Hemorrhagic cystitis following allogeneic hematopoietic stem cell transplantation: experience in a pediatric oncological institution. / Cistitis hemorrágica tras trasplante alogénico de progenitores hematopoyéticos: experiencia en un centro oncológico pediátrico.

OBJECTIVE: To analyze the risk factors associated with hemorrhagic cystitis (HC) severity and the treatment strategies available in HC patients following allogeneic hematopoietic stem cell transplantation (AHSCT). MATERIALS AND METHODS: A retrospective study of medical records was carried out. Patients with HC following AHSCT treated from 2017 to 2021 were divided into two groups according to severity -mild and severe. Demographic data, disease-specific characteristics, urological sequelae, and overall mortality were compared between both groups. The hospital's protocol was used for patient management. RESULTS: 33 episodes of HC were collected in 27 patients, 72.7% of whom were male. HC incidence following AHSCT was 23.4% (33/141). 51.5% of HCs were severe (grades III-IV). Severe graft host disease (GHD) (grades III-IV) and thrombopenia at HC onset were associated with severe HC (p= 0.043 and p= 0.039, respectively). This group had longer hematuria times (p< 0.001) and required more platelet transfusions (p= 0.003). In addition, 70.6% required bladder catheterization, but only 1 case needed percutaneous cystostomy. None of the patients with mild HC required catheterization. No differences were found in terms of urological sequelae or overall mortality. CONCLUSIONS: Severe HC could be predicted thanks to the presence of severe GHD or thrombopenia at HC onset. Severe HC can be managed with bladder catheterization in most of these patients. A standardized protocol may help reduce the need for invasive procedures in patients with mild HC.

OBJETIVO: Analizar factores de riesgo asociados a la gravedad de la cistitis hemorrágica (CH) y estrategias de tratamiento en pacientes con CH tras trasplante alogénico de progenitores hematopoyéticos (TAPH). MATERIAL Y METODOS: Estudio retrospectivo de historias clínicas. Los pacientes con CH tras TAPH tratados entre 2017 y 2021 se dividieron en dos grupos según la gravedad del cuadro (leve y grave). Se compararon datos demográficos, características específicas de la enfermedad, secuelas urológicas y mortalidad global entre ambos grupos. Se utilizó el protocolo del hospital para el manejo de los pacientes. RESULTADOS: Se recogieron 33 episodios de CH en 27 pacientes, de los cuales el 72,7% fueron varones. La incidencia de CH tras TAPH fue del 23,4% (33/141). El 51,5% de las CH fueron graves (grados III-IV). La enfermedad de injerto contra huésped (EICH) grave (grados III-IV) y la trombopenia al inicio se asociaron a CH grave (p= 0,043 y p= 0,039, respectivamente). Este grupo tuvo mayor tiempo de hematuria (p< 0,001) y necesitó más transfusiones de plaquetas (p= 0,003). Además, el 70,6% precisó sondaje vesical, pero solo un caso cistostomía percutánea. Ningún paciente con CH leve precisó sondaje. No hubo diferencias en las secuelas urológicas ni en la mortalidad global. CONCLUSIONES: Una CH más grave podría predecirse por la presencia de EICH grave o trombopenia al inicio del cuadro. La CH grave puede manejarse con sondaje vesical en la mayoría de estos pacientes. Seguir un protocolo estandarizado puede reducir la necesidad de procedimientos invasivos en pacientes con CH leve.

Prognostic factors at admission on patients with cancer and COVID-19: Analysis of HOPE registry data.

