Levels of maternally transferred antibodies against the surface antigen of the A/Texas/1/77 strain of influenza virus showed the expected decline during infancy when measured by complement fixation (CF). However, this decline was not observed when these antibodies were measured by haemagglutination-inhibition (HI). It has been postulated that this discrepancy is due to the acquisition, in the early days of life, of non-specific serum factors which increase the HI activity of sera. The levels of these factors were determined indirectly by calculating HI: CF ratios and it was shown that the factors are rapidly acquired by children between the fifth and twentieth week of life.

1. The view is advanced that the endotoxin of the meningococcus is one of a group of thermostable intracellular bacterial poisons, and that it is not a specific antigenic toxin. 2. The inability of the “endotoxin” to function as an antigen does not lessen its importance as a pathogenic factor in cerebrospinal fever, since the lesions that are associated with the presence of the meningococcus in the tissues are apparently attributable to the pyogenic action of the intracellular poison.

The organisms examined have been killed, (a) by temperatures which should not have destroyed the reducing enzyme, (b) by sodium fluoride and four other antiseptics, derivatives of phenol, and (c) by acetone. In each case there has been total destruction of the reducing power, any apparent production of nitrite from nitrate being too slight to justify the assumption that it is due to anything more than experimental error. Filtrates of fluid cultures have also failed to reduce. The results may be summed up as follows:

(1) The reduction of nitrite by certain dysentery bacilli is not due to a soluble extra-cellular enzyme.

(2) Dysentery bacilli and B. coli killed by a minimal degree of heat have little if any effect in reducing nitrites.

(3) Organisms killed by antiseptics or by acetone do not reduce nitrates and nitrites.

(4) Even where all the organisms are not dead, reduction may be prevented by antiseptics.

(5) The high antiseptic value of tetrachlor-o-biphenol, tetrabrom-o-kresol, p-chlor-m-kresol and hexabrom-dioxy-diphenyl-carbinol has been established for the organisms of the dysentery group.

The microporous polyethylene hollow fibre membrane is capable of adsorbing small-sized lipopolysaccharides (LPS) prepared by sonication dispersion, column chromatography on Sephadex G-75 and filtration through a filter membrane with a nominal pore size of 0·025 μg. Small-sized LPS had a one-thousandth of endotoxin activity as compared to intact LPS, when determined by the Synthetic Chromogenic Substrate method of LAL with a specific endotoxin activity of 73·7 ng/μg LPS. Fluorescent microscopy of fluorescein conjugated LPS on a microporous polyethylene hollow fibre showed that fiuorescein-LPS was adsorbed through the entire depth of the membrane texture. Accordingly the adsorption capacity of the filter for small-sized LPS was determined as 1·65 mg LPS/3·68 m2 surface/116 mg fibre/module.

This study used linked national tuberculosis (TB) and HIV surveillance data to investigate recent trends and factors associated with HIV co-infection (TB-HIV) in healthcare workers (HCWs) with TB in England and Wales. Methods applied were the χ2 trend test and logistic regression. Overall 14% (231/1627) of HCWs with TB were co-infected with HIV, increasing from 8% in 1999 to 14% in 2005 (P<0·001). Most (78%) HCWs were non-UK born and 74% of these developed TB ⩾2 years post-entry. Being born in Sub-Saharan Africa was an independent predictor for TB-HIV, especially for female HCWs (odds ratio 66·5, 95% confidence interval 16·3–271·1), who also had a lower median CD4 count than other co-infected women (106/mm3, interquartile range 40–200, P<0·01). Voluntary HIV testing of new HCWs should be encouraged as an opportunity for early diagnosis. Post-entry, a high index of clinical suspicion for TB in those most at risk remains important.

Of 32983 specimens from 307 sources in England and Wales tested in the Virus Reference Laboratory for anti-HIV between 1984 and 1987, 6491 (20%) were positive. Ninety-five per cent of the positive subjects were male and 44% of them were from three London genito-urinary medicine clinics. In 1987 the numbers of newly diagnosed HIV infections decreased in homosexual men and haemophiliacs and increased in injecting drug abusers; 148/119 (12%) of all the positive findings in 1987 were in females. Between 1984 and 1987 the proportion of anti-HIV positive individuals who were asymptomatic fell by nearly 10% and the proportion with AIDS/ARC rose by nearly 10%. Of the requests leading to positive results 1280 (20%) were recognized as duplicates of previous positive results, while for 34 % of the requests no clinical information was provided. These deficiencies in the data compromise HIV surveillance based on diagnostic testing, and supplementary bias-free data are needed.

For a considerable number of years, Belfast has suffered from a high typhoid fever death-rate, and the investigations embodied in the following pages were undertaken at the request of the Corporation, with the purpose of determining the sanitary measures required to prevent, as far as possible, the occurence of typhoid fever in the city.

