Reanimating Pancreatic Grafts Subjected to Prolonged Cold Ischemic Injury Using Normothermic Ex Vivo Perfusion

Background

Pancreas transplant volumes are limited because of poor utilization of "extended criteria grafts." Prolonged cold ischemia is a risk factor associated with poor allograft survival. We aimed to establish the feasibility of transplantation using grafts subjected to prolonged cold ischemia and determine whether these grafts could be optimized using normothermic ex vivo perfusion (NEVP) in a porcine model.

Methods

The study population consisted of 35 to 40 kg male Yorkshire pigs in an allotransplantation model with a 3-d survival plan for recipients. Control grafts were subjected to cold storage (CS) in a University of Wisconsin solution for 21 to 24 h (n = 6), whereas the test group received an additional 3 h NEVP after CS of 21 h (n = 5).

Results

The 3-d survival was 60% in the NEVP arm versus 0% in the control arm (P = 0.008; log rank). Graft parenchyma was 60% to 70% preserved in the NEVP arm at necropsy on gross appearance. In addition, the islet function was well preserved, and both the pancreas (including the islets) and the duodenal morphology were maintained histologically. The intravenous glucose tolerance test on the day of euthanasia was in the normoglycemic range for 80% of cases in the NEVP arm.

Conclusions

Optimization of pancreas grafts exposed to extended CS with NEVP seems promising at rescuing and reanimating these grafts for transplantation, resulting in significantly improved survival in a porcine pancreas transplant model.

Mucormycosis in Liver Allograft Following Transplant for Secondary Biliary Cirrhosis

Mucormycosis, a group of opportunistic mycoses caused by Mucorales, present a significant threat to immunocompromised patients. In this report, we present the case of a 57-year-old male patient who underwent liver transplant for secondary biliary cirrhosis following inadvertent bile duct injury. Despite initial satisfactory postoperative evolution, the patient developed fever, and imaging revealed a suspicious lesion. Preliminary culture growth suggested a filamentous fungus, leading to initiation of liposomal amphotericin B. However, the lesion progressed, and a surgical debridement was necessary. During surgery, involvement of the liver dome and diaphragm was observed, and a nonanatomical hepatectomy was performed. Despite efforts, the patient's condition deteriorated, ultimately resulting in multiple organ failure and mortality. This case emphasizes the challenging nature of mucormycosis in livertransplant recipients.

Combining Oxygenated Cold Perfusion With Normothermic Ex Vivo Perfusion Improves the Outcome of Donation After Circulatory Death Porcine Kidney Transplantation

BACKGROUND

Ex vivo machine perfusion is a novel preservation technique for storing and assessing marginal kidney grafts. All ex vivo perfusion techniques have advantages and shortcomings. The current study analyzed whether a combination of oxygenated hypothermic machine perfusion (oxHMP) followed by a short period of normothermic ex vivo kidney perfusion (NEVKP) could combine the advantages of both techniques.

METHODS

Porcine kidneys were exposed to 30 min of warm ischemia followed by perfusion. Kidneys underwent either 16-h NEVKP or 16-h oxHMP. The third group was exposed to 16-h oxHMP followed by 3-h NEVKP (oxHMP + NEVKP group). After contralateral nephrectomy, grafts were autotransplanted and animals were followed up for 8 d.

RESULTS

All animals survived the follow-up period. Grafts preserved by continuous NEVKP showed improved function with lower peak serum creatinine and more rapid recovery compared with the other 2 groups. Urine neutrophil gelatinase-associated lipocalin, a marker of kidney injury, was found to be significantly lowered on postoperative day 3 in the oxHMP + NEVKP group compared with the other 2 groups.

CONCLUSIONS

A short period of NEVKP after oxHMP provides comparable short-term outcomes to prolonged NEVKP and is superior to oxHMP alone. A combination of oxHMP with end-ischemic NEVKP could be an attractive, practical strategy to combine the advantages of both preservation techniques.

Normothermic Ex Vivo Machine Perfusion of Discarded Human Pancreas Allografts: A Feasibility Study

Pancreas transplantation is the only curative treatment for patients with complicated diabetes, and organ shortage is a common and increasing problem. Strategies to expand the donor pool are needed, and normothermic ex vivo perfusion of the pancreas has the potential to test and repair grafts before implantation. Between January 2021 and April 2022, six human pancreases, declined for transplantation or islet isolation, were perfused using a previously established method by our group. All 6 cases were successfully perfused for 4 h, with minimal edema. The mean age of the donors was 44.16 ± 13.8 years. Five grafts were obtained from neurological death donors, and one was obtained from a donation after cardiac death. The mean glucose and lactate levels decreased throughout perfusion and insulin levels increased. All 6 grafts were metabolically active during perfusion and histopathology showed minimal tissue injury and no edema. Human normothermic ex vivo perfusion of the pancreas is feasible and safe and has the potential to expand the donor pool. Future studies will focus on tests and biomarkers for the assessment of grafts.

Medical Assistance in Dying (MAiD) as a Source of Liver Grafts: Honouring the Ultimate Gift

OBJECTIVE

To report the clinical outcomes of liver transplants from donors after medical assistance in dying (MAiD) versus donors after cardiac death (DCD) and deceased brain death (DBD).

SUMMARY BACKGROUND DATA

In North America, the number of patients needing liver transplants exceeds the number of available donors. In 2016, MAiD was legalized in Canada.

METHODS

All patients undergoing deceased donor liver transplantation at Toronto General Hospital between 2016 and 2021 were included in the study. Recipient perioperative and postoperative variables and donor physiological variables were compared among 3 groups.

RESULTS

Eight hundred seven patients underwent deceased donor liver transplantation during the study period, including DBD (n=719; 89%), DCD (n=77; 9.5%), and MAiD (n=11; 1.4%). The overall incidence of biliary complications was 6.9% (n=56), the most common being strictures (n=55;6.8%), highest among the MAiD recipients [5.8% (DBD) vs. 14.2% (DCD) vs. 18.2% (MAiD); P =0.008]. There was no significant difference in 1 year (98.4% vs. 96.4% vs. 100%) and 3-year (89.3% vs. 88.7% vs. 100%) ( P =0.56) patient survival among the 3 groups. The 1- and 3- year graft survival rates were comparable (96.2% vs. 95.2% vs. 100% and 92.5% vs. 91% vs. 100%; P =0.37).

