Clinical and genetic yield of familial screening after a sudden unexplained death at a young age

BACKGROUND

In a population under 45 years of age, the predominant causes of sudden cardiac death (SCD) are inherited cardiac diseases. Determining the underlying cause may help identify relatives at risk and prevent further events but is more difficult if an autopsy has not been performed.

AIMS

We aimed to assess the diagnostic value of clinical and genetic screening in relatives of young non-autopsied sudden unexplained death (SUD) victims.

MATERIAL AND METHODS

Eighty-seven relatives of 65 young non-autopsied SUD victims from 39 families were evaluated from 2016 to 2019. The relatives underwent extensive noninvasive cardiac workup. Genetic examinations were performed in 39 families.

RESULTS

The definite diagnoses were made in 17 of 39 (44%) families. Cardiomyopathies were identified in 10 families (5 hypertrophic, 4 dilated, and 1 arrhythmogenic), followed by long QT syndrome (5 families). In 3 families, probable diagnoses were made, whereas in 20 families no diagnosis was achieved. In total, definite and probable diagnoses were made in 18 and 5 patients, respectively. All affected relatives were offered medical management, one of them died of heart failure and one underwent transplantation during the median follow-up of 3 years. Disease-causing variants were found in 7 of 39 (18%) probands; all in families with a definite diagnosis. Variants of unknown significance were found in 2 probands.

CONCLUSION

Screening of relatives of SUD victims is warranted and may save lives, even if it is not guided by autopsy results. Genetic testing in families without the disease phenotype has little effectiveness.

A MYH7 variant in a five-generation-family with hypertrophic cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is a genetic condition with a prevalence of 1:500-1:3 000. Variants in genes encoding sarcomeric proteins are mainly responsible for the disease. MYH7 gene encoding a myosin heavy chain beta, together with MYPBC3 gene are the two most commonly affected genes. The clinical presentation of this disease varies widely between individuals. This study aims to report a variant of MYH7 responsible for HCM in a five-generation family with a history of cardiac problems. Methods: The diagnosis was established according to the European Society of Cardiology HCM criteria based on two-dimensional Doppler echocardiography or cardiovascular magnetic resonance. Genetic analysis was performed using next-generation-sequencing and Sanger method. Results: The medical history of the presented family began with a prenatal diagnosis of HCM in the first child of a family with previously healthy parents. Five generations of the family had a long history of sudden cardiac death and cardiac problems. A NM_000257.4:c.2342T>A (p.Leu781Gln) variant was detected in the MYH7 gene. It was heterozygous in the proband and in all affected individuals in a large family. The variant was present in 10 affected members of the family, and was absent in 7 members. The clinical course of the disease was severe in several members of the family: three family members died of sudden cardiac death, one patient required heart transplantation, three underwent septal myectomy, and three required implantable cardioverter defibrillator (ICD) implantation. Conclusion: Herein, we report a MYH7 variant responsible for HCM. Familial HCM is inherited primarily in autosomal dominant mode, which is in accordance with our study. However, the presented family showed a broad clinical spectrum of HCM. Out of 10 family members with positive genetic testing 8 had severe presentation of the disease and 2 had a mild phenotype. This suggests that the severity of the disease may depend on other factors, most likely genetic.

Cardiovascular involvement and prognosis in Loeys-Dietz syndrome

BACKGROUND

Loeys-Dietz syndrome (LDS) is an inherited connective tissue disorder associated with aortic root enlargement and risk of thoracic aortic dissection (AD). Genetic examination is essential for diagnosis.

AIMS

The study aimed at analysis of clinical data on cardiovascular involvement and management of LDS patients.

METHODS

The study included carriers of LDS-associated genetic variants, identified between 2012 and 2022. Assessment of cardiovascular involvement was based on echocardiography and computed tomography angiography with quantitative assessment of arterial tortuosity. Involvement of other systems was also evaluated. We noted major cardiovascular events, including aortic events, defined as AD, elective aortic surgery, or otherwise unexplained sudden death.

