Are There Any Differences in the Healing Capacity between the Medial Collateral Ligament's (MCL) Proximal and Distal Parts in the Human Knee? Quantitative and Immunohistochemical Analysis of CD34, α-Smooth Muscle Actin (α-SMA), and Vascular Endothelial Growth Factor (VEGF) Expression Regarding the Epiligament (EL) Theory.

The human knee is a complex joint that comprises several ligaments, including the medial collateral ligament (MCL). The MCL provides stability to the knee and helps prevent its excessive inward movement. The MCL also has a thin layer of connective tissue known as the epiligament (EL), which adheres to the ligament. This unique feature has drawn attention in the field of ligament healing research, as it may have implications for the recovery process of MCL injuries. According to the EL theory, ligament regeneration relies heavily on the provision of cells, blood vessels, and molecules. The present study sought to compare the expression of vascular endothelial growth factor (VEGF), CD34, and α-smooth muscle actin (α-SMA) in healthy knees' proximal and distal MCL segments to better understand how these proteins affect ligament healing. By improving the EL theory, the current results could lead to more effective treatments for ligament injury. To conduct the present analysis, monoclonal antibodies were used against CD34, α-SMA, and VEGF to examine samples from 12 fresh knee joints' midsubstance MCLs. We identified a higher cell density in the EL than in the ligament connective tissue, with higher cell counts in the distal than in the proximal EL part. CD34 immunostaining was weak or absent in blood vessels and the EL, while α-SMA immunostaining was strongest in smooth muscle cells and the EL superficial layer. VEGF expression was mainly in the blood vessels' tunica media. The distal part showed more SMA-positive microscopy fields and higher cell density than the proximal part (4735 vs. 2680 cells/mm2). Our study identified CD34, α-SMA, and VEGF expression in the MCL EL, highlighting their critical role in ligament healing. Differences in α-SMA expression and cell numbers between the ligament's proximal and distal parts may explain different healing capacities, supporting the validity of the EL theory in ligament recovery.

Do the Differences in the Epiligament of the Proximal and Distal Parts of the Anterior Cruciate Ligament Explain Their Different Healing Capacities? Quantitative and Immunohistochemical Analysis of CD34 and α-SMA Expression in Relation to the Epiligament Theory.

The aim of this study was to assess the epiligament theory by determining the normal epiligament morphology of the proximal and distal parts of the anterior cruciate ligament in humans and analyzing the differences between them and the midportion of the ligament in terms of cell numbers and expression of CD34 and α-SMA. Samples were obtained from the anterior cruciate ligaments of 12 fresh knee joints. Monoclonal antibodies against CD34 and α-SMA were used for immunohistochemistry. Photomicrographs were analyzed using ImageJ software, version 1.53f. The cell density was higher in the epiligament than in the ligament connective tissue. Cell counts were higher in the proximal and distal thirds than in the midsubstance of the epiligament. CD34 was expressed similarly in the proximal and distal thirds, although it seemed slightly more pronounced in the distal third. α-SMA expression was more robust in the proximal than the distal part. The results revealed that CD34 and α-SMA are expressed in the human epiligament. The differences between the numbers of cells in the proximal and distal parts of the epiligament and the expression of CD34 and α-SMA enhance epiligament theory. Future investigations into improving the quality of ligament healing should not overlook the epiligament theory.

Acute Myocardial Infarction in Young Individuals: Demographic and Risk Factor Profile, Clinical Features, Angiographic Findings and In-Hospital Outcome.

