Leptolegnia chapmanii (Straminipila: Peronosporomycetes) as a future biorational tool for the control of Aedes aegypti (L.).

The aim of the present review is to summarize the current knowledge about Leptolegnia chapmanii as a pathogen of mosquito larvae. To this end, we present data on its identification, distribution, host range and effects on non-target organisms, effects of environmental factors, in vitro growth, release and persistence in anthropic environments, and effect combined with other insecticides. The data presented allow confirming its potential as a biocontrol agent.

New insights into the infection of the American cockroach Periplaneta americana nymphs with Metarhizium anisopliae s.l. (Ascomycota: Hypocreales).

AIMS: To study the marked resistance of Periplaneta americana to entomopathogenic Metarhizium anisopliae. METHODS AND RESULTS: The low susceptibility of 4th instar nymphs applied topically with conidia seemed to be related to an active removal of conidia by the cockroach and to a disabled or retarded germination and subsequent development of conidia on the cuticle (up to 80% germination in the next 7 days after application). Inhibitions or delays of germination were related to the composition of the epicuticular fatty acids (30·1% w/w oleic, 28·3% w/w linoleic, 24·5% w/w palmitic and 11·7% w/w stearic acid) reported here. Propagules invading the nymphs through the cuticle took at least 3 days to reach the haemocoel, and no propagules were found after day 8 post-treatment. Strain IP 46 infected >50% of nymphs treated with doses ≥2 × 104  hyphal bodies (HB) nymph-1 and reduced the survival of nymphs ≤50%. Most nymphs (>70%) survived after injection of 6 × 103 and 2 × 103  HB nymph-1 . CONCLUSIONS: Findings emphasize a distinct resistance of nymphs of the American cockroach to infections by M. anisopliae. SIGNIFICANCE AND IMPACT OF THE STUDY: Our findings provide support for the development of biological control of this synanthropic cockroach pest.

Prevalence of entomophthoralean fungi (Entomophthoromycota) of aphids (Hemiptera: Aphididae) on solanaceous crops in Argentina.

Solanum melongena L. and Capsicum annuum L. were sampled in Argentina to determine the prevalence of fungal diseased aphids. The pathogens identified were Pandora neoaphidis (Remaudière & Hennebert) Humber and Zoophthora radicans (Brefeld) Batko (Entomophthorales: Entomophthoraceae) on aphids from eggplants; and P. neoaphidis and Entomophthora planchoniana Cornu (Entomophthorales: Entomophthoraceae) on aphids from peppers. The highest fungal prevalence was 45.5% (n=2296) and 98.1% (n=3212) from aphids on eggplants and peppers, respectively. In both crops, significant differences were found on number of infected aphids among developmental stages. P.neoaphidis and E. planchoniana caused epizootics in M. persicae.

[Reference values for lead in blood in urban population in southern Brazil]. / Valores de referência para plumbemia em uma população urbana do Sul do Brasil.

OBJECTIVE: To describe the reference values for lead in blood in an urban population in the city of Londrina, in the state of Paraná, Brazil. MATERIALS AND METHODS: The reference population was composed of 520 adult volunteers who were assessed from November 1994 to December 1996. Exclusion criteria were: occupational exposure to lead, exposure through personal habits or practices, smoking more than 10 cigarettes per day, and living near industrial plants or other places that use lead in their production processes. Also excluded were individuals with abnormal clinical or laboratory results or with chronic diseases or cardiovascular disorders. Lead blood levels were determined using air-acetylene flame atomic absorption spectrophotometry. The detectable limit was 1.23 micrograms/dL. After the analyses of lead in blood, the following values were determined: minimum value, first quartile, median, third quartile, and maximum value; geometric mean; 95% confidence interval; experimental interval; and reference value. RESULTS: The reference values for lead in blood ranged from 1.20 micrograms/dL to 13.72 micrograms/dL. The geometric mean was 5.5 micrograms/dL. CONCLUSIONS: In general, the values found in this study are lower than those that have been reported for other countries. Additional data should be gathered from Brazilian populations living in more-industrialized areas.

