Surveilling the Potential for Precision Medicine-driven PD-1/PD-L1-targeted Therapy in HNSCC

Immunotherapy is becoming an accepted treatment modality for many patients with cancer and is now approved for use in platinum-refractory recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). Despite these successes, a minority of patients with HNSCC receiving immunotherapy respond to treatment, and few undergo a complete response. Thus, there is a critical need to identify mechanisms regulating immune checkpoints in HNSCC such that one can predict who will benefit, and so novel combination strategies can be developed for non-responders. Here, we review the immunotherapy and molecular genetics literature to describe what is known about immune checkpoints in common genetic subsets of HNSCC. We highlight several highly recurrent genetic lesions that may serve as biomarkers or targets for combination immunotherapy in HNSCC.

Core–shell alginate@silica microparticles encapsulating probiotics

Lactobacillus rhamnosus GG (LGG) was encapsulated in core–shell alginate–silica microcapsules by coating the electrosprayed ionogel with a silica shell via hydrolysis/condensation of alkoxysilane precursors.

Dielectric and mechanical relaxation in isooctylcyanobiphenyl (8*OCB)

The dynamics of isooctylcyanobiphenyl (8*OCB) was characterized using dielectric and mechanical spectroscopies. This isomer of the liquid crystalline octylcyanobiphenyl (8OCB) vitrifies during cooling or on application of pressure, exhibiting the typical features of glass-forming liquids: non-Debye relaxation function, non-Arrhenius temperature dependence of the relaxation times, τ(α), a dynamic crossover at T ∼ 1.6T(g). This crossover is evidenced by changes in the behavior of both the peak shape and the temperature dependence of τ(α). The primary relaxation time at the crossover, 2 ns at ambient pressure, is the smallest value reported to date for any molecular liquid or polymer. Interestingly, at all temperatures below this crossover, τ(α) and the dc conductivity remain coupled (i.e., conform to the Debye-Stokes-Einstein relation). Two secondary relaxations are observed in the glassy state, one of which is identified as the Johari-Goldstein process. Unlike the case for 8OCB, no liquid crystalline phase could be attained for 8*OCB, demonstrating that relatively small differences in chemical structure can effect substantial changes in the intermolecular potential.

Changes of relaxation dynamics of a hydrogen-bonded glass former after removal of the hydrogen bonds

Dielectric relaxation spectra of two closely related glass formers, dipropylene glycol [H-(C3H6O)2-OH] and dipropylene glycol dimethyl ether [CH3-O-(C3H6O)2-CH3], were measured at ambient and elevated pressures in the supercooled and the glassy states are presented. Hydrogen bonds formed in dipropylene glycol are removed when its ends are replaced by two methyl groups to become dipropylene glycol dimethyl ether. In the process, the primary relaxation, the excess wing, and the resolved secondary relaxation of dipropylene glycol are all modified when the structure is transformed to become dipropylene glycol dimethyl ether. The modifications include the pressure and temperature dependences of these relaxation processes and their interrelations. Thus, by comparing the dielectric spectra of these two closely related glass formers at ambient and elevated pressures, the differences in the relaxation dynamics and properties in the presence and absence of hydrogen bonding are identified.

Effect of probiotics and triple eradication therapy on the cyclooxygenase (COX)-2 expression, apoptosis, and functional gastric mucosal impairment in Helicobacter pylori-infected Mongolian gerbils

BACKGROUND

Helicobacter pylori infection in Mongolian gerbils is an established experimental model of gastric carcinogenesis that mimics H. pylori-positive patients developing gastric ulcer and gastric cancer, but the effect of probiotic therapy on functional aspects of this infection remains unknown.