CONCLUSION

With expected physiological hemodynamic challenges among MAiD and DCD compared with DBD donors, a higher rate of biliary complications was observed in MAiD donors, with no significant difference noted in short-and long-term graft outcomes among the 3 groups. While ethical challenges persist, good initial results suggest that MAiD donors can be safely used in liver transplantation, with results comparable with other established forms of donation.

Outcomes of pancreas transplantation in patients with underlying inflammatory bowel disease (IBD): a retrospective case series

Despite having emerged as a definitive treatment for diabetes mellitus (DM), pancreas transplantation remains a formidable surgical task owing to complications like graft pancreatitis, enteric leaks, and rejection. This becomes more challenging in the setting of underlying bowel pathology, such as inflammatory bowel disease (IBD), which has a strong immune-genomic association of co-existence with DM. Risk of anastomotic leaks, dose adjustments of immunosuppressants and biologicals, and management of IBD flares constitute some of the major perioperative challenges calling for a protocol-based, systematic, multidisciplinary approach.

Patients and methods

This was a retrospective case series of patients between January 1996 and July 2021, with all patients being followed up until December 2021. All consecutive patients with end-stage DM who underwent pancreas transplantation (alone, simultaneous with kidney transplantation or after kidney transplantation) and had pre-existing IBD were included in the study. A Comparison of 1-, 5-, 10-year survival was done with pancreas transplant recipients without underlying IBD using Kaplan-Meir curves.

Results

Of the total 630 pancreas transplants performed between 1996 and 2021, eight patients had IBD, mostly Crohn's disease. Following pancreas transplantation, two of the eight patients had duodenal leaks, with one a requiring graft pancreatectomy. The 5-year graft survival rate for the cohort was 75% compared to 81.6% for the overall cohort of patients undergoing pancreas transplantation (P=0.48) with a median graft survival of 48.4 months compared to 68.1 months in the latter (P=0.56).

Conclusion

The findings of the series provide a snapshot of the outcome of pancreas transplantation in the background of IBD, suggesting a graft and overall patient survival rates comparable with pancreas transplantation in patients without underlying IBD, with further validation of the findings required in a larger cohort of patients in the future.

Intubation, Central Venous Catheter, and Arterial Line Placement in Swine for Translational Research in Abdominal Transplantation Surgery

Translational surgical research models in swine are crucial for developing safe preclinical protocols. However, the success of the experimental surgeries does not solely rely on the research team's surgical skills; perioperative care and management procedures, like intubation, central venous line, and arterial line placement, are necessary and of the utmost importance for favorable experiment results. As it is uncommon for research teams to have anesthesiologists or any other staff other than the surgical team, the surgical team involved in translational research must acquire and/or develop the skills to perform the perioperative care. The purpose of this paper is to show the techniques of intubation, central venous catheter, and arterial line placement used and perfected at the Toronto Organ Preservation Laboratory over the last 10 years, to be used as a reference for future researchers joining either this team or any other lab performing translational research protocols in swine and/or abdominal transplantation.

Normothermic ex situ pancreas perfusion for the preservation of porcine pancreas grafts

Pancreas transplantation improves and extends the life of patients with insulin-dependent diabetes. Pancreata from extended criteria donors have been increasingly used due to the scarcity of available grafts. Normothermic ex situ pancreas perfusion (NESPP) can keep grafts metabolically active, potentially allowing for assessment and organ repair, and could improve outcomes of marginal grafts. A novel NESPP technique was developed and tested. Porcine pancreata were removed after a short period of warm ischemia and subjected to 6 h of NESPP. Perfusion parameters, potential graft assessment markers and graft injury were measured. Next, pancreata subjected to 3 h of NESPP were transplanted and animals were followed for up to 3 days. Graft function and injury post-transplantation were evaluated. Using this novel system of perfusion, pancreata were perfused for an extended period of time with minimal edema. Histology at the end of perfusion showed intact islet cells with only mild signs of tissue injury. NESPP transplanted grafts showed immediate function after transplantation, with glucose levels in normal range. NESPP maintains a physiologic environment and excellent graft function without causing significant graft injury. Porcine pancreas transplantation is feasible and allows for in vivo graft assessment of pancreas function and injury after NESPP.

Chemotherapy in Metastatic Nonanaplastic Thyroid Cancer: Experience at the Institut Gustave-Roussy

Forty-nine patients with metastatic nonanaplastic thyroid carcinoma were treated over a 10-year period. Five successive chemotherapeutic protocols were used: a combination of doxorubicin, etoposide, 5-fluorouracil and cyclophosphamide; elliptinium acetate; doxorubicin; cispiatin; and the combination of doxorubicin and cispiatin. Results obtained with the different protocols were very disappointing, with only two objective responses (3%). Phase II trials with new chemotherapeutic agents are warranted in selected cases of nonanaplastic metastatic thyroid carcinoma.

Asselineau, Léon Auguste

Tumour specimens from 23 patients with thyroid carcinoma, 22 patients with thyroid adenoma, 3 with Graves' disease, and tissues from 8 normal thyroid glands were analyzed by Southern blot hybridization for the physical state of c-myc and c-fos proto-oncogenes. In 4 patients, both the primary tumour and lymph node metastases were analyzed. No amplification or rearrangement of the two proto-oncogenes was detected. Total RNAs were also analyzed. Elevated levels of the 2.4 kb c-myc RNA and of the 2.2 kb c-fos RNA were found in 13/23 (57%) and 14/23 (61%) of the cancer patients, respectively. High levels of c-myc transcripts were more frequently found in thyroid carcinomas with unfavourable prognosis. Concomitant elevated levels of both c-myc and c-fos RNAs were found in 8 cancers. High levels of c-myc RNA were also found in 1 out of 22 specimens of adenoma, in 1 specimen of Graves' disease and in 2 normal thyroid glands. High levels of c-fos RNA were found in 20 of the 22 adenoma samples and in 2 out of 8 normal thyroid tissues. These data indicate that the overexpression of c-myc and c-fos genes is independent of an alteration of the loci. The high levels of c-fos found in adenoma may be associated with the differentiation state of these tumours.

