Preclinical tolerance evaluation of the addition of a cisplatin-based dry powder for inhalation to the conventional carboplatin-paclitaxel doublet for treatment of non-small cell lung cancer

Despite the advances in targeted therapies and immunotherapy for non-small cell lung cancer (NSCLC) patients, the intravenous administration of carboplatin (CARB) and paclitaxel (PTX) in well-spaced cycles is widely indicated for the treatment of NSCLC from stage II to stage IV. Our strategy was to add a controlled-release cisplatin-based dry-powder for inhalation (CIS-DPI-ET) to the conventional CARB-PTX-IV doublet, administered during the treatment off-cycles to intensify the therapeutic response while avoiding the impairment of pulmonary, renal and haematological tolerance of these combinations. The co-administration of CIS-DPI-ET (0.5 mg/kg) and CARB-PTX-IV (17-10 mg/kg) the same day showed a higher proportion of neutrophils in BALF (35 ± 7% vs 1.3 ± 0.8%), with earlier regenerative anaemia than with CARB-PTX-IV alone. A first strategy of CARB-PTX-IV dose reduction by 25% also induced neutrophil recruitment, but in a lower proportion than with the first combination (20 ± 6% vs 0.3 ± 0.3%) and avoiding regenerative anaemia. A second strategy of delaying CIS-DPI-ET and CARB-PTX-IV administrations by 24 h avoided both the recruitment of neutrophils in BALF and regenerative anaemia. Moreover, all these groups showed higher cytotoxicity (LDH activity, protein content) with no higher renal toxicities. These two strategies seem interesting to be assessed in terms of antitumor efficacy in mice.

Pulmonary and renal tolerance of cisplatin-based regimens combining intravenous and endotracheal routes for lung cancer treatment in mice

Despite recent advances, platinum-based chemotherapy (partially composed of cisplatin, CIS) remains the backbone of non-small-cell lung cancer treatment. As CIS presents a cumulative and dose-limiting nephrotoxicity, it is currently administered with an interruption phase of 3-4 weeks between treatment cycles. During these periods, the patient recovers from the treatment side effects but so does the tumour. Our strategy is to increase the treatment frequency by delivering a cisplatin controlled-release dry powder for inhalation (CIS-DPI) formulation during these off-cycles to expose the tumour environment for longer to CIS, increasing its effectiveness. This is promising as long as the pulmonary and renal toxicities remain acceptable. The aim of the present investigation was to evaluate the pulmonary and renal tolerance of CIS-DPI (three times per cycle) and CIS using the intravenous (IV) route (CIS-IV) (one time per cycle) as monotherapies and to optimize their combination in terms of dose and schedule. At the maximum tolerated dose (MTD), combining CIS-DPI and CIS-IV impaired the pulmonary and the renal tolerance. Therefore, pulmonary tolerance was improved when the CIS-IV dose was decreased by 25% (to 1.5 mg/kg) while maintaining the MTD for CIS-DPI. In addition to this dose adjustment, a delay of 24 h between CIS-DPI and CIS-IV administrations limited the acute kidney injury.

Molecular mechanisms involved in vasoactive intestinal peptide receptor activation and regulation: current knowledge, similarities to and differences from the A family of G-protein-coupled receptors

An actual paradigm for activation and regulation of the GPCR (G-protein-coupled receptors)/seven-transmembrane helix family of receptors essentially emerges from extensive studies of the largest family of receptors, the GPCR-A/rhodopsin family. The mechanisms regulating the GPCR-B family signal transduction are less precisely understood due in part to the lack of the conserved signatures of the GPCR-A family (E/DRY, NPXXY) and in part to the absence of a reliable receptor modelling, although some studies suggest that both families share similar features. Here, we try to highlight the current knowledge of the activation and the regulation of the VIP (vasoactive intestinal peptide) receptors, namely VPAC (VIP/pituitary adenylate cyclase-activating peptide receptor) 1 and 2. This includes search for amino acids involved in the stabilization of the receptor active conformation and in coupling to G-proteins, signalling pathways activated in response to VIP, agonist-dependent receptor down-regulation, phosphorylation and internalization as well as pharmacological consequences of receptor hetero-dimerization.

Sentinel lymph node biopsy is associated with a significantly improved survival compared to level Iand II axillary lymph node dissection in node-negative breast cancer patients

609

Background: The sentinel lymph node (SLN) biopsy has emerged as the standard of care in evaluating the axillary lymph node status in early stage breast cancer patients. It is well known that step sectioning and immunohistochemistry of the SLN allow for a more accurate histopathologic examination. Conversely, it remains to be elucidated whether or not the more accurate SLN staging is associated with improved survival. Therefore, the objective of the present investigation was to evaluate if patients undergoing a SLN biopsy have an improved disease-free and overall survival compared to those undergoing ALND. Methods: From our prospective database 355 node negative patients with early stage breast cancer (pT1 und pT2 <=3cm, pN0/pNSN0) were assessed. Patients underwent either ALND (n=178) in the years 1990–1997 or a SLN biopsy (n=177) in 1998–2004. Long-term disease-free and overall survival were analysed for both groups. Log-rank tests were used for unadjusted analyses, a Cox proportional hazard regression model for risk-adjusted analyses. Results: The median follow- up was 48.2 months in the SLN group and 120.0 months in the ALND group. Patients in the SLN group had a significantly better disease-free (p=0.012) and overall survival (p=0.04) compared to the ALND group. In Cox proportional hazard regression analysis, the performed procedure (SLN compared to ALND) was an independent predictor for improved disease-free survival (hazard ratio 0.28, 95% confidence interval 0.11–0.75, p=0.011) and overall survival (hazard ratio 0.36, 95% confidence interval 0.14–0.89, p=0.027). Conclusion: The present analysis - the first one in the literature - provides compelling evidence that patients with a negative SLN have a significantly improved disease-free and overall survival compared to node negative patients undergoing ALND. This relevant finding is most likely due to an improved histopathologic staging accuracy. The significant survival benefit of node negative patients having SLN biopsy highlights yet another important advantage of the SLN concept in breast cancer.

