An in-depth look at latent classes of DSM-5 psychiatric comorbidity among individuals with PTSD: Clinical indicators and treatment utilization

OBJECTIVE

Posttraumatic stress disorder (PTSD) is associated with high comorbidity rates across the full range of psychiatric disorders. However, little is known about how psychiatric comorbidity manifests among people with PTSD, particularly with regard to concurrent diagnoses.

METHOD

Latent class analysis (LCA) was used to characterize discrete classes of PTSD comorbidity using past year DSM-5 diagnostic standards among a large nationally representative epidemiologic sample of U.S. adults. Follow-up analyses compared participant characteristics across latent classes.

RESULTS

The LCA was best characterized by five classes: low comorbidity, distress-fear, distress-externalizing, mania-fear-externalizing, and mania-externalizing. Excluding the low comorbidity class, proportions of borderline and schizotypal personality disorder were high across classes.

CONCLUSION

Participant characteristics across classes of past year PTSD comorbidity are explored through the lens of case conceptualization and treatment planning utility.

Prolonged Exposure and Sertraline Treatments for Posttraumatic Stress Disorder Also Improve Multiple Indicators of Social Functioning

Trauma survivors with posttraumatic stress disorder (PTSD) frequently also suffer from difficulties in social functioning that range across emotional, cognitive, and environmental domains. A detailed evaluation of the differential impacts of effective PTSD treatments on social functioning is needed. Men and women (N = 200) with chronic PTSD received 10 weeks of prolonged exposure (PE) or sertraline in a randomized clinical trial and were followed for 24 months. A secondary data analysis examined changes in social functioning with regard to fear of intimacy; receipt of social support; and distress, avoidance, and negative cognitions in social situations. Effects were examined between treatments over time, controlling for baseline functioning. There were large, durable improvements across all indices. Compared to sertraline, PE was more efficient at reducing fear of intimacy and distress from negative social cognitions by posttreatment, ds = 0.94-1.14. Patients who received sertraline continued to improve over the course of follow-up, ds = 0.54-1.17. The differential speed of therapeutic effects may argue for more direct mechanisms in cognitive behavioral interventions versus cascade effects in serotonin reuptake inhibitors. Notably, both treatments produced substantial social benefits for trauma survivors with social functioning difficulties, and effect sizes were comparable to typical reductions in PTSD, depression, and anxiety.

High expectancy and early response produce optimal effects in sertraline treatment for post-traumatic stress disorder

BACKGROUND

Better indicators of prognosis are needed to personalise post-traumatic stress disorder (PTSD) treatments.AimsWe aimed to evaluate early symptom reduction as a predictor of better outcome and examine predictors of early response.

METHOD

Patients with PTSD (N = 134) received sertraline or prolonged exposure in a randomised trial. Early response was defined as 20% PTSD symptom reduction by session two and good end-state functioning defined as non-clinical levels of PTSD, depression and anxiety.

RESULTS

Early response rates were similar in prolonged exposure and sertraline (40 and 42%), but in sertraline only, early responders were four times more likely to achieve good end-state functioning at post-treatment (Number Needed to Treat = 1.8, 95% CI 1.28-3.00) and final follow-up (Number Needed to Treat = 3.1, 95% CI 1.68-16.71). Better outcome expectations of sertraline also predicted higher likelihood of early response.

CONCLUSIONS

Higher expectancy of sertraline coupled with early response may produce a cascade-like effect for optimal conditions for long-term symptom reduction. Therefore, assessing expectations and providing clear treatment rationales may optimise sertraline effects.

DECLARATION OF INTEREST

None.

The Evolving Construct of Posttraumatic Stress Disorder (PTSD): DSM-5 Criteria Changes and Legal Implications

In the DSM-5, the diagnosis of posttraumatic stress disorder (PTSD) has undergone multiple, albeit minor, changes. These changes include shifting PTSD placement from within the anxiety disorders into a new category of traumatic and stressor-related disorders, alterations in the definition of a traumatic event, shifting of the symptom cluster structure from three to four clusters, the addition of new symptoms including persistent negative beliefs and expectations about oneself or the world, persistent distorted blame of self or others, persistent negative trauma-related emotions, and risky or reckless behaviors, and the addition of a dissociative specifier. The evidence or lack thereof behind each of these changes is briefly reviewed. These changes, although not likely to change overall prevalence, have the potential to increase the heterogeneity of individuals receiving a PTSD diagnosis both by altering what qualifies as a traumatic event and by adding symptoms commonly occurring in other disorders such as depression, borderline personality disorder, and dissociative disorders. Legal implications of these changes include continued confusion regarding what constitutes a traumatic stressor, difficulties with differential diagnosis, increased ease in malingering, and improper linking of symptoms to causes of behavior. These PTSD changes are discussed within the broader context of DSM reliability and validity concerns.

