Complex dynamics of multilocus systems subjected to cyclical selection.

Earlier we have shown that oscillations with a long period ("supercycles") may arise in two-locus systems experiencing cyclical selection with a short period. However, this mode of complex limiting behavior appeared to be possible for narrow ranges of parameters. Here we demonstrate that a multilocus system subjected to stabilizing selection with cyclically moving optimum can generate ubiquitous complex limiting behavior including supercycles, T-cycles, and chaotic-like phenomena. This mode of multilocus dynamics far exceeds the potential attainable under ordinary selection models resulting in simple behavior. It may represent a novel evolutionary mechanism increasing genetic diversity over long-term time periods.     

Genetic selection of growth-inhibitory sequences in mammalian cells.

To assess the role of mitogenically activated genes in the control of cell proliferation, we have taken a genetic approach based on the premise that blocking the function of an essential gene should lead to growth inhibition. Using a newly developed selection procedure, we isolated growth-inhibitory sequences from a pool of random cDNA fragments of 19 growth-related genes associated with the G0/G1 transition. These sequences encode potential dominant negative variants of c-Fos, JunB, and p44MAPK that may interfere with their growth-related functions. We anticipate that this procedure, which allows for the selection of sequences that cause a growth-inhibition phenotype, may have broad applications in the identification and analysis of genes that regulate cell growth.     

Genetic variation as a test of natural selection.

Allozymic variation encoded by 26 loci was analyzed electrophoretically in 507 specimens representing 12 populations of green toads, Bufo viridis, in Israel and the Vis Adriatic Island. Genetic variation in Bufo viridis is higher than in any vertebrate yet studied. Mean heterozygosity per locus per individual (H) is 0.133 (range, 0.105 to 0.159). H is higher in central populations as compared with isolates, and varies among four major protein classes, being highest in transferases and hydrolases and lowest in oxidoreductases and nonenzymatic proteins. Differential gene frequencies among polymorphisms was tested as an indicator of natural selection. Significant heterogeneity between loci in their apparent inbreeding coefficients Fe=S-2p/P(1-p) was found for all alleles and for each of the four major classes of proteins tested, which may be taken as evidence of selection. Both uniform and diversifying selection are suggested by the low and high Fe values, respectively. The general pattern of high heterozygosity in Bufo viridis is best explained as an adaptive strategy in heterogeneous environments.     

Anaphylaxis caused by cauliflower.

BACKGROUND: Cauliflower is a vegetable belonging to the family Cruciferae, genus Brassica, var. Botrytis. METHODS: We report the case of a 70 year-old man who suffered an acute episode consisting of oropharyngeal itching, facial and hand swelling, dyspnea and severe bronchospasm within a few minutes after eating vegetable paella containing cauliflower, green beans, red and green pepper. Due to the severity of the reaction he needed treatment in the emergency room. RESULTS: Skin prick tests with common aeroallergens were positive to Cupressus, Platanus and grass pollen. A strong skin prick test response was obtained with cauliflower and peach lipid transfer protein. Skin prick test with rice, green beans and pepper were negative. Specific IgE determinations were positive to cabbage and cauliflower, and negative to mustard. CONCLUSIONS: The clinical history and the results of the allergologic work-up point out to this patient having experienced an IgE-mediated anaphylactic reaction to cauliflower. To the best of our knowledge, this is the first case report of anaphylaxis due to cauliflower.     

Fever caused by metapramine. Diagnosis of fever caused by psychotropic drugs

Because of two hyperthermias, due to metapramine a french antidepressives of the tricyclic family, international literature concerning drug fever induced by psychotropics was reviewed. This study stresses the fact that apart from neuroleptics which are frequently involved in that type of accident, other psychotropics are very rarely responsible of hyperthermia. One hundred and five cases published since 1970 and sufficiently well documented to be analysed according to Dangoumeau's french method of imputation of side effects of drugs, were reviewed. Among these cases, one hundred (95%) corresponded to malignant syndrome of neuroleptics, 89 concerned neuroleptics alone, and 11, neuroleptics associated with other psychotropics. Regarding the different mechanisms which can explain drug fever as described by Lipsky, it seems that concerning psychotropics two types may be retained: Fever due to central dysregulation directly induced by drugs, and mainly, immunoallergic fever, the most frequently seen as described in our two cases.     

Rescue of the hypoplastic lung by prenatal cyclical strain

We determined the effects of sustained and cyclical prenatal mechanical strain on the hypoplastic lung of the ovine model of congenital diaphragmatic hernia. Over a period of 4 weeks in late gestation, repeated cyclical tracheal occlusion for 23 hours with 1-hour release stimulated minimal growth, but promoted maturation with the development of a saccular lung. In contrast, a cycle consisting of 47 hours with 1-hour release induced optimal lung growth and morphologic maturation of the hypoplastic lung parenchyma. Sustained occlusion resulted in exaggerated lung growth, exceeding that of unaffected controls, and abnormal alveolar development. The extent of induction of lung growth by mechanical strain was inversely proportional to the number of alveolar type II cells remaining in the lung epithelium. These studies show that, although mechanical strain is capable of inducing lung growth and differentiation, cyclical strain is a prerequisite for normal development and that mechanically induced growth occurs at the expense of the alveolar type II cell. We conclude that cyclical strain may allow optimal alveolar development while maintaining a population of alveolar type II cells and may thus facilitate an improvement in postnatal lung function in infants with congenital diaphragmatic hernia.     

