T-cell co-stimulation through B7RP-1 and ICOS

T-cell activation requires co-stimulation through receptors such as CD28 and antigen-specific signalling through the T-cell antigen receptor. Here we describe a new murine costimulatory receptor-ligand pair. The receptor, which is related to CD28 and is the homologue of the human protein ICOS, is expressed on activated T cells and resting memory T cells. The ligand, which has homology to B7 molecules and is called B7-related protein-1 (B7RP-1), is expressed on B cells and macrophages. ICOS and B7RP-I do not interact with proteins in the CD28-B7 pathway, and B7RP-1 co-stimulates T cells in vitro independently of CD28. Transgenic mice expressing a B7RP-1-Fc fusion protein show lymphoid hyperplasia in the spleen, lymph nodes and Peyer's patches. Presensitized mice treated with B7RP-1-Fc during antigen challenge show enhanced hypersensitivity. Therefore, B7RP-1 exhibits co-stimulatory activities in vitro and in vivo. ICOS and B7RP-1 define a new and distinct receptor-ligand pair that is structurally related to CD28-B7 and is involved in the adaptive immune response.

Birth defects after maternal exposure to corticosteroids: prospective cohort study and meta-analysis of epidemiological studies

BACKGROUND

Corticosteroids are first-line drugs for the treatment of a variety of conditions in women of childbearing age. Information regarding human pregnancy outcome with corticosteroids is limited.

METHODS

We collected prospectively and followed up 184 women exposed to prednisone in pregnancy and 188 pregnant women who were counseled by Motherisk for nonteratogenic exposure. The primary outcome was the rate of major birth defects. A meta-analysis of all epidemiological studies was conducted. The Mantel-Haenszel summary odds ratio was calculated for the pooled studies with 95% confidence intervals. A cumulative summary odds ratio was also calculated by combining studies in chronological order. Chi-squared for homogeneity was determined to establish the comparability of the studies.

RESULTS

In our prospective study, there was no statistical difference in the rate of major anomalies between the corticosteroid-exposed and control groups. In the meta-analysis, the Mantel-Haenszel summary odds ratio for major malformations with all cohort studies was 1.45 [95% CI 0.80, 2.60] and 3.03 [95% CI 1.08, 8. 54] when Heinonen et al. ('77) was removed. This suggests a marginally increased risk of major malformations after first-trimester exposure to corticosteroids. In addition, summary odds ratio for case-control studies examining oral clefts was significant (3.35 [95% CI 1.97, 5.69]).

CONCLUSIONS

Although prednisone does not represent a major teratogenic risk in humans at therapeutic doses, it does increase by an order of 3.4-fold the risk of oral cleft, which is consistent with the existing animal studies.

Results of treatment of 385 patients with peritoneal surface spread of appendiceal malignancy

INTRODUCTION

In the past, peritoneal carcinomatosis, regardless of primary tumor type, has always been a lethal condition. Recently, special treatments using cytoreductive surgery with peritonectomy procedures combined with perioperative intraperitoneal chemotherapy have resulted in long-term survival. Appendiceal malignancy with a low incidence of liver and lymph node metastases may be especially appropriate for these aggressive local regional treatments.

METHODS

All patients treated with surgery before January 1999 are included. Patients left with gross residual disease after surgery were not given intraperitoneal chemotherapy, but were later treated with intravenous chemotherapy. The intraperitoneal chemotherapy was given in the perioperative period, starting with mitomycin C at 12.5 mg/m2 for males and 10 mg/m2 for females. For patients whose pathology showed adenomucinosis, intraperitoneal chemotherapy was limited to treatment in the operating theater with heated mitomycin C. Patients with mucinous adenocarcinoma or pseudomyxoma/adenocarcinoma hybrid had, in addition to mitomycin C, five consecutive days of intraperitoneal 5-fluorouracil at 650 mg/m2 instilled in 1-1.5 liters of 1.5% dextrose peritoneal dialysis solution. A complete cytoreduction was defined as tumor nodules <2.5 mm in diameter remaining after surgery. The histopathology categorized the patients as having adenomucinosis, adenomucinosis/carcinomatosis hybrid, or mucinous carcinomatosis. A previous surgical score was used to estimate the extent of previous surgical procedures.