Clinical and dimensional characteristics of euthymic bipolar patients with or without suicidal behavior

BACKGROUND

The clinical and dimensional features associated with suicidal behaviour in bipolar patients during euthymic states are not well characterised.

METHODS

In a sample of 652 euthymic bipolar patients, we assessed clinical features with the Diagnostic Interview for Genetics Studies (DIGS) and dimensional characteristics with questionnaires measuring impulsivity/hostility and affective lability/intensity. Bipolar patients with and without suicidal behaviour were compared for these clinical and dimensional variables.

RESULTS

Of the 652 subjects, 42.9% had experienced at least one suicide attempt. Lifetime history of suicidal behaviour was associated with being a woman, a history of head injury, tobacco misuse and indicators of severity of bipolar disorder including early age at onset, high number of depressive episodes, positive history of rapid cycling, alcohol misuse and social phobia. Indirect hostility and irritability were dimensional characteristics associated with suicidal behaviour in bipolar patients, whereas impulsivity and affective lability/intensity were not associated with suicidal behaviour.

LIMITATIONS

This study had a retrospective design with no replication sample.

CONCLUSIONS

Bipolar patients with earlier onset, mood instability (large number of depressive episodes, rapid cycling) and/or particular addictive and anxiety comorbid disorders might be at high risk of suicidal behaviour. In addition, hostility dimensions (indirect hostility and irritability), may be trait components associated with suicidal behaviour in euthymic bipolar patients.

JC human polyomavirus (JCV) and Epstein-Barr virus (EBV) replicative activities are detected in Hodgkin/Reed Sternberg cells (HRS) and circulating lymphocytes (PBL) of Hodgkin lymphoma (HL) and associated with relapse, especially in younger patients

7551

Background: The HRS derive from germinal-center B-cells, potential sites for latency and reactivation of JCV in immunosuppressed individuals. Replication of human polyomaviruses (JC, BK, SV40) and EBV was assessed in Hodgkin (HL) and B cell non-Hodgkin (B-NHL) lymphomas. Methods: FISH, immunohistochemistry for oncogenic proteins, PCR and DNA sequencing to identify polyomaviruses and EBV on involved nodes and in PBL before, during and after treatment (N = 73 HL, 91 B-NHL). Controls were 30 healthy donors, 70 solid tumors and 14 acute leukemia patients. Results: using FISH, JCV and EBV DNA were detected in all lymphoma nodes. High genome copy number of JCV and EBV were present in 60% and 63%, respectively, in HL patients versus 11% and 14% in B-NHL patients (P < 10−6; P < 10−5). Using nest-PCR, JCV DNA sequencing after laser capture microdissection identified the presence and specificity of JCV sequences in HRS. T antigen and LMP1 co-expression, in 34% of HRS, was associated with early HL relapse (P < 10−4), particularly in young patients (P < 10−5). Only in HL patients PBL, genome copy number of JCV increased significantly during treatment (42%). Rogue cells (cultured lymphocytes with multiple complex chromosomal aberrations indicative of genomic instability) appeared in 40% of patients, and correlated with relapse (p < 10−4). The same JCV sequences were found in tumor cells and PBL of HL patients. Co-genomic replication of EBV and JCV was highly correlated in lymph nodes and in PBL in HL. Conclusions: JCV genomic replication was detected for the first time in HRS, and associated to rogue cell emergence in PBL. Co-detections of JCV and EBV genomic replication in HRS and PBL are associated with relapse, especially in young patients. HRS and PBL JCV/EBV infections are linked and worth further studies.

No significant financial relationships to disclose.

Caudal neurosecretory system of the zebrafish: ultrastructural organization and immunocytochemical detection of urotensins

The caudal neurosecretory system is described here for the first time in the zebrafish, one of the most important models used to study biological processes. Light- and electron-microscopical approaches have been employed to describe the structural organization of Dahlgren cells and the urophysis, together with the immunohistochemical localization of urotensin I and II (UI and UII) peptides. Two latero-ventral bands of neuronal perikarya in the caudal spinal cord project axons to the urophysis. The largest secretory neurons (approximately 20 microm) are located rostrally. UII-immunoreactive perikarya are much more numerous than those immunoreactive for UI. A few neurons are immunopositive for both peptides. Axons contain 75-nm to 180-nm dense-core vesicles comprising two populations distributed in two axonal types (A and B). Large dense vesicles predominate in type A axons and smaller ones in type B. Immunogold double-labelling has revealed that some fibres contain both UI and UII, sometimes even within the same neurosecretory granule. UII is apparently the major peptide present and predominates in type A axons, with UI predominating in type B. A surprising finding, not previously reported in other fish, is the presence of dense-core vesicles, similar to those in neurons, in astrocytes including their end-feet around capillaries. Secretory type vesicles are also evident in ependymocytes and cerebrospinal-fluid-contacting neurons in the terminal spinal cord. Thus, in addition to the urophysis, this region may possess further secretory systems whose products and associated targets remain to be established. These results provide the basis for further experimental, genetic and developmental studies of the urophysial system in the zebrafish.

Evidence of increased chromosomal abnormalities in French Polynesian thyroid cancer patients

PURPOSE

The aim of this study was to evaluate the frequency of chromosomal abnormalities in thyroid cancer patients before and after radioactive iodine administration in order to assess cytogenetic particularity in Polynesian thyroid cancer patients.

METHODS

Chromosomal abnormalities were studied in 30 Polynesian patients with differentiated thyroid cancer, prior to and 4 days after 131I administration. Unstable chromosomal abnormalities were counted in peripheral blood lymphocytes using a conventional cytogenetic method. Peripheral blood was irradiated in vitro at different doses (0.5, 1 and 2 Gy) in order to establish the dose-response of the lymphocytes. Control groups were composed of 50 European thyroid cancer patients before and after first administration of 131I, and of ten European healthy donors. In addition, in vitro irradiation assays were performed at different doses (0.5, 1 and 2 Gy).

RESULTS

The relative risk of spontaneous dicentrics before any radiation treatment was 2.9 (95% CI 1.7-5.1) times higher among Polynesian thyroid patients than among European thyroid cancer patients. After in vitro irradiation, the rise in frequency of dicentrics was similar in the Polynesian thyroid cancer group and the European thyroid patients and healthy donors. Four days after administration of 3.7 GBq 131I, the relative risk for a dicentric per cell was 1.3 (95% CI 1.0-1.5) times higher in Polynesian than in European patients. This can be explained by higher 131I retention in Polynesian compared with European patients. The results obtained revealed an increased frequency of cytogenetic abnormalities in Polynesian thyroid cancer patients compared with European control patients.