No significant financial relationships to disclose.

[Surgery for morbid obesity: restrictive or rather malabsorptive procedures?]

Die morbide Adipositas stellt ein erhebliches medizinisches und gesellschaftliches Problem dar. Die chirurgische Behandlung ist heutzutage die einzige effiziente Therapieform zur dauerhaften, nachhaltigen Gewichtsreduktion bei Patienten mit einem Body Mass Index über 40 kg/m². Die bariatrischen Operationen werden unterschieden in restriktive, malabsorptive oder Kombinationsverfahren. Alle gängigen Operationsverfahren haben sich grundsätzlich als effizient erwiesen mit einer Reduktion des Übergewichtes zwischen 50–80%. Komorbiditäten und Lebensqualität werden signifikant verbessert. Die Operations-Mortalität ist gering (0–1%). Der minimal-invasive Zugang mittels Laparoskopie stellt den Standard dar. Verfahren mit einer vornehmlich restriktiven Komponente zeigen insgesamt weniger Komplikationen sowohl im Kurz- als auch Langzeitverlauf. Unter den restriktiven Verfahren hat sich die Magenbypass-Operation als Standardmethode weltweit etabliert. Die bariatrische Chirurgie stellt letzten Endes nur ein Modul einer multimodalen und interdisziplinären Therapie dar. Dazu gehören auch Änderungen des Lebensstils, psychologische Betreuung, Ernährungsberatung und metabolische Kontrolle.

Breast cancer sagittal/horizontal plane location influences axillary lymph node involvement

AIM

To assess the influence of tumour location on axillary lymph node involvement (ALNI) and prognosis in breast cancer by evaluating the significance of the sagittal/horizontal alignment.

METHODS

We compared 57 patients with superficially located breast carcinomas up to 3.0 cm with patients having lesions in posterior planes of the breast. Both groups were matched according to age, time of diagnosis, tumour size, grade, hormonal receptor status and tumour site within the frontal plane. Histologic evidence of skin involvement, excluding tumours fulfilling the criteria for pT4b, was defined as inclusion criteria and reference plane for superficial tumour location.

RESULTS

Tumours situated in the superficial region of the breast, compared to those located in deeper planes, have an increased risk of ALNI (p=0.023), whereas no difference was observed with reference to disease-specific survival (p=0.203).

CONCLUSION

This study shows that ALNI is dependent on sagittal/horizontal as well as frontal tumour location. Clinicians should be aware that tumours lying posteriorly may be at increased risk of occult spread outside axillary lymph nodes.

Scope and significance of non-uniform classification practices in breast cancer with non-inflammatory skin involvement: a clinicopathologic study and an international survey

BACKGROUND

The study evaluates the scope of non-uniform classification practices concerning breast carcinomas with non-inflammatory skin involvement.

PATIENTS AND METHODS

We compared the clinical course of patients with histologically proven non-inflammatory skin involvement: 119 (65.4%) with clinically obvious 'classical' skin changes (Group A) and 63 (34.6%) with no or only discreet changes (Group B). A questionnaire was circulated to pathology departments in 24 countries to assess the practice concerning the placement of skin- involved breast carcinomas in the TNM classification.

RESULTS

Patients in Group B showed a significantly better disease specific survival (P=0.0002). Eighty-six respondents (70.5%) of the survey preferred the 'histological view' and classified tumors with only histological proven skin involvement as T 4 b/stage IIIB. The opposing classification principle ('clinical view'), which dictates that T 4 b breast cancer is a clinical diagnosis and the classical signs must be present, was supported by 31 respondents (25.4%).

CONCLUSIONS

A large number of breast cancer patients with non-inflammatory skin involvement are only histologically proven and show, compared with cases exhibiting the classical clinical signs, significant differences in clinical course and prognosis. In general, both subsets were aggregated in one T category/stage (T 4 b/IIIB). This results in a considerable distortion of the reported statistical data.

Retroperitoneoscopic Living Donor Nephrectomy: A Comparison With the Open Approach in Respect of Early Postoperative Pain Management

INTRODUCTION

We retrospectively compared perioperative donor outcomes and early postoperative pain control after retroperitoneoscopic (RLDN) and standard open (OLDN) living donor nephrectomy.

METHODS

One hundred donors included fifty after RLDN (37 women/13 men) and 50 after OLDN (35 women/15 men) were retrospectively analyzed for basic analgesics, for opioid consumption, and for visual analog scale (VAS) to verify the experienced pain. The donors were questioned in the morning and evening of the first through fifth postoperative days.

RESULTS

The mean age of both groups was equal. The mean operating time was 149.7 +/- 48.2 minutes (60 to 270) for RLDN and 164.1 +/- 30.3 minutes (60 to 240) for OLDN (P = NS). The mean warm ischemia time was 120 +/- 36 seconds (50 to 240) and 114 +/- 31 seconds (60 to 190) for the RLDN and OLDN groups, respectively (P = NS). The mean evening VAS for RLDN versus OLDN on postoperative days 1 to 5 was: 2.1 versus 2.2 (P = NS), 0.9 versus 1.8 (P = .009), 0.5 versus 1.3 (P = .016), 0.1 versus 0.7 (P = .013), and 0.1 versus 0.7 (P = .013), respectively. In both groups there was a tendency toward a higher VAS score in the morning than in the evening. RLDN donors showed significantly earlier period free of pain (VAS = 0) than those after OLDN. There was a significant difference of being free from any opiate between both groups after surgery.

CONCLUSIONS

After RLDN donors experienced less postoperative pain than after OLDN over the early postoperative days. Therefore, postoperative regional anesthesia is not necessary for donors operated by a retroperitoneoscopic approach.

Long-term outcomes of breast cancer patients after endoscopic axillary lymph node dissection: a prospective analysis of 52 patients

BACKGROUND

Reports on long-term outcomes after endoscopic axillary lymph node dissection (ALND) of breast cancer patients are still lacking in the medical literature. The objective of this prospective study was to assess the oncological and functional outcomes in breast cancer patients after endoscopic ALND.

