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C Hill

Publications and source records attributed to C Hill.

At least 253 records · Page 14Linked to original sources
PubMed1991

In vivo genetic exchange of a functional domain from a type II A methylase between lactococcal plasmid pTR2030 and a virulent bacteriophage.

The conjugative plasmid pTR2030 confers bacteriophage resistance to lactococci by two independent mechanisms, an abortive infection mechanism (Hsp+) and a restriction and modification system (R+/M+). pTR2030 transconjugants of lactococcal strains are used in the dairy industry to prolong the usefulness of mesophilic starter cultures. One bacteriophage which has emerged against a pTR2030 transconjugant is not susceptible to either of the two defense systems encoded by the plasmid. Phage nck202.50 (phi 50) is completely resistant to restriction by pTR2030. A region of homology between pTR2030 and phi 50 was subcloned, physically mapped, and sequenced. A region of 1,273 bp was identical in both plasmid and phage, suggesting that the fragment had recently been transferred between the two genomes. Sequence analysis confirmed that the transferred region encoded greater than 55% of the amino domain of the structural gene for a type II methylase designated LlaI. The LlaI gene is 1,869 bp in length and shows organizational similarities to the type II A methylase FokI. In addition to the amino domain, upstream sequences, possibly containing the expression signals, were present on the phage genome. The phage phi 50 fragment containing the methylase amino domain, designated LlaPI, when cloned onto the shuttle vector pSA3 was capable of modifying another phage genome in trans. This is the first report of the genetic exchange between a bacterium and a phage which confers a selective advantage on the phage. Definition of the LlaI system on pTR2030 provides the first evidence that type II systems contribute to restriction and modification phenotypes during host-dependent replication of phages in lactococci.

Amino Acid Sequence↗
PubMed1991

An initial assessment of the cost and utilization of the Integrated Academic Information System (IAIMS) at Columbia Presbyterian Medical Center.

The concept of "one stop information shopping" is becoming a reality at Columbia Presbyterian Medical Center (CPMC). The goal of our effort is to provide access to university and hospital administrative systems as well as clinical and library applications from a single workstation, which also provides utility functions such as word processing and mail. Since June 1987, CPMC has invested the equivalent of $23 million dollars to install a digital communications network that encompasses 18 buildings at seven geographically separate sites and to develop clinical and library applications that are integrated with the existing hospital and university administrative and research computing facilities. During June 1991, 2425 different individuals used the clinical information system, 425 different individuals used the library applications, and 900 different individuals used the hospital administrative applications via network access. If we were to freeze the system in its current state, amortize the development and network installation costs, and add projected maintenance costs for the clinical and library applications, our integrated information system would cost $2.8 million on an annual basis. This cost is 0.3% of the medical center's annual budget. These expenditures could be justified by very small improvements in time savings for personnel and/or decreased length of hospital stay and/or more efficient use of resources. In addition to the direct benefits which we detail, a major benefit is the ease with which additional computer-based applications can be added incrementally at an extremely modest cost.

Academic Medical Centers↗
PubMed1991

[Estimation of alcohol-related deaths in France in 1985].

The number of deaths attributable to alcohol in France during 1985 has been estimated from national death statistics, and from records attributable risks for each disease related to alcohol. The attributable risks for alcohol by sex and by disease were computed from the 1974 survey by the Institut Français d'Opinion Publique of a national sample of 981 adults on consumption of alcohol, and from the relative risk of death for alcohol drinkers estimated from epidemiological studies. The total number of deaths attributable to alcohol in the population aged 20 or more was 52,000 in 1985 (44,500 men and 7,500 women). Half of these deaths occurred before age 65. Nine percent of the overall mortality was attributable to alcohol (3 percent for women and 16 percent for men). This proportion was 28 percent for men between ages 45 and 64. Among these 52,000 deaths, 14,000 were due to liver cirrhosis or alcoholic psychosis, 16,500 to cancer, mainly from oral cavity, pharynx, larynx, esophagus, or liver, 8,900 to external causes of injury, 9,050 to cardiovascular disease, 550 to pneumonia, and 3,000 to ill-defined diseases.

Accidents, Traffic↗
PubMed1991

[When is a difference statistically significant?].

From a very simple example (8 deaths observed in one group verus 2 in the other), we explain in details how to determine whether a difference is statistically significant. The arbitrariness of the 5% limit used to conclude that a difference is significant, is discussed. The difference between a one-sided and a two-sided situation is described in an appendix.

Humans↗
PubMed1990

Overall mortality and cancer mortality around French nuclear sites.

