Maternal predictors of early breast milk output

Previous attempts to show a quantitative relationship between maternal hormone levels and early milk output have used small sample sizes and simple correlations. Women of mixed parity and similar socio-economic status and education were recruited to a study using multivariate analysis to look for these associations. Hormone levels (oestradiol, progesterone, prolactin and thyrotropin (TSH)) were determined for 91 mothers at four time points (ante- and postnatally) from finger-prick blood spots by fluoro-immunoassay. Milk output at 1 and 4 weeks was determined from 24-h test weighings. Parity was found to be the most significant factor affecting breast milk volume at 1 wk postpartum (multiparous women delivered 142 ml more milk in 24 h than primiparous women). Total time spent feeding had a strong association with breast milk volume, with increasing time having a negative effect. Multiple regression analysis, controlling for parity and time spent feeding, showed a positive association of milk output at 1 wk with antenatal progesterone and antenatal prolactin levels. At 4 wk, higher postpartum oestradiol levels had a negative association and antenatal progesterone levels a positive association with milk output. This study demonstrates that there are quantitative associations between antenatal maternal hormone levels and breast milk output in the early postnatal period.     

Conjugated linoleic acid and the control of cancer and obesity

The effects of conjugated linoleic acid (CLA) in animals are reviewed. In most of the CLA preparations that have been investigated to date for biological activity, two CLA isomers are present in about equal concentrations: cis-9,trans-11 CLA, and trans-10,cis-12 CLA. The occurrence of these isomers in foods and their production by rumen microorganisms are discussed. Potential mechanisms of action as regards the effects of CLA on cancer and body composition are reviewed, including recent evidence that body composition changes are produced by the trans-10,cis-12 CLA isomer. Evidence is presented indicating that CLA may modulate cellular response to tumor necrosis factor-alpha (TNF- alpha). The mechanistic implications of this finding are considered.      

Atopy in parents of children dying with sudden infant death syndrome

36 parents of infants who had died suddenly did not differ in frequency of atopic symptoms, immediate skin tests, IgE, IgE antibody, immunoglobulin G, A, and M, or yeast opsonisation, from 36 matched controls, although atopy was common (about half had atopy in both groups.     

Value of cystography in urinary tract infections

Fifty-one children with a bacteriologically proven urinary tract infection had both an intravenous urogram (IVU) and a micturating cystogram. The IVU was normal in 35. Only 6 of these children showed reflux in the cystogram, affecting 7 of the 70 ureters at risk. Since reflux on its own does not cause renal damage, which occurs only with super-added infection, detection of reflux is not important providing the urine is kept sterile. We suggest that cystography be deferred providing the IVU is normal until recurrent infections occur while under hospital care, and, with this policy this unpleasant and sometimes hazardous investigation could be avoided in many children with a single urinary tract infection.     

Randomized phase II – study evaluating EGFR targeting therapy with Cetuximab in combination with radiotherapy and chemotherapy for patients with locally advanced pancreatic cancer – PARC: study protocol [ISRCTN56652283]

Background

Pancreatic cancer is the fourth commonest cause of death from cancer in men and women. Advantages in surgical techniques, radiation therapy techniques, chemotherapeutic regimes, and different combined-modality approaches have yielded only a modest impact on the prognosis of patients with pancreatic cancer. Thus there is clearly a need for additional strategies. One approach involves using the identification of a number of molecular targets that may be responsible for the resistance of cancer cells to radiation or to other cytotoxic agents. As such, these molecular determinants may serve as targets for augmentation of the radiotherapy or chemotherapy response. Of these, the epidermal growth factor receptor (EGFR) has been a molecular target of considerable interest and investigation, and there has been a tremendous surge of interest in pursuing targeted therapy of cancers via inhibition of the EGFR.

Methods/design

The PARC study is designed as an open, controlled, prospective, randomized phase II trial. Patients in study arm A will be treated with chemoradiation using intensity modulated radiation therapy (IMRT) combined with gemcitabine and simultaneous cetuximab infusions. After chemoradiation the patients receive gemcitabine infusions weekly over 4 weeks. Patients in study arm B will be treated with chemoradiation using intensity modulated radiation therapy (IMRT) combined with gemcitabine and simultaneous cetuximab infusions. After chemoradiation the patients receive gemcitabine weekly over 4 weeks and cetuximab infusions over 12 weeks. A total of 66 patients with locally advanced adenocarcinoma of the pancreas will be enrolled. An interim analysis for patient safety reasons will be done one year after start of recruitment. Evaluation of the primary endpoint will be performed two years after the last patient's enrolment.

Discussion

The primary objective of this study is to evaluate the feasibility and the toxicity profile of trimodal therapy in pancreatic adenocarcinoma with chemoradiation therapy with gemcitabine and intensity modulated radiation therapy (IMRT) and EGFR-targeted therapy using cetuximab and to compare between two different methods of cetuximab treatment schedules (concomitant versus concomitant and sequential cetuximab treatment). Secondary objectives are to determine the role and the mechanism of cetuximab in patient's chemoradiation regimen, the response rate, the potential of this combined modality treatment to concert locally advanced lesions to potentially resectable lesions, the time to progression interval and the quality of life.     