METHODS

We compared the effects of intragastric inoculation of gerbils with H. pylori strain (cagA+ vacA+, 5 x 10(6) colony forming units/ml) with or without triple therapy including omeprazole, amoxicillin, and tinidazol or probiotic bacteria Lacidofil. Histology of glandular mucosa, the viable H. pylori, and density of H. pylori colonization were evaluated. The gastric blood flow was measured by H2-gas clearance method; the plasma gastrin and gastric luminal somatostatin were determined by RIA and expression of cyclooxygenase (COX)-2 and apoptotic Bax and Bcl-2 proteins were evaluated by Western blot.

RESULTS

The gastric H. pylori infection was detected in all animals by histology and H. pylori culture. Basal gastric acid was significantly reduced in H. pylori-infected animals but not in those with triple therapy or Lacidofil. Early lesions were seen already 4 weeks upon H. pylori inoculation and consisted of chronic gastritis and glandular atypia associated with typical regenerative hyperplasia and increased mitotic activity and formation of apoptotic bodies. The H. pylori infection was accompanied by the fall in gastric blood flow, the marked increase in plasma gastrin, the significant fall in gastric somatostatin levels and Bcl-2 protein expression, and the rise in expression of COX-2 and Bax proteins. These mucosal changes were counteracted by the triple therapy and Lacidofil.

CONCLUSIONS

H. pylori infection in gerbils, associated with regenerative hyperplasia of glandular structure, results in the suppression of gastric secretion, overexpression of COX-2, and enhancement in apoptosis and impairment of both, gastric blood flow and gastrin-somatostatin link that were reversed by anti-H. pylori triple therapy and attenuated by probiotics.

Pars plana vitrectomy foreign body extraction assisted with a 24-gauge needle tunnel

A 54-year-old man presented with corneal laceration, traumatized iris, small vitreous hemorrhage, lens opacity, and a 13-mm intraocular foreign body embedded in the retina. Pars plana vitrectomy and argon laser photocoagulation were performed. Using intraocular forceps, the object was forced into a 24-gauge needle that was inserted through the sclerotomy. The foreign body and the needle were removed from the eye. Phacoemulsification with foldable intraocular lens implantation in the ciliary sulcus was performed. Seven days after the surgery, the patient's visual acuity was 20/20 with spectacle correction of -3.5 diopters. The use of a needle tunnel during pars plana vitrectomy should be considered in similar cases of large, irregular intraocular foreign bodies to avoid severe and irreversible damage to the adjoining tissues.

Temperature and pressure dependence of the dynamics in a poly(methyl acrylate) side-chain liquid-crystalline polymer

The molecular dynamics of a side-chain polymer liquid crystal with a poly(methyl acrylate) backbone and a (p-alkoxy-phenyl)-benzoate mesogenic group have been studied in the unaligned state as a function of temperature and pressure using dielectric spectroscopy. Polarizing optical microscopy, differential scanning calorimetry, and pressure-volume-temperature (PVT) measurements revealed three transition temperatures separating four phases (glass, smectic, nematic, and isotropic). Different dynamic processes have been identified reflecting librational modes (gamma process), local relaxation of the mesogenic group (beta process), the segmental mode (alpha process) associated with the dynamic glass transition, and a slower process (delta process) reflecting the side-chain dynamics within the liquid crystal order. Pressure exerts a stronger influence on the alpha as compared to the delta process. Starting from the nematic phase, pressure was found to induce the nematic-to-smectic transformation. The associated dynamic changes were in excellent agreement with the PVT results implying that the dynamics are directly coupled to the thermodynamic state. Pressure was found to enhance the stability of the smectic order within the P-T phase diagram.

[Applying deep lamellar keratoplasty in corneal disorders without endothelial abnormalities]

PURPOSE

To present own experiences in the surgery of deep lamellar keratoplasty.