RESULTS

Thirty-four patients from 15 families were included, and five identified variants were novel. Probands' mean age was 41 years. Cardiovascular abnormalities, aortic involvement, aortic tortuosity, and tortuosity of cervical arteries were present in 79%, 71%, 68%, and 100% of carriers, respectively. First aortic events (9 A-type AD, 6 elective thoracic aortic surgeries, and one sudden death) occurred in 16 (47%) patients at a median age of 35 years. The youngest age at AD was 16 years, and 7 years for elective aneurysm repair. Second and third aortic events occurred in 9 and 4 patients, respectively. Eight patients (24%) experienced other major cardiovascular events. Aortic event-free survival was shorter in the presence of skin striae (P = 0.03), tended to be shorter in the presence of Marfanoid features (P = 0.06), and longer with TGFB2 variants (P = 0.06).

CONCLUSIONS

LDS is associated with high burden of cardiovascular complications at a young age.

The complete anatomy of the lingual nerve: A meta-analysis with implications for oral and maxillofacial surgery

Lingual nerve (LN) injury during surgical procedures in the third molar region warrants a detailed study of its common pathway and important variations. Therefore, the objective of this study was to analyze and compile the multiple anatomical variations of the LN for use in oral and maxillofacial surgery. It is anticipated that the results of the present meta-analysis may help to minimize the possible complications when performing procedures associated with this anatomical entity. Major online databases such as PubMed, Web of Science, Scopus, Embase were used to gather all relevant studies regarding the LN anatomy. The results were established based on a total of 1665 LNs. The pooled prevalence of the LN being located below the lingual/ alveolar crest was found to be 77.87% (95% CI: 0.00%-100.00%). The LN was located above the lingual/ alveolar crest in 8.21% (95% CI: 4.63%-12.89%) of examined nerves. The most common shape of the LN was established to be round with a prevalence of 40.96% (95% CI: 23.96%-59.06%), followed by oval at 37.98% (95% CI: 23.98%-53.02%) and flat at 25.16% (95% CI: 12.85%-39.77%). In conclusion, we believe that this is the most accurate and up-to-date study regarding the anatomy of the LN. The LN was found to be located below the lingual/alveolar crest in 77.87% of the cases. Furthermore, the LN was found to enter the tongue under the submandibular duct in 68.39% of the cases. Knowledge about the anatomy of the LN is crucial for numerous oral and maxillofacial procedures such as during the extraction of the third molar.

Association between common cardiovascular risk factors and clinical phenotype in patients with hypertrophic cardiomyopathy from the European Society of Cardiology (ESC) EurObservational Research Programme (EORP) Cardiomyopathy/Myocarditis registry

AIMS

The interaction between common cardiovascular risk factors (CVRF) and hypertrophic cardiomyopathy (HCM) is poorly studied. We sought to explore the relation between CVRF and the clinical characteristics of patients with HCM enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy registry.

METHODS AND RESULTS

1739 patients with HCM were studied. The relation between hypertension (HT), diabetes (DM), body mass index (BMI), and clinical traits was analysed. Analyses were stratified according to the presence or absence of a pathogenic variant in a sarcomere gene. The prevalence of HT, DM, and obesity (Ob) was 37, 10, and 21%, respectively. HT, DM, and Ob were associated with older age (P<0.001), less family history of HCM (HT and DM P<0.001), higher New York Heart Association (NYHA) class (P<0.001), atrial fibrillation (HT and DM P<0.001; Ob p = 0.03) and LV (left ventricular) diastolic dysfunction (HT and Ob P<0.001; DM P = 0.003). Stroke was more frequent in HT (P<0.001) and mutation-positive patients with DM (P = 0.02). HT and Ob were associated with higher provocable LV outflow tract gradients (HT P<0.001, Ob P = 0.036). LV hypertrophy was more severe in Ob (P = 0.018). HT and Ob were independently associated with NYHA class (OR 1.419, P = 0.017 and OR 1.584, P = 0.004, respectively). Other associations, including a higher proportion of females in HT and of systolic dysfunction in HT and Ob, were observed only in mutation-positive patients.

CONCLUSION

Common CVRF are associated with a more severe HCM phenotype, suggesting a proactive management of CVRF should be promoted. An interaction between genotype and CVRF was observed for some traits.

Good performance of the criteria of American College of Medical Genetics and Genomics/Association for Molecular Pathology in prediction of pathogenicity of genetic variants causing thoracic aortic aneurysms and dissections

BACKGROUND

The identification of pathogenic variant in patients with thoracic aortic aneurysms and dissections (TAAD) was previously found to be a significant indicator pointing to earlier need for surgical intervention. In order to evaluate available methods for classifying identified genetic variants we have compared the event-free survival in a cohort of TAAD patients classified as genotype-positive versus genotype-negative by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG-AMP) criteria or by ClinVar database.

