Abstract 1907: Negative trade-off between neoantigen repertoire breadth and the specificity of HLA-I molecules shapes antitumor immunity

The human leukocyte antigen class I (HLA-I) genes shape our immune response against pathogens and cancer. Certain HLA-I variants can bind a much wider range of peptides than others, a feature that could be favorable against a range of viral diseases. However, the implications of this phenomenon on cancer immune response is unknown. In this paper, we quantified peptide repertoire breadth (or promiscuity) of a representative set of HLA-I alleles, and found that cancer patients that carry HLA-I alleles with high peptide binding promiscuity are characterized by significantly worse prognosis after immune checkpoint inhibitor treatment. This trend can be explained by a reduced capacity of promiscuous HLA-I molecules to discriminate between human self and tumor peptides, yielding a shift in regulation of T-cells in the tumor microenvironment from activation to tolerance. In summary, HLA-I peptide binding specificity shapes neopeptide immunogenicity and the self-immunopeptidome repertoire in an antagonistic manner. It could also underlie a negative trade-off between antitumour immunity and the genetic susceptibility to viral infections.

Citation Format: Benjamin Tamas Papp, Máté Manczinger, Gergő Balogh, Balázs Koncz, Leó Asztalos, Lajos Kemény, Balázs Papp, Csaba Pál. Negative trade-off between neoantigen repertoire breadth and the specificity of HLA-I molecules shapes antitumor immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1907.

Combining immunotherapy with an epidrug in squamous cell carcinomas of different locations: rationale and design of the PEVO basket trial

Squamous cell carcinomas (SCCs) are among the most frequent solid tumors in humans. SCCs, related or not to the human papillomavirus, share common molecular features. Immunotherapies, and specifically immune checkpoint inhibitors, have been shown to improve overall survival in multiple cancer types, including SCCs. However, only a minority of patients experience a durable response with immunotherapy. Epigenetic modulation plays a major role in escaping tumor immunosurveillance and confers resistance to immune checkpoint inhibitors. Preclinical evidence suggests that modulating the epigenome might improve the efficacy of immunotherapy. We herein review the preclinical and the clinical rationale for combining immunotherapy with an epidrug, and detail the design of PEVOsq, a basket clinical trial combining pembrolizumab with vorinostat, a histone deacetylase inhibitor, in patients with SCCs of different locations. Sequential blood and tumor sampling will be collected in order to identify predictive and pharmacodynamics biomarkers of efficacy of the combination. We also present how clinical and biological data will be managed with the aim to enable the development of a prospective integrative platform to allow secure and controlled access to the project data as well as further exploitations.

Abstract B35: Epitope-binding promiscuity of HLA class I molecules shapes the efficacy of checkpoint blockade immunotherapy

Immune checkpoint inhibitors (ICI), which target inhibitory receptors on T cells and thereby promote antitumor immune responses, have achieved considerable success in clinical care against a range of cancer types. However, only a subset of patients responds adequately to ICI-based immunotherapies. Therefore, it is of utmost importance to understand the immunologic mechanisms underlying resistance and adverse effects. It has been previously shown that certain MHC class I molecules are capable of promiscuous peptide binding, as they are associated with a much wider range of epitopes than others. The functional implications of such an elevated epitope-binding repertoire on the efficacy of cancer immunotherapy are unknown. In this work, we examine HLA genotypes of individuals receiving checkpoint blockade immunotherapy using two published cohorts. We demonstrate that cancer patients carrying HLA class I alleles with promiscuous peptide binding display significantly worse prognosis after ICI immunotherapy. This association remains significant after controlling for tumor types, mutational burden, and HLA genetic diversity. We also found that cancer samples of patients carrying highly promiscuous HLA class I alleles display significantly reduced expression of PD1 and CTLA-4 receptors, important markers of T-cell activation in the tumor microenvironment. Moreover, such promiscuous HLA alleles bind neoepitopes with reduced affinity. These findings indicate that high promiscuity is suboptimal due to a reduced specificity of epitope binding, yielding inadequate antitumor immune response.

Citation Format: Máté Manczinger, Gergő Balogh, Balázs Koncz, Lajos Kemény, Balázs Papp, Csaba Pál. Epitope-binding promiscuity of HLA class I molecules shapes the efficacy of checkpoint blockade immunotherapy [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B35.

Breast cancer prevention

We have developed a new approach for breast cancer prevention, capitalizing in the preventive effect of early first full-term pregnancy, hormonally induced differentiation and our ability to identify specific genomic signatures that allow us to predict risk reduction. Early pregnancy imprints in the breast permanent genomic changes or a 'signature' that reduces the susceptibility of this organ to cancer. At cellular level, what we have achieved is the shifting of the Stem Cell 1 population, highly susceptible to cancer, to a population of Stem Cell 2 that is refractory to carcinogenesis. In a case-control study, we have compared the gene expression profile in normal breast tissue from nulliparous and parous postmenopausal women with (case) and without (control) breast cancer. We have determined that early first full-term pregnancy induces a specific genomic signature in the postmenopausal breast that is the biomarker for the Stem cell 2. The Stem cell 2 contains specific genes controlling transcription, RNA processing, immune response, apoptosis and DNA repair. We have further detected in the plasma, using an ELISA assay, the proteins coded by the gene signature. We are developing clinical trials to demonstrate the proof of the principle that r-hCG can induce in the human breast a genomic signature of the Stem cell 2. This is a concept that challenges the currently available chemopreventive agents that need to be given for extended periods for maintaining the suppression of a specific metabolic pathway or the abrogation of the function of an organ.

Cognitive and Affective Endophenotypes Related to Major Depression are Associated with P2RX7

Background:

The P2RX7 gene encoding for purinergic receptor P2X has earlier been associated with a susceptibility to anxiety and affective disorders. The aim of our present study was to investigate the association of this polymorphism with different aspects and symptom clusters of major depression.

Method:

192 inpatients diagnosed with DSM-IV major depression and bipolar I and bipolar II depression aged 21-69 years (mean=48.2±11.05) participated in our study. All participants were evaluated using the Montgomery-Asberg Depression Rating Scale (MADRS). All patients were genotyped for the P2RX7 Gln460Arg SNP (rs2230912) using PCR. Association between genotype and MADRS scores was analysed with ANOVA controlling for age and gender.

