Peri-implant collagen fibers around human cone Morse connection implants under polarized light: a report of three cases

Most of the histologic studies found in the literature on the peri-implant soft tissues have been done in animals and usually have been confined to mandibular implants fitted with healing or standard abutments. Few studies have investigated human peri-implant soft tissues. Moreover, the structure and dimensions of the peri-implant soft tissues in immediately loaded implants have not been investigated in depth. Human histologic data are valuable to validate animal models. This histologic and histomorphometric study evaluated the peri-implant soft tissues around three immediately loaded implants in humans. The implants were retrieved using a trephine and treated to obtain thin, ground sections. The sulcular epithelium was composed of approximately four to five layers of parakeratinized epithelial cells and had a length of approximately 1.2 to 1.3 mm. The junctional epithelium was composed of approximately three to four layers of epithelial cells and had a length of approximately 1.0 to 1.5 mm. Connective tissue attachment had a width of between 400 and 800 μm. Peri-implant collagen fibers, in the form of bundles (1- to 5-μm thick), began at the crestal bone and were oriented perpendicular to the abutment surface until 200 μm from the surface, where they became parallel running in several directions. Collagen fibers appeared to form a three-dimensional network around the abutment. No acute or chronic inflammatory cell infiltrate was present. Collagen fibers oriented in a perpendicular manner and in direct contact with the abutment surface were not observed in any of the specimens. This differentiated network of fibers may have clinical relevance as a mechanical protection of the underlying bone. These human histologic data are extremely valuable to validate and confirm those obtained from studies performed on animal models. Moreover, immediate loading of the implants did not compromise soft tissue integration.     

Histologic and histomorphometric evaluation of an implant retrieved 8 years after insertion in a sinus augmented with anorganic bovine bone and anorganic bovine matrix associated with a cell-binding peptide: a case report

Few histologic and histomorphometric reports are present in the literature regarding the peri-implant bone response around implants inserted in sinuses grafted with different biomaterials. Anorganic bovine bone (ABB) and anorganic bovine matrix with the addition of an active cell-binding peptide (PepGen P-15) are xenogenic materials that have been reported to present biocompatibility and osteoconductivity. A monolateral sinus augmentation procedure with ABB (50%) and PepGen P-15 (50%) was performed in a 54-year-old man. Two titanium implants with a sandblasted and acid-etched surface were inserted after 6 months. After an additional 6 months, a fixed prosthetic restoration was fabricated. One implant fractured in the coronal portion after an 8-year loading period and was removed using a 5-mm trephine bur. Few particles of both grafting materials were present in the peri-implant bone. No graft material particles were found in contact with the implant surface, and bone was always interposed between the graft materials and surface. No inflammatory cell infiltrate, multinucleated giant cells, or foreign body reaction cells were found. The tissues around the implant were composed of 51.4% ± 4.8% bone, 6.2% ± 0.7% ABB particles, 2.4% ± 0.5% PepGen P-15, and 40.0% ± 7.1% marrow spaces. The bone-implant contact percentage was 78.4% ± 4.1%. A sinus augmentation procedure using ABB and PepGen P-15 produced bone formation with subsequent implant osseointegration, which was still present after 8 years of implant loading.     

CYP2B6, ABCB1 and OPRM1 profile in a stillborn affected by chronic methadone intoxication

Forensic Toxicology -     

Matrix Metalloproteinase‐2 Activity is Associated with Divergent Regulation of Calponin‐1 in Conductance and Resistance Arteries in Hypertension‐induced Early Vascular Dysfunction and Remodelling