Cross-reactive antigens of Haemonchus contortus adult worms in Teladorsagia circumcincta infected goats.

The adult Haemonchus contortus somatic antigens responsible for cross-reactivity have been analysed using serum samples from goat kids infected and reinfected with Teladorsagia circumcincta. Goat kids infected with T. circumcincta had similar serum ELISA values against somatic antigens of H. contortus as goats infected with H. contortus itself. Immunoblotting confirmed this extensive cross-reactivity particularly in the molecular weight range 105-29 kDa. However, peptides with high (195, 152 and 119 kDa) or low (23 kDa) molecular weight were only faintly recognized by heterologous sera.

Opiate agonist-induced changes in behavioral sensitivity to clonidine are observed in perinatally malnourished rats exposed to chronic stress.

Sensitivity of alpha2-adrenoceptors following repeated immobilization sessions plus morphine (MOR) or beta-endorphin (BETA) was assayed by examining clonidine (CLO)-induced hypoactivity in adult malnourished rats at perinatal age. As previously described, chronic restraint did not attenuate the hypoactivity elicited by CLO in malnourished rats, although chronic restraint did have such an effect on motor activity in control animals. MOR and BETA administration prior to each restraint session induced subsensitivity of alpha2-adrenoceptors in malnourished rats as determined by a blunted response to clonidine challenge. An injection of naloxone (NAL) prior to BETA before each stress session fully antagonized the subsensitivity to clonidine observed in malnourished animals. A possible deficiency in the functional role of the opiate system in the process of adaptation to chronic stress in perinatal malnourished rats is suggested.

Analgesic response to stress is reduced in perinatally undernourished rats.

Stress-induced analgesia was evaluated in adult rats submitted early in life to a protein deprivation schedule. Rats were undernourished with a hypoproteic diet containing 80 g casein/kg diet from d 14 of gestation until 50 days of age. Rats were thereafter fed a balanced nonpurified diet until 140 days of age, when they were exposed to two stressors: forced swimming and acute restraint, after which the analgesic response was evaluated. In addition, the analgesic response induced by different morphine doses was determined in another group of rats. Basal latency was not different in deprived and control rats. Undernourished rats presented a significantly lower analgesic response in both stress situations. However, when the analgesic response induced by different morphine doses (1, 2, 4 and 8 mg/kg, s.c.) was assessed, a significantly higher response occurred in undernourished rats compared to control rats. This lower stress-induced analgesia in undernourished rats may account for the behavioral alterations attributed to early undernutrition.

Abomasal nematodes in goats from the subtropical island of Grand Canary (Spain).

The prevalence of gastric nematodes in 151 goats on Grand Canary Island is around 56%, with a mean burden of 691 worms/animal. No significant differences of prevalence and intensity were found between the four isoclimatic areas of the island [dry-desert (DD); dry-steppe (DS); temperate-mild (TM); temperate-cold (TC)]. Five nematode species were identified, the most commonly-occurring being Teladorsagia circumcincta (observed in 65.8% of parasitized animals) and Trichostrongylus axei (51.9%). The distribution of the two species showed opposing trends: T circumcincta was more prevalent in the coastal areas (DD), diminishing in frequency closer to the centre of the island (TC), while the reverse was true of T axei. The other species identified were Haemonchus contortus, T trifurcata and Camelostrongylus mentulatus; their ranges were restricted to certain areas (H contortus in DS and TM; T trifurcata in DD, DS and TM; and C mentulatus in DD). To analyse the parasite association under natural conditions of an unusual nematode in goats, C mentulatus, with the usual parasites a principal component analysis (PCA) was used to assess the overall behaviour of the nematode community and to examine the Euclidean distances of the parasite associations. The mean Euclidean distances obtained for C mentulatus showed a tendency to a positive association which has also been observed for the other abomasal nematodes.

[Reference values for lead levels in blood for the urban population]. / Valores de referência para plumbemia em população urbana.

