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Biomedical subjects

D M Jones

Publications and source records attributed to D M Jones.

At least 145 records · Page 8Linked to original sources
PubMed1989

Secondary cases of meningococcal infection among close family and household contacts in England and Wales, 1984-7.

To determine the incidence of secondary meningococcal infection in close family and household contacts of index patients and to review the efficacy of chemoprophylaxis the records of 3256 cases occurring from 1984 through 1987 were examined. Seventeen secondary cases (0.5%) of infection were identified among these groups. The median interval between index and secondary cases was seven weeks. Fourteen secondary cases occurred more than one week after the disease was diagnosed in the index case. Three secondary cases had not received chemoprophylaxis and in another case the infecting strain had acquired resistance to rifampicin. Prophylaxis for the close contacts of 10 out of 11 of the remaining index patients failed to fulfil all the criteria of an optimal regimen. Even after optimal chemoprophylaxis the medical practitioner and the family should be aware of the increased and prolonged risk of secondary meningococcal infection among close contacts of patients with the disease.

Adult↗
PubMed1989

The Stonehouse study: secretor status and carriage of Neisseria species.

The genetically determined inability to secrete the water-soluble glycoprotein form of the ABO blood group antigens into saliva and other body fluids is a recognized risk factor for meningococcal disease. During a community-wide investigation of a prolonged outbreak of disease due to a B15:P1.16 sulphonamide-resistant strain of Neisseria meningitidis in Stonehouse, Gloucestershire (the Stonehouse survey), the ABO blood group and secretor status of almost 5000 residents was determined. The proportion of non-secretors in the Stonehouse population was significantly higher than the proportion of non-secretors among blood donors in the South West Region and in England generally. Seven of 13 Stonehouse residents with meningococcal disease who were tested were found to be non-secretors, a high proportion. The outbreak in Stonehouse cannot be explained solely in terms of the increased proportion of non-secretors. There was no clear correlation between the proportions of non-secretors in different areas within the town and the incidence of cases of meningococcal disease. Carriers of meningococci, whether outbreak or other strains, were not more likely to be non-secretors. The reasons why non-secretors are more susceptible to meningococcal disease remain to be determined, but they do not appear to be related to carriage of meningococci.

ABO Blood-Group System↗
PubMed1989

Recruitment of a penicillin-binding protein gene from Neisseria flavescens during the emergence of penicillin resistance in Neisseria meningitidis.

Non-beta-lactamase-producing, penicillin-resistant strains of Neisseria meningitidis produce altered forms of penicillin-binding protein 2 that have decreased affinity for penicillin. The sequence of the penicillin-binding protein 2 gene (penA) from a penicillin-resistant strain of N. meningitidis was compared to the sequence of the same gene from penicillin-sensitive strains and from penicillin-sensitive and penicillin-resistant strains of Neisseria gonorrhoeae. The penA genes from penicillin-sensitive strains of N. gonorrhoeae and N. meningitidis were 98% identical. The gene from the penicillin-resistant strain of N. meningitidis consisted of regions that were almost identical to the corresponding regions in the penicillin-sensitive strains (less than 0.2% divergence) and two regions that were very different from them (approximately 22% divergence). The two blocks of altered sequence have arisen by the replacement of meningococcal sequences with the corresponding regions from the penA gene of Neisseria flavescens and result in an altered form of penicillin-binding protein 2 that contains 44 amino acid substitutions and 1 amino acid insertion compared to penicillin-binding protein 2 of penicillin-sensitive strains of N. meningitidis. A similar introduction of part of the penA gene of N. flavescens, or a very similar commensal Neisseria species, appears to have occurred independently during the development of altered penA genes in non-beta-lactamase-producing penicillin-resistant strains of N. gonorrhoeae.

Acyltransferases↗
PubMed1989

Rotaviral diarrhoea and its treatment in a foal.

A severely dehydrated foal with a history of acute diarrhoea was presented to Massey University for treatment. Rotavirus was demonstrated in the faeces by electron microscopy. The failure to detect other pathogens suggested that rotavirus was the primary aetiological agent. Successful treatment of this case is described and the principles of treatment for diarrhoea, particularly fluid therapy, are reviewed. Antibodies to rotavirus were detected in the sera of nine mares and their foals on the stud that referred the case, indicating that rotaviral infection was probably endemic.

Journal Article↗
PubMed1989

Inhibitors of rat renin and their use in experimental hypertension.

Hydroxy-ethylene dipeptide analogues (Leu[CH(OH)-CH2]Leu and Leu[CH(OH)-CH2]Val) of human substrate peptides are potent in vitro inhibitors of rat renin with IC50 values as low as 0.8 nmol/l. When given to renal hypertensive rats they lower blood pressure and suppress both plasma renin and angiotensin II. There was a divergence between the rapid rebound of renin and blood pressure which remained suppressed.

Animals↗
PubMed1989

Cross-modal, auditory-visual Stroop interference: a reply to Cowan and Barron (1987).