Sex differences in fear conditioning in posttraumatic stress disorder

BACKGROUND

Women are twice as likely as men to develop Posttraumatic Stress Disorder (PTSD). Abnormal acquisition of conditioned fear has been suggested as a mechanism for the development of PTSD. While some studies of healthy humans suggest that women are either no different or express less conditioned fear responses during conditioning relative to men, differences in the acquisition of conditioned fear between men and women diagnosed with PTSD has not been examined.

METHODS

Thirty-one participants (18 men; 13 women) with full or subsyndromal PTSD completed a fear conditioning task. Participants were shown computer-generated colored circles that were paired (CS+) or unpaired (CS-) with an aversive electrical stimulus and skin conductance levels were assessed throughout the task.

RESULTS

Repeated measures ANOVA indicated a significant sex by stimulus interaction during acquisition. Women had greater differential conditioned skin conductance responses (CS + trials compared to CS- trials) than did men, suggesting greater acquisition of conditioned fear in women with PTSD.

CONCLUSIONS

In contrast to studies of healthy individuals, we found enhanced acquisition of conditioned fear in women with PTSD. Greater fear conditioning in women may either be a pre-existing vulnerability trait or an acquired phenomenon that emerges in a sex-dependent manner after the development of PTSD. Characterizing the underlying mechanisms of these differences is needed to clarify sex-related differences in the pathophysiology of PTSD.

Early care limitations independently predict mortality after intracerebral hemorrhage

OBJECTIVE

Intracerebral hemorrhage (ICH) is associated with a high early mortality rate. We examined the impact of early do not resuscitate (DNR) orders and other limitations in aggressive care on mortality after ICH in a community-based study.

METHODS

Cases of spontaneous ICH from 2000 to 2003 were identified from the Brain Attack Surveillance in Corpus Christi (BASIC) project, with deaths ascertained through 2005. Charts were reviewed for early (<24 hours from presentation) DNR orders, withdrawal of care, or deferral of other life sustaining interventions, analyzed together as combined DNR (C-DNR). Multivariable Cox-proportional hazards models were used to examine the association between short- and long-term all-cause mortality and early C-DNR, adjusted for demographics and established predictors of mortality after ICH.

RESULTS

Of 18,393 subjects screened for cerebrovascular disease, 270 non-traumatic ICH cases were included. Cumulative mortality risk was 0.43 at 30 days and 0.55 over the study course. Early C-DNR was noted in 34% of cases and was associated with a doubling in the hazard of death both at 30 days (hazard ratio [HR] 2.17, 95% CI 1.38, 3.41) and at end of follow-up (HR 1.92, 95% CI 1.29, 2.87) despite adjustment for age, gender, ethnicity, Glasgow Coma Scale, ICH volume, intraventricular hemorrhage, and infratentorial hemorrhage.

CONCLUSIONS

Early care limitations are independently associated with both short- and long-term all-cause mortality after intracerebral hemorrhage (ICH) despite adjustment for expected predictors of ICH mortality. Physicians should carefully consider the effect of early limitations in aggressive care to avoid limiting care for patients who may survive their acute illness.

Differences in intracerebral hemorrhage between Mexican Americans and non-Hispanic whites

BACKGROUND

Mexican Americans (MAs) have higher incidence rates of intracerebral hemorrhage (ICH) than non-Hispanic whites (NHWs). The authors present clinical and imaging characteristics of ICH in MAs and NHWs in a population-based study.

METHODS

This work is part of the Brain Attack Surveillance in Corpus Christi (BASIC) project. Cases of nontraumatic ICH were identified from 2000 to 2003. Multivariable logistic regression was used to assess the independent associations between ethnicity and ICH location (lobar vs nonlobar) and volume (> or = 30 vs < 30 mL), adjusting for demographics and baseline clinical characteristics. Logistic regression was also used to determine the association between ethnicity and in-hospital mortality, adjusting for confounders.

