Modified Histopathological Protocol for Poly-ɛ-Caprolactone Scaffolds Preserving Their Trabecular,Honeycomb-like Structure

Poly-ɛ-caprolactone (PCL) is now widely studied in relation to the engineering of bone, cartilage, tendons, and other tissues. Standard histological protocols can destroy the carefully created trabecular and honeycomb-like architecture of PCL scaffolds, and could lead to scaffold fibers swelling, resulting in the displacement or compression of tissues inside the scaffold. The aim of this study was to modify a standard histopathological protocol for PCL scaffold preparation and evaluate it on porous cylindrical PCL scaffolds in a rat model. In 16 inbred Wag rats, 2 PCL scaffolds were implanted subcutaneously to both inguinal areas. Two months after implantation, harvested scaffolds were first subjected to μCT imaging, and then to histopathological analysis with standard (left inguinal area) and modified histopathological protocols (right inguinal area). To standardize the results, soft tissue percentages (STPs) were calculated on scaffold cross-sections obtained from both histopathological protocols and compared with corresponding µCT cross-sections. The modified protocol enabled the assessment of almost 10× more soft tissues on the scaffold cross-section than the standard procedure. Moreover, STP was only 1.5% lower than in the corresponding µCT cross-sections assessed before the histopathological procedure. The presented modification of the histopathological protocol is cheap, reproducible, and allows for a comprehensive evaluation of PCL scaffolds while maintaining their trabecular, honeycomb-like structure on cross-sections.     

Immunologically reactive <Emphasis Type="Italic">M. leprae</Emphasis> antigens with relevance to diagnosis and vaccine development

Background  

Leprosy is a chronic infectious disease caused by Mycobacterium leprae that can manifest a wide variety of immunological and clinical outcomes ranging from potent humoral responses among borderline lepromatous (BL) and lepromatous (LL) patients to strong cellular responses among tuberculoid (TT) and borderline tuberculoid (BT) patients. Until recently, relatively little has been known about the immune responses to individual proteins of M. leprae recognized during leprosy.     

Sleeping position and sudden infant death syndrome (SIDS): effect of an intervention programme to avoid prone sleeping

The proportion of prone sleeping among sudden infant death syndrome (SIDS) victims and infants in general, and the rate of SIDS were prospectively studied in the county of Hordaland, Norway, three years before (1987–89) and three years after (1990–92) a campaign to discourage prone sleeping. Before the campaign, 64% of random reference infants were put prone versus 8% after (p < 0.0001). Concurrently, the rate of SIDS decreased from 3.5 to 1.6 per 1000 live births (63 infants before and 30 after the campaign, p = 0.0002). Prone sleeping was not considered a statistically significant risk factor for SIDS before (OR 2.0,95% CI 0.8–4.5), but was highly significant (OR 11.3,95% CI 3.6–36.5) after the campaign. Prone sleeping is an important risk factor for SIDS, but the association may be missed in epidemiological studies if prone is the predominant sleeping position. Behaviour with regard to sleeping position may be changed rapidly by means of a simple campaign.     

Acute rejection in the elderly recipient: Influence of age in the outcome of kidney transplantation

Since the immune response in older recipientsis weaker they should be less likely to rejecta transplanted organ and should need lessaggressive immunosuppressive treatment. Our aimwas to record the incidence and severity ofepisodes of acute rejection (AR), estimate theinfluence of these events on graft survival ofelderly recipients (60) and to comparethese with that in younger ones.We performed 363 kidney transplants between1/94 and 12/98, and recorded clinical andimmunological data, incidence-severity of ARand cause of graft loss. Patients were dividedinto two groups, according to the age attransplantation: A (<60, n = 281/77.4%) and B( 60, n = 82/22.6%). The percentage ofaging recipients and mean age of donors andrecipients increased throughout the period.Although the incidence of ATN was higher in theolder group (29% vs.19%, p < 0.0001) thenumber of graft biopsies was equal in bothgroups. The incidence of AR was similar, 33.4%vs. 26.8%, pNS. The number of AR episodes perpatient was 0.44 and 0.41 respectively. Theseverity of AR was: Banff grade I: A (40.3%)/B (45.7%) pNS; grade II: A (44.1%)/B(48.57) pNS; grade III: A (15.5%)/B (5.7%)pNS. Younger recipients presented a higherlevel of panel-reactive antibodies (PRA) (4.3%vs. 2.07%, p = 0.01). One-year patient survivalwas 96%/91% (p<0.05) and graft survivalwas 81%/78% (pNS) respectively.The age of recipient does not seem to haveinfluenced the incidence-severity of AR or thegraft survival. Thus immunosuppression shouldbe individualised for each patient and shouldnot depend on the age at transplantation.     

Viral hepatitis in health service workers in the Province of Wielkopolska

Viral hepatitis is the most frequent occupational disease in the health service workers. On the ground of epidemiological data on certifications of occupational diseases, an analysis of morbidity of viral hepatitis was performed. Among viruses that can cause occupational hepatitis there are HAV, HBV and HCV. However, occupational HDV and HGV infections are also possible. In Poland, the number of hepatitis diagnosed as occupational diseases became more stable in the years 1996-1998, whereas morbidity of hepatitis C significantly increased. Such an epidemiological situation could be observed in the area of Wielkopolska and throughout the country. In the former province of Poznań and in the present province of Wielkopolska, occupational hepatitis occurred mostly in nurses. In the nineteen sixties and seventies, the most dramatic increase in the incidence of hepatitis B was noticed in the population of nurses and midwives at the age between 21 and 30 years. This can provide evidence of especially high exposure to infectious factors in this occupational group and of high HBV infectivity. Nowadays, an average age at the time of diagnosis of hepatitis C is somewhat higher. Hepatitis C is usually recognized at the age between 30 and 39 years. A relatively low infectivity of HCV and mostly asymptomatic course of the infection, which delays diagnosis, may provide some explanations of these phenomena. The geographical distribution of stated cases of hepatitis C is difficult to predict and may suggest that some non-medical factors also play a role. Since no specific measures to prevent the incidence of hepatitis C have been developed, a good recognition of HCV reservoir in the population of health service workers (particularly nurses) is one of possible methods to improve the epidemiological situation. It might also be necessary to discuss some limitations in work ability of infected persons. In addition, good training in occupational hygiene and how to handle infectious materials is essential for health service workers.     

