Rectal cancer surgery : what's in a name?

The field of rectal cancer treatment is a dynamic and changing field, due to better understanding of the pathology and new medical treatment options, but perhaps mostly due to innovations in the surgical approach. Surgery is the cornerstone for rectal cancer treatment. Currently, Total Mesorectal Excision is the gold standard. After evolution towards laparoscopic TME, improving technology has led to the development of platforms that allow transanal TME and robotic TME. In addition, local excision can be performed safer and more accurately by means of Transanal Endoscopic Microsurgery (TEM), TransAnal Minimally Invasive Surgery or Endoscopic Submucosal Dissection (ESD), possibly avoiding TME. The aim of this review is to summarize the different surgical techniques and approaches for rectal cancer in function of tumor stage and describe the specifics of the technique.

Large deletions play a minor but essential role in congenital coagulation factor VII and X deficiencies

Congenital factor VII (FVII) and factor X (FX) deficiencies belong to the group of rare bleeding disorders which may occur in separate or combined forms since both the F7 and F10 genes are located in close proximity on the distal long arm of chromosome 13 (13q34). We here present data of 192 consecutive index cases with FVII and/or FX deficiency. 10 novel and 53 recurrent sequence alterations were identified in the F7 gene and 5 novel as well as 11 recurrent in the F10 gene including one homozygous 4.35 kb deletion within F7 (c.64+430_131–6delins - TCGTAA) and three large heterozygous deletions involving both the F7 and F10 genes. One of the latter proved to be cytogenetically visible as a chromosome 13q34 deletion and associated with agenesis of the corpus callosum and psychomotor retardation.

Conclusions

Large deletions play a minor but essential role in the mutational spectrum of the F7 and F10 genes. Copy number analyses (e. g. MLPA) should be considered if sequencing cannot clarify the underlying reason of an observed coagulopathy. Of note, in cases of combined FVII/FX deficiency, a deletion of the two contiguous genes might be part of a larger chromosomal rearrangement.

Oncological supportive-care unit (OSU): An effective toxicity management model

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Background: Oncological patients (pts) frequently experience treatment-related toxicities worsening outcome. According to literature data, 23% - 50% emergency department (ED) and/or hospital admissions in this setting could be avoidable and hesitate in higher management costs and worse quality of life (QoL). Cancer treatment adherence rate is 27% - 87%, mostly related to chemotherapy and post-surgical side effects. Since May 2014 we established an OSU to improve clinical outcome and treatment adherence, to reduce ED access/hospital admissions and toxicities management costs. Methods: All OSU data have been recorded in a database which includes daily management costs into an Italian regional regimen called MAC (Complex Ambulatory Macro-activities). ED accesses were recorded by our “First aid ED operative system”. Hospitalizations costs were evaluated according to regional DRG (Diagnosis Related Group) value and Hospital Discharge Register (HDR). All pts admitted to OSU should answer to two validated questionnaires regarding QoL and anxiety: FACT-G (General FunctionalAssessment Cancer Therapy) and HADS (Hospital Anxiety and depression Scale). We compared toxicities management costs 20 months before and 20 months during OSU. Results: From May 2014 to December 2015, 302/719 pts were admitted to OSU for a supportive care therapy. We obtained the reduction of the costs of the ED access/hospital admission to 52%, while the gain in management was 59% (see table). PS ECOG improved in 9 (18%) pts while it was unchanged in 41 (82%) pts. Adherence to oncologic treatment was satisfactory (95%) and the average values of total FACT and HADS in the follow-up phase improved compared to baseline in 63% and 43% of pts respectively. Conclusions: The interim analysis suggests that OSU improves clinical outcome in terms of QoL and treatment adherence. Moreover, our OSU model demonstrated the possibility to reduce toxicity-related ED accesses/hospital admissions and management costs. [Table: see text]

Role of nutrition in incidence and management of cancer therapy-induced diarrhea (CTID): HEAT (Health Eat and Toxicity) prospective interventional study and preliminary data

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Background: Metastatic colorectal cancer (mCRC) patients (pts) are at high risk of CTID influencing treatment outcome. The primary end-point of our study was the decrease of grade 3-4 (G3-4 from Common Terminology Criteria for Adverse Events 4.0) CTID incidence to 50% in respect to literature data. A predefined nutritional regimen was planned and administrated to each pts. In explorative analyses, we investigated the correlation between Vitamin D deficiency and CTID incidence and between dihydropyrimidine dehydrogenase (DpD) mutations and CTID. Methods: All mCRC pts undergoing chemotherapy (CT) with an expected G3-4 CTID incidence of about 17% were enrolled. During CT the nutritionist administered a predefined, slag free diet according to Italian Society of Human Nutrition indications and within World Cancer Research Found recommendations. Results: Fifty consecutive pts were enrolled within 11 months. Pts characteristics are summarized in the table. A significant decrease (p-value 0.00096; IC 95% 0.059) of G3-4 CTID incidence to 95% was obtained in respect to literature data. No CT modification or admissions/supportive care were needed. Due to strict diet adherence (96%) > 50% pts had no diarrhea and no one had G4 diarrhea. BMI improved in 35% over-weights and in 40% obese, no changes in normal-weights. The correlation analysis showed the decrease of CTID incidence with the increase of vitamin D levels, but did not reveal a relation between DpD mutations and diarrhea. Conclusions: The preliminary results suggest a possible role of the diet on CTID prevention and a correlation with vitamin D levels. [Table: see text]

Cancer spectrum and frequency among children with Noonan, Costello, and cardio-facio-cutaneous syndromes

Background:

Somatic mutations affecting components of the Ras-MAPK pathway are a common feature of cancer, whereas germline Ras pathway mutations cause developmental disorders including Noonan, Costello, and cardio-facio-cutaneous syndromes. These ‘RASopathies' also represent cancer-prone syndromes, but the quantitative cancer risks remain unknown.

Methods:

We investigated the occurrence of childhood cancer including benign and malignant tumours of the central nervous system in a group of 735 individuals with germline mutations in Ras signalling pathway genes by matching their information with the German Childhood Cancer Registry.

Results:

We observed 12 cases of cancer in the entire RASopathy cohort vs 1.12 expected (based on German population-based incidence rates). This corresponds to a 10.5-fold increased risk of all childhood cancers combined (standardised incidence ratio (SIR)=10.5, 95% confidence interval=5.4–18.3). The specific cancers included juvenile myelomonocytic leukaemia=4; brain tumour=3; acute lymphoblastic leukaemia=2; rhabdomyosarcoma=2; and neuroblastoma=1. The childhood cancer SIR in Noonan syndrome patients was 8.1, whereas that for Costello syndrome patients was 42.4.

Conclusions:

These data comprise the first quantitative evidence documenting that the germline mutations in Ras signalling pathway genes are associated with increased risks of both childhood leukaemia and solid tumours.