INTRODUCTION: The lead reference values for blood used in Brazil come from studies conducted in other countries, where socioeconomic, clinical, nutritional and occupational conditions are significantly different. In order to guarantee an accurate biomonitoring of the population which is occupationally exposed to lead, a major health concern of the studied community, reference values for individuals who are not occupationally exposed and who live in the southern region of the city were established. MATERIAL AND METHOD: The sample was composed of 206 subjects of at least 15 years of age. Various strategies were employed to assure good-quality sampling. Subjects who presented values outside clinical or laboratory norms were excluded, as well as those whose specific activities might interfere with the results. RESULTS: Lead reference values for blood were found to be from 2.40 to 16.6 micrograms.dL-1, obtained by the interval x +/- 2s (where x is the mean and s is the standard deviation form observed values) and the median was 7.9 micrograms.dL-1.

Immunohistochemical detection of Dirofilaria immitis using a rabbit polyclonal anti-serum against adult somatic antigens and excretory-secretory products.

An immunohistochemical study on tissue sections of kidney, lung, liver and spleen from six dogs naturally infected by Dirofilaria immitis was carried out, using a rabbit polyclonal anti-serum against somatic antigen (SA) of adult worms, excretory-secretory products (ES) of adult worms and fraction C3 of complement (Dog C3). Positive immunoreactions were observed on circulating microfilariae when anti-SA and anti-ES were used, but no differences were noted between the two anti-sera. No antigen deposits were observed when the three anti-sera (anti-SA, anti-ES or anti-C3) were employed as primary antibody. In two cases of human filariosis (by Loa loa and Mansonella streptocerca) no positive immunoreactions were observed.

Predictive value of palpation per rectum for detection of the CL in Zebu cattle as evaluated by progesterone concentrations and ultrasonography.

The main objective of this study was to calculate the predictive value of the positive and negative diagnosis of the presence of a corpus luteum by palpation per rectum in Zebu cattle. Gyr breed (n = 16) heifers were palpated by a veterinarian every 3 d during March and April, and every 5 days during May. The presence or absence of a CL was recorded for 442 examinations. A blood sample was obtained after each examination, and a functional CL was considered to be present if plasma progesterone concentrations were above 1 ng/ml. Progesterone results were used as the reference to calculate the sensitivity and specificity of palpation per rectum for the diagnosis of a functional CL on different months. Predictive values for the positive and negative diagnoses were calculated using different hypothetical rates of the prevalence of CL. To evaluate the morphological basis of an erroneous diagnosis, ultrasonographic scanning of the ovaries was performed in 264 cases and the physical presence or absence of a CL was registered. The calculations were repeated using the ultrasonographic findings as the reference to evaluate the sensitivity and specificity of the diagnosis of a structural CL by per rectum palpation. Several heifers were not cyclic in March but began to cycle during the study. Thus, the prevalence of both functional and structural CL increased with time. As a result, the proportion of palpation diagnoses classified as true positives increased in May, while the proportion of true negatives decreased. Although the values of sensitivity and specificity remained constant from month to month, the predictive values changed markedly in May, when the predictive value of the positive test increased while the predictive value of the negative test decreased. These changes were due to differences in the prevalence of a CL and not to differences in the palpable characteristics of CLs in different months. The prevalence of a structural CL was always higher than that of a functional CL. The Cohen's Kappa test for concordance revealed better correspondence between palpation per rectum and ultrasound (k = 0.82) than between progesterone and either ultrasound (k = 0.68) or palpation (k = 0.66). These results show that a large proportion of the errors imputed to deficient palpation when progesterone concentrations are used as a reference are in fact the result of lack of correspondence between the physical and functional presence of a CL.

Progress in the chemotherapy of small cell carcinoma of the lung.

