Biomedical subjects
Publications and source records attributed to A M Thomas.
Strategic planning identifies a department's environmental factors while establishing its purpose, mission, philosophy and goals and developing a long-range plan and objectives. This hospital's practical approach mirrors the nursing process related to assessment, diagnosis and planning, implementation and evaluation.
Patients with non-fear panic disorder (NFPD) meet DSM-III-R criteria for panic disorder, but do not report subjective fear or anxiety. Although apparently common in medical settings, this controversial group is in need of further diagnostic validation. This study assessed family history of panic disorder in patients with chest pain and normal coronary arteries (CP/NCA) and either NFPD, panic disorder with fear, or no panic. It was hypothesized that the two panic disorder groups would have similar, elevated rates of panic disorder in their first-degree relatives, compared to patients without panic. The results support the hypothesis; about 17% of the first-degree relatives of both NFPD and panic disorder patients were diagnosable with panic disorder according to proband interviews, whereas only 4.6% of the first-degree relatives of patients without panic were so diagnosable. These results support the diagnostic validity of NFPD in CP/NCA patients, because such patients had a family history of panic disorder similar to patients with a more classical panic disorder presentation. The lack of fear symptoms and behavior in NFPD may cause panic disorder to be overlooked as a potential cause of somatic symptoms in patients with no medical explanation for their condition.
OBJECTIVE: The authors evaluated the diagnostic validity of an interview-based panic disorder diagnosis in cardiology chest pain patients with angiographically normal coronary arteries. METHOD: Patient probands with normal coronary arteries (N = 65) were first contracted immediately after their normal angiogram and were given a structured diagnostic interview. On the basis of the results of the interview, probands were grouped as having panic disorder (N = 19), panic attacks that did not meet frequency criteria for panic disorder (N = 17), or no panic (N = 29). At a later time, patient probands were recontacted and given a structured family history interview that inquired about psychopathology in their first-degree biological relatives (N = 544). RESULTS: As predicted, panic disorder was significantly more prevalent among the first-degree relatives of probands with normal coronary arteries diagnosed with panic disorder or panic attacks than among the family members of probands with normal coronary arteries without panic (17.4% versus 15.7% versus 4.0%). Family members of probands with panic attacks were significantly more likely to be diagnosed with major depression than were the family members of probands with no panic; however, differences did not reach significance for family members of the panic disorder proband group. Groups did not differ significantly in familial alcoholism. CONCLUSIONS: These data support the construct validity of an interview-based panic disorder diagnosis among patients with chest pain and normal coronary arteries and suggest that these patients could benefit from treatment for panic disorder.
OBJECTIVES: Several interview studies have suggested that panic disorder (PD) exists in patients with angiographically normal coronary arteries (NCA). Interview studies require corroboration by other studies in order to validate them. The purpose of this study is to test whether response to the inhalation of 35% CO2 reliably discriminates between PD and non-panic disorder patients in this population. METHOD: Three groups were studied: six with NCA and PD, five with NCA and no PD, and ten in the control group. All subjects breathed room air, then 35% CO2 in a single-blind fashion. Each completed the Acute Panic Inventory (API) before and during the procedure. RESULTS: The NCA-panic group scored significantly higher than the other two groups on the Acute Panic Inventory from baseline to post-inhalation. CONCLUSION: Despite several methodological limitations including a relatively small number people in each cells, 35% CO2 was shown to trigger more intense responses in panic patients, thus helping to validate the interview findings.
The purposes of this study were to examine young adolescent functioning over a 2-year period after divorce and to assess the role of two family factors, interpersonal conflict and the parent-adolescent relationship, in predicting such functioning. One hundred and twelve young adolescents, their mothers, and their social studies teachers served as participants. One-half of the adolescent were from recently divorced families and one-half were from married families. Mothers completed measures concerning interparental conflict and the parent-adolescent relationship, adolescents completed a measure of the relationship, and teachers completed measures assessing four areas of adolescent functioning. The results indicated that adolescents from divorced families were functioning less well than those from married families. There were no changes in adolescent functioning and the parent-adolescent relationship from the first to second year postdivorce. High levels of interparental conflict in divorced families were associated with more parent-adolescent relationship problems. In turn parent-adolescent relationships problems served as the best predictor of concurrent and subsequent difficulty in adolescent functioning.