RESULTS

A total of 149 MAs and 111 NHWs with ICH were identified. MAs were younger (70 vs 77, p < 0.001), more often male (55% vs 42%, p = 0.04), had a lower prevalence of atrial fibrillation (2.0% vs 13%, p < 0.001), and a higher prevalence of diabetes (39% vs 19%, p < 0.001). MA ethnicity was independently associated with nonlobar hemorrhage (OR 2.08, 95% CI: 1.15, 3.70). MAs had over two times the odds of having small (< 30 mL) hemorrhages compared with NHWs (OR = 2.41, 95% CI: 1.31, 4.46). NHWs had higher in-hospital mortality, though this association was no longer significant after adjustment for ICH volume, location, age, and sex.

CONCLUSIONS

There are significant differences in the characteristics of ICH in MAs and NHWs, with MA patients more likely to have smaller, nonlobar hemorrhages. These differences may be used to examine the underlying pathophysiology of ICH.

Presentation of intracerebral haemorrhage in a community

BACKGROUND

Studies on intracerebral haemorrhage (ICH) from tertiary care centres may not be an accurate representation of the true spectrum of disease presentation.

OBJECTIVE

To describe the clinical and imaging presentation of ICH in a community devoid of the referral bias of an academic medical centre; and to investigate factors associated with lower Glasgow coma scale (GCS) score at presentation, as GCS is crucial to early clinical decision making.

METHODS

The study formed part of the BASIC project (Brain Attack Surveillance in Corpus Christi), a population based stroke surveillance study in a bi-ethnic Texas community. Cases of first non-traumatic ICH were identified from years 2000 to 2003, using active and passive surveillance. Clinical data were collected from medical records by trained abstractors, and all computed tomography (CT) scans were reviewed by a study physician. Multivariable linear regression was used to identify clinical and CT predictors of a lower GCS score.

RESULTS

260 cases of non-traumatic ICH were identified. Median ICH volume was 11 ml (interquartile range 3 to 36) with hydrocephalus noted in 45%. Median initial GCS score was 12.5 (7 to 15). Hydrocephalus score (p = 0.0014), ambient cistern effacement (p = 0.0002), ICH volume (p = 0.014), and female sex (p = 0.024) were independently associated with lower GCS score at presentation, adjusting for other variables.

CONCLUSIONS

ICH has a wide range of severity at presentation. Hydrocephalus is a potentially reversible cause of a lower GCS score. Since early withdrawal of care decisions are often based on initial GCS, recognition of the important influence of hydrocephalus on GCS is warranted before withdrawal of care decisions are made.

Emergency department evaluation of ischemic stroke and TIA: the BASIC Project

OBJECTIVE

To identify demographic and clinical variables of emergency department (ED) practices in a community-based acute stroke study.

METHODS

By both active and passive surveillance, the authors identified cerebrovascular disease cases in Nueces County, TX, as part of the Brain Attack Surveillance in Corpus Christi (BASIC) Project, a population-based stroke surveillance study, between January 1, 2000, and December 31, 2002. With use of multivariable logistic regression, variables independently associated with three separate outcomes were sought: hospital admission, brain imaging in the ED, and neurologist consultation in the ED. Prespecified variables included age, sex, ethnicity, insurance status, NIH Stroke Scale score, type of stroke (ischemic stroke or TIA), vascular risk factors, and symptom presentation variables. Percentage use of recombinant tissue plasminogen activator (rt-PA) was calculated.

RESULTS

A total of 941 Mexican Americans (MAs) and 855 non-Hispanic whites (NHWs) were seen for ischemic stroke (66%) or TIA (34%). Only 8% of patients received an in-person neurology consultation in the ED, and 12% did not receive any head imaging. TIA was negatively associated with neurology consultations compared with completed stroke (odds ratio [OR] 0.35 [95% CI 0.21 to 0.57]). TIA (OR 0.14 [0.10 to 0.19]) and sensory symptoms (OR 0.59 [0.44 to 0.81]) were also negatively associated with hospital admission. MAs (OR 0.58 [0.35 to 0.98]) were less likely to have neurology consultations in the ED than NHWs. Only 1.7% of patients were treated with rt-PA.

CONCLUSIONS

Neurologists are seldom involved with acute cerebrovascular care in the emergency department (ED), especially in patients with TIA. Greater neurologist involvement may improve acute stroke diagnosis and treatment efforts in the ED.