METHODS

Fifty-five breast cancer patients were prospectively enrolled, of whom 52 were available for follow-up with a median of 71.9 months (range 11-96). The following oncological and functional endpoints were evaluated during follow-up at several time points: occurrence of local, axillary and distant metastases, seroma or infection, shoulder mobility (range of motion), numbness, pain, presence of lymphoedema as well as restriction in activities of daily living.

RESULTS

In 52 patients endoscopic ALND of level I and II was successfully performed. Two port-site metastases (2/52, 4%) occurred, one of which in a patient with negative axillary lymph nodes. The same patient suffered from the only axillary recurrence (1/52, 2%). Three patients (3/52, 6%) developed lymphoedema. No other functional adverse events (shoulder mobility, pain, numbness, hypertrophic scar) were noticed at the end of the observation period.

CONCLUSION

The present investigation with long-term follow-up after endoscopic ALND--the first one in the literature--reveals minor morbidity, good functional and cosmetic results. In contrary to conventional surgery, the endoscopic procedure is associated with the occurrence of port-site metastases, not seen in the open approach. Axillary recurrences do not appear more frequently when compared with results after conventional ALND. In the meantime the less invasive sentinel lymph node (SLN) biopsy is the established standard technique in evaluating the axillary lymph node status.

Changes in bone mineral content after surgical treatment of morbid obesity

Weight loss reduces bone mass and increases the risk of osteoporosis. This study was undertaken to assess changes of bone metabolism following Roux-en-Y gastric bypass (RYGB) and adjustable silicone gastric banding (ASGB) as compared to nonoperated controls of morbidly obese subjects. Fourteen female and 5 male patients with a mean (+/-SEM) age of 44.3 +/- 1.8 years participated in the 24-month prospective study. Nine patients underwent ASGB, 4 patients RYGB operation, and 6 patients were included in the control group. Bone metabolism was assessed by determination of serum parathyroid hormone (PTH), osteocalcin, urinary deoxypyridinoline, and dual energy x-ray absorptiometry (DXA) before, and 6, 12, and 24 months after intervention. The body mass index (BMI) decreased from 41.0 +/- 1.1 to 34.0 +/- 1.4 kg/m2 in the ASGB group (P = .001), from 42.7 +/- 2.2 to 30.5 +/- 2.2 kg/m2 in the RYGB group (P = .006), and remained unchanged in the control group (from 41.2 +/- 1.2 to 41.4 +/- 1.4 kg/m2) after 24 months. Bone mineral content (BMC) showed no significant change in the ASGB group (from 3,079 +/- 140 to 3,064 +/- 129 g) and in the control group (from 2,945 +/- 130 to 2,940 +/- 111 g), whereas it decreased from 2,968 +/- 111 to 2,621 +/- 139 g in the RYGB group (P = .005). The loss in BMC was accompanied by significant increases in urinary deoxypyridinoline (P < .05) and in serum osteocalcin (P < .01) after RYGB, suggesting both, increased bone resorption and increased bone formation. The authors were aware of the fact that the study groups were small and conclusions need to be regarded as preliminary. However, the RYGB operation resulted in enhanced weight loss and significant net loss of bone mass in comparison to ASGB and obese control subjects. Patients losing large amounts of body weight should be monitored regularly regarding prevention of osteoporosis.

Peritoneal Mesothelioma after Environmental Asbestos Exposure

Mesothelioma are primary malignant neoplasms of the serous membranes. They usually involve the pleura and rarely the pericardium, the peritoneum and the tunica vaginalis testis. About 90% are associated with exposure to asbestos. The exposure is generally occupational, an environmental inhalation of asbestos and asbestiform fibers in areas in Turkey has been observed and presents a major health problem. This report of a patient from Anatolia with peritoneal mesothelioma after environmental exposure outlines the importance of considering this pathology in the differential diagnosis of a Turkish patient presenting with ascites.

Diagnosis of malignant hyperthermia susceptibility during CABG surgery

A 55-year-old man presented for coronary artery bypass graft (CABG) surgery. Malignant hyperthermia (MH) was suspected in his family. This case report describes a diagnostic approach to obtain a definite MH diagnosis by performing an in vitro contracture test at the time of CABG surgery in combination with molecular genetic investigations.

Lysine 195 and aspartate 196 in the first extracellular loop of the VPAC1 receptor are essential for high affinity binding of agonists but not of antagonists

The role in ligand recognition and receptor activation of two adjacent charged residues (lysine 195 and aspartate 196) in the first extracellular loop of the human VPAC(1) receptor was investigated in stably transfected CHO cells expressing the wild type or point mutated receptors.Replacement of lysine 195 by glutamine or of aspartate 196 by asparagine reduced the agonists' ability to stimulate adenylate cyclase activity; VIP behaved like a partial agonist and a partial agonist behaved as an antagonist. The receptor's capacity to recognize agonists was reduced but antagonists' affinity was unaffected. Both results suggesting that the two charged residues are essential for VPAC(1) receptor activation. On the other hand, the double mutant was less severely affected than single mutants suggesting that hydrogen bonds may partially compensate the loss of charged residues. But the inversion of the residues affected receptor recognition and activation more markedly suggesting that the two charged residues do not interact directly.

A small sequence in the third intracellular loop of the VPAC(1) receptor is responsible for its efficient coupling to the calcium effector

The stimulatory effect of vasoactive intestinal peptide (VIP) on the intracellular calcium concentration ([Ca(2+)](i)) has been investigated in Chinese hamster ovary cells stably transfected with the reporter gene aequorin, and expressing human VPAC(1), VPAC(2), chimaeric VPAC(1)/VPAC(2) or mutated receptors. The VIP-induced increase in [Ca(2+)](i) was linearly correlated with receptor density, and was higher in cells expressing VPAC(1) receptors than in cells expressing a similar density of VPAC(2) receptors. The study was performed to establish the receptor sequence responsible for this difference. VPAC(1)/VPAC(2) chimaeric receptors were first used for broad positioning: those receptors having the third intracellular loop (IC3) of the VPAC(1) or the VPAC(2) receptor behaved, in this respect, phenotypically like VPAC(1) and VPAC(2) receptors respectively. Replacement in the VPAC(2) receptor of the sequence comprising residues 315-318 (VGGN) within IC3 by its VPAC(1) receptor counterpart (residues 328-331; IRKS) and the introduction of VGGN instead of IRKS into VPAC(1) was sufficient to mimic VPAC(1) and VPAC(2) receptor characteristics respectively. Thus a small sequence in the IC3 domain of the VPAC(1) receptor is responsible for the efficient agonist-stimulated increase in [Ca(2+)](i).