BACKGROUND: Cardiovascular diseases (CVDs) are the leading cause of global mortality and disability. Acute myocardial infarction (AMI) in young individuals is a rare condition but can cause devastating socioeconomic and psychological consequences for both the patient and their family and an economic burden for the government. There is a paucity of data concerning the specific profile of these young patients in Bulgaria, a country with a high burden of cardiovascular morbidity and mortality. Therefore, the aim of the present study was to assess the baseline characteristics, demographic and risk factor profile, clinical features, angiographic findings and in-hospital outcomes of young patients with AMI. Additionally, these data were compared to those of the older age group. METHODS: Retrospective data on 172 patients treated for AMI in "Prof. Alexandar Tschirkov", Bulgaria, from January 2018 to December 2021 were collected for the purpose of this study. Baseline characteristics, risk factor profile and clinical and angiographic features were compared in young (≤45 years) and older patients (>45 years). RESULTS: Males were significantly predominant in the two age groups (p < 0.01), with an obviously increasing proportion of females in the older age group. Young patients were more likely to be smokers (55.7% vs. 28.8%; p=0.001); in contrast, hypertension (70.5% vs. 91.9%; p <0.001) and obesity (16.4% vs. 31.5%; p=0.031) were more prevalent in older patients. Anterior localization of myocardial infarction (MI) was most common in the two age groups (47.5% vs. 41.4%), respectively. Regarding the time delay from symptom onset to first medical contact, we found that young patients tended to present earlier than their older counterparts. Young patients had a higher incidence of single vessel disease (SVD) (49.2%) and nonobstructive coronary disease (NOCD) (11.5%) than older patients. Young patients with AMI had a lower in-hospital morbidity rate than older patients, but the in-hospital mortality, although lower, was not significantly different. A high prevalence of modifiable cardiovascular risk factors (RFs), such as smoking, dyslipidemia and arterial hypertension (AH), among the young group, less evolved CAD and similar high procedural success between age groups were established. Approximately 30% of young patients tend to present late in the hospital. The in-hospital mortality in the young population was lower than that in the older population but was still relatively higher than that previously reported. CONCLUSION: The reported high prevalence of modifiable RFs and late presentation of young patients with AMI highlight the need for early recognition of these RFs, better prevention, deployment of educational programs, easy access to health care and high awareness of clinicians to reduce disability and mortality from CVD.

Variant origin of the right coronary artery from the left main coronary artery together with aortic valve stenosis: report of a rare case / Origen variante de la arteria coronaria derecha a partir de la arteria coronaria izquierda junto con estenosis de la valva aórtica: reporte de un caso raro

SUMMARY: Variations in the origin of the right coronary artery have an incidence between 0.09 % and 0.92 %. Herein, we report a rare case of a coronary artery anomaly in which the right coronary artery originates from the left main coronary artery. This variant was found during routine coronarography, combined with an artificial aortic valve. Despite their rare occurrence, some variations in the origins of the coronary arteries can be life threatening and are associated with a higher risk of sudden cardiac death. They can also pose serious technical challenges and predispose to complications during coronary angiographic procedures. Thus, knowledge of such anomalies is paramount for managing the patients correctly.

Las variaciones en el origen de la arteria coronaria derecha tienen una incidencia entre el 0,09 % y el 0,92 %. En este documento, informamos un caso raro de una anomalía de la arteria coronaria en la que la arteria coronaria derecha se originaba en la arteria coronaria izquierda. Esta variante se encontró durante una coronariografía de rutina, combinada con una válvula aórtica artificial. A pesar de su rara aparición, algunas variaciones en los orígenes de las arterias coronarias pueden poner en peligro la vida y se asocian con un mayor riesgo de muerte súbita cardíaca. También pueden plantear serios desafíos técnicos y predisponer a complicaciones durante los procedimientos angiográficos coronarios. Por tanto, el conocimiento de dichas anomalías es fundamental para el manejo correcto de los pacientes.

Patella cubiti - a continuing etiological mystery / Patella cubiti: un misterio etiológico continuo

SUMMARY: A sesamoid bone in the elbow joint is a rare anatomical variation described as a Patella cubiti. Although this variation has been known for centuries its exact etiology is still unclear. Congenital, developmental, and traumatic hypotheses have been proposed. It seldom causes clinical manifestations than elbow stiffness or hypomobility. Herein, we present a case of a 31-year-old patient admitted to our department with complaints of swelling and erythema in the right elbow. An X-ray image revealed a triangular accessory bone with rounded edges, which was diagnosed as a Patella cubiti in combination with olecranon bursitis. Knowledge of this rare elbow abnormality is paramount for orthopedic surgeons and roentgenologists in their daily medical practice.