Deaths caused by physical restraints.

A retrospective analysis of 122 deaths caused by vest and strap restraints found that most victims were women (78%) and a median age of 81. Victims were found suspended from chairs (42%) or beds (58%); 83% were in nursing homes. Detailed analysis of 19 cases showed that all were demented, 13 had impulsive or involuntary movements, and 14 had recently tried to escape from a restraint or been found in a dangerous position while restrained. Restraints are an underrecognized, underreported, avoidable, and proximate cause of at least 1 of every 1,000 nursing home deaths.     

Artifacts caused by cell microinjection.

The effects of microinjection on Rana pipiens oocytes were determined using cryomicrodissection to measure Na, K, water, and injected radiolabeled sucrose (in gelatin) in the nucleus, animal, and vegetal ooplasm and injected bolus (reference phase, RP). The results point to potential problems in the interpretation of microinjection experiments. When oocytes were injected and incubated in Ringer's solution, nucleus, ooplasm, and RP lost K and sucrose and gained Na. Patterns of loss and gain were complex but were consistent with continuous solute leakage at the injection site causing artifactual intracellular diffusion gradients. In spite of leakage, oocytes completed scheduled meiotic maturation when exposed to progesterone. When oocytes were microinjected and incubated in paraffin oil (a medium in which polar solutes cannot exchange), nuclear and ooplasmic Na, K, and water concentrations remained identical to those in uninjected cells. Neither microinjection per se nor the injected bolus affected intraoocytic solute distributions. These findings imply that, after microinjection in aqueous media, metabolites are lost from and redistribute in cells, and that these artifactual changes are inadequately reflected in the ability of the cell to carry out a complex process. They also show that injection artifacts can be avoided by injecting and incubating cells under paraffin oil.     

Pericarditis caused by Histoplasma capsulatum.

Sixteen patients with pericarditis caused by Histoplasma capsulatum were studied. Fourteen were less than 30 years old, and no patient had an underlying illness or was receiving immunosuppressive therapy. All patients experienced a flu-like prodromal illness lasting from 2 weeks to 4 months. Pneumonitis or hilar adenopathy, or both, was found in 12; pleural effusion, uncommon in primary pulmonary histoplasmosis, was found in seven patients. Pericardial fluid, pleural fluid and bone marrow cultures yielded no growth. All patients demonstrated a fourfold or greater change in complement-fixing antibody titers. No patient had disseminated disease, and only one required treatment with ampholericin B. The illness ran a protracted course, and in six patients symptomatic pericarditis recurred. Ultimately all recovered. Ten patients were restudied 6 months to 12 years after recover. Only one patient had pericardial calcification, and none had constrictive pericarditis. This form of granulomatous pericarditis, unlike that caused by Mycobacterium tuberculosis, appears to carry a good prognosis.     

Urticarial reaction caused by ethanol.

BACKGROUND: We report a case of an urticarial reaction after drinking alcohol beverages. The patient was a 47-year-old man suffering urticarial and anaphylactoid reaction to alcohol for two years. These reactions were observed at every alcohol beverages intake. CASE SUMMARY: We performed a prick test with diluted ethanol, alcohol beverages and their metabolites (acetaldehyde, acetic acid). Only acetic acid showed a positive result. Oral challenge test with diluted-ethanol caused pruritus and swelling of his lips. An oral challenge test with 8% diluted Shochu (Japanese distilled alcohol from rice or wheat) caused wheals on his upper back. DISCUSSION: Only acetic acid, a metabolite of alcohol, induced a positive prick test in the patient with alcohol-induced urticaria. This result was not observed in normal volunteers. An oral challenge test with diluted-alcohol or Shochu showed a positive wheal reaction in a dose dependent-manner which suggests that urticaria seen in this patient might be induced by alcohol-intolerance. However possible allergic reaction to acetaldehyde could not be excluded.     

Endocarditis caused by Salmonella enteritidis.

A case of endocarditis caused by Salmonella enteritidis is reported in a 20-year-old African woman. This is only the fourth published case. The development of this rare infection in the patient reported here probably resulted from a reduction in immunity caused by pregnancy and a past splenectomy.     

Endocarditis caused by Candida parapsilosis.

The authors report a case of endocarditis caused by Candida parapsilosis. To the best of our knowledge, a case has not been described previously in Japan in the English literature. A battery of 8 peroxidase-labeled lectins was tested on sections of paraffin-embedded tissue to determine which lectin could be used in the microscopic diagnosis of C. parapsilosis. One lectin, from Archis hypoaea (PNA) was found to react with C. parapsilosis. On the other hand, C. albicans, Aspergillus, Mucor, and Cryptococcus did not react with A. hypoaea (PNA). On fluorescence microscopic study, C. parapsilosis was not fluorescent, but other fungi were fluorescent when exposed to ultraviolet illumination. Therefore, we propose new procedures for identification of C. parapsilosis in tissue sections using lectin histochemistry and fluorescence microscopy.     

Anaphylactoid reaction caused by moxifloxacin.

We report on a patient who suffered an anaphylactoid reaction because of moxifloxacin.