Rescue of a synthetic chloramphenicol acetyltransferase RNA into influenza virus-like particles obtained from recombinant plasmids

We have shown previously that COS-1 cells infected with a vaccinia virus recombinant (vTF7-3) which expresses the T7 RNA polymerase gene and then transfected with four pGEM-derived plasmids encoding the influenza A virus core proteins (nucleoprotein, PB1, PB2, and PA polypeptides) can express a synthetic influenza virus-like chloramphenicol [correction of chloramphenical] acetyltransferase (CAT) RNA (I. Mena, S. de la Luna, C. Albo, J. Martín, A. Nieto, J. Ortín, and A. Portela, J. Gen. Virol. 75:2109-2114, 1994). Here we demonstrate that by supplying the vTF7-3-infected cells with plasmids containing cDNAs of all 10 influenza virus-encoded proteins, the transfected CAT RNA can be expressed and rescued into particles that are budded into the supernatant fluids. The released particles can transfer the enclosed CAT RNA to MDCK cultures and resemble true influenza virions in that they require trypsin treatment to deliver the RNA to fresh cells and are neutralized by a monoclonal antibody specific for the influenza A virus hemagglutinin. Moreover, analysis by electron microscopy showed that the culture medium harvested from the transfected cells contained vesicles that could be labeled with an anti-HA monoclonal antibody and that were similar in size and morphology to authentic influenza virus particles. It is also shown that detection of recombinant particles capable of transmitting the CAT RNA does not require expression of the influenza virus nonstructural protein NS1. All of these data indicate that influenza virus-like particles enclosing a synthetic virus-like RNA can be assembled in cells expressing all viral structural components from recombinant plasmids.

Effect of management and inherent factors on birth seropositivity and seroconversion to Babesia bovis in calves in Costa Rica

The relationship between calf characteristics, farm management, seropositivity, and age at seroconversion to Babesia bovis was assessed. A total of 3624 samples obtained from 494 animals on 11 farms was analyzed by an indirect ELISA assay, and individual results classified as positive or negative. The animals were sampled from birth to weaning, beginning in April 1990 and ending in April 1992. We found 59.1% (n = 467) of seropositive neonatal calves (mean age 4.4 days). Using a logistic binomial regression model as the analytical method for predicting the likelihood of calf seropositivity, we found that the following factors were related to seroconversion at birth: time to colostrum consumption, place of birth, calving history, parity (number of lactations), and ecological life zone. To analyze the effect of management factors on time to seroconversion, we used the Proportional Hazards method. In this model the pattern of seroconversion was different for the type of production system. Calves from dual-purpose farms seroconverted earlier than calves from cow-calf farms.

Epizootiologic instability of bovine populations against Babesia bovis (Piroplasmida:Babesiidae) in the region of Poas, Costa Rica

In Poás (Costa Rica), more than 78% of the cattle population is susceptible to Babesia bovis (Babes, 1888) which indicates that care should be taken during animal movement to avoid tick exposure. Seroprevalence is less than 22%; the frequency distribution of antibody titers is presented. Significant differences (p < 0.05) were observed in the distribution of seropositive animals between ecological zones. Lower mountain rain forest and lower mountain wet forest presented higher risk for seropositivity. Based on the serological characteristics of the herds and the frequency of clinical cases, it is suggested that the cattle situation in the area is epidemiologically unstable for B. bovis.

Entamoeba histolytica: involvement of pp125FAK in collagen-induced signal transduction

The interaction of Entamoeba histolytica trophozoites with collagen involves cell adherence, formation, and release of electron dense granules (EDGs) containing collagenase activity leading to the degradation of the bound protein. The binding is thought to be mediated by an "integrin-like" collagen receptor. Since the signal transduction mechanisms triggered by the collagen-trophozoite interaction are unknown, but clearly involve cytoskeletal organization, we decided to explore the role of protein tyrosine phosphorylation in this process. Collagen induces a time-dependent increase in the phosphorylation of several polypeptides migrating around 67 and 110 kDa. One polypeptide of the high-molecular-weight component was identified as a 125-kDa protein with very similar epitopes to the focal treatment was a 42-kDa polypeptide related to the mitogen activated protein kinase (MAPK) family. Our results suggest that tyrosine phosphorylation is involved in collagen signaling in amoebas and that pp125FAK and p42MAPK homologs may play an active role in turning on the genetic program that enables the parasite to invade its host.