The preparation of a medium that would allow the bacillus of diphtheria to grow and exclude all other organisms would be an ideal medium for those whose work is concerned with that organism, but, as such a medium has not yet been devised, we must be content with the modifications of the ordinary media which we possess. Various varieties of media have been prepared for the purpose of favouring the growth of B. diphtheriae, but very little seems to have been done with regard to selective media.

In earlier papers (Gordon, 1930) it was shown that congo red has an inactivating effect on serum complement, both haemolytic and bactericidal, and that this effect can be reversed by treating the serum and congo red mixture with charcoal, the charcoal removing the congo red and leaving the complement active again. A similar reversal of inactivation is obtained by using instead of the charcoal, heated serum (55° C. for 30 min.) or protein solutions. Later (Gordon, 1931), it was shown that congo red had an inactivating effect on the haemolysins of Streptococcus haemolyticus and B. welchii. The reversibility of this effect was not so easy to demonstrate as with complement. Charcoal had a destructive effect on the haemolysins and so could not be used. It was found, however, that when the concentration of congo red was just sufficient to neutralize the streptococcal haemolysin, the addition of cuprammonium artificial silk adsorbed the congo red and liberated the haemolysin. In the case of B. welchii this method of reversal was not suitable, as the artificial silk had a destructive effect on the haemolysin. Instead, reversibility was demonstrated by adding ox serum to the mixture of congo red and haemolysin. This brought about a redistribution of the congo red between the ox serum and the haemolysin and if the amount of congo red used had been only just sufficient to neutralize the haemolysin of B. welchii, then the haemolytic activity could again be demonstrated. Gordon and Robson (1933) showed that congo red interfered with the anaphylactic reaction tested both in vivo and in vitro, the guinea-pig uterus being used in the in vitro experiments, in which the inhibitory action of the dye was shown to be reversible. It was suggested that the congo red interfered with the entrance of antigen into the cell.

The specificity of human antibodies for the two major sidechain determinants of the type II group B streptococcal (GBS) polysaccharide was examined in 90 pairs of maternal and cord sera. Using an ELISA system, total antibody was measured against the complete (sialylated) type II antigen and the proportion of antibody against the galactose determinant was estimated by inhibition with free β–methylgalactopyranosided. Mothers colonized by type II or by other GBS types had higher levels of total specific antibody (means, 33 and 4–7 µg/ml, respectively) than those not colonized (mean, 2–2 µg/ml). Cord sera averaged 1–2 µg/ml lower than maternal sera. Colonization with GBS was also associated with higher levels against the galactose determinant (mean, 1.5&µg/ml, compared to 0–7µg/ml for those not colonized). The distribution of specificities favoured antibodies against the sialic acid determinant in maternal but not cord sera. Specificity as well as antibody level may play a role in the epidemiology of GBS type II.

The efficacy of the conventional bacille Calmette-Guérin (BCG) vaccine is often questioned because of conflicting trial results [1]. In this context, a new BCG vaccine developed by Grode et al. [2] has been seen as a favourable development in tuberculosis (TB) control [3]. BCG vaccine development is a challenge for many reasons, not least of which is the complex immunology of mycobacterial infections. The pathogenesis of TB, and prevention of TB by BCG, is predominantly a function of cell-mediated immunity. Mycobacterium tuberculosis (MTB) and BCG are phagocytosed, but remain viable for some time within the phagosome. There, BCG antigens must be presented to major histocompatibility complex (MHC) class II molecules to activate CD4+ cells, and to MHC class I molecules to activate CD8+ cells [3]. However, both MTB and BCG fail to activate CD8+ cells sufficiently. The relative failure of activation of CD8+ cells is thought to be related to the enzyme urease, which keeps the intracellular pH high and thus inhibits presentation of antigens to T cells which would otherwise activate the CD8+ response. Grode et al. [2] have engineered a BCG strain which overcomes this problem and allows release of antigen into the cell and thereby stimulates a CD8+ cell response in addition to the CD4 response seen with conventional BCG. They did this first by engineering a strain of BCG which secretes listeriolysin (Hly), an enzyme from Listeria monocytogenes which perforates cell membranes.

In the handling of milk no single factor is of more importance than the cleanliness of the vessels used, and steam sterilisation is an essential part of correct cleansing technique of dairy utensils. Although several hundred dairy farmers have installed apparatus for steam sterilisation, the majority are still content with less efficient methods and rely upon “scalding” as the final operation in washing a utensil, although the water used for scalding is seldom at a sufficiently high temperature to kill many bacteria, and it is usually poured from one vessel to another in the hopes of efficiently finishing the cleansing processes although it is only comfortably warm to the fingers.