Large deletions play a minor but essential role in congenital coagulation factor VII and X deficiencies

Congenital factor VII (FVII) and factor X (FX) deficiencies belong to the group of rare bleeding disorders which may occur in separate or combined forms since both the F7 and F10 genes are located in close proximity on the distal long arm of chromosome 13 (13q34). We here present data of 192 consecutive index cases with FVII and/or FX deficiency. 10 novel and 53 recurrent sequence alterations were identified in the F7 gene and 5 novel as well as 11 recurrent in the F10 gene including one homozygous 4.35 kb deletion within F7 (c.64+430_131-6delinsTCGTAA) and three large heterozygous deletions involving both the F7 and F10 genes. One of the latter proved to be cytogenetically visible as a chromosome 13q34 deletion and associated with agenesis of the corpus callosum and psychomotor retardation.

CONCLUSIONS

Large deletions play a minor but essential role in the mutational spectrum of the F7 and F10 genes. Copy number analyses (e. g. MLPA) should be considered if sequencing cannot clarify the underlying reason of an observed coagulopathy. Of note, in cases of combined FVII/FX deficiency, a deletion of the two contiguous genes might be part of a larger chromosomal rearrangement.

[The histological confirmation of diffuse axonal injury in severe brain injury survivors]

Diffuse axonal injury (DAI) plays a major role after traumatic brain injury (TBI). Its imaging is based on computed tomography (CT) or magnetic resonance imaging (MRI). However, DAI is a histological diagnosis. Histopathological findings on survival after TBI are very rare. Hence, it is unclear whether the neuroradiological findings are of clinical relevance. Cerebral specimens were taken in 24 patients with TBI requiring surgery. The presence of histopathological evidence for DAI was evaluated. Specimens were taken from an extracranial brain prolapse (n = 2) and from peripheral parts of a brain contusion (n = 22). Histological findings were correlated to the clinical course and the neurological status. A clinical follow-up was carried out 6 months after the surgery using the Glasgow Outcome Score (GOS). The study was approved by the local ethics committee. Specimens taken were temporal (n = 11), frontal (n = 8), parietal (n = 4) and cerebellar (n = 1). The incidence of DAI within these specimens was 30% (7 with DAI, 17 without DAI). DAI was verifiable up to 3 days after trauma. There was no correlation between DAI and Marshall classification in CT. The period of coma was longer in subjects with DAI. There was no difference in GOS in the case of a verified DAI. These results enforce the prognostic and neuroradiologic relevance of DAI. However, it is debatable whether the pathomorphologic findings in CT or MRI represent the histological findings of DAI. We suggest a multicentre study for further clarification.

Stenosis of a colorectal anastomosis solved by transanal endoscopic microsurgery combined with laparoscopy

OBJECTIVE

The objective of this case report is to present a minimally invasive technique for solving an anastomotic colorectal stenosis using Transanal Endoscopic Microsurgery (T.E.M.) in combination with laparoscopy.

SUMMARY

Often a re-intervention is indicated for the resolution of an anastomotic (sub-) obstruction. This re-intervention is associated with the morbidity and mortality of a laparotomy and a prolonged hospital stay. In the case here presented, a 68-year-old man underwent a laparoscopic rectosigmoid resection for a rectal adenocarcinoma. An end-to-end circular stapled colorectal anastomosis was performed. At first without any postoperative problems, the patient presented with a stenosis of the anastomosis 6 months postoperatively. This stenosis did not result in a total obstruction but was sufficiently advanced to cause faecal impaction and discomfort, which was confirmed using a retrograde gastrografine bowel study. Colonoscopic dilatations were insufficient and after several days the patient experienced a recurrence of the original stenosis. A minimally invasive re-intervention with T.E.M. was performed in combination with laparoscopy to solve the stenosis. To our knowledge, this technique has not yet been described.

CONCLUSION

In this paper we describe a possible minimally invasive technique to avoid laparotomy after colorectal or colo-anal anastomotic stenosis. Both the duration of the hospital stay and patient morbidity can be reduced in this way.

Proven germline mosaicism in a father of two children with CHARGE syndrome

CHARGE syndrome is an autosomal dominant malformation syndrome caused by mutations in the CHD7 gene. The majority of cases are sporadic and only few familial cases have been reported. In these families, mosaicism in one parent, as well as parent- to-child transmission of a CHD7 mutation, has been described. In some further cases, germline mosaicism has been suggested. Here, we report the first case in which germline mosaicism could be demonstrated in a father of two affected children with CHARGE syndrome. The truncating mutation c.7302dupA in exon 34 of the CHD7 gene was found in both affected children but was not detected in parental lymphocytes. However, in DNA extracted from the father's spermatozoa, the c.7302dupA mutation could be identified. Furthermore, mutation analysis of DNA isolated from 59 single spermatozoa revealed that the c.7302dupA mutation occurs in 16 spermatozoa, confirming germline mosaicism in the father of the affected children. This result has a high impact for genetic counselling of the family and for their recurrence risk in further pregnancies.

Anastomotic leakage of a colorectal anastomosis treated by transanal endoscopic microsurgery

OBJECTIVE

To report a minimal invasive technique for repairing an anastomotic leakage with Transanal Endoscopic Microsurgery (T.E.M.) without creating a protective ostomy.

SUMMARY

There are a large number of techniques for the management of anastomotic leakage after colorectal surgery. Depending on the size and location of the disruption, a protective ileostomy, a permanent colostomy or even reintervention for drainage or closure of the leak may be indicated. In most cases the patient faces the morbidity associated with a new intervention, a prolonged hospital stay and a future operation for closure of the stoma. In the present case a 56-year-old man underwent a laparoscopic rectosigmoid resection after two episodes of diverticulitis in six months. An end-to-end circular stapled anastomosis was constructed. Unfortunately 8-days postoperatively an anastomotic leak occurred. Attempts to close the tear non-surgically with colonoscopy and clipping failed. A minimally invasive reintervention with transanal endoscopic microsurgery (T.E.M.) was performed without creation of an ileostomy. One week postoperatively a gastrografin bowel study showed no leakage. To our knowledge, this technique has not yet been reported without the simultaneous construction of a stoma.

CONCLUSION

We describe a possible minimally invasive technique to avoid laparotomy and/or the creation of a derivative stoma in the management of anastomotic leakage. Hospital stay is not significantly prolonged, future reïntervention for closure of stoma is avoided and sphincter function is preserved.

Functional and immunophenotypic characteristics of isolated CD105(+) and fibroblast(+) stromal cells from AML: implications for their plasticity along endothelial lineage

BACKGROUND

In vitro cultures of BM cells from newly diagnosed patients with AML displayed a defective BM stromal compartment, with a reduced number of fibroblast-colony-forming unit (CFU-F: 1 +/- 1.25 SD) and a decreased proliferative ability. The purposes of our study were: 1). to select BM mesenchymal stem cells (MSC) and BM-derived stromal cells (BMDSCs) from AML patients at diagnosis and from healthy subjects, using an immunomagnetic system and either anti-CD105 or anti-fibroblast MAbs; 2). to study the immunophenotypic and functional properties of freshly isolated and cultured mesenchymal cells; 3). to test the in vitro plasticity of the selected cells to differentiate towards an endothelial phenotype.