Correspondence between radioactive and functional methods in the quality control of DNA restriction and modifying enzymes

We evaluated the use of two radiolabeled lambda DNA/Hpa II substrates to detect 5'-->3', 3'-->5' single and double stranded DNA dependent exonuclease and phosphatase activities found as contaminants in restriction and modifying enzyme preparations. Looking for the meaning of the radioactive assays results in a real cloning experience, we performed a cloning simulation assay using the same conditions established for the radioactive assay (enzyme units and pmols of DNA ends). As a result, we found that for degradation percentages of the radioactive DNA substrate per enzyme unit below 0.5, the false positives in the cloning stimulation assay were less than 5%. This conditions could ensure a good performance of the enzyme preparations for cloning experiments. Finally, we described the use of the radiolabeled [gamma 33P] ATP lambda Hpa II DNA substrate to detect 5'-->3' single stranded DNA dependent exonuclease and phosphatase contaminating activities in some critical steps of the purification process of the restriction enzyme Kpn I.

Morphometric Study of Fetal Brain Transplants in the Insular Cortex and NGF Effects on Neuronal and Glial Development

Homotopic grafts supplemented with nerve growth factor (NGF) speed the recovery from learning deficits observed following electrolytic lesions of the insular cortex in rats. NGF also reduces the time in which the activity of choline acetyltransferase (ChAT) is first detected inside the graft by histochemical techniques. It is not known whether this behavioral and biochemical recovery correlates with an advanced maturation of the cellular elements within the graft, presumably induced by NGF. To investigate the degree of maturation of neurons, glial cells and blood vessels in NGF-supplemented grafts, adult rats were lesioned electrolytically in the insular cortex, and homotopic embryonic grafts (E16) with or without NGF supplementation were transplanted into the lesion. Fifteen days post grafting, the rats were perfused and the brains stained using silver impregnation techniques. Our results showed that neuronal maturation, as evaluated through several morphometric parameters, was advanced in NGF-supplemented grafts when compared with other experimental groups. Furthermore, grafts supplemented with NGF also showed significant increases in the number of neurons, oligodendrocytes, astrocytes and blood vessels. These observations indicated that the addition of NGF to insular cortex grafts promoted the maturation of neuronal and glial elements within the graft. They also support the possibility that the advanced morphological maturation of insular cortex grafts supplemented with NGF underlies the accelerated functional and biochemical recovery of animals with lesions of the insular cortex.

Studies of the specificities of IgE antibodies found in sera from subjects with allergic reactions to penicillins

Penicillins are immunogenic when administered to humans and in some instances they can also be allergenic, inducing specific IgE antibodies. Whilst the major haptenic group, the penicilloyl, is well characterised, less is known about the relative importance of the different parts of the structure for antibody binding and how this can influence the specificity of patients response. In order to investigate this further, sera from subjects who had suffered an IgE-mediated reaction to penicillins were studied using the radioallergosorbent test (RAST) and RAST inhibition. The assays employed reagents related to the penicillins causing the reaction. Using 173 sera, positive RAST results were only found with reagents based on benzyl penicillin (BP) and amoxicillin (AX). Fifty-three positive sera were selected for further studies and categorized into three groups: (A) sera only RAST positive to AX, (B) sera only positive to BP and (C) sera positive to both penicillins. RAST inhibition studies were then carried out using monomeric penicilloyl conjugates and compounds representing parts of the penicilloyl structures of BP and AX. For all three groups, monomeric penicilloyl conjugates were the most efficient inhibitors but there were differences for the other compounds. Group A sera were also inhibited by the side chain amoxicillin, whereas group B sera were poorly inhibited by all other inhibitors. Group C sera showed two patterns of inhibition, both consistent with their more cross-reactive profile.