RESULTS

The morbidity of treated patients was 27% and the mortality was 2.7%. In a multivariate analysis, prognostic factors for survival included the completeness of cytoreduction (P < .0001), the histopathological character of the appendix malignancy (P < .0001), and the extent of previous surgical interventions (P = .001). Patients with a complete cytoreduction and adenomucinosis by pathology had a 5-year survival of 86%; with hybrid pathology, survival at 5 years was 50%. Incomplete cytoreduction had a 5-year survival of 20% and 0% at 10 years.

CONCLUSIONS

Cytoreductive surgery and perioperative intraperitoneal chemotherapy can be used to salvage selected patients with peritoneal surface spread of appendiceal primary tumors. Similar strategies for other patients with peritoneal surface malignancy such as peritoneal carcinomatosis from colon or gastric cancer, peritoneal sarcomatosis, or peritoneal mesothelioma should be pursued.

An activated form of Notch influences the choice between CD4 and CD8 T cell lineages

Notch is a transmembrane receptor that controls cell fate decisions in Drosophila and whose role in mammalian cell fate decisions is beginning to be explored. We are investigating the role of Notch in a well-studied mammalian cell fate decision: the choice between the CD8 and CD4 T cell lineages. Here we report that expression of an activated form of Notch1 in developing T cells of the mouse leads to both an increase in CD8 lineage T cells and a decrease in CD4 lineage T cells. Expression of activated Notch permits the development of mature CD8 lineage thymocytes even in the absence of class I major histocompatability complex (MHC) proteins, ligands that are normally required for the development of these cells. However, activated Notch is not sufficient to promote CD8 cell development when both class I and class II MHC are absent. These results implicate Notch as a participant in the CD4 versus CD8 lineage decision.

Induction of midbrain dopaminergic neurons by Sonic hedgehog

Midbrain dopaminergic neurons, whose loss in adults results in Parkinson's disease, can be specified during embryonic development by a contact-dependent signal from floor plate cells. Here we show that the amino-terminal product of Sonic hedgehog autoproteolysis (SHH-N), an inductive signal expressed by floor plate cells, can induce dopaminergic neurons in vitro. We show further that manipulations to increase the activity of cyclic AMP-dependent protein kinase A, which is known to antagonize hedgehog signaling, can block dopaminergic neuron induction by floor plate cells. Our results and those of other studies indicate that SHH-N can function in a dose-dependent manner to induce different cell types within the neural tube. Our results also provide the basis for a potential cell transplantation therapy for Parkinson's disease.

Notch activity influences the alphabeta versus gammadelta T cell lineage decision

The choice between the alphabeta or gammadelta T cell fates is influenced by the production of functional, in-frame rearrangements of the TCR genes, but the mechanism that controls the lineage choice is not known. Here, we show that T cells that are heterozygous for a mutation of the Notch1 gene are more likely to develop as gammadelta T cells than as alphabeta T cells, implying that reduced Notch activity favors the gammadelta T cell fate over the alphabeta T cell fate. A constitutively activated form of Notch produces a reciprocal phenotype and induces thymocytes that have functional gammadeltaTCR gene rearrangements to adopt the alphabeta T cell fate. Our data indicate that Notch acts together with the newly formed T cell antigen receptor to direct the alphabeta versus gammadelta T cell lineage decision.

Morbidity and mortality analysis of 200 treatments with cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy using the coliseum technique

BACKGROUND

Peritoneal carcinomatosis from gastrointestinal cancers is a fatal diagnosis without special combined surgical and chemotherapy interventions. Guidelines for cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy (HIIC) by using the Coliseum technique have been developed to treat patients with peritoneal carcinomatosis and other peritoneal surface malignancies. The purpose of this study was to analyze the morbidity and mortality of patients undergoing cytoreductive surgery and HIIC by using mitomycin C.