BACKGROUND: Previous works seem to agree in the higher mortality of cancer patients with COVID-19. Identifying potential prognostic factors upon admission could help identify patients with a poor prognosis. METHODS: We aimed to explore the characteristics and evolution of COVID-19 cancer patients admitted to hospital in a multicenter international registry (HOPE COVID-19).Our primary objective is to define those characteristics that allow us to identify cancer patients with a worse prognosis (mortality within 30 days after the diagnosis of COVID-19). RESULTS: 5838 patients have been collected in this registry, of whom 770 had cancer among their antecedents. In hospital mortality reached 258 patients (33.51%). The median was 75 years (65-82). Regarding the distribution by sex, 34.55% of the patients (266/770) were women.The distribution by type of cancer: genitourinary 238/745 (31.95%), digestive 124/745 (16.54%), hematologic 95/745 (12.75%).In multivariate regression analysis, factors that are independently associated with mortality at admission are: renal impairment (OR 3.45, CI 97.5% 1.85-6.58), heart disease (2.32, 1.47-3.66), liver disease (4.69, 1.94-11.62), partial dependence (2.41, 1.34-4.33), total dependence (7.21, 2.60-21.82), fatigue (1.84, 1.16-2.93), arthromialgias (0.45, 0.26-0.78), SatO2 < 92% (4.58, 2.97-7.17), elevated LDH (2.61, 1.51-4.69) and abnormal decreased Blood Pressure (3.57, 1.81-7.15). Analitical parameters are also significant altered. CONCLUSION: In patients with cancer from the HOPE registry, 30-day mortality from any cause is high and is associated with easily identifiable clinical factors upon arrival at the hospital. Identifying these patients can help initiate more intensive treatments from the start and evaluate the prognosis of these patients.

ANTECEDENTES: Trabajos previos parecen coincidir en la mayor mortalidad de los pacientes con cáncer y COVID-19. La identificación de posibles factores pronósticos en el momento del ingreso podría ayudar a identificar a los pacientes con mal pronóstico. MÉTODOS: Nos propusimos explorar las características y la evolución de los pacientes con cáncer y COVID-19 ingresados en un registro internacional multicéntrico (HOPE COVID-19).Nuestro objetivo principal es definir aquellas características que nos permitan identificar a los pacientes con cáncer de peor pronóstico (mortalidad en los 30 días siguientes al diagnóstico de COVID-19). RESULTADOS: En este registro se ha recogido a 5.838 pacientes, de los cuales 770 tenían cáncer entre sus antecedentes. La mortalidad hospitalaria alcanzó a 258 pacientes (33,51%). La mediana fue de 75 años (65-82). En cuanto a la distribución por sexo, el 34,55% de los pacientes eran mujeres (266/770).La distribución por tipo de cáncer: genitourinario 238/745 (31,95%), digestivo 124/745 (16,54%) y hematológico 95/745 (12,75%).En el análisis de regresión multivariante, los factores que se asocian de forma independiente con la mortalidad al ingreso son: insuficiencia renal (OR 3,45; IC 97,5%: 1,85-6,58), cardiopatía (2,32; 1,47-3,66), hepatopatía (4,69; 1,94-11,62), dependencia parcial (2,41; 1,34-4,33), dependencia total (7,21; 2,60-21,82), fatiga (1,84, 1;16-2,93), artromialgias (0,45; 0,26-0,78), SatO2 < 92% (4,58; 2,97-7,17), LDH elevada (2,61; 1,51-4,69) y disminución anormal de la presión arterial (3,57; 1,81-7,15). Los parámetros analíticos también están significativamente alterados. CONCLUSIÓN: En los pacientes con cáncer del registro HOPE, la mortalidad a los 30 días por cualquier causa es elevada y se asocia a factores clínicos fácilmente identificables a su llegada al hospital. La identificación de estos pacientes puede ayudar a iniciar tratamientos más intensivos desde el principio y evaluar el pronóstico de estos pacientes.

Prognostic factors at admission on patients with cancer and COVID-19: Analysis of HOPE registry data.

BACKGROUND: Previous works seem to agree in the higher mortality of cancer patients with COVID-19. Identifying potential prognostic factors upon admission could help identify patients with a poor prognosis. METHODS: We aimed to explore the characteristics and evolution of COVID-19 cancer patients admitted to hospital in a multicenter international registry (HOPE COVID-19). Our primary objective is to define those characteristics that allow us to identify cancer patients with a worse prognosis (mortality within 30 days after the diagnosis of COVID-19). RESULTS: 5838 patients have been collected in this registry, of whom 770 had cancer among their antecedents. In hospital mortality reached 258 patients (33.51%). The median was 75 years (65-82). Regarding the distribution by sex, 34.55% of the patients (266/770) were women. The distribution by type of cancer: genitourinary 238/745 (31.95%), digestive 124/745 (16.54%), hematologic 95/745 (12.75%). In multivariate regression analysis, factors that are independently associated with mortality at admission are: renal impairment (OR 3.45, CI 97.5% 1.85-6.58), heart disease (2.32, 1.47-3.66), liver disease (4.69, 1.94-11.62), partial dependence (2.41, 1.34-4.33), total dependence (7.21, 2.60-21.82), fatigue (1.84, 1.16-2.93), arthromialgias (0.45, 0.26-0.78), SatO2<92% (4.58, 2.97-7.17), elevated LDH (2.61, 1.51-4.69) and abnormal decreased Blood Pressure (3.57, 1.81-7.15). Analitical parameters are also significant altered. CONCLUSION: In patients with cancer from the HOPE registry, 30-day mortality from any cause is high and is associated with easily identifiable clinical factors upon arrival at the hospital. Identifying these patients can help initiate more intensive treatments from the start and evaluate the prognosis of these patients.