Expanding the therapeutic repertoire of epidermal growth factor receptor blockade: radiosensitization

Expression of epidermal growth factor receptor (EGFR) has been associated with radioresistance in cancer. Moreover, tumour cell recovery after irradiation paradoxically occurs, in part, as a result of activation of EGFR signalling by such treatment. A recent article by Huang, Li, Armstrong and Harari provides strong rationale for considering the anti-EGFR agent ZD1839 ('Iressa') as a radiosensitizing strategy. With the use of several in vitro and xenograft models of human squamous cell head and neck carcinoma, ZD1939 was shown to markedly improve radiotherapeutic response, with superior tumour inhibition and delayed tumour regrowth. Mechanisms underlying this effect included anti-proliferative and pro-apoptotic activity, with significant perturbation of tumour angiogenesis.     

Evaluation of the chronic toxicity and oncogenicity of N,N-diethyl-m- toluamide (DEET)

Chronic toxicity and/or oncogenicity studies were conducted in rats, mice, and dogs with the insect repellent DEET. DEET was mixed in the diet and administered to CD rats for two years at concentrations that corresponded to dosage levels of 10, 30 or 100 mg/kg/day for males and 30, 100, or 400 mg/kg/day for females; to CD-1 mice for 18 months at dosage levels of 250, 500, or 1000 mg/kg/day; and to dogs for one year, via gelatin capsules, at dosage levels of 30, 100, or 400 mg/kg/day. In the rodent studies, each group consisted of 60 animals of each sex, and two concurrent independent control groups, each containing 60 animals/sex were included in each study. Each group in the dog study consisted of four male and four female dogs and one control group was included in the study. Treatment-related effects were observed at the highest dose level in all three studies. For rats, the effects included decreases in body weight and food consumption and an increase in serum cholesterol in females only. In mice, the effects observed were decreases in body weight and food consumption in both sexes. The effects observed in dogs included increased incidences of emesis and ptyalism, and levels of transient reduction in hemoglobin and hematocrit, increased alkaline phosphatase (males only), decreased cholesterol, and increased potassium. One male dog in the high-dose group also exhibited ataxia, tremors, abnormal head movements, and/or convulsions on several occasions during the study. The highest no- observed-effect levels (NO-ELs) for rats, mice and dogs were determined to be 100, 500, and 100 mg/kg/day, respectively. No specific target organ toxicity or oncogenicity was observed in any of the studies.      

The multifaceted roles of nitric oxide in cancer

The roles of nitric oxide (NO) in numerous disease states have generated considerable discussion over the past several years. NO has been labeled as the causative agent in different pathophysiological mechanisms, yet appears to protect against various chemical species such as those generated under oxidative stress. Similarly, NO appears to exert a dichotomy of effects within the multistage model of cancer. Chronic inflammation can lead to the production of chemical intermediates, among them NO, which in turn can mediate damage to DNA. Yet, NO also appears to be critical for the tumoricidal activity of the immune system. Furthermore, NO can also have a multitude of effects on other aspects of tumor biology, including angiogenesis and metastasis. This report will discuss how the chemistry of NO may impact the initiation and progression stages of cancer.      

Treatment of respiratory failure in an infant with bronchopulmonary dysplasia infected with respiratory syncytial virus using inhaled nitric oxide and high frequency ventilation

A 2-month-old, former 28-week premature infant with brochopulmonary dysplasia infected with respiratory syncytial virus was treated with nitric oxide and high frequency oscillatory ventilation after conventional therapy failed. Nitric oxide and high frequency oscillatory ventilation rapidly improved oxygenation allowing recovery without the need for extracorporeal membrane oxygenation. This treatment regimen should be considered as an option in high-risk infants with respiratory syncytial virus infection who meet extracorporeal membrane oxygenation criteria.     

Sequence-Based Classification Scheme for the Genus Legionella Targeting the mip Gene