METHODS

Data were prospectively recorded on 183 patients who underwent 200 cytoreductive surgeries with HIIC between November 1994 and June 1998. Seventeen of the 183 patients returned for a second-look surgery plus HIIC. All HIIC administrations occurred after cytoreduction and used continuous manual separation of intra-abdominal structures to optimize drug and heat distribution. Origins of the tumors were as follows: appendix (150 patients), colon (20 patients), stomach (7 patients), pancreas (2 patients), small bowel (1 patient), rectum (1 patient), gallbladder (1 patient), and peritoneal papillary serous carcinoma (1 patient). Morbidity was organized into 20 categories that were graded 0 to IV by the National Cancer Institute's Common Toxicity Criteria. In an attempt to identify patient characteristics that may predispose to complications, each morbidity variable was analyzed for an association with the 25 clinical variables recorded.

RESULTS

Combined grade III/IV morbidity was 27.0%. Complications observed included the following: peripancreatitis (6.0%), fistula (4.5%), postoperative bleeding (4.5%), and hematological toxicity (4.0%). Morbidity was statistically linked with the following clinical variables: duration of surgery (P < .0001), the number of peritonectomy procedures and resections (P < .0001), and the number of suture lines (P = .0078). No HIIC variables were statistically associated with the presence of grade III or grade IV morbidity. Treatment-related mortality was 1.5%.

CONCLUSIONS

HIIC may be applied to select patients with peritoneal carcinomatosis from gastrointestinal malignancies with 27.0% major morbidity and 1.5% treatment-related mortality. The frequency of complications was associated with the extent of the surgical procedure and not with variables associated with the delivery of heated intraoperative intraperitoneal chemotherapy. The technique has shown an acceptable frequency of adverse events to be tested in phase III adjuvant trials.

Severe B cell hyperplasia and autoimmune disease in TALL-1 transgenic mice

TALL-1/Blys/BAFF is a member of the tumor necrosis factor (TNF) ligand superfamily that is functionally involved in B cell proliferation. Here, we describe B cell hyperplasia and autoimmune lupus-like changes in transgenic mice expressing TALL-1 under the control of a beta-actin promoter. The TALL-1 transgenic mice showed severe enlargement of spleen, lymph nodes, and Peyer's patches because of an increased number of B220+ cells. The transgenic mice also had hypergammaglobulinemia contributed by elevations of serum IgM, IgG, IgA, and IgE. In addition, a phenotype similar to autoimmune lupus-like disease was also seen in TALL-1 transgenic mice, characterized by the presence of autoantibodies to nuclear antigens and immune complex deposits in the kidney. Prolonged survival and hyperactivity of transgenic B cells may contribute to the autoimmune lupus-like phenotype in these animals. Our studies further confirm TALL-1 as a stimulator of B cells that affect Ig production. Thus, TALL-1 may be a primary mediator in B cell-associated autoimmune diseases.

Platelet factor 4 is chemotactic for neutrophils and monocytes

Platelet factor 4 is shown to be a chemotactic protein for human polymorphonuclear leukocytes and monocytes at concentrations found in human serum and reached locally in injured tissue. The maximum chemotactic response to platelet factor 4 nearly equals that achieved with saturating concentrations of the chemotactic activity derived from the fifth component of human complement, C5. Cells desensitized to C5 chemotactic activity retain chemotactic responsiveness to platelet factor 4. Serum contains inhibitory capacity against the chemotactic activity associated with platelet factor 4. Our results suggest that the local release of platelet factor 4 may be an important stimulus attracting inflammatory cells to sites of blood vessel injury.

Evidence for a protective role of pulmonary surfactant protein D (SP-D) against influenza A viruses

We tested the hypothesis that pulmonary surfactant-associated lectins--surfactant proteins A and D (SP-A, and -D)--contribute to initial protective mechanisms against influenza A viruses (IAVs). SP-D potently inhibited hemagglutination activity of several strains of IAV as well as causing viral aggregation. SP-D enhanced neutrophil binding of IAV and neutrophil respiratory burst responses to the virus. Neutrophil dysfunction resulting from IAV exposure was diminished when the virus was pre-incubated with SP-D. Each of these effects was mediated by the calcium-dependent carbohydrate-binding property of SP-D. Native SP-D preparations of both human and rat origin, as well as recombinant rat SP-D, had similar activity. SP-A also inhibited IAV hemagglutination activity. We have previously reported that related mammalian serum lectins (mannose-binding lectin [MBL] and conglutinin) have similar effects. SP-D was at least 10-fold more potent at causing hemagglutination inhibition than were SP-A or MBL. SP-D was shown to contribute to potent anti-IAV activity of human bronchoalveolar lavage fluid. These results suggest that SP-D--alone, and in conjunction with SP-A and phagocytic cells--constitutes an important component of the natural immune response to IAV infection within the respiratory tract.

