The role of gamma interferon in infection of susceptible mice with murine coronavirus,MHV-JHM

Summary Infection of BALB/c mice with mouse hepatitis virus, strain JHM (MHV-JHM), at any of several intervals relative to ovalbumin (OVA) administration resulted in elevated OVA-specific IgG 2 a titers. Since gamma interferon (IFN) has been implicated as an up-regulator of IgG 2 a production, attempts were made to determine whether levels of this cytokine were modified in sera of infected mice. Serum IFN- was not detected, but treatment of MHV-JHM-infected mice with monoclonal anti-IFN- antibody resulted in high mortality with decreased survival times, enhanced virus titers in liver and spleen, and more severe virus-associated pathology, compared to mock-treated, infected mice. Immunotherapy with recombinant IFN- ameliorated disease as reflected by mortality rates and virus titers in target organs.     

Attempts to culturing triatominae in the laboratory using "in vitro" feeding]

In order to simplify breeding of triatominae in the laboratory, for performing xenodiagnosis and other biologic studies, we tried to feed the insects "in vitro" with citrated or defibrinated blood from commercially abated chicken. Two types of efficacy observations were carried out with Triatoma infestans: a) analysis of the chaining of successive nymphal stages, viability of satisfactory matching, fertile oviposition and adequate reproduction; b) assessment of viability and infectivity of Trypanosoma cruzi in the insects. As a conclusion, it became evident that, despite operational easiness, the objectives were not achieved, since the classical procedure used as the control, was always superior.     

Neuropsychiatric evaluation in subjects chronically exposed to organophosphate pesticides.

Long-term exposure to low levels of organophosphate pesticides (OP) may produce neuropsychiatric symptoms. We performed clinical, neuropsychiatric, and laboratory evaluations of 37 workers involved in family agriculture of tobacco from southern Brazil who had been exposed to OP for 3 months, and in 25 of these workers, after 3 months without exposure to OP. Plasma acetylcholinesterase activity levels of all subjects were within the normal range (3.2 to 9.0 U/l) and were not different between on- and off-exposure periods (4.7 +/- 0.9 and 4.5 +/- 1.1 U/l, respectively). Clinically significant extrapyramidal symptoms were present in 12 of 25 subjects, which is unexpected in such a population. There was a significant reduction of extrapyramidal symptoms after 3 months without exposure to OP, but 10 subjects still had significant parkinsonism. Mini-mental and word span scores were within the expected range for this population and were not influenced by exposure to OP. Eighteen of the 37 subjects (48%) had current psychiatric diagnoses in the first interview (13 with generalized anxiety disorder and 8 with major depression). Among the 25 subjects who completed both evaluations, the total number of current psychiatric diagnoses, after 3 months without using OP, dropped from 24 to 13 and the number of affected individuals with any psychiatric diagnosis dropped from 11 to 7. In conclusion, this study reinforces the need for parameters other than acetylcholinesterase activity to monitor for chronic consequences of chronic low-dose OP exposure, and it suggests that subjects have not only transient motor and psychiatric consequences while exposed, but may also develop enduring extrapyramidal symptoms.     

Resolution of isoforms of mutalysin II, the metalloproteinase from bushmaster snake venom

Mutalysin II, a zinc endopeptidase possessing direct-acting fibrinolytic activity has been previously purified from bushmaster (Lachesis muta muta) snake venom. We now report a method to isolate two isoforms of natural mutalysin II (mut IIa and mut IIb) using chromatographies on Sephacryl S-200, CM Sepharose CL 6B and Sephadex G-50. The two proteins are monomeric non-glycosylated proteinases with similar molecular masses of 23 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Tryptic peptide mapping of the two native enzymes suggested a large degree of structural similarity. Both isoforms showed high similarity in all enzymatic properties using fibrinogen, fibrin and dimethylcasein as substrates. Thus, the specific fibrinolytic activity was estimated as 12±1.04 and 11.5±1.02 U/μg for mut IIa and mut IIb, respectively. The antigenic cross-reactivity of both isoforms was examined using rabbit hyperimmune serum or immunoglobulin G anti-mut IIa assays on immunodiffusion microscope slides, indirect enzyme-linked immunoabsorbent assay and western blots. From these experiments it was concluded that the two metalloproteinases mut IIa and mut IIb share identical antigenic structures. Since the stability of mutalysin II is dependent upon the presence of zinc, we examined the EDTA sensitivity of the isoforms of mutalysin II. Thus, the IC₅₀ values (concentration of EDTA to produce 50% inhibition of dimethylcasein hydrolysis) for mut IIa is 180 μM and 165 μM for mut IIb.     