MATERIALS AND METHODS

25 eye of 25 patients suffering from various corneal pathologies with preserved endothelium: 22 with keratoconus eyes, 2 with post-inflammatory scar and one eye with leucoma in Stevens-Johnson syndrome. Mean follow-up was 25.5 months (from 6 to 32). Main outcome measures were Non-Corrected and Best Corrected Visual Acuity (NCVA, BCVA), astigmatism, refractive error, IOP and corneal transparency. The surgery was performed in general anesthesia. In majority of cases the recipient stroma was trephined to a depth of 70% with 7.5 mm diameter vacuum trephine. In cases of intraoperative perforation of Descemet membrane with shallow anterior chamber we converted the procedure into penetrating keratoplasty. The donor lenticule was trephined in the artificial chamber with the 0.5 mm oversized manual trephine to a depth of 90%. In two cases after DLK was finished, limbal stem cell grafting was additionally performed.

RESULTS

Postoperative NCVA ranged from 0.01 to 0.8 and BCVA from 0.1 to 0.8. Astigmatism ranged from 0.5 to 10.0 D. Refractive error ranged from -8.0 to +1.0 D. In follow-up period all grafts maintained transparent. The complications were mainly intraoperative perforations of Descemet membrane (9 cases): in 7 cases we convert the procedure into penetrating keratoplasty. In 2 cases the double chamber-forming was observed: in one case on 7 day following surgery the penetrating keratoplasty was performed, in other a spontaneous attachment was observed. We also observed loose sutures in 2 cases, inflammatory infiltrates in one case. Two cases of ocular hypertension was successfully treated by medication.

CONCLUSIONS

Deep lamellar keratoplasty is an effective procedure for treating various diseases of corneal stroma with unaffected endothelium.

Mitral valve repair versus mitral valve replacement

Over the past 40 years mitral valve surgery has changed dramatically. After initial enthusiasm with the introduction of valve prostheses in the 1960s, a renewed interest in repair techniques began in the 1970s with the introduction of annuloplasty rings. These repair techniques revealed that the integrity of the subvalvular apparatus plays an important role in left ventricular function. When considering the major series comparing early and late results of mitral valve repair versus prosthetic mitral valve replacement, operative mortality rate is lower for patients with mitral valve repair. Long-term results also show a superior survival rate after mitral valve reconstruction. In addition, several problems can occur with the prosthetic valve, such as thromboembolism and endocarditis. All of these factors favor valve repair over replacement. The success of mitral valve repair depends on many factors: etiology of the mitral valve disease and the resultant pathomorphology of the valve, patient's circumstances such as age or contraindication for anticoagulation, and the experience of the surgeon. The decision whether to repair or replace the mitral valve depends on these factors. Data in the literature and in large collective databases reflect the advantages of mitral valve repair, with over 75% of current mitral valve surgeries being repairs. In the past 5 years the exposure of the mitral valve through a right lateral minithoracotomy using video assistance has developed into a widespread technique. This approach allows complex mitral valve repair as well as mitral valve replacement even with biological stentless prostheses, with decreased morbidity. The addition of radiofrequency ablation for restoration of sinus rhythm enhances the outcome after mitral valve surgery, and can also be easily performed through a minithoracotomy technique.

[Mitral valve repair versus mitral valve replacement]

Over the past 40 years mitral valve surgery has changed dramatically. After initial enthusiasm with the introduction of valve prostheses in the 1960s, a renewed interest in repair techniques began in the 1970s with the introduction of annuloplasty rings. These repair techniques revealed that the integrity of the subvalvular apparatus plays an important role in left ventricular function. When considering the major series comparing early and late results of mitral valve repair versus prosthetic mitral valve replacement, operative mortality rate is lower for patients with mitral valve repair. Long-term results also show a superior survival rate after mitral valve reconstruction. In addition, several problems can occur with the prosthetic valve, such as thromboembolism and endocarditis. All of these factors favor valve repair over replacement. The success of mitral valve repair depends on many factors: etiology of the mitral valve disease and the resultant pathomorphology of the valve, patient's circumstances such as age or contraindication for anticoagulation, and the experience of the surgeon. The decision whether to repair or replace the mitral valve depends on these factors. Data in the literature and in large collective databases reflect the advantages of mitral valve repair, with over 75 % of current mitral valve surgeries being repairs.In the past 5 years the exposure of the mitral valve through a right lateral minithoracotomy using video assistance has developed into a widespread technique. This approach allows complex mitral valve repair as well as mitral valve replacement even with biological stentless prostheses, with decreased morbidity. The addition of radiofrequency ablation for restoration of sinus rhythm enhances the outcome after mitral valve surgery, and can also be easily performed through a minithoracotomy technique.

