Peri-Implant Soft Tissue Augmentation

The peri-implant soft tissue (PIS) augmentation procedure has become an integral part of implant-prosthetic rehabilitation. Minimal width of keratinized mucosa (KM) of 2 mm is deemed necessary to facilitate oral hygiene maintenance around the implant and provide hard and soft peri-implant tissue stability. PIS thickness of at least 2 mm is recommended to achieve the esthetic appearance and prevent recessions around implant prosthetic rehabilitation. The autogenous soft tissue grafts can be divided into two groups based on their histological composition—free gingival graft (FGG) and connective tissue graft (CTG). FGG graft is used mainly to increase the width of keratinized mucosa while CTG augment the thickness of PIS. Both grafts are harvested from the same anatomical region—the palate. Alternatively, they can be harvested from the maxillary tuberosity. Soft tissue grafts can be also harvested as pedicle grafts, in case when the soft tissue graft remains attached to the donor site by one side preserving the blood supply from the donor region. Clinically this will result in less shrinkage of the graft postoperatively, improving the outcome of the augmentation procedure. To bypass the drawback connected with FGG or CTG harvesting, substitutional soft tissue grafts have been developed.

Split Lateral Forehead Flap for Reconstruction of Upper and Lower Eyelids

Background: Eyelids reconstruction after tumor resection has be one of the most challenging procedures in reconstructive plastic surgery. Small defects may be closed by primary suture or covered by small local flaps or skin graft. But in large eyelids defects, we need to find a bigger source of color and texture matching tissue that will ensure functional and aesthetical outcomes. Many techniques have been described, but in this case, the author suggest a split lateral forehead flap designed to cover upper and lower eyelids. Patient and Operation Techniques: A Male 51 years-old-patient, presented himself in our clinic with a basal cell carcinoma involving the right upper and lower eyelids. The tumor had a history of 7 years, without any pain or vision disorders involved. Tumor was widely excised, leaving a full thickness on upper and lower eyelids. The inner lining palpebral was replaced by composite auricular graft following by lateral cantophexy. A lateral forehead flap raised with a right temporal pedicle, and the distal part of flap was split in half, and inset into the upper and lower eyelids defect. The donor region was closed with an STSG from Femur Dextra. After 14 days the flap was divided, the functional result was excellent. Discussion: At first, surgeons were worried of raising forehead flaps beyond the midline, fearing that by splitting the distal flap would cause its compropmise. However, rich anastomostic plexus exists between the major forehead angiosomes lined by the smaller calibre “choke” vessels. Conclusions: Periorbital Basal cell carcinoma resection may leave great defect to the underlying tissue. The need to provide adequate support to this structure requires complex techniques with minimum two flaps. In our case, we performed a split lateral forehead flap with a good functional and cosmetic outcome.

DNA barcoding-based assessment of the invasive and native non-crustose Codium species in the central Cantabrian Sea, southern Bay of Biscay

In this work, we identified non-crustose invasive (Codium fragile subsp. fragile) and native Codium spp. (Codium tomentosum and Codium vermilara) in the central Cantabrian Sea using DNA barcoding (tufA and rbcL genes). We designed a new FCOtufA genetic marker for identifying Codium spp. in fresh and herbarium material. The tufA and rbcL sequences revealed three different single haplotypes for each of the species and a lack of intraspecific genetic diversity. The FCOtufA genetic marker revealed one new haplotype of C. fragile within the native region (South Korea), suggesting the possibility of higher genetic diversity in the donor region of this invasive species.

Arterial Steal to the Penumbra Area in Patients with Acute MCA Occlusion: A Quantitative Angiographic Analysis

Purpose: In acute middle cerebral artery (MCA) occlusion, collateral vessels provide retrograde supply to the occluded territory. We hypothesized that such collateral flow reduces perfusion of the non-occluded donor region (steal effect).Materials and Methods: Patients with an MCA occlusion with opacification of both ipsi- and contralateral anterior cerebral arteries (ACA) on angiography prior to endovascular treatment were selected. Arteriovenous transit time (AVTT) for both ACA territories was compared for different grades of collateral supply to the MCA territory. In addition, the influence of diabetes and hypertension was analyzed. After successful revascularization, AVTT was re-assessed to determine reversibility.Results: Forty-one patients were analyzed. An AVTT of 8.6 seconds (standard deviation [SD] 2.4 seconds) was seen in the ACA territory of the affected hemisphere in comparison to 6.6 seconds (SD 2.1 seconds) for the contralateral side (P<0.001). A more prolonged (but not significant) AVTT was seen in cases with a higher collateral grade. No difference in AVTT was seen in patients with diabetes or hypertension. After successful MCA revascularization, AVTT delay was 7.4 seconds (SD 2.1 seconds).Conclusion: A cerebral steal effect occurs in patients with an acute MCA occlusion, probably related to augmented flow to the penumbra area.