Double Outlet Right Ventricle with Intact Atrial Septum and Restrictive Ventricular Septal Defect: An Analysis of Two Cases

Two cases of double outlet right ventricle with restrictive ventricular septal defect are described. This is an uncommon presentation that causes left ventricular dysfunction because of left ventricular outflow tract obstruction. The presence of an intact atrial septum leads to severe pulmonary hypertension, which tends to aggravate the right ventricular output. In the presence of a normal left ventricle, the authors suggest the possibility of enlargement of the ventricular septal defect in order to perform a biventricular repair. The association of a supramitral valve ring in both cases, and the isolation of the left subclavian artery and an aortopulmonary fenestration in one of these cases, are also discussed. In addition we explore factors that cause restrictive ventricular septal defects as well as the mechanisms that may lead to spontaneous closure of ventricular septal defect in a double outlet right ventricle.     

Intravenous Leiomyomatosis of the Uterus

Three cases of intravenous leiomyomatosis (IVL) of the uterus, a rare benign smooth-muscle tumor, are described. A preoperative diagnosis of IVL was not made in any of the patients, all of which presented with a pelvic mass with the presumptive diagnosis of leiomyoma. Surgical exploration confirmed the presence of uterine mass and two of the three cases showed extra-uterine extension into the ovarian or uterine veins. Histological examination demonstrated a fascicular pattern of bland spindle-shaped smooth-muscle cells, which extended to veins inside the myometrium or to extrauterine veins. This was confirmed by immunohistochemical stain for desmin and factor VIII. Despite their histological benignity, these lesions have a tendency to metastasize and are closely related to the conditions called “benign metastasizing leiomyoma” and “intracaval mass and cardiac extension”. The primary treatment of IVL is hysterectomy and excision of any extrauterine tumor, when technically feasible. Anti-estrogenic therapy has been suggested as potentially useful in controlling of unresectable tumor. According to the literature, the follow-up must be long and periodic postoperative ultrasonic or magnetic nuclear resonance imaging studies may be useful in detecting growth of residual intravascular tumor.     

Guanosine and GMP prevent seizures induced by quinolinic acid in mice

In the mammalian CNS, glutamate and GABA are the principal neurotransmitters mediating excitatory and inhibitory synaptic events, respectively, and have been implicated in the neurobiology of seizures. Guanine-based purines, including the nucleoside guanosine and the nucleotide GMP, have been shown to antagonize glutamatergic activity at the receptor level and the other purine nucleoside adenosine is a well-known modulator of seizure threshold. In the present study we investigated the anticonvulsant effect of i. p. guanosine and GMP against seizures induced by the glutamate agonist quinolinic acid (QA) or the GABA(A) antagonist picrotoxin in mice. Animals were pretreated with an i.p. injection of saline, guanosine or GMP 30 min before either an i.c.v. injection of 4 microliter QA (36.8 nmol) or a subcutaneous injection of picrotoxin (3.2 mg/kg). All animals pretreated with vehicle followed by QA or picrotoxin presented seizures, which were completely prevented by the NMDA antagonist MK-801 and the GABA agonist phenobarbital, respectively. Guanosine and GMP dose-dependently protected against QA-induced seizures, up to 70 and 80% at 7.5 mg/kg, with ED(50)=2. 6+/-0.4 and 1.7+/-0.6 mg/kg, respectively. Conversely, neither guanosine, GMP nor MK-801 affected picrotoxin-induced seizures, indicating some degree of specificity towards the glutamatergic system. This study suggests anticonvulsant properties of i.p. guanosine and GMP, which may be related with antagonism of glutamate receptors.     