Matrix metalloproteinase (MMP)‐2 participates in hypertension‐induced maladaptive vascular remodelling by degrading extra‐ and intracellular proteins. The consequent extracellular matrix rearrangement and phenotype switch of vascular smooth muscle cells (VSMCs) lead to increased cellular migration and proliferation. As calponin‐1 degradation by MMP‐2 may lead to VSMC proliferation during hypertension, the hypothesis of this study is that increased MMP‐2 activity contributes to early hypertension‐induced maladaptive remodelling in conductance and resistance arteries via regulation of calponin‐1. The main objective was to analyse whether MMP‐2 exerts similar effects on the structure and function of the resistance and conductance arteries during early hypertension. Two‐kidney, one‐clip (2K‐1C) hypertensive male rats and corresponding controls were treated with doxycycline (30 mg/kg/day) or water until reaching one week of hypertension. Systolic blood pressure was increased in 2K‐1C rats, and doxycycline did not reduce it. Aortas and mesenteric arteries were analysed. MMP‐2 activity and expression were increased in both arteries, and doxycycline reduced it. Significant hypertrophic remodelling and VSMC proliferation were observed in aortas but not in mesenteric arteries of 2K‐1C rats. The contractility of mesenteric arteries to phenylephrine was increased in 2K‐1C rats, and doxycycline prevented this alteration. The potency of phenylephrine to contract aortas of 2K‐1C rats was increased, and doxycycline decreased it. Whereas calponin‐1 expression was increased in 2K‐1C mesenteric arteries, calponin‐1 was reduced in aortas. Doxycycline treatment reverted changes in calponin‐1 expression. MMP‐2 contributes to hypertrophic remodelling in aortas by decreasing calponin‐1 levels, which may result in VSMC proliferation. On the other hand, MMP‐2‐dependent increased calponin‐1 in mesenteric arteries may contribute to vascular hypercontractility in 2K‐1C rats. Divergent regulation of calponin‐1 by MMP‐2 may be an important mechanism that leads to maladaptive vascular effects in hypertension.     

Effects of resistance training of moderate intensity on heart rate variability,body composition,and muscle strength in healthy elderly women

Purpose

The practice of resistance training is recommended as non-pharmacological strategy during aging. In this study, we propose training composed of exercises, leg 180° press, seated row, leg curl, bench press, abduction machine, push down, adduction machine, and curl biceps. Accordingly, this study aimed to determine the effects of dynamic resistance training on autonomic response, muscle strength, and body composition of elderly women without comorbidities.

Methods

Twenty-six healthy older women (65 ± 3 years) were randomly divided into two groups. The Control Group (CG) consisted of 13 subjects not engaged in any physical exercise, while the Training Group (GT) (n = 13) performed 8 strength training exercises with 3 sets of 8 maximum repetitions. Heart rate variability, body composition, and muscle strength were assessed before and after the 12 weeks in both groups.

Results

No significant difference was found in body composition, muscle strength, and heart rate variability between CG and TG before (baseline) 12 weeks of training. Significant differences between pre- and post-training moments were found only in training group. In this sense, results demonstrated improvement (p < 0.05) in body fat mass (23.0 ± 1.2 vs. 20.0 ± 1.1 kg), fat-free mass (38.0 ± 1.5 vs. 42.0 ± 1.4 kg), strength of upper (17.8 ± 1.0 vs. 22.2 ± 1.1 kgf) and lower limbs (27.1 ± 2.4 vs. 34.1 ± 2.5 kgf), and in time and frequency domain measures of heart rate variability, highlighting the indices LF/HF (1.2 ± 0.4 vs. 0.7 ± 0.1).

Conclusions

The dynamic resistance training protocol presented in this study may be regarded as an effective approach to prevent cardiovascular morbidity and mortality in elderly women.

     

Histocompatibility class I and II antigens in extensive kindred with Sneddon's syndrome and related hypercoagulation disorders

We have studied the relationship between the histocompatibility class I and II antigens and Sneddon's syndrome (SS) in a Spanish patient with SS and her relatives (13 available members of an extensive 3-generation pedigree with diverse autoimmune hypercoagulation abnormalities). The patient and her father were diagnosed with a primary antiphospholipid antibody syndrome and were HLA-A30-B13-Bw6. In addition, a HLA-Bw6-DQ1 association was present in all the members of this kindred. These data suggest that the combination of the histocompatibility class I and II antigens in this family may be a marker for predisposition to SS.