Higher than expected mortality from leukaemia has been observed in the population under age 25 living around Sellafield and Dounreay, nuclear reprocessing plants in the United Kingdom. We report the results of a similar study for the population residing around nuclear sites in France. The number of leukaemia deaths was 58, comparable to the 62 in control areas, and slightly less than the 67 expected from national mortality statistics. Twelve deaths due to Hodgkin's disease were observed around nuclear sites; this is about twice the number of Hodgkin's deaths observed in control areas and twice the number expected from national mortality statistics. This observation must, however, be interpreted in light of the fact that several causes of deaths were studied, increasing the play of chance.

Adolescent↗
PubMed1990

Overview of available data on diet and cancer mortality in France.

We are reasonably sure today that diet plays an important role in the etiology of many common types of cancer, although the mechanisms and the relevant components of the diet have not yet been clearly identified. Data on the temporal and geographical variations of diet, and of cancer mortality, are presented here for France. There were important modifications in the dietary habits of the French population between 1950 and 1985. The consumption of bread and potatoes went down by a factor 2, and alcohol consumption decreased by 20%. Simultaneously, increases varying between 50% and 100% were observed for butter, fish, fruits and vegetables; the consumptions of pork meat, oil, and margarine were more than doubled; and lastly the consumption of poultry went up by a factor 3.5, and cheese or yogurt by a factor 4.5. The variations between regions for France are also very large. The largest increases in cancer mortality between 1950 and 1985 were observed for mouth and pharynx, both in males and females, and for lung cancer in males. The largest geographical variations were observed for mouth and pharynx, for esophagus, and for stomach. For these sites, the highest rates were observed in Brittany. In our present state of knowledge on the relation between diet and the risk of cancer, we cannot reliably attribute the variations in cancer mortality to specific dietary habits.

Adult↗
PubMed1990

Prolactin response to low-dose haloperidol challenge in schizophrenic, non-schizophrenic psychotic, and control subjects.

Haloperidol was administered IV to 46 male psychotic inpatients and 28 male control subjects. A two-way analysis of covariance, with age as the covariate, revealed that DSM-III schizophrenics (n = 27) had a lower prolactin response to haloperidol than did the controls (n = 28). There were no significant differences between the prolactin responses in schizophrenics, patients with affective disorders (n = 7), and those with other psychoses (n = 12), which included patients with paranoia, schizophreniform, schizoaffective disorder, and atypical psychoses. These findings support the proposition that tuberoinfundibular dopaminergic dysfunction may occur in certain patients with DSM-III schizophrenia.

Adult↗
PubMed1990

Risk factors for breast cancer according to age at diagnosis in a French case-control study.

In a French case-control study of 1010 women with breast cancer and 1950 controls with nonmalignant disease, the variations of the effects of 8 risk factors for breast cancer as a function of age at diagnosis, were analysed by tests of homogeneity and trend. The risks associated with a late age at first full-term pregnancy and with nulliparity were different between age-groups (test of homogeneity: p = 0.03), and the highest risks for these two factors were observed in women 45-54 years old. The risks associated with Quetelet index were also found to vary with age at diagnosis (test for trend: p = 0.008). A high Quetelet index decreased the risk of breast cancer in the younger age-groups; this decrease of risk became progressively less important with advancing age, and no such effect was found in the oldest age-group. Inverse results were observed for a tall stature (test for trend: p = 0.04): a tall stature increased the risk of breast cancer in the younger age-groups, and the figures suggested a reverse effect in the oldest group. No large variation with age was found for the effects of age at menarche, history of breast cancer death in mother or sisters, prior biopsy for benign breast disease, and weight. In conclusion, the relative importance of certain risk factors for breast cancer is closely related to age at diagnosis. Nulliparity and a late age at first birth appear to be major risk factors only for middle-aged women, whereas a low Quetelet index and a tall stature appear to increase the risk of breast cancer only for younger women.

Adult↗
PubMed1990

Nucleotide sequence and distribution of the pTR2030 resistance determinant (hsp) which aborts bacteriophage infection in lactococci.

The lactococcal plasmid pTR2030 encodes resistance to bacteriophage attack via two mechanisms, an abortive-infection mechanism, designated Hsp, and a restriction and modification system. We present the complete sequence of the hsp structural gene. The gene is 1,887 base pairs in length and encodes a protein with a predicted molecular mass of 73.8 kilodaltons. The upstream region was cloned in a promoter-screening vector and shown to direct the constitutive expression of the cat-86 gene. An internal probe was used to determine the distribution of the hsp sequence in industrially significant lactococcal strains and to evaluate its relatedness to another lactococcal plasmid implicated in an abortive-infection-type mechanism, pNP40. No homology was detected, suggesting that this gene is not widely distributed in lactococci. Therefore, there are at least two independent abortive-infection genotypes in lactococci.

Amino Acid Sequence↗
PubMed1990

Cloning, expression, and sequence determination of a bacteriophage fragment encoding bacteriophage resistance in Lactococcus lactis.