Results:

rs2230912 genotype showed a significant association with depression indicated by the total MADRS score. We also found a significant genotype effect in case of the Affective and Cognitive clusters, but not on the Somatic and Psychomotor clusters of MADRS.

Discussion:

We managed to confirm earlier results concerning the association of the P2RX7 rs2230912 with major depressive disorder and bipolar depression. Furthermore, we found that this association is carried by the affective and cognitive symptoms associated with depression. Our results bring us closer to decomposing depression to endophenotypes more suitable for research and also for understanding the nature of affective disorders.

This work was supported by EU-Hungarian fund, GVOP AKF 311 2004 050324/3.0, the Hungarian National fund, OTKA T048576 and Janos Bolyai Research Fellowship of the Hungarian Academy of Science.

Evidence for the notch signaling pathway on the role of estrogen in angiogenesis

We have investigated the molecular mechanisms involved in 17 beta-estradiol-induced angiogenic pathway. We show here that 17 beta-estradiol promoted a 6-fold increase in Jagged1 expression and an 8-fold increase in Notch1 expression by cDNA arrays in breast cancer MCF7 cells. Interestingly, Jagged1 was abrogated by incubation with the estrogen antagonist, ICI182,780. A similar up-regulation of both Notch1 receptor and Jagged1 ligand was found in endothelial cells. Additionally, imperfect estrogen-responsive elements were found in the 5' untranslated region of Notch1 and Jagged1 genes. Treatment with 17 beta-estradiol also led to an activation of Notch signaling in MCF7 cells expressing Notch1 reporter gene or by promoting Jagged1-induced Notch signaling in coculture assays. Inoculation of MCF7 cells in 17 beta-estradiol-treated nude mice resulted in up-regulation of Notch1 expression as well as increased number of tumor microvessels in comparison to placebo-treated mice. Notch1-expressing endothelial cell cultures formed cord-like structures on Matrigel in contrast to cells expressing a dominant-negative form of Notch1, emphasizing the relevance of Notch1 pathway in vessel assembly. Finally, Notch1-expressing MCF7 cells up-regulated hypoxia-inducible factor 1 alpha gene, a well-known angiogenic factor that clustered with Notch1 gene. This study implicates Notch signaling in the cross talk between 17 beta-estradiol and angiogenesis.

The roles of different regions of the CycH protein in c-type cytochrome biogenesis in Sinorhizobium meliloti

Cytochrome c heme lyases encoded by the Sinorhizobium meliloti cycHJKL operon are responsible for generating the covalent bond between the heme prosthetic group and apocytochromes c. The CycH protein with its presumably membrane-associated N-terminal and periplasmic C-terminal parts is thought to be responsible for binding apocytochrome and presenting it to the heme ligation machinery. We propose that these two modules of CycH play roles in different functions of the protein. The N-terminal 96 amino acids represent an active subdomain of the protein, which is able to complement the protoporphyrin IX (PPIX) accumulation phenotype of the cycH mutant strain AT342, suggesting that it is involved in the final steps of heme C biosynthesis. Furthermore, three tetratricopeptide (TPR) domains have been identified in the C-terminal periplasmic region of the CycH protein. TPR domains are known to mediate protein-protein interactions. Each of these CycH domains is absolutely required for protein function, since plasmid constructs carrying cycH genes with in-frame TPR deletions were not able to complement cycH mutants for their nitrate reductase (Rnr-) and nitrogen-fixing (Fix-) phenotypes. We also found that the 309-amino acid N-terminal portion of the CycH, which includes all the TPR domains, is able to mediate the assembly of the c-type cytochromes required for the Rnr+ phenotype. In contrast, only the full-length protein confers the ability to fix nitrogen.

Estimation of impurity profiles of drugs and related materials: part XXI. HPLC/UV/MS study of the impurity profile of ethynodiol diacetate

The impurity profile of ethynodiol diacetate was investigated using the HPLC/UV/MS method. Using the slightly modified HPLC method of USP 24 two impurities, earlier isolated by preparative HPLC and investigated by NMR spectroscopy were separated and characterised. The mass spectra amended by the diode-array UV spectra supported the earlier found structures (E and Z isomers of 17alpha-ethinyl-estr-4-ene-3beta,17-diol-3-acetate-17-(3'-acetoxy-2'-butenoate). Another, hitherto not described impurity, 17alpha-ethinyl-estr-4-ene-3beta,17-diol-3-acetate-17-(3-oxo-butanoate) has also been separated and characterised by means of its mass spectrum, NMR and UV spectra.

[Postoperative lavage treatment of chronic pancreatic abscess]

The authors present their experiences in treatment of chronic pancreatic abscess and infected pancreatic necrosis. In this paper they refer to patients only whose acute necrotizing pancreatitis occurred 4-6 weeks earlier and had intra- and peripancreatic abscesses. They describe their successful lavage method for treatment of pancreatic abscesses. Between 1985 and 1998 they treated 16 patients with only one mortality. The majority of their patients were relatively old and most of them suffered from several severe unrelated diseases. In their opinion, careful dissection and long period of lavage and drainage are a successful method for treating this high-risk surgical group.

Synechocystis HSP17 is an amphitropic protein that stabilizes heat-stressed membranes and binds denatured proteins for subsequent chaperone-mediated refolding

The small heat shock proteins (sHSPs) are ubiquitous stress proteins proposed to act as molecular chaperones to prevent irreversible protein denaturation. We characterized the chaperone activity of Synechocystis HSP17 and found that it has not only protein-protective activity, but also a previously unrecognized ability to stabilize lipid membranes. Like other sHSPs, recombinant Synechocystis HSP17 formed stable complexes with denatured malate dehydrogenase and served as a reservoir for the unfolded substrate, transferring it to the DnaK/DnaJ/GrpE and GroEL/ES chaperone network for subsequent refolding. Large unilamellar vesicles made of synthetic and cyanobacterial lipids were found to modulate this refolding process. Investigation of HSP17-lipid interactions revealed a preference for the liquid crystalline phase and resulted in an elevated physical order in model lipid membranes. Direct evidence for the participation of HSP17 in the control of thylakoid membrane physical state in vivo was gained by examining an hsp17(-) deletion mutant compared with the isogenic wild-type hsp17(+) revertant Synechocystis cells. We suggest that, together with GroEL, HSP17 behaves as an amphitropic protein and plays a dual role. Depending on its membrane or cytosolic location, it may function as a "membrane stabilizing factor" as well as a member of a multichaperone protein-folding network. Membrane association of sHSPs could antagonize the heat-induced hyperfluidization of specific membrane domains and thereby serve to preserve structural and functional integrity of biomembranes.

