Biomedical subjects
Publications and source records attributed to D R Johnson.
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Group A streptococci (GAS) are the most frequent cause of pharyngitis in children and are a common cause of emergency room or paediatric clinic visits worldwide. This study determined the representative M and T types of GAS, and their distribution, among schoolchildren in the United Arab Emirates. Throat swabs were taken and cultured for GAS isolates during the winter of 1994-95 from 1000 children aged 5-7 years attending nine schools. Of the isolates obtained, 100 were serotyped using standard techniques. Nearly all these isolates (91%) were T typable, falling into 15 T types; the commonest being type 1 (n = 17), type 6 (n = 15), type 11 (n = 10), type 2 (n = 8), type 12 (n = 8), and type 28 (n = 8). A total of 76% of the isolates were typable for M protein, falling into 14 M types, with type 1 (n = 17), type 6 (n = 15), type 2 (n = 8), type 22 (n = 5), type 28 (n = 7), and type 75 (n = 5) predominating. Serotype clusters were found in certain classes or schools, although the number of isolates examined was too small to allow definitive epidemiological conclusions to be drawn. The ease of serotyping these isolates suggests that GAS strains in the United Arab Emirates are similar, but not necessarily related, to those commonly found in the USA and Europe, and that these may be the most prevalent strains worldwide. The relative prevalence of M type 1 is significant, as this GAS serotype is associated with serious diseases such as rheumatic heart disease, a recognized problem in the United Arab Emirates, and toxic shock syndrome, which has not yet been reported from this area. Knowledge of the prevalence of GAS serotypes, and further research on the epidemiology of streptococcal disease, will be useful should streptococcal vaccines become available.
This study provides the first comprehensive description of Alaska's geographic distribution of generalist physicians relative to population. All 443 generalist care physicians (family, general, general internal medicine, and pediatric) or their office managers were questioned about their specialties, ZIP codes, employers, populations served, and hours spent per week offering direct patient care. The results indicated a 30% overall shortage of generalist physicians for the state, representing roughly 141 full-time-equivalent generalists relative to national practice patterns and trends of health maintenance organizations. Of 17 primary health care areas, including the Anchorage area, 15 showed a need for additional generalist physicians. Most areas had a 20 to 40% shortage. Concerns about transportation and financial barriers to access to care, especially in remote regions, were raised. Other needs emphasized included knowledge of contributions of midlevel health care professionals, Alaska Native versus non-Native care, efforts to train and retain physicians in Alaska, and the need for longitudinal tracking of practice patterns.
Homeobox (hox) genes are of considerable importance in the formation of the body axis of invertebrates and vertebrates. The postulation of a hox-code (i.e. the simultaneous activity of a certain subset of hox genes) for structures at different metameric levels and which differ from each other in shape suggests a relationship between hox-code and shape, which is reinforced by the possibility of homeotic transformation when the hox-code is changed experimentally. This paper considers the possible nature of such a relationship between the hox genes governing vertebral formation in the upper part of the mouse vertebral column and the shape of the adult vertebrae formed in this region.
The responses of vascular endothelial cells (EC) to tumor necrosis factor-alpha (TNF), interleukin-1alpha (IL-1), and phorbol myristate acetate (PMA) were compared with respect to the kinetics of (i) NF-kappaB activation, (ii) IkappaB-alpha and IkappaB-beta degradation, and (iii) NF-kappaB-dependent cell surface molecule expression. TNF rapidly (</=20 min) and persistently (>20 h) activates NF-kappaB; IL-1 rapidly activates NF-kappaB, but activity declines by 3 h and further by 20 h; PMA slowly and transiently activates NF-kappaB. Untreated EC contain the inhibitory proteins IkappaB-alpha and IkappaB-beta. The onset of NF-kappaB activation correlates with degradation of IkappaB-alpha, but IkappaB-alpha reappears by 4 h without resequestration of NF-kappaB. TNF causes a rapid but partial (50%) reduction in IkappaB-beta, which does not recover by 22 h; IL-1 and PMA cause slower and less sustained reductions in IkappaB-beta. All three agonists induce de novo expression of E-selectin (CD62E) and vascular cell adhesion molecule-1 (CD106) and increase expression of intercellular adhesion molecule-1 (CD54) at 4 h. TNF induces sustained increases in vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 and increases human leukocyte antigen class I molecules at 24 h. We conclude that TNF causes persistent activation of NF-kappaB in human EC and that this may result from sustained reductions in IkappaB-beta levels.
Transporter associated with Ag processing-1 (TAP1) is induced by IFN-gamma more rapidly than is HLA class I. Kinetic analysis of transfectants reveals that IFN-gamma activates the TAP1 promoter more rapidly than the HLA-B7 class I promoter. A gamma-activating sequence (GAS) in the TAP1 promoter is necessary for the rapid induction by IFN-gamma. Two overlapping IFN consensus sequences contribute to the constitutive and TNF-induced expression of TAP1 but are not necessary for the IFN-gamma response. Moreover, IFN-gamma activates the GAS-binding protein Stat1 alpha much more rapidly than it induces the IFN consensus sequence-binding protein IRF-1, which mediates the response of the HLA-B7 class I promoter. We conclude that IFN-gamma uses different transcription factors to regulate the sequence of appearance of these interacting gene products.