Thymosin alpha1: isolation and sequence analysis of an immunologically active thymic polypeptide

The amino acid sequence of a biologically active polypeptide isolated from calf thymus, termed thymosin alpha1, has been determined. Thymosin alpha1 is a heat stable, highly acidic molecule composed of 28 amino acid residues. This peptide is one of several present in thymosin fraction 5 that may participate in the regulation, differentiation and function of thymus-dependent lymphocytes (T cells). A nomenclature for the family of polypeptides present in thymosin fraction 5 is suggested.

Analysis of morbidity and mortality in 60 patients with peritoneal carcinomatosis treated by cytoreductive surgery and heated intraoperative intraperitoneal chemotherapy

BACKGROUND

Peritoneal carcinoma has been regarded as a uniformly lethal clinical entity. A treatment plan combining cytoreductive surgery and heated intraoperative intraperitoneal chemotherapy (HIIC) was devised and tested to treat such patients. The purpose of this study was to evaluate the morbidity and mortality associated with this treatment approach.

METHODS

Sixty patients with peritoneal carcinomatosis from adenocarcinoma of the colon or appendix were included in the study. Extensive cytoreductive surgery was combined with heated intraperitoneal mitomycin in an intraoperative lavage technique followed by one cycle of early postoperative intraperitoneal 5-fluorouracil. Eleven clinical variables were selected and statistically correlated with morbidity and mortality.

RESULTS

Twenty-five complications occurred in 21 patients (morbidity = 35%). Morbidity related to gastrointestinal function included anastomotic leak (n=6), bowel perforations (n=5), bile leak (n=3), and pancreatitis (n=2). Four patients presented with severe hematologic toxicity (Grade 3 or 4). There were three cases of postoperative bleeding, one case of abdominal wound dehiscence, and one case of pulmonary embolism. Morbidity was significantly associated with three clinical factors: male sex, high intraabdominal temperature during HIIC, and duration of the surgical procedure. Enteral complications (bowel fistula and anastomotic leak) occurred in patients with a significantly higher number of peritonectomy procedures and a significantly longer operation. Three patients died within 8 weeks after the procedure (mortality = 5%). Mortality was significantly associated with age and intraabdominal temperature.

CONCLUSIONS

Cytoreductive surgery combined with HIIC is associated with a 35% morbidity rate and a 5% mortality rate. Extensive surgery (duration and number of peritonectomy procedures) and high intraabdominal temperature represent the major risk factors for postoperative morbidity and mortality of patients treated with this new therapeutic approach.

Effects of meal ingestion on plasma amylin concentration in NIDDM and nondiabetic humans

Recent interest has focused on the potential role of amylin in the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM). This 37-amino acid peptide is found in extracellular amyloid deposits in approximately 50% of pancreatic islets of patients with NIDDM and has been shown to inhibit skeletal muscle glycogen synthesis in vitro. Immunocytochemical studies have colocalized amylin and insulin within beta-cell secretory granules in nondiabetic humans, provoking the following questions. Is amylin cosecreted with insulin? Are circulating amylin concentrations higher in patients with NIDDM either before or after food ingestion? To answer these questions, we developed a sensitive and specific immunoassay to measure plasma concentrations of amylin in humans. Use of this assay indicated that, in lean nondiabetic subjects, glucose ingestion resulted in an increase (P less than 0.001) in the plasma concentration of amylin (from 2.03 +/- 0.22 to 3.78 +/- 0.39 pM) and insulin (from 48.3 +/- 3.1 to 265 +/- 44 pM). There was a significant correlation between the concentrations of insulin and amylin (r = 0.74, P less than 0.001) and the increase in insulin and amylin concentration (r = 0.65, P less than 0.005). Fasting concentrations of amylin did not differ in diabetic and weight-matched nondiabetic subjects and showed a similar pattern of change after ingestion of a mixed meal. We conclude that amylin is secreted in response to ingestion of either glucose or a mixed meal and circulates at concentrations that do not differ in patients with NIDDM and nondiabetic subjects. It remains to be determined whether amylin at physiological concentrations influences carbohydrate metabolism and if so whether its effects differ in diabetic and nondiabetic humans.