The subject I propose to discuss in the present and subsequent papers is of importance in two ways. Popular traditions have frequently implied that the age at which a parent begets offspring is not without influence upon the characters of the latter, the prevailing belief being humorously portrayed in the late W. S. Gilbert's ballad “The Precocious Baby.” Again, recent thinkers, notably Professor Karl Pearson, have asserted that elder born children differ markedly in liability to certain diseases from their younger brethren. Were this view to be accepted it would be relevant to enquire whether the difference might not be a function of the age of the parents at the time of birth of the offspring or at least whether such difference might not play a part in bringing about this result. Assuming that any such effect could be demonstrated, it is plain that a valuable stimulus would be given to the study of physiological changes in the reproductive system within the fertile period. These are the immediately interesting aspects of the subject, but with them I am less directly concerned than withcertain secondary consequences.

Tuberculosis (TB) is the leading cause of death caused by single pathogenic microorganism, Mycobacterium tuberculosis (MTB). The study aims to explore the associations of microRNA (miRNA) single-nucleotide polymorphisms (SNPs) with pulmonary TB (PTB) risk. A population-based case−control study was conducted, and 168 newly diagnosed smear-positive PTB cases and 251 non-TB controls were recruited. SNPs located within miR-27a (rs895819), miR-423 (rs6505162), miR-196a-2 (rs11614913), miR-146a (rs2910164), miR-618 (rs2682818) were selected and MassARRAY® MALDI-TOF System was employed for genotyping. SPSS19.0 was adopted for statistical analysis, non-conditional logistic regression was performed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed to estimate the associations. Associations of haplotypes with PTB risk were performed with online tool. Rs895819 CT/CC genotype was associated with reduced PTB risk among female population (OR = 0.45, 95% CI: 0.23–0.98), P = 0.045. Haplotypes (combined with rs895819, rs2682818, rs2910164, rs6505162 and rs11614913) TCCCT, TAGCC, CCCCC, CCGCT and TCGAT were associated with reduced PTB risk and the ORs were 0.67 (95% CI: 0.45–0.99), 0.49 (0.25–0.94), 0.34 (95% CI: 0.14–0.81), 0.22 (95% CI: 0.06–0.84) and 0.24 (95% CI: 0.07–0.79), respectively; while the haplotypes of TAGCT, CCCCT, CACCT and TCCAT were associated with increased PTB risk, and the ORs were 3.63 (95% CI: 1.54–8.55), 2.20 (95% CI: 1.00–4.86), 3.90 (95% CI: 1.47–10.36) and 2.95 (95% CI: 1.09–7.99), respectively. Rs895819 CT/CC genotype was associated with reduced female PTB risk and haplotype TCCCT, TAGCC, CCCCC, CCGCT and TCGAT were associated with reduced PTB risk, while TAGCT, CCCCT, CACCT and TCCAT were associated with increased risk.

Two indirect methods were used to estimate the point prevalence of HIV infection in England and Wales at the end of 1993 using data on diagnosed HIV infections, AIDS cases, HIV-related deaths and HIV testing behaviour from unlinked anonymous surveys. The methods estimated the proportion of all prevalent HIV infections that diagnosed infections represented. Most of those exposed to HIV infection through injecting drug use or sexual intercourse between men had had their infections diagnosed compared to less than half of those exposed through heterosexual intercourse. The total estimated number of prevalent infections was 22350 for the diagnosis interval method and 20540 for the test history method, and about 56–57% of these were in homo/bisexual men. These indirect methods are cheap and simple applications of surveillance data which provide estimates that compare favourably with those produced by more complex methods.

A pre-scorbutic condition has been described, but not, as far as the writer is aware, a pre-Beriberi condition, to the existence of which it is the purpose of this communication to draw attention.

An experimental model simulating infection of the urinary tract was used to investigate factors influencing the transfer of plasmid-mediated drug resistance in the human bladder in the absence of antibiotic therapy. When a small number of cells carrying plasmid-mediated drug resistance was added to an established population of sensitive cells, it was found that varying the physical conditions of the bladder model had no significant effect on the spread of the plasmid and, under all conditions used, exponential spread of the plasmid through the originally sensitive population occurred. When the initial donor cells were killed shortly after addition to the model, exponential transfer of resistance amongst the established sensitive population still occurred. Thus, even in the absence of antibiotic therapy, only a small number of initial transfer events was required for a fully resistant population to be developed. This was true of both actively multiplying and early stationary phase cultures. An initially greater proportion of resistant cells, or the use of an antimicrobial agent to which some of the cells are resistant, would ensure that this process occurred more rapidly.

In works on Public Health and Water Analysis, it is a common observation that the amount of chlorine in inland surface waters near the seaboard is considerably higher than what obtains in samples from more inland parts.

H phase II → phase I conversion of Salmonella thompson was studied at different temperatures. All strains were isolated from one outbreak, and a convenient method of phase conversion was sought. In our hands this was best effected at 20° C.