Aneurysm of the anterior leaflet of the mitral valve secondary to aortic valve endocarditis.

Aneurysm of the anterior mitral leaflet is a rare complication of infective aortic valve endocarditis, the natural evolution of which is generally its rupture, with subsequent acute and severe mitral regurgitation. Its presence cannot be recognized with transthoracic echocardiography and even in surgery. We describe a 78-year-old man with aortic valve endocarditis, in whom transesophageal echocardiography was essential for the diagnosis of this complication, its therapeutic management, and the postoperative follow-up after simple valve repair. In addition, the most appropriate surgical approach is discussed.

New aromatic iminoimidazolidine derivatives as alpha1-adrenoceptor antagonists: a novel synthetic approach and pharmacological activity.

The design, synthesis and alpha1-adrenoceptor antagonism of a series of bis-imidazoline (1a, 2a, 3a and 4a) and bis-guanidine (1b, 2b, 3b and 4b) diphenyl derivatives are reported. All of these compounds fulfill the conditions of the most recent pharmacophore proposed for alpha1-adrenoceptors and found in the literature. Besides, a novel synthetic approach to the preparation of 2-(arylimino)imidazolidine derivatives is described. All the tested compounds, except the bis-guanidinium derivative 3b, inhibit the contractile responses induced by noradrenaline in aortic rings of rat and rabbit in a dose-dependent manner. Our results indicate that, even though some discrepancies are observed in terms of the alpha1 subtype targeted by this new family of compounds, they show an interesting profile as antagonists of alpha1-adrenoceptors and a new prototype, compound 1a, has been found deserving further development.

[A comparison of the clinical and angiographic evolution of diabetic and nondiabetic patients treated by conventional angioplasty versus stent implantation in native coronary arteries]. / Comparación de la evolución clínica y angiográfica de pacientes diabéticos y no diabéticos tratados con angioplastia convencional frente a implantación de stent en arterias coronarias nativas.

INTRODUCTION AND OBJECTIVES: Diabetic patients have a high restenosis risk after balloon coronary angioplasty. Stent implantation in these patients appears to be a potential beneficial therapeutic option. The aim of this study was to compare the clinical and angiographic outcome of diabetic patients vs non-diabetic patients, treated with conventional angioplasty vs stent implantation in lesions located in native coronary arteries. MATERIAL AND METHODS: A total of 302 patients (58 diabetics and 244 non-diabetics) underwent a coronary angioplasty of one vessel in native coronary arteries with initial success and after at least six months clinical and angiographic follow-up were included in the study. Of the total number of patients, 100 were treated with conventional balloon angioplasty and 202 with stent implantation. Major adverse clinical events and angiographic restenosis rate were evaluated at follow-up. RESULTS: Mean age of patients was 65 years and 74% were male. Angiographic restenosis rate was similar in diabetic vs non-diabetic patients with stent implantation (24% vs 23% respectively). Nevertheless, diabetic patients treated with balloon angioplasty compared to diabetic patients treated with stenting, evolved with a higher restenosis rate (64% vs 24%; p < 0.05), and at the end of follow-up diabetics had need a higher rate of target vessel revascularization (40% vs 24%; p < 0.05), a lower major event free survival (56% vs 70%; p < 0.05) and worse symptomatic status (72% vs 36%; p < 0.05). CONCLUSIONS: Diabetic patients treated with conventional one vessel coronary balloon angioplasty evolved with a high restenosis rate and a bad mid-term clinical outcome. Stent implantation was able reduce to the restenosis rate and improve the mid-term clinical outcome, in a comparable population of diabetic patients.