The kinetic behavior and pH-stability of recombinant human renin was analyzed using a new fluorogenic substrate based on the normal P6-P3' renin cleavage sequence in human angiotensinogen. The design of this fluorogenic substrate makes possible, for the first time, direct monitoring of the kinetics of proteolytic conversion of prorenin to renin. The pH-stability profile for renin, measured with the substrate at 25 degrees C, indicated a broad plateau of stability between pH 6.0 and 10.0. Analysis of the pH-activity profile of renin for the substrate indicated a minimum Km (approximately 1.8 microM) at pH approximately 7.4 and a maximum Vm between pH 7.4 and 8.0. The thermodynamics of the binding of a novel, soluble, peptidomimetic inhibitor to renin indicated it is possible to retain the tight-binding characteristics and enthalpy contributions to binding of larger peptide-derived inhibitors, while reducing inhibitor size and entropic contributions to binding. A novel derivative of the fluorogenic substrate, containing a 3-methyl histidine substitution at the P2 site, was used to test the recent hypothesis that renin functions by virtue of substrate-directed catalysis.
The effect of mechanical vibration in the frequency range 0-500 Hz on the cadaveric human femur was assessed. It was found that when the bone was fixed at both ends, its resonant frequency was markedly affected by end loading and damping. If the conditions of the experiment were designed to simulate the condition of the femur when prepared for a total hip replacement, it was found that the bone did not resonate but behaved in a mass-like mode. The significance of this observation is that in the event of vibration being applied to enhance the penetration of bone cement, the movement induced in the bone will be proportional to the force applied regardless of frequency. This also demonstrates that the concept of designing a prosthesis so that it is isoelastic with the femur is complex and potentially flawed, since the stiffness of the femur will vary during the walking cycle.
This article describes validating studies for diagnosing panic disorder in some patients with angiographically normal coronary arteries (NCA) and chest pain. Psychiatric interviews of 94 such patients showed that 34% met the diagnostic criteria for panic disorder. Further studies showed that NCA patients with panic disorder were more disabled at 3.5-year follow-up, had more relatives with panic disorder, were more likely to suffer from major depression, and were more likely to respond to 35% CO2 challenge with panic symptoms. Because panic disorder is highly disabling but responds well to psychological and pharmacologic treatments, screening NCA patients in the cardiology population for this disorder is recommended.
This study examined the association between cumulative family stressors (divorce, interparental conflict, maternal depression) and adolescent functioning as well as the protective role of the parent-adolescent relationship as perceived by the adolescent when family stressors are present. Two hundred and thirty-one adolescents, their mothers, and their social studies teachers served as the subjects. Results indicated that, as family stressors increased, adolescent functioning deteriorated. Furthermore, a positive parent-adolescent relationship as perceived by the adolescent was associated with less deterioration in all areas of functioning. The role of the relationship in protecting the adolescent supported both a stress buffering model and a main effect model.
The synthesis, receptor binding, and agonist activity of a series of truncated atrial natriuretic analogs (ANF) are described. These analogs incorporate two portions of the native 28 amino peptide, the eight amino acids C-terminal to Cys7, and two amino acids from the C-terminus (phenylalanine and arginine), into disulfide-bonded cyclic peptides. The inclusion of the C-terminal amino acids converted the ANF analogs from receptor ligands to full agonists, as measured by several methods, including the stimulation of cGMP biosynthesis in endothelial cells, inhibition of aldosterone biosynthesis in rat adrenal cells, and natriuretic-hypotensive activity in vivo. The most potent analogs have cyclohexylalanine (Cha) at position 8. The lead compound (Arg6,Cha8 ANF 6-15 Phe-Arg-Cys-NH2) is a tridecapeptide that integrates the C-terminal amino acids inside the disulfide ring. This peptide, designated as A-68828, has a binding affinity of IC50 = 120 nM, approximately 1/400 of ANF 1-28. However, this analog, in vivo, is only slightly less natriuretic (1/20-1/50) than ANF 1-28. Unlike the native peptide, A-68828 is only mildly hypotensive and at the highest concentration tested reduced blood pressure less than 15 mmHg (1 mmHg = 133.322 Pa). A-68828 inhibited ACTH-induced aldosterone release to a greater extent than ANF 1-28: 100 vs. 50%. The selective natriuretic activity of A-66828, relative to ANF, suggests clinical utility for the treatment of acute renal failure.
1. Older people living in the community often describe incontinence as an unpleasant nuisance, something to be managed but seldom talked about. Few of the respondents in this study limited their activities because of incontinence. 2. The respondents managed incontinence using a variety of self-care practices, including commercial and homemade pads, fluid restriction, and toileting routines. 3. Nurses had little, if any, impact on the experience of incontinence for these respondents. It is important for older people to have access to knowledgeable health-care professionals and appropriate strategies and products.
Haemangioma of bone is a rare benign tumour of blood vessels. We report a case arising in a middle phalanx and the problems encountered in its management.