Definitive localization of isolated tracheoesophageal fistula using bronchoscopy and esophagoscopy for guide wire placement

PURPOSE

To aid in identification of isolated tracheoesophageal fistulas (TEF), many surgeons have recommended the bronchoscopic placement of a ureteric or Fogarty catheter. This method can fail because of intraoperative dislodgment of the catheter. The authors present a new technique that enables us to definitively isolate and treat all H-type fistulas.

METHODS

Six cases of isolated TEF are presented consisting of 4 H-type fistulas, a proximal pouch fistula, and a recurrent TEF. Three of the patients had undergone a total of four prior failed operations at outside institutions using attempted bronchoscopic catheter placement. On all six patients, bronchoscopy was first performed where the fistula tract was noted in the trachea and a guide wire was passed through the fistula. After orotracheal intubation, the authors performed rigid esophagoscopy; the guide wire was identified and brought out through the mouth. This created a wire loop through the fistula. With the use of x-ray we were then able to visualize the level of the fistula and determine whether a cervical or thoracic approach should be used. Identification of the fistula intraoperatively was then facilitated by traction on the loop by the anesthesiologist.

RESULTS

Five of the six TEFs were repaired with neck exploration; one required right thoracotomy. In all patients, the fistula was identified and divided. There were no recurrences or other complications.

CONCLUSION

This new technique is a simple and definitive method in identification and treatment of isolated TEF.

[Housedust mite culture medium: an alternative source for the production of allergenic extracts]

House dust mites are the most important source of allergens in the tropical environment, and aqueous whole body extracts of these organisms have wide use in the diagnosis and treatment of allergic diseases. However, it has been reported that mite excretions have a high allergenic activity. Because of this, we have evaluated spent house-dust mite culture medium as an alternative source of allergens from these organisms. We demonstrated that the extraction of allergens from this material is more efficient in alkaline solutions such as ammonium bicarbonate, and when the extraction process is extended to 48 hours. When the purification process is complemented with dialysis and ammonium sulphate precipitation, the toxicity of the extract decreases and its allergenic activity increases. The electrophoretic pattern of proteins of the spent culture medium extract showed bands that bound specific IgE antibodies, but this extract may be deficient in one of the principle allergens of mites, Der pII. The extract stimulates immediate hypersensitivity skin reactions in house-dust allergic patients, and produces RAST inhibitions with their sera. The allergenic activity of this extract is comparable to that of the 1st. International Standard for house-dust mite extracts. These results demonstrate that spent house-dust mite culture medium is an appropriate source of allergens from these organisms, and because of its low commercial value, may be an economical alternative for the production of allergenic extracts.

Biological activity of recombinant Der p 2, Der p 5 and Der p 7 allergens of the house-dust mite Dermatophagoides pteronyssinus

Der p 2, Der p 5 and Der p 7 are three allergens of the house-dust mite Dermatophagoides pteronyssinus that have been cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST). We showed that these recombinant allergens produced immediate hypersensitivity skin-test reactions in 70, 60 and 52% respectively of a group of mite-sensitive allergic patients who were strongly positive to whole mite extract (WME). Comparable positivities were found for serum levels of specific IgE antibody against these allergens, as measured by the radioallergosorbant test (RAST). Overall, for the group of allergic patients that we evaluated, the serum IgE antibody concentrations against Der p 2, 5 and 7 were calculated to represent about one third, one quarter and one fifth respectively of the levels measured against the WME. However, for some patients the activity determined against the separate allergens was far higher than that detected against the WME, thus indicating that the concentration of these can be limiting in the WME. We found no significant correlations between the RAST levels against Derp 2 and either Derp 5 or 7, and RAST-inhibition tests indicated a lack of cross-reactivity between Der p 2 and the other two allergens. In contrast, the RAST results revealed the existence of a significant immunological relationship between Der p 5 and 7. Although a certain degree of reactivity against the GST fusion partner was found in the allergic patients studied, this was not a significant influence in determining the positivity against the recombinant allergens. These results confirm the in vivo biological activity of recombinant Der p 2, 5 and 7, and indicate that whilst Der p 2 is undoubtedly a major mite allergen, both Der p 5 and 7 make important contributions toward the overall allergenic activity of house-dust mites.