Dynamics of side-chain liquid-crystalline polymers: a dielectric spectroscopy investigation

We have studied the dynamics in two side-chain liquid-crystalline derivatives of poly(norbornene diethylester) with dielectric spectroscopy within the temperature range 190-433 K and the pressure range 1-3000 bars. Optical microscopy, x-ray scattering, and differential scanning calorimetry (DSC) revealed the formation of a nematic- and a smectic-A phase, respectively, in the polymers with the shorter and longer spacers. Multiple relaxation processes exist originating from the backbone and mesogenic dipoles. In the smectic-A phase two relaxation processes exist above the DSC glass temperature (alpha and alpha(')) which merge with decreasing temperature or with increasing pressure, thus suggesting a common molecular mechanism. The faster process is the segmental (alpha) relaxation associated with the dynamic glass transition, whereas the slower process reflects mainly the side-chain dynamics within the smectic layers. Pressure was found to increase the glass temperature in the nematic and smectic phases and the dT(g)/dP was 18.7 and 16.9 K/kbar, respectively. However, the effect of pressure in inducing the isotropic-to-smectic transition is more drastic as dT(SI)/dP=26.4 K/kbar.

Resection of atherosclerotic aneurysm at origin of aberrant right subclavian artery

In two patients (75- and 88-years-old), with the aid of cardiopulmonary bypass and using a transaortic approach, a rare calcified aneurysm at the origin of an aberrant right subclavian artery was closed with a prosthetic patch. The aneurysm was partially resected and the remainder closed over the patch. This technique obviates the need for hazardous clamping of the aorta around the base of the calcified aneurysm and allows secure closure of the origin of the aneurysm.

Aortic root reconstruction with preservation of native aortic valve and sinuses in aortic root dilatation with aortic regurgitation

BACKGROUND

We assessed the results of a modified technique for aortic root reconstruction including preservation of the native aortic valve and sinuses.

METHODS

A modified technique for reconstruction of the aortic root was devised in which the native aortic sinuses are preserved and remodeled, the diameter of the sinotubular junction is reduced, the ventriculoaortic junction is reinforced with a Dacron prosthesis, and the coronary ostia are reimplanted. Since January 1995, this modified operative technique was performed in 13 patients with a mean age of 54 +/- 21 years. The median grade of aortic regurgitation was 3; in 10 patients it was caused by dilatation of the sinotubular junction, and 3 had additional annuloaortic ectasia.

RESULTS

The aortic crossclamping time was 61 +/- 18 minutes. In-hospital mortality was 2 of 13 (15. 3%) patients, both deaths being related to complications of aortic dissection. In 1 patient aortic regurgitation increased to grade 3, necessitating aortic valve replacement. At a mean follow-up of 2.1 years, the remaining 10 patients had stable aortic valve function with a median grade of regurgitation of 1. The mean New York Heart Association functional class was 1.2.

CONCLUSIONS

Aortic root reconstruction with preservation of the native aortic valve and sinuses allows symmetric reconstruction of the aortic sinuses and adaptation of the diameters of the sinotubular and ventriculoaortic junctions, thus optimizing aortic valve function. Moreover, it prevents contact of the aortic valve leaflets with the Dacron graft, which may enhance the durability of the repair.