METHODS

Fresh mononuclear cells obtained from BM of 20 patients newly diagnosed with AML and from eight healthy subjects were selected by using anti-fibroblast and anti-CD105 MAbs. Freshly isolated cells were analyzed, characterized by flow cytometry using a wide panel of MAbs and seeded in long-term culture medium to assess CFU-F formation. The level of confluence after 30 days and functional capacity in a long-term colony-forming cell culture (LTC-CFC) were tested. Furthermore, the cultured selected cell populations were assayed for their ability to differentiate into an endothelial-like cell phenotype with the addition of vascular endothelial growth factor (VEFG) and endothelial cell growth supplement (ECGS).

RESULTS

In normal subjects the selection produced an increase of the CFU-F number of 2.6-fold with anti-fibroblast MAb and 2.7-fold with the anti-CD105 MAb. Anti-fibroblast and anti-CD105 MAb selection from AML BM cells resulted in a statistically significant greater count of CFU-F that was respectively 10.6-fold (P = 0.04) and 14.4-fold (P = 0.00001) higher in comparison with the unselected AML samples. Interestingly, in 80% of AML samples immunoselection was also able to restore the capacity of the CFU-F to proliferate and form confluent stromal layers. The isolation of those layers sustained the proliferation and differentiation of hematopoietic stem cells in the LTC-CFC. The phenotypic profile of cultured BMDSCs was different from that of the freshly isolated cells, and changed in relation to the culture conditions: CD105+ selected cells cultured with VEGF and ECGS expressed endothelial markers, a finding that suggests that this cell subpopulation may have the potential to differentiate toward an endothelial-like phenotype.

DISCUSSION

We report that immunomagnetic selection represents a valid tool for the selection of BM mesenchymal cells in samples obtained from both healthy subjects and patients with AML. This technique was able to rescue two functional and immunophenotypic compartments related to two different selected populations. In particular, the CD105+ cells isolated in AML displayed, after stimulation with VEGF and ECGS, the ability to change towards an endothelial-like cell phenotype, thus revealing an unexpected plasticity. Both CD105+ and fibroblast+ cells once successfully isolated might represent sources of mesenchymal cells populations useful for in vitro investigations and, above all, as therapeutic devices.

Gene structure of human carbamylphosphate synthetase 1 and novel mutations in patients with neonatal onset

Carbamylphosphate synthetase 1 (E.C. 6.3.4.16) deficiency is a rare autosomal recessive disorder of the urea cycle that can result in severe neonatal hyperammonemia. Since the genomic structure of the CPS1 gene was not yet elucidated, mutation detection was performed by analysis of transcripts in the past. Here, we present the entire DNA sequence of the human CPS1 gene including all exon-intron boundaries. Moreover, mutation analysis was performed in six patients leading to the detection of 9 novel mutations including the missense mutations c.2528T>C and c.2623A>G, the nonsense mutations c.712C>T and c.2115ins35bp, the splice site mutations c.1263+5G>C, c.3558+1G>C and c.4101+2T>C, and a small deletion c.3036_3038delGGT. The mutations c.2528T>C and c.2623A>G were identified on a double mutated allele. New data on the genomic structure of the CPS1 gene provided in this study are useful to characterize the heterogenous molecular basis of the disease in patients deficient for carbamylphosphate 1 deficiency.

Acute colon diverticulitis in multiple myeloma patient: an unusual presentation of a colonic perforation. Case report

This case report describes an acute colonic diverticular perforation occurred to a multiple myeloma patient, taking corticosteroid and morphine therapy, revealed by a subcutaneous emphysema of upper chest and right abdomen as initial presentation. Sigmoid diverticulitis with perforation and generalized peritonitis is a severe complication of the diverticular disease and it is due to diverticular microperforation. This condition occurs more frequently in patients with widespread diverticolosis and usually after 50 years of age, and the frequency of related complications increases with age (and with the use of corticosteroids). Extraperitoneal air from the sigmoid-rectum perforation can escape diffusing superiorly though paravertebral retroperitoneal tissues and via the diaphragmatic iatus into the mediastinum, producing pneumomediastinum and it diffuses to yield superior thoracic emphysema. This report suggests that the diagnosis of retroperitoneal perforation is usually difficult because of the lack of signs of peritoneal irritation and the paucity of symptoms, particularly in patients treated with corticosteroids.

Structure of the human argininosuccinate synthetase gene and an improved system for molecular diagnostics in patients with classical and mild citrullinemia

Deficiency of argininosuccinate synthetase (ASS) causes citrullinemia, an autosomal recessive inherited defect of the urea cycle. Most patients described so far have presented with the classical form of the disease. There are also patients with a mild form of citrullinemia in whom the exact molecular basis and clinical relevance are uncertain. Mutations in the human ASS gene have not yet been described in mildly affected or asymptomatic patients with citrullinemia. The genomic sequence of the human ASS gene is not precisely known making mutation analysis difficult. Here, the entire genomic DNA sequence and mutations in the ASS gene of patients with the classical and mild form of the disease are described. The mutations c.1168G-->A (G390R) and IVS13+5 G-->A and the novel mutation c.323G-->T (R108L) have been found to be associated with classical citrullinemia, whereas the novel mutations c.535T-->G (W179R), and c.1085G-->T (G362V) have been detected on alleles of the mildly affected patients. Thus, mutations found in the human ASS gene of asymptomatic children with biochemical abnormalities and in some cases enzymatically proven citrullinemia have allowed us to classify these cases as ASS-deficient patients. The elucidation of the structure of the human ASS gene has made possible the use of intronic primers for molecular analysis of patients with mild disease and the classical form, and provides another option for prenatal diagnostics in affected families with the severe type.

Osteomyelitis pubis versus osteitis pubis: a case presentation and review of the literature

An athletic 23 year old man presented with suprapubic tenderness, fever, and raised inflammatory blood variables. A diagnostic laparoscopy was performed, with a presumed diagnosis of retrocaecal appendicitis, but no abnormalities were found, apart from free fluid in the pouch of Douglas. Imaging of the pubic area suggested bony infection and inflammation. Biopsy and culture confirmed the presence of Staphylococcus aureus, a very common pathogen. The final diagnosis was osteomyelitis pubis, an infectious disease, and osteitis pubis, an inflammatory disease.

CD34(+) cell subsets and long-term culture colony-forming cells evaluated on both autologous and normal bone marrow stroma predict long-term hematopoietic engraftment in patients undergoing autologous peripheral blood stem cell transplantation

OBJECTIVE

The aim of this study was to evaluate which CD34(+) cell subset contained in leukapheresis products could be regarded as the most predictive of long-term hematopoietic recovery after autologous peripheral blood stem cell transplantation (auto-PBSCT).

MATERIALS AND METHODS

Based on data from 34 patients with hematologic malignancies, doses of CD34(+) cells and CD34(+) cell subsets, defined by the expression of HLA-DR, CD38, CD117 (c-kit/R), CD123 (alpha subunit of IL-3/R), CD133 (AC133), and CD90 (Thy-1) antigens, were correlated with the number of short-term (i.e., colony-forming cells [CFC]) and long-term culture CFC (LTC-CFC) (generated at week 5 of culture) and with the kinetics of hematopoietic engraftment following auto-PBSCT. The capacity of autologous stroma (AS), normal human bone marrow stroma, and M2-10B4 murine cell line to sustain CD34(+) cell growth was comparatively evaluated in the LTC assay.