Detection of platelet-derived growth factor (PDGF)-AA in actively healing human wounds treated with recombinant PDGF-BB and absence of PDGF in chronic nonhealing wounds

Some human chronic dermal wounds treated with recombinant platelet-derived growth factor-BB (rPDGF-BB) show increased healing coupled with fibroblast activation and granulation tissue formation. To determine whether endogenous PDGF is associated with healing and nonhealing dermal ulcer phenotypes, we developed monoclonal antibodies capable of recognizing the three isoforms of PDGF, AA, AB, and BB dimers, and capable of discriminating between two alternatively spliced A chain transcripts. We detected little PDGF isoform expression in normal skin and in nonhealing dermal ulcers. In contrast, in surgically created acute wounds and chronic ulcers treated with rPDGF-BB, markedly upregulated levels of PDGF-AA (long form) were found. In both types of wounds, increased PDGF-AA was detected primarily in capillaries and fibroblasts, although in rPDGF-BB-treated chronic wounds, widespread expression of PDGF-AA was somewhat delayed. With continued treatment, the long form of PDGF-AA, which can preferentially bind extracellular matrix, was expressed only in capillaries, while fibroblasts began synthesizing the short form of PDGF-AA. Within capillaries, all endothelial cells and varying numbers of pericytes and smooth muscle cells contained PDGF-AA. In all wounds, macrophages and keratinocytes were not a major contributor. While PDGF-BB and PDGF-AB were present in a minority of healing wounds, they were usually present at lower levels than PDGF-AA. PDGF-beta receptors, which bind only PDGF-BB and not other isoforms, were found in normal skin and granulation tissue, providing a molecular basis for treating human chronic wounds with exogenous rPDGF-BB.

Purification and biochemical characterization of CP4 (SP-D), a collagenous surfactant-associated protein

CP4 is a collagenous glycoprotein (43 kDa, reduced) synthesized by rat type II pulmonary epithelial cells in primary culture (Persson et al., 1988). In order to better characterize this protein, CP4 was isolated from rat bronchoalveolar lavage and EDTA extracts of lung surfactant by adsorption to barium sulfate and elution with sodium citrate followed by reverse-phase HPLC. Amino acid analysis of purified CP4 demonstrated 4-hydroxyproline (Hyp), hydroxylysine (Hyl), and acid-labile components coeluting with Hyl glycosides. In addition, gas-phase amino-terminal microsequencing of two CP4 CNBr peptides demonstrated nonoverlapping collagenous sequences comprised of nine and six Gly-X-Y triplets, containing a total of four residues of Hyp and two of Hyl. There was less than 50% sequence homology of these peptides with the cDNA-derived sequence of the collagenous domain of rat SP-A. Two-dimensional IEF/SDS-PAGE resolved the protein into a charge train of basic isoforms (pI approximately 6-8), similar to those of newly synthesized CP4 and the class D surfactant proteins (Phelps & Taeusch, 1985). Gel filtration of nondenatured CP4 on 4% agarose showed a high apparent molecular mass complex comprised of disulfide-bonded trimers of the 43-kDa subunits. Antibodies to purified lavage CP4 showed specific binding to newly synthesized and surfactant-associated CP4. We propose that CP4 be designated "surfactant protein D" (SP-D) in accordance with an accepted nomenclature for surfactant-associated proteins.