Two tyrosine residues in the first transmembrane helix of the human vasoactive intestinal peptide receptors play a role in supporting the active conformation

1: We investigated the human vasoactive intestinal polypeptide (VIP) receptors VPAC(1) and VPAC(2) mutated at conserved tyrosine residues in the first transmembrane helix (VPAC(1) receptor Y146A and Y150A and VPAC(2) receptor Y130A and Y134A). 2: [(125)I]-Acetyl-His(1) [D-Phe(2), K(15), R(16), L(27)]-VIP (1-7)/GRF (8-27) (referred to as [(125)I]-VPAC(1) antagonist) labelled VPAC(1) binding sites, that displayed high and low affinities for VIP (IC(50) values and per cent of high affinity binding sites: wild-type, 1 nM (57+/-9%) and 160 nM; Y146A, 30 nM (40+/-8%) and 800 nM; Y150A, 4 nM (27+/-8%) and 300 nM). [R(16)]-VIP behaved as a "super agonist" at both mutated VPAC(1) receptors and the efficacies of VIP analogues modified in positions 1, 3 and 6 were significantly decreased. 3: VIP was less potent at the Y130A and Y134A mutated VPAC(2) receptors (EC(50) 200 and 400 nM, respectively) than at the wild-type VPAC(2) receptor (EC(50) 7 nM). Furthermore, [hexanoyl-His(1)]-VIP behaved as a "super agonist" at the two mutated VPAC(2) receptors, and VIP analogues modified in positions 1, 3 and 6 were less potent and efficient at the mutated than at wild-type VPAC(2) receptors. However, the Y130A and Y134A mutants could not be studied in binding assays. 4: Our results suggest that the conserved tyrosine residues do not interact directly with the VIP His(1), Asp(3) or Phe(6) residues (that are necessary for receptor activation), but stabilize the correct active receptor conformation.

[Malignant transformation of perianal Buschke-Löwenstein tumor. Extensive abdominoperineal rectum excision and reconstruction with transpelvic myocutaneous rectus abdominis muscle flap]

INTRODUCTION

The Buschke Löwenstein tumor (giant condyloma) in its perianal variant is an extremely rare disease caused by human papilloma virus. Although of histologically benign appearance, it infiltrates and destroys the surrounding tissue. There is a high risk of local recurrence and malignant transformation. The treatment of choice is wide surgical resection.

CASE

A 56-year-old woman presented with perianal giant condyloma infiltrating the rectum and vagina. The extensive soft tissue defect resulting from wide resection was filled with a transpelvic myocutaneous rectus abdominis flap. Histology showed a squamous cell carcinoma arising in the Buschke Löwenstein tumor with clear resection margins. Therefore, the patient was irradiated locally after uneventful primary wound healing.

CONCLUSION

A simultaneous reconstruction of a large pelvinoperineal soft tissue defect with the transpelvic myocutaneous rectus abdominis flap allows primary healing, accelerated rehabilitation, and safe adjuvant radiotherapy without risk of serious radiation damage to the small bowel by preventing it from protruding into the pelvic defect.

The genome sequence of Schizosaccharomyces pombe

We have sequenced and annotated the genome of fission yeast (Schizosaccharomyces pombe), which contains the smallest number of protein-coding genes yet recorded for a eukaryote: 4,824. The centromeres are between 35 and 110 kilobases (kb) and contain related repeats including a highly conserved 1.8-kb element. Regions upstream of genes are longer than in budding yeast (Saccharomyces cerevisiae), possibly reflecting more-extended control regions. Some 43% of the genes contain introns, of which there are 4,730. Fifty genes have significant similarity with human disease genes; half of these are cancer related. We identify highly conserved genes important for eukaryotic cell organization including those required for the cytoskeleton, compartmentation, cell-cycle control, proteolysis, protein phosphorylation and RNA splicing. These genes may have originated with the appearance of eukaryotic life. Few similarly conserved genes that are important for multicellular organization were identified, suggesting that the transition from prokaryotes to eukaryotes required more new genes than did the transition from unicellular to multicellular organization.

Characterization of functional VIP/PACAP receptors in the human erythroleukemic HEL cell line

The presence of VIP/PACAP receptors was investigated on the human erythroleukemic cell line HEL. Specific binding of [125I]-PACAP or [125I]-VIP on HEL cells or membranes was very low and did not allow to perform competition curves. At 37 degrees C PACAP transiently increased cAMP levels in the presence of the non-specific phosphodiesterase inhibitor IBMX, suggesting rapid desensitization. Kinetic studies revealed that optimal conditions to measure the EC(50) of PACAP(1-27) were 10 min at 20 degrees C. Under those conditions, PACAP-related peptides increased cAMP levels with EC(50) in agreement with the pharmacological profile of the VPAC(1) receptor subtype: PACAP = VIP > [K(15), R(16,) L(27)]VIP(1-7)/GRF(8-27) = [R(16)]ChSn (two VPAC(1) agonists) >> helodermin = secretin. RO 25-1553, a selective activator of VPAC(2) receptor was inactive at 1 microM. Dose-response curves of VPAC(1) agonist molecules (PACAP, VIP, [K(15), R(16), L(27)]VIP(1-7)/GRF(8-27), [R(16)]ChSn) were shifted to the right by the VPAC(1) receptor antagonist [AcHis(1), D-Phe(2), Lys(15), Leu(17)]VIP(3-7)/GRF(8-27), with a K(i) of 3 +/- 1 nM (n = 3). The presence of VPAC(1) receptor mRNA was confirmed by RT-PCR. Preincubation with PACAP or PMA showed that VPAC(1) receptors underwent homologous and heterologous desensitization. This study provides the first evidence for the expression of functional VPAC(1) receptors undergoing rapid desensitization in HEL cells.