RESULTS

Our data demonstrated that some of the most primitive progenitor subsets (CD34(+)CD117(-)HLA-DR(-), and CD34(+)CD38(+)HLA-DR(-)) showed the strongest correlation with LTC-CFC numbers generated within the AS, whereas no significant correlation was noted using normal bone marrow stroma. Multivariate analysis showed that the only CD34 cell subset independently associated with long-term (3 to 6 months) platelet engraftment after auto-bone marrow transplantation was the CD34(+)CD117(-)HLA-DR(-) phenotype; long-term erythrocyte engraftment was correlated with CD34(+)CD38(+)HLA-DR(-) cell content. The latter further influenced platelet engraftment in the first 3 months after auto-PBSCT. The most predictive parameters for neutrophil engraftment were CD34(+)CD38(+)HLA-DR(-) cell subtype and the total LTC-CFC quantity infused.

CONCLUSIONS

These data further support the hypothesis that the type of stromal feeders influences the frequency of LTC-CFC, possibly because they differ in their ability to interact with distinct subsets of hematopoietic stem cells. Furthermore, as the use of AS in LTC assay can mimic in vitro the human bone marrow microenvironment, it can be speculated that this culture system could be a useful means to study the kinetics of recovery of bone marrow stroma following chemotherapy and PBSCT. From these results, it can be concluded that some CD34(+) cell subsets appear to be more reliable predictors of long-term hematopoietic recovery rates than total CD34(+) cell quantity.

Induction of topoisomerase II activity after ErbB2 activation is associated with a differential response to breast cancer chemotherapy

ErbB2 (HER-2) gene amplification and overexpression have been shown to predict a better outcome with doxorubicin-based chemotherapy as opposed to alkylator-based chemotherapy in early stage breast cancer. To understand the mechanism of differential response to these two regimens, we have evaluated the effect of signaling through the ErbB2 receptor on downstream enzymes that may affect drug response, using two different models. The first system employs breast cancer cells that have high levels of endogenous ErbB2 by gene amplification (BT-474 and SKBR3 cells). The second system allows us to isolate the effect of ErbB2 receptor-mediated intracellular signaling using an epidermal growth factor receptor-ErbB2 chimeric receptor activated by epidermal growth factor. Our experiments show that the cytotoxicity of doxorubicin is inhibited in ErbB2+ breast cancer cells by the anti-ErbB2 antibody, Herceptin. This is accompanied by a decrease in topoisomerase (topo) IIalpha protein and activity, suggesting that this is the mechanism of change in doxorubicin response. In addition, a 10-100-fold (1-2 log) decrease in the LD(50) of doxorubicin is seen after ErbB2 activation using the chimeric receptor model. Furthermore, we see a 100-fold decrease in the LD(50) of etoposide, another topo II inhibitor. This increase in doxorubicin sensitivity is associated with a 4.5-fold increase in the amount of topo IIalpha protein and an increase in topo II activity as measured by DNA decatenating and unknotting activities, as well as cleavable complex formation. In contradistinction to doxorubicin, we have observed an increased resistance to cyclophosphamide chemotherapy after chimeric receptor activation. We propose that the differential benefit seen with doxorubicin- versus alkylator-based chemotherapy in ErbB2+ breast cancer is due, in some cases, to ErbB2-mediated topo IIalpha activation. These data also suggest hypotheses for the optimal sequencing of Herceptin and chemotherapy agents in ErbB2+ breast cancer.

Angiogenesis in multiple myeloma: correlation between in vitro endothelial colonies growth (CFU-En) and clinical-biological features

Mouse models and studies performed on fixed bone marrow (BM) specimens obtained from patients with multiple myeloma (MM) suggest that plasma cell growth is dependent on endothelial cell (EC) proliferation within the BM microenvironment. In order to assess whether EC overgrowth in MM reflects a spontaneous in vitro angiogenesis, BM mononucleated cells from 13 untreated (UT) MM, 20 treated (11 with melphalan and nine with DAV schedule) MM, eight patients with monoclonal gammopathy of uncertain significance (MGUS) and eight controls were seeded in an unselective medium to assess EC proliferation. Furthermore, the influence of IL6 on the EC growth was investigated. Endothelial colonies (CFU-En) appeared as small clusters, formed by at least 100 slightly elongated and sometimes bi-nucleated cells expressing factor VIII, CD31 and CD105 (endoglin). The CFU-En mean number/10(6) BM mononucleated cells in untreated MM samples (2.07 s.d. +/- 1.3) was significantly higher than in normal BM (0.28 +/- 0.48), while no difference was seen between normal BM and MGUS (0.28 +/- 0.54). Interestingly, the mean number of CFU-En in the DAV group (1.88 +/- 1.6) did not differ from the UT, while it was found to be lower in the melphalan group (0.31 +/- 0.63). The addition of anti-IL6 monoclonal antibody induced a reduction of both the plasma cells in the supernatant and the CFU-En number. This study describes a rapid and feasible assay providing support for the association between EC and plasma cells further suggesting that the in vitro angiogenesis process may parallel that observed in vivo.

Stapled versus hand-sewn vascular anastomoses. An experimental study in the rabbit

OBJECTIVE

Narrowing of vascular anastomoses is a frequently encountered surgical problem, with intimal hyperplasia being one of its most important causes. The aim of the present study was to compare in a rabbit model 'manual' (hand-sewn) with 'stapled' anastomoses (using a staple device) with respect to occurrence and severity of intimal hyperplasia.

MATERIALS AND METHODS

Twenty-four male rabbits (mean weight 2,849 g) were randomly allocated to one of two groups (n = 12). An end-to-end anastomosis of the left femoral artery was performed in all animals under general anesthesia. The anastomosis was hand sewn in group 1, while a vascular closure stapler (VCS) was used in group 2. Both anastomotic time and total operation time were recorded. After 28 days, the rabbits were sacrificed. The femoral artery of operated and nonoperated sides were removed and prepared for anatomopathological examination. The I/M ratio (= difference between tunica intima and tunica media) was determined on hematoxylin-eosin stained slides. All results were analyzed using Student's t test.

RESULTS

Mean anastomotic times were 25 +/- 7 min for the 'manual' group and 17 +/- 9 min for the 'stapled' group (p = 0.02). There was no significant difference in the total operation time (55 +/- 15 vs. 41 +/- 18 min, p = 0.057). All animals survived the anastomosis procedure. In the group of 'manual' anastomosis, morbidity was significantly higher. At the moment of sacrifice, all anastomoses were patent. There was no difference in the I/M ratio between the groups.

CONCLUSIONS

The use of VCS is a promising alternative to hand-sewn anastomoses. It takes less time to perform a stapled anastomosis, the technique has a shorter learning period and morbidity seems to be lower when vascular anastomoses are applied with the VCS in this rabbit model.

Z-IQNP: a potential radioligand for SPECT imaging of muscarinic acetylcholine receptors in Alzheimer's disease

RATIONALE

The density of the M2 subtype of muscarinic acetylcholine receptors (mAChR) has been shown to be reduced in the brain of patients with Alzheimer's disease (AD). It is therefore of interest to develop a brain imaging method for diagnostic purposes. Z-(R,R)-1-azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo1-propen-3-yl)-alpha-phenylacetat e (Z-IQNP) is a muscarinic antagonist with high affinity for the M2 subtype.

