Inheritance of Resistance to Meloidoygne incognita in Primitive Cotton Accessions from Mexico.

Few sources of resistance to root-knot nematodes (Meloidogyne incognita) in upland cotton (Gossypium hirsutum) have been utilized to develop resistant cultivars, making this resistance vulnerable to virulence in the pathogen population. The objectives of this study were to determine the inheritance of resistance in five primitive accessions of G. hirsutum (TX1174, TX1440, TX2076, TX2079, and TX2107) and to determine allelic relations with the genes for resistance in the genotypes Clevewilt-6 (CW) and Wild Mexico Jack Jones (WMJJ). A half-diallel experimental design was used to create 28 populations from crosses among these seven sources of resistance and the susceptible cultivar DeltaPine 90 (DP90). Resistance to M. incognita was measured as eggs per g roots in the parents, F(1) and F(2) generations of each cross. The resistance in CW and WMJJ was inherited as recessive traits, as reported previously for CW, whereas the resistance in the TX accessions was inherited as a dominant trait. Chi square analysis of segregation of resistance in the F(2) was used to estimate the numbers of genes that conditioned resistance. Resistance in CW and WMJJ appeared to be a multigenic trait whereas the resistance in the TX accessions best fit either a one or two gene model. The TX accessions were screened with nine SSR markers linked to resistance loci in other cotton genotypes. The TX accessions lacked the allele amplified by SSR marker CR316 and linked to resistance in CW and other resistant genotypes derived from this source. Four of five TX genotypes lacked the amplification products from the marker BNL1231 that is also associated with the resistant allele on Chromosome 11 in WMJJ, CW, NemX, M120 RNR and Auburn 634 RNR. However, all five TX genotypes produced the same amplification products from three SSR markers linked to the resistant allele on Chromosome 14 in M120 RNR and M240 RNR. The TX accessions have unique resistance genes that are likely to be useful in efforts to develop resistant cotton cultivars with increased durability.

Developing an international nursing partnership with Nicaragua.

With health conditions in the "least developed countries persisting at levels that are so limiting and destructive of human potential ... as to be unacceptable to the global community", WHO has put out a call for mandates to address these problems with "new approaches ... new partnerships." One answer to this call has come from the US' Duquesne University School of Nursing, which has founded an education and service partnership with Nicaragua that can serve as a "grass roots" model others can follow.

Comment on the paper, "Growth of yeast cultures as in vitro model for investigationg homoeopathic remedies"

A recent paper by Steffen repeating earlier work by Jones et al. failed to confirm any effect of potencies of Pulsatilla on the growth rate of cultures of Saccharomyces cerevisiae which had previously been reported. We find that using a more specific statistical test on the results given by Steffen it can be shown that these results contain almost the same periodicity with potency that Jones et al. reported, although only corresponding to a variation of +or- l.5//about the mean value

Clinical features of ciguatera fish poisoning: a study of the disease in the US Virgin Islands.

Clinical data were obtained on 33 patients involved in 27 episodes of ciguatera fish poisoning occurring during a 14-week period on St Thomas in the US Virgin Islands. All patients had gastrointestinal tract symptoms, with 30 patients (91%) complaining of diarrhea and 23 patients (70%) complaining of vomiting; these symptoms occurred early in the disease and were of short duration. Twenty-three patients (70%) complained of malaise, and 19 patients (58%) had pain and weakness in the lower extremities. Dysesthesias were noted by 19 patients (58%); the median duration of dysesthesias was two weeks or more, with symptoms present is some cases for more than two months. Cardiovascular signs and symptoms, including both hypotension and bradycardia were noted in some acute cases. Therapy included antidiarrheal and antiemetic agents, intravenous fluids, atropine, and pralidoxime chloride. Efficacy of pralidoxime therapy could not be established on the basis of our data.

Ciguatera fish poisoning epidemiology of the disease on St. Thomas, U.S. Virgin Islands.

In a random household survey conducted on St. Thomas, U.S. Virgin Islands, the incidence of ciguatera fish poisoning was found to be 36.5 cases per 1,000 population per 5 years (95% confidence limits +/- 16.9 cases per 1,000 population per 5 years). An average of 3.6 cases per 1,000 population per year were diagnosed in the hospital emergency room on St. Thomas. Cases seen in the emergency room occurred most frequently among persons aged 30-39 years. No clear seasonality for cases could be demonstrated. In an investigation of cases occurring between 1 January and 10 April 1980, illness was caused by a variety of different fish, with carrang (Caranx ruber) the species most commonly implicated. Patients and age-matched controls ate fish with equal frequency; patients were significantly more likely to have had previous episodes of ciguatera fish poisoning than were controls.

Host resistance factors in human milk.

PIP: This paper discusses the nature of host resistance factors in human milk and epidemiologic studies regarding infections and mortality rates in breastfed and nonbreastfed babies. The defense factors and their proposed modes of action are: 1) a growth enhancer of lactobacilli, which interferes with intestinal colonization of enteric pathogens; 2) antistaphylococcal factors, which inhibit staphylococci; 3) secretory IgA and other immunoglobulins, which protect the gut and respiratory tract; 4) C4 and C3 (complement components; C3 fragments have opsonic, chemotactic, and anaphylatoxic activities); 5) lysozome, lysis of bacterial cell wall; 6) lactoperoxidase, killing of streptococci; 7) lactoferrin, kills microorganism by chelating iron, and 8) macrophages and lymphocytes, phagocytosis and cell-mediated immunity. Although it can be postulated that the breastfed infant's resistance to infection would be superior on account of the greater presence of these factors in human milk compared to cow's milk, little is known about the effects of these defense factors on the infant. Epidemiologic studies have reported on the lower morbidity and mortality rates of breastfed infants as compared to bottlefed infants. Other studies have focused on the protective effects of human milk upon the infant, but these have been inconclusive. In countries with poor sanitation and high infection rates, the incidence of bacterial infections is lowest in breastfed infants. The advantages of human milk however are difficult to demonstrate in societies with high standards of sanitation and low infection rates. Infection and mortality rates in infants have in fact declined in developed countries as the practice of breastfeeding declined. Until it is established that immunity to common pathogens is transmitted to the infant by human milk, it will not be known whether human milk does have protective effects.^ieng