Cavitated tumor as a clinical subentity in squamous cell lung cancer patients

Cavity in lung cancer patients is usually attributed to worse prognosis, which could be caused by diagnostic difficulties and late surgery. The aim of this study is to identify cavity as clinical subentity in squamous cell lung cancer (SqCLC) patients. 1094 patients with I0 - III0 of SqCLC underwent surgery with the purpose of radical lobectomy or pneumonectomy. The patients were divided into two groups: 100 patients with cavity (cSqCLC) and 994 with solid tumor (sSqCLC). The clinical, histological and prognostic features were compared for the both groups. The Cox multivariate analysis of the prognostic factors was performed. The survival curves for both groups were compared. cSqCLC patients showed lower body mass and more frequent hemoptoe. They had larger tumors, located peripherically, rarer nodal involvement and atelectasis. Despite the similar cancer stage and the exploratory thoracotomies ratio, cSqCLC patients lived shorter. The survival curves for both groups were different: in all population, for patients after radical surgery and even after exploratory thoracotomy. We conclude that the cavitation in SqCLC patients can be regarded as a separate subentity related to worse prognosis.     

Correlations among prostatic-specific antigen, Gleason score, staging and grading in patients after radical prostatectomy

OBJECTIVES: To evaluate the correlation between Gleason grade, T stage, tumour grade and preoperative prostate-specific antigen (PSA) level (< or > 20 ng/mL) in patients after radical prostatectomy (RP). PATIENTS AND METHODS: The serum total PSA level was measured 3 months before surgery in 87 patients who then underwent RP between 1994 and 2000; the tumour specimens were staged and graded. RESULTS: There were 57 (66%) patients with a PSA level of < 20 ng/mL; in this group only four (7%) patients had a Gleason grade of > 7 and eight (14%) had G3 tumours. Thirty (34%) patients had a PSA level of > 20 ng/mL; in this group only two (7%) patients had a Gleason grade of > 7 and 26 (87%) had G1 and G2 tumours. CONCLUSIONS: These results confirm our previous observations that the PSA level cannot be use as the only factor to indicate RP in patients with prostate cancer, but further evaluation on more patients is needed.     

Identification of the key amino acids of gliai cell line-derived neurotrophic factor family receptor alpha 1 involved in its biological function

Glial cell line-derived neurotrophic factor （GDNF） plays a critical role in neurodevelopment and survival of midbrain dopaminergic and spinal motor neurons in vitro and in vivo. The biological actions of GDNF are mediated by a two-receptor complex consisting of a glycosylphosphatidylinositol-linked cell surface molecule, the GDNF family receptor alpha 1 （GFR alpha 1）, and receptor protein tyrosine kinase Ret. Although structural analysis of GDNF has been extensively examined, less is known about the structural basis of GFR alpha 1 function. In this study, based on evolutionary trace method and relative solvent accessibility prediction of residues, a set of trace residues that are solvent-accessible was selected for site-directed mutagenesis. A series of GFR alpha 1 mutations was made, and PC12 cell lines stably expressing different GFR alpha 1 mutants were generated. According to the survival and differentiation responses of these stable PC12 cells upon GDNF stimulation and the GDNF- GFR alpha 1-Ret interaction assay, residues 152NN153, Arg259, and 316SNS318 in the GFR alpha 1 central region were found to be critical for GFR alpha 1 binding to GDNF and eliciting downstream signal transduction. The single mutation R259A in the GFR alpha 1 molecule simultaneously lost its binding ability to GDNF and Ret. However N152A/N153A or S316A/N317A/ S318A mutation in the GFR alpha 1 molecule still retained the ability to bind with Ret. These findings suggest that distinct structural elements in GFR alpha 1 may be involved in binding to GDNF and Ret.     

Practice MRI: Reducing the need for sedation and general anaesthesia in children undergoing MRI

The aim of this study was to evaluate the effectiveness of a practice magnetic resonance unit, in preparing children to undergo magnetic resonance procedures without general anaesthesia (GA) or sedation. The records of children who attended the practice MRI between February 2002 and April 2004 were retrospectively reviewed. Each record was assessed as to whether the child had passed or failed the practice MRI intervention. Those children who were considered to have passed and were proceeded to a clinical non‐GA MRI had the report of the clinical scan reviewed. If the scan had been reported as non‐diagnostic because of movement artefact it was classified as a failed scan, otherwise it was considered a pass. One hundred and thirty‐four children undertook a practice MRI (age range 4.1–16.1 years, median age 7.7 years, 47% boys) and 120/134 (90%) passed the practice session. In all, 117/120 (98%) subsequently had a clinical non‐GA MRI and 110/117 (94%) passed (median age 7.8 years, 47% boys). Preparation is a safe and effective method to reduce the need for sedation and GA in children undergoing a clinical MRI scan. It provides a positive medical experience for children, parents and staff, and results in cost savings for the hospital.