Cells of the monocyte-macrophage lineage and pathogenesis of HIV-1 infection

It is thought that monocyte-macrophages and probably dendritic cells play a central role in HIV-1 primary infection, as well as in its evolution, given that they are among the first cells infected and later function as important reservoirs for the virus. These cells may participate in the selection of certain viral strains instead of others. Levels of CCR5 coreceptor expression on the surface of monocytes and macrophages determine their susceptibility to infection by HIV-1 strains using this coreceptor and may explain, in part, the differences in the infectivity of these cells through the maturation process. However, selection for certain strains is not only determined by the level of coreceptor expression, but by the biochemical properties of the different coreceptors and their relationship with other surface molecules and the chemokine and cytokine networks, which also influence the selective viral infection and replication in these cells. Any current or newly designed therapies need to be evaluated, including careful analysis of the levels of HIV-1 infection of the cells of the monocyte-macrophage lineage, because these cells are both significant viral reservoirs and a center of virus production at all stages of the disease.     

Effects of topical application of free and liposome-encapsulated lactoferrin and lactoperoxidase on oral microbiota and dental caries in rats

Four groups of rats were inoculated with Streptococcus sobrinus ATCC 33478 and fed a cariogenic diet for 42 days. Topical treatment with either distilled water, sodium fluoride (0.2%), a solution containing lactoferrin and lactoperoxidase, or a solution containing liposome-encapsulated lactoferrin and liposome-encapsulated lactoperoxidase was applied at intervals for 35 days. Caries incidence in groups treated with liposome-encapsulated lactoferrin and lactoperoxidase was significantly lower than in control groups. The number of viable Strep. sobrinus and the proportion of Strep. sobrinus in the total counts were significantly higher in liposome-treated groups. Free lactoferrin and lactoperoxidase did not cause a significant reduction in caries incidence.     

Association of HLA-DR11 with the anaphylactoid reaction caused by nonsteroidal anti-inflammatory drugs

BACKGROUND: Several HLA alleles have been associated with asthma induced by nonsteroidal anti-inflammatory drugs (NSAIDs). The existence of HLA markers linked to other NSAID-induced reactions, such as cutaneous and anaphylactoid reactions, has not been established. OBJECTIVE: The purpose of our work was to study the HLA-DRB1 and HLA-DQB1 alleles in patients with cutaneous and anaphylactoid reactions caused by NSAIDs. METHODS: We have analyzed 114 HLA DRB1 and 26 HLA-DQB1 alleles in 21 patients with anaphylactoid reactions caused by NSAIDs, 47 patients who had exclusively cutaneous reactions during single-blind, placebo-controlled oral challenges with NSAIDs, and 167 tolerant control subjects (29 of whom had also had an IgE-mediated anaphylaxis to different agents). HLA-DRB1 and HLA-DQB1 alleles were typed by the polymerase chain reaction sequence-specific primers method with genomic DNA. RESULTS: The frequency of HLA-DR11 alleles was 58.8% in the anaphylactoid reaction group, compared with 15.9% in the NSAID-tolerant healthy control subjects (OR, 7:3; 95% confidence interval, 2.8-19.0; P <.02) and 6.3% in the group of the patients with a tolerance for NSAIDs and with IgE-mediated anaphylaxis (OR, 18.75; 95% confidence interval, 4.3-81.1; P <.004). No differences were observed among HLA-DR11 alleles analyzed. There were no significant HLA-DQB1 associations with NSAID-induced anaphylactoid reactions. Patients with cutaneous reactions had HLA frequencies that did not differ significantly from the tolerant control subjects. CONCLUSION: The HLA-DRB1*11 alleles showed a positive association with NSAID-induced anaphylactoid reactions.     

Lethal neonatal Hutchinson-Gilford progeria syndrome

We report on a 35-week gestation female fetus with Hutchinson-Gilford progeria (HGP). This patient, who is the first reported with neonatal HGP in the English literature but is the fourth, counting three previous French cases, supports the existence of a more severe prenatal form of progeria. She died 7 hours after birth and presented with intrauterine growth retardation, premature aging, absence of subcutaneous fat, brachydactyly, absent nipples, hypoplastic external genitalia, and abnormal ear lobes. The child's combination of clinical and skeletal manifestations differentiates this form of HGP from other progeroid syndromes with neonatal presentation. We also report previously undescribed autopsy findings including premature loss of hair follicles, premature regression of the renal nephrogenic layer, and premature closure of the growth plates in the distal phalanges that may be related to the aging processes in this condition. We could not find any histological data to support acro-osteolysis, which is the radiographic sign of brachydactyly. The terminal phalanges in HGP seem to be underdeveloped rather than osteolytic.     