Transformation of NIH 3T3 cells by HER3 or HER4 receptors requires the presence of HER1 or HER2

Members of the epidermal growth factor receptor (EGFR) subfamily of receptor protein tyrosine kinases have been implicated in the pathogenesis of various malignancies. The ability of one EGFR subfamily member to influence, or function synergistically with, another is likely to be a general feature of these receptors. To assess the role of receptor heterodimerization, we analyzed the ability of Neu differentiation factor (NDF) to induce cell growth and transformation of NIH 3T3 cells transfected with different combinations of the EGFR subfamily of receptors. NDF induced mitogenesis, but not transformation, of cells expressing either HER3 or HER4 alone. However, NDF-induced cell transformation was observed when either HER1 or HER2 was coexpressed with HER3 or HER4. In analogous receptor phosphorylation experiments, NDF-induced transphosphorylation appears to be correlated with synergistic transformation of NIH 3T3 cells. Interestingly, transphosphorylation between HER1 and HER4 can be stimulated by either EGF or NDF.

Amino acid sequence of rabbit muscle aldolase and the structure of the active center

Elucidation of the amino acid sequence of fructose-1,6-bis-phosphate aldolase from rabbit muscle has made it possible to assign the positions of the functional groups known to play specific roles in the catalytic activity, and also to locate the buried, exposed, and active site cysteine residues. The results indicate that the middle portion of the polypeptide chain, including Cys-134, Cys-149, Cys-177, and Cys-l99, is buried in the native structure, with regions containing Cys-72, Lys-107, Lys-227, Cys-336, His-359, and the COOH-terminal residue (Tyr-361) folded into the active center of the enzyme, at or near the surface of the enzyme molecule.

Surfactant protein D interacts with Pneumocystis carinii and mediates organism adherence to alveolar macrophages

Pneumocystis carinii interacts with glycoproteins present in the lower respiratory tract through its mannose-rich surface antigen complex termed gpA. Surfactant protein D (SP-D) is a recently described component of the airspace lining material that possesses a calcium-dependent lectin domain capable of interacting with glycoconjugates present on microorganisms and leukocytes. Accordingly, we evaluated the extent and localization of SP-D in the lower respiratory tract during Pneumocystis pneumonia in an immunosuppressed rat model and examined its role in modulating interaction of P. carinii with macrophages. We report that SP-D is a major component of the alveolar exudates that typify P. carinii pneumonia and is present bound to the surface of P. carinii organisms in vivo. We further demonstrate that SP-D binds to P. carinii through saccharide-mediated interactions with gpA present on the surface of the organism. Lastly, we show that SP-D augments binding of P. carinii to alveolar macrophages, but does not significantly enhance macrophage phagocytosis of the organism. The interaction of SP-D with gpA represents an additional important component of the host-parasite relationship during P. carinii pneumonia.

Prospective randomized trial of early postoperative intraperitoneal chemotherapy as an adjuvant to resectable gastric cancer

OBJECTIVE

Surgeons have postulated on numerous occasions that cancer resection may participate in the dissemination of a malignancy. This randomized trial sought to determine whether a large volume of chemotherapy solution used perioperatively to flood the peritoneal cavity could eliminate microscopic residual disease and thereby improve survival of patients with gastric cancer.

SUMMARY BACKGROUND DATA

Surgical treatment failures in patients with gastric cancer are confined to the abdomen in most patients. Resection site and peritoneal surface spread, along with liver metastases, are the most common areas of recurrence. Survival and quality of life of patients with gastric cancer would be improved if disease progression at these anatomic sites was reduced.

METHODS

In a prospective randomized trial of 248 patients, intraperitoneal mitomycin C on day 1 and intraperitoneal 5-fluorouracil on days 2 through 5 were administered after gastric cancer resection. Patients who were thought to have stage II or stage III disease were randomized after resection to surgery alone versus surgery plus early postoperative intraperitoneal chemotherapy. After final pathologic examinations, there were 39 patients with stage I, 50 with stage II 95 with stage III, and 64 with resected stage IV cancer.

RESULTS

The 5-year survival of the surgery-only group was 29.3%, and the surgery-plus-intraperitoneal chemotherapy group was 38.7% (p = 0.219). In a subset analysis, the patients with stage I, stage II, and stage IV disease showed no statistically significant difference in survival. The 5-year survival rate of patients with stage III disease who underwent surgery only was 18.4% versus a survival rate of 49.1% for patients who underwent surgery plus intraperitoneal chemotherapy (p = 0.011).