Rare fatal simultaneous mould infection of the lung caused by Aspergillus flavus and the basidiomycete Coprinus sp. in a leukemic patient

The basidiomycete Coprinus sp. was isolated repeatedly from bronchial secretions and bronchoalveolar lavage of a 40-year-old woman suffering from a relapse of acute lymphoblastic leukemia 5 years after she underwent autologous bone marrow transplantation. Post-mortem microbiological investigation of lung tissue revealed simultaneously growing Coprinus sp. and Aspergillus flavus. Histopathological examination of the lung demonstrated septate hyphae characteristic of both Aspergillus and Coprinus. The basidiomycete Coprinus sp. should be considered as a potential opportunistic pathogen because of its excellent growth at 37 degrees C.

Disseminated mycosis due to Scedosporium prolificans in an AIDS patient with Burkitt lymphoma

A case of fatal disseminated infection caused by the dematiaceous hyphomycete Scedosporium prolificans diagnosed post mortem is reported in a 60-year-old male patient with acquired immunodeficiency syndrome who additionally suffered from Burkitt's lymphoma. The patient was significantly granulocytopenic following aggressive chemotherapy and irradiation. He developed dyspnoea at rest and chest pain despite a normal chest radiograph. Fluconazole treatment was carried out empirically because no sign of a fungal infection was detected ante mortem, either by mycological cultivation or by serological investigation. First post-mortem examination revealed a disseminated fungal infection involving the central nervous system. Scedosporium prolificans was cultured from the kidney, spleen and myocardium. In vitro, the fungal isolate was found to be highly resistant to all available systemic antimycotics.

[Invasive mold infections in the university clinics of Leipzig in the period from 1992-1994]

Invasive mould infection, e. g. aspergillosis in the first place, is a common infection in immunocompromised patients. The diagnosis of invasive mould infection is difficult in the absence of confirmation by tissue biopsy and histological studies. Therefore, prevalence of invasive mould infections at the School of Medicine of the Leipzig University between 1992 and 1994 was investigated. The diagnosis of invasive mould infection was suspected on clinical, mycological, and radiological findings. The definitive diagnosis was obtained by identification of characteristic mould hyphae on stained smears, and/or positive culture, and/or the detection of Aspergillus antigen (Pastorex) in serum, bronchial secretion, or bronchoalveolar fluid, and confirmed by histopathology. In altogether 21 patients the definitive diagnosis invasive mould infection was recorded, among them 20 invasive aspergilloses. Underlying diseases were leukaemia (n = 11), aplastic anaemia (n = 2), non-Hodgkin-lymphoma (n = 1), systemic lupus erythematosus (n = 1), kidney transplantation (n = 1), peritonitis after Billroth II anastomosis (n = 1), Polymyalgia rheumatica (n = 1), AIDS plus Burkitt lymphoma (n = 1), glioblastoma (n = 1), and subarachnoid haemorrhage (n = 1). As causative fungi were isolated: Aspergillus fumigatus (n = 13), Aspergillus terreus (n = 1), Aspergillus flavus as rare simultaneous injection with the basidiomycete Coprinus spec. in a leukaemic patient (n = 1), and the dematiaceous fungus Scedosporium prolificans in an AIDS patient with Burkitt lymphoma (n = 1). In four patients the invasive mould infection was confirmed histopathologically without isolation and differentiation of the causative agent. Nineteen of the 21 patients with invasive mould infections died corresponding to a mortality rate of 90%.

Peracute disseminated fatal Aspergillus fumigatus sepsis as a complication of corticoid-treated systemic lupus erythematosus

Immunocompromised and granulocytopenic patients and those receiving long-term or high-dose corticoid treatment are predisposed to disseminating Aspergillus infections. However, Aspergillus infection has been described only rarely in patients with autoimmune diseases. We report on a woman suffering from systemic lupus erythematosus treated by antibiotics and high-dose corticosteroids, a primary risk factor, who developed a peracute disseminated fatal Aspergillus fumigatus infection involving the central nervous system. The present case is compared with 10 previous reports of invasive aspergillosis in systemic lupus erythematosus found by a literature search.