METHODS

We analyzed previously unreported cohort of 132 patients tested in the routine clinical setting for genetic variants in a custom panel of 30 genes associated with TAAD or the TruSight Cardio commercial panel of 174 genes associated with cardiac disease. The identified variants were classified using VarSome platform. Kaplan-Meier survival curves were constructed to compare the event-free survival between probands defined as 'genotype-positive' and 'genotype-negative' using different classifications in order to compare their performance.

RESULTS

Out of 107 rare variants found, 12 were classified as pathogenic/likely pathogenic by ClinVar, 38 were predicted to be pathogenic/likely pathogenic by ACMG. Variant pathogenicity as assessed by ACMG criteria was a strong predictor of event free survival (event free survival at 50 years 83% vs. 50%, for genotype positive patients vs. reference, respectively, p  = 0.00096). The performance of ACMG criteria was similar to that of ClinVar (event free survival at 50 years 87% vs. 50%, for genotype positive patients vs. reference, respectively p  = 0.023) but independent from it as shown by analysing variants with no ClinVar record (event free survival at 50 years 80% vs. 50%, p  = 0.0039). Variants classified as VUS by ACMG criteria or ClinVar did not affect event-free survival. TAAD specific custom gene panel performed similar to the larger universal cardiac panel.

CONCLUSIONS

In our cohort of unrelated TAAD patients ACMG classification tool available at VarSome was useful in assessing pathogenicity of novel genetic variants. Gene panel containing the established genes associated with the highest risk of hereditary TAAD (ACTA1, COL3A1, FBN1, MYH11, SMAD3, TGFB2, TGFBR1, TGFBR2, MYLK) was sufficient to identify prevailing majority of variants most likely to be causative of the disease.

The emerging role of reassessment of genetic testing results in the diagnosis of the unexplained sudden cardiac arrest's causes

Background

The most common cause of Unexplained Sudden Cardiac Arrest (USCA) are hereditary primary arrhythmic syndromes and subclinical forms of cardiomyopathies. Both of them may be difficult to diagnose.

Objective

The aim of this study was to re-examine the role of genetic testing in patients after USCA during follow-up.

Methods

In the years 2014–2017 we studied 44 unrelated patients (pts) (23 men (53%), mean age 36 years) after USCA. All pts underwent cardiac evaluation including ECG, Holter, echo, coronary angiography, stress exercise test and, if necessary cardiac MRI and provocative drug testing. Standard diagnostic criteria were used according to currently available ESC guidelines. We performed next generation sequencing with panel covered coding regions of &gt;4800 genes (26pts), 194 genes (5pts) and whole exome sequencing &gt;2ehab724.3204 genes (5pts). Variants of frequency no greater than 0,001 in existing variants' databases and classified as damaging by at least 3 of applied software algorithms were assessed for pathogenicity according to ACMG standards. The enrolled patients were followed up. During the follow up, the classification of rare variants according to ACMG standards was repeated.

Results

Based on applicable standards and the clinical data collected, clinical diagnosis was made in 17 (39%) probands (Long QT Syndrome 21%, Brugada Syndrome 7%, Short QT Syndrome 7%, Early Repolarization Syndrome and Catecholaminergic Polymorphic Ventricular Tachycardia 2%, both). Genetic tests were performed in 36 pts. We identified 27 rare variants in 22 pts, in genes associated with inherited arrhythmia or cardiomyopathies, of these 23 rare variants were identified in years 2014–2017. The first classification was in 2017, then only 2 variants (in FLNC) were considered pathogenic and the remaining 21 were classified as Variants of Unknown Significance (VUS). During the years 2019–2021, 23 earlier identified rare variants were reclassified according to The American College of Medical Genetics and Genomics (ACMG) standards, of these 5 VUS became pathogenic/likely pathogenic variants. In addition, we performed genetic tests in next 5 pts – we identified 4 rare variants – 3 pathogenic and 1 VUS.

Detection of certain hereditary background of SCA increased from 6,5% in years 2014–2017, to 25% in years 2019–2021.

