture. By IF stain, collagen I and fibronectin are intermingled throughout the IA wall. It is postulated that loss of structure and the confining muscularis layer permit easier elastic enlargement from a more or less homogeneous wall structure.

Social factors influencing performance of a foraging task for captive chimpanzees

The performance of captive chimpanzees (Pan troglodytes) during a simulated foraging activity was compared to that reported for the foraging behavior of wild chimpanzees. The ability to find hidden fruit in a large outdoor play area was measured for 34 subjects housed in ten separate groups. Sex differences were apparent, with females searching for and finding significantly more fruit than males did. Chimpanzees of high and medium dominance rank found more fruit than those of low rank. Neither age nor stage of the female sexual cycle exerted an influence. The subjects became more proficient at finding fruit during the second block of trials. The results reflect possible influences of captivity on chimpanzee social behavior.

A direct comparison of the defense mechanisms of nondepressed people and depressed psychiatric inpatients

This report presents a direct comparison of defensive styles (as measured by the Defense Mechanisms Inventory [DMI]) in a sample of depressed psychiatric inpatients and samples of nondepressed male and female normative groups. Consistent with the "depressive realism" literature, nondepressed men and women were more likely than their depressed counterparts to bias their perceptions in an overly cheerful, optimistic direction. Counternormative sex differences were also found. Depressed men were more likely to use internalizing defenses and depressed women were more likely to use externalizing defenses than their respective nondepressed comparison groups. Overall, as has been speculated, there was a relationship within depressed subjects between depression severity and the amount of negatively biased self-perception.

Ground-based laser radar measurements of satellite vibrations

Vibration signatures from the low-power atmospheric compensation (LACE) satellite are obtained by using the MIT Lincoln Laboratory Firepond coherent CO(2) laser radar facility located in Westford, Mass. The LACE satellite is equipped with IR germanium retroreflectors on deployable/retractable booms to enhance ground-based IR laser radar measurements of on-orbit boom vibrations. Analysis of pulsed cw laser radar measurements of the satellite during and subsequent to boom retraction indicates the presence of a complex time-varying model structure. The observed vibration spectra include vibration modes not previously predicted. These data represent the first observations of satellite vibration modes from a ground-based laser radar.

A meta-analysis of antidepressant outcome under "blinder" conditions

A meta-analysis of 22 studies of antidepressant outcome assessed the level of medication effects under conditions thought to be less subject to clinician bias than those in the typical double-blind drug trial. Studies were included only if, in addition to a newer antidepressant group, they also contained both standard antidepressant and placebo control groups. Effect sizes were quite modest and approximately one half to one quarter the size of those previously reported under more transparent conditions. Effect sizes that were based on clinician outcome ratings were significantly larger than those that were based on patient ratings. Patient ratings revealed no advantage for antidepressants beyond the placebo effect. Effect sizes were unrelated to sample sex ratios, patient age, inpatient or outpatient status, dosage level, and treatment duration. Findings highlight the fragility of the antidepressant effect.

Role of FFA-glucose cycle in glucoregulation during exercise in total absence of insulin

Muscle contraction in vitro increases glucose uptake (GU), independent of insulin, but in vivo, the exercise-induced increase in GU is impaired in insulin-deficient diabetic dogs. We wished to determine whether, in vivo, suppression of the free fatty acid (FFA)-glucose cycle with methylpalmoxirate (MP, inhibitor of FFA oxidation) alone or combined with propranolol (PRO, beta-blocker) could improve GU during exercise in the absence of insulin. We performed four groups of exercise experiments (6 km/h, 10% slope) in depancreatized insulin-deprived dogs: 1) control (n = 6); 2) MP treated (5 oral doses of 10 mg/kg, twice daily, n = 6); 3) treated with MP+octanoate (OCT; oxidation unaffected by MP, 27 mumol.kg-1.min-1 iv during exercise; n = 5); and 4) MP+PRO treated (5 micrograms.kg-1.min-1 iv during exercise, n = 6). MP abolished ketosis (inhibition of hepatic FFA oxidation), decreased basal glucose production (GP), and increased metabolic clearance of glucose (MCR). During exercise, MP attenuated the increment in GP (P < 0.01), which was reversed by OCT. MP did not affect the exercise-induced increase in GU and MCR. With MP+PRO, FFAs decreased and lactate did not rise during exercise. GP was not further suppressed, but GU and MCR were increased (P < 0.01) to 89 and 31% of normal, respectively. In insulin-deprived depancreatized dogs, glucose cycling was increased to a greater extent than GP, as in type II diabetes. By the end of exercise, glucose cycling increased (P < 0.05), but to a similar extent as GP.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypnotizability and recovery from cardiac surgery

