A survey of advancements in nucleic acid-based logic gates and computing for applications in biotechnology and biomedicine

Nucleic acid-based logic devices were first introduced in 1994. Since then, science has seen the emergence of new logic systems for mimicking mathematical functions, diagnosing disease and even imitating biological systems. The unique features of nucleic acids, such as facile and high-throughput synthesis, Watson-Crick complementary base pairing, and predictable structures, together with the aid of programming design, have led to the widespread applications of nucleic acids (NA) for logic gate and computing in biotechnology and biomedicine. In this feature article, the development of in vitro NA logic systems will be discussed, as well as the expansion of such systems using various input molecules for potential cellular, or even in vivo, applications.

Short leukocyte telomere length predicts poor prognosis and indicates altered immune functions in colorectal cancer patients

BACKGROUND

Numerous studies indicate that the leukocyte telomere length is associated with the risk of cancers, including colorectal cancer (CRC). However, the prognostic value of leukocyte telomere length in CRC patients has not been investigated.

PATIENTS AND METHODS

Relative telomere length (RTL) of peripheral blood leukocytes (PBLs) from 571 CRC patients receiving surgical resection was measured using a polymerase chain reaction-based method. The Cox proportional hazards ratio model and the Kaplan-Meier curve were used to estimate the association between RTL and the clinical outcome of CRC patients in the training set (90 patients) and the testing set (86 patients). Finally, an independent cohort of 395 patients was used as an external validation set. The immunophenotype of PBLs and the plasma concentration of several immune-related cytokines were determined by flow cytometry and enzyme-linked immunosorbent assay, respectively.

RESULTS

Patients with shorter RTL had significantly poorer overall survival and relapse-free survival than those with longer RTL in the training, testing and validation sets. Furthermore, leukocyte RTL and Tumor-Node-Metastasis (TNM) stage exhibited a significant joint effect in the prognosis prediction of combined CRC patients, indicating that patients with both short RTL and advanced stages had the worst prognosis, when compared with other subgroups. In addition, patients with short RTL showed the higher percentage of CD4(+) T cell and the lower percentage of B cell in peripheral blood mononuclear cells, as well as the lower concentration of plasma transforming growth factor-β1, suggesting a possibility that the immune functions changed with RTL alteration.

CONCLUSIONS

Our study for the first time demonstrates that leukocyte RTL is an independent prognostic marker complementing TNM stage and associated with the immune functions in CRC patients.

Geniculocalcarine tract disintegration after ischemic stroke: a diffusion tensor imaging study

BACKGROUND AND PURPOSE

Our aim was to investigate the disintegration of the geniculocalcarine tract by using DTI-derived parameters in cases of unilateral occipital or temporal-occipital ischemic stroke with geniculocalcarine tract involvement and to determine whether geniculocalcarine tract fibers affected by infarction and unaffected ipsilateral geniculocalcarine tract fibers have different disintegration processes.

MATERIALS AND METHODS

Seventy-one patients underwent routine MR imaging and DTI of the brain. Fractional anisotropy and mean diffusivity of the geniculocalcarine tract fibers affected by infarction, ipsilateral unaffected GCT fibers, and the contralateral geniculocalcarine tract were measured and compared at 5 different time points (from <1 week to >1 year) poststroke.

RESULTS

The fractional anisotropy of geniculocalcarine tract fibers affected by infarction (0.27 ± 0.06) was lower than that of contralateral GCT fibers (0.49 ± 0.03). The fractional anisotropy of geniculocalcarine tract fibers affected by infarction was not different in the first 3 weeks (P = .306). The mean diffusivity of geniculocalcarine tract fibers affected by infarction (0.53 ± 0.14) was lower than that of the contralateral GCT fibers (0.79 ± 0.07) in the first week but higher after the second week (0.95 ± 0.20 to 0.79 ± 0.06). The mean diffusivity gradually increased until it was equal to the mean diffusivity of CSF after the eighth week (2.43 ± 0.26), at which time both the fractional anisotropy and mean diffusivity values stabilized. The fractional anisotropy (0.50 ± 0.04) and mean diffusivity (0.77 ± 0.06) of the ipsilateral unaffected GCT fibers were similar to those of the contralateral GCT fibers (0.50 ± 0.03 and 0.79 ± 0.07) during the first 3 weeks. The fractional anisotropy then gradually decreased (from 0.42 ± 0.03 to 0.27 ± 0.05), while the mean diffusivity increased (from 0.95 ± 0.09 to 1.35 ± 0.11), though to a lesser degree than in the corresponding geniculocalcarine tract fibers affected by infarction.