The median follow-up period was 2366 days (interquartile range 1785–2903 days). 17/44 (39%) pts had adequate discharge of ICD. Two pts were observed with reduction of left ventricular contractility and the development of the initial stages of dilated cardiomyopathy.

Conclusion

This study shows clinical utility of extensive clinical assessment and follow-up of patient after USCA. Routine genetic testing by next generation sequencing in the patients can help in diagnosis and re-evaluation of rare variants should be made during the follow-up.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): grant of National Institute of Cardiology, Warsaw, Poland

A novel risk model for predicting potentially life-threatening arrhythmias in non-ischemic dilated cardiomyopathy (DCM-SVA risk)

BACKGROUND

Non-ischemic dilated cardiomyopathy (DCM) can be complicated by sustained ventricular arrhythmias (SVA) and sudden cardiac death (SCD). By now, left-ventricular ejection fraction (LV-EF) is the main guideline criterion for primary prophylactic ICD implantation, potentially leading either to overtreatment or failed detection of patients at risk without severely impaired LV-EF. The aim of the European multi-center study DETECTIN-HF was to establish a clinical risk calculator for individualized risk stratification of DCM patients.

METHODS

1393 patients (68% male, mean age 50.7 ± 14.3y) from four European countries were included. The outcome was occurrence of first potentially life-threatening ventricular arrhythmia. The model was developed using Cox proportional hazards, and internally validated using cross validation. The model included seven independent and easily accessible clinical parameters sex, history of non-sustained ventricular tachycardia, history of syncope, family history of cardiomyopathy, QRS duration, LV-EF, and history of atrial fibrillation. The model was also expanded to account for presence of LGE as the eight8h parameter for cases with available cMRI and scar information.

RESULTS

During a mean follow-up period of 57.0 months, 193 (13.8%) patients experienced an arrhythmic event. The calibration slope of the developed model was 00.97 (95% CI 0.90-1.03) and the C-index was 0.72 (95% CI 0.71-0.73). Compared to current guidelines, the model was able to protect the same number of patients (5-year risk ≥8.5%) with 15% fewer ICD implantations.

CONCLUSIONS

This DCM-SVA risk model could improve decision making in primary prevention of SCD in non-ischemic DCM using easily accessible clinical information and will likely reduce overtreatment.

P2826Clinical and genetic yield of familiar screening after sudden death of young patients

Background

In Europe, approximately 9000 patients under the age of 45 die suddenly every year. In this group the predominant reasons of sudden death (SD) are channelopathies, cardiomyopathies, myocarditis and substance abuse. The main challenge is the identification of the cause of an unexpected death, especially when the autopsy was not done routinely.

Objective

The aim of the study was to investigate the value of clinical and genetic screening in relatives of subjects who died suddenly under the age of 45.

Methods

In the years 2017–2018 we evaluated 53 relatives (41 1st degree) of 25 young SD subjects. Clinical screening included a review of medical history, clinical examination, ECG, transthoracic echocardiogram, 24- hour EKG Holter monitoring, stress test and, cardiac MRI, provocative drug tests, if necessary. Standard diagnostic criteria were used according to currently available ESC guidelines. The most affected 1st degree relative of the SD victim was named as proband.

DNA samples from 25 probands were examined by next generation sequencing (NGS) using a custom panel which included 174 genes associated with 17 cardiac diseases-TruSight Cardio (TSC) panel. Variants identified with NGS were followed-up in probands and other relatives with Sanger sequencing.

Baseline analysis of NGS results was based on searching for genetic variants with very low frequency (<0.001) with high bioinformatic prediction scores with special regard to phenotypically consistent genes. The frequencies of variants were compared with the GnomAD database, Phase 3 of 1000 Genomes, NHLBI GO Exome Sequencing Project (ESP) 6500. For the bioinformatic prediction scores we used data summarized in VarSome database. The clinical significance of the variants was based on ClinVar database.

Results

Based on comprehensive clinical evaluation of relatives the diagnosis was made in 16/25 (64%) families, namely long QT syndrome (n=7/16; 43,75%), hypertrophic cardiomyopathy (n=5/16; 31,25%), Brugada syndrome (1/16; 6,25%), arrhythmogenic right ventricular cardiomyopathy (n=1/16; 6,25%), thoracic aortic aneurysm (n=1/16; 6,25%) and complete heart block (n=1/16; 6,25%). In 9/25 families (36%) exams showed minor abnormalities, but definite diagnosis could not be made.