[Histiocytic lymphoma and pulmonary fibrosis in a female patient with essential thrombocythemia]

The case of a patient with the diagnosis of essential thrombocythemia is presented. Following treatment with melphalan during three years the patient presented clinical and radiologic data of pulmonary fibrosis. Thoracotomy with lung biopsy histologically proving fibrosis was performed. The patient developed a true histiocytic lymphoma afterwards. The rarity of pulmonary fibrosis induced by melphalan and the exceptional association of essential thrombocythemia and histiocytic lymphoma is emphasized. The characteristics of the latter disease, diagnostic difficulties and possible treatment are commented upon.

Trichinella strain, pig race and other parasitic infections as factors in the reliability of ELISA for the detection of swine trichinellosis

An enzyme-linked immunosorbent assay (ELISA) using crude worm extracts (CWE) and mixtures of these as antigens of five Spanish isolates (P, C, B1, B2 and W) was developed for detecting homologous and heterologous experimental infections with these isolates between-14 and 82 days post-infection (p.i.) in white and Iberian pigs. A total of 243 pigs (Iberian or cross-bred with this race) with numerous parasitic infections were also screened for the presence of antibodies to a mixture of CWE of C, B1 and B2 isolate. The test showed a specificity of 93.1-98.9% depending on the cut-off values and a maximum sensitivity of 92.8-100% between days 34 and 82 p.i. A low grade of infectivity was shown in the T3 isolates compared to the T1 isolates (P, C, B1 and B2) but high cross-reactions were observed between all the isolates with minor differences between P and W isolates. The highest antibody response was found in P infections and the lowest in pigs infected with the W isolate. A clear association between the presence of several parasitic infections and false positive reactions was not found, but an important relation was shown between high background levels and the Iberian race in experimentally and conventionally raised pigs.

[An experimental evaluation of a splenic autograft in the greater omentum]

This report comprises a study of splenic autotransplantation in omental pouches in rats. Twenty six rats were operated. The spleen (50%) was transplanted after splenectomy in four different fragments. The animals were re-explored after periods between 3 and 5 1/2 months and the splenic implants retrieved for histological examination as well as size and weight evolution. In 25/26 animals a viable spleen was identified. The mean weight of the retrieved spleen fragments was 150 mg versus 525 mg weight of the implanted materials. In no case there was an increase in size of the implanted fragments. Fifty-two of the 104 implanted fragments were retrieved with weight increase in 8.65% of them.

[A solitary intracardiac metastasis in the left atrium from a pulmonary carcinoma]

Cardiac metastases are the most common cause of neoplastic disease of the heart. Usually the metastases involve the pericardium and/or myocardium but rarely they form intracavitary masses. We report a patient with a lung cancer and solitary left atrial intracardiac metastases. General features of cardiac metastases and the differential diagnosis of left intra-atrial masses are discussed.

Agranulocytosis associated with aprindine and other antiarrhythmic drugs: an epidemiological approach

The risk of agranulocytosis associated with anti-arrhythmic drugs has been assessed by studying previous drug exposure of all cases collected through a multicentre surveillance network in a defined geographical area during the period 1980-1988. One hundred and eighty-one patients with agranulocytosis (less than 500 granulocytes mm-3 at least in two different blood counts) were interviewed with a structured questionnaire. Eight cases attributable to anti-arrhythmic drugs were identified, all of them related to aprindine. Data on the consumption of several anti-arrhythmic drugs were identified, all of them related to aprindine. Data on the consumption of several anti-arrhythmic drugs (amiodarone, aprindine, quinidine, propafenone) were obtained in order to estimate the risk of agranulocytosis related with the previous use of these drugs. A relevant risk was identified only for aprindine, of the order of two cases per 1000 patient-years. Our data suggest that the risk of agranulocytosis associated with aprindine is lower than previously found.

[Variability of anthropometric parameters]

Presentation of a comparative study of four ideal weight tables applied to the same population, in order to evaluate the differences or similarities between the same. Significant differences (p<0.001) were found between the four tables studied (WHO, USA, Barcelona, Tenerife) when classifying a patient into one of the three groups defined (malnutrition, normal and obese). The maximum differences found were between the Barcelona and Tenerife tables, which classified 13,7% and 24.05% respectively as cases of malnutrition and 35.9% and 16.89% respectively as obese.

