Review: bioprinting: a beginning

An increasing demand for directed assembly of biologically relevant materials, with prescribed three-dimensional hierarchical organizations, is stimulating technology developments with the ultimate goal of re-creating multicellular tissues and organs de novo. Existing techniques, mostly adapted from other applications or fields of research, are capable of independently meeting partial requirements for engineering biological or biomimetic structures, but their integration toward organ engineering is proving difficult. Inspired by recent developments in material transfer processes operating at all relevant length scales--from nano to macro--which are amenable to biological elements, a new research field of bioprinting and biopatterning has emerged. Here we present a short review regarding the framework, state of the art, and perspectives of this new field, based on the findings presented at a recent international workshop.     

Association of HLA-G*01:01:02:01/G*01:04:01 polymorphism with gastric adenocarcinoma

Human leukocyte antigen-G (HLA-G) plays an important role in tumor cell escape from immune surveillance and HLA-G polymorphisms might service as a potential risk factor for clinical outcomes in GAC (gastric adenocarcinoma). We investigated the association between HLA-G polymorphisms as well as soluble HLA-G level and accordance of GAC. This case-control study included 100 GAC patients and 102 unrelated Iranian individual’s samples as control. The clinical stages ranged from I to IV. PCR-RFLP method was carried out in order to specify the genotypes of the HLA-G gene. Concentrations of sHLA-G in serum were determined with the sHLA-G-specific enzyme linked immunosorbent assay (ELISA) kit. The G*01:04:01 and G*01:01:02:01 alleles were the predominant alleles in GAC patients and healthy controls. The G*01:01:03:01 and G*01:01:08 allele distributions are significantly higher among controls comparing to cases and seem to have protective effect (P value = 0.026 and 0.007 respectively). There is a substantial differences in G*01:01:02:01/G*01:04:01 genotype frequencies between cases and controls (OR = 2.8, P value < 0.001). The G*01:01:03:01/G*01:04:01 and G*01:01:02:01/G*01:01:08 genotypes frequency are higher among controls in comparison to patients (P value = 0.028 and 0.007 respectively). The polymorphisms in HLA-G could affect GAC induction and its outcome. Also, increased sHLA-G levels in serum might be a useful biomarker for diagnosis.     

Characterization of three new HLA-B alleles: B*35:05:03, B*52:29 and B*57:01:13

Three new HLA-B alleles were identified during routine sequence-based typing.     

Two novel HLA-A alleles: HLA-A*31:01:09 and HLA-A*33:30

The HLA-A*31:01:09 differs from the closest allele HLAA*31:01:02 by a C to T silent substitution at position 447 in exon 3. The HLA-A*33:30 differs from the closest allele HLA-A*33:03:01 by a single nucleotide substitution at position 453 in exon 3, leading to a change of Arg 131 Cys.     

Surgery: Sterilization reversal: fertility results

Fertility outcome following sterilization reversal by laparotomywas evaluated. We studied all sterilization reversals performedbetween January 1978 and December 1991; a total of 226 womenwere treated. Tubal anastomosis was performed according to therules for microsurgery. The microsurgical technique comprisedtwo main phases: preparation of the healthy tube segments andthe anastomosis carried out on two layers. It was possible tostudy the subsequent fertility of 206 patients in all, as 20patients were lost to follow-up (8.8%). Cumulative pregnancyrates were evaluated by life-table analysis. The overall intrauterinepregnancy rate, including births and miscarriages, was 69.9%(144 patients) after 2 years. The cumulative intrauterine pregnancyrate was 62% at 18 months. Analysis of the fertility resultsdemonstrated that age was the most significant predictive factor.The cumulative intrauterine pregnancy rate at 2 years was 83.5%(61 cases) for patients 33 years, 70% (35 cases) for patientsaged 34–36 years, 62.5% (30 cases) for patients aged 37–39years, and 51.4% (18 cases) for patients aged 40 years. Evenfor patients aged 40 years, microsurgical repermeabilizationcan be retained as the first choice rather than in-vitro fertilization.