Adaptation of composition and biophysical properties of phospholipids to temperature by the Crustacean, Gammarus spp

The compositions of lipid classes as well as the molecular species composition of subclasses (diacyl, alkylacyl, and alkenylacyl forms) of choline and ethanolamine phosphoglycerides in marine amphipod crustaceans, Gammarus spp., collected in the Baltic Sea at 8 and 15 degrees C, were studied in relation to environmental temperature. The structural order of phospholipid multibilayers was also determined. Environmental temperature had little effect on fatty acid composition. The level of some polyunsaturated fatty acids, such as 20:4, even increased in choline and ethanolamine phosphoglycerides at 15 degrees C. Ethanolamine phosphoglycerides were rich in alkenylacyl forms, especially in crustaceans collected at 15 degrees C. The accumulation of sn-1 monoenic, sn-2 polyenic diacyl, alkyl, and alkenylacyl phosphatidylethanolamines and diacyl phosphatidylcholines was observed at 8 degrees C. The phospholipid vesicles of crustaceans collected at 8 degrees C were more disordered than expected compared to those obtained from animals collected at 15 degrees C. It was concluded that, in addition to variations in the levels of sn-1 monoenic and sn-2 polyenic phospholipid molecular species with temperature, ethanolamine plasmalogens may play a role in controlling membrane biophysical properties in marine amphipod crustaceans.

1,25(OH)(2)-vitamin D(3) affects the subcellular distribution of protein kinase C isoenzymes in rat duodenum: influence of aging

We have previously shown that the steroid hormone 1, 25-dihydroxy-vitamin D(3) [1,25(OH)(2)D(3)] stimulates total cell protein kinase C (PKC) activity in rat duodenum, an effect that is severely impaired in old animals. We further examined the role of 1, 25(OH)(2)D(3) on PKC as it relates to aging by measuring hormone-induced changes in subcellular localization of PKC activity and isoenzymes in duodenal mucosae from young (three-month-old) and aged (24-month-old) rats. Short treatment of duodenum with 1, 25(OH)(2)D(3) (0.1 nM, 1 min) increased membrane-associated PKC activity, whereas it decreased the activity in the cytosol of young rats but was without significant effect in aged animals. Furthermore, the ability to translocate was present in young animals after a short treatment with the phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA; 100 nM) or dioctanoyl-glycerol (50 microM), whereas the ability was absent in aged rats, suggesting that PKC function was impaired with aging independent of agonist stimulation. The expression of specific PKC isoenzymes and changes in their subcellular distribution after short exposure of the duodenum to the hormone were determined. Western blot analysis of total homogenates using antibodies to various PKC isoforms allowed detection of PKC alpha, beta, and delta. The expression of the straight theta and the zeta isoforms was in addition demonstrated by reverse transcription-polymerase chain reaction. The pattern of isoenzymes present in the duodenum was unaffected by aging. In young rats, 1, 25(OH)(2)D(3) translocates PKC alpha, beta, and delta to the membrane and nucleus; however, no translocation of PKC isoforms was observed in 24-month-old animals in response to the hormone. In summary, in rat duodenum, 1,25(OH)(2)D(3) modulation of PKC activity and isoenzyme subcellular distribution are impaired with aging and may explain age-induced alterations in the intestinal processes under the control of the hormone.

[Surgical treatment of an extremely large sternum protrusion (pectus carinatum)]

The authors present their special surgical treatment by telling the medical history of one of their patients. Cessation of sternum protrusio was achieved by a "H" shape resection of the anterior cortical plate of the sternum.

[Results of parathyroidectomy for primary hyperparathyroidism]

We have performed 16 operations on 14 patients with primary hyperparathyoidism caused by a solitary parathyroid adenoma in our department between 1st jan. 1990-31 dec. 1999. In each case bilateral neck exploration was carried out. As in one case it was located in ectopic neck position, in the other case papillocarcinoma of the thyroid gland and ectopic parathyroid adenoma in mediastinal position were present, primary hyperparathyroidism persisted, so reoperation was needed. Histological examination proved the presence of adenomin all cases. Diffuse hyperplasia and parathyroid cancer did not occur. Before operation all patients underwent US and seven of them had radionuclide scintigraphy. CT scan aided in its localization with four patients. We did not make use of invasive methods, after the first operation 12 patients showed normal S-Ca levels very quickly. In two cases this level was too high after the operation and reoperation was necessary which resulted in normal Ca levels. Even though the number of our cases is rather modest, all the patients recovered. This may prove that we can successfully cure our patients of modern methods of diagnostics used for meticulous examination alongside with careful preparation of the patients by internal specialists are followed by the standard operative techniques available.

[Local antibiotic treatment of chronic thoracic empyema]

The authors present their indications, aims and method for the local antibiotic treatment of chronic empyema thoracis. They analyse the sensitivity and resistant conditions of the most often occurring bacteria, Pseudomonas spp., in an open window treatment of empyema thoracis. 338 patients were treated for intrathoracic suppuration between January 1, 1987 and December 31, 1998. The youngest patient was 13, the oldest one was 90 (the average age was 53.2. Of these 11 died, representing a mortality rate of 3.2%. Of these 11 patients, 7 suffered from chronic intrathoracal suppuration. 82 patients had chronic empyema. 44 patients (13%) were treated by the open window procedure, 6 females and 38 males. The average age was 62.1. Of them 7 died, the mortality rate of chronic empyema thoracis was 8.5% in our department. Of 164 pus samples taken from suppurative pleura cavity bacteria, Pseudomonas spp., were bred in 148 cases during bacteriological examinations. Their bacteriological examinations confirm that local and aimed treatment by Polimyxin, Amikacin, Meronpenem, Ceftadizim, Imipenem, Tobramycin, Ciprofloxacin and Piperacillin proved to be the better medicine against Pseudomonas infection.