Un hueso sesamoideo en la articulación del codo es una rara variación anatómica descrita como Patella cubiti. Aunque esta variación se conoce desde hace siglos, su etiología exacta aún no está clara. Se han propuesto hipótesis congénitas, de desarrollo y traumáticas. Rara vez causa manifestaciones clínicas que no sean rigidez o hipomovilidad del codo. Presentamos el caso de un paciente de 31 años que ingresó en nuestro servicio por presentar tumefacción y eritema en el codo derecho. Una imagen de rayos X reveló un hueso accesorio triangular con márgenes redondeados, que se diagnosticó como una Patella cubiti en combinación con bursitis del olécranon. El conocimiento de esta rara anomalía del codo es fundamental para los cirujanos ortopédicos y los médicos radiólogos en su práctica médica diaria.

A comparative study of the epiligament of the medial collateral and anterior cruciate ligaments in the human knee: Immunohistochemical analysis of CD 34, α-smooth muscle actin and vascular endothelial growth factor in relation to epiligament theory.

BACKGROUND: This study evaluated and compared the expression of VEGF, CD34, and α-SMA in the anterior cruciate ligaments and medial collateral ligaments in healthy human knees in order to enrich the epiligament theory regarding ligament healing after injury. METHODS: Samples from the mid-substance of the anterior cruciate ligament and the medial collateral ligament of 12 fresh knee joints were used. Monoclonal antibodies against CD34, α-SMA, and VEGF were used for immunohistochemical analysis. Photomicrographs were analyzed using the ImageJ software. RESULTS: The epiligament of the anterior cruciate ligament showed slightly higher expression of CD34, α-SMA, and VEGF than the epiligament of the medial collateral ligament. Overall, among the tested markers, α-SMA expression was most pronounced in anterior cruciate ligament epiligament images and CD34 dominated in medial collateral ligament epiligament images. The intensity of DAB staining for CD34, α-SMA, and VEGF was higher in vascular areas of the epiligament than in epiligament connective tissue. CONCLUSIONS: The results illustrate that CD34, α-SMA, and VEGF are expressed in the human epiligament. The differences between the epiligament of the investigated ligaments and the fact that CD34, α-SMA, and VEGF, which are known to have a definite role in ligament healing, are predominantly expressed in the main vascular part of the ligament-epiligament complex enlarge the existing epiligament theory. Future investigations regarding better ligament healing should not overlook the epiligament tissue.

A new variety of chondrocoracoideus muscle, or an additional head of pectoralis major muscle.

The pectoralis major and pectoralis minor muscles are located in the anterior chest wall. This region is characterized by high morphological variability. During dissection an additional muscle was found, originating from the lateral border of the pectoralis major muscle. After fusion it passed into the tendinous part coursing under the insertion of the pectoralis major muscle, then formed a common junction with the short head of the biceps brachii muscle, the distal attachment of which is on the coracoid process. Such an accessory structure could lead to neurovascular compression and cause thoracic outlet syndrome, of which pain is usually the first symptom. This muscle has not been described in the literature so far and for that reason we can name the present case as an unique structure.

A Case of 5-Fluorouracil-Induced Coronary Artery Vasospasm in a Patient With Salivary Gland Cancer.

5-Fluorouracil (5-FU), a pyrimidine analogue, is widely used in different chemotherapy regimens with established indications for the treatment of gastrointestinal, breast, head, and neck tumors. Various prospective studies including randomized controlled trials and retrospective reviews have shown a wide range of reported incidence of cardiotoxicity related to 5-FU use. This incidence is dependent on drug regimen, doses, concomitant therapy, patients' clinical characteristics, and risk factors. Herein, we present a clinical case of coronary vasospasm mimicking ST-elevation myocardial infarction during a 5-FU infusion for salivary gland cancer. Cardiologists and oncologists must keep in mind the potential life-threatening side effects of 5-FU on the heart and they must be familiar with the risk factors for their occurrence and their management strategies.