The Routine and Specialised Staining for the Histologic Evaluation of Autogenous Mandibular Bone Grafts An experimental study

Oral rehabilitation by dental implants is a routine treatment in the common dental practice, and volume reconstruction in cases of advanced alveolar ridge atrophy using bone autografts has become a frequently used therapeutic procedure. The study presents a histological evaluation of autogenous mandibular bone grafts integration in surgically created maxillary bone defects. Seven domestic adult dogs, Canis Familiaris were used in the study. Work methodology was established through maxillary and mandibular morphometry, the donor region being the posterior mandibular body, and the recipient region being the lateral body of the maxilla. In the experimental study, we simulated two bilateral maxillary bone defects, which were augmented with mandibular corticocancellous bone grafts. Biological samples containing the target areas were collected 90-100 days after grafting and the subsequent preparation method of the samples for histological analysis was the standard one.The histological results showed the successful integration and the beneficial effect of corticocancellous autogenous mandibular bone grafts applied in maxillary sites.

Frequent nonallelic gene conversion on the human lineage and its effect on the divergence of gene duplicates

Gene conversion is the copying of a genetic sequence from a “donor” region to an “acceptor.” In nonallelic gene conversion (NAGC), the donor and the acceptor are at distinct genetic loci. Despite the role NAGC plays in various genetic diseases and the concerted evolution of gene families, the parameters that govern NAGC are not well characterized. Here, we survey duplicate gene families and identify converted tracts in 46% of them. These conversions reflect a large GC bias of NAGC. We develop a sequence evolution model that leverages substantially more information in duplicate sequences than used by previous methods and use it to estimate the parameters that govern NAGC in humans: a mean converted tract length of 250 bp and a probability of 2.5×10−7 per generation for a nucleotide to be converted (an order of magnitude higher than the point mutation rate). Despite this high baseline rate, we show that NAGC slows down as duplicate sequences diverge—until an eventual “escape” of the sequences from its influence. As a result, NAGC has a small average effect on the sequence divergence of duplicates. This work improves our understanding of the NAGC mechanism and the role that it plays in the evolution of gene duplicates.

Moscow considers stripping Tatarstan of special status

Significance The Kremlin is saying nothing, but seems unlikely to approve an extension and has not initiated the legislation needed for this. Ending the treaty will annul Tatarstan's claim to unique political and economic sovereignty, although its real autonomy has been greatly eroded over the last decade. Impacts Abandoning the Tatarstan treaty may signal a new Kremlin impetus for greater centralisation and a unitary state. Tatarstan will retain its position as a wealthy donor region. Regional leaders will resent the special treatment given to Crimea and Chechnya at the other end of the economic spectrum.

Frequent non-allelic gene conversion on the human lineage and its effect on the divergence of gene duplicates

Gene conversion is the copying of genetic sequence from a “donor” region to an “acceptor”. In non-allelic gene conversion (NAGC), the donor and the acceptor are at distinct genetic loci. Despite the role NAGC plays in various genetic diseases and the concerted evolution of gene families, the parameters that govern NAGC are not well-characterized. Here, we survey duplicate gene families and identify converted tracts in 46% of them. These conversions reflect a large GC-bias of NAGC. We develop a sequence evolution model that leverages substantially more information in duplicate sequences than used by previous methods and use it to estimate the parameters that govern NAGC in humans: a mean converted tract length of 250bp and a probability of 2.5×10−7per generation for a nucleotide to be converted (an order of magnitude higher than the point mutation rate). Despite this high baseline rate, we show that NAGC slows down as duplicate sequences diverge—until an eventual “escape” of the sequences from its influence. As a result, NAGC has a small average effect on the sequence divergence of duplicates. This work improves our understanding of the NAGC mechanism and the role that it plays in the evolution of gene duplicates.