We found pathogenic variants in 11/25 (44%) probands. We identified 9 variants in a subgroup of probands with diagnosis (frameshift in MYBPC3 and PKP2, missense variants in KCNQ1, SCN3B, SCN5A,MYH7,TPM1, SCN2B, KCNH2 genes) and 2 variants in a subgroup of probands without diagnosis (frameshift in TTN gene and a missense in KCNH2 gene).

Conclusion

This study shows that clinical and genetic familial screening after sudden death of young patients may be effective, helps in identifying individuals at risk and allows to implement an adequate treatment to prevent subsequent sudden death.

Acknowledgement/Funding

Institute of Cardiology in Anin 2.9/II/17

5,20-BIS(4-Sulphophenyl)-10,15-Bis(2-Methoxy-4-Sulphophenyl)-21-Thiaporphyrin as a new Potent Sensitizer in Photodynamic Therapy

The main purpose of the study was to investigate the effectiveness of a new photosensitizer for photodynamic therapy. 5,20-bis(4-sulphophenyl)-10,15-bis(2-methoxy-4-sulphophenyl)-21-thiaporphyrin (21-thiaporphyrin) was compared to chlorin e6 and tetra(m-hydroxyphenyl)porphyrin (m-THPP) for its ability to sensitize tumors and skin to light. Chlorin e6 and m-THPP induced a strong tumor and skin photosensitization. In contrast, the same doses of 21-thiaporphyrin produced no skin sensitization and gave approximately 10 mm tumor necrosis after light exposure, in comparison to the 5-6 mm necrosis induced by chlorin e6 or m-THPP under identical conditions. 21-Thiaporphyrin, tested as a potential photosensitizer, induced no skin sensitization even at doses as high as 7.5 mg/kg body weight. 21-Thiaporphyrin presents a high potency in tumor sensitizing, i.e. a feature required for an efficient photosensitizer in photodynamic therapy applications.

Next-generation sequencing for diagnosis of thoracic aortic aneurysms and dissections: diagnostic yield, novel mutations and genotype phenotype correlations

Background

Thoracic aortic aneurysms and dissections (TAAD) are silent but possibly lethal condition with up to 40 % of cases being hereditary. Genetic background is heterogeneous. Recently next-generation sequencing enabled efficient and cost-effective examination of gene panels. Aim of the study was to define the diagnostic yield of NGS in the 51 TAAD patients and to look for genotype–phenotype correlations within families of the patients with TAAD.

Methods

51 unrelated TAAD patients were examined by either whole exome sequencing or TruSight One sequencing panel. We analyzed rare variants in 10 established thoracic aortic aneurysms-associated genes. Whenever possible, we looked for co-segregation in the families. Kaplan–Meier survival curve was constructed to compare the event-free survival depending on genotype. Aortic events were defined as acute aortic dissection or first planned aortic surgery.

Results and discussion

In 21 TAAD patients we found 22 rare variants, 6 (27.3 %) of these were previously reported, and 16 (73.7 %) were novel. Based on segregation data, functional analysis and software estimations we assumed that three of novel variants were causative, nine likely causative. Remaining four were classified as of unknown significance (2) and likely benign (2). In all, 9 (17.6 %) of 51 probands had a positive result when considering variants classified as causative only and 18 (35.3 %) if likely causative were also included. Genotype-positive probands (n = 18) showed shorter mean event free survival (41 years, CI 35–46) than reference group, i.e. those (n = 29) without any plausible variant identified (51 years, CI 45–57, p = 0.0083). This effect was also found when the ‘genotype-positive’ group was restricted to probands with ‘likely causative’ variants (p = 0.0092) which further supports pathogenicity of these variants. The mean event free survival was particularly low (37 years, CI 27–47) among the probands with defects in the TGF beta signaling (p = 0.0033 vs. the reference group).

Conclusions

This study broadens the spectrum of genetic background of thoracic aneurysms and dissections and supports its potential role as a prognostic factor in the patients with the disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0870-4) contains supplementary material, which is available to authorized users.