This series of experiments was performed to verify Cowan and Barron's (1987) reported effect of auditory color-word interference on a visual Stroop task. Extant theory predicts effects of irrelevant speech on visual memory tasks involving immediate, ordered recall of the items. Interference between the two sources of information (visual and auditory) is assumed to be located at the phonological store component of the articulatory loop. Perceptual tasks such as the Stroop task, which do not require use of the articulatory loop for rehearsal purposes, should not be similarly susceptible. The present data fail to replicate Cowan and Barron's findings, and are thus consistent with contemporary theory.

Adult↗
PubMed1988

Diagnosis of Meleney's synergistic gangrene.

A retrospective and comparative study of 127 case reports of Meleney's postoperative progressive synergistic gangrene and of 62 examples of postoperative amoebic skin gangrene, showed that these two entities were clinically indistinguishable and that therefore a purely clinical diagnosis of Meleney's gangrene could not be made. Furthermore, a critical appraisal of the bacteriological data indicated that a certain diagnosis of Meleney's gangrene cannot be provided by the clinical bacteriologist. Finally, the histological features were entirely non-specific thus precluding a definitive diagnosis by the histopathologist. If Meleney's entity cannot be diagnosed its existence becomes debatable. The alternative diagnosis of cutaneous amoebiasis is advanced for consideration. Several of the outstanding features of Meleney's progressive gangrene, hitherto unexplained, are better understood if Entamoeba histolytica is accepted as the prime cause rather than bacteria.

Entamoebiasis↗
PubMed1988

Anxiolytic effects of acebutolol and atenolol in healthy volunteers with induced anxiety.

Acebutolol (400 mg once daily), atenolol (100 mg once daily) and placebo were self administered to 12 healthy male volunteers in a double-blind crossover study. Each drug treatment was administered for 4 days so that subjects' plasma levels of the drug were at steady state. Subjects were tested on the 4th day. On each of the 3 test days subjects underwent an anxiety induction procedure involving both easy and difficult versions of the Stroop test and syntactic reasoning. Measures of state anxiety were taken during the difficult task, an easy version of the task and after a period of quiet relaxation. High, medium and low levels of anxiety corresponded to the three levels of task difficulty. Highly significant differences were exhibited in state anxiety between high, medium and low anxiety induction procedures with both Stroop test and syntactic reasoning. This was shown by highly significant main effects for task difficulty with both tasks. There was no significant anxiolytic action of either acebutolol or atenolol when compared to placebo (there were no drug effects or any interaction of drugs with task difficulty). There were no significant drug effects upon any of the cognitive test measures. Overall, there was no evidence of either anxiolysis or sedation with either of these two relatively hydrophilic drugs.

Acebutolol↗
PubMed1988

Type A behaviour and pressor response in a representative sample of middle-aged men.

The hypothesis that type A behaviour is associated with greater pressor response to stress was tested in a representative sample of 114 men aged 30-65 yr. Jenkins Activity Survey, Framingham and Bortner type A scores were related to blood pressure and heart rate under rest, serial reaction time, mental arithmetic, and noise conditions. Type A scores were modestly intercorrelated (r = 0.59 to r = 0.67). Type A scores were inversely related to age and resting systolic pressure and were independent of smoking history, social class, marital status, and task performance parameters. Type A scores were not related to pressor or heart rate response to stress under any of the stress conditions. These findings do not support the importance of physiological response as an explanation of the association between type A and heart disease.

Adult↗
PubMed1988

Control of an outbreak of group C meningococcal meningitis with a polysaccharide vaccine.

An outbreak of meningitis in Royal Air Force recruits due to Neisseria meningitidis Group C type PI, 2 gave the first opportunity for polysaccharide vaccine to be used for controlling such an outbreak in the U.K. The effect of the vaccine on an epidemic in a large recruit training centre was studied after chemoprophylaxis had failed. With the possible exception of one vaccinee, further cases did not arise among camp personnel. Vaccination was continued until the carriage rate of the epidemic strain among recruits leaving the camp had fallen from greater than 19 to less than 1%. Two persons who had only indirect contact with the camp developed the disease. Vaccination early in the course of such an outbreak appears to be a useful and practical method of limiting symptomatic infection but not acquisition of the epidemic strain.

Adolescent↗
PubMed1988

Campylobacter pylori infection in children.

Two children with antral nodular hyperplasia and active chronic gastritis associated with Campylobacter pylori are reported. The organism was observed by scanning electron microscopy and cultured from antral biopsies obtained at endoscopy from each patient. Anti-C. pylori IgG was detected in high titre in both patients together with serum IgM in one patient. Treatment with ampicillin and a bismuth preparation resulted in total resolution of symptoms. Repeated endoscopy with antral biopsy and culture, as well as the absence of acute inflammatory changes, confirmed the eradication of the organism. Correlation of positive bacteriological cultures and serological tests with the clinical improvement related to therapy supports a causative role for C. pylori in antral lymphoid hyperplasia and antral gastritis in children.

Adolescent↗