Burn injury alters coronary endothelial function

This study examined the effects of burn injury on coronary endothelial function and coronary vascular reactivity. Adult rabbits were given a scald burn over 30% of the total body surface area (or sham burn for controls) and resuscitated with Ringer's lactate solution (4 ml/kg/% burn). Subgroups of burned (n = 6) and sham-burned (n = 6) animals were sacrificed at 2, 6, and 24 hr after injury; hearts were harvested and perfused. Changes in coronary perfusion pressure (CPP, mmHg) and coronary vascular resistance (CVR, mmHg/min) were determined at a constant preload and constant coronary flow rate. Changes in coronary endothelial function were determined by the ability of the endothelium to release cGMP as an indicator of nitric oxide production. Compared to values measured in sham burns, CPP and CVR progressively fell during the early postburn period but increased toward values measured in the sham burn group by 24 hr. Cyclic GMP, fmole/ml of coronary perfusate, was significantly lower in burned hearts (27 +/- 1) compared to values measured in effluents from sham burn hearts (310 +/- 40, P < 0.05). Alterations in coronary effluent cGMP levels after burn injury suggest that thermal injury disrupts coronary endothelial function, likely contributing to postburn changes in cardiac performance.

Immunochemical study of a Paracoccidioides brasiliensis polysaccharide-like antigen

The polysaccharide antigen from P. brasiliensis has been largely employed in serologic tests ,as well as in skin tests, to evaluate cellular immunity. SDS-PAGE analysis of this antigen has revealed a variability in the number of bands exhibited by isolates SN, 265, 339, 113, and 18 (7 to 16 bands). The antigens obtained from isolates 2, PTL, 192 and Adel showed two or three bands. Glycoprotein analysis demonstrated a broad region between 50 and 90 kDa. Major bands of 48 and 30 kDa were present in almost all antigens. Optimal complement fixing dilution appears to be unaffected by the number of bands presented by different antigens. The immunoblot analysis revealed that the 90 and 30 kDa bands were mainly recognized by sera from paracoccidioidomycosis patients. Bands of high molecular weight were also recognized by most of the sera studied. Sera from histoplasmosis recognized the 94 kDa band. In conclusion, although the isolates exhibit quantitative variability in the number of fractions, it is possible to use only one or two samples given the greatest frequency of reactivity is seen in the 30 and 90 kDa fractions.

Postburn cardiac contractile function and biochemical markers of postburn cardiac injury

BACKGROUND

In vivo assessment of cardiac injury and contractile deficits after thermal injury remain difficult as neurohumoral compensatory mechanisms maintain cardiac output. While measurement of creatine kinase (CK) and the isoenzyme of creatine kinase (CKMB) have been used as clinical indicators of cardiac injury, these biochemical markers are not completely specific for cardiac muscle. Cardiac protein troponin I (cTnI) is unique to the myocardium but can be detected in the systemic circulation within three to four hours after cardiac injury. The purpose of this study was to examine cardiac contractile function at several postburn intervals and to correlate the appearance of cardiac dysfunction with biochemical measures of cardiac injury (serum concentration of CK, CKMB, and cTnI).

STUDY DESIGN

New Zealand white rabbits were deeply anesthetized and a scald burn comprising 34 percent of the total body surface area (n = 36) or sham burn (n = 36) was accomplished using a template device. All burn rabbits were given lactated Ringer's solution (4 mL/kg/percent burn, Parkland formula). Blood samples were collected immediately prior to sacrifice in six animals from both burn and control groups, and animals were sacrificed either two, four, six or 24 hours after burn. Cardiac function was assessed in left ventricular preparations (Langendorff) and serum CK, CKMB, and cTnI levels were determined.

RESULTS

Cardiac dysfunction occurred at all times after burn as indicated by a lower peak systolic left ventricular pressure and +/- dP/dt maximum compared with time-matched shams and the shift of left ventricular function curves plotted for burn groups downward and to the right of those calculated for shams, p < 0.05. Left ventricular systolic dysfunction after burn correlated with a progressive rise in cTnI and CK but not CKMB.

CONCLUSIONS

The cardiospecificity of the cTnI eliminates concerns about tissue source associated with CK and CKMB and provides a biochemical measure of cardiac injury that is consistent with in vitro assessment of cardiac dysfunction.

Lack of reactivity of paracoccidioidomycosis sera in the double immunodiffusion test with the gp43 antigen: report of two cases

Sera from two patients with chronic active paracoccidioidomycosis yielded negative double immunodiffusion results with a culture filtrate antigen from Paracoccidioides brasiliensis routinely used in our laboratory. Complement fixation tests were positive for both sera using a polysaccharide-rich antigen. This study reports the results of a more extensive serological investigation of these two sera. Both a somatic antigen and a saline extract from the fungus yielded positive results in the double immunodiffusion. However, the immunodominant 43 kDa glycoprotein antigen showed negative results, although it was recognized by both sera in the Western blot assay. The value of the double immunodiffusion as a single serological test in paracoccidioidomycosis diagnosis is discussed.