Blood vessels of the shin - posterior tibial artery - anatomy - own studies and review of the literature

Anatomy of the vascular system of the leg was studied using classical anatomical dissection methods. Based also on literature we have reviewed the current knowledge on the vascularization of the lower leg and its embryological background with special respect toward the posterior tibial artery and its branches.

Blood vessels of the shin - anterior tibial artery - anatomy and embryology - own studies and review of the literature

Injuries of the lower leg are rather frequent in every day orthopedic routine. Process of healing takes quite a long time and is commonly dependent on the proper vasculature. e study was carried out on 50 human lower legs obtained during autopsies. The anatomy of the vascular system of the leg was studied using classical anatomical dissection methods. Based also on literature we have reviewed the current knowledge on the vascularization of the lower leg and its embryological background.

A study in Polish patients with cardiomyopathy emphasizes pathogenicity of phospholamban (PLN) mutations at amino acid position 9 and low penetrance of heterozygous null PLN mutations

Background

In humans mutations in the PLN gene, encoding phospholamban - a regulator of sarcoplasmic reticulum calcium ATPase (SERCA), cause cardiomyopathy with prevalence depending on the population. Our purpose was to identify PLN mutations in Polish cardiomyopathy patients.

Methods

We studied 161 unrelated subjects referred for genetic testing for cardiomyopathies: 135 with dilated cardiomyopathy, 22 with hypertrophic cardiomyopathy and 4 with other cardiomyopathies. In 23 subjects multiple genes were sequenced by next generation sequencing and in all subjects PLN exons were analyzed by Sanger sequencing. Control group included 200 healthy subjects matched with patients for ethnicity, sex and age. Large deletions/insertions were screened by real time polymerase chain reaction.

Results

We detected three different heterozygous mutations in the PLN gene: a novel null c.9_10insA:(p.Val4Serfs*15) variant and two missense variants: c.25C > T:(p.Arg9Cys) and c.26G > T:(p.Arg9Leu). The (p.Val4Serfs*15) variant occurred in the patient with Wolff-Parkinson-White syndrome in whom the diagnosis of cardiomyopathy was not confirmed and his mother who had concentric left ventricular remodeling but normal left ventricular mass and function. We did not detect large deletions/insertions in PLN in cohort studied.

Conclusions

In Poland, similar to most populations, PLN mutations rarely cause cardiomyopathy. The 9^thPLN residue is apparently a mutation hot spot whereas a single dose of c.9_10insA, and likely other null PLN mutations, cause the disease only with low penetrance or are not pathogenic.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0167-0) contains supplementary material, which is available to authorized users.

Inferior tibiofibular joint (tibiofibular syndesmosis) - own studies and review of the literature

The study was carried out on 50 human lower legs obtained during autopsies. The anatomy of the joint was studied using classical anatomical description methods. Based also on literature we have reviewed the current knowledge on the inferior tibiofibular joint.

Vascular architecture of the human uterine cervix, as assessed in light- and scanning electron microscopy

BACKGROUND

The aim of this study was to visualise and describe the vasculature of the human uterine cervix.

MATERIAL AND METHODS

The material for this study was obtained from women (age between 20 to 45 years) during autopsy. The material was collected not later than 24 h post-mortem. This study was performed using uteri from cadavers of menstruating nulliparas (33 uteri) and menstruating multiparas (27 uteri). Collected uteri were perfused via the afferent vessels with Mercox resin (for corrosion-casting and SEM assessment) or acrylic paint solution (light microscopy assessment). The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/121/8/2007).

RESULTS

In all cases bilateral cervical branches (1-4), originating from the uterine artery, were found. Both in the vaginal and supravaginal parts of the cervix, four distinct vascular zones were found. In the pericanalar zone ran small veins, responsible for draining the mucosal capillaries. Both in the muscular layer, as well as in the pericanalar zone, arterioles, and venules passed close to each other, often adjoining.

CONCLUSIONS

This study does not confirm the existence of a single cervicovaginal artery, but shows that the vascular supply of the cervix comes from several vessels. It also introduces the idea of two systems, responsible for draining blood from the mucosal capillaries. Neither assessment in light microscopy nor in SEM revealed any differences between multiparas and nulliparas, regarding the vascular architecture of the cervix.