[Milker's nodes: transmission by fomites and virological identification]

We report a case of milker's nodules in a male who was not a professional cattle raiser with indirect and accidental transmission by fomites. A parapoxvirus was demonstrated from cutaneous lesions by electron microscopy with negative stain.

[Incidence of malnutrition in a surgery department]

Presentation of a description of the initial results obtained in nutritional evaluation of patients admitted for elective surgery during a 6-month period. A total of 212 patients were studied, recording malnutrition in 25%. This was severe in half of the cases. As a result of the malnutrition, a significant reduction was observed in the number of positive responses to the Multitest and the total count of lymphocytes.

Increased frequency of HLA-DR3 and complotype SC01 in Mexican mestizo patients with amoebic abscess of the liver

Our preliminary study (31 patients) of HLA frequencies and amoebic abscess of the liver (AAL) in Mexican mestizos was extended to include 110 patients with this condition. The previously found increase in HLA-B16 was not confirmed, but the frequency of HLA-DR3 was again found significantly increased in patients with AAL when compared to the normal, ethnically matched control population, both in its isolated (35.5% vs 12.7%) and in the HLA-A2, DR3 haplotypic version (20.9% vs 4.5%). Moreover, seven of the 17 HLA specificities that were found to be individually different at P (yet not at PC) level in patients with AAL when compared to the control population, were actually HLA-DR3 containing haplotypes. HLA-DR3 may thus encode a risk factor(s) for AAL, at least in the Mexican mestizo population. Furthermore a significant increase in the complotype SC01 and its haplotypic version SC01, DR4 were identified in 45 non selected patients with AAL when compared to normal controls (31.1% vs 6.7% and 17.8% vs 0% respectively). Even though a relationship between allelic forms of complement components and their function has not been fully established, this complotype could represent a risk factor as well, since complement appears to play a role in host defence against amoebic invasion. Finally, no extended haplotype preference was found in these AAL patients.

Long term active psychiatric illness in a Canadian urban region

The authors of this study examine the demographic and clinical characteristics of hospitalized long-term active psychiatric patients in a metropolitan Canadian region. Their characteristics are compared to other hospitalized patients. Problems inherent in using a cross sectional methodology are reviewed. It was expected that this study's findings will help in identifying the needs of the long-term patients in planning appropriate resources and maintaining them in the community.

Surgical treatment of thoracic hydatidosis. A review of 100 cases

Hydatid cystic disease continues to hold an important place in chest disease in our country. The authors review their experience from 1977 to 1987 of 100 patients who underwent surgery for pulmonary hydatidosis. Mean age was 36.21 years. Fifty-nine cases were ruptured cysts (RC) and 41 were unruptured cysts (UC). The diagnosis was based on epidemiological, radiological and mainly serological and endoscopic criteria. The indirect haemagglutination test was positive in 100% of RC and 80% of UC, while 70.2% of the patients who underwent fiberoptic bronchoscopy showed pathological changes. The most commonly used surgical procedure in UC was open subtotal cystopericystectomy (89.09%), while wedge resection (41.81%) was the most commonly used technique for the RC. There were no operative deaths and no recurrences were observed for a mean follow-up of 5.4 years. The indications for adjuvant chemotherapy with mebendazole are presented.

[Nosocomial infections at the University Hospital of Caracas]

Over a period of one year at the University Hospital of Caracas, a program of epidemiological surveillance was carried out on nosocomial infections. A total of 1556 cases were identified in 913 hospitalized patients. The incidence of nosocomial infections was 74 cases per 1000 hospital discharges. Cutaneous, surgical wound, lower respiratory and urinary tract infections were the most frequently identified. The Intensive Care Unit, the Neonatal Pediatric Service and the three Medicine Services recorded more than 50% of the cases. Pseudomonas aeruginosa was the most frequently isolated microorganism, followed by Escherichia coli and by Staphylococcus aureus. Most of the isolated agents were Gram negative bacteria, which present serious problems of resistance to the antimicrobics, particularly Pseudomonas aeruginosa and Acinetobacter calcoaceticus var anitratus.