Vasoactive intestinal peptide (VIP) stimulates [Ca2+]i and cyclic AMPin CHO cells expressing Galpha16

The stimulatory effect of vasoactive intestinal peptide (VIP) and analogues on [Ca2+]i has been investigated in chinese hamster ovary (CHO) cells stably transfected with the reporter gene aequorin, and expressing either the human VPAC1or VPAC2 receptor in absence or in presence of the Galpha16. In cells that were not transfected with Galpha16 and expressed a similar density of receptors, the VIP induced [Ca2+]i ncrease was higher in VPAC1 than in VPAC2 receptor expressing cells. In aequorin/Galpha16 cotransfected cells, the VIP-induced response was higher, reaching 70 to 80% of the maximal calcium response, obtained after digitonin treatment, in response to both VPAC1 and VPAC2 receptor stimulation. The results suggest that in hematopoietic cells, which express both VIP receptors and Galpha16, the signalling pathway of VIP could be mediated through both cyclic AMP and [Ca2+]i increase.

Mutational analysis of the human vasoactive intestinal peptide receptor subtype VPAC(2): role of basic residues in the second transmembrane helix

1. We investigated the role of two conserved basic residues in the second transmembrane helix arginine 172 (R172) and lysine 179 (K179) of the VPAC(2) receptor. 2. Vasoactive intestinal polypeptide (VIP) activated VPAC(2) receptors with an EC(50) value of 7 nM, as compared to 150, 190 and 4000 nM at R172L, R172Q and K179Q-VPAC(2) receptors, respectively. It was inactive at K179I mutated VPAC(2) receptors. These results suggested that both basic residues were probably implicated in receptor recognition and activation. 3. The VPAC(2)-selective VIP analogue, [hexanoyl-His(1)]-VIP (C(6)-VIP), had a higher affinity and efficacy as compared to VIP at the mutated receptors. 4. VIP, Asn(3)-VIP and Gln(3)-VIP activated adenylate cyclase through R172Q receptors with EC(50) values of 190, 2 and 2 nM, respectively, and through R172L receptors with EC(50) values of 150, 12 and 8 nM, respectively. Asn(3)-VIP and Gln(3)-VIP behaved as partial agonists at the wild type receptor, with E(max) values (in per cent of VIP) of 75 and 52%, respectively. In contrast, they were more efficient than VIP (E(max) values of 150 and 150% at the R172Q VPAC(2) receptors, and of 400 and 360% at the R172L receptors, respectively). These results suggested that the receptor's R172 and the ligand's aspartate 3 are brought in close proximity in the active ligand-receptor complex. 5. The K179I and K179Q mutated receptors had a lower affinity than the wild-type receptors for all the agonists tested in this work: we were unable to identify the VIP amino acid(s) that interact with K179.

Two basic residues of the h-VPAC1 receptor second transmembrane helix are essential for ligand binding and signal transduction

We mutated the vasoactive intestinal peptide (VIP) Asp(3) residue and two VPAC(1) receptor second transmembrane helix basic residues (Arg(188) and Lys(195)). VIP had a lower affinity for R188Q, R188L, K195Q, and K195I VPAC(1) receptors than for VPAC(1) receptors. [Asn(3)] VIP and [Gln(3)] VIP had lower affinities than VIP for VPAC(1) receptors but higher affinities for the mutant receptors; the two basic amino acids facilitated the introduction of the negatively charged aspartate inside the transmembrane domain. The resulting interaction was necessary for receptor activation. 1/[Asn(3)] VIP and [Gln(3)] VIP were partial agonists at VPAC(1) receptors; 2/VIP did not fully activate the K195Q, K195I, R188Q, and R188L VPAC(1) receptors; a VIP analogue ([Arg(16)] VIP) was more efficient than VIP at the four mutated receptors; and [Asn(3)] VIP and [Gln(3)] VIP were more efficient than VIP at the R188Q and R188L VPAC(1) receptors; 3/the [Asp(3)] negative charge did not contribute to the recognition of the VIP(1) antagonist, [AcHis(1),D-Phe(2),Lys(15),Arg(16),Leu(27)] VIP ()/growth hormone releasing factor (8-27). This is the first demonstration that, to activate the VPAC(1) receptor, the Asp(3) side chain of VIP must penetrate within the transmembrane domain, in close proximity to two highly conserved basic amino acids from transmembrane 2.

Advanced breast biopsy instrumentation for the evaluation of impalpable lesions: a reliable diagnostic tool with little therapeutic potential

OBJECTIVE

To assess the potential of advanced breast biopsy instrumentation (ABBI) to clarify the diagnosis of impalpable mammographic lesions and to remove the entire malignant lesions with clear margins.

DESIGN

Prospective assessment in a consecutive series of patients.

SETTING

University hospital, Basel, Switzerland.

SUBJECTS

139 patients presenting with 144 impalpable microcalcifications or solid nodular densities evident on screening and follow-up mammograms that were suspicious of malignancy.

MAIN OUTCOME MEASURES

Feasibility, sensitivity, efficiency in obtaining definitive diagnoses in an outpatient clinic under local anaesthesia, feasibility of complete removal of a primary malignancy, and intervention-related morbidity.

RESULTS

The ABBI procedure was successful in 135/144 (94%); an accurate diagnosis was made in 129/130 patients followed up (99%), sensitivity for malignant lesions was 31/32 (97%) and there were 2 complications (2%). Margins of the biopsy cylinder contained a malignant lesion in 26/31 (84%).

CONCLUSIONS

Excisional biopsy using the ABBI system is a reliable diagnostic tool with a low morbidity. As in other published series margins were often not clear of tumour and therefore the therapeutic use of the ABBI procedure is limited.

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[Significance of endoscopic axillary dissection in invasive breast carcinoma after introduction of the "sentinel lymph node" method]

Axillary clearance provides prognostic information, determines adjuvant therapy and reduces axillary recurrences. However significant morbidity may follow axillary dissection. Patients with small tumors (pT1a-c) may benefit from new less invasive (endoscopic lymph node dissection) or more selective (sentinel lymph node biopsy) axillary procedures which recently have been introduced. In this prospective study the axilloscopic approach was evaluated.