OBJECTIVE

The pharmacological characteristics and topographic distribution of radiolabelled Z-IQNP as a radioligand for the M2 mAChR subtype were examined in vitro and in vivo.

METHODS

Z-IQNP was labelled with 1251 and 123I. Autoradiography was performed on whole-hemisphere cryosections from human post mortem brains. SPECT was performed in a cynomolgus monkey.

RESULTS

Autoradiography showed binding of [125I]Z-IQNP in all brain regions, which was inhibited by the non-selective muscarinic antagonist scopolamine. The addition of BIBN 99, a compound with high affinity for the M2 subtype, inhibited [125I]Z-IQNP binding particularly in the cerebellum, which has a high density of the M2 subtype. SPECT demonstrated high uptake of [123I]Z-IQNP in all brain regions. The binding was markedly reduced in all brain regions after pretreatment with the non-selective muscarinic antagonist dexetimide and also the M1 antagonist biperiden. Dexetimide markedly inhibited [123I]Z-IQNP binding in the cerebellum, which is consistent with a high density of M2-receptors in this region. The sigma receptor binding compound DuP 734 had no effect on Z-IQNP binding either in vitro or in vivo.

CONCLUSIONS

This study indicates that radiolabelled Z-IQNP has high specificity for mAChR with higher affinity for the M2 than the M1 subtype and negligible affinity for sigma recognition sites both in vitro and in vivo. [123I]Z-IQNP should be useful for future SPECT studies in AD for examination of the density of M2 receptors particularly in the cerebellum.

Lamellar bone formation in an atherosclerotic plaque of the carotid artery, with a review of histogenesis--a case report

Longer existing atherosclerotic lesions may contain calcifications; lamellar bone rarely develops within them. A 59-year-old man was referred with a progressive stroke. A high-grade stenosis of the left common carotid artery, formed by an ulcerating atherosclerotic plaque with a free-floating thrombus, was detected on angiography. An urgent endarterectomy was performed. Surprisingly this plaque contained pieces of lamellar bone, proved by histologic examination.

Chylothorax complicating left lower sleeve lobectomy

Postoperative chylothorax is an infrequent but potential life-threatening complication and has most often been described following oesophageal resection. Its incidence after pulmonary resection is low, but has increased to 0.3-0.5%, probably due to more extensive types of resections and radical lymph node dissections. We report a case of chylothorax after a left sleeve lobectomy for a primary bronchogenic carcinoma, that was treated conservatively with chest tube drainage and a diet of medium chain triglycerides. Five additional case reports in English and French literature confirmed chylothorax after bronchoplastic procedures to be extremely rare. More frequent use of bronchial sleeve resection as alternative to pneumonectomy to save functional lung tissue, can increase the incidence of chylothorax after bronchoplastic procedures.

Comparison between plain and gentamicin containing collagen sponges in infected peritoneal cavity in rats

OBJECTIVE

To study the usefulness of gentamicin-containing sponges in the infected peritoneal cavity in rats.

DESIGN

Controlled study.

MATERIAL

83 Male Wistar rats, 36 of which were treated by plain sponge, 36 by gentamicin-impregnated sponge, and 11 acted as controls.

INTERVENTIONS

A standard model of intraperitoneal infection was developed by making a 1 cm long incision in the caecum.

MAIN OUTCOME MEASURES

Postoperative mortality, macroscopic and microscopic features of infection, and bacterial concentrations in the abdomen on days 3, 6, and 9.

RESULTS

In the respective groups 2, 3 and 2 animals died during operation and 4/34 (11%), 3/33 (9%); and 0/9 died before day 3. There were appreciable reductions in the number of animals with features of infection after 3 days but these were not significant at 6 or 9 days.

CONCLUSION

Gentamicin-containing collagen sponges placed on a septic focus in the abdomen reduce local infection for at least 3 days.

Brain distortions in patients with primarily generalized tonic-clonic seizures

PURPOSE

A precondition for the diagnosis of primarily generalized epilepsy with tonic-clonic seizures (GTCS) is absence of brain pathology. This definition, based on normal findings on computed tomography (CT) and magnetic resonance imaging (MRI) is challenged however, by observation of microscopic migrational disturbances in patients with GTCS. In the present study, we examined whether hitherto undiscovered gross manifestations of the reported migrational disturbances may be detected by analysis of CT and MRI scans with a computerized anatomic brain atlas.

METHODS

The atlas program permitted group comparisons of size, intrinsic proportion, and shape of the brain. Healthy men (n = 20), patients with partial seizures (n = 8), secondarily generalized partial seizures (n = 8), and patients with GTCS (n = 10) were studied. The contours of the brain of the computerized atlas were first transformed and adjusted to the contours, central structures, and ventricles of each subject's MRI scans. During this process, the specific parameters for the shape, size, and proportion of the brain were determined, resulting in a set of values for each subject. These values were then applied for comparisons between the four investigated groups.

RESULTS

In relation to the controls, patients with GTCS had brains significantly flattened in the craniocaudal direction (p = 0.002), with a disproportionally small caudal part. The anterior portion of their brain was also, relatively elongated as compared with the posterior portion (p = 0.04). Similar systematic abnormalities were not observed in patients with partial epilepsy.

CONCLUSIONS

The observed deformations are compatible with previously reported findings of Purkinje cell degeneration and frontal lobe microdysgenesis in GTCS. The study suggests a new approach to identify effects of morphologic abnormalities in the brain when results of conventional structural neuroimaging are normal.

Tumour necrosis factor-alpha and interleukin-2 differentially affect hippocampal serotonergic neurotransmission, behavioural activity, body temperature and hypothalamic-pituitary-adrenocortical axis activity in the rat

Intraperitoneal endotoxin injection and central administration of interleukin (IL)-1beta profoundly activate hippocampal serotonergic neurotransmission. This study was designed to investigate, using in vivo microdialysis, the effects of another endotoxin-induced proinflammatory cytokine, tumour necrosis factor-alpha, and the effects of the non-inflammatory cytokine, IL-2, on hippocampal extracellular levels of serotonin. To compare the effects of these cytokines on neurotransmission with the effects on physiological parameters and behaviour, hypothalamic-pituitary-adrenocortical (HPA) axis activity, body temperature and behavioural activity were monitored as well. Time-dependent changes in serotonergic neurotransmission and HPA axis activity were determined by measuring serotonin, its metabolite 5-hydroxyindoleacetic acid and free corticosterone in dialysates. Total behavioural activity was scored by assessing the time during which rats were active. Core body temperature was measured by biotelemetry. Intracerebroventricular injection of 50 or 100 ng recombinant murine tumour necrosis factor-alpha exerted no effect on hippocampal serotonergic neurotransmission, and induced no signs of sickness behaviour. However, these doses produced a dose-dependent increase in body temperature and free corticosterone levels. In contrast, intracerebroventricular administration of 500 ng, but not of 50 ng, recombinant human IL-2 produced a marked increase in hippocampal extracellular concentrations of serotonin and 5-hydroxyindoleacetic acid, accompanied by a pronounced behavioural inhibition and other signs of sickness. Moreover, both doses of IL-2 caused a dose-dependent increase in body temperature and free corticosterone levels. Interestingly, intracerebroventricular pretreatment with the IL-1 receptor antagonist showed that the effects of IL-2 on hippocampal serotonin were completely dependent on endogenous brain IL-1. However, IL-1 seemed to play only a minor role in the IL-2-induced increase in free corticosterone. Taken together, the results show that cytokines produce partially overlapping brain-mediated responses, but are selectively effective in stimulating hippocampal serotonergic neurotransmission and inducing sickness behaviour. Moreover, we postulate that activation of hippocampal serotonin release is instrumental in the full development of behavioural inhibition.