Synthesis and biological activity of a new progestogen, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3, 20-dione acetate

The progestational activity of second- and third-generation progestins in oral contraceptives were markedly increased by addition of an 18-methyl group. A new progestin, the 18-methyl analog of Nestorone, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3,2 0-dione acetate (10), was synthesized. The relative binding affinity and biologic activity of 10 was compared with Nestorone, levonorgestrel, and progesterone using a binding assay for rat progesterone receptors, the Clauberg assay in the rabbit, and by assessing pregnancy maintenance in the rat. These studies, as summarized in Table 4, show that 10 is three to ten times more potent than Nestorone. The addition of the 18-methyl group to Nestorone markedly increased its potency as noted above, but is unlikely to change its rate of delivery from sustained release systems. 10 should be ideally suited for administration by implants or small skin patches.

Effect of 1,25(OH)(2)-vitamin D(3) on the activation of natural killer cells: role of protein kinase C and extracellular calcium

As a first approach for studying the implication of PKC and the steroid hormone 1,25(OH)(2)-vitamin D(3) [1,25(OH)(2)D(3)] on natural killer cell (NK) activity, we analyzed in the YT NK cell line the expression of PKC isoforms and the effects of 1, 25(OH)(2)D(3) on BLT-esterase (a marker of NK lytic granules) activity. Western blot and RT-PCR showed a greater extent of PKC alpha, beta, delta, zeta, epsilon, theta, and lambda and lower levels of PKC mu and eta. In a dose-dependent manner 1, 25(OH)(2)D(3) induced significant increases in BLT-esterase and PKC activities and the stimulatory effect on BLT-esterase activity was mimicked and blocked, respectively, by the PKC activator phorbol ester PMA and PKC inhibitors (H7, PKC(19-36), and N-myristoylated PKC(19-31) peptides). Moreover, the effects of 1,25(OH)(2)D(3) on BLT-esterase could be blocked in a Ca(2+)-free (+EGTA) medium and mimicked by the Ca2+ ionophore A23187. The results suggest that 1, 25(OH)(2)D(3) is a stimulatory factor of NK activity acting through a mechanism involving PKC and extracellular Ca2+.

The role of CT examination in diagnostics and surgery of chronic empyema thoracis

Computer tomography (CT) has become one of the most important modern diagnostic procedure in the detection, differential diagnosis, treatment and the postoperative follow up of patients suffering from chronic intrathoracic suppuration. Although CT examination is nowadays almost unlimitedly available it is still not regarded as a routine diagnostic procedure. It proves to be remarkably useful in the surgical treatment of neglected, chronic cases of suppuration in the thoracic cavity. On the basis of the Moores empyema thoracis classification [3] patients in the third stage belong to the group with chronic intrathoracic suppuration. Their empyema can only be treated by a major surgery or a series of operations.

Chemical models of cytochrome P450 catalyzed insecticide metabolism. Application to the oxidative metabolism of carbamate insecticides

Cytochrome P450 (CP450) catalyzed oxidative metabolism of carbofuran (1), carbaryl (2), and pirimicarb (3) has been modeled using biomimetic oxidations catalyzed by iron(III) tetraarylporphyrins. Oxidation products of 1 were identified by comparison of HPLC retention times measured under standardized conditions for metabolites synthesized and characterized by (1)H and (13)C NMR spectroscopy. Comparison of product distributions to in vivo metabolic profiles revealed that the H(2)O(2)/meso-tetrakis(pentafluorophenyl)porphyrin iron(III) chloride [Fe(TF(20)PP)] system mimics the action of insect CP450s against carbofuran. The effectiveness of this system was further demonstrated by the biomimetic oxidation of other carbamate insecticides (2 and 3) monitored by HPLC/electrospray MS. The predictive power of this biomimetic model was compared to that of knowledge-based expert systems. Although similar models were recently applied in pharmaceutical research, the usefulness of this approach has first been demonstrated for the prediction of metabolic profiles of agrochemicals.

Tube loop (seton) drainage treatment of recurrent extrasphincteric perianal fistulae

Tube loop seton drainage treatment of multiply recurring high-spreading extrasphincteric perianal fistulae in 19 patients is reported in this study. The drainage loop setons make possible the rinsing of the wound following fistulectomy and also the bidirectional drainage of the wound discharge. Strangulation of the wound and an early closure of the fistula and hence the development of recurrence is prevented by means of controlled formation of scarred tissue. The sphincteral musculature of the anus is also protected from damage. Thirty-five recurring fistulae of 19 patients included in the present study were treated successfully by this method. Two fistula recurred. None of these patients developed incontinence. The use of tube loop setons was found to have advantages over the pull-out method in cases of high-spreading multiply recurring extrasphincteric or suprasphincteric perianal fistulae.

[The role of CT examination in the diagnosis and therapy of chronic thoracic empyema]

Successful surgical treatment of chronic intrathoracic suppuration can, in the substantial majority of cases, be accomplished only by means of major surgery or a series of thoracic operations. If a solution to the chronic process cannot be provided by decortication of the lung, or should decortication not be possible due to the moribund condition of the patient, successful treatment can still be achieved through thoracic fenestration. 314 patients were treated for chronic suppuration in the thoracic cavity between 1st January 1987 and 31st December 1997. Of these, ten died, this representing a mortality rate of 3.1%. Seven of these ten patients suffered chronic suppuration. The total number of patients suffering chronic suppuration was 73 (23.2%). Of these 73 patients, in 31 cases treatment involving two or more surgical intervention procedures was performed. Three of the ten patients on whom open surgery was performed died, these having been referred to the department already in a moribund condition. It was decided that prolonged open surgery should be performed on three patients. CT examination enables the position of the empyema, the depth of the callus surrounding it, the position of drains and the relation between the visceral pleura and the pulmonary parenchyma and their demarcation to be determined prior to open surgery with greater precision than by any other diagnostic technique developed previously. CT examination has acquired a fundamental role, subsequent to partial resection or pneumonectomy, in the examination of the bronchial trunk and in the detection of fistulae. Following open surgery CT is also appropriate for the evaluation of the dimensions of the cavity, its form, the depth of granulation tissue, retraction of the bony thoracic structure and the condition of the bronchial stump. Where there is a precedent of tumours it can provide assistance in the detection of recurrence, lymph node conditions or metastasis. Complications arising subsequent to surgery (bronchial fistula, recurrent empyema, etc.) can thus be detected in due time. Prior to thoracoplasty or myoplasty the condition of the myocutaneous lobe twisted on a neurovascular spindle and sealing the cavity can be examined clearly by means of CT, as can the viability of the transposed skin and the muscle fascicle subsequently.

