Frequent ongoing T-cell receptor rearrangements in childhood B- precursor acute lymphoblastic leukemia: implications for monitoring minimal residual disease

Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.     

Spermicidal activity of chelated complexes of bis(cyclopentadienyl)vanadium(IV)

Transition metal complexes containing vanadium IV have been shown to modulate the cellular redox potential and catalyse the generation of reactive oxygen intermediates (ROI). Since sperm function is exquisitely susceptible to ROI, we examined the effects of stable chelate complexes of vanadocenes on human sperm motility. We synthesized seven structurally distinct chelate complexes of bis(cyclopentadienyl)vanadium(IV) with bidentate ligands [i.e. vanadocene acetylacetonato monotriflate (VDacac), vanadocene hexafluoro acetylacetonato monotriflate (VDHfacac), vanadocene N-phenyl benzohydroxamato monotriflate (VDPH), vanadocene acethydroxamato monotriflate (VDH), vanadocene catecholate (VDCAT), vanadocene bipyridino ditriflate (VDBPY), and vanadocene dithiocarbamate monotriflate (VDDTC)], and evaluated their spermicidal activity using computer-assisted sperm analysis (CASA; Hamilton-Thorne). All seven chelate complexes of vanadocene elicited potent spermicidal activity at micromolar concentrations (EC50 values: 3.9-106 microM) without affecting the sperm acrosome integrity. The catecholate and acetylacetonate complexes of vanadocene were the most active and the bipyridyl complex the least active with an order of efficacy VDCAT > VDacac > VDDTC > VDPH > VDH > VDHfacac > VDBPY. The spermicidal activity of chelate complexes of vanadocenes was rapid and irreversible since the treated spermatozoa underwent apoptosis, as determined by the flow cytometric analysis of mitochondrial membrane potential, surface annexin V binding assay, in-situ nick-end labelling of sperm nuclei, and confocal laser scanning microscopy. These results provide unprecedented evidence that chelate complexes of vanadocene with bidentate ligands have spermicidal and apoptosis inducing properties. These vanadocene complexes, especially VDacac, may be useful as contraceptive agents.      

Clinical utility of plain-film abdominal radiographs for inpatients outside standard working hours in a large university teaching hospital

IntroductionPlain film abdominal radiographs (PFAs) are frequently the initial investigation ordered for patients with abdominal symptoms. However, increasing use of emergency ultrasound and availability of emergency CT raises the question of whether PFA remains an appropriate first line investigation. We investigated the impact of out of hours (OOH) PFAs on inpatient management.MethodsAll consecutive PFAs over an 8-week period were included to determine the impact on patient management. OOH was classified as from 5pm to 9am Monday to Friday, weekends and bank-holidays. PACS and hospital records were accessed to determine patient pathways. The institution is a tertiary referral centre with 850 acute beds and serves a population of 950,000.ResultsA total of 758 consecutive PFAs were performed in total (58.3% male, mean age 58.1 (range 0–93)). 310 (40.9%) were requested from the emergency department (ED) and 382 (50.4%) were requested from wards. 160 (21.1%) met the criteria of OOH, of these 120 (72.2%) were from ED and 28 were on adult inpatients. Of these 28, none had a change in management based on the PFA result.ConclusionOur study suggests that OOH PFAs of inpatients are of limited clinical utility. These patients are exposed to extra radiation.Implications for practiceWe propose that OOH PFAs of inpatients should be questioned as a viable investigation due to the limited contribution they offer in managing patients, the deleterious effects they confer on the patient and the associated economic cost. Further studies are needed to assess if these results are generalizable to other large hospitals.     

Regulation of erythropoietin production in a human hepatoblastoma cell line

Production of immuno and biologically active erythropoietin was documented to occur in the human hepatoblastoma cell line HepG-2. The expression of the erythropoietin gene was further verified by Northern blot analysis using a single stranded RNA probe. In vitro studies showed that erythropoietin production by these cells was not stimulated by hypoxia or cobalt chloride, but was related to the proliferative activity of the cells in culture. In addition it was found that the secretion of erythropoietin was almost completely abrogated by tunicamycin, an inhibitor of N-linked glycosylation. This effect of tunicamycin was also observed in a permanently transfected cell line that secretes erythropoietin in large quantities.     

Comparing human and mouse salivary glands: A practice guide for salivary researchers

Mice are a widely utilized in vivo model for translational salivary gland research but must be used with caution. Specifically, mouse salivary glands are similar in many ways to human salivary glands (i.e., in terms of their anatomy, histology, and physiology) and are both readily available and relatively easy and affordable to maintain. However, there are some significant differences between the two organisms, and by extension, the salivary glands derived from them must be taken into account for translational studies. The current review details pertinent similarities and differences between human and mouse salivary glands and offers practical guidelines for using both for research purposes.     

Increased use of multidisciplinary treatment modalities adds little to the outcome of rectal cancer treated by optimal total mesorectal excision

Purpose

Total mesorectal excision (TME) is the standard surgical treatment for rectal cancer. The roles of chemotherapy and radiotherapy have become more defined, accompanied by improvements in preoperative staging and histopathological assessment. We analyse our ongoing results in the light of changing patterns of treatment over consecutive time periods.

Methods

In total, 151 consecutive patients underwent potentially curative rectal excision for cancer in a single institution. Management and outcomes were compared between 1993–1999 and 2000–2007 which corresponded with the restructuring of the regional oncological services.