Bromine-76 and carbon-11 labelled NNC 13-8199, metabolically stable benzodiazepine receptor agonists as radioligands for positron emission tomography

NNC 13-8241 has recently been labelled with iodine-123 and developed as a metabolically stable benzodiazepine receptor ligand for single-photon emission computed tomography (SPECT) in monkeys and man. NNC 13-8199 is a bromo-analogue of NNC 13-8241. This partial agonist binds selectively and with subnanomolar affinity to the benzodiazepine receptors. We prepared 76Br labelled NNC 13-8199 from the trimethyltin precursor by the chloramine-T method. Carbon-11 labelled NNC 13-8199 was synthesised by N-alkylation of the nitrogen of the amide group with [11C]methyl iodide. Positron emission tomography (PET) examination with the two radioligands in monkeys demonstrated a high uptake of radioactivity in the occipital, temporal and frontal cortex. In the study with [76Br]NNC 13-8199, the monkey brain uptake continued to increase until the time of displacement with flumazenil at 215 min after injection. For both radioligands the radioactivity in the cortical brain regions was markedly reduced after displacement with flumazenil. More than 98% of the radioactivity in monkey plasma represented unchanged radioligand 40 min after injection. The low degree of metabolism indicates that NNC 13-8199 is metabolically much more stable than hitherto developed PET radioligands for imaging of benzodiazepine receptors in the primate brain. [76Br]NNC 13-8199 has potential as a radioligand in human PET studies using models where a slow metabolism is an advantage.

PET study of the pre- and post-synaptic dopaminergic markers for the neurodegenerative process in Huntington's disease

PET and: markers for the pre- and postsynaptic neurons were used to study the dopamine system in vivo in Huntington's disease. The radioligands used were [11C]SCH 23390 for D1-receptors, [11C]raclopride for D2-receptors and [11C]beta-CIT for dopamine transporters. Five patients with Huntington's disease and five matched controls were recruited. Brain anatomy was examined by MRI. The findings in patients were as follows. Postsynaptic D1- and D2-receptor densities were similarly reduced in the striatum. A reduction in D1-receptor density was shown in the temporal cortex; it draws attention to the cortical degeneration in relation to the cognitive deficits observed in Huntington's disease. The reduction of D1- and D2-receptor binding potentials in the striatum correlated significantly with increasing duration of illness. The correlation between the duration of illness and decline of D1- and D2-receptors make these receptors valuable as quantitative markers for the Huntington's disease degenerative process. Besides postsynaptic changes, a significant 50% decrease of [11C]beta-CIT binding to the dopamine transporter was found in the striatum. A reduced striatal blood flow in Huntington's disease cannot be excluded and could account for a small part of the decrease in [11C]beta-CIT binding. We suggest that the finding reflects a loss of presynaptic terminals or a reduced expression of dopamine transporter in the nigrostriatal dopaminergic system in Huntington's disease.

Three-dimensional visualization and quantification of the benzodiazepine receptor population within a living human brain using PET and MRI

Positron emission tomography (PET) in combination with receptor-selective high-affinity radioligands allows the characterization of neuroreceptor distributions in the living human brain. Thus far, the visualization and quantification of receptors with PET have been limited to series of two-dimensional (2D) image planes of the anatomic receptor distribution. The development of high-resolution PET has increased the number of planes to approximately 50, supplying an excessive amount of image information from a single experiment. The inherent limitations of 2D techniques make them insufficient to apprehend and efficiently analyze this cumbersome amount of data. In the present communication we describe procedures to visualize and quantify in three dimensions (3D) the total image information from the compound set of 47 2D planes of a PET experiment using commercially available software. Three-dimensional computer graphic and volume rendering techniques were used to analyze and display the results. For the experimental application the benzodiazepine (BZ) antagonist [11C]flumazenil was used as radioligand to visualize the BZ receptor (BZR) population in the brain of a healthy human subject. Three-dimensional images of the radioligand binding receptor population were displayed with regard to volume and form in relation to the corresponding anatomic structures in the brain reconstructed from MR images. The volume-rendering technique allowed the inspection of PET signals representing BZR populations in the interior of the hemisphere as viewed from the medial projection. Thresholding and seeding techniques were used to define volumes and quantities. Using the PET data and volume rendering, the total amount of cerebral BZRs (NCerebrum) and the apparent volume they take into account (V(BZR, Cerebrum)app) could he calculated for the first time using an automated procedure. The cerebrum of the healthy subject contained 17.6 nmol of BZRs in a volume of approximately 1.25 L. The principles and application of the technical development described offer new dimensions to clinical neuroscience and should be practically useful for automated quantitative determination of neuroreceptor number in brain regions of patients with neuropsychiatric disorders and in relation to drug treatment.

Autoradiographic localisation of D3-dopamine receptors in the human brain using the selective D3-dopamine receptor agonist (+)-[3H]PD 128907

The selective D3-dopamine receptor agonist 4aR, 10bR-(+)-trans-3,4,4a, 10b-tetrahydro-4-[N-propyl-2,3-3H]-2H,5H-[1] benzopyrano[4,3-b]-1,4-oxazin-9-ol ([3H]PD 128907) was used to visualise D3-dopamine receptors in whole hemisphere cryosections from post-mortem human brain. [3H]PD 128907 has an 18- to 40-fold selectivity for D3- over D2-dopamine receptors as compared to a 7- to 24-fold selectivity of the more commonly used ligand [3H]7-OH-DPAT. [3H]PD 128907 accumulated markedly in the nucleus accumbens and in the ventral parts of caudate nucleus and putamen, with a slightly heterogeneous (patch-matrix like) distribution. The binding in the lateral parts of caudate nucleus and putamen was much less dense. No binding was obtained in any other regions. A very high proportion of [3H]PD 128907 was specifically bound, as judged from the low binding remaining in the presence of the D2/D3-dopamine receptor antagonist raclopride. This gives the ligand a potential for the detection of low density D3-dopamine receptors in the human brain. The binding obtained with [3H]PD 128907 was qualitatively similar to that using [3H]7-OH-DPAT in the presence of GTP. However, [3H]7-OH-DPAT labelled, in contrast to [3H]PD 128907, also D3-dopamine receptors in neocortex. The new compound [3H]PD 128907 appears to be a suitable radioligand for autoradiographic examination of the D3-dopamine receptor localisation in the human brain, and should also be useful for pharmacological studies of this receptor subtype.

