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Biomedical subjects

H Smith

Publications and source records attributed to H Smith.

At least 595 records · Page 33Linked to original sources

The intracellular survival and growth of gonococci in human phagocytes.

In reassessment of previous tests for intracellular survival, results have been confirmed and additional evidence obtained indicating that some gonococci can survive and multiply in human phagocytes. Use was made of the ability of penicillin to penetrate phagocytes and to kill only actively growing organisms. In microscopic counts on 33 urethral exudate smears, an average of 49% of gonococci were associated with polymorphonuclear phagocytes. The organisms were unevenly distributed amongst the phagocytes, with most cells uninfected and some containing large numbers. Many phagocytes also remained uninfected in tests in vitro with low gonococcal inocula although experiments with large inocula showed that most phagocytes could ingest gonococci. It is proposed that ingestion of one gonococcus may stimulate the phagocytes to take up more. Phagocytes were killed and disintegrated after ingesting large numbers of gonococci and similar effect in vivo may be responsible for the large clumps of organisms seen in urethral exudate. These results underline the probable importance in the pathogenesis of gonorrhoea of intracellular survival in phagocytes.

Blood Bactericidal Activity↗

Phenotypically determined resistance of Neisseria gonorrhoeae to normal human serum: environmental factors in subcutaneous chambers in guinea pigs.

Some gonococci obtained from human urethral exudate or from subcutaneously implanted chambers in guinea pigs show a resistance to killing by human serum which is lost on sub-culture in vitro after a few generations. The environmental factors which may influence the phenotypic expression of resistance to serum killing were investigated in guinea pig chambers and in chamber fluid in vitro. The redox potential in chambers before and after infection was lower than that of heart blood but conditions were not anaerobic; H2O2 increased the redox potential but did not decrease gonococcal serum resistance. The chambers were slightly alkaline before and after infection. When the concentration of glucose (depleted in infected chambers by the abundant polymorphonuclear cells) was restored to excess, the serum resistance of the gonococci was unaffected. Concentrations of free amino acids in chambers changed little during infection. Gonococci adapted to growth in chambers and subsequently rendered serum-sensitive by growing once on agar reverted to serum-resistance after 0.5 to 1 h incubation in chamber fluid in vitro at 37 degrees C but not at 25 degrees C or 4 degrees C. After 16 to 24 h growth at 37 degrees C, resistance was again lost. The reversion to serum resistance did not occur in a complex laboratory medium. Examination of the chamber fluid after growth of gonococci in vitro showed depletion of lactate, glutamine and proline.

Acetates↗

Serum bilirubin: a prognostic factor in primary biliary cirrhosis.

We followed up 55 patients with proven primary biliary cirrhosis for several years or until death. A graph of the level of serum bilirubin versus time that was constructed for each patient shows an initial period of variable length in which the serum bilirubin level remained constant. This was followed by a period of rapid rise in serum bilirubin which culminated in the patient's death. Whenever two successive serum bilirubin values taken six months apart exceeded 34 mumol/l (2.0 mg/dl) the patient had entered a late phase of disease and lived an average of 49 months. Ninety-five per cent confidence limits on survival time were 32-74 months. If two successive six month bilirubin values exceeded 102 mumol/l (6.0 mg/dl), calculated survival time was 25 months, and if two successive six month bilirubin values exceeded 170 mumol/l (10.0 mg/dl), survival time was 17 months. Fifteen of the 41 living patients had two consecutive serum bilirubin levels greater than 34 mumol/l (2.0 mg/dl). However, the slope of the rising bilirubin in the living patients is only 35 mumol/l/yr (1.5 mg/dl/yr) compared with 42 mumol/l/yr (2.5 mg/dl/yr) in the dead patients. This means that patients with this disease not may be living considerably longer.

Adult↗

Acute inflammation following intraperitoneal injection of antigen into actively sensitised rats.

Rats actively sensitised to bovine serum albumin (BSA) in Freund's complete adjuvant were challenged by intraperitoneal injection of BSA. By washing out the peritoneal cavities at different times it was possible to divide the changes that occurred into two phases. The first was characterised by the release of histamine and slow reacting substance of anaphylaxis (SRS-A) with an associated extravasation of plasma proteins. The second phase was characterised by an increase in neutrophilic polymorphonuclear cells in the peritoneal cavity. Extracellular enzyme activites were also investigated. The kinetics of these events were studied and are discussed in terms of the possible mechanisms involved.

Animals↗

Effects of drugs on the acute inflammation following intraperitoneal injection of antigen into actively sensitised rats.

When actively sensitised rats were injected intraperitoneally with antigen, the local reaction that ensued can be divided into two phases: an immediate reaction characterised by histamine and SRS-A release with an associated extravasation of plasma proteins, and a later reaction involving infiltration of neutrophilic polymorphonuclear leucocytes. When the immediate reaction was modified by BRL 10833 (which inhibits histamine release from rat mast cells and reduces extravasation of plasma proteins), there was no reduction in neutrophil infiltration. FPL 55712, an SRS-A antagonist, also failed to inhibit neutrophil infiltration. The beta-adrenoreceptor stimulants isoprenaline and salbutamol reduced neutrophil infiltration. Isoprenaline inhibited the extravasation of plasma proteins when given before antigen, but even when administered to rats after antigen, when extravasation was complete, it still inhibited neutrophil infiltration. Propranolol reversed isoprenaline-induced inhibition of neutrophil infiltration.

Adrenergic beta-Agonists↗

The influence of left ventricular late diastolic filling on the A wave of the left ventricular pressure trace.