CONCLUSIONS

In a subset analysis, patients with stage III gastric cancer have shown a statistically significant improvement in survival when treated with perioperative intraperitoneal chemotherapy. Further studies in patients with gastric cancer with surgically directed chemotherapy are suggested.

Design, synthesis, and biological activity of peptides which release growth hormone in vitro

Experimental observations showed that the analogs [D-Trp2]- and [D-Phe2]methionine enkephalin amide were weakly active in releasing GH from rat pituitary in vitro. These observations were used to design more active GH-releasing factors. Conformational energy calculations were carried out, and energetically favored conformations of these polypeptides were found. Structural similarities as well as structural differences between active and inactive analogs were examined, and new sequences were predicted. Progressively more active analogs were designed, then synthesized, and tested. This cycle of steps was repeated, each time using structural and chemical concepts as design guides, until a series of very active analogs resulted. The most active analog to date, Tyr-D-Trp-Ala-Trp-D-Phe-NH2, was shown to release GH in vitro at 10-30 ng/ml medium, which is approximately 10(3) times more active than the two starting enkephalin-based analogs. From the structure-activity data, a mechanism for binding at the receptors is formulated, and a comparison is made between the structural relationships of the GH-releasing peptide analogs and the GH inhibitor, somatostatin.

Results of treatment of 33 patients with peritoneal mesothelioma

BACKGROUND

Peritoneal mesothelioma is a rare peritoneal malignancy, representing approximately one-third of all mesotheliomas. It is regarded as a universally fatal cancer with few treatment options.

METHODS

Records of 33 patients with peritoneal mesothelioma were reviewed retrospectively. Demographic, clinical and quantitative prognostic indicators were evaluated and analysed statistically using survival as endpoint. Patients were treated by a uniform strategy involving cytoreductive surgery with peritonectomy procedures and perioperative intraperitoneal chemotherapy (cisplatin, doxorubicin).

RESULTS

There were ten women and 23 men; mean age was 53.0 years. Asbestos exposure was recorded in five patients and a family history of cancer in 13. Presentation was mainly abdominal distension and pain. Median survival was 31.0 months; overall projected survival at 3 years was 56 per cent. The most significant positive predictive factors of survival were: female sex (P= 0.003), low prior surgical score (P=0.002), completeness of cytoreduction (P=0.0002) and second-look surgery (P=0.019). The morbidity rate for this combined treatment was 33 per cent and the perioperative mortality rate was 3 per cent.

CONCLUSION

Although peritoneal mesothelioma is rare, progress in its management has occurred. Survival has been extended and selection factors by which patients may be allocated to aggressive management strategies have been defined.

Brain neurons and glial cells express Neu differentiation factor/heregulin: a survival factor for astrocytes

Neu differentiation factor (NDF, also called heregulin) was isolated from mesenchymal cells on the basis of its ability to elevate phosphorylation of ErbB proteins. Earlier in situ hybridization analysis showed that NDF was transcribed predominantly in the central nervous system during embryonic development. To gain insights into the role of NDF in brain we analyzed its distribution by immunohistochemistry and in situ hybridization. Late-gestation (day 17) rat embryos displayed high NDF immunoreactivity in both motor (e.g., putamen) and limbic (e.g., septum) regions. Lower levels of the factor were exhibited by adult brain, except for the cerebellum, where NDF expression was increased postnatally. Both neurons and glial cells were identified by immunohistochemistry as NDF-producing cells (e.g., pyramidal neurons in the cerebral cortex and glial cells in the corpus callosum). By establishment of primary cultures of rat brain cells we confirmed that NDF was expressed in neurons as well as in astrocytes. In addition, by using such primary cultures we observed that NDF treatment exerted only a limited mitogenic effect, which was accompanied by significant acceleration of astrocyte maturation. Furthermore, long-term incubation with the factor specifically protected astrocytes from apoptosis, implying that NDF functions in brain as a survival and maturation factor for astrocytes.