Meiotic abnormalities and spermatogenic parameters in severe oligoasthenozoospermia

The incidence of meiotic abnormalities and their relationship with different spermatogenic parameters was assessed in 103 male patients with presumably idiopathic severe oligoasthenozoospermia (motile sperm concentration < or = 1.5 x 10(6)/ml). Meiosis on testicular biopsies was independently evaluated by two observers. Meiotic patterns included normal meiosis and two meiotic abnormalities, i.e. severe arrest and synaptic anomalies. A normal pattern was found in 64 (62.1%), severe arrest in 21 (20.4%) and synaptic anomalies in 18 (17.5%). The overall rate of meiotic abnormalities was 37.9%. Most (66.7%) meiotic abnormalities occurred in patients with a sperm concentration < or = 1 x 10(6)/ml. In this group, total meiotic abnormalities were found in 57.8% of the patients; of these, 26.7% had synaptic anomalies. When the sperm concentration was < or = 0.5 x 10(6)/ml, synaptic anomalies were detected in 40% of the patients. In patients with increased follicle stimulating hormone (FSH) concentrations, total meiotic abnormalities occurred in 54.8% (synaptic anomalies in 22.6%). There were statistically significant differences among the three meiotic patterns in relation to sperm concentration (P < 0.001) and serum FSH concentration (P < 0.05). In the multivariate analysis, sperm concentration < or = 1 x 10(6)/ml and/or FSH concentration > 10 IU/l were the only predictors of meiotic abnormalities.     

Periodontal regeneration of intrabony defects using resorbable membranes: determinants of the healing response. An observational clinical study

The safety and bone-regenerative capacity of a resorbable membrane (Resolut) was evaluated by a nonrandomized prospective clinical study of patients with periodontal defects. Prior to surgical management all patients underwent scaling and root planing and were instructed on oral hygiene. The study included 18 patients (31 periodontal defects) who received surgical treatment by guided tissue regeneration (GTR) using resorbable membranes. The results were evaluated 12 months after surgery in terms of Plaque Index, bleeding index, probing depth, gingival recession, clinical attachment level, and dental mobility. The results obtained show that the use of resorbable membranes in GTR causes few complications. The mean gain in clinical attachment level (4.06 +/- 1.91 mm), with an attachment level gain of more than 3 mm in 81.2% of the defects, suggests the presence of "new attachment." This difference was clinically and statistically significant (t = 11.03, P = 0). The multivariate regression study showed that 60% of the observed variability (F = 11.48, P < 0.001) in clinical attachment level gain was accounted for by the variable's initial probing depth, the Plaque Index of the tooth subjected to GTR, and the infrabony component of the defect.     

Masseteric silent period in healthy young adults

The length of the silent period (SP) has been subject of extensive researches and its use has been established for the diagnosis of dysfunctional individuals. Because of its great variability we should be cautious about its assessment. This study is aimed to find the normal values taken in symptomless subjects using a commercial/medical recording system, designed for clinical use. Thirty-six readings of the SP have been taken causing a chin tap. The assessment of the motor dysfunction and the subsequent depressed activity gave the result of 32.37 ms (SD = 19.47, ranged from 15 to 110). This is slightly more extended than the results described by the majority of the Authors.     

A study on impact and tensile strength of acrylic resin filled with short ultra-high molecular weight polyethylene fibers

In dentistry, acrylates have been used for preparing denture bases for 50 years. Although polymethylmethacrylates (PMMA) are known to be an ideal base material, they possess some undesirable mechanical properties, especially their impact strength and tensile strength, which appear to be unsatisfactory for some applications. Additives and fibers have therefore been used to enhance and improve these properties over the last two decades. The present article describes the mechanical properties, impact and tensile strength of PMMA reinforced with chopped ultra-high molecular weight polyethylene fiber (6 mm long). It was found that, although the processing involved for high loading of fibers into the PMMA was difficult, the resulting improvement of impact strength was substantial.