Estimation of impurity profiles of drugs and related materials: part 19: theme with variations. Identification of impurities in 3-oxosteroids

Due to the varied reactions leading to the 3-oxo group in steroids and the reactivity of its environment, a large number of impurities related to this group are formed during the reaction steps and the degradation studies. In this paper the experiences from the authors laboratory with the 3-oxo-related impurities in 19-nor-4-ene-3-oxosteroids (norgestrel, norethisterone, nandrolone, its esters and Nestorone) as well as corticosteroids (prednisolone, mazipredone, etc) are presented. The impurities include saturated 3-ones, 1-ene-3-ones, 5(10)-ene-3-ones, 3-deoxo and 3-ethinyl-3,5-diene derivatives, 6-ene, 8(14)-ene, 6,8(14)-diene, 6-hydroxy (alpha and beta), 10beta-hydroxy and 6-one derivatives in 4-ene-3-oxosteroids and 8(9)-ene, 9(11)-ene, 11alpha-hydroxy, 11-oxo and 4-ene-3-one derivatives in 11beta-hydroxy-1,4-diene-3-oxosteroids. The chromatographic, spectroscopic and hyphenated techniques used in this study include TLC, GC, HPLC with diode array UV detector, GC-MS, LC-MS and NMR methods.

Membrane physical state controls the signaling mechanism of the heat shock response in Synechocystis PCC 6803: identification of hsp17 as a "fluidity gene"

The fluidity of Synechocystis membranes was adjusted in vivo by temperature acclimation, addition of fluidizer agent benzyl alcohol, or catalytic lipid hydrogenation specific to plasma membranes. The reduced membrane physical order in thylakoids obtained by either downshifting growth temperature or administration of benzyl alcohol was paralleled with enhanced thermosensitivity of the photosynthetic membrane. Simultaneously, the stress-sensing system leading to the cellular heat shock (HS) response also has been altered. There was a close correlation between thylakoid fluidity levels, monitored by steady-state 1,6-diphenyl-1,3,5-hexatriene anisotropy, and threshold temperatures required for maximal activation of all of the HS-inducible genes investigated, including dnaK, groESL, cpn60, and hsp17. The causal relationship between the pre-existing thylakoid physical order and temperature set point of both the transcriptional activation and the de novo protein synthesis was the most striking for the 17-kDa HS protein (HSP17) associated mostly with the thylakoid membranes. These findings together with the fact that the in vivo modulation of lipid saturation within cytoplasmic membrane had no effect on HS response suggest that thylakoid acts as a cellular thermometer where thermal stress is sensed and transduced into a cellular signal leading to the activation of HS genes.

[Incidence of septal aneurysm and its clinical significance]

The authors performed 451 transesophageal echocardiographic (TEE) investigations over a period of three years and four months. Atrial septal aneurysm (ASA) was found in 40 cases. Of these, protrusion of the atrial septum towards the right atrium was observed in 17 cases, whilst oscillation of the atrial septum was noted in 23 cases. ASA was associated with patent foramen ovale (PFO) in ten patients, with type II. ASD in nine patients, with other congenital heart disease in six patients, and with other organic heart disease in eight patients. In three cases either an embolus or a tumor was detected in the left atrium, whilst in four cases with ASA there were no other organic cardiac disorders found. In ten patients there was a history of cerebral embolisation. Of these two had chronic atrial fibrillation, whilst the others had sinusrhythm. Of those who had cerebral embolisation, four patients had PFO, one patient had left atrial and auricular thrombi, whilst in four patients various organic heart problems (ischemic heart disease, left ventricular hypertrophy) were detected. In one patient with ASA there was no other cardiac abnormality detected. The authors conclude that ASA, which is often associated with PFO and ASD (in 25.0% and 22.5% of their cases, respectively) is detected in around eight percent of the patients who undergo TEE. ASA particularly when associated with PFO should be considered as a potential source of cerebral emboli. Indeed, cerebral embolisation occurred in 25% of their patients with ASA. It is recommended, that patients with ASA are treated with acetyl salicylic acid, whilst in patients with ASA and PFO anticoagulant therapy is the treatment of choice. In case of cerebral embolisation, or repeated cerebral ischemic attacks, operative interventions should be considered.

[Mycoplasma pneumoniae epidemic as zoonosis]

At a secondary school in Budapest, in the first class, 30 students became sick with fever and upper respiratory catarrhal symptoms between September 19 and October 31, 1995. Two children were hospitalized with a diagnosis of pneumonia, in case of the two children treated at the Szent László Hospital, suspect of Mycoplasma infection raised which was also confirmed by cold agglutination test. During the epizootiological examination on the spot they found a terrarium in the classroom where the students raised a Syrian gold hamster family. Mycoplasmas were isolated from the lung samples of the hamsters during the pathological examination which proved to be Mycoplasma pneumoniae. Owing to the close etiologic relationships between epidemiological anamnesis, characteristics of the epidemic, as well as findings of patients and pathological or histological findings in the hamsters together with the results of bacteriological examinations, the epidemic should be considered as a zoonosis.