A comparison was made between six different approaches to the chemotherapy of small cell carcinoma of the lung. The value of single-agent chemotherapy was compared to combination chemotherapy and radiation therapy, and with cyclic alternating combination chemotherapy in 161 patients. Cyclic alternating chemotherapy with modest radiation therapy to the primary site provided significant advantages over single-agent or combination chemotherapy. A combination of VP-16 + Adriamycin + vincristine seemed particularly effective in inducing an initial objective tumor response rate of 83%, with a projected median survival of 13.2 months. Of patients treated with cyclic alternating therapy, 51% were alive at one year. It thus appears that where complete response is achieved, prolonged disease-free survival can be expected.

Evaluation of sternal bone marrow aspiration for detection of tumor cells in patients with bronchogenic carcinoma.

We evaluated sternal bone marrow aspiration as a routine pretreatment procedure in patients with bronchogenic carcinoma. The overall rate of identification of tumor cells by this technique was found to be low. When oat cell bronchogenic carcinoma was considered as a separate entity, the positive rate was higher. However, in no instance did the bone marrow aspiration result in a change in clinical staging.

The changing histopathology of lung cancer: a review of 1682 cases.

We have reviewed the histopathology of lung cancer patients seen over the past 13 years at RPMI. Assessment of this data indicates that adenocarcinoma is becoming progressively more prevalent as related to the other forms of lung cancer. Factors which in part may account for this increased prevalence are: 1) changes in criteria for reading histopathology of lung cancer, particularly since 1967; 2) the increased incidence of lung cancer among the female population who have a propensity for adenocarcinoma; and 3) occupational and environmental factors. In 1974 adenocarcinoma for the first time became the most prevalent type of lung cancer at RPMI. Whatever the reason, if our data are truly representative of a national trend, adenocarcinoma will soon become the most prevalent type of lung cancer in the United States. This fact may result in an increasing death rate since the present 18-month survival rate for adenocarcinoma is substantially less than for squamous cell carcinoma, which has in the past been the prevalent form of the disease. As the smoking habits of women more closely approximate those of men, we expect that the incidence and mortality of lung cancer will prove to be quite similar in both sexes.

Therapy of advanced squamous carcinoma of the lung: cyclophosphamide vesus "COMB".

The four-drug combination of cyclophosphamide, vincristine, methyl CCNU and bleomycin was compared to CTX alone in a prospective randomized trial. Only one of 20 patients treated with COMB and one of 27 patients treated with CTX achieved a partial response. CTX was associated with a significantly better survival than COMB among patients who were ambulatory at onset of therapy. Survival among non-ambulatory patients was similar with both regimens.

Squamous cell carcinoma of the esophagus: a study of 153 cases.

The incidence of esophageal carcinoma in the United States is relatively low; total estimated cases annually are about 7,000 (Ca, 1975). The overall cure rate, however, is about the worst among all malignant diseases and is reported to be 3% (Ca, 1975). We reviewed cases of squamous cell carcinoma of the esophagus treated at Roswell Park Memorial Institute to understand the clinicopathologic features in order to improve our therapeutic results.

Surgical therapy of lung cancer.

A total of 1,615 patients with a confirmed diagnosis of lung cancer were treated at Roswell Park Memorial Institute between 1963 and 1974. Particular emphasis was given in this review to the 295 patients that underwent surgical resection of their primary lung lesion. Factors such as histology, type of resection, sex, age, staging, and degree of dissemination were considered possible influences on survival. The risks and benefits of intentional reductive or palliative surgery are considered along with the risk related to thoracotomies performed for diagnostic purposes.

Radioisotope scans in the evaluation of metastatic bronchogenic carcinoma.

In this study, we evaluated the accuracy of radioisotope scans in detecting metastatic lesions in patients with bronchogenic carcinoma. To be included in the study, the patient had to have undergone liver, brain, and/or bone scanning within 10 weeks of autopsy. Other means of evaluating these organs for metastatic involvement were used as well. The liver was checked by palpation and by determination of enzyme levels. A history, physical examination, and neurologic examination were used to establish the possibility of brain metastases. For studying bones, a history, physical examination, and conventional x-ray films were employed. Results of the scans and other tests were compared with findings at autopsy, and accuracy rates for each method of study were determined.