Prevalence and socioeconomic determinants of dental sealant use among schoolchildren in Saudi Arabia.

There are no published research reports on the prevalence of dental sealant use in children in Saudi Arabia. This study determined the prevalence and socioeconomic indicators of dental sealant use on the permanent molars of a stratified random sample of schoolchildren in Jeddah. A basic oral screening survey of students was conducted by dentists and a self-administered questionnaire was completed by parents. The prevalence of dental sealant use among 1668 3rd and 8th grade students was 9.0%. Students who attended public schools and those who had fathers with lowerthan high-school education were less likely to have sealants. A stepwise logistic regression model showed that socioeconomic status of school district, family's monthly income, family's type of home, having medical insurance and receiving government financial support were significantly associated with sealant use. Efforts to increase sealant use and to reduce socioeconomic disparities appear warranted in the light of high rates of dental disease.

Collaborative needs assessment and systems development in Alabama: Process and products.

This article describes the implementation of a collaborative project and its results, involving a department of maternal and child health (DMCH) in a school of public health and a state department of public health. The state received a federal grant to enhance systems development for women and children. Adequate information regarding the existing system of health care was lacking. The state contracted with the DMCH for assistance in designing and conducting a needs assessment, whose purpose was to (1) identify strengths and weaknesses in the state system of care, (2) provide baseline information for targeting resources and measuring change, and (3) initiate an on-going process of assessment and evaluation of need. The DMCH collected data about financial and nonfinancial barriers to care from state-level health agency and organization experts, county-level service personnel, and consumers. The contributions to understanding the needs of the state offered by the information garnered in the three surveys helped the state in setting immediate and long-range objectives. The presence of the school of public health and the focus of its particular DMCH on assisting state agencies provided an atmosphere in which the state could ask for assistance and the university could respond in a way that was useful and relevant to the state's needs. Medical Subject Headings (MeSH): assessment, health planning, health priorities, interprofessional relations, program planning, public health.

Lantadene A toxicity in sheep. A model for cholestasis.

Liver injury occurred after sheep were injected intravenously with the triperpene acid lantadene A, the toxic principle of the tropical plant Lantana camara. A single dose of 1--3 mg/kg of the compound caused mild hepatocellular injury characterized by transient rises in serum enzymes, with or without hyperbilirubinaemia. Higher doses resulted in hepatic necrosis. When low doses of the triterpene were given repeatedly over several days a cholestatic syndrome developed which appeared identical with that caused by consumption of the plant. This is a disease model which may be of value in experimental studies of intrahepatic cholestasis. This study provides evidence that lantadene A is hepatotoxic and does not require metabolism in the alimentray tract for toxicity in sheep.

Toxicity of miserotoxin and its aglycone (3-nitropropanol) to rats.

The toxicity of miserotoxin (3-nitro-1-propyl-beta-D-glucoside) and its aglycone, NPOH, were compared in rats. Miserotoxin, a component of certain legumes, was relatively innocuous given orally (LD50 greater than 2.5 g/kg) but NPOH (LD50 = 77 mg/kg) was at least 10 times more toxic. Miserotoxin was readily absorbed from the upper regions of the digestive tract but the degree of gastrointestinal hydrolysis was small. The low toxicity of miserotoxin was attributed to a low level of microbial hydrolysis. NPA was not detected in the gastrointestinal tract during miserotoxin digestion. A simple method for isolating miserotoxin by column chromatography is described.

Conversion of 3-nitropropanol (miserotoxin aglycone) to 3-nitropropionic acid in cattle and sheep.

The metabolism of intravenously administered 3-nitropropanol (miserotoxin aglycone) was examined in cattle and sheep using high-pressure liquid chromatography (HPLC) to determine nitrocompounds in plasma. 3-Nitropropanol (NPOH) showed a rapid rate of decay and simultaneously, 3-nitropropionic acid (NPA) was detected at comparable levels in plasma. In animals dosed with NPOH, the observed NPA decayed at a slower rate than NPOH. Nitrite levels in plasma were more closely related to NPA than to NPOH. Therefore, metabolism of NPOH is linked to NPA and this could provide a common basis for the toxicity of these compounds in cattle and sheep.

Absorption of 3-nitropropanol and 3-nitropropionic acid from the digestive system of sheep.

When 3-nitropropanol (NPOH) was injected into the rumen (30 mg/kg), abomasum (10 mg/kg) or small intestine (10 mg/kg) of sheep, it was rapidly absorbed and converted to 3-nitropropionic acid (NPA). The reticulo-rumen was the major site of absorption for the miserotoxin aglycone but the abomasum and the small intestine also had the capacity to absorb NPOH. When NPA was injected into different regions of the alimentary tract, the reticulo-rumen was also the major site of absorption. Absorption of NPA or NPOH from the small intestine was much more rapid than from the abomasum. Plasma levels of NPA and inorganic nitrite were higher after dosing with NPOH than with NPA indicating a more rapid rate of uptake of the aglycone.

Absorption of 3-nitropropanol (miserotoxin aglycone) from the compound stomach of cattle.

Miserotoxin, the toxic component of certain Astragalus spp. (Leguminosae), was rapidly hydrolyzed to 3-nitropropanol (NPOH) in the rumen of cattle dosed with timber milkvetch (A. miser var. serotinus). The aglycone showed a rapid rate of disappearance from the rumen with an average half-life of 1.24 h. In contrast to the passage of Co-EDTA, which showed an exponential rate of increase in the abomasum, NPOH was not detected in abomasal fluid collected from dosed cattle. Rapid absorption of NPOH from the rumen was shown by plasma levels of 3-nitropropionic acid (NPA) and inorganic nitrite, but conversion of NPOH to NPA was not observed to any significant extent in the rumen.