Tumor histopathology following new sensitizers: dithiaporphyrin- and sulfoxaporphyrin-mediated photodynamic therapy

BACKGROUND

Our main aim was to evaluate tumor histopathology following new sensitizer-mediated photodynamic therapy (PDT).

MATERIALS AND METHODS

In order to complete our studies we decided to use photosensitizers, i.e. dithiaporphyrin (DTP) and sulfoxaporphyrin (OXA) in combination with halogen lamp irradiation of presensitized tumors. The doses of sensitizers were: 2.5, 5.0, 7.5 and 10.0 mg/kg of body weight and total light doses were: 50, 100 and 150 J/sq.cm at the selected wavelength. Following such a treatment we have evaluated tumor necrosis of BFS1 fibrosarcoma growing on BALB/c mice. Together with tumor necrosis evaluation we have examined skin response to photodynamic treatment.

RESULTS

We have found that both new sensitizers caused significant tumor damage at no skin alterations. The induction of tumor necrosis seemed to be dose dependent, i.e. higher photodynamic doses (sensitizer dose x light dose) resulted in more severe damage to the tumors than the lower doses.

CONCLUSION

Our study showed that BFS1 fibrosarcoma is highly sensitive to PDT after application of new sensitizers. Both compounds can be considered as potent tumor photosensitizers in future clinical trials.

New potent sensitizers for photodynamic therapy: 21-oxaporphyrin, 21-thiaporphyrin and 21,23-dithiaporphyrin induce extensive tumor necrosis

New sensitizers for photodynamic therapy (PDT) are reported. These compounds, namely 21-thiaporphyrin, 21,23-dithiaporphyrin and 21-oxaporphyrin, reveal some of the properties required for such therapy. Their physicochemical, chemical and pharmacological features meant that we could use them in the treatment of transplantable BFS1 fibrosarcoma in Balb/c mice. New sensitizers and the well-known chlorin e6 (Ce6) were used in doses of 2.5, 5.0, 7.5 and 10.0 mg/kg body weight, given intraperitoneally and followed by light irradiation, the total light doses being 50, 100 and 150 J/cm(2) within 24 h after injection. The effectiveness of new sensitizers in PDT was evaluated with in terms of tumor necrosis intensity, the survival time of treated animals, the rate of tumor response (complete/partial/no response), and skin photosensitivity. These results were compared to results obtained in analogous conditions after Ce6-PDT. Distribution studies revealed that the highest concentration of new compounds occurred within 24 h after injection. The results of these experiments confirmed that 21-thiaporphyrin, 21,23-dithiaporphyrin and 21-oxaporphyrin can be considered as potent tumor photosensitizers that do not exert any unwanted effects, primarily skin photosensitization. We suggest that these porphyrins are possible sensitizers to be applied in clinical PDT.

The new sensitizing agents for photodynamic therapy: 21-selenaporphyrin and 21-thiaporphyrin

BACKGROUND

Photodynamic therapy may be a promising treatment for patients with tumors. The mechanism of its action is poorly understood and different from the cytotoxic effects induced by antitumor drugs.

MATERIALS AND METHODS

New sensitizers, termed as 21-selenaporphyrin (SEP) and 21-thiaporphyrin (STSP) were studied for their photocytotoxicity in vitro against selected human cancer cell lines. This study was followed by in vivo screening of the effect of SEP using an animal tumor model. The activity of the new agents was compared with that of a known photosensitizer, namely chlorin e6. In our selection of the cell lines applied for in vitro study, the possible accessibility and effectiveness of photodynamic therapy (PDT) for treatment of colon and urinary bladder cancers, was considered.

RESULTS

New compounds appeared to be not toxic for tested cells in culture, without exposure to light. The STSP exerted in vitro effects comparable with chlorin e6 photocytotoxicity, while SEP appeared to be ineffective. However, in vivo experiments performed in a BFS1 fibrosarcoma tumor model in mice showed that the SEP was at least as much effective as chlorin e6 in the induction of tumor necrosis. In contrast to chlorin e6, SEP-PDT induced no skin sensitization.

CONCLUSIONS

Both new sensitizers can be applied in PDT at no risk of skin damage. The mechanism of the action of these two compounds is probably different, i.e. the 21-thiaporphyrin possibly acts directly on tumor cells and the 21-selenaporphyrin via endothelial cells of newly formed tumor vasculature.