PATIENTS AND METHODS

55 clinically node negative patients (mean age: 60 years [30-86]) had endoscopic axillary surgery by one single surgeon (1.1996-6.1998). After axillary liposuction individual lymph nodes (level I + II) were identified and removed under direct vision by means of a laparoscope (successful procedure in 95%; n = 52). Patients were followed every four months according to a institution based follow up protocol. Results of 51 patients (1 refused) were analyzed after a median follow up of 22 (7-37) months by self-evaluation questionnaire, interview and clinical examination (including: range of motion of the shoulder joint, circumferences of the upper extremities).

RESULTS

An average of 13.3 (5-25) lymph nodes was endoscopically removed. Patients (n = 16; 31%) had involved nodes with a mean of 3.1 nodes positive per individuum. Seromas necessitated needle aspiration in 8 patients (15%). There were no hematomas and one low grade infection (2%). After a median follow up period of 22 (7-37) months no axillary relapse but one trocar site implantation metastasis (1/55, 2%) was detected and resected. No lymph edema was observed. Early range of motion of the shoulder joint was excellent.

CONCLUSION

This technique allows the removal of an adequate number of lymph nodes for staging as well as for regional control. The morbidity is low and the medium-term follow-up results are promising. The atraumatic and very well tolerated endoscopic axillary dissection is being replaced by the selective sentinel lymph node procedure.

[The Advanced Breast Biopsy Instrumentation (ABBI) for evaluation of mammographically suspicious, non-palpable findings of the breast: a reliable diagnosis with minor therapeutic potential]

BACKGROUND

Stereotactic biopsy techniques supersede conventional hook-wire localization followed by open excision to clarify the dignity of nonpalpable mammographic lesions. The advanced breast biopsy instrumentation (ABBI) allows stereotactically guided excision of a specimen up to 20 mm in diameter on an outpatient basis under local anaesthesia.

METHODS

Demographic information, mammographic and pathological findings, complications, subsequent interventions and sensitivity as well as efficiency of a series of 144 planned ABBI procedures were documented (largest published single institution series).

RESULTS

The ABBI procedure was successfully performed in 93.8% (135/144); accurate diagnosis was made in 99.3% (134/135), sensitivity for malignant lesions was 96.9% (31/32) and morbidity was 1.5%. Consistent with other published series margins of the biopsy cylinder containing a malignant lesion were involved in 83.9% (26/31).

CONCLUSIONS

Excisional biopsy using the ABBI system is a reliable diagnostic tool with a low incidence of morbidity. The therapeutic use is of limited potential.

[Validation study of the sentinel lymph node (SLN) method in invasive breast carcinoma. Personal data and review of the literature]

BACKGROUND

Axillary lymph node dissection (ALND) is an integral part in the therapy of breast cancer. Axillary lymph node involvement and tumour size are the most important prognostic factors. Restriction of ALND to level I and II (Berg) reduced high morbidity. The increasing proportion of patients with early breast cancer and negative axillary nodes led to a more selective method to avoid unnecessary ALND. The sentinel lymph node (SLN)--the first draining lymph node of a tumour--represents the status of the axilla. A negative SLN prevents from further completion ALND.

PATIENTS AND METHODS

From 9/97 to 1/99 44 patients with invasive breast cancer underwent a prospective trial of lymphatic mapping with isosulfanblue and/or lymphoscintigraphy with 99m technetium-labelled human colloid. During the operation a hand-held gamma probe was used for detection. The SLN was removed selectively and examined by routine histopathology (H&E) and immunohistochemistry (IHC). ALND of level I and II was performed in all patients for correlation.

RESULTS

The SLN were identified in 41 of 44 patients (93%). 2.4 SLN per patient were harvested, overall 17.6 axillary lymph nodes. Of the 41 patients, 21 patients had positive, 20 patients negative SLN. In the 20 patients with negative SLN only one patient (5%) had metastatic disease on complete dissection (negative predictive value of 95%). In 17 patients with positive axillary lymph nodes 16 were found to have positive SLN, only one SLN was negative (false negative rate of 5.9%). In two of 41 patients micrometastases were detected by IHC. Lymphoscintigraphy revealed drainage to the axilla and internal mammary nodes in two of 28 cases (7%).

SUMMARY

Our validation study proves the reproducibility and reliability of the SLN procedure. A multidisciplinary approach is indispensable. The SLN procedure has the potency for becoming the selection criterion whether to perform an ALND or not. Multiple sections and IHC staining improve the detection rate of metastatic disease. Ongoing long time investigations will determine the impact on overall survival. Our own data are discussed in an extended review of the literature.

Expression of vascular endothelial growth factor (VEGF) and VEGF receptors in human neuroblastomas

BACKGROUND

Vascular endothelial growth factor (VEGF) is a specific endothelial cell mitogen that stimulates angiogenesis and plays a crucial role in tumor growth. The aim of the present study was to evaluate the expression of VEGF and of its two high-affinity tyrosine kinase receptors (KDR and Flt-1) in neuroblastoma surgical samples and cell lines.

PROCEDURE

The VEGF, KDR, and Flt-1 mRNA expression in neuroblastoma surgical samples and cell lines was studied by RT-PCR. The receptors were identified in [(125)I]VEGF binding and in functional studies (effect on cell growth). VEGF production by neuroblastomas was investigated by the ELISA method.

RESULTS

It was possible to observe the mRNAs encoding for VEGF and its two receptors in some of the surgical specimens examined, including most of the high-grade tumors. It was also possible to demonstrate that the SK-N-BE cell line expressed VEGF, KDR, and Flt-1 mRNAs as well as biologically active receptors: The cells bound [(125)I]-VEGF, and their growth was stimulated by exogenous VEGF. Moreover, VEGF protein could be detected in their culture conditioned medium.