A Rare Case of Left Main Coronary Artery Aneurysm.

Coronary artery aneurysms are uncommon and are usually described as dilatations larger than 1.5 times the diameter of the adjacent coronary arteries. The aneurysms vary between 0.15% and 4.9% and usually affect the right coronary artery, followed by the circumflex and anterior descending artery. Left main coronary artery (LMCA) aneurysm is an extremely rare clinical entity. Herein, we present a case in a 69-year-old man with a prior history of chest pain and palpitations. Significant ischemic ST changes were registered on Holter electrocardiography during paroxysmal atrial fibrillation.

Hypertension-induced changes in the rat myocardium during the development of cardiac hypertrophy - a comparison between the left and the right ventricle.

The hypertrophy of the cardiac muscle is one of the most significant maladaptive mechanisms activated in response to increased workload. It is associated with histological and ultrastructural alterations, changes in the quantitative parameters and the expression of different enzymes. While the structural and functional consequences of systemic hypertension on the left ventricle have been well evaluated, the right ventricle has received less attention. The aim of the present study was to analyse and compare the changes in the left and right ventricle during the development of cardiac hypertrophy initiated by systemic hypertension in different age groups of spontaneously hypertensive rats. Therefore, we studied the histology and ultrastructure of the cells of the myocardium, evaluated the immunohistochemical expression of the enzyme neuronal nitric oxide synthase and conducted a quantitative analysis of several morphometric parameters. We used three groups of spontaneously hypertensive rats. For the quantitative analysis we also used three age groups of age- and weight-matched control animals (normotensive Wistar rats). In both ventricles, we described cardiomyocytic hypertrophy, focal myocytolysis and increased collagen deposition in the interstitial space. Our observations on the ultrastructural level were associated with changes in the cardiomyocytic nuclei, the arrangement, maturity and organisation of the myofibrils, the localisation and ultrastructure of the mitochondria, the development and maturity of the intercalated discs, as well as changes in the components of the interstitium. The immunohistochemical expression of neuronal nitric oxide synthase in the left ventricle was stronger than that in the right ventricle across all age groups. The comparative quantitative analysis revealed that changes in the studied morphometric parameters in the two ventricles occurred disproportionately. In conclusion, the present study characterised the development of cardiac hypertrophy in response to systemic hypertension in both ventricles and demonstrated the involvement of the right ventricle.

Osteoid Osteoma of the Middle Phalanx of the Third Finger in a Child Mimicking a Malignancy.

Osteoid osteoma is a rare occurrence in the hand, especially in children. We report here a rare case of a 12-year-old boy complaining of growing painful swelling of the middle phalanx of the third finger that had started 3 months earlier and had not responded to anti-inflammatory medication. Based on the clinical findings and plain radiographs, osteomyelitis or Ewing's sarcoma was suspected. However, MRI revealed the typical characteristics of osteoid osteoma. The lesion was excised, and the histological examination confirmed the diagnosis. We make a brief review of the literature concerning this uncommon localization and discuss the differential diagnosis and treatment modalities.

A Comparative Quantitative Analysis of the Postnatal Changes in the Myocardium of the Left and Right Ventricles in Rats.

BACKGROUND: The growth of the heart during the foetal and early postnatal development takes places mainly due to hyperplasia. The late postnatal development is characterised by cardiomyocytic hypertrophy in response to normal physiological mechanisms and increased load. To study the cell size most authors measure the diameter either directly or indirectly. AIM: The aim of the present study was to make a comparative quantitative analysis of the postnatal changes observed in the left and right ventricles in rat by evaluating the changes in three morphometric parameters - thickness of the free wall, transverse section of the cardiomyocytes and cardiomyocytic density in the left ventricle and right ventricle. MATERIALS AND METHODS: In the present study, we used histological material from the hearts of 15 male Wistar rats, distributed in five groups aged 2 weeks, 1 month, 3 months, 6 months and 12 months, respectively. RESULTS: In both ventricles, the wall thickness and the transverse section of the cardiomyocytes increased with age, while the cardiomyocytic density decreased. Changes were identical in both ventricles; however, they were more dynamic and pronounced in the left ventricle. CONCLUSIONS: The studied morphometric parameters reveal that age-related hypertrophy and the gradual loss of cardiac muscle cells take place in both ventricles but have a more dynamic pattern of progression in the left ventricle as compared with the right ventricle.