We studied 32 coronary bypass patients to examine the effect of hypnosis on recovery from surgery. The patients were assessed for hypnotizability with the Hypnotic Induction Profile (HIP) and assigned to experimental groups with a random stratification procedure to equate for differences in hypnotizability, age, and severity of illness. We taught patients in groups one and two formal hypnosis with different treatment strategies; patients in group three were not taught formal hypnosis or a treatment strategy. Scores on the HIP were significant predictors of recovery, independent of experimental treatment with formal hypnosis. Patients who scored "Midrange" stabilized more quickly in the intensive care unit (ICU) than those who scored "High" or "Low" (p = < .05). Patients who scored "High" had more labile blood pressure in the ICU compared to the "Midrange" and "Lows" (p = < .05). Measured hypnotizability was associated with the recovery sequence from surgery.

Congestive heart failure: survival trial of antiarrhythmic therapy (CHF STAT). The CHF STAT Investigators

This study is a prospective, double-masked, randomized, clinical trial to determine the effect of anti-arrhythmic drug therapy on mortality in patients with congestive heart failure and ventricular arrhythmia. Patients will be assigned to receive either amiodarone or placebo. Eligible patients include those with ischemic and nonischemic congestive heart failure (New York Heart Association class III or VI) and with 10 or more ventricular premature beats per hour. All patients must have shortness of breath with minimal exertion or paroxysmal nocturnal dyspnea, a left ventricular internal dimension (LVIDd) by echocardiogram of 55 mm or greater (> or = 55 mm) or a CT ratio of greater than 0.5, and an ejection fraction of 40% of less. Patients will be entered into the study for 2.5 years and followed for an additional 2 years. Drug therapy will be continued for all patients throughout the entire study unless adverse reactions occur that necessitate individualized treatment. The expectation is that 674 patients are to be entered into the study from 25 participating centers. This sample size will allow for the detection of a 33% decrease in 2-year mortality (20% vs. 30%) in the treated patients as compared to those in the placebo group with a power of 0.90 and a two-sided alpha level of 0.05. Intermittent Holter monitoring, radionuclide ventriculograms, pulmonary function tests, echocardiograms, and blood tests, including arterial blood gases, will be required for each patient. The study analysis will address differences in total mortality, cardiac mortality, and sudden cardiac death between patients receiving anti-arrhythmic drug therapy and those receiving placebo. Other factors to be examined include the effects of antiarrhythmic therapy on suppression of arrhythmias, on ejection fraction, and relation of ischemic events to mortality.

Comparison of three depression rating scales

We directly compared scores on the self-rated Beck Depression Inventory with two other common rating scales that assess a wider range of psychopathology, including depression, the self-rated Symptom Check List-90--R (SCL-90--R), and the clinician-rated Brief Psychiatric Rating Scale for 71 inpatients who suffered from depression (n = 50) and other disorders. All measures of depression showed robust correlations among themselves. The self-rated scales correlated better between themselves than with the clinician-rated scale. Since the SCL-90--R assesses depression as well as the Beck inventories, is also a self-report instrument, yet provides a richer description of psychopathology with little extra effort, it may have some advantage over the latter.

Postmarketing surveillance of adverse drug reactions: patient self-monitoring

BACKGROUND

This report summarizes our experience with a new approach to postmarketing drug surveillance using a pharmacy-based patient self-monitoring strategy, developed in collaboration with Eckerd Drug Company, the American Association of Retired Persons Pharmacy Service, and other pharmacies nationwide.

METHODS

Patients presenting prescriptions to collaborating pharmacies for a targeted drug or a standard drug used as a control received an entry form asking them to register and then call a toll-free telephone number to report possible drug reactions. When contacted by patients, study staff conducted a standardized, computer-driven interview. Two brief mail questionnaires were also employed.

RESULTS

Original validation data gathered from 1984 through 1986 indicated that the most commonly expected adverse drug reactions caused by antibiotic and tricyclic antidepressants reported by 162 self-monitoring patients closely matched those elicited from a comparable control sample of 1109 patients who were independently interviewed by our staff. Results from subsequent studies are also described.

CONCLUSIONS

We believe this method has great promise for providing not only a cost-effective, complementary, early alerting mechanism for detecting adverse drug reactions, but also the additional possibility for discovering unsuspected therapeutic benefits of newly marketed drugs.

A meta-analysis of antidepressant outcome under "blinder" conditions

A meta-analysis of 22 studies of antidepressant outcome assessed the level of medication effects under conditions thought to be less subject to clinician bias than those in the typical double-blind drug trial. Studies were included only if, in addition to a newer antidepressant group, they also contained both standard antidepressant and placebo control groups. Effect sizes were quite modest and approximately one half to one quarter the size of those previously reported under more transparent conditions. Effect sizes that were based on clinician outcome ratings were significantly larger than those that were based on patient ratings. Patient ratings revealed no advantage for antidepressants beyond the placebo effect. Effect sizes were unrelated to sample sex ratios, patient age, inpatient or outpatient status, dosage level, and treatment duration. Findings highlight the fragility of the antidepressant effect.