[The predictive factors of intra-stent restenosis]. / Factores predictores de reestenosis intra-stent.

INTRODUCTION AND OBJECTIVE: Stenting has contributed to improve the early angiographic result, the restenosis rate and the problem of acute and subacute coronary occlusion. In spite of this, the restenosis phenomenon still remains a problem to be completely solved. The aim of the study was to identify clinical, angiographical and procedural factors that are predictive of in-stent restenosis after successful implantation of coronary stent. MATERIAL AND METHODS: We retrospectively analyzed 202 lesions, in 176 consecutive patients who underwent stent implantation with success in our hospital between January 1995 and August 1998. All patients had a clinical follow-up and an angiography after six months of stent implantation. RESULTS: From 202 lesions evaluated, 47 evolved with restenosis (23%). The only independent predictive variables were: to be receiving hypolipemiant treatment before stenting (OR: 0.3; IC: 0.1-0.8), the use of high pressure for stent implantation (OR: 0.4; IC: 0.2-0.9), to implant stent in < 3.1 mm (OR: 2.2; IC: 1.1-4.5) and to have a residual stenosis > 30% after stenting (OR: 13; IC: 1.5-120). CONCLUSIONS: The only statistical variables associated with in-stent restenosis phenomenon were: be under hypolipemiant treatment before the procedure and the use of high pressures for stent implantation; while risk factors arose: to implant stent in vessels < 3.1 mm and suboptimal angiography result after stenting.

Similarity studies on guanidinium, imidazolinium, and imidazolium cations: toward new bradykinin antagonists.

Bradykinin (BK) is a potent nociceptive agent and its antagonists show analgesic activity. In the search for new antagonists of BK, the design of nonpeptidic derivatives with different terminal cations has been considered. Among these new antagonists, the guanidinium cations, which appear not only in the terminal arginine residues of BK but also in several nonpeptidic antagonists, will be substituted by groups with characteristics similar in terms of electrostatic potential, electron density, shape, etc. Several similarity indexes have been calculated for guanidinium, 2-aminoimidazolinium, and 2-aminoimidazolium cations and their corresponding neutral species to design new nonpeptidic BK antagonists. The geometric and electronic characteristics of the molecules were compared by means of: (1) the Carbo index, (2) the Hodgkin index, and (3) a shape similarity index based on the volume of each molecule as defined by a certain electron density. Molecular geometries and energies were optimized by ab initio calculations at the B3LYP/6311+2G** level. The molecular electrostatic potential (MEP) and the electron density (rho) were then computed in a cubic grid of points around each molecule. These molecular properties were used to calculate similarity indexes with the guanidinium cation or guanidine as the reference molecule in each family. In addition, three-dimensional similarity maps were generated to localize those molecular areas more alike in each of the sets.

Molecular modeling of (E)-1-alkyl-4(3)-[2-(1H-azolyl)vinyl]-pyridinium salts and evaluation of their behavior towards choline acetyltransferase.

A new type of extended pi-system aza-analogue of (E)-4-[2-(1-naphthylvinyl)]-1-substituted pyridinium salts (NVP+) has been designed and its inhibitory activity towards choline acetyltransferase (ChAT) has been evaluated in vitro. Among the several examples of the title quaternary salts synthesized 2 and 3, the indolylvinylpyridinium salt 2e is the only one to show a very low ChAT inhibition. The molecular modeling study is highly illustrative of their behavior towards ChAT and interaction with the recognition site. Thus, several selected cations together with the reference NVP+ compound 1a were studied at the PM3 and AM1 levels respectively. At the global minima, all the compounds are planar, which, from the electron charge distribution, shows a degree of polarization similar to the NVP+ model compound 1a. However, the fitting of all optimized structures indicated that only the indole derivative 2e showed the same aromatic fragment orientation as 1a, which allows us to define a volume that is not accessible to ligands in the enzyme and consequently to a refined model of the choline acetyltransferase recognition site.

Interrelation between electrostatic and lipophilicity potentials on molecular surfaces.

