In vivo growth and differentiation potential of tracheal basal cells of rabbits in vitamin A deficiency

The growth and differentiation potential of rabbit tracheal basal cells were investigated in vitamin A deficient mice. Denuded rat tracheal grafts were xenotransplanted into nude mice made vitamin A deficient by feeding them retinol-free pellets from mid-gestation. Rabbit tracheal epithelial cells harvested enzymatically or cells derived from a basal-cell-rich fraction obtained by elutriation (purity 93.3%) had previously been inoculated into the grafts ( n  = 8, each). The grafts were implanted into the vitamin A deficient or control mice aged about 10 weeks. Four weeks later, the grafts were retrieved for histological examination.
The graft epithelium established by either basal cells or un-fractionated cells in vitamin A deficient hosts (groups 1 and 2, respectively) was atrophic, whereas grafts repopulated with both cell types in the controls had pseudostratified columnar epithelium. Group 1 and 2 grafts both showed squamous metaplasia; 10 metaplastic foci in 32 tracheal rings in group 1 ( P  < 0.02 or 0.002, compared with values for group 2 or controls, respectively), and 2 foci in 35 rings in group 2 (no statistical difference compared with controls).
In conclusion, during vitamin A deficiency, rabbit tracheal epithelial cells, including the progeny of highly-purified basal cells, lost their potential for establishing a mucociliary epithelium and rather appeared to undergo squamous metaplasia.     

Five cases of necrotizing fasciitis: Lack of skin inflammatory signs as a clinical clue for the fulminant type

Herein, we describe five patients with necrotizing fasciitis (NF) who had variable outcomes and clinical manifestations. At the onset, all patients exhibited purpura with or without blister and ulceration accompanied by severe pain and tenderness in the affected skin. Out of five patients, three lacked inflammatory signs such as redness and heat, and two of the three patients showed fulminant progression and died despite intensive treatments including surgical debridement, antimicrobial therapy, close monitoring and physiological support. Tissue specimens from the patients without skin inflammatory signs showed mild neutrophil infiltration in addition to necrosis from the epidermis to subcutaneous fat, and variable amounts of thrombi. Furthermore, numerous bacteria were detected by Gram stain. By contrast, the remaining two patients with skin inflammatory signs revealed slower progression, and tissue specimens from both patients showed heavy neutrophil infiltration, but bacteria were hardly detected. Therefore, these cases suggest the possibility that the paucity of skin inflammatory signs, such as redness and heat, in NF may be a clinical clue to predict the fulminant type.     

Type C chronic hepatitis associated with thrombocytopenia in two patients

Abstract Portal hypertension in the presence of chronic hepatitis is generally thought to develop during the progression of the chronic hepatitis to cirrhosis. Before the establishment of assays for diagnosing hepatitis C virus infection, such a case of portal hypertension without liver cirrhosis could be misdiagnosed as idiopathic portal hypertension. It had not fully determined whether portal hypertension might precede the onset of cirrhosis in type C chronic hepatitis. This report presents two cases of women with chronic hepatitis C who developed severe thrombocytopenia; each showed splenomegaly and hypersplenism due to portal hypertension. Angiographic study and histological analysis were conducted to determine the cause of the portal hypertension. Histological evaluation showed an intrahepatic presinusoidal block pattern and fibrotic changes in the periportal area, but no evidence of liver cirrhosis or of other incidental complications such as idiopathic portal hypertension. Both of these patients exhibited normal platelet counts after splenectomy. Thus, type C chronic hepatitis can lead to portal hypertension, as demonstrated in these two patients.     

Immunological responses against an autologous human hepatocellular carcinoma cell line

We performed a detailed analysis of immune responses in a hepatocellular carcinoma (HCC) cell line and effector cells obtained from a patient with HCC. We examined the cytotoxic activity of natural killer (NK) cells, lymphokine-activated killer (LAK) cells and cytotoxic T lymphocytes (CTL) against an autologous tumour cell line (SUHC-1) to investigate the immune mechanism of human lymphocytes against HCC cells. Cytotoxic T lymphocytes were induced by co-culturing of peripheral blood lymphocytes (PBL) and SUHC-1 cells, mixed lymphocyte and tumour cell culture (MLTC). The susceptibility of SUHC-1 to NK and LAK cells was similar to that of other allogeneic cell lines, such as K562, PLC/PRF/5 and Mahlavu. Effector cells induced in the primary MLTC had high cytotoxic acitivity but were not specific for SUHC-1. Cytotoxic T lymphocytes with specific activity against SUHC-1 were induced after PBL were stimulated five times at 7–10 day intervals with SUHC-1 and low-dose recombinant interleukin-2 (rIL-2), suggesting that as the culture progressed, broadly reactive effector cells disappeared and specific effector cells survived. The specific effector cells were identified as CD3⁺/CD4⁺ and CD⁺/CD8⁺ T-lymphocyte subsets. The recognition mechanisms of CD3⁺/CD4⁺ CTL remain unresolved because the cytotoxicities were not inhibited by anti-CD4 and anti-major histocompatibility complex (MHC) class II monoclonal antibodies (MoAb). Treatment of cells with anti-CD3, anti-CD8 and anti-MHC class I MoAb partially inhibited lysis. These results demonstrated that the T-cell receptor (TCR)/CD3 complex appeared to be involved in SUHC-1 specific antigen recognition and antigen recognition of CD3⁺/CD8⁺ CTL was MHC class I restricted.     

