Islanded facial artery osteomyomucosal/osseous flap in head and neck reconstruction

A local pedicled vascularized bone flap can prevent the morbidity and cost of free bone flap surgery in small segmental bone defects or long cartilaginous defects of the head and neck. Such flaps can also be useful in patients who are high risk for surgery. The periosteal vascularity of the mandible can be used to design islanded facial artery-based bone flaps, which can be utilized to that extent. Two patients with a small segmental mandibulectomy defect and one patient with a long cricotracheal resection defect underwent reconstruction using three different designs of islanded facial artery osteomyomucosal/osseous flap (iFOMM). The patients had a minimum follow-up period of 18 months. All flaps were successful, with satisfactory healing and without any functional deficit or disease at last follow-up.     

Head and Neck Histoplasmosis—A Nightmare for Clinicians and Pathologists! Experience at a Tertiary Referral Cancer Centre

Histoplasmosis is a rarely reported deep mycotic infection in the Indian context. Oral or oropharyngeal manifestation can occur as an isolated symptom or as part of a disseminated process associated with immunosuppression especially with HIV and diabetes. Five cases of head and neck histoplasmosis accrued over 6 years in a tertiary referral cancer institute were reviewed. All these patients presented clinically as cancer. In three patients, the marked pseudoepitheliomatous hyperplasia led to a mistaken biopsy diagnosis of malignancy following which definitive surgical treatment was performed. The subsequent excision revealed typical features of histoplasmosis. Isolated oral presentation of histoplasmosis can mimic malignancy both clinically as well as pathologically, leading to potentially disastrous consequences. A high index of suspicion in those with overt or hidden immunosuppression and a deep wedge biopsy to demonstrate the organisms in the subepithelial tissue is recommended. This work has been presented in the “Slide seminar on Infections and Infestations” in the IAP-ID pre conference CME in APCON 2006.     

Deltoid flap combined with fascia lata autograft for rotator cuff defects: a histologic study

The purpose of this study was to compare the histological characteristics of an autogenous fascia lata graft alone and a fascia lata graft combined with a deltoid flap in the reconstruction of rotator cuff tears. Ten New Zealand white rabbits were divided into two groups. Infraspinatus tendon defects (1 × 1 cm) were created in each animal. Reconstruction consisted of either a fascia lata graft alone or a fascia lata graft combined with a distally based deltoid flap. At 3 months, tissue harvest and histological analysis was performed. Compared to the fascia lata graft alone, there was significantly increased remodeling activity and neovascularization in the group that included a deltoid flap. Also, there was pronounced interdigitation at the graft/flap interface in the latter group. A mutually beneficial relationship may exist when an autogenous fascial graft is combined with a functional deltoid flap for reconstructing large rotator cuff defects.     

Nonspecific antiviral immunity by formalin-fixed Coxiella burnetii is enhanced in the absence of nitric oxide

Mice treated with a single injection of formalin-fixed Coxiella burnetii showed a significant increase in resistance to vaccinia virus (VV) infection compared to untreated mice. C. burnetii stimulated dramatically high levels of nitric oxide (NO) in the serum of treated mice, suggesting that NO might play a role in resistance to virus infection. To test this hypothesis, the effect of C. burnetii treatment on VV replication was examined in NOS2-/- and wild-type mice. C. burnetii treatment inhibited VV replication in both the knockout and wild-type mice but the effect was significantly greater in the NOS2-/- mice. Experiments in IFNgamma receptor knockout mice indicated that the nonspecific antiviral immunity induced by C. burnetii was dependent on IFNgamma and not NO. In the absence of NO, indoleamine 2,3-dioxygenase (IDO) was increased in C. burnetii-treated mice and this may contribute to the accelerated virus clearance in NOS2-/- mice.     

Spurious automated red cell parameters due to cold agglutinins--a report of two cases

Although automation in hematology has resulted in improved accuracy of results, there are certain clinical conditions in which even the technologically advanced cell counters give out spurious results. It is therefore important that operators of these instruments are aware of these factitious results and the clues in the automated data that can be of help in identifying them. Two cases with spurious automated red cell parameters due to cold agglutinins are reported here.     

Use of the gel-based DiaMed-ID microtyping system for crossmatching enhances sensitivity

A host of newer techniques have been introduced over the past decade in blood bank serological testing. One such technology which has been in vogue in the west since early 1990s is the gel test. The procedures used are standardized and they provide clear and stable reactions that improve result interpretation. The principle involves the differential passage of red cell agglutinates and free red blood cells through a dextran acrylamide gel. The results are stable and may be read even after many hours. The test is easy to perform, sensitive and reproducible. We report our experience in compatibility testing with use of the DiaMed micro typing system which is based on the gel technology. Over a one year period since this technology was introduced in our blood bank, we noticed a startling 65 fold rise (p<0.0001) in the reported number of incompatible units in one year which rose from a paltry 4 (0.02%) to 260 (1.6%). We found the DiaMed system easy to use and as our findings suggest it proved to be more sensitive than the conventional tube agglutination technique.     

Modelling HA protein-mediated interaction between an influenza virus and a healthy cell: pre-fusion membrane deformation.

We present a mathematical model for pre-fusion interaction between an influenza virus and a healthy cell. Our model describes the role played by hemagglutinin (HA) protein clusters in bringing the viral membrane into close contact with the host cell membrane as a first step of the fusion process between the two membranes. The viral membrane is modelled as a lipid bilayer with bending rigidity. Using the calculus of variations, we compute the deformation of the viral membrane under the influence of HA protein clusters. Our numerical results support the hypothesis of dimple formation in the fusion site proposed in the literature. The asymmetric nature of the protein molecules due to various reasons such as tilting is the primary cause for the dimple formation. We discuss the effects of spontaneous curvature, the protein cluster radius, fusion-site size and the bending moment exerted by the protein cluster. We also examine the effects of membrane tension and the presence of a host cell on the dimple shape. Our results support previous experimental observations.