CONCLUSION

These preliminary findings are compatible with possible previous environmental aggression and therefore imply a need for further investigations on larger series including, in particular, French Polynesian healthy donors. In addition to French Polynesians, Maori and Hawaiian control groups could be useful.

Baseline and treatment-induced chromosomal abnormalities in peripheral blood lymphocytes of Hodgkin's lymphoma patients

PURPOSE

To study chromosomal abnormalities in 49 patients with Hodgkin's lymphoma (HL), before and after treatment and at several times during a 2-year period.

METHODS AND MATERIALS

Simple chromosomal aberrations (CAs) and complex chromosomal rearrangements (CCRs) were counted in peripheral lymphocytes by painting of chromosomes 1, 3, and 4 (fluorescence in situ hybridization). A control population was composed of 20 healthy donors and 69 untreated cancer patients who had undergone various radiologic scans.

RESULTS

A greater frequency (p < 10(-4)) of spontaneous cytogenetic abnormalities was observed in untreated HL patients compared with the control populations. CCRs were observed exclusively in the HL population (p < 10(-4)). Chemotherapy was associated with a significant increase in the frequency of CAs (p < 10(-4)), according to the chemotherapy regimen (p = 0.002). Immediately after radiotherapy, a significant increase (p < 10(-4)) was observed in CAs according to the size of the irradiation field. Conversely, the significant increases in the frequency of CCRs observed after treatment did not correlate with the chemotherapy regimens, radiotherapy dose, or size of the irradiation field. The evolution of CAs vs. CCRs over time was also dissociated: during the follow-up of these patients, a significant decrease was observed in the frequency of CAs at 6 months and 1 and 2 years. In contrast, after an initial decrease for up to 6 months after treatment, the frequency of CCRs remained constant for up to 2 years.

CONCLUSION

Increased cytogenetic abnormalities were observed in untreated HL patients compared with the control populations. The greater frequency of cytogenetic abnormalities persisted in some patients. The presence of CCRs supports the concept of a unique genetic environment in HL patients that persists in response to potentially noxious treatments.

Multiple molecular mechanisms contribute to radiation sensitivity in mantle cell lymphoma

Mantle cell lymphomas (MCL) are characterized by their aggressive behavior and poor response to chemotherapy regimens. We report here evidence of increased in vitro radiation sensitivity in two cell lines that we have generated from two MCL patients (UPN1 and UPN2). However, despite their increased radiation sensitivity, UPN2 cells were totally resistant to apoptotic cell death, whereas UPN1 cells underwent massive apoptosis 6 h after irradiation. The frequency of induced chromosomal abnormalities was higher in UPN1 as compared to UPN2. Distinct mechanisms have been found to contribute to this phenotype: a major telomere shortening (UPN1 and UPN2), deletion of one ATM allele and a point mutation in the remaining allele in UPN2, mutation of p53 gene (UPN1 and UPN2) with absence of functional p53 as revealed by functional yeast assays. After irradiation, Ku70 levels in UPN1 increased and decreased in UPN2, whereas in the same conditions, DNA-PKcs protein levels decreased in UPN1 and remained unchanged in UPN2. Thus, irradiation-induced apoptotic cell death can occur despite the nonfunctional status of p53 (UPN1), suggesting activation of a unique pathway in MCL cells for the induction of this event. Overall, our study demonstrates that MCL cells show increased radiation sensitivity, which can be the result of distinct molecular events. These findings could clinically be exploited to increase the dismal response rates of MCL patients to the current chemotherapy regimens.

Blastoid mantle cell lymphoma: evidence for nonrandom cytogenetic abnormalities additional to t(11;14) and generation of a mouse model

Mantle cell lymphoma (MCL) is characterized by the t(11;14)(q13;q32), which is associated with cyclin D1 hyperexpression and a poor prognosis. MCL cases have been shown to progress to a more aggressive disease but the molecular events responsible of this phenomenon have not been determined. We have established two cell lines from the pleural effusions of two patients with MCL that we have used for further cytogenetic characterization to better define the incidence and nature of secondary chromosome abnormalities using multicolor fluorescence in situ hybridization, whole chromosome paint, and specific probes. Both cell lines grew independently without growth factors. Using CCND1/IGH-specific probes, patient UPN1 was found to have a masked t(11;14). Numerous and complex chromosomal abnormalities were found in both cell lines affecting chromosomes 2, 8, 13, 18, 22, X, and Y. These abnormalities included 8p losses, suggesting the presence of an anti-oncogene in this region, rearrangements of 8q24, MYC gene, and translocations involving 8, X, and Y chromosomes, which might be significant in the pathogenesis of MCL progression. The use of the cell lines (UPN1) allowed us to generate a mouse model of human MCL, mimicking a disseminated lymphoma and leading to the death of the animals in 4 weeks. This blastoid MCL model could be of major interest to determine molecular events involved in MCL progression, allowing isolation of involved genes and their functional characterization, and to study the effects of new chemotherapy regimens in mouse models.

Premature chromosome condensation associated with fluorescence in situ hybridisation detects cytogenetic abnormalities after a CT scan: evaluaton of the low-dose effect

The purpose of this study was to assess the cytogenetic effects of the X ray irradiation used during a CT scan in order to estimate the mean absorbed dose in circulating lymphocytes. Chromosomal aberrations were scored in blood lymphocytes of ten patients undergoing CT scans, by applying fluorescence in situ hybridisation (FISH) to metaphase cells and premature chromosome condensation (PCC) with chromosomes 1, 3 and 4 painting probes immediately after exposure. This generated a dosimetric index that reflects the dose to the circulating lymphocytes. By using PCC a significant increase in the frequency of chromosomal fragment was observed immediately after a CT scan. However, no significant increase in chromosomal aberration was detected in metaphase cells. The mean dosimetric index immediately after exposure was 0.057 Gy (95% CI: 0.052-0.082 Gy). This dosimetric index depends essentially on the size of the examined and exposed blood volumes. This dose is in close agreement with the dose length product (DLP) (Gy cm) (R = 0.80). It should be kept in mind when justifying requests for diagnostic CT scan especially in young patients. The presence of chromosomal fragments after a CT scan indicated the cytogenetic effect of a low dose. PCC associated with chromosome painting is a method for detecting the cytogenetic effect of a low dose immediately after exposure.