Evaluation of a new hemostatic agent in experimental splenic laceration

OBJECTIVES

To compare the effectiveness of several hemostatic agents and to evaluate a new hemostatic agent (ReClot) in controlling splenic hemorrhage.

DESIGN

Rabbits were anesthetized and catheters placed. A celiotomy was performed and a splenic injury produced; hemostatic agent and compression were applied.

EXPERIMENTAL GROUPS

In group 1 (n = 8), the splenic laceration was compressed with a dry sponge and 75 g of pressure until hemorrhage ceased. In groups 2, 3, and 4 (n = 10 each), splenic injury was treated with Avitene, Collastat, and ReClot, respectively. Hemostatic agent was applied to the splenic laceration and a dry sponge and pressure were applied as described for group 1. In group 5 (n = 9), a splenic laceration was produced, ReClot applied, and aggressive fluid resuscitation was initiated; the volume of crystalloid was adjusted to maintain mean arterial pressure.

RESULTS

Application of a hemostatic agent reduced total blood loss compared with that measured in the control group, but there was no difference in blood loss among experimental groups treated with a hemostatic agent. The time required to achieve control of blood loss was less in the ReClot-treated group compared with the Avitene- and Collastat-treated groups.

CONCLUSIONS

The hemostatic agent ReClot had a significant advantage over other hemostatic agents for the time required to achieve control of splenic bleeding. Aggressive fluid resuscitation did not limit the ability of ReClot to produce hemostasis.

Paracoccidioides brasiliensis. A mycologic and immunochemical study of a sample isolated from an armadillo (Dasipus novencinctus)

A sample of P. brasiliensis isolated from the spleen and the liver of an armadillo (Dasipus novencinctus) has been analysed under a mycological and immunochemical viewpoint. The armadillo was captured in an area of Tucuruí (State of Pará, Brazil), the animal being already established as an enzootic reservoir of P. brasiliensis at that region of the country. This sample maintained in the fungal collection of the Tropical Medicine Institute of São Paulo (Brazil) numbered 135, has got all the characteristics of P. brasiliensis, with a strong antigenic power and low virulence for guinea-pigs and Wistar rats. The specific exoantigen of P. brasiliensis--the glycoprotein with a molecular weight of 43 kDa--was easily demonstrated with double immunodiffusion, immunoelectrophoresis, SDS-PAGE and immunobloting techniques.

Effect of inhibiting leukocyte integrin (CD18) and selectin (L-selectin) on susceptibility to infection with Pseudomonas aeruginosa

Leukocyte (WBC) adherence to endothelial cells has been implicated in the pathogenesis of microvascular injury. The process of leukocyte adherence is mediated by both the integrin and selectin families of molecules, and their interaction with specific endothelial ligands. Antibodies directed against the leukocyte integrin CD18 and L-selectin have been developed and functionally inhibit leukocyte adherence in models of inflammatory injury. We asked the question: Does inhibition of leukocyte adherence by administration of monoclonal antibody directed against either CD18, integrins (R15.7, R7.1) or against L-selectin (DREG 200) increase susceptibility to infection? New Zealand white rabbits were shaved and injected subcutaneously on their dorsum with Pseudomonas aeruginosa (ATCC#27853) at two sites each of 10(8) and 10(7) colony forming units. Animals were monitored with daily determination of weight, temperature, WBC counts, hematocrit, and killed at 1 week for determination of abscess formation. There were four blinded experimental groups: (1) Saline (2 mL/kg); (2) DREG 200 (2 mg/kg); (3) R7.1 (2 mg/kg); or (4) R15.7 (2 mg/kg). At the 10(7) and 10(8) injection sites the R15.7 group had an increased rate and size of abscess formation compared with controls. The R7.1 group had an increased rate at the 10(8) injection site. There was no significant difference in the percentage of the abscess formation or mean area between the controls and DREG 200-treated groups. We conclude that giving antibody to CD18 increased susceptibility to infection while giving antibody to L-selectin does not.