The focus of pessimism in performance assessments by the depressed

The study concerns the microstructure of pessimistic judgements concerning personal performance in the depressed. The cognitive bias hypothesis was only supported for global estimates of performance and not for trial-by-trial decisions. This weakens the view that there is a fixed cognitive pessimistic bias and leaves open the possibility either that differences relate to the assessment of frequency or to protective strategies operated by the depressed.

18F-2-deoxy-2-fluoro-D-glucose uptake into human tumor xenografts. Feasibility studies for cancer imaging with positron-emission tomography

The positron-emitting glucose analogue 18F-2-fluoro-2-deoxy-d-glucose (FDG) was evaluated for its accretion into the following subcutaneous human tumor xenografts in nude mice: B-cell lymphoma (Namalwa or Raji), ovarian carcinoma (HTB77), colon cancer (SW948), choriocarcinoma (BEWO), bladder cancer (UM-UC-2), renal cell carcinoma (UM-RC-3), neuroblastoma (Mey), melanoma (HTB63), and small cell lung carcinoma (NCI69). Two hours postinjection, tumor uptakes ranged from 0.027 (colon cancer) to 0.125% kg injected dose/g (melanoma); and was greater than 0.085 in the Namalwa lymphomas and the renal cell carcinomas. Tumor-blood ratios of up to 23:1 were seen 2 hours postinjection (melanoma) with a mean tumor-blood ratio for all tumors of 12.3 +/- 1.8. Uptake in the other tumors was intermediate. When evaluated, tumor uptake was slightly greater at 1 than at 2 hours postinjection, although target-background ratios were generally higher at 2 hours postinjection. This compound, FDG, may have broad applicability as a tracer for positron-emission tomographic imaging of many human malignancies.

Expression of the amyloid precursor protein gene in mouse oocytes and embryos

The amyloid precursor protein (APP) is thought to be processed aberrantly to yield the major constituent of the amyloid plaques observed in the brains of patients with Alzheimer disease and Down syndrome. However, the gene encoding APP is expressed widely in normal human tissues and in adult and fetal mouse tissues and is alternatively spliced in a tissue-specific pattern in the adult. There is evidence that APP may function as a growth factor and as a mediator of cell adhesion and in these roles could be important in morphogenesis. As a step toward determining the role of APP in development and in determining how the adult pattern of tissue-specific splicing is established, we have used reverse transcription and the polymerase chain reaction to demonstrate APP expression in mouse oocytes, preimplantation embryos, and postimplantation embryonic stages to the late embryonic period. All three splicing forms described in mouse were present at each stage, although there were changes in the ratios of the splicing forms at different stages. Screens for APP clones in embryonic cDNA libraries from the egg cylinder stage and the early somite stage were used to confirm the results of the polymerase chain reaction, and APP clone abundance was found to increase 10-fold between the two stages.

Ovine atrial natriuretic factor: sequence of circulating forms and metabolism in plasma

The sequence of ovine ANF is not known, yet sheep have been used extensively for ANF studies. We sequenced the circulating form of ovine ANF from coronary sinus plasma of sheep in paced heart failure. The main circulating form was identical to human ANF(99-126). Small amounts of ANF identical to human ANF(103-126) and ANF(101-126) peptides were also found. Incubation of labeled ANF in ovine serum suggested ANF(103-126) could be a degradation product of ANF(99-126). The endopeptidase-24.11 degradation product ANF(99-105/106-126) was not found in ovine plasma, in contrast to human plasma where it was a minor component. These results show that while the main circulating forms are similar in sheep and humans, there are differences in the minor peptides.

Evaluation of tartar control dentifrices in in vitro models of dentin sensitivity

The effects of anticalculus dentifrices were compared with other commercially available dentifrices in in vitro models of dentin sensitivity. Changes in the hydraulic conductance of dentin discs were measured with and without a smear layer before and after treatment and also after a post-treatment acid etch. The capacity of dentifrices to occlude open dentinal tubules in vitro was also assessed by scanning electron microscopy (SEM). There was good correlation (R = 0.98) between our test and values reported in the literature. Tartar control dentifrices gave reductions in fluid flow rates through the dentin discs comparable to those obtained with Promise, Sensodyne, Thermodent and Denquel. Additionally, tartar control dentifrices did not remove microcrystalline debris (smear layers) from the surfaces of dentin in vitro. These results were confirmed by SEM. Thus, according to the hydrodynamic theory of dentin sensitivity, these in vitro results suggest that pyrophosphate-containing dentifrices should reduce dentinal sensitivity.