The identification and speciation of strains of Legionella is often difficult, and even the more successful chromatographic classification techniques have struggled to discriminate newly described species. A sequence-based genotypic classification scheme is reported, targeting approximately 700 nucleotide bases of the mip gene and utilizing gene amplification and direct amplicon sequencing. With the exception of Legionella geestiana, for which an amplicon was not produced, the scheme clearly and unambiguously discriminated among the remaining 39 Legionella species and correctly grouped 26 additional serogroup and reference strains within those species. Additionally, the genotypic classification of approximately 150 wild strains from several continents was consistent with their phenotypic classification, with the exception of a few strains where serological cross-reactivity was complex, potentially confusing the latter classification. Strains thought to represent currently uncharacterized species were also found to be genotypically unique. The scheme is technically simple for a laboratory with even basic molecular capabilities and equipment, if access to a sequencing laboratory is available.The genus Legionella comprises approximately 40 species, at least 7 of which have more than one serotype (3, 15, 31). Approximately half of the species have been associated with human disease (28). Legionella-like organisms isolated from clinical specimens, or from the environment during the course of an outbreak, need to be identified to elucidate the disease process and to identify the source. Legionellae have proved to be relatively unreactive when traditional biochemical tests are utilized, necessitating more complex identification methods (6, 7, 26, 41). Serologically based methods are widely used in clinical laboratories, but antigen cross-reactivity limits specificity and restricts their confident use to a few frequently isolated species (38). This is especially true for countries where legionellosis caused by species other than L. pneumophila is common (12). More complex classification schemes have been proposed (26, 38), the most successful being one based on the range and proportion of cellular fatty acids and ubiquinones (21, 22, 40, 43). As additional species have been characterized, this method has become less discriminating, since apparently unique patterns were proved to be shared by several species (43). The inclusion of hydroxylated fatty acids has improved discrimination, but it requires the analysis of both mono- and dihydroxylated fatty acids, and individual patterns are complex, making analysis difficult (21).Gene sequence-based phylogenic (genotypic) schemes have become widely used for organisms which are difficult to classify, as more sequences have been determined and sequencing methods have become simpler, more widely available, and cost effective (11, 23, 24, 29, 32, 34). Genotypic schemes have the great advantage of being unaffected by colony age and growth conditions and, in contrast to chromatographic methods, are not subject to extraction and chromatographic conditions or constituent equipment. Additionally, because a gene sequence is essentially a long digital string, with each digit being one of only four nucleotides, genotypic schemes are less ambiguous and can utilize significantly more discriminatory data than phenotypic ones, and in a form that lends itself to widely available computer analysis software. Many genotypic schemes utilize variation in the 16S rRNA sequence (11, 23, 24, 32, 34), because of the ease with which regions can be amplified and sequenced with universal primers. The 16S rRNA sequences of Legionella species have been reported (18), as have the sequences of the mip gene (2, 12, 13, 31), which codes for an immunophilin of the FK506 binding protein (FKBP) class (14). This protein, which ranges in size from 232 to 251 amino acids, depending on the Legionella species (31), is an outer membrane protein important in the intracellular cycle of Legionella. While it is known to be involved with the survival of the bacterium immediately after uptake into phagocytic cells (9, 12, 28), its exact role is unclear. Additionally, analogs are found widely in both prokaryotes and eukaryotes and are likely to have a significant cellular role (14). Other gene sequences have been determined for Legionella (5, 17, 36), but only the rRNA sequences and the mip gene have been comprehensively determined for most species, an essential prerequisite for any gene to be the basis of a genotyping scheme. Ratcliff et al. (31) recently phylogenetically compared most Legionella species, using the species variation among both the 16S rRNA and mip genes, and found over twice the variation in the mip gene at the DNA level (56% of base sites) as in 16S rRNA (23% of base sites). A pairwise comparison of species reveals a mip gene variation of 3 to 31% (mean, 20%) between species pairs compared with 1 to 10% (mean, 6%) for 16S rRNA. For the mip gene, interspecies nucleotide variation occurred throughout the gene but especially within a hypervariable insert of up to 51 bases immediately adjacent to the region coding for the signal sequence, at redundant third codon sites, and in sequences coding for either single or small regions of variable amino acids interspersed among regions coding for total or near-total amino acid homology, especially toward the 3′ end of the gene (31). These last regions are known to encode the active portions of the protein’s enzymatic peptidylprolyl cis-trans-isomerase (PPIase) activity (31).Additionally the mip gene appeared to be relatively stable genetically, with no evidence of homologous recombination, in that identical or near-identical sequences were not found for the mip genes from phenotypically divergent species. With respect to genetic stability, the mip gene may therefore behave like housekeeping genes, which are known to be more stable than other gene classes (1). Homologous recombination would severely compromise a sequence-based classification scheme (1), and it is a theoretical possibility at least for rRNA targets (37). Thus, the genetic stability and greater mutational variation of the mip gene suggest that it is an ideal target for a classification scheme, with results likely to be more discriminating in identifying species and more resilient to clonal variation within each species. It may even be possible to discriminate between serogroups where these are present or to demonstrate distinct intraspecies clonal groups.The present study reports the use of the mip gene to develop a sequence-based classification scheme for Legionella, the first proposed for this genus. Further, it reports the comparison of sequences from species which have additional serogroups, to determine if serogroups can be discriminated. Similarly, it reports the comparison of sequences from wild strains isolated on several continents, for which there is confirmatory phenotypic or DNA hybridization identification data, to test the robustness of the scheme for variation within strains of the same species. Lastly, isolates which appear phenotypically or from DNA hybridization studies to be different from currently characterized species were tested to determine if a sequence-based classification scheme can clarify their identities. Some of these unusual isolates have been previously reported (43).