Autoradiographic localization of extrastriatal D2-dopamine receptors in the human brain using [125I]epidepride

Epidepride is a benzamide with high affinity for central D2- and D3-dopamine receptors. The anatomical distribution of [125I]epidepride binding was examined by autoradiography, using postmortem human whole-hemisphere cryosections. The density of [125I]epidepride binding sites was high in caudate nucleus and putamen. [125I]epidepride also labeled receptors in extrastriatal region such as in the pallidum, some thalamic nuclei, the neocortex, and the substantia nigra. The neocortical binding was heterogeneously distributed. In most cortical regions, binding sites were located in superficial layers (I-II). However, in basal levels of the occipital cortex, [125I]epidepride binding was located in a deeper layer, probably corresponding to layer V. Competition studies indicated that most of the [125I]epidepride binding represented predominantly D2-dopamine receptors, in striatal as well as in extrastriatal regions. The presence of extrastriatal D2-dopamine receptor populations is of particular interest for research on schizophrenia and antipsychotic drug action.

Development of 123I-labelled NNC 13-8241 as a radioligand for SPECT visualization of benzodiazepine receptor binding

[125I]- and [123I]NNC 13-8241 were prepared from the trimethyltin precursor and radioactive iodide using the chloramine-T method. The total radiochemical yields of [125I]- and [123I]NNC 13-8241 were 60-70% and 40-50% respectively, with radiochemical purity higher than 98%. In binding studies with [125I]NNC 13-8241 in rats in vitro and in vivo a high uptake of radioactivity was demonstrated in brain regions known to have a high density of benzodiazepine (BZ) receptors such as the occipital and frontal cortex. SPECT examination with [123I]NNC 13-8241 in a Cynomolgus monkey demonstrated a high uptake of radioactivity in the occipital and frontal cortex. After displacement with flumazenil radioactivity in these brain regions was reduced to the level of a central region including the pons. Four hours after injection about 80% of the radioactivity in monkey plasma represented unchanged radioligand. This low degree of metabolism indicates that NNC 13-8241 is metabolically more stable than the radioligands hitherto developed for imaging of BZ-receptors in the primate brain.

Variability in D2-dopamine receptor density and affinity: a PET study with [11C]raclopride in man

The variability of D2-dopamine receptor binding parameters in man was determined using Positron Emission Tomography (PET) and [11C]raclopride. A saturation analysis based on five PET-experiments was performed in each of ten men and ten women. The mean density of D2-dopamine receptors (Bmax) was 28 +/- 6.9 pmol/ml (mean +/- S.D.) and the apparent affinity (Kdapp) 9.1 +/- 1.9 pmol/ml. The Hill coefficient was in all subjects close to unity (nH: 0.999 +/- 0.020), thereby indicating binding to a homogeneous class of receptors. No significant differences between males and females were found in Bmax or Kdapp. The interindividual difference in Bmax was statistically significant (alpha = 0.01). The difference in Kdapp was not significant. Upregulation of the receptor density (Bmax) has been widely discussed as a mechanism for increased dopaminergic neurotransmission in schizophrenia. This study indicates that receptor density varies considerably in a group of healthy subjects.

PET imaging of neuroreceptors in schizophrenia

Among the brain imaging techniques developed during the past two decades positron emission tomography has the highest sensitivity, allowing the analysis of specific neurotransmitter mechanisms in the living human brain. By using a combination of selective ligands labelled with positron emitting isotopes, D1 and D2 dopamine, serotonin 5HT2 and benzodiazepine receptors were examined in schizophrenic patients (DSM-IIIR) and healthy control subjects. With this technique receptor populations could be excellently visualized and quantified with regard to number and binding characteristics in several brain regions. The characteristics of total D1 and D2 dopamine receptor populations in the caudate and putamen did not differ significantly in young drug naive schizophrenic patients and age matched control subjects. On the other hand, there was a highly significant reduction of the D1 signal in high intensity regions of the basal ganglia when [11C]SCH 23390, a selective D1 dopamine receptor antagonist, was used. These results suggest the possibility of a reduced D1 dopamine receptor density in the patch compartment of the basal ganglia in schizophrenia. For 5HT2 and benzodiazepine receptors no major alteration of receptor characteristics was observed in several neocortical and limbic brain regions.

In vivo demonstration of altered benzodiazepine receptor density in patients with generalised epilepsy

Electrophysiological data suggest that an abnormal oscillatory pattern of discharge in cortical and thalamic neurons may be the major mechanism underlying primary generalised epilepsy. No neurochemical or anatomical substrate for this theory has hitherto been demonstrated in humans and the pathophysiology of primary generalised epilepsy remains unknown. By means of PET and the benzodiazepine (BZ) ligand [11C]flumazenil it has been previously shown that the BZ receptor density is reduced in the epileptic foci of patients with partial epilepsy. In the present study the method was further developed and used in a comparative analysis of cortical, cerebellar, and subcortical BZ receptor binding in patients with primary generalised tonic and clonic seizures (n = 8), and healthy controls (n = 8). Patients with generalised seizures had an increased BZ receptor density in the cerebellar nuclei (p = 0.006) and decreased density in the thalamus (p = 0.003). No significant changes were seen in the cerebral and cerebellar cortex or in the basal ganglia. The observed alterations suggest that the gamma-amino-butyric acid (GABA)-BZ system may be affected in the cerebello-thalamocortical loop of patients with generalised epilepsy and indicate possible targets for selective pharmacological treatment.

Saturation analysis in PET--analysis of errors due to imperfect reference regions

In the determination of specific binding in receptor binding techniques in vitro as well as in vivo, determination of the nonspecific binding as well as the free component is of crucial importance. If a low proportion of specific binding is included when determining the nonspecific binding, relatively large errors may be obtained. In the present study, benzodiazepine (BZ) receptor binding in the human brain was determined in vivo using position emission tomography (PET) by applying a saturation procedure using [11C]flumazenil as an example of this problem. Analysis of the errors in Bmax and KD obtained using Scatchard analysis in PET was performed using a priori information from in vitro [3H]flumazenil binding in the pons, used normally as a reference region in BZ receptor binding studies. Even if the density of BZ receptors in the reference region pons is only 2% compared to that in the frontal cortex, this small proportion of specific binding sites will result in a 10% error in the Bmax and KD values. Simulation of a number of Scatchard plots was performed at varying ratios between the nonspecific and the specific binding.

PET-determination of benzodiazepine receptor binding in studies on alcoholism

Positron Emission Tomography (PET) and the radioligand [11C]flumazenil were used to examine benzodiazepine (BZ) receptor binding in the human brain. In a first study of healthy males acute ingestion of alcohol did not alter total radioactivity uptake or specific [11C]flumazenil binding in the neocortex or cerebellum. In a second study [11C]flumazenil binding was determined in 5 healthy male controls and 5 chronic alcohol dependent men using a saturation procedure with two PET experiments. Mean values for BZ-receptor density and affinity were similar in the two groups but the Bmax variance for the alcohol dependents was significantly larger (p < 0.05) for all regions. The present studies do not support the view that alcohol affects central BZ receptor binding in man.