STUDY OBJECTIVE: To determine how accurately paramedics interpret common lung sounds on an audiotape in comparison with emergency physicians. METHODS: We carried out a prospective comparison of blinded lung sound interpretation using a standard teaching tape. Our subjects were 67 experienced paramedics and 22 new paramedics from urban and suburban emergency medical services systems comprising municipal and private ambulance providers; and 18 emergency physicians. Five common lung sounds were played three times, in different sequences, and with additional patient history provided for each repetition. The members of each group listened to the same tape and were asked to identify the lung sounds. RESULTS: Emergency physicians had a median score of five of five possible correct responses in each of the three trials. This score was significantly higher than those of experienced and new paramedics. Experienced paramedics (P = .001) and new paramedics (P = .002) significantly increased their median scores over the three trials with additional medical history. We found no significant difference between experienced and new paramedics in any of the three trials. CONCLUSION: In our study, paramedics did not assess lung sounds as accurately as emergency physicians, and experienced paramedics did not interpret sounds more accurately than new paramedics. Correct identification of lung sounds improved significantly for paramedics when medical history was known.
In this study, comparison of a vacuum splint device to a rigid backboard was made with respect to comfort, speed of application, and degree of immobilization. The study was a prospective, nonblinded comparative study conducted at a statewide emergency medical services (EMS) training facility and included a convenience sample of emergency medical technician (EMT) and paramedic students. The vacuum splint was judged to be significantly more comfortable on a 10-point scale than the rigid backboard after subjects had been lying on each device for 30 minutes (P < .001). It was also faster to apply: 131.6 +/- 24.3 seconds versus 154.6 +/- 22.2 seconds (P < .001). Various measures of immobilization were similar for the two devices. The vacuum splint provided better Immobilization of the torso and less slippage on a gradual lateral tilt. The rigid backboard with head blocks was slightly better at immobilizing the head. Vacuum splints offer a significant improvement in comfort over a traditional backboard for the patient with possible spinal injury. They can be applied in reasonable time frames and provide a similar degree of immobilization when compared to a standard rigid backboard.
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OBJECTIVE: This study analyzed the outcome of a 4-month intensive inpatient program for combat-related posttraumatic stress disorder (PTSD) among Vietnam veterans. METHOD: The subjects were 51 male veterans with PTSD who completed the inpatient treatment program. Comprehensive measures of PTSD and psychiatric symptoms, as well as social functioning, were assessed at admission, discharge, and 6, 12, and 18 months after discharge. RESULTS: The overall study group showed an increase in symptoms from admission to follow-up and a decrease in violent actions and thoughts and legal problems. Family and interpersonal relationships and overall morale were improved at discharge but then returned to pretreatment levels at 18 months. Patient evaluations also indicated that the program affected morale and interpersonal relationships but not symptoms. CONCLUSIONS: The chronic nature of combat-related PTSD among Vietnam veterans is evident. The study raises the possibility that long-term intensive inpatient treatment is not effective, and other forms of treatment should be considered after rigorous study of such variables as length of stay, trauma versus rehabilitation focus, and patient characteristics.
In the recent revision of the AAMR classification manual, an adapted version of Greenspan's model of personal competence was used to describe personal capabilities. This adapted model differs significantly from the original Greenspan model. In the present study three alternative models of personal competence were evaluated with confirmatory factor analysis methods in separate samples of 180 students with mild and 143 students with moderate to severe disabilities. The results supported Greenspan's original model that includes the domains of physical and emotional competence and practical, social, and conceptual intelligence. The AAMR model that includes the construct of adaptive skills was not supported.
Four unlinked fatty acid activation (FAA) genes encoding acyl-CoA synthetases have been identified in Saccharomyces cerevisiae and characterized by noting the phenotypes of isogenic strains containing all possible combinations of faa null alleles. None of these genes is required for vegetative growth when acyl-CoA production by the fatty acid synthetase (Fas) complex is active. When Fas is inhibited by cerulenin, exponentially growing cells are not viable on media containing a fermentable carbon source unless supplemented with fatty acids such as myristate, palmitate, or oleate. The functionally interchangeable FAA1 and FAA4 genes are responsible for activation of these imported fatty acids. Analysis of lysates prepared from isogenic FAA1FAA4 and faa1 delta faa4 delta strains indicated that Faa1p and Faa4p together account for 99% of total cellular myristoyl-CoA and palmitoyl-CoA synthetase activities. Genetic complementation studies revealed that rat liver acyl-CoA synthetase (RLACS) rescues the viability of faa1 delta faa4 delta cells in media containing a fermentable carbon source, myristate or palmitate, plus cerulenin. Rescue is greater at 37 degrees C compared with 24 degrees C, paralleling the temperature-dependent changes in RLACS activity in vitro as well as the enzyme's ability to direct incorporation of tritiated myristate and palmitate into cellular phospholipids in vivo. Complementation by RLACS is blocked by treatment of cells with triacsin C (1-hydroxy-3-(E,E,E,2',4',7'- undecatrienylidine)triazene). Even though Faa1p, Faa4p, and RLACS are all able to activate imported myristate and palmitate in S. cerevisiae, the sensitivity of Faa4p and RLACS, but not Faa1p, to inhibition by triacsin C suggests that the rat liver enzyme is functionally more analogous to Faa4p than to Faa1p. Finally, an assessment of myristate and palmitate import into FAA1FAA4 and faa1 delta faa4 delta strains, with or without episomes that direct overexpression of Faa1p, Faa4p or RLACS, indicated that fatty acid uptake is not coupled to activation in S. cerevisiae.