Optimal management of complicated empyema

BACKGROUND: Despite continued improvement in medical therapy, empyema remains a challenging problem for the surgeon. Multiple treatment options are available; however, the optimal therapeutic management has not been elucidated. METHODS: A retrospective review was performed of all adult patients admitted to Denver Health Medical Center between January 1, 1993, and December 31, 1998, with the diagnosis of empyema. Data tabulated included patient demographics, presentation, chest computed tomography (CT) findings, treatment, and outcome. RESULTS: Empyema was diagnosed in 58 patients, 45 cases of which were multiloculated at the time of presentation. Empyema was secondary to pneumonia is 41 patients and posttraumatic in 15. In addition to antibiotic therapy, initial treatment included chest tube drainage alone (n = 6), chest tube drainage with primary operation (n = 19), and chest tube drainage with intrapleural fibrinolytic therapy (n = 33). In 15 patients (45%), fibrinolytic therapy failed. Initial chest CT revealed a pleural peel in 5 patients treated with fibrinolytics and all failed. Multiloculation, however, was not a factor in failure of fibrinolysis. Moreover, chest CT missed the presence of a pleural peel in 17 of 31 patients documented to have a significant peel at the time of thoracotomy. CONCLUSION: Multiple therapeutic options are available for the management of empyema. Multiloculation is not a contraindication to an initial trial of chest tube drainage or fibrinolytic therapy. In contrast, CT evidence of a pleural peel uniformly predicted failure of nonoperative treatment.     

The use of the female condom by women in Brazil participating in HIV prevention education sessions.

OBJECTIVES: To study HIV-positive women and women at risk of becoming infected with HIV who attended HIV prevention education group sessions at a university hospital in Brazil and to compare the use of the female condom and the male condom by these two groups of women. METHODS: The study subjects were 165 women participating in HIV prevention education group sessions at the Medical School Hospital of Ribeir?o Preto of the University of S?o Paulo, in the city of Ribeir?o Preto, S?o Paulo, Brazil. Women could be enrolled in the study from August 2000 to June 2001, and the follow-up observation time period was from August 2000 to July 2001. Male condoms and female condoms were freely distributed to all the participants at the end of each educational session and also at the end of each follow-up visit that the participants made. Each woman took part in an initial interview and was asked to return monthly. At each follow-up visit an additional short interview was carried out in order to investigate use of the male condom and of the female condom. Variables that were examined for the study included age, education, ethnic group, marital or relationship status, number of children, the women's use of male condoms and female condoms, commercial sex (whether the women had ever had sex in exchange for money, gifts, or favors), and previous knowledge of the female condom. RESULTS: The 165 women studied fell into the following three categories: 132 of them (80.0%) were HIV-positive, 26 of them (15.8%) had a sexually transmitted disease (STD) other than HIV and did not have an HIV-positive partner, and 7 of them (4.2%) had an HIV-positive partner but did not have HIV or any other STD. The women ranged in age from 15 to 64 years, with a mean of 30.3 years. Of the women in the study, 69.7% of them were married or were cohabitating, and 90.9% of them had a sexual partner. Just over two-thirds of the women had seven years of formal schooling or less. Out of 163 women, a total of 31 of them (19.0%) had never used the male condom with a partner, and 49 of the 163 (30.1%) had not used a male condom at the time of the last sexual intercourse. Out of the 165 women, 74 of them (44.8%) returned for at least one follow-up visit. Of these 74 women, 58 of them (78.3%) reported using the female condom between the initial interview and the first follow-up visit. The majority of the 74 women who returned for a visit liked using the female condom, and the women reported that their partners also generally accepted the female condom. In comparison to women at risk of HIV, HIV-positive women were more likely to have used the male condom with a partner before the initial interview. Women who continued returning over a longer follow-up period were more likely to have used the female condom at the time of the last sexual intercourse. No association was found between female condom use at the time of last sexual intercourse and the woman's HIV infection status. CONCLUSIONS: In comparison to the women at risk of HIV, the HIV-positive women in our study were more likely to use male condoms with their partners, to return for follow-up visits, and to have a longer follow-up period. The acceptance of the female condom among the HIV-positive women in this study, as reported at their first follow-up visit, appears to be similar to the acceptance of the female condom among women in general in Brazil.