A number of host-encoded phage resistance mechanisms have been described in lactococci. However, the phage genome has not been exploited as a source of additional resistance determinants. A 4.5-kb BamHI-HindIII fragment of phage nck202.50 (phi 50) was subcloned in streptococcus-Escherichia coli shuttle plasmid pSA3 and introduced into Lactococcus lactis NCK203 and MG1363 by protoplast transformation. This cloned phage fragment directed a bacteriophage resistance phenotype designated Per (phage-encoded resistance). Both phi 50 and a distantly related phage, nck202.48 (phi 48), formed small plaques on strain NCK213 at a slightly reduced efficiency of plaquing on the Per+ host. The per locus was further reduced to a 1.4-kb fragment through in vitro deletion analysis. The 1.4-kb fragment was sequenced, and the Per phenotype was found to be associated with a ca. 500-bp region rich in direct and inverted repeats. We present evidence that the Per region contains a phage origin of replication which, in trans, may interfere with phage replication by titration of DNA polymerase or other essential replication factors. It was demonstrated that the Per+ phenotype is not a result of reduced adsorption or action of a restriction and modification system. Per+ activity was not detected against six independent phages which were previously shown to be sensitive to the Hsp+ mechanism. The mutually exclusive resistance mechanisms could be combined to confer resistance to both types of phages (Hsp resistant and Per resistant) in a single host. This is the first description in lactococci of a phage resistance phenotype, other than superinfection immunity, originating from a lactococcal phage genome.

Amino Acid Sequence↗
PubMed1990

Comparison of antibody, antigen, and metabolite assays for hospitalized patients with disseminated or peripheral candidiasis.

Repeat serum samples from 22 patients with proven disseminated candidiasis and 42 with simple peripheral colonization were assayed for Candida antibodies by coelectrosyneresis, immunoprecipitation, and A and B immunofluorescence, for metabolites by D-arabinitol measurement, and for antigens by the mannan immunoassay and Cand-tec latex agglutination (mean number of samples tested, 2.5 per patient). For the antibody and metabolite assays, the results showed no statistical difference between the two groups. By contrast, the results of both antigen assays were positive for a significantly larger number of patients with disseminated candidiasis than of those with simple peripheral colonization. Results were regardless of whether the patients were neutropenic. They were not predictive of death. We calculated that the mannan antigen assay had 29% sensitivity and 97% specificity for the diagnosis of disseminated candidiasis. Likelihood ratios of a positive and a negative result of this test were 9.2 and 0.7, respectively, for this diagnosis. In the latex agglutination test, likelihood ratios were 2.5, 1.5, 1.6, and 0.3 when the test was positive for dilutions of 1/8, 1/4, and 1/2 and was negative, respectively.

Adolescent↗
PubMed1990

Review of randomized trials of homoeopathy.

The present review covers forty published randomized trials in which the results of a homoeopathic treatment were compared to those of a standard treatment, a placebo, or no treatment at all. These trials were identified after an extensive search through the literature. They cover a wide range of pathologies. Most were double-blind and used subjective and/or multiple endpoints. The median number of patients per group was 28. The analysis only included all the randomized patients in one third of the trials. In our opinion, the results do not provide acceptable evidence that homoeopathic treatments are effective.

Double-Blind Method↗
PubMed1989

Monoclonal antibody that inhibits biological activity of a mammalian ciliary neurotrophic factor.

Four monoclonal antibodies to a purified ciliary neurotrophic factor have been produced by a combination of in vivo and in vitro immunization of mouse lymphocytes. Three of the antibodies--3D12, an 1gA subtype, and 5G9 and 2B11, both IgM subtypes--bound to the single band on immunoblots of the purified factor. Of the four clones only one, 3D12, produced antibodies able to inhibit the biological activity of the neurotrophic factor in promoting the survival of ciliary neurones in dissociated culture.

Animals↗
PubMed1989

Characteristics of reproductive life and risk of breast cancer in a case-control study of young nulliparous women.

Between 1982 and 1985, a case-control study of nulliparous women, aged 25-45, was conducted to analyse the relationships between the risk of breast cancer and causes of nulliparity, including contraceptive methods. Fifty-one cases of breast cancer diagnosed less than 3 months before interview were matched with 95 controls on age at diagnosis, year of interview, and medical center. The causes of nulliparity related to female sterility or subfertility (mechanical or hormonal disorders) were not found to be associated with a significantly higher risk of breast cancer. The causes related to fertilization failure, i.e. no sexual partner, rare sexual intercourse (less than once per month), or partner with abnormal semen, were found to lead to an increased risk. Detailed analysis of contraceptive methods showed that the risk of breast cancer increased (p = 0.02) with a longer duration of use of barrier methods (withdrawal or condom). Conversely, the risk significantly decreased (p = 0.004) with a longer duration of use of non-barrier methods (oral contraceptives, IUD, cap, local spermicides, vaginal douche, safe period, or no method), i.e. methods allowing a direct exposure to human semen.

Adult↗