To study the influence of left ventricular (LV) late diastolic filling on the A wave of the LV pressure, simultaneously recorded echocardiographic LV dimensions and high-fidelity LV pressure measurements were taken in 24 patients. Group 1 comprised eight patients without LV hypertrophy (LVH) and LV end-diastolic pressure (LVEDP) less than or equal to 13 mm Hg. Group 2 comprised 16 patients with LVH secondary to aortic stenosis, idiopathic hypertrophic subaortic stenosis, or hypertension and increased LVEDP. Patients in group 2 had significantly thicker left ventricles, decreased mitral E-to-F slopes, and larger A waves in the LV pressure curve. On the basis of end-diastolic chamber stiffness, we divided group 2 into two populations: 12 patients (group 2A) with end-diastolic chamber stiffness similar to that in group 1, and four patients (group 2B) with markedly elevated end-diastolic chamber stiffness. Patients in group 2A had a larger atrial contribution to LV filling than those with markedly abnormal stiffness (group 2B). Therefore, in LVH an increased A wave in the LV pressure may be related to either elevated end-diastolic chamber stiffness or augmented left atrial volume transport.

Adult↗

Amino acids in bipolar affective disorders: increased glycine levels in erythrocytes.

The authors measured the concentrations of 20 amino acids in the erythrocytes and plasma of 13 female bipolar patients and 10 female normal controls. The concentration of glycine in the erythrocyte was significantly elevated in the patient group. No differences were present in the plasma. Preliminary findings indicate that the high glycine levels were present in patients who were depressed, manic, or in remission and were unaffected by electroshock therapy.

Adult↗

The trapped temporal horn: a trap in neuroradiological diagnosis.

Although the advent of computerized cranial tomography (CT) has decreased the number of pneumoencephalograms performed for the diagnosis of hydrocephalus and lesions of the posterior fossa, brain stem, and ventricles, there are some patients in whom pneumoencephalography should still be done because it adds valuable information to that obtained with CT. When the temporal horn becomes obstructed, the choroid plexus and ependymal surface "upstream" from the obstructing mass continue to produce cerebrospinal fluid (CSF). The temporal horn can thus enlarge enough to appear as a mass on CT because of its reduced x-ray attenuation coefficient. Pneumoencephalography is effective in this situation because air will flow past a mass that obstructs CSF and because the ventricular system dilates during pneumoencephalography. When pneumoencephalography is used in a patient with a trapped temporal horn, the partially trapped horn may enlarge approximately 24 hours later. With that precaution in mind, the neurosurgeon should find pneumoencephalography to be a useful adjunct to CT in delineating the cause of a trapped temporal horn. In the three patients reported here CT had indicated a unilateral trapped temporal horn; pneumoencephalography confirmed that finding and demonstrated both the location and the nature of the lesion. One patient had a Grade II astrocytoma fungating into the atrium of the right lateral ventricle, one had a mass extending into the right ventricle from the medial and superior ventricular wall with nodular encroachment on the ventricle, and one had a meningioma in the atrium of the right lateral ventricle.

Aged↗

Mortality rates of persons entering methadone maintenance: a seven-year study.

An analysis of all deaths occurring over a 79-month period in patients enrolled in methadone maintenance (MM) revealed an overall mortality rate of 20/1,000. Over a similar period 510 persons were discharged from MM. Follow-up able to be performed in 80% revealed at least 22 deaths to have occurred subsequent to discharge. Survival curves calculated on the basis of these data indicate that even under the best possible assumption, age adjusted mortality rates of heroin addicts are not only above the national mean but are one and a half times that of the population in the community surrounding the clinic. None of the deaths could be directly attributed to methadone. Alcohol was prominent in 60% of all deaths, being responsible for 89% of medical deaths and present in 35% of violent deaths. These findings emphasize the persistent risk associated with heroin addiction as well as the role of alcoholism in the production of excessive mortality.

Adult↗

Cancer in universal and left-sided ulcerative colitis: factors determining risk.

A retrospective study of 267 patients with ulcerative colitis admitted to The Mount Sinai Hospital during the period 1960--1976 revealed 26 (9.7%) with adenocarcinoma of the colon. Twenty-one cases of colorectal cancer were observed among 158 patients with universal colitis (13%), and 5 occurred among 109 patients with left-sided disease (5%). Patients with left-sided disease tended to develop cancer at least a decade later than patients with universal disease. The median duration from onset of colitis to diagnosis of cancer was 20 yr for those with universal colitis, and 32 yr for those with left-sided colitis. The decade incidence of colorectal carcinoma increased from 0.4% in the first decade to 7.4% in the second, 15.9% in the third, and 52.6% in the fourth decade of follow-up. The estimated cumulative probability of developing cancer reached 34% at 30 yr and 64% at 40 yr. Cancer risk was positively correlated with duration and anatomic extent of colitis, but did not appear to be increased by early age at onset of disease.

Adenocarcinoma↗

Incidence of non-cholera vibrios in Hungary.

In the period 1971 to 1976, 200 non-cholera vibrio (NCV) strains were isolated in Hungary; 18 of the cultures were derived from 34 729 faecal and 182 from 237 surface water samples. Ninety-two strains belonged to the Heiberg-Smith group I and 108 to group II. Two strains failed to give the string test and 3 were pteridine resistant. The strains were classified into 48 serotypes according to Smith's system. Faecal NCV strains belonged to serotypes 46 and 328; these serotypes did not occur in water. Of the 18 faecal strains 13 were isolated from 18 048 persons who had travelled in cholera-infected areas, and 5 strains from persons who had never left Hungary (2 from 4559 patients with diarrhoea and 3 from 6061 healthy individuals). These data indicate that although NCV are present in the environment, they play an insignificant role in enteric infections in Hungary.

Bacterial Toxins↗