Incisor trauma in an adolescent Arab population: prevalence, severity, and occlusal risk factors.

INTRODUCTION: Incisor trauma is a significant clinical problem in children and adolescents. The purposes of this study were to report on the prevalence and severity of incisor trauma in a large population-based sample of adolescent Kuwaiti residents in the early permanent dentition, to determine the ages of and reasons for the injuries, and to test for any effects of sex, incisor occlusion, and lip coverage on the prevalence of incisor trauma. METHODS: Presence and type of traumatic injury were scored according to the National Institute of Dental Research index in a population-based sample of 795 girls and 788 boys with a mean age of 13.24 years (SD 0.42). RESULTS: Trauma prevalence was higher (P < .001) in boys (19.3%) than in girls (9.7%), and in the maxilla (13.6%) than in the mandible (1.5%). Most (77.3 %) of the affected subjects had only 1 injured tooth, and most (83.7%) of the traumatized teeth were maxillary central incisors. A total of 90.3% of the injuries were unrepaired enamel or enamel/dentin fractures. The major reasons for the injuries were falls and blows indoors (48.4%) or outdoors (41.6%). Nearly two-thirds (63.0%) of the traumas occurred at age 10 years or later. Mean overjet (OJ) was larger (3.9 v 3.0 mm, P < .01), and lip incompetence more frequent (12.7% v 7.3%, P < .01) among the subjects with injured maxillary incisors than among those without. Logistic regression showed that the odds of maxillary incisor trauma were 2.8 times higher in subjects with OJ between 6.5 and 9.0 mm, and 3.7 times higher in subjects with OJ > or = 9.5 mm than in subjects with OJ < or = 3.5 mm. CONCLUSIONS: Multiple logistic regression showed that the risk of maxillary incisor trauma was about 2 times higher in boys than in girls, and that the risk increased by 13% for every millimeter of increase in OJ. Lip competence was not included in the model. No associations were found between occlusion and mandibular incisor trauma.     

Subtotal resection of clavicle for chronic, recurrent, multifocal osteomyelitis in children

Chronic, recurrent, multifocal osteomyelitis (CRMO) is an obscure disease of bone, occurring in children. It appears to be an inflammatory condition with no obvious microbiological cause. Current treatments of antibiotics and anti-inflammatory medication appear to have limited success. This case report looks at two separate cases of CRMO where partial resection of the affected bone—the clavicle—leads to complete resolution of symptoms and regrowth of the excised bone.     

Aspects of imported malaria at a district general hospital in non-endemic Kuwait,Arabian Gulf

There is no indigenous mosquito-borne transmission of malaria in Kuwait. However, in a five year period at a district general hospital, the number of laboratory-diagnosed cases of malaria increased annually from 25 to 84, a rise of 336%. Except for two induced infections, all were imported, mainly from the Indian subcontinent. Plasmodium vivax was responsible for 87.29% of the cases; P. falciparum (12.05%), a mixed infection of P. vivax and P. falciparum (0.33%) and a case of P. ovale (0.33%) were also identified. Rapid preparation of acetone-fixed, Giemsa-stained thick blood films, a heightened awareness of the infection, examination of multiple samples of blood from patients and the general resurgence of malaria in endemic areas were some of the factors responsible for the high number of cases diagnosed. Most patients were young males and presented with clinical malaria due to P. vivax between May and October each year, an apparent seasonal peak. However, many were already resident in the country for a variable period. Patients with P. falciparum though, presented clinically within two weeks of arrival in the country. Parasite densities were calculated to monitor the progress of treatment and identify quickly any possible chloroquine-resistant P. falciparum strains. A policy of active prophylaxis is suggested to stem the tide of imported malaria.Corresponding author.     

Liver cirrhosis induced by carbon tetrachloride and the effect of superoxide dismutase and xanthine oxidase inhibitor treatment.

