For the isolation of Streptococcus mutans, several selective media have been developed, of which Mitis-Salivarius Sucrose Bacitracin agar (MSB) is the most widely used (Gold et al., 1973). Recently, the Trypticase Yeast-Extract Cystine agar medium (TYC, de Stoppelaar et al., 1967) was modified into a selective medium for S. mutans, called Trypticase Yeast-Extract Cystine Sucrose Bacitracin (TYCSB, van Palenstein Helderman et al., 1983). The aim of this study was to compare the recovery of S. mutans from clinical samples on Mitis-Salivarius agar (MS), MSB, TYC, and TYCSB. Further, a new simple selective medium for S. mutans was introduced. This medium, called TSY20B, was supposed to have the same qualities as TYCSB, but its preparation is less laborious. One hundred eighty-five plaque and saliva samples from 37 subjects were plated on MS, MSB, TYC, and TYCSB, and 285 samples from 23 subjects were plated on TYCSB and TSY20B. All plates were incubated at 37 degrees C in a 91% N2, 5% CO2, 4% H2 atmosphere for five days. The S. mutans counts on TYC and TYCSB were significantly higher than on MS or MSB by almost a factor of 10. Seventy-seven percent of the samples gave higher S. mutans counts on TYCSB than on MSB. Especially, samples with high S. mutans d/g numbers gave lower S. mutans counts on MSB. These data clearly indicate that MSB agar is inhibitory for S. mutans and should not be used. An additional advantage of TYCSB over MSB agar is the possibility of distinguishing S. mutans serotypes d/g from other serotypes.(ABSTRACT TRUNCATED AT 250 WORDS)

The aim of this study was to determine the effect of an intensive antimicrobial treatment on the number of Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus/Actinomyces naeslundii, and the total Colony-forming Units (CFU) in plaque. The dentition of human volunteers was treated in a dental office with either chlorhexidine (5%) or stannous fluoride (8%). Following the office treatment with chlorhexidine, selected volunteers rinsed daily at home for seven or 49 days with chlorhexidine solution (0.2%), while another group flossed daily at home for seven days with dental floss impregnated with chlorhexidine. On days one, seven, 21, 35, and 49 after the local applications, we took saliva samples and plaque samples from fissures, smooth surfaces, and approximal areas. Chlorhexidine and stannous fluoride suppressed S. mutans and the Actinomyces species on all surfaces and in saliva. S. mutans on tooth surfaces was suppressed for approximately seven days and returned to the baseline level at day 21. A. viscosus/naeslundii was suppressed for more than seven days on the teeth. S. sanguis and the total CFU returned to the baseline level within seven days on all surfaces and in saliva. Rinsing or flossing with chlorhexidine suppressed S. mutans during the period of time that these supplements were used. Brushing for seven days with chlorhexidine gel (1%) without a preceding intensive chlorhexidine treatment had virtually no effect on S. mutans in approximal areas and in saliva, but suppressed S. mutans in fissures and on smooth surfaces.

Localized areas of the dentition in human volunteers were treated once with chlorhexidine or iodine. Plaque samples taken from the experimental surfaces were analyzed for the number of Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus and the total viable counts. Chlorhexidine and iodine strongly suppressed S. mutans and A. viscosus, but S. sanguis was much less affected. A. viscosus returned to its original level within 7 days after chemotherapy. S. mutans returned much slower to its pretreatment level. In fissures and restoration margins, S. mutans was still significantly suppressed 21 days after chlorhexidine application.

Background-The incidence of coeliac disease varies internationally. Ains-To assess the incidence of childhood coeliac disease in The Netherlands and to study the clinical features and the presence of associated disorders.

Background: The Western Cape province has the highest documented lifetime prevalence of common mental disorders in South Africa. To ensure the efficient, equitable and effective distribution of current resources, there is a need to determine the profile of patients requiring psychiatric admission.Aim: To describe patients admitted to the acute adult admissions unit at Lentegeur Hospital.Setting: Lentegeur Psychiatric Hospital is situated in Mitchells Plain, Cape Town, and serves about 1 million people from nearby urban and rural areas.Methods: This retrospective study involved an audit of all patients (18–60 years of age) admitted between 01 January 2016 and 30 June 2016. The clinical records of 573 adult patients were examined.Results: The median age of the cohort was 29 years. Most patients (63%) were educated to the secondary level. Only 12% of the patients were employed, and 37% received disability grants. More than 90% of the patients presented with psychotic symptoms. Of these, 28% presented with a first-episode of psychosis. Of all patients, 20% were referred with manic symptoms and 7% with depressive symptoms. Many patients (62%) used substances concurrently in the period leading up to admission. Significantly more males (73%) used substances compared to females (38%). Cannabis was the most widely used substance (51%), followed by methamphetamine (36%). Recent violent behaviour contributed to 37% of the current admissions. A total of 70 patients (13%) tested positive for human immunodeficiency virus (HIV), and 49 (9%) tested positive for syphilis.Conclusion: Substance use and a history of violence contributed to admissions in this population.