PET analysis of [11C]flumazenil binding to benzodiazepine receptors in chronic alcohol-dependent men and healthy controls

Benzodiazepine (BZ) receptor binding in the brain was determined in five chronic alcohol-dependent men and in five healthy male control subjects using [11C]flumazenil (Ro 15-1788) and positron emission tomography (PET). Magnetic resonance imaging was used to evaluate brain anatomy and pathology, and to define regions of interest in the brain. [11C]Flumazenil binding was quantified by applying a saturation procedure with two PET experiments, the first with high (400-3400 Ci/mmol) and the second with low (approximately 1 Ci/mmol) specific radioactivity. Radioactivity in the pons was taken as an estimate of free and nonspecifically bound radioligand. Equilibrium was defined to prevail when the derivative of specific binding (dCb(t)/dt) was equal to zero. The values were used in a Scatchard analysis for determination of the maximum density of binding sites (Bmax) and the equilibrium binding constant (Kd). The mean values of Bmax and Kd were about the same in the two groups, but the Bmax variance for the alcoholics was significantly greater for all regions of interest as compared with the healthy volunteers. The results may indicate that chronic alcohol consumption has multiple effects on the BZ receptor complex.

Central D2-dopamine receptor occupancy in relation to antipsychotic drug effects: a double-blind PET study of schizophrenic patients

The relationship between central D2-dopamine receptor occupancy and antipsychotic drug effects was examined in a double-blind study. Raclopride was the compound used to induce a selective occupancy of the D2-dopamine receptors. In addition, 11C-labeled raclopride was the radioligand used to measure occupancy by positron emission tomography (PET). Seventeen schizophrenic patients were randomly assigned to one of three parallel groups treated for 4 weeks with daily doses of 2, 6, or 12 mg of raclopride. D2-receptor occupancy was determined by PET at steady-state conditions in 13 patients who completed the study. A statistically significant relationship was demonstrated between antipsychotic effect and degree of D2-receptor occupancy (p < 0.05). Patients with extrapyramidal side effects had significantly higher D2-receptor occupancy than those without (p = 0.02). The finding of a relationship between selective occupancy of the D2-dopamine receptors and clinical effects in schizophrenic patients principally provides new support for the dopamine hypothesis of antipsychotic drug action.

Positron emission tomographic analysis of central D1 and D2 dopamine receptor occupancy in patients treated with classical neuroleptics and clozapine. Relation to extrapyramidal side effects

Positron emission tomography and selective radioligands were used to determine D1 and D2 dopamine receptor occupancy induced by neuroleptics in the basal ganglia of drug-treated schizophrenic patients. In 22 patients treated with conventional dosages of classical neuroleptics, the D2 occupancy was 70% to 89%. Patients with acute extrapyramidal syndromes had a higher D2 occupancy than those without side effects. This finding indicates that neuroleptic-induced extrapyramidal syndromes are related to the degree of central D2 occupancy induced in the basal ganglia. In five patients treated with clozapine, the prototype atypical antipsychotic drug, a lower D2 occupancy of 38% to 63% was found. This finding demonstrates that clozapine is also "atypical" with respect to the central D2 occupancy in patients. During treatment with clozapine, there is a low frequency of extrapyramidal syndromes, which accordingly may reflect the comparatively low D2 occupancy induced by clinical doses of clozapine. Classical neuroleptics, like haloperidol or sulpiride, did not cause any evident D1 occupancy, but the thioxanthene flupentixol induced a 36% to 44% occupancy. In four patients treated with clozapine, the D1 occupancy was 38% to 52%. The D1 occupancy induced by clozapine and flupentixol may contribute to the antipsychotic effect of these drugs.

PET analysis of alcohol interaction with the brain disposition of [11C]flumazenil

Acute alcohol administration to rats has in preliminary studies been reported to drastically increase the binding of the benzodiazepine (BZ) receptor antagonist [3H]flumazenil (Ro 15-1788) to central BZ receptors. In the present study the effect of acute alcohol ingestion on the disposition of [11C]flumazenil in the human brain and plasma was examined by positron emission tomography (PET) in four healthy volunteers. Neocortex, cerebellum and pons (reference region) were delineated using X-ray computerized tomography (CT). Alcohol did not increase either total radioactivity uptake or specific [11C]flumazenil binding in neocortex or cerebellum. However, alcohol had a small but significant effect on [11C]flumazenil in arterial blood. After alcohol the plasma radioactivity peak was higher, more narrow and occurred earlier than in the control experiments. The present experiments contradict the view that alcohol directly affects central BZ receptor binding in man. Thus the dramatic increase of flumazenil binding in rat brain reported previously could not be observed in the human brain.

Anterior cruciate ligament allograft transplantation in dogs

The biomechanical and clinical performance of bone-ligament-bone anterior cruciate ligament (ACL) allografts was studied in eight dogs. Allografts were collected from skeletally mature, healthy dogs using aseptic technique, and stored at -70 degrees for three to five weeks before implantation. The allografts were size-matched to the recipient dogs using ACL length and then rigidly fixed in position with interference screws and Kirschner wires. Three dogs regained a normal gait, and their grafts sustained breaking loads that were 25%, 41%, and 59% of controls. Partial or complete graft failure occurred in the other five dogs at some point in the study. Four had intraligamentous rupture and one had an avulsion fracture of the femoral attachment site. Joint-fluid cytology was normal in all eight dogs. Histologic examination showed persistent lymphoplasmacytic infiltrate. Eventually the allograft cores were incorporated in the host bed. Hyperplasia and fibrosis of the synovial membrane were diffuse and persisted as focal accumulations of mononuclear inflammatory cells.

Maps of receptor binding parameters in the human brain--a kinetic analysis of PET measurements

A kinetic method is described for the estimation of neuroreceptor density as well as the rate constants for association and dissociation of rapidly equilibrating radioligands. The method is exemplified by positron emission tomographic measurements of the human brain using 11C-raclopride, a D 2 dopamine receptor antagonist, and 11C-Ro 15-1788, a benzodiazepine receptor antagonist. Using a linear non iterative algorithm, regional binding characteristics were calculated and displayed pixel by pixel in brain maps. Data from repeated experiments on the same subject with different amounts of the unlabeled ligand were utilized. The binding characteristics were determined according to a two step procedure in which the time course of the free radioligand concentration was estimated from a reference region considered to be free of specific receptor binding sites. Alternative methods to determine the concentration of free radioligand are discussed.

In-vivo demonstration of reduced benzodiazepine receptor binding in human epileptic foci

Ten patients with partial epilepsy and five healthy controls had positron emission tomography (PET) of the brain after intravenous administration of the 11C-labelled benzodiazepine (BZ) receptor ligand 'Ro-15 1788'. In all ten patients BZ receptor binding was significantly lower in the epileptic focus than in the contralateral homotopic reference region and the remaining neocortex. No asymmetries in BZ receptor binding were observed between homotopic reference regions in the controls or the non-epileptic regions of patients. These results demonstrate the potential of the BZ receptor as a biochemical marker for display of epileptic foci by PET, and also strengthen the hypothesis that inhibitory mechanisms are disturbed in the epileptic focus.