Results

We found an increase in patients treated with neoadjuvant chemoradiotherapy after 1999 (20/89 vs 1/62, p?p?=?0.037). The locoregional recurrence rate was 5.3%. The rates were not significantly different between the two study periods [4/89 (4.5%) 1999–2007 vs 4/62 (6.5%) 1993–1999, p?=?0.597]. There was no statistical difference in overall or disease-free survival in the time periods examined.

Conclusions

Increasing use of neoadjuvant therapy and concomitant improvement in lymph node assessment did not translate into a concurrent reduction in the local recurrence, disease-free and overall survival rates. Our results demonstrate the enduring benefit of specialist training in TME in the outcome of rectal cancer surgery. This observational study suggests that low local recurrence rates are surrogate markers for improved overall and disease-free survival. Multidisciplinary team practice should be examined and made cost effective according to the individual unit’s local recurrence rate in the light of this and other reports.     

Current cell models for bioengineering a salivary gland: a mini‐review of emerging technologies

Oral Diseases (2013) 19 , 236–244 Saliva plays a major role in maintaining oral health. Patients afflicted with a decrease in saliva secretion (symptomatically, xerostomia) exhibit difficulty in chewing and swallowing foods, tooth decay, periodontal disease, and microbial infections. Despite recent improvements in treating xerostomia (e.g., saliva stimulants, saliva substitutes, and gene therapy), there is a need of more scientific advancements that can be clinically applied toward restoration of compromised salivary gland function. Here we provide a summary of the current salivary cell models that have been used to advance restorative treatments via development of an artificial salivary gland. These models represent initial steps toward clinical and translational research, to facilitate creation of clinically safe salivary glands. Further studies in salivary cell lines and primary cells are necessary to improve survival rates, cell differentiation, and secretory function. Additionally, the characterization of salivary progenitor and stem cell markers are necessary. Although these models are not fully characterized, their improvement may lead to the construction of an artificial salivary gland that is in high demand for improving the quality of life of many patients suffering from salivary secretory dysfunction.     

Asynchronous globin chain synthesis in rabbit reticulocyte lystates induced by hemin-controlled repressor

To define further the role of hemin-controlled repressor (HCR) in globin synthesis, we studied its effect on the synthesis of individual globin chains in a rabbit reticulocyte lysate cell-free system. In the presence of HCR there was a marked globin chain imbalance, resulting in a lowered alpha/beta ratio. These findings in vitro may have relevance to certain clinical heme deficiency states in which a similar globin chain imbalance has been observed.     

Operative and functional results of total mesorectal excision with ultra-low anterior resection in the management of carcinoma of the lower one-third of the rectum.

Eighty-one patients underwent anterior resection with curative (n = 57) or palliative (n = 24) intent for tumors below 7 centimeters from the anal verge. If a right angled clamp could be applied below the tumor at operation after full mobilization of the mesorectum and rectum, the procedure was performed in preference to abdominoperineal excision. The mean follow-up time was 4.8 years. Of the curative group, 26 had lesions within 5 centimeters of the anal verge. Thirty-one per cent were Dukes' A; 37 per cent, B, and 32 per cent, C lesions. The margin of distal clearance ranged from 2 to 35 millimeters. In five patients, squamous mucosa was observed in the distal doughnut. Serious postoperative complications occurred in 17 per cent of the curative series, one-half of which occurred within the first two years of the study period. In six patients, the temporary colostomy has not been closed. The incidence of local recurrence in the curative series was 3.5 per cent, and the over-all survival rate was 81 per cent at five years. Full continence was achieved within two years of closure of the colosomy in 85 per cent of the patients. In the palliative group, 11 of the 19 patients had temporary colostomies and 80 per cent were continent within six months of operation. The technique of total mesorectal excision and sphincter preservation by stapled coloanal anastomosis in the treatment of carcinomas of the lower one-third of the rectum may be an alternative to abdominoperineal excision. The final decision in such instances is made intraoperatively. The operative and functional results are satisfactory, but it is difficult to anticipate the patients who will not do well by preoperative criteria. Even in palliative procedures, low anterior resections provided satisfactory continence. Serious postoperative complications were more likely to occur if full mobilization of the splenic flexture was not routinely performed.     

Experience of surgery for rectal cancer with total mesorectal excision in a general surgical practice

BACKGROUND: Results from specialist centres have shown that total mesorectal excision (TME) produces excellent control of local disease in patients with carcinoma of the rectum. METHODS: The results of TME were reviewed in a surgical practice in which patients with rectal cancer comprised 1 per cent of the total caseload and mean case numbers were less than 15 each year. RESULTS: Eighty-two consecutive patients underwent rectal excision with TME over a 72-month period (68 anterior resection, eight abdominoperineal excision and six Hartmann's procedure). Sixty-nine operations were deemed 'curative' at the time of surgery. Anastomotic leak occurred in two (3 per cent) of 68 patients, both of whom recovered without additional surgery. There were two local recurrences (3 per cent) among 69 patients who underwent 'curative' surgery. At a median follow-up of 190 weeks, the survival rate for Dukes' stage A, B, C and 'D' was 100, 83, 68 and 18 per cent respectively. CONCLUSION: Outcome as measured by perioperative morbidity and local disease control achieved in a surgical practice with a broad case mix and relatively low annual case volume was comparable to that from larger centres. Appropriate surgical training and attention to technical detail may be as important as case volume in determining outcome after surgery for rectal cancer.