L-arginine improves resting cardiac transmembrane potential after burn injury

Previous studies from our laboratory have suggested that burn injury disrupts nitric oxide production and promotes a loss of cell membrane integrity. We hypothesized that administration of L-arginine, a precursor of nitric oxide (NO), would prevent postburn depolarization of the cardiac cell membrane and preserve cell membrane integrity. Third degree scald burn comprising 43% of the total body surface area was produced in rats (n = 22); sham burn controls (n = 11) were included. Burn rats were either untreated (N = 11) or given 300 mg/kg L-arginine immediately, 3, 6, and 23 h postburn. Untreated burn injury caused depolarization of the cardiac cell membrane (cardiac Em fell from 79.0 +/- 1.4 mV in shams to 67.0 +/- 1.5 mV 24 h after untreated burn, p < .05) and an increase in myocardial tissue lactate. Urine nitrate levels (assessed to provide a measure of NO production) fell after untreated burn (0.49 +/- 0.10 microM/24 h) compared with levels measured in sham burns (7.99 +/- 0.64 microM/24 h, p < .05), indicating that burn injury reduced NO production. Postburn administration of L-arginine improved cardiac Em (81.5 +/- 2.1 mV), reduced myocardial tissue lactate levels, and increased urinary nitrate levels above values measured for untreated burns. Our data indicate that L-arginine, in the absence of fluid resuscitation, provides postburn cardiac cell membrane protection, possibly due to enhanced nitric oxide production.

[Paracoccidioides brasiliensis, a new sample isolated from feces of a penguin (Pygoscelis adeliae)]

The Authors show the results obtained through the study of a Paracoccidioides strain isolated from a penguin in the Uruguaian Antartide by GEZUELE et al. (1989). From the fecal mater it was isolated a fungus which was recently considered as a new species of the genus Paracoccidioides--P. antarcticus. However, the mycological and immunochemical studies including the demonstration of the 43 kDa glycoprotein by immunodiffusion test, SDS-PAGE and immunoelectrophoresis disclosed that such strain is similar to P. brasiliensis. Other studies, based on molecular taxonomy, including karyotyping, are the only tools to confirm the possibility of such strain to be a variant of P. brasiliensis. The Authors report the epidemiological significance of that finding and suggest a review in the knowledge of the ecological "niche" of P. brasiliensis.

Allergic reactivity of children of different socioeconomic levels in tropical populations

Widely variable prevalences of allergic diseases have been reported in tropical populations, and this has been suggested to be due to effects of the nonspecific polyclonal stimulation of IgE synthesis caused by the helminthic infections that are endemic in these areas. Since 1980, we have been evaluating the allergic reactivity of different socioeconomic sectors of the population of tropical Venezuela (lat. 2-12 degrees N), and in the present study analyze the overall results obtained in the laboratory evaluation of children (5-15 years of age) belonging to these groups. Children of medium-high socioeconomic level (M-HSEL), who experience occasional helminthic infections, have moderately high total serum IgE levels, and have elevated skin test positivities and specific IgE levels against environmental allergens. Persons of low socioeconomic level, in the urban, and particularly rural situation experience frequent helminthic infection, and have highly elevated total serum IgE levels. In contrast to the M-HSEL, the majority of these children have detectable specific IgE antibody against a variety of inhalant allergens, but relatively few have high levels, and their skin test positivity is also low. In these frequently parasitized persons, evidence of saturation of mast cell Fc epsilon receptors was found by tests of passive sensitization. We propose, therefore, that helminthic parasites have a biphasic effect on allergic reactivity; occasional infections are stimulatory, via their nonspecific potentiation of IgE synthesis against environmental allergens, and frequent infections are suppressive due to the widely polyclonal stimulation that they cause, resulting in both diminished specific antibody production against any given allergen and mast cell Fc epsilon receptor saturation.

The sensitivity, specificity and efficiency values of some serological tests used in the diagnosis of paracoccidioidomycosis

This work reports on the results of double immunodiffusion (ID), counterimmunoelectrophoresis (CIE), complement fixation (CF) and indirect immunofluorescence (IIF) techniques in the serodiagnosis of paracoccidioidomycosis. The study was undertaken on four groups of individuals: 46 patients with untreated paracoccidioidomycosis, 22 patients with other deep mycoses, 30 with other infectious diseases (tuberculosis and cutaneous leishmaniasis) and 47 blood donors as negative controls. Data were obtained using Paracoccidioides brasiliensis antigens, i.e., a yeast culture filtrate for ID, CIE and CF, and a yeast cell suspension for IIF. The sensitivity, specificity and efficiency values were measured according to GALEN & GAMBINO. The gel precipitation tests (ID and CIE) showed the greatest sensitivity (91.3 and 95.6%, respectively), maximum specificity (100%) and the highest efficiency values when compared to the CF and IIF tests.