Repeated administration of carbon tetrachloride (CCl4) induces liver cirrhosis, possibly because it involves the production of free radicals. In order to evaluate the effect of free radical scavengers such as superoxide dismutase (SOD) and allopurinol in the pathogenesis of liver cirrhosis, rats were subjected to repeated CCl4 administration with and without scavengers. Four groups of animals were studied: CCl4 plus SOD (group 1), CCl4 plus allopurinol (group 2), CCl4 alone (group 3) and olive oil (group 4, normal controls). Analysis of plasma and tissue concentrations of trace elements was performed and histopathological patterns were studied in all groups after 7 weeks of repeated intraperitoneal administration of the solutions. Plasma levels of zinc and selenium were significantly lower in all experimental groups, with reciprocal elevation of manganese and copper. Copper and manganese content in the liver tissue was significantly higher in all three experimental groups. The zinc content was elevated in groups receiving CCl4 alone (group 3) or with allopurinol (group 2). The liver selenium, however, was significantly lower in these two groups. The copper:zinc ratio for plasma was 0.78 in the control group, 1.6 in the CCl4 group, 1.3 in the allopurinol group and 1.5 in the SOD group. For liver tissue, the ratio was 0.07 for controls, 0.17 for CCl4, 0.11 for allopurinol and 0.28 for the SOD group. The changes in trace element content correlated with the severity of cellular damage observed microscopically in the liver. The higher the copper:zinc ratio, the more advanced and extensive was the microscopic evidence of liver injury after CCl4 challenge.     

Tyramine neurotoxicity and first-pass brain technetium-99m-diethylenetriamine penta-acetic acid

Tyramine induces coma in phenelzine-treated dogs with liver disease. The objective of the present investigation was to examine the influence of tyramine in these monoamine oxidase-inhibited dogs on the kinetics of Tc-99m-diethylenetriamine penta-acetic acid (Tc-99m-DTPA) during its first passage through the brain by nuclear imaging techniques. The study began with anesthetized mongrel dogs (n = 10) in a supine position over the camera detector. Data acquisition was started simultaneously after the rapid intracarotid injection of Tc-99m-DTPA (5 mCi) and 60 0.5-sec images of the brain were taken. Tyramine induced increased uptake with a concomitant impairment in the elimination of Tc-99m-DTPA from the brain of these phenelzine-treated animals with hepatic injury (n = 5) as compared to pretreated animals serving as a control group or phenelzine-treated animals without liver disease. This was accompanied by an appreciable reduction in hemispheric cerebral blood flow (50.5 +/- 19.3 vs. 110 +/- 16 ml/100 g/min), respectively. Increased cerebrovascular permeability of Tc-99m-DTPA and decreased cerebral blood flow occurred concomitantly with increased cerebrospinal fluid pressure and elevation in cerebrospinal fluid catecholamines of monoamine oxidase-inhibited animals with hepatic injury.     

A rapidly inactivating Ca2+-dependent K+ current in pheochromocytoma cells (PC12) of the rat

The membrane electrical properties of undifferentiated pheochromocytoma cells of the rat (PC12) were studied using both current-and voltage-clamp techniques with the use of low-resistance blunt-tipped micropipettes (patch electrodes). In the presence of tetrodotoxin (TTX, 2–3 M), a spike-like wave form with a prominent after-hyperpolarization (AHP) was recorded following brief (< 10 ms) depolarizing current pulses. The inorganic divalent cations, Cd²⁺ (0.5 mM), Mn²⁺ (4mM), and 0 mM Ca²⁺/4 mM Mg²⁺ solution prolonged the duration, attenuated the AHP, slowed the rate of repolarization, and slightly enhanced the amplitude of this wave form. A rapidly inactivating outward current was recorded in over 70% of the cells under voltage-clamp conditions. This transient current was elicited at about ±30 mV, and was blocked by tetraethylammonium (5 mM), inorganic divalent cations (Cd²⁺, 0.5 mM; Mn²⁺, 4 mM; Ba²⁺, 3 mM), and removal of Ca²⁺ (0 mM Ca²⁺/4 mM Mg²⁺) from the local perfusion medium. In addition, 4-aminopyridine (5 mM), which blocks the transient outward K⁺ current I_A in a variety of excitable cells, did not have any appreciable effect on this rapidly inactivating current. Moreover, it was possible to elicit the current at a holding potential of ±40 mV. The reversal potential of this current was ±90 mV, and shifted positively when extracellular K⁺ concentrations were elevated. It is concluded that PC12 cells have a rapidly inactivating Ca²⁺ -dependent K⁺ current. A possible explanation for the transient nature of this current may be the presence of an effective intracellular Ca²⁺ buffering (uptake or extrusion) system.     

Comparative histopathology of lesions produced by Actinomyces israelii, Actinomyces naeslundii, and Actinomyces viscosus in mice.