Molecular electrostatics and lipophilicity are two important properties included in quantitative structure-activity relationships (QSARs) employed for rational drug design. The molecular electrostatic potential (MEP) provides information on the position, distribution, and extent of electrophilic and nucleophilic regions around a molecule. Similarly, the solvent affinity can be represented by a local phenomenological potential of semiempirical nature: the molecular lipophilicity potential (MLP). Although a simultaneous, three-dimensional display of MEP and MLP is possible, it may not provide a practical tool for comparing molecules. In this work, we deal with the simpler two-dimensional maps of the entire molecular surface projected onto an MEP-MLP plane. We analyze how these maps change with the following factors: (1) composition and molecular geometry, (2) the quality of the computation of MEP, and (3) the parameter set used for evaluating the lipophilicity potential. The approach is used to compare series of pyrazole derivatives. The methodology is useful in assessing molecular similarity, as well as in establishing the nature of differences between compounds.

Effect of branching in 4-alkylpyrazoles on liver alcohol dehydrogenase inhibition: a shape analysis study.

Shape analysis methodology is applied to the study of 4-alkylpyrazoles which are known inhibitors of liver alcohol dehydrogenase. Elongation of the alkyl chain increases the inhibitory power, whereas branching of the chain diminishes the activity. These two counterpoised effects are studied simultaneously in a selected set of 4-alkylpyrazoles. A systematic conformational analysis followed by topological characterization of the van der Waals surfaces of all the local minima restricts the conformational space to potential bioactive structures. The analysis of the interrelation between the molecular electrostatic potential and van der Waals surfaces provides certain shape codes characteristic of each 4-alkylpyrazole. In both topological analyses (van der Waals surfaces and molecular electrostatic potential-van der Waals surface interrelations) graphical representations and analytical methods were used. A good correlation between the shape codes and the inhibitory activity is found for the linear derivatives. For branched pyrazoles, a tendency in their inhibitory power is predicted. Isopentylpyrazole is suggested to have the same inhibitory profile as 4-butylpyrazole, the linear derivative with one less carbon atom.

Synthesis of 4-alkylpyrazoles as inhibitors of liver alcohol dehydrogenase.

Theoretical studies by shape analysis of the molecular electrostatic potential on the van der Waals surfaces of a set of 4-alkylpyrazoles predicted 4-isopentyl derivative as a good inhibitor of liver alcohol dehydrogenase. Thus, the new 4-isopentyl and the already known 4-octylpyrazole have been prepared by a novel route. The isopentyl derivative has been tested as inhibitor of horse liver alcohol dehydrogenase giving the result predicted by the theoretical studies.

Alteration of renal carnitine metabolism by anticonvulsant treatment.

We administered therapeutic doses of valproic acid (VPA), carbamazepine (CBZ), phenytoin (PHT), and phenobarbital (PHB) to mice for 7 days, and 8 hours after the final dose we measured the concentrations of carnitine in serum, liver, kidney, skeletal muscle, and heart, and in the 7 days' accumulated urine. The results for serum and urine show that VPA induced a significant increase in renal clearance of acylcarnitine without affecting that of free carnitine, whereas CBZ, PHT, and PHB significant increased clearance of free carnitine but not that of acylcarnitine. Thus, VPA appears to reduce tubular resorption of acylcarnitine, and CBZ, PHT, and PHB appear to reduce tubular resorption of free carnitine.

Short-term effects of administration of anticonvulsant drugs on free carnitine and acylcarnitine in mouse serum and tissues.

1. The short-term evolution of concentrations of free carnitine and acylcarnitine was studied in the serum, liver, kidney, heart and skeletal muscle of mice after administration of single therapeutic doses of the anticonvulsant drugs, valproic acid (VPA), carbamazepine (CBZ), phenytoin (PHT) and phenobarbitone (PHB). 2. The effects of the drugs were immediate but transitory, control levels of free carnitine and acylcarnitine having been recovered or almost recovered in serum and in all tissues 8 h post administration (p.a.). 3. VPA was the only drug that significantly reduced free carnitine concentration in serum, which recovered control levels by 4 h p.a. 4. All the drugs studied brought about marked deficits of serum acylcarnitine, which had disappeared 2 h p.a. in the case of VPA and not until 8 h p.a. for CBZ, PHT or PHB. 5. The minimum concentrations of free carnitine and acylcarnitine in serum were invariably associated with the maximum concentration of drug in serum. 6. Free carnitine concentration was not affected by VPA in any tissue, PHT and PHB brought about significant deficits in heart and kidney, and CBZ a significant deficit in muscle. 7. Acylcarnitine concentration was significantly reduced in heart, kidney and muscle by CBZ, PHT and PHB, but in liver the effects of all drugs were very small. 8. These results are compatible with the hypothesis that the primary cause of anticonvulsant-induced alteration of carnitine metabolism is interference with renal reabsorption of carnitine.