[Obtention of Histoplasma capsulatum exoantigens in neopeptone, glucose, thiamine and asparagine (NGTA) media]

The purpose of this work is obtaining exocellular antigens H and M from 4 H. capsulatum strains using NGTA medium (neopeptone, glucose, thiamine and asparagine) for periods of 1, 2 and 3 months, at 36 degrees C and continuously shaken. The exocellular antigens were evaluated by double immunodiffusion test against H. capsulatum rabbit antiserum, 7 histoplasmosis sera, 4 paracoccidioidomycosis sera and a reference antigen and antibody furnished by C.D.C. (Atlanta--USA). Except for the exocellular antigen from strain B.679 with 1 month of culture, all exocellular antigens obtained from the strains B.679, 58 and O187 showed the H and M bands. The A.811 strain demonstrated only the fraction H. All the exocellular antigens reacted positively with sera from histoplasmosis patients, except those obtained from strains 58 and B.679 with 1 month of culture. With regard to paracoccidioidomycosis patients sera, the exocellular antigens from strains 58 and O187 did not cross-react with them.

Isolation and characterization of a Paracoccidioides brasiliensis strain from a dogfood probably contaminated with soil in Uberlândia, Brazil

We report the isolation of a strain of Paracoccidioides brasiliensis from a dogfood, probably contaminated with soil, in a Brazilian city. The fungus was isolated on appropriate culture media, and when inoculated into a guinea-pig testis produced orchitis with abundant fungal elements. Histopathology of sections of the testicle showed an inflammatory reaction with P. brasiliensis inside monocytes. Immunological identification confirmed the identity of the isolate.

T lymphocytes can recognize determinants unique to neuropeptides of guinea pig myelin basic protein containing a single D-isomer amino acid substitution

The present studies were undertaken to examine how the substitution of racemized forms of selected amino acids in synthetic peptides of guinea pig myelin basic protein (GPMBP) would alter the host's immunological ability to recognize such molecules. Using peptides from the 69-84 sequence of GPMBP containing a D-serine at position 70 or 75 (69-84[D-ser70 or D-ser75]) or D-aspartate at position 82 (69-84[D-asp82]), the findings demonstrated that the position of the diastereomer substitution on these neuropeptides was critical with respect to the ability of the immune system to recognize the molecule. Thus substitution of D-asp at position 82 or D-ser at position 75 abrogated the ability of these peptides to induce experimental autoimmune encephalitis and proliferation of host T cells. In contrast, a peptide containing a D-ser70 residue was capable of inducing clinical disease in rats, as well as stimulating T lymphocytes from 69-84-(D-ser70)-injected animals. Moreover, although this D-peptide was shown to share at least some determinant(s) with the 69-84 peptide, the use of 69-84(D-ser70)-stimulated cell lines demonstrated that some epitope(s) unique to this molecule could stimulate CD4+ syngeneic T cells.

D-aspartate in human brain

The presence of the biologically uncommon D-aspartic acid (D-aspartate) in human brain white matter has been previously reported. The earlier study has now been expanded to include D/L-aspartate ratios from 67 normal brains. The data show that the D-aspartate content increases rapidly from 1 year to approximately 35 years of age, levels off in middle age, and then appears to decrease somewhat. The D-aspartate content in gray matter remains at a consistently low level (half of that found in white matter) throughout the human life span. Within the limitations of current analytical methods, there was no detectable difference in D/L-aspartate ratios in white and gray matter of brains with Alzheimer's disease and several other pathologies when compared with brains of normal subjects. However, the presence of a significant D-aspartate level in white matter during the adult life span may lead to changes in protein configuration related to dysfunctions associated with the aging brain.

D-aspartic acid in purified myelin and myelin basic protein

The presence of the biologically uncommon D-isomer of aspartic acid in the white matter of human brains has been reported previously from this laboratory (1). We now report that the level of D-aspartate in human brains is higher in purified myelin than in white matter and is even higher in the myelin basic protein fraction. There also appears to be a difference in the level of D-aspartate found in human brain as compared to bovine brain, possibly a species or age-related difference.