Bimoclomol: a nontoxic, hydroxylamine derivative with stress protein-inducing activity and cytoprotective effects

Preservation of the chemical architecture of a cell or of an organism under changing and perhaps stressful conditions is termed homeostasis. An integral feature of homeostasis is the rapid expression of genes whose products are specifically dedicated to protect cellular functions against stress. One of the best known mechanisms protecting cells from various stresses is the heat-shock response which results in the induction of the synthesis of heat-shock proteins (HSPs or stress proteins). A large body of information supports that stress proteins--many of them molecular chaperones--are crucial for the maintenance of cell integrity during normal growth as well as during pathophysiological conditions, and thus can be considered "homeostatic proteins." Recently emphasis is being placed on the potential use of these proteins in preventing and/or treating diseases. Therefore, it would be of great therapeutic benefit to discover compounds that are clinically safe yet able to induce the accumulation of HSPs in patients with chronic disorders such as diabetes mellitus, heart disease or kidney failure. Here we show that a novel cytoprotective hydroxylamine derivative, [2-hydroxy-3-(1-piperidinyl) propoxy]-3-pyridinecarboximidoil-chloride maleate, Bimoclomol, facilitates the formation of chaperone molecules in eukaryotic cells by inducing or amplifying expression of heat-shock genes. The cytoprotective effects observed under several experimental conditions, including a murine model of ischemia and wound healing in the diabetic rat, are likely mediated by the coordinate expression of all major HSPs. This nontoxic drug, which is under Phase II clinical trials, has enormous potential therapeutic applications.

Drug impurity profiling strategies

A general scheme is set up for the estimation of the impurity profile of bulk drug substances by the complex use of chromatographic, spectroscopic and hyphenated techniques. Several examples are presented as illustrations to the scheme from the authors' laboratory involving the use of chromatographic methods such as thin-layer-(TLC), gas-(GC), analytical and preparative high-performance liquid chromatography (HPLC), spectroscopic methods such as mass spectrometry (MS) and NMR spectroscopy as well as hyphenated techniques (HPLC/diode-array UV, GC/MS and HPLC/MS). In addition to summarizing earlier work, new examples are also presented: identification of an impurity (propyl 4-[diethylcarbamoyl(methoxy)]-3-methoxy phenylglyoxylate, II) in propanidid (I) and two unsaturated impurities in allylstrenol (VII) by GC/MS and HPLC/diode-array UV as well as estimation of the impurity profile of mazipredone (III) by HPLC/MS and HPLC/diode-array UV.

Modulation of lipid unsaturation and membrane fluid state in mammalian cells by stable transformation with the delta9-desaturase gene of Saccharomyces cerevisiae

The composition and physical state of membrane lipids determine the dynamic nature of membranes, which in turn, could directly be linked to the activity of various membrane-associated cellular functions. To better understand the molecular basis of different membrane-related phenomena we established a novel strategy to alter unsaturation of mammalian cell membranes with an identical genetic background. We transfected L929 mouse fibroblastoid cells with DNA constructs containing the Delta9-fatty acid desaturase gene (Ole1) of S. cerevisiae under the control of desaturase promoters derived either from wild type or mutant strains of the dimorphic fungus H. capsulatum.

Estimation of impurity profiles of drugs and related materials. Part 16: Identification of the side-products of the ethinylation step in the synthesis of contraceptive gestogens

A new apolar impurity (3,17 alpha-diethinyl-13-ethyl-3,5-gonadiene-17-ol, IIb) was detected and identified in norgestrel with the aid of thin-layer and high-performance chromatography and spectroscopic techniques. IIb is the product of the acid-catalysed dehydration of an overethinylated side product (Ib) of the ethinylation step in the synthesis of norgestrel. IIb can be determined by thin-layer densitometry and high-performance liquid chromatography. Another impurity (17 alpha-ethinyl-13-ethyl-4-gonene-17-ol, IV), originating from a side product of the Birch reduction step in the synthesis of norgestrel was also detected and identified. The spot of IV overlaps with that of IIb in the TLC system of USP XXIII but can be separated and quantification by more selective TLC systems and by gas chromatography.

Influence of age on 1,25(OH)2-vitamin D3 activation of protein kinase C in rat duodenum

We have studied age-related changes in the non-genomic regulation of protein kinase C (PKC) by 1,25-dihydroxy-vitamin D3 [1,25(OH)2D3] and their role in 1,25(OH)2D3-dependent calcium uptake in the rat duodenum. Treatment of duodenal mucosae from 3 month-old (young) rats with hormone physiological concentrations (0.1 nM) induced an acute and transient stimulation of total tissue PKC activity which was maximal at 1 min (+80%). The responses were evidenced up to 10 nM 1,25(OH)2D3. The duodenum from 22 to 24 month old (aged) rats exhibited higher basal PKC activity which was not significantly modified after addition of the hormone. In the young duodenum PKC activation by 1,25(OH)2D3 was dependent on extracellular Ca2+ influx as it could be abolished to a great extent by EGTA and the Ca2+ channel blocker verapamil. In addition, the Ca2+ ionophore A23187 elicited a marked stimulation of duodenal mucosae PKC in young rats but was without effects in aged animals. 1,25(OH)2D3 increased the influx of 45Ca2+ in duodenal mucosae of young rats in a dose-(0.1-1 nM) and time-(1-10 min) dependent fashion. This response to the hormone was impaired in aged animals. Similarly as 1,25(OH)2D3, the PKC activator dioctanoylglycerol (DOG) rapidly (1-5 min) increased [45Ca2+] influx in duodena from young rats whereas the response to DOG was blunted in senescent animals. Furthermore, PKC inhibitors (bisindolylmaleimide, staurosporine and compound H7) abolished 1,25(OH)2D3 stimulation of Ca2+ uptake in the young duodenum. These results suggest that 1,25(OH)2D3 regulates PKC activity in the mammalian duodenum by a non-genomic mechanism which involves the rapid influx of extracellular Ca2+, and that activation of PKC, in turn, mediates hormone stimulation of intestinal Ca2+ uptake. The data also indicates that 1,25(OH)2D3 regulation of Ca2+ transport through the PKC messenger system is impaired with aging.

Evidence for a lipochaperonin: association of active protein-folding GroESL oligomers with lipids can stabilize membranes under heat shock conditions

During heat shock, structural changes in proteins and membranes may lead to cell death. While GroE and other chaperone proteins are involved in the prevention of stress-induced protein aggregation and in the recovery of protein structures, a mechanism for short-term membrane stabilization during stress remains to be established. We found that GroEL chaperonin can associate with model lipid membranes. Binding was apparently governed by the composition and the physical state of the host bilayer. Limited proteolysis of GroEL oligomers by proteinase K, which removes selectively the conserved glycine- and methionine-rich C terminus, leaving the chaperonin oligomer intact, prevented chaperonin association with lipid membranes. GroEL increased the lipid order in the liquid crystalline state, yet remained functional as a protein-folding chaperonin. This suggests that, during stress, chaperonins can assume the functions of assisting the folding of both soluble and membrane-associated proteins while concomitantly stabilizing lipid membranes.