While divorce has been associated with impaired child functioning, the mechanisms within the divorce process leading to such an outcome have rarely been examined. The following hypothesis was examined: Divorce is associated with poor parental adjustment or disrupts parenting behavior, or both, which leads to poor adolescent functioning. Subjects were 121 and 93 young adolescents from intact and recently divorced families, respectively, and their mothers and teachers. Mothers completed measures assessing parental conflict and depression, observers coded parenting skills during a mother-adolescent interaction, and teachers completed measures assessing adolescent functioning. Although the magnitude of differences was not large, analyses of variance indicated that the divorced sample was functioning poorer than the married sample on all measures except interparental conflict. Path analysis suggested that parental functioning and parenting skills play a role in adolescent functioning following divorce.
The maximum pullout force in the distal metaphysis of cadaver femurs was investigated using a commercially available, pneumatically inserted staple. In paired studies, a significantly greater pullout force was required in the power-driven staples than in an almost identical sized hand-driven staple. A nonlinear relationship was shown to exist between staple-leg length and maximum pullout force.
The present study was concerned with the development and testing of a structural equation model wherein the relation of interparental conflict to the adjustment problems of young adolescents is mediated through its impact on 3 aspects of parenting behavior: lax control, psychological control, and parental rejection/withdrawal. The model was tested separately on a sample of 46 young adolescents from intact families and a group of 51 adolescents from recently divorced families. The hypothesis that most of the relation between martial conflict and adolescent adjustment problems could be explained through perturbations in the parent-child relationship received considerable support; the only direct effect of conflict was on externalizing problems in the intact sample. The results also suggested that the mediational patterns were somewhat different for the 2 samples, and that the model accounts for a greater proportion of the variance in the adjustment problems of adolescents from intact homes than of those from recently divorced families.
A collection of analogues of atrial natriuretic peptide (ANP) were screened for their ability to inhibit ANP-induced cGMP stimulation. The antagonists revealed through this screen are structurally related; almost all are substituted at either aspartate-13 or phenylalanine-26. This tendency is consistent throughout several families of small ANP analogues, suggesting that these two amino acid residues are involved in the process of ANP/cGMP signal transduction. One compound, A74186, was studied in some detail. A74186 is a potent inhibitor of the activation of guanylate cyclase by ANP; it acts with a pA2 of 7.12 in rat vascular smooth muscle cells and shifts the ANP/cGMP dose-response curve by 3 orders of magnitude at a 10 microM concentration. It also inhibits cGMP release in vivo, and at an infusion rate of 10 micrograms/kg-min it completely abolishes ANP-induced natriuresis and diuresis. A74186 does not, however, antagonize the hypotensive or vasorelaxant effects of ANP; in fact it acts as an agonist in these assays. It thus appears that cGMP, although it may mediate the renal responses to ANP, is not responsible for the vascular and hemodynamic effects that result from the action of the hormone.
A microcomputer-based system has been designed to interview patients with a view to investigating and establishing common syndromes of back and leg pain. In a randomized crossover validation study, 50 consecutive outpatients were interviewed by the computer and had a conventional clerking by a doctor. The conventional clerking made minor errors in 3.75% of questions answered and major errors in 0.90%. The computer made minor errors in 6.75% of questions and major errors in 5.45%. The majority of the computer errors were due to inadequate question design. These have been corrected, and it is anticipated that the computer will now have an overall rate of 94% correct answers and be sufficiently accurate to pursue the aim of clinical syndrome identification.
Phosphorus-31 magnetic resonance (MR) spectroscopy was performed on the liver of patients with alcoholic hepatitis (n = 10), alcoholic cirrhosis (n = 9), and viral hepatitis B (n = 3) and on healthy control subjects (n = 21). A hydrogen-1 MR image-guided localization technique (ISIS) was used to acquire P-31 spectra selectively from a volume of interest within the liver. Spectra were analyzed to yield absolute molar concentrations of hepatic phosphomonoesters, phosphodiesters, inorganic phosphate, and adenosine triphosphate. It was found that (a) hepatic metabolite ratios in alcoholic liver disease were not significantly different from those in healthy subjects, (b) absolute hepatic metabolite concentrations were decreased by 25%-46% in alcoholic hepatitis and 13%-50% in alcoholic cirrhosis compared with those in healthy subjects, and (c) hepatic intracellular pH was 7.4 in healthy subjects, more acidic in alcoholic cirrhosis, and more alkaline in alcoholic hepatitis. The findings indicate that hepatic metabolite ratios are not a sensitive measure of alcoholic liver disease, that quantitative P-31 MR spectroscopy is able to noninvasively show metabolic changes associated with alcoholic liver disease, and that alcoholic hepatitis and cirrhosis may be distinguished by means of hepatic intracellular pH measured with MR spectroscopy.