Expression of tyrosine hydroxylase and vasopressin in magnocellular neurons of salt-loaded aged rats

Tyrosine hydroxylase (TH) is expressed in catecholaminergic neurons. However, under certain conditions it is also ectopically expressed in magnocellular neurons of the hypothalamus. To test the hypothesis that this expression of TH is related to the cellular activation of these neurons and/or to the vasopressin (VP) expression, we studied the expression of both TH and VP in control and salt-loaded aged rats. Our results demonstrate that aged rats show a marked TH expression in VP cells which is further increased by osmotic stimulation in the absence of increase in VP synthesis in the supraoptic nucleus. The presence of TH-immunopositive dendritic swellings in the ventral part of this nucleus reveals the high state of plasticity of these neurons. Furthermore, the lack of several actors of catecholamine biosynthesis in these neurons suggests a different role for TH. This study further demonstrates an ectopic expression of TH in hypothalamic neurons of aged rats and a TH expression linked to the activation of VP neurons but unrelated to VP synthesis.

Specific features of chronic astrocyte gliosis after experimental central nervous system (CNS) xenografting and in Wobbler neurological mutant CNS

This study sets out to compare and contrast the astrocyte reaction in two unrelated experimental designs both resulting in marked chronic astrogliosis and natural motoneuron death in the wobbler mutant mouse and brain damage in the context of transplantation of xenogeneic embryonic CNS tissue into the striatum of newborn mice. The combined use of GFAP-labeling and confocal imaging allows the morphological comparison between these two different types of astrogliosis. Our findings demonstrate that, in mice, after tissue transplantation in the striatum, gliosis is not restricted to the regions of damage: it occurs not only near the site of transplantation, the striatum, but also in more distant regions of the CNS and particularly in the spinal cord. In the wobbler mutant mouse, a strong gliosis is observed in the spinal cord, site of motoneuronal cell loss. However, moderate astrocytic reaction (increased GFAP-immunoreactivity) can also be found in other wobbler CNS regions, remote from the spinal cord. In the wobbler ventral horn, where neurons degenerate, the hypertrophied reactive astrocytes exhibit a dramatic increase of glial fibrils and surround the motoneuron cell bodies, occupying most of the motoneuron environment. The striking and specific presence of hypertrophic astrocytes in wobbler mice accompanied by a dramatic increase of glial fibrils located in the vicinity of motoneuron cell bodies suggests that short astrogliosis fills the space left by degenerating motoneurons and interferes with their survival. In the spinal cord of xenografted mice, chronic astrogliosis is also observed, but only glial processes without hypertrophied cell bodies are found in the neuronal micro-environment. It is tempting to speculate that gliosis in the wobbler spinal cord, the local accumulation of astrocyte cell bodies, and high density of astrocytic processes may interfere with the diffusion of neuroactive substances in gliotic tissue, some of which are neurotoxic, and cooperate or even trigger neuronal death.

Dental device-associated problems: an analysis of FDA postmarket surveillance data

BACKGROUND

The authors provide an analysis of dental device adverse event reports collected through the U.S. Food and Drug Administration's, or FDA's, mandatory and voluntary reporting programs between Aug. 1, 1996, and June 30, 1999.

METHODS

This study includes an analysis of the total number of dental device adverse events reported during the study period and uses descriptive statistics to depict reporters' occupations, types of adverse events (deaths, injuries, malfunctions), device categories, device problems and patient problems.

RESULTS

A total of 272,241 device reports were received during the 35-month study period, 28,555 (10.5 percent) of which involved dental devices. Within these reports, two deaths (0.007 percent), 18,406 injuries (64.4 percent) and 9,942 device malfunctions (34.8 percent) were reported. The most commonly reported dental devices were endosseous implants, which represented more than 90 percent of all dental device reports. Most reports (84.1 percent) provided the reporter's occupation, and the most frequently cited occupation was dentist (76.3 percent), followed by dental assistant (4.2 percent).

CONCLUSIONS

Dentists and dental staff members are a vital link in the FDA's adverse event reporting system and are encouraged to report device problems to the FDA MedWatch program.

[Validation of biological dosimetry in patients conditioned with total body irradiation: conventional cytogenetics and in situ hybridization(FISH)]

PURPOSE

Validation of biological dosimetry versus physical dosimetry in malignant haemopathy patients conditioned by total body irradiation (TBI) before bone marrow transplantation (BMT).

PATIENTS AND METHODS

The scoring of chromosomal aberrations in peripheral lymphocytes irradiated in vivo was used to perform the biological dosimetry. The data were compared to those obtained with healthy volunteers' total blood exposed to in vitro irradiation with linear accelerator doses (0.2, 0.5, 0.75, 1, 2, 3, 4 and 5 Gy) for dose-response curves. In experimental animal models, can in vivo and in vitro responses be considered as being the same? All the published human data are based on retrospective dose evaluation with very large uncertainties on the dose precisely delivered to the subject. TBI before BMT was taken as a model where the dose calculation results from the physical method, with homogeneous beam and dose delivered precisely along the entire organism. In vivo response allows us to validate biological dosimetry in 15 adult patients (female + male), before (D = 0 Gy) and after the first fraction of 1.8 Gy, delivered by a linear accelerator (18 MV, dose-rate of 15.8 cGy/min-1). Two methods, conventional cytogenetics (CCG) and fluorescent in situ hybridization (FISH painting) of chromosome 4 were respectively used to analyze the unstable chromosome aberrations and stable chromosome aberrations.

RESULTS

Healthy volunteer lymphocytes, before irradiation, yielded 0.1% dicentrics and 0.3% translocations of chromosome 4, with 2.5% for the whole genome. Patients before irradiation had 2% dicentrics and 11.48% chromosome 4 translocations for the whole genome. In the 15 patients, for a physical dose of 1.8 Gy, the evaluated biological dose was 1.93 Gy (95% CI: 1.85-2.05 Gy) with conventional cytogenetics and 2.06 Gy (95% CI: 1.75-2.15 Gy) with FISH.