[The frequency of left atrial spontaneous echo contrast and its clinical significance in mitral valve insufficiency]

The authors investigated the frequency of left atrial spontaneous echo contrast in mitral valve disease. They also tested whether there was any correlation between the presence of left atrial spontaneous echo contrast and the severity of the mitral valve disease. Echocardiographic investigations were performed using both transthoracal and transesophageal echocardiographic methods employing monoplane transducer. The authors carried out 273 transesophageal investigations over a period of 2 years and found left atrial spontaneous echo contrast in 85 patients, who had mitral valve disease. Of this, in 18 cases thrombi were also detected in the left atrium and/or auricula. The diagnoses of mitral stenosis were made in 24 patients, of whom in 12 cases the stenosis were found to be severe, whilst in 12 cases to be moderate. Furthermore insufficiency of the mitral valve was detected in 35 cases. 20 patients had artificial mitral valve implanted, they received long term anticoagulant treatment. 59 patients had no spontaneous echo contrast. 14 patients had previous embolic events of which 9 were cerebral and in other cases arteries of the kidney, eye and extremities were affected. 71 patients had no history of embolism. The authors concluded that mitral valve disease, particularly mitral stenosis is frequently associated with left atrial spontaneous echo contrast. It has been also observed, that the more severe the mitral valve disease, the greater the probability of left atrial spontaneous echo contrast. In all cases where thrombi were found, left atrial echo contrast were demonstrated and the risk of embolism is high. In these cases anticoagulant therapy is suggested.

[Central bronchoplastic procedures in Hungary and their outcome (198-1993)]

Bronchoplastic procedures involving the main carina are declared as central bronchoplasties. A nation-wide collection of these interventions performed between 1980 and 1993 is analysed. The study is on a total of 154 operations, that were 16 bifurcation resections and 14 stem bronchus resections without parenchyma sacrifice, 61 sleeve or wedge pneumonectomies and 63 tracheal sleeve or wedge right upper lobectomies or carina-plasties. Surgery alone-without multimodality therapy-was the choice of treatment almost exclusively. About 90% of these interventions were performed for highly malignant, histologically peripheral-type, but centrally located bronchial cancers. The hospital mortality and morbidity were found up to 30% (an average of appr. 17%), depending on surgical subsets. Cause of death were surgical at 11% (leakage, anastomotic dehiscence and bleeding) and non surgical at 5.8% respectively. Complications at another 9% were related to surgery. Data of survival suggest, that nodal state is the strongest predictor, but the unfavourable N2 group comprises longer survivors as well. Certain part of this kind of interventions is to be chosen without alternatives (isolated tracheobronchial resections without parenchyma-resection, extended pneumonectomies) while extended lobectomies are alternatives of the extended pneumonectomies in strict conditions. A central bronchoplastic procedure is justified only with hope of complete resection for its high complication rate.

Age-associated decrease in inositol 1,4,5-trisphosphate and diacylglycerol generation by 1,25(OH)2-vitamin D3 in rat intestine

The hormonal form of vitamin D3, 1,25(OH)2-vitamin D3(1,25[OH]2D3), stimulates the breakdown of membrane phosphoinositides, generating inositol-1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) in a variety of cell systems. Several studies suggest that alterations in the receptor-mediated phosphoinositide cascade are involved in the pathophysiology of aging. Therefore, the formation of IP3 and DAG were determined under basal conditions and after stimulation with physiological concentrations of 1,25(OH)2D3 in duodenum from young (3-mo-old) and aged (24-mo-old) rats. The hormone induced a transient and biphasic formation of IP3 and DAG. Values obtained in young rats peaking at 15 s (51% and 42% above basal levels for IP3 and DAG, respectively) and at 3 min (90% and 74% above basal levels for IP3 and DAG, respectively) were significantly decreased in duodenum from senescent animals (IP3: +20% and DAG: +18% above basal level at 15 s; and IP3: +18% and DAG: +29% above basal level at 3 min). The 1,25(OH)2D3-induced generation of DAG in both young and aged duodenum was effectively inhibited in the presence of neomycin, a phospholipase C (PLC) inhibitor, and was dependent on extracellular Ca2+. After the biphasic response, the levels of DAG generated by the hormone (10 min stimulation) remained elevated; the elevation occurred in the absence of IP3 production; and the elevated levels were not abolished by neomycin, implying that phospholipids other than phosphoinositides are the source of DAG. This 1,25(OH)2D3-dependent late phase of DAG generation was also diminished in aged animals. The precise molecular basis and the physiological significance of decreased liberation of IP3 and DAG by 1,25(OH)2D3 in the aged rat duodenum remains to be determined.

Estimation of impurity profiles of drugs and related materials. 12. Isolation and identification of an isomeric impurity in danazol

We report on a new isomeric impurity of danazol. This impurity designated as isodanazol was detected by reversed-phase high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Its structure was determined after separation by preparative HPLC. Mass spectrometry revealed the isomeric nature of the impurity while the UV spectrum indicated profound difference in the isoxazole moieties. The structure of the isomeric isoxazole ring in isodanazol was determined by NMR spectroscopy using COSY, HETCOR and NOE measurements. The difference between the UV spectra of danazol and isodanazol is explained on the basis of the difference between the aromaticities of their isoxazole rings supported by quantum chemical calculations. The quantitative determination of the impurity down to the 0.05% level can be performed by HPLC, gas chromatography and TLC densitometry.

["Loop"-drainage in the management of recurrent extra-sphincteric perianal fistulae]

This work covers the loop seton drainage tube treatment of multiply recurring high-spreading extrasphincteric perianal fistulas in 14 patients. The drainage loop setons make possible the rinsing of the wound after fistulectomy and bi-directional drainage of the wound discharge. Strangulation of the wound, and hence the development of recurrence, is prevented by means of controlled formation of scar tissue. The sphincteral musculature of the anus is protected from damage. 25 fistulas which recurred in the 14 patients were treated successfully by this method. None of the patients developed incontinence. 1 fistula recurred. With regard to the pull-out method, in the case of high-spreading multiply recurring extrasphincteric or suprasphincteric perianal fistulas.