The histopathologic features of experimental actinomycotic lesions produced in mice by Actinomyces israelii, Actinomyces naeslundii, and Actinomyces viscosus were examined. In lesions caused by A israelii the outer edge of the bacterial granule exhibited an eosinophilic fringe with no evidence of penetration of polymorphonuclear leukocytes (PMNs) into the bacterial granule. Chronic lesions after 6 weeks contained lobulated advancing fronts as well as areas of resolution showing heavy penetration by phagocytic cells. The number of macrophages and plasma cells in these lesions increased with time. In contrast, lesions caused by A viscosus and A naeslundii showed cellular evidence of resolution during the early stages of the infection (3-6 weeks). The bacterial core was readily penetrated and fragmented by PMNs in early A viscosus lesions. In lesions caused by A naeslundii there was less penetration of the central core by PMNs, and the bacterial granule tended to retain its structural integrity. Elongated crystals of hyaloid material appeared in lesions caused by all species. These protein-rich bodies appeared to be associated with resolving areas of the lesions. The observed contrast in the histopathologic appearance of actinomycotic lesions caused by A israelii, A naeslundii, and A viscosus is suggestive of important differences in the immune response of the host to infections caused by these three species.     

An association between Gc (vitamin D-binding protein) alleles and susceptibility to rheumatic fever.

Rheumatic fever is associated with exaggerated activity of B cells with massive production of antibody to the Group A streptococcus. Gc (vitamin D-binding protein) is constitutively expressed on B-cell membranes in association with membrane immunoglobulin, and could be involved in cell activation. We therefore looked for associations between the three major Gc alleles and susceptibility to rheumatic fever in a homogeneous Arab population. Patients with tuberculosis or rheumatoid arthritis and control donors, were studied in parallel. Allele frequencies in the controls, rheumatoid and tuberculosis patients were identical to those found in a previous study of normal Arab donors. However, there was a striking association between Gc2 and rheumatic fever. This allele was twice as common in these patients as in controls (p = 0.0024), and was present in 56.4% of all rheumatic fever patients.     

The seasonal variation in allergic rhinitis and its correlation with outdoor allergens in Kuwait

BACKGROUND: Allergic rhinitis (AR) is the most common allergic problem in Kuwait. Most of the patients who have either AR or asthma are referred to the Al-Rashed Allergy Center. OBJECTIVE: To determine if there is a seasonal variation in AR in Kuwait and to correlate it with the daily pollen count. METHODS: Information about the new patients referred to the center over a 5-year study period (1996-2000) was extracted from the center's records. The daily pollen count in Kuwait city was obtained from the Air Biology Laboratory. RESULTS: There was a significant seasonal variation with a bimodal increase in the number of patients with AR referred to the center. The main peak in the number of patients occurred in September-October, and there was a smaller peak in April-May. The mean number +/- SD of new patients per month over the 5-year period varied from 87 +/- 32 for December to 367 +/- 104 for September. Similarly, the average daily pollen count varied from 3.7 +/- 1.0 pollens per mm3 in January to 124 +/- 92 in October. There was high correlation between the number of new AR patients and the average total pollen count (Pearson correlation, r=0.77, p<0.001), as well as with Chenopodiaceae and Amaranthaceae (weed) pollens (r=0.75, p<0.001), while there was no correlation between the number of new patients and either tree or grass pollens. CONCLUSION: Seasonal AR occurs during two periods in Kuwait, i.e. September-October and April-May, with September-October being the main season. The rise in AR during late summer in Kuwait is mainly associated with the pollination of Chenopodiaceae species.     

Neurological manifestations of human parvovirus B19 infection

Since its discovery, human parvovirus B19 has been linked with a broad spectrum of clinical syndromes. An aetiological role for the virus has been confirmed in erythema infectiosum, transient aplastic crisis, persistent infection manifesting as pure red cell aplasia in immunocompromised persons, non-immune hydrops fetalis and arthritis. Less commonly recognised, but receiving increasing attention recently, are the neurological manifestations, a variety of which have been described in patients with either clinically diagnosed or laboratory confirmed B19 infection. The purpose of this review is to summarise present knowledge of B19, its known and potential pathogenic mechanisms and its association with human diseases, particularly those with neurological manifestations. The outcome of the review supports an aetiological role of the virus in neurological disease. However, the pathogenesis remains unknown and elucidating this is a priority.