CONCLUSION

These results, in which the biologically estimated dose is in complete agreement with the dose calculated by physical dosimetry in the homogeneous irradiation model, suggest the validation of biological dosimetry in TBI conditioning.

Biological dosimetry after total body irradiation (TBI) for hematologic malignancy patients

PURPOSE

Biological dosimetry based on scoring chromosomal aberrations in peripheral lymphocytes was compared to physical dosimetry done for total body irradiation (TBI) before bone marrow transplantation (BMT) in patients with hematologic malignancies.

PATIENTS AND METHODS

Fifteen patients undergoing TBI were included in the study. A total dose of 12 Gy in 2.5 days was fractionated into 2 or 3 daily doses of 1.8 Gy delivered by a 18 MV linear accelerator (dose rate: 15.8 cGy x min(-1)). Blood samples were obtained from patients before irradiation and after the first fraction of 1.8 Gy. A standard dose-effect curve was established by in vitro irradiation of healthy volunteer lymphocytes. Chromosomal aberrations were scored by the conventional cytogenetics (CCG) method for unstable anomalies and by fluorescent in situ hybridization (FISH) for stable anomalies.

RESULTS

Healthy donor lymphocytes before irradiation yielded 0.1% dicentrics and 0.3% translocations of chromosome 4 (Chr. 4), that is 2.5% for the whole genome. Patients before irradiation had 2% of dicentrics and 1.1% of chromosome 4 translocations. The biologically estimated dose of the 15 patients after exposure to 1.8 Gy was 1.93 Gy (95% CI: 1.85-2.05) according to CCG, and 2.06 Gy (95% CI: 1.75-2.15) by FISH.

CONCLUSION

The dose estimated by biological dosimetry, in this case of homogeneously distributed radiation of TBI agrees well with the absorbed radiation dose calculated by physical dosimetry.

Simultaneous measurement of reactive oxygen species and reduced glutathione using capillary electrophoresis and laser-induced fluorescence detection in cultured cell lines

A capillary zone electrophoretic (CZE) method coupled with laser-induced fluorescence (LIF) was developed for the simultaneous determination of two important intracellular parameters related to oxidative stress (i.e. reactive oxygen species, ROS, and reduced glutathione, GSH). This rapid and sensitive method was applied to the study of oxidative stress in cultured V79 fibroblast cells. The fluorogenic reagents selected were: (i) dihydrorhodamine-123 (DHR-123) which is converted intracellularly by ROS to the fluorescent rhodamine-123 dye (Rh-123), and (ii) naphthalene-2,3-dicarboxaldehyde (NDA), which reacts quickly with GSH in cell extracts to produce a fluorescent adduct. Separation of Rh-123, GSH-NDA and gamma-glutamylcysteine-NDA adducts was performed using an uncoated fused-silica capillary and a 100 mM borate buffer, pH 9.2, at 20 degrees C and at an applied voltage of 25 kV; LIF detection was operated using an argon laser. The cell line was also tested for its ability to alleviate oxidative stress induced by tert-butylhydroperoxide (t-BuOOH). Exposure to t-BuOOH (up to 3 mm for 2 h) did not affect the intracellular ROS and GSH concentrations. At higher (4-10 mM) t-BuOOH concentrations, an inverse relationship between the concentrations of ROS and GSH was obtained, showing that the present method can readily evaluate the gradual consumption of the primary cellular scavenger of ROS which occurs simultaneously with the increase of oxidative insult.

Radiosensitivity of human normal and tumoral thyroid cells using fluorescence in situ hybridization and clonogenic survival assay

PURPOSE

By using cell survival as a reference, we evaluated the radiosensitivity of human normal and tumoral thyroid cells using of radiation-induced translocations.

METHODS AND MATERIALS

Tissue samples were obtained from patients undergoing thyroidectomy. Cell cultures were established, irradiated with 60Co, and metaphases painted using commercial whole-chromosome 4 hybridization probe and pancentromeric probe. The clonogenic survival was assessed by conventional colony forming assay.

RESULTS

After irradiation, normal cultured thyroid cells yielded a higher number of translocations than cultures derived from adenomas or thyroid carcinoma. The colony forming assay demonstrated, by way of the mean inactivation dose, a higher survival of thyroid carcinoma and adenoma cells than of normal thyroid cells. This difference between tumoral and nontumoral cells is significant in each method (p = 0.0001), and cannot be explained by apoptosis in irradiated malignant cells. Correlation of the results obtained by both methods is shown by comparing the survival fraction at 2 Gy (SF2) and the percentage of chromosome 4 translocations at 2 Gy.

CONCLUSION

These results indicate that the yield of radiation-induced translocations serves as a good and rapid prediction of the intrinsic radiosensitivity of thyroid cells, and that this test could be applied to other tumors.

Determination of cellular thiols and glutathione-related enzyme activities: versatility of high-performance liquid chromatography-spectrofluorimetric detection

A high-performance liquid chromatography (HPLC) method to determine the most important cellular thiols [reduced glutathione (GSH), cysteine, gamma-glutamylcysteine and cysteinylglycine] is described. Separation relies upon isocratic ion-pairing reversed-phase chromatography and detection is operated by spectrofluorimetry coupled with post-column derivatization reactions using either N-(1-pyrenyl)maleimide (NPM) or ortho-phthalaldehyde (OPA). When OPA is used without co-reagent, only GSH and gamma-glutamylcysteine are detected (heterobifunctional reaction). However, either the OPA reaction in the presence of glycine in the mobile phase (thiol-selective reaction) or NPM allows the detection of all the cited thiols. The HPLC system has been validated as concerning linearity, accuracy and precision. The low detection limits reached (in the pmol range for each thiol injected) allow the screening and the quantification of thiols (as NPM derivatives) in V79cl and V79HGGT cells as well as the measurement of two cytosolic enzymes related to the glutathione synthesis, using the heterobifunctional OPA reaction.

gamma-Glutamyltransferase dependent generation of reactive oxygen species from a glutathione/transferrin system