Free carnitine and acylcarnitine levels in sera of alcoholics.

We report the free, acyl-, and total carnitine contents of 49 clinically healthy volunteers and 167 chronic alcoholics with various clinically and/or anatomopathologically identified degrees of hepatic affection. There was a gradual upward trend in carnitine levels as the degree of hepatic affection increased. In cirrhotic patients, both free and acylcarnitine levels were significantly higher than normal, but there was no systematic hypercarnitinemia in other stages of alcoholism; on the contrary, noncirrhotic alcoholic patients accounted for 82.6% of all hypocarnitinemia cases. Hypercarnitinemia among cirrhotic alcoholics was due chiefly to increased free carnitine concentrations. Acylcarnitine levels in patients with hepatic steatosis were significantly higher than those in normal subjects (P less than 0.001), but there were no other statistically significant differences in either acyl- or free carnitine levels between normals on the one hand and, on the other, patients with hepatic steatosis, alcoholic hepatitis, slight hepatopathy, or chronic hepatopathy without portal hypertension.

A structure-reactivity study of the binding of acetylglutamate to carbamoyl phosphate synthetase I.

The requirements for binding at the N-acetyl-L-glutamate binding site of carbamoyl phosphate synthetase I were studied by the displacement of the activator from the central enzyme complex by analogs. Two carboxyls are essential and the acetamido group, if linked to the alpha-carbon, enhances binding 5000-fold. The subsite for the delta-carboxyl is mobile with respect to that for the alpha-carboxyl. Mixtures of complementary fragment of acetylglutamate do not bind, indicating a strong 'chelate' effect. Substituents revealed the existence of steric constraints around the delta-carboxyl, the alpha and gamma-carbons, and the whole of the acetamido group. However, phenyl substituents at the beta-carbon did not hamper binding, indicating that substituents at the beta-carbon face the solution. This is consistent with binding of acetylglutamate as the minimum-energy conformer. All analogs binding with high affinity are activators. Some analogs that bind poorly are competitive inhibitors. They appear to bind preferentially to a low-affinity conformation adopted by the site when the products dissociate and the substrates bind. The acetamido group plays no role in the binding of the inhibitors but it is crucial for the binding of the activators, and the high- and low-affinity conformations of the site differ markedly in structural selectivity.

Effects of acute valproate administration on carnitine metabolism in mouse serum and tissues.

Carnitine concentrations in serum, liver, kidney, muscle and heart were determined 30 min, 2 hr and 4 hr after administration of single 50 mg/kg doses of valproic acid (VPA) or octanoic acid (OTA) of fasting mice. Half an hour post-administration (p.a.) of VPA, free carnitine concentrations were smaller than in controls in serum, liver, kidney and heart. Four hr p.a., the effects of VPA had disappeared from all the carnitine sources, which now had concentrations that were not significantly different from those of controls. The effects of OTA are different from, and sometimes the opposite of, those of VPA, showing that the effects of VPA are specific to it. Hyperammonemia, on the other hand, was greatest 4 hr p.a. of VPA. These findings show that the effect of VPA on carnitine metabolism is immediate but transient, and accordingly suggest that the carnitine deficiency observed in patients under prolonged treatment with VPA-containing anticonvulsants must be due to a more complex mechanism than direct interaction between carnitine and VPA.

Carnitine deficiency associated with anticonvulsant therapy.

Valproic acid therapy is known to be associated with carnitine deficiency in adult as well as young epileptic patients. In a study of the possible existence of such side-effects with other anticonvulsants, 76.5% of adult patients treated with valproate were deficient in serum free carnitine, with acylcarnitine levels significantly higher than in controls (p less than 0.01), while the carnitine deficiency rate in a group of patients treated with anticonvulsants other than valproate was 21.5%. Since in clinical practice only about one fifth of patients are treated with valproate, this means that about 15% of epileptics are carnitine deficient because of valproate treatment and 17% because of other anticonvulsants. The mechanisms and clinical and biological consequences of the carnitine deficiency associated with antiepileptic drugs other than valproate are not known.