Summary Systemic toxicity is usually the dose-limiting factor in cancer chemotherapy. Regional chemotherapy is therefore an attractive strategy in the treatment of liver metastasis. Two ways of regional chemotherapy, hepatic artery infusion (HAI) and isolated liver perfusion (ILP), were compared investigating the difference in toxicity with tissue and biofluid concentrations of mitomycin C (MMC). In wistar derived WAG rats the maximally tolerated dose of mitomycin C via HAI was 1.2 mg kg-'. Body weight measurements after HAI with doses higher than 1.2 mg kg-' suggest both an acute and delayed toxic effect of mitomycin C since the time weight curves were triphasic: a rapid weight loss, a steady state and a second fall in weight phase. These rats died due to systemic toxicity. ILP with 4.8 mg kg-' was associated with no signs of systemic toxicity and only transient mild hepatotoxicity. ILP with 6.0 mg kg-' was fatal mainly due to hepatic toxicity. The four times higher maximally tolerated dose in ILP resulted in a 4-5 times higher peak concentration of mitomycin C in liver tissue, while the plasma concentration remained significantly lower than in the HAI treated rats. In the tumour tissue a 500% higher concentration of mitomycin C was measured in the ILP with 4.8 mg kg-' than in HAI with 1.2 mg kg-' treated rats. We demonstrated that when mitomycin C was administered by ILP a 400% higher dose could be safely administered and resulted in a five times higher tumour tissue concentration. In view of the steep dose-response curve of this alkylating agent this opens new perspectives for the treatment of liver metastasis.The liver is a major site of metastatic spread of primary colorectal cancer; in as many as 30% of the patients it is also the sole site of initial tumour recurrence . At the time of operation for the primary tumour approximately 5% of patients with colorectal cancer have resectable liver metastases (Foster & Lundy, 1981). Another 5% will develop resectable metastases confined to the liver after resection of the primary tumour (Foster & Berman, 1977;Adson, 1983). These patients can be cured by surgery and a 5-year survival rate of about 35% can be achieved (Foster & Lundy, 1981;Adson et al., 1984;August et al., 1985;Iwatsuki et al., 1986).Unfortunately, in the majority (75%) of the patients with colorectal cancer metastases confined to the liver, the tumour is not resectable. These patients are eligible for locoregional therapies. The rationale of regional administration of chemotherapy is based on the concept of achieving a high local concentration, while minimising systemic drug levels and, accordingly, reducing dose limiting systemic side-effects (Collins, 1984). For most chemotherapeutic agents steep dose-response curves can be demonstrated. Therefore, high drug concentrations are important for both sensitive and resistant tumour cells. For resistant cells extremely high exposure is required for adequate cell kill (Slee et al., 1987;Kuppen et al., 1988).Exploiting high extraction ratios of the fluoro...

Various carboxylic acids from bacterial fermentation could easily be separated by isotachophoresis. The analyses were performed on an LKB 2127 Tachophor, and under the conditions used the minimum amount of sample that could be quantitatively estimated was approximately 0.1 nmol. The reproducibility of the method was good (ca. 5%). The time of analysis using a 23-cm column was 12 min. No pretreatment of the samples was required.

Little information is available on the production of acids in dental plaque of known microbial composition. In the present experiment monocarboxylic and lactic acids were assayed in rat dental plaque before and after exposure to sucrose. Actinomyces viscosus Nyl and Streptococcus sanguis Ny101 were the major organisms in the plaque in two groups of rats. Streptococcus mutans T2 was inoculated in one group of the rats where it accounted for 20% of the total viable counts. Organic acids in the plaque were determined using isotachophoresis and adjusted to the size of the samples as determined by DNA. Formic, acetic, and lactic acids were found to be the predominant organic acids in the S. mutans and the control plaques. Sucrose administration was followed by a change to homolactic fermentation of the plaque in both groups. The lactic acid peak at 5 min after sucrose exposure was significantly higher in the S. mutans group than in the control group. More caries was found in the rats harboring S. mutans than in the other animals. The results suggest that rapid production of lactic acid following sucrose intake by the host is a main factor in the cariogenicity of S. mutans.