Use of 13C nuclear magnetic resonance spectroscopy for the evaluation of hepatic drug-metabolizing enzyme activity in perfused mouse livers.

Experiments were performed to determine whether the activity of hepatic drug-metabolizing enzymes could be estimated in intact livers by 13C NMR spectroscopy. 13C-labelled aminopyrine was administered to isolated perfused mouse livers and the rate of decline in the NMR signal arising from the drug was used to estimate the half-life of aminopyrine. The technique was sufficiently sensitive to discriminate between the enzyme activities in normal livers and in livers whose enzyme activity was enhanced by treatment with sodium phenobarbitone. It was also demonstrated that demethylation of aminopyrine was not impaired in perfused livers from mice infected with Plasmodium berghei.

Pharmacokinetics and absolute bioavailability of cyclosporin following intravenous and abomasal administration to sheep.

Cyclosporin A pharmacokinetics were studied following intravenous and abomasal dosing in an open, crossover study in healthy, merino ewes. Five different doses of cyclosporin A were dispersed in milk and administered into the abomasum through a surgically inserted fistula which simulates oral administration. Cyclosporin A was well tolerated. Whole blood concentrations of cyclosporin A were measured by HPLC and mean clearance (0.45 +/- 0.05 L h-1 kg-1), distribution volume (4.4 +/- 2.0 L kg-1), mean residence time (9.6 +/- 4.1 h) and half-life (12.1 +/- 3.1 h) were calculated cyclosporin A was excreted in urine or bile. Area under the curve increased proportionally with doses up to 26.3 mg kg-1, but was curvilinear above this dose. Abomasal bioavailability at 6.4 mg kg-1 was 0.26 +/- 0.09, and mean absorption time was 4.7 +/- 11.1 h. Considerable pharmacokinetic variability was observed, particularly after abomasal administration. Cyclosporin A pharmacokinetics in sheep lie within the values reported in man after renal, bone marrow and cardiac transplantation.

Trigonal-colonic anastomosis: a urinary diversion procedure in dogs.

Trigonal-colonic anastomosis for diversion of urine into the colon was performed in 12 clinically normal dogs and in 10 incontinent dogs with diseases of the urinary bladder or urethra. Dogs were studied from 1 to 30 months after surgery. The surgical procedure was technically satisfactory. Fifteen of 22 dogs were studied with intravenous urography, and only 1 case of hydronephrosis was found. Pyelitis was a common histopathologic finding in both groups of dogs. Pyelonephritis developed in 30% of dogs, regardless of duration of anastomosis. Glomerular filtration rate was reduced in all dogs studied, but renal failure was infrequent. Values for blood urea nitrogen and serum inorganic phosphorus were elevated due to intestinal recycling of nitrogenous products and phosphate. Electrolyte imbalances were not a problem, but gastrointestinal disturbances developed in 3 of the 10 diseased dogs. Six of 10 diseased dogs survived from 9 months to more than 3 years. Trigonal-colonic anastomosis appears to be a satisfactory salvage procedure for incontinent dogs with diseases of the urinary bladder or urethra that do not respond to other forms of therapy.

Current ideas on the pathophysiology and treatment of lantana poisoning of ruminants.

Lantana poisoning in ruminants results from the ingestion of toxic varieties of the plant Lantana camara, which contain the triterpene acids lantadene A and lantadene B. Poisoning results in intrahepatic cholestasis and the consequences of the liver injury include jaundice, photosensitisation and ruminal stasis. The decreased ruminal motility causes toxic material to be retained in the rumen and continuous absorption of toxins from the rumen maintains the disease. Lantana poisoning can best be treated by preventing further absorption of toxins. This can be achieved by giving a large quantity of activated charcoal into the rumen together with a large volume of a multiple electrolyte solution to stimulate ruminal motility and rehydrate the animal. Treatment for photosensitive dermatitis should also be given.

Vaccination as a possible means of preventing lantana poisoning.

The toxic triterpene acids lantadene A and lantadene B were isolated from Lantana camara and conjugated to bovine serum albumen or haemocyanin. The conjugates were emulsified with complete Freund's adjuvant and injected into sheep and cattle. Vaccinated animals produced antibodies against the toxic compounds. Cholestasis was less severe in vaccinated than in non-vaccinated sheep challenged with a toxic dose of lantana. The results indicated a mild protective effect of vaccination against the hepatotoxic effects of lantana toxins.

Cerebrospinal angiostrongyliasis in five captive tamarins (Sanguinus spp).

Four cotton-top tamarins (Sanguinus oedipus oedipus) and one emperor tamarin (S imperator subgrisescens) housed in a zoo became depressed, anorexic, paraparetic and eventually paralysed. The animals died within 5 days to 18 months of the appearance of clinical signs. Histological examination showed nonsuppurative and eosinophilic meningoencephalitis, and metastrongyle nematode larvae were found within subarachnoid spaces of all animals and within the spinal cord of one. Intact larvae with features consistent with Angiostrongylus cantonensis were recovered from the brain of one animal. This parasite is the classical cause of eosinophilic meningoencephalitis in many parts of the world and the diagnosis can be strongly suspected on clinical grounds. In endemic areas like south-east Queensland, protection of captive animals against infection with A cantonensis is a difficult balance between providing a stimulating, natural setting and eliminating potentially infectious definitive, intermediate and paratenic hosts. This is the first report of cerebrospinal angiostrongyliasis in tamarins and nonhuman primates in Australia.