CONCLUSIONS

These results suggest that, in addition to its effect on angiogenesis, VEGF may affect neuroblastoma cell growth directly and could be an autocrine growth factor.

Eriochrome Black T inhibits endothelial cell growth through S-phase blockade

We used human umbilical vein endothelial cells (HUVEC) cultures to investigate in vitro the antiproliferative effects of suramin and of its analogue, Eriochrome Black T. The cell cycle phases of interest were characterised with specific immune sera raised against cyclin D(1), cyclin E and proliferating nuclear cell antigen (PCNA). Simultaneous detection of two cell cycle markers was ensured by double colour immunofluorescence. Both compounds inhibited the endothelial cell growth while Eriochrome Black T was more potent than suramin. Suramin induced HUVEC to accumulate in G1-phase as an increase of the number of cells expressing both cyclin D(1) and PCNA was observed. Eriochrome Black T preferentially blocked them in the early S-phase, as it increased the proportion of cyclin E positive cells. These results suggest that in addition of its more potent antiproliferative effect on endothelial cell growth, Eriochrome Black T acts at another molecular level than suramin.

Expression of vascular endothelial growth factor (VEGF) and VEGF receptors in human neuroblastomas

BACKGROUND

Vascular endothelial growth factor (VEGF) is a specific endothelial cell mitogen that stimulates angiogenesis and plays a crucial role in tumor growth. The aim of the present study was to evaluate the expression of VEGF and of its two high-affinity tyrosine kinase receptors (KDR and Flt-1) in neuroblastoma surgical samples and cell lines.

PROCEDURE

The VEGF, KDR, and Flt-1 mRNA expression in neuroblastoma surgical samples and cell lines was studied by RT-PCR. The receptors were identified in [(125)I]VEGF binding and in functional studies (effect on cell growth). VEGF production by neuroblastomas was investigated by the ELISA method.

RESULTS

It was possible to observe the mRNAs encoding for VEGF and its two receptors in some of the surgical specimens examined, including most of the high-grade tumors. It was also possible to demonstrate that the SK-N-BE cell line expressed VEGF, KDR, and Flt-1 mRNAs as well as biologically active receptors: The cells bound [(125)I]-VEGF, and their growth was stimulated by exogenous VEGF. Moreover, VEGF protein could be detected in their culture conditioned medium.

CONCLUSIONS

These results suggest that, in addition to its effect on angiogenesis, VEGF may affect neuroblastoma cell growth directly and could be an autocrine growth factor.

Mechanisms of tumor angiogenesis and therapeutic implications: angiogenesis inhibitors

Angiogenesis is the development of new blood vessels from the existing vascular bed. In normal conditions this tightly regulated process occurs only during embryonic development, the female reproductive cycle and wound repair. In contrast, in pathological conditions such as malignant growth, atherosclerosis and diabetic retinopathy, angiogenesis becomes persistent due to an imbalance in the interplay between the positive and negative regulatory signals controlling the process. Thus, the control of tumor neovascularization may lead to new therapeutic approaches. Indeed, several anti-angiogenic drugs are currently undergoing preclinical characterization and/or clinical investigation. Recent achievement has clarified the mechanisms of action leading to pathological angiogenesis and has highlighted the role of hypoxia, growth factors, growth factor-receptors, enzymes and cell adhesion molecules involved in the process. This knowledge has permitted the design of receptor antagonists, adhesion molecule blockers and new targeted vascular approaches including gene therapy.

Learning at the computer: evaluation of an intelligent tutoring system

The aim of the study was to test the efficacy of a new courseware. In a pre and post test frame, students were given the software to be used during one semester. A significant increase in the students' general study motivation was shown at the end of the semester. A change in the use and attitudes towards computers could not be observed. In a follow-up survey at the end of the semester, the students stated that the program was indeed helpful and useful but that they have had difficulties with the program's technical aspects and the general use. Furthermore, the results show that the majority of the participating students accepted the program's content, the general study motivation was high and the students showed a significant increase in learning gains, determined by the differences from pre and post test values. Especially students with low pre test values seemed to profit from the additional use of learning material, resp. the presented courseware. At the end of the semester the students with low and middle pre test results showed an increase in performance as well as an alignment in the performance for diagnosing rheumatological diseases to the students of the upper third pre test results.

Ramipril prevents endothelial dysfunction induced by oxidized low-density lipoproteins: a bradykinin-dependent mechanism

We wished to determine whether the acute toxic effects of oxidized LDL are attenuated in aortas isolated from rats chronically treated with an angiotensin-converting enzyme (ACE) inhibitor. In aortic rings incubated with human oxidized LDL (300 microg/mL), the endothelium-dependent relaxations to acetylcholine were attenuated, but not those to A23187 and to nitroprusside. This toxic effect of oxidized LDL was completely prevented in preparations coincubated with oxidized LDL and the nitric oxide (NO) precursor L-arginine (0.3 mmol/L). In aortas isolated from rats orally treated for 6 weeks with 10 mg/kg ramipril (group 1) or 1 mg/kg ramipril (group 2), this toxic effect of oxidized LDL was also markedly attenuated. In contrast, in aortas isolated from rats cotreated with ramipril (10 mg/kg) for 6 weeks and subcutaneous injections of Hoe 140 (a B2 kinin antagonist), 500 microg/kg per day for the last 2 weeks (group 3) or from rats orally treated for 6 weeks with losartan (an AT1-type angiotensin II receptor antagonist), 20 mg/kg (group 4), the inhibitory effect of oxidized LDL on acetylcholine-induced relaxations was similar to that observed in the control group (group 5). Moreover, long-term treatment with ramipril increased relaxations to acetylcholine in groups 1 and 2 and also relaxations to A23187 and aortic cGMP content in group 1, suggesting an enhanced NO availability. Thus, the protective effect of long-term ACE inhibition against the acute vascular toxicity of oxidized LDL is bradykinin dependent and seems to involve a facilitation of NO release via endothelial B2 kinin receptors.