CONCLUSIONS

The geniculocalcarine tract fibers affected by infarction and the ipsilateral unaffected GCT fibers showed different disintegration processes. The progressive disintegration of geniculocalcarine tract fibers affected by infarction was stable until the eighth week poststroke. The ipsilateral unaffected GCT fibers began to disintegrate at the fourth week, but to a lesser degree than the geniculocalcarine tract fibers affected by infarction.

Levonorgestrel-releasing intrauterine device is an efficacious contraceptive for women with leiomyoma

OBJECTIVE

To evaluate the efficacy of a levonorgestrel-releasing intrauterine device (LNG-IUD) as contraception for women with uterine leiomyoma.

METHODS

Thirty women with uterine leiomyoma requiring contraception were enrolled and had a LNG-IUD inserted. Menstrual blood volume (assessed by a pictorial blood loss assessment chart [PBAC]), haemoglobin concentration, volume of uterus and leiomyoma were determined before and after LNG-IUD insertion.

RESULTS

The median (range) PBAC score was 145.0 (60.0-232.0) before LNG-IUD insertion, which significantly decreased to 44.0 (0.0-99.0) and 36.0 (0.0-90.0) after 6 and 12 months of LNG-IUD use, respectively. Prior to LNG-IUD insertion, the median haemoglobin concentration in patients with anaemia was 100.0 (69.0-109.0) g/l and this increased significantly after 6 and 12 months of LNG-IUD use, to 117.5 (101.0-131.0) g/l and 119.5 (108.0-135.0) g/l, respectively. There were no significant changes in uterine or leiomyoma volumes. No patient became pregnant and there were no severe side-effects; one IUD was expulsed.

CONCLUSION

The LNG-IUD may be a safe and effective contraceptive for women of reproductive age with uterine leiomyoma.

Solitary intracerebral chondroma without meningeal attachment: a case report with review of the literature

Intracranial chondromas are rare, benign cartilaginous tumours that account for < 0.3% of primary intracranial tumours. They usually originate from the basal synchondrosis and are extradural though, extremely rarely, they can be intracerebral. Here the case of a 45-year old female is presented with a solitary intracerebral chondroma located in the right frontal lobe with no meningeal attachment. The epidemiology, aetiology, clinical behaviour, radiological features, histological features and treatment of the case are discussed with a review of previous cases reported in the literature.

Clinically driven design of multi-scale cancer models: the ContraCancrum project paradigm

The challenge of modelling cancer presents a major opportunity to improve our ability to reduce mortality from malignant neoplasms, improve treatments and meet the demands associated with the individualization of care needs. This is the central motivation behind the ContraCancrum project. By developing integrated multi-scale cancer models, ContraCancrum is expected to contribute to the advancement of in silico oncology through the optimization of cancer treatment in the patient-individualized context by simulating the response to various therapeutic regimens. The aim of the present paper is to describe a novel paradigm for designing clinically driven multi-scale cancer modelling by bringing together basic science and information technology modules. In addition, the integration of the multi-scale tumour modelling components has led to novel concepts of personalized clinical decision support in the context of predictive oncology, as is also discussed in the paper. Since clinical adaptation is an inelastic prerequisite, a long-term clinical adaptation procedure of the models has been initiated for two tumour types, namely non-small cell lung cancer and glioblastoma multiforme; its current status is briefly summarized.

Isolated primary non-Hodgkin's lymphoma of the thoracic spine: a case report with a review of the literature

A case of isolated primary non-Hodgkin's lymphoma of the spine is presented along with a review of previous cases reported in the literature. An 80-year old immunocompetent man was admitted with progressive numbness and weakness of both lower extremities of 2 weeks' duration. Magnetic resonance imaging (MRI) of the cervicothoracic spine revealed an extradural spinal mass at the T1 - T3 level, with invasion into the T3 vertebral body. The lesion was at first thought to be a metastatic tumour. Because of the manifestations of compression, the patient underwent laminectomy and posterior decompression. Histopathological examination revealed diffuse large B-cell non-Hodgkin's lymphoma. All other investigations (including computed tomography of the chest and abdomen, bone scan, peripheral blood examination and tumour marker examination) were negative for occult disease. This case demonstrates that neurosurgeons should be aware of the occurrence of isolated primary spinal lymphoma, which should be included in the differential diagnosis of metastatic tumours.