A study of the drop-outs in psychopharmacological research with bulimics

Given the high drop-out rates frequently noted in drug trials with bulimic subjects, we have attempted to correlate drop-out status with a greater level of psychopathology as measured by a thorough standardized psychological assessment battery (NIMH-DIS, EDI, POMS and SCL-90). Despite a trend toward higher scores on the Paranoid Ideation Subscale of the SCL-90 among drop-outs compared to completers, there were no significant differences found between the two groups participating in a fifteen week double blind crossover study on the effectiveness of desipramine in bulimia.

Repeated users of a psychiatric emergency service in a Canadian general hospital

The authors of this study examine the demographic and clinical characteristics of repeated users of psychiatric emergency room services in a general hospital. 37.8% of all the patients (913) seen during one year had one or more visits to the emergency room in the six months preceding the index emergency room consultation. Repeaters were more likely than nonrepeaters to be unmarried, self referred and with a history of previous psychiatric treatment for a chronic psychiatric disorder. Factors affecting frequency of use of psychiatric emergency room services among different diagnostic groups were also studied. These results demonstrated the heterogeneity of the needs of the diverse diagnostic groups who over-utilize costly emergency room services. Our findings showed that in a country with universal health insurance, psychiatric emergency services also tend to reflect the gaps in the delivery of health services in the hospital and the community.

Suicidal behavior in the emergency room part 1: assessment of risk

Emergency physicians have a significant responsibility in the recognition, management and prevention of suicide behavior. A comprehensive clinical assessment should include a systematic review of high risk factors. Five important aspects associated with high risk factors are reviewed in this paper: the patient's suicidal intention; the lethality of the attempt; psychiatric diagnosis; demographic and clinical characteristics, and attitudes toward the suicidal attempt, significant others and health care providers.

Suicidal behavior in the emergency room part 2: treatment and disposition

Emergency physicians have a significant responsibility in recognizing, managing and preventing suicidal behavior. This paper proposes a theoretical model for disposition of patients with suicidal ideas and behavior. This model is based on five well documented predictors of suicide: intention and lethality of the suicide attempt, psychiatric diagnosis, demographic and clinical factors, attitude towards the attempt and support system. Treatment recommendations are based on initial assessment of these factors. Inpatients must be carefully supervised; the commonest forms of suicide in hospital are hanging and jumping from heights. Treatment plans should be implemented immediately. Since compliance with follow-up is very low in these patients, outpatient treatment should be implemented with an outreach program and integrated with community psychiatric and mental health services.

Effect of diet on chemical composition of rabbits slaughtered at fixed body weights

Four hundred and thirty-two Spanish Giant rabbits were fed 12 diets of variable energy to protein ratio [kcal digestible energy (DE)/g digestible crude protein (DCP)] from weaning to slaughter, both at different ages and weights. Body composition analysis for various chemical components indicated that body weight accounted for the greatest part of the variation in these constituents. Sex influenced only the N content (P less than .05). Dietary E/P accounted for greater variability in body composition than crude protein or crude fiber content of the diet. High dietary E/P increased (P less than .001) the proportion of body fat and reduced the proportion of body protein. This effect was made more obvious by adjustment to equal rate of weight gain and it showed that there may be a greater influence of dietary E/P on body composition than previously recognized.

Liver storage iron in normal population of Cuba

One hundred sixty-one liver specimens from subjects who died acute traumatic deaths were studied. Of these, 127 came from male subjects and 34 from female subjects. The liver storage iron values of subjects in the persent study dying acutely from traumas and the differences found are in agreement with those expected according to the iron physiological needs and the prevalence of anemia reported by this cause in the world. This substantiates that the study of nonheme iron contents in subjects who died acute traumatic deaths is a good method for assessing iron nutritional status in a population. It is interesting to note the significant increase of hepatic storage iron found in men 61 to 70 years old, although it would be important to increase the number of cases to obtain more representative data. Liver storage iron in the Cuban population is not essentially different from that reported in the United States, Sweden, and Australia and the deficiency percentage is one of the lowest in Latin America.