Estimation of impurity profiles in drugs and related materials. Part 11--The role of chromatographic and spectroscopic methods in the estimation of side-reactions in drug syntheses

Impurities in drugs are classified on the basis of the types of side-reactions in drug syntheses resulting in their formation. This is shown by summarizing the authors' earlier results in the field of impurity profiling of 19-nor-steroids, ethynodiol diacetate, mazipredone, pipecuronium bromide, flumecinol, enalapril, pyridinol carbamate, phenylbutazone, thymotrinan and some new results related to danazol and famotidine.

[Preventive measures for early and late locomotor complications from thoracoplasty and myoplasty]

Two basic methods of prevention of early- and late-occurring complications after thoracoplastic and myoplastic surgery are defined by the authors: I. The function protective surgical method and technique: by the retention of rib 1, the extramuscular periosteal thoracoplastic surgery, resection of as few ribs as possible, total performance of thoracoplastic and myoplastic surgery, epidural assuaging of pain. II. Perioperative physiotherapy and correct rehabilitative treatment, where gymnastics plays the most important role, and also combined application of the different special methods of physiotherapy, can also contribute to favourable results. 17 patients data have been processed and set out in the report. They show the efficiency of the applied methods. Planned and purposeful co-operation between the surgeon and the physiotherapist is needed in the medical treatment of patients.

[Excerpts from the investigations of pipecuronium bromide with NMR spectroscopy]

The synthesis of Pipecuronium bromide together with the investigation of its impurity profile required the solution of a number of analytical and structural problems. NMR spectroscopical methods received a major role in the structure elucidation of the synthesized compounds. The quantitative assessment of contaminations was also realized by 1H NMR spectroscopy. Out of the large amount of undertaken investigations, here we provide the structural characterization of the contaminating regiosimers of an important intermediate (5 alpha-androst-2-en-17-on) formed in the course of the synthesis, together with the NMR signal assignments of the end-product (Pipecuronium bromide) as measured in D2O and a mixture of CDCl3/DMSO-d6. The structure of a minor contamination of the end-product is also given.

[Current treatment of thoracic empyema in adults]

Experiences obtained with 400 cases of thoracal empyema are described. The fact that the rate of lethality was 18.7% until present points out to the severity of the disease. The semi-conservative therapeutical methods used by the author (drainage, drainage and pleura lavage, pleura lavage and thoracoscopy, balance drainage) are presented. With their sensibly more frequent use the rate of operation could be reduced by 8% (from 36.5% to 28.5%) and the lethality rate by 7.6% (from 18.7% to 11.1). Further improvement of the results may be expected of the increased number of early detection (basic care), concentration of empyemic patients in special institutes (departments, wards) and due to it of a more efficient special treatment of uniform contemplation.

[Analysis of steroids. Part 42. By-products of the ethynylation of 17-ketosteroids (isolation, identification and determination)]

The therapeutically very important 17 alpha-ethynyl steroids are prepared from 17-keto steroids by means of addition of acetylene. Two important side reactions of this procedure are known: the formation of the isomeric beta-ethynyl derivative and the formation of a dimeric product with acetylene bridge. The aim of this paper is to approach this problem from the point of view of impurity profiling of 17 alpha-ethynyl steroids (norethisterone, ethisterone, norgestrel and delta 9(11)-ethisterone) i.e. isolation, identification and quantification of the above mentioned by-products as impurities in the bulk drugs. Capillary gas chromatography is an ideal tool for the separation and quantitative determination of the beta-ethynyl derivatives (20 m long fused silica capillary, I.D 0.2 mm; stationary phase Ultra-2: 5% phenylmethyl silicon gum phase with a film thickness of 0.33 mu; column temperature 240-250 degrees C). The dimeric impurity cannot be determined directly by gas chromatography as it decomposes in the flash heater to the 17 alpha-ethynyl and the 17-keto derivatives. For this reason reversed-phase HPLC was preferred for their separation and quantitation; (column: 250 x 4 mm LiChrosorb RP-18, 10 microns; eluent methanol-water 7:3; UV detector 240 nm). The HPLC method is suitable for the separation and determination of the beta-ethynyl impurities, too. The chemical shifts of the protons and carbon atoms in the vicinity of C-17 in the 1H and 13C NMR spectra of the epimeric 17-ethynyl steroids greatly depend on the configuration of the ethynyl group and for this reason they (especially that of the C-18 are eminently suitable for the characterization of the isomers.(ABSTRACT TRUNCATED AT 250 WORDS)

[Analysis of steroids. Part 40. Isolation and identification of unusual impurities in ethynodiol diacetate]

In the course of the estimation of the impurity profile of ethynodiol diacetate, in addition to common impurities such as norethisterone acetate, ethynodiol-3-acetate and alpha-ethynodiol diacetate, two unknown impurities were detected by analytical reversed phase HPLC (C-18 silica and 80% aq. methanol as the eluent) and isolated by normal phase preparative HPLC (silica and 98:2 mixture of hexane and 2-propanol as the eluent). The 1H- and 13C-NMR spectra of the isolated impurities revealed that their structures could be characterized as the E and Z isomers of an analogue of EDDA containing "trimerised acetyl" group at the 17-hydroxy group (structures 4 and 4a). These structures were in good agreement with the extended UV spectra of the impurities and the mass spectra with the m/z 438 peak which can be derived from 4 and 4a by the loss of ketene.

Estimation of impurity profiles of drugs and related materials. Part VIII: Combined application of high-performance liquid chromatography and NMR spectroscopy in the impurity profiling of drugs

The usefulness of the joint application of HPLC and NMR spectroscopy in drug impurity profiling is demonstrated by the following examples: (1) identification of Z and E isomers of 17 alpha-ethynyl-4-oestrene-3 beta, 17-diol-3-acetate-17-(3'-acetoxy-2'-butenoate) in ethynodiol diacetate; (2) identification of the p-tolyl analogue as the impurity of enalapril maleate; (3) identification and quantification of 2'-dehydro-pipecuronium bromide in pipecuronium bromide. The possibilities of utilizing NMR spectroscopy for the identification and quantification of the impurities with and without their isolation are discussed.