In the presence of molecular oxygen and iron or copper ions, a number of antioxidants paradoxically generate reactive oxygen species (ROS) leading to free radical damage of nucleic acids and oxidative modification of lipids and proteins. The present work demonstrates that the combination of three components, which are often considered as part of an antioxidant protection system, can generate ROS. Purified human gamma-glutamyltransferase (GGT) in the presence of 2 mM glutathione (GSH) and 80 microM transferrin, as an iron source, at pH 7.4 generates ROS, as measured by chemiluminescence of luminol. Initiated by the addition of purified GGT, generation of ROS reached a maximal rate in the first 6 min. Intensity of the chemiluminescence was only slightly enhanced by addition of 200 microM hydrogen peroxide. Generation of ROS was also investigated in transfected V79 cells expressing human GGT. In comparison with GGT negative V79 cells, only recombinant cells expressing a high level of GGT on the cell membrane were able to generate ROS. Generation of ROS in these cells reached a maximum within 2 min and was enhanced by 200 microM hydrogen peroxide. We further confirmed the hypothesis that cysteinylglycine (CysGly), a product of GGT/GSH reaction, identified by high-performance liquid chromatography, but not GSH, was responsible for ROS formation initiated by the reductive release of iron from transferrin. These data clearly indicate that under physiological conditions, GGT is directly involved in ROS generation.

Combination of radioiodine (131I) and probe-guided surgery for persistent or recurrent thyroid carcinoma

To improve the completeness of surgical excision of persistent or recurrent differentiated thyroid carcinoma, the following protocol was used for the treatment of 54 patients with functioning lymph node metastases: administration of 3.7 gigabecquerels (100 mCi) 131I; total body scintigraphy (TBS) on day 4; surgery on day 5, using an intraoperative probe (Gammed 2, Eurorad); and postoperative TBS with the remaining 131I activity on day 7. The 54 patients (35 women and 19 men presenting 47 papillary carcinomas, 2 well differentiated follicular carcinomas, and 5 poorly differentiated follicular carcinomas) had already undergone surgery for differentiated thyroid carcinoma: total thyroidectomy (51 patients) or lobectomy with isthmusectomy (3 patients), with lymph node dissection in 33. One to 7 131I treatments were performed before inclusion. Preoperative 131I-TBS with a high dose of 131I allowed accurate localization of previously suspected neoplastic foci and detection of yet unknown foci in 56%; it was the most sensitive tool for localizing neoplastic foci. The use of an intraoperative probe was considered decisive in 20 patients, as neoplastic foci were found inside sclerosis due to previous surgery (n = 9), at unusual sites behind vessels or in the mediastinum (n = 10), or both (n = 1). In 26 patients, it facilitated the preoperative detection of foci with 131I uptake already depicted at preoperative 131I-TBS. In all 46 patients, the completeness of excision was demonstrated by both the probe and the postoperative 131I-TBS and was confirmed during follow-up. Of note, lymph node metastases undetected by 131I-TBS or by the probe were found in 14 patients at histological examination. This clearly shows that en block dissection is the only recommended procedure. In four patients, no neoplastic foci were found and in four patients, uptake was either due to the thymus (in two) or to the salivary glands (in two).

Microcarcinoma of the thyroid gland: the Gustave-Roussy Institute experience

BACKGROUND

Patients with thyroid microcarcinoma (TMC) have favorable long term prognoses. However, recurrences in the neck and distant metastases have been reported. The authors investigated independent factors associated with recurrence in an effort to define therapeutic guidelines.

METHODS

Two hundred eighty-one patients (207 females, 74 males; mean age, 41.9 years) with a differentiated thyroid carcinoma < or = 1 cm in greatest dimension (mean size +/- standard deviation, 5.9+/-3.3 mm) were analyzed. The median follow-up time was 7.3 years.

RESULTS

TMC diagnosis was incidental in 189 patients, and metastases were the first manifestation of the disease in the other 92 patients. Therapy included near-total thyroidectomy for 195 patients, lymph node dissection for 195, and therapeutic administration of radioiodine for 124. Eleven recurrences (3.9%) were observed 4.3+/-2.7 years (mean +/- standard deviation) after initial treatment: all had locoregional recurrence (4 in the thyroid bed and 7 in the lymph nodes), and in one of these the local recurrence was associated with lung metastases. Multivariate analysis showed that two parameters significantly influenced TMC recurrence, namely, the number of histologic foci (P < 0.002) and the extent of initial thyroid surgery (P < 0.01). Only 3.3% of patients with unifocal TMC treated with loboisthmusectomy had tumor recurrence.

CONCLUSIONS

The recurrence rate for TMC appears to be low (3.9%). In the authors' view, loboisthmusectomy is the treatment of choice for patients with TMC when only one focus of cancer is found histologically, and total thyroidectomy is the optimal treatment for patients with multiple foci.

Biologic dosimetry in thyroid cancer patients after repeated treatments with iodine-131

To estimate a cumulative dosimetric index that reflects the dose to the circulating lymphocytes after repeated treatments with 131I, biologic dosimetry was applied to 18 patients with differentiated thyroid carcinoma and neck relapse or lung metastases.

METHODS

Chromosomal aberrations were scored in peripheral blood samples that were obtained before and 4 days after each administration of 3.7 GBq 131I according to two methods, conventional cytogenetics and chromosome 4 painting.

RESULTS

The mean dosimetric index was equal to 0.5 Gy by both methods after the administration of 3.7 GBq 131I. Repeated administrations of 131I delivered the same dose each time, resulting in a cumulative dose from 1-3.5 Gy in the patients who had two to seven treatments. However, the estimated dose, based on the number of chromosomal aberrations on Day 4 and, above all, from the third treatment on, was considerably lower than the real dose absorbed by the lymphocytes. This may be linked to the phenomenon of apoptosis, which results in a loss of information during the course of repeated irradiation.

CONCLUSION

Both chromosomal painting and conventional cytogenetics underestimate the cumulative dose after repeated 131I treatments. A complementary test measuring apoptosis may improve the dose estimates.