[Preperitoneal prosthesis implantation in surgical management of recurrent inguinal hernia. Retrospective evaluation of our results 1989-1994]

Recurrent inguinal hernia represents a great problem in surgery given the frequency of this operation, with a recurrence rate of 0.5-8%. Re-recurrence after repair without implantation of a prosthesis occurs in 1-23% of cases. We analyzed our results of patients with recurrent inguinal hernia, operated according to the method of Stoppa. Between 1989 and July 1994 there were 58 operations upon 55 patients with an average age of 65 years, 79% of whom had unilateral and 21% bilateral hernias. 89% of all patients underwent surgery because of a recurrent inguinal hernia. A Marlex mesh was used in 79% of the case. All patients were followed up (mean 35 months, minimum 12 months). Early complications consisted in one hematoma (1.7%), which had to be drained, as well as one early recurrence (1.7%). No infections were observed. The overall recurrence rate was 12%. However, 60% of all recurrences occurred in the few first years after introduction of this technique at our clinic; with growing number of operations and experience with Stoppa's technique, we obtained a recurrence rate of 6-7% per year. In our opinion, supported by the results of other studies, Stoppa's technique is a successful method in the treatment of recurrent inguinal hernia.

Aortic valve replacement in elderly patients with aortic stenosis

OBJECTIVE

To assess the risk of aortic valve replacement and long-term follow-up in elderly patients with dominant aortic stenosis.

DESIGN

Retrospective analysis of patients who had aortic valve replacement over a 10 year period and were routinely seen in an outpatient clinic.

SETTING

University hospital.

PATIENTS

93 patients aged > or = 60 and 47 patients > or = 70 years with symptomatic aortic stenosis undergoing aortic valve replacement.

MAIN OUTCOME MEASURES

Early and late mortality in different age groups. Influence of preoperative signs and symptoms on overall outcome.

RESULTS

The proportion of patients older than 70 years increased from 11% in 1978 to 54% in 1986. Perioperative mortality was 3.6% and mortality after 2 and 5 years was 9% and 13% respectively. Survival was similar (85% and 83%, respectively) in patients aged 60-69 years (group 1, n = 93, mean age 64.5 (2.7) and patients aged > or = 70 years (group 2, n = 47, mean age 72.6 (2.5)). Additional coronary artery disease and coronary bypass grafting did not significantly affect survival. The cardiothoracic ratio was inversely related to survival (Cox regression, p < 0.05). Preoperative symptoms (syncope, angina pectoris, and dyspnoea) were similar in both patient groups. After a mean (SD) follow up of 51 (33) months 96% of surviving patients were in NYHA functional class I or II with no difference between the two age groups. Similarly, the cardiothoracic ratio and Sokolow index decreased to near normal values in both age groups.

CONCLUSION

The risk of aortic valve replacement in patients with dominant aortic stenosis is low and not significantly influenced by age. Therefore replacement may be performed without increased risk in elderly patients and with a good long-term outcome.

Type III collagen aminopropeptide levels in serum of patients with progressive systemic scleroderma

Sera from 101 patients with progressive systemic scleroderma were analyzed for circulating aminopropeptides of type III collagen using a radioimmunoassay which measures the intact and degraded forms (Fab assay). About 41% of the patients were found to have values above the normal range. A good correlation was observed between elevated levels of aminopropeptides and the degree of involvement of the skin and internal organs in the patients. Most patients (89%) with an active progression of the disease but not those in a stationary phase showed increased serum levels of aminopropeptides. Treatment with corticosteroids apparently normalized the levels of aminopropeptides. Only minor changes were observed with an antibody-based radioimmunoassay which measures primarily the intact form of the aminopropeptide.

Release of amino-terminal procollagen peptides in paraquat-induced acute pulmonary fibrosis

Acute pulmonary fibrosis following intoxication with paraquat is characterized by increased collagen synthesis and deposition in the lungs. In the present study, a chronic lung lymph fistula preparation in sheep was used to investigate the changes in procollagen type III peptide level in the lung lymph in acute pulmonary distress associated with paraquat application. The procollagen type III peptide is supposed to be an indicator of the changing biosynthetic pattern of pulmonary collagen in lung fibrosis. All animals tested showed a progressive pulmonary distress following the application of paraquat characterized by increasing lymph flows and lymph protein flows which monitored the microvascular membrane damage. In parallel to these findings, procollagen peptide levels in the lymph fluid increased, even before manifest biochemically or histologically detectable pulmonary fibrosis occurred. The present results suggest that the release of procollagen type III peptides into lymph fluid is an early indicator of beginning fibrotic tissue disarrangement, even before completed pulmonary fibrosis can be detected by common tissue analysis.

Serum and urine analysis of the aminoterminal procollagen peptide type III by radioimmunoassay with antibody Fab fragments

A radioimmunoassay based on antibody Fab fragments was developed for the aminoterminal peptide Col 1-3 of bovine type III procollagen. This assay does not distinguish the intact aminopropeptide Col 1-3 from its globular fragment Col 1. Parallel inhibition profiles were observed with human serum and urine allowing the simultaneous quantitative determination of intact and fragmented antigens in these samples. Most of the material has a size similar to that of fragment Col 1 indicating that the aminopropeptide is degraded under physiologic conditions. The concentration of aminopeptide in normal sera was in the range 15-63 ng/ml. Daily excretion was found to be in the range 30-110 micrograms. More than 50% of patients with alcoholic hepatitis and liver cirrhosis showed elevated serum levels of aminopropeptide by the Fab assay. Elevated concentrations were detected more frequently with an antibody radioimmunoassay which measures mainly the intact form of the aminopropeptide. It is suggested that analysis of patients material by both assays could improve their diagnostic application.

Lethal pneumonia in guinea pigs associated with a virus

No bacteria were observed in an epizootic of lethal pneumonia in guinea pigs. Necrotic bronchitis and bronchiolitis with basophilic intranuclear inclusion bodies in bronchial epithelial cells were characteristic. Although adenovirus infection of guinea pigs has not previously been reported, histological findings paralleled those found in adenovirus infections of other animals including man. Virus particles found by electron-microscopical examination of the lung tissue closely resembled adenoviruses. The disease seemed to have a low contagiousness, a low morbidity (about 0.7%), but an acute course and a high mortality (100%).