In vitro chemosensitivity of head and neck cancer cell lines

Background

Systemic treatment of head and neck squamous cell carcinoma (HNSCC) includes a variety of antineoplastic drugs. However, drug-resistance interferes with the effectiveness of chemotherapy. Preclinical testing models are needed in order to develop approaches to overcome chemoresistance.

Methods

Ten human cell lines were obtained from HNSCC, including one with experimentally-induced cisplatin resistance. Inhibition of cell growth by seven chemotherapeutic agents (cisplatin, carboplatin, 5- fluorouracil, methotrexate, bleomycin, vincristin, and paclitaxel) was measured using metabolic MTT-uptake assay and correlated to clinically-achievable plasma concentrations.

Results

All drugs inhibited cell growth in a concentration-dependent manner with an IC50 comparable to that achievable in vivo. However, response curves for methotrexate were unsatisfactory and for paclitaxel, the solubilizer cremophor EL was toxic. Cross-resistance was observed between cisplatin and carboplatin.

Conclusion

Chemosensitivity of HNSCC cell lines can be determined using the MTT-uptake assay. For DNA-interfering cytostatics and vinca alkaloids this is a simple and reproducible procedure. Determined in vitro chemosensitivity serves as a baseline for further experimental approaches aiming to modulate chemoresistance in HNSCC with potential clinical significance.     

De novo 16p13.11 microdeletion identified by high-resolution array CGH in a fetus with increased nuchal translucency

Objective  We investigated the application of high-resolution microarray-based comparative genomic hybridisation (array CGH) on a fetus showing increased nuchal translucency (NT).
Design  Case study.
Setting  Tertiary referral obstetrics unit.
Sample  Pregnant woman attended the antenatal clinic.
Methods  Conventional karyotyping and genetic test was carried out for the alpha-globin gene. High-resolution array CGH using the high-density 244K Agilent microarray was performed on fetal blood sample by cordocentesis to investigate the possibility of any genomic imbalance.
Main outcome measures  Detection of chromosomal abnormality.
Results  Karyotyping analysis showed 46,XY. Molecular genetic diagnosis confirms the fetus has Hb-H constant spring disease but cannot explain the increased NT to 3.2 mm. Array CGH analysis discovered a 1.32-Mb microdeletion on chromosome 16p13.11. Deletion at 16p13.11 has been implicated to predispose to autism and/or mental retardation. Baby was delivered at 40 weeks of gestation, and follow up was carried out at 3 months of age without sign of mental retardation/developmental delay.
Conclusions  This case study demonstrated that array CGH can accurately calibrate the size and identify de novo interstitial chromosome imbalances. However, the presence of chromosome copy variants with unknown clinical significance currently limits its wider scale application in prenatal diagnosis and needs further investigations.     

High-definition imaging of trabeculectomy blebs using spectral domain optical coherence tomography adapted for the anterior segment

Background:  The aim of this work was to image trabeculectomy blebs using spectral domain optical coherence tomography (SDOCT).
Methods:  In this prospective cross-sectional study, patients who had undergone trabeculectomy with at least 3 months of follow up were included. Blebs were imaged using an adapted SDOCT system (Cirrus HD-OCT, Carl Zeiss Meditec Inc., Dublin, CA, USA) and time domain anterior segment optical coherence tomography (ASOCT) (Visante OCT, Carl Zeiss Meditec Inc.). An observer masked to clinical data assessed the utility of SDOCT and ASOCT in visualizing structures in successful and failed blebs.
Results:  Fifty-one eyes were imaged, of which 43 (84.3%) were successful. SDOCT showed wall thickening (93.0% vs. 67.4%, P  = 0.006) and discrete hyporeflective spaces in the wall (88.4% vs. 14.0%, P  < 0.0001) in a greater proportion of successful blebs than ASOCT. SDOCT showed the bleb cavity (23.3% vs. 48.8%, P  = 0.02), scleral flap (34.9% vs. 90.7%, P  < 0.0001), subflap space (20.9% vs . 72.1%, P  < 0.0001) and ostium (9.3% vs. 88.4%, P  < 0.0001) in fewer successful blebs than ASOCT. The internal ostium was not visualized in any failed bleb using SDOCT, whereas ASOCT showed the ostium in 87.5% of failed blebs ( P  = 0.001). SDOCT showed cystic spaces in the bleb wall in a greater proportion of successful blebs than failed blebs (88.4% vs. 37.5%, P  = 0.005).
Conclusions:  SDOCT imaging was able to show fine superficial features in the bleb wall. However, SDOCT had limited clinical utility in that it did not provide useful information about deep features such as flap position, bleb cavity formation or patency of the subflap space and internal ostium.     