Digital superimposition of CT and positive SPECT tumor images. Phantom study and clinical applications

Digital superimposition of SPECT and CT data was evaluated in a phantom and then applied to patient data. Seven patients were studied. Six patients had pheochromocytomas as evidenced by I-131 or I-123 MIBG localization and one had ovarian cancer imaged by In-111 OC125 MoAb. Anatomic or skin landmarks identified the level of each SPECT transaxial slice. Both SPECT and CT image data sets were transferred to a minicomputer connected to an image processor. Afterwards, a scaled, rotated and translated realignment was performed. Data for each modality were coded in different primary colors and then superimposed. Superimposition of phantom data was checked for the absence of distortion of pinpoint and large structures. For suspected tumor sites, superimposition of the patients' slices were allowed to check for matching SPECT and CT abnormalities to localize a SPECT abnormality without a corresponding CT lesion or to distinguish SPECT abnormalities from those seen on CT. In one case, the technique failed because of very low I-131 MIBG-tumor uptake. The superimposition decreases false positives in SPECT and both false negatives or false positives in CT.

Sequential biological dosimetry after a single treatment with iodine-131 for differentiated thyroid carcinoma

To determine the cytogenetic and genotoxic risk associated with therapeutic exposure to 131I (3.7 GBq) in 50 patients with differentiated thyroid carcinoma, we estimated the dosimetric index that reflects the dose to the circulating lymphocytes on Day 4 and at several time intervals after exposure over a period of 2 yr.

METHODS

Chromosomal aberrations were scored in peripheral lymphocytes obtained before and then 4 days, 3 mo, 6 mo, 1 yr and 2 yr after the first administration of 3.7 GBq 131I according to two methods: conventional cytogenetics and chromosome 4 painting.

RESULTS

The dosimetric index was 0.52 Gy on Day 4, 0.49 Gy at 3 mo, 0.45 Gy at 6 mo, 0.44 Gy at 1 yr and 0.42 Gy at 2 yr by conventional cytogenetics and 0.47 Gy on Day 4, 0.45 Gy at 3 mo, 0.44 Gy at 6 mo, 0.43 Gy at 1 yr and 0.42 Gy at 2 yr by chromosome 4 painting. We found a decrease in the frequency of chromosomal aberrations between Day 4 and 3 mo after exposure. This may be due to the decrease of lymphocyte counts shortly after 131I administration, which will recover later on. In contrast, the number of anomalies remained constant starting 3 mo after 131I administration.

CONCLUSION

These techniques permit retrospective biological dosimetry for up to 2 yr after therapeutic exposure to 131I.

Leukaemias and cancers following iodine-131 administration for thyroid cancer

We studied 1771 patients treated for a thyroid cancer in two institutions. None of these patients had been treated with external radiotherapy and 1497 had received (131)I. The average (131)I cumulative activity administered was 7.2 GBq, and the estimated average dose was 0.34 Sv to the bone marrow and 0.80 Sv to the whole body. After a mean follow-up of 10 years, no case of leukaemia was observed, compared with 2.5 expected according to the coefficients derived from Japanese atomic bomb survivors (P = 0.1). A total of 80 patients developed a solid second malignant neoplasm (SMN), among whom 13 developed a colorectal cancer. The risk of colorectal cancer was found to be related to the total activity of (131)I administered 5 years or more before its diagnosis (excess relative risk = 0.5 per GBq, P = 0.02). These findings were probably caused by the accumulation of (131)I in the colon lumen. Hence, in the absence of laxative treatment, the dose to the colon as a result of (131)I administered for the treatment of thyroid cancer could be higher than expected from calculation of the International Commission on Radiological Protection (ICRP). When digestive tract cancers were excluded, the overall excess relative risk of second cancer per estimated effective sievert received to the whole body was -0.2 (P = 0.6).

Characterization and radiosensitivity at high or low dose rate of four cell lines derived from human thyroid tumors

PURPOSE

This study attempted to establish cell lines derived from human differentiated thyroid tumors, and to characterize and evaluate the radiation dose-rate effect.

METHODS AND MATERIALS

Two cell lines (K1 and K2) were derived from papillary carcinomas, one (K7) from a follicular less-differentiated carcinoma and one (A14) from a follicular adenoma. Cell-survival curves after irradiation were established by the in vitro colony method. Radiation doses were delivered either at a high (45.9 Gy/h) or low dose rate (0.6 Gy/h) by a 60Co source. The data were analyzed according to the linear quadratic and multitarget model of radiation action.

RESULTS

Doubling times were around 24 h. All cell lines were positive for intracellular thyroglobulin. Cyclic adenosine monophosphate (cAMP) response to thyrotropin (TSH) was significant for the cell lines derived from the follicular adenoma and follicular carcinoma. The two cell lines derived from papillary carcinomas were tumorigenic after inoculation into nude mice. After high-dose-rate irradiation, the surviving fraction at 2 Gy (SF2) was not significantly different for the three malignant cell lines K1, K2, and K7, and ranged from 0.39 to 0.42. For the adenoma cell line A14, we found a higher radiosensitivity with a lower SF2 value and a higher alpha parameter. After low-dose-rate irradiation, only one cell line (K2) showed a significant low-dose-rate sparing with a dose reduction factor of 1.35.

CONCLUSION

The major result of our study is the weak effect of the dose rate on the survival of thyroid cell lines.

Biological dosimetry in patients treated with iodine-131 for differentiated thyroid carcinoma

Biological dosimetry was applied to 30 patients with differentiated thyroid carcinoma who were treated with 131I (3.7 GBq) to ablate thyroid remnants after surgery or in case of metastases.

METHODS

Chromosomal aberrations were scored in peripheral blood samples obtained before and 4 days after the first administration of 3.7 GBq 131I according to two methods: conventional cytogenetics and chromosome 4 painting. This generated a dosimetric index that reflects the dose to the bone marrow.

RESULTS

Results of both techniques were in close agreement. The mean dosimetric index at Day 4 was 0.54 Gy (95% CI: 0.45-0.62 Gy) by conventional cytogenetics and 0.48 Gy (95% CI: 0.42-0.61 Gy) by chromosome 4 painting. This dose is 2-4 times higher than that derived from the MIRD estimates. Since blood was drawn at Day 4, this technique underestimates the dose by at least a third. The high dose estimate may be related to the hypothyroid status of these patients at the time of 131I administration, a condition which decreases renal clearance of 131I and thus increases whole-body irradiation. This dose estimate was closely related to whole-body retention of 131I at Day 4.

CONCLUSION

These data should be used to estimate the risk due to 131I exposure.