WHICH BALANCE EVALUATION SYSTEMS TEST SECTIONS BEST DISTINGUISH LEVELS OF POST-STROKE FUNCTIONAL WALKING STATUS?

ObjectiveTo determine which sections of the Balance Evaluation Systems Test (BESTest) distinguish levels of post-stroke functional walking status and to establish their cut-off scores.DesignA retrospective cross-sectional study.Subjects and methodsThe BESTest was administered to 87 stroke patients who were able to walk without physical assistance upon discharge from the hospital. Subjects were divided into 3 functional walking status groups: namely, household ambulators, limited community ambulators, and unlimited community ambulators. The receiver operating characteristic curve was determined and the cut-off score and area under the receiver operating characteristic curve (AUROC) of each section calculated.ResultsIn the comparison of household and limited community ambulators, the accuracies of all BESTest sections were moderate (AUROC>0.7), and the cut-off scores were 36.1–78.6%. In the comparison of limited and unlimited community ambulators, one section (stability in gait) had high accuracy (AUROC=0.908, cut-off scores=73.8%) and 3 sections (biomechanical constraints, anticipatory postural adjustments, and postural response) had moderate accuracy (AUROC=0.812–0.834, cut-off scores=75.0–83.4%).ConclusionThis study demonstrated that different sections of the BESTest had different abilities to discriminate levels of post-stroke functional walking status, and identified cut-off values for targeted improvement.LAY ABSTRACTThe Balance Evaluation Systems Test (BESTest), a clinical postural control measure, categorizes postural control systems in 6 different sections. This study investigated which sections of the BESTest distinguish levels of post-stroke functional walking status, which, in turn, is based on walking speed. Among the slower walkers, all sections of the BESTest showed moderate relationships to categories of walking status. Among the faster walkers, 4 sections showed moderate to strong relationships and 2 sections showed weak relationships. This study may have clinical implications for rehabilitation aimed at improving functional walking status in individuals with stroke. These findings will help rehabilitation professionals assess postural control in relation to stroke patients’ ability to walk in different settings (e.g. their household or the community) and determine which postural control systems should be prioritized in therapeutic interventions.Key words: stroke, walking speed, postural balance, BESTest

Decline in mobility is one of the major sequelae after a stroke (1). Approximately 30–40% of patients with stroke can engage in only limited community walking (2). Walking speed has been shown to be a valid and reliable measure of functional walking status across the continuum of recovery after stroke (3), which, in turn, is important for enabling the patient to safely perform activities of daily living (ADL). In previous studies, researchers have categorized post-stroke individuals as household ambulators, limited community ambulators, and unlimited community ambulators, based on cut-off scores for comfortable walking speed (4, 5). Recovery of walking speed after stroke is tantamount to recovery of walking ability and is critical to maintaining quality of life.In patients with stroke, walking speed is related to various functions; however, one of its key determinants is postural control. Postural control is a complex ability that involves several sub-systems (6), an observation reinforced by biomechanical studies (7–9). However, a systematic review of the literature did not provide sufficient evidence that postural control training per se improved walking speed in individuals with stroke (10). Postural control training is complex and not specific to individual postural control systems. For efficient assessment and intervention by a physiotherapist, it is recommended that postural control systems more directly related to walking speed, and hence walking function, be identified.The Balance Evaluation Systems Test (BESTest) is a clinical assessment tool that evaluates the examinee’s performance across 6 postural control systems (sections) (11). Therefore, the BESTest assessment results can be used to select interventions that focus on the specific deficits identified in each patient. Reports about the sections of the BESTest are increasing; for instance, each section of the BESTest is reported to have low to moderate accuracy as a fall prediction tool, and the relationships of scores with falls vary among the BESTest sections (12, 13). Effective rehabilitation of postural control to improve walking ability and prevent falls requires a better understanding of the relationship of walking to postural control.Although previous research has demonstrated that specific sections of the BESTest are able to differentiate between slow and fast walking speeds in older adults with hip fractures (14), studies have not yet examined which section(s) of the BESTest can best identify functional walking status in individuals with stroke. A better understanding of the relationship between functional walking status and the sections of the BESTest can guide the selection of interventions that address problems in specific aspects of postural control to improve the walking ability of individuals with stroke. We thus conducted the present cross-sectional study, first, to determine which of the sections of the BESTest can distinguish levels of functional walking status using the 3 walking status groups recently updated by Fulk et al. (5), and secondly, to establish cut-off scores for these sections in post-stroke individuals.