The predominant type of cell division in adult mammals is renewal growth. Renewing stem cells in somatic tissues undergo continuous asymmetric divisions. One new daughter cell retains the division potential of the original stem cell, while the other differentiates into a functional constituent of the tissue. Disruptions of this process lead to the development of human cancers. We show that through a guanine nucleotide-dependent mechanism, the p53 antioncogene can induce exponentially dividing cells to switch to an asymmetric stem cell growth pattern. This finding suggests that the observed high frequency of p53 mutations in human cancers reflects a critical function in the regulation of somatic renewal growth.
The therapeutic purposes and effects of specially designed ceremonies in the treatment of persons with post-traumatic stress disorder are described. Ceremonies compartmentalize the review of the trauma, provide symbolic enactments of transformation of previously shattered relationships, and reestablish connections among family and with society in general. Four ceremonies used with Vietnam combat veterans are described which focus on the themes of separation from and return to the family, forgiveness of the living, and releasing the dead. Ritual and ceremony are highly efficient vehicles for accessing and containing intense emotions evoked by traumatic experience. Evaluation by family and veterans judge these ceremonies to be the most effective components of treatment.
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Two patients without clinical evidence of malignancy had idiopathic migratory thrombophlebitis. A clinical state consistent with Trousseau's syndrome prompted a work-up of each patient for occult cancer. In both individuals, computed tomography of the chest revealed a solitary mediastinal lymph node that, though inconspicuous, was evaluated further because of the clinical picture. Mediastinoscopy with biopsy revealed poorly differentiated carcinoma. Treatment was begun for carcinoma of unknown primary with variable response to therapy. The clinical presentation and pathophysiology of Trousseau's syndrome, as well as its use in leading to an antemortem diagnosis of occult cancer in these and other patients, are delineated.
There is a need for family therapy interventions that are specific to the conditions found in families of traumatized people such as combat veterans. In these families, the historically "real" event of the trauma often continues to exert influence on the family system despite collusive arrangements that serve to keep it hidden. In families of combat veterans, a situation develops whereby the veteran becomes triangulated with a dead buddy without the spouse's knowledge. The discrepancy between past and present emerges in what we call the critical interaction between the spouses. This article outlines a method of couples therapy that attempts to demystify this critical interaction, and begins to integrate the discrepant narratives of each spouse. The establishment of a nascent mutuality of perspective within the couple releases energies that can be directed toward support rather than symptom-formation in the family system.
OBJECTIVES: To assess the hydration status of women presenting to an ED with hyperemesis gravidarum and to determine whether clinically relevant changes in orthostatic vital signs occur. METHODS: A convenience sample of 23 pregnant women who had hyperemesis gravidarum, with each patient serving as her own control. The study took place in the ED observation unit of an urban teaching hospital. Women who had pregnancies of < or = 16 week's gestation who had been vomiting for at least 24 hours were included. Supine and standing pulse rates and blood pressures (BPs) were measured sequentially after 5 minutes in each position. Patient weight and urine specific gravity (SG) also were recorded. After 6 L of lactated Ringer's solution was infused over a 12-hour period, the same measurements were repeated. Pre- and posthydration changes were analyzed using the paired t-test. RESULTS: The mean treatment weight gain as a percentage of the total body weight was 5.6% +/- 2.2% (mean +/- SD). The urine SG decreased from 1.027 +/- 0.004 to 1.008 +/- 0.003 (p < 0.001). The mean change in systolic BP upon assuming the standing position was -8.3 +/- 12.7 mm Hg before hydration vs 2.9 +/- 7.8 mm Hg after hydration (p < 0.001). The corresponding change in mean diastolic BP was 3.7 +/- 10.9 mm Hg before hydration vs 8.6 +/- 10.9 mm Hg after hydration (p = 0.12). The mean change in pulse rate upon standing was 26.8 +/- 14.5 beats/min before hydration vs 14.5 +/- 10.1 beats/min after hydration (p = 0.002). CONCLUSIONS: Women who present to the ED with hyperemesis gravidarum are significantly dehydrated and experience measurable improvement in postural pulse rate and systolic BP changes with rehydration. However, the presenting orthostatic changes lack sufficient sensitivity to be effectively used as quantitative screening tests for dehydration.