Provider perspectives on service delivery modifications to maintain access to HIV pre‐exposure prophylaxis during the COVID‐19 pandemic: qualitative results from a PrEP implementation project in Kenya

IntroductionHIV pre‐exposure prophylaxis (PrEP) is an essential prevention strategy being scaled up for priority populations in Kenya, including for HIV serodiscordant couples. The COVID‐19 pandemic posed challenges to PrEP rollout. We conducted a qualitative study of PrEP providers to understand how clinics adjusted PrEP delivery during the COVID‐19 pandemic.MethodsSince 2017, the Partners Scale‐Up Project has integrated PrEP into 25 HIV clinics in Central and Western Kenya. We conducted qualitative interviews with 40 purposively sampled clinic personnel. We interviewed personnel once during the first pandemic wave (May–Aug 2020) and again after some decline in COVID‐19 rates (Nov–Jan 2021). We analysed data using inductive memo‐writing and summarized data by themes along the PrEP delivery cascade, guided by the Framework for Reporting Adaptation and Modifications (FRAME).ResultsWe interviewed 27 clinical officers, five nurses, four health records and information officers, and four counsellors from Central (n = 20) and Western (n = 20) Kenya. About half (n = 19) were female, with a median age of 32 (IQR: 29–34) and 2.3 years of experience delivering PrEP (IQR: 2–3). All participants reported clinic changes in PrEP demand creation and service delivery during the pandemic. Modifications occurred during PrEP implementation and sustainment phases, were partly reactive to the pandemic and also facilitated by interim Ministry of Health guidance on PrEP delivery during COVID, and were made by PrEP delivery teams, clients and clinic managers. Commonly reported modifications included dispensing multiple‐month PrEP refills, intensifying phone‐based client engagement and collaborating with other HIV clinics to ensure that clients with prolonged stays in other regions could continue to access PrEP. Some clinics also adopted practices to streamline visits, such as within clinical‐room PrEP dispensing, pre‐packing PrEP and task‐shifting. Most providers liked these changes and hoped they would continue after the pandemic subsides.ConclusionsCOVID‐19 served as a catalyst for PrEP delivery innovations in Kenya. HIV clinics successfully and rapidly adapted their PrEP demand creation, refill and retention strategies to promote PrEP uptake and effective use. These modified implementation strategies highlight opportunities to streamline the delivery of PrEP, as well as other HIV and chronic care services, and strengthen engagement with populations post‐pandemic.     

The management of extensive corrosive esophageal strictures: Do not dilate and procrastinate

Corrosive strictures of the esophagus are difficult to treat, however, prompt and appropriate management of corrosive burns to the esophagus can prevent the formation of strictures. In a developing country like India, where facilities for early treatment are not easily available, strictures are an ineviatable consequence. If the strictures are extensive, dilatational therapy proves ineffective and offers no substantial benefit to the patients. Twenty patients with extensive corrosive strictures of the esophagus were surgically managed; by esophageal bypass in 13 and esophagectomy in 7. Surgical treatment restored normal swallowing in all the patients. The common post-operative complications to occur were: pulmonary complications, anastomotic leak and stricture, gastric outlet obstruction and reflux esophagitis. For extensive corrosive strictures of the esophagus, we advocate early surgical treatment rather than prolonged dilatational therapy.     

Evaluation of immune associated cells in lesions of L. major infected vervet monkeys (Cercopithecus aethiops)

Vervet monkeys were used to characterize immune associated cell types recruited into lesion sites as a result of experimental primary and secondary infections with Leishmania major. A heavy cellular infiltration consisting primarily of CD8+ (cytotoxic/suppressor) T cells were observed in the lesions. A small number of B lymphocytes and NK cells were also stained. Changes in cell type populations observed in the lesions were similarly reflected in the draining lymph nodes. Studies from control sites in all the animals revealed the presence of CD8+ T cells both in the epidermis and dermal layers of the normal skin. B cells, CD16 (NK cells) and CD4 (helper T cells) positive cells were virtually absent in the normal skin. It was concluded that CD8+ T cells were the predominant cells in the lesions. It also appeared that similar cell types were restricting the parasites at the lesion site both in primary and secondary L. major infections in vervet monkeys.