A Rare Case of Multiple Anomalies of the Coronary Arteries.

Coronary artery anomalies represent a rare phenomenon, which is observed in approximately 1% of the population. Although not a frequent anomaly, they may lead to complications during various procedures and can sometimes present with angina pectoris or myocardial infarction. Herein, we present a rare case of a patient with origin of the left main coronary artery from the right sinus of Valsalva combined with a superdominant right coronary artery due to a hypoplastic left circumflex artery. A 67-year-old male patient presented with symptoms of chest pain on exertion, which lasted for approximately 10 minutes and resolved after rest. Physical examination, auscultation, electrocardiogram, and transthoracic echocardiography revealed normal findings. Cardiac enzymes were within the reference ranges, while the levels of triglycerides and low density lipoprotein (LDL)-cholesterol were elevated. The patient was further evaluated through coronary angiography. It revealed the origin of the left coronary artery from the right sinus of Valsalva, with a markedly hypoplastic left circumflex artery and the presence of a 'superdominant' right coronary artery. Atherosclerotic lesions were not observed, and the symptoms were discussed to have been caused by the anomalous pattern of the coronary arteries and the hypoplastic left circumflex artery in particular. The most common symptom of a hypoplastic or absent left circumflex artery is chest pain on exertion which is explained by the 'steal' phenomenon - due to increased demand in the area normally supplied by the left circumflex artery, a transitory ischemia occurs in the basins supplied by the left anterior descending artery and the right coronary artery. These findings were similar to our case. Such variations, although mostly asymptomatic, can sometimes lead to serious cardiovascular conditions and should be considered by clinicians during the assessment of cardiac symptoms.

A Rare Case of an Azygos Lobe in the Right Lung of a 40-year-old Male.

The azygos lobe is a rare anatomical variant, most often encountered in the right lung. Its etiology is related to a defect of the migration of the azygos vein during the embryonic development. Here, we describe a rare case of an azygos lobe of the right lung, diagnosed incidentally on a computed tomography (CT) scan in a 40-year-old male patient who presented with chest pain, shortness of breath, and fever. The initial differential diagnosis included acute myocardial infarction, aortic dissection, and myocarditis. Chest CT with contrast matter demonstrated a peculiar finding in the right lung which was recognized as an azygos vein passing through the upper lobe and separating an azygos lobe with its mesoazygos. The azygos lobe may be rarely associated with neoplastic processes or spontaneous pneumothorax and its differential diagnosis on imaging studies includes various conditions. Knowledge of this variation is important to avoid misdiagnosis or complications during thoracic surgery.

Brachial Artery Coiling: Report of a Rare Case.

Nowadays, the transradial approach is increasingly used for performing percutaneous coronary interventions and is preferred over the transfemoral approach. In the latest European Society of Cardiology guidelines (2017) for management of acute myocardial infarction in patients presenting with ST-segment elevation, the transradial approach is recommended over the transfemoral one if performed by an experienced radial operator (MATRIX study). Transradial procedure failures may be related to puncture failure, artery spasm, or to anatomical variations that require specific catheter handling or changing with a contralateral or transfemoral approach. Herein we report a failure of transradial heart catheterization due to brachial artery coiling.

Palmaris Longus Muscle Variations: Clinical Significance and Proposal of New Classifications.

BACKGROUND: The palmaris longus muscle is one of the most variable muscles in the human body and there have been numerous variations reported. The different palmaris longus variations are interesting not only from an anatomical point of view, but they could also have definite clinical significance. AIM: The aim of this study was to examine the different types of variations of palmaris longus muscle in the Bulgarian population. MATERIALS AND METHODS: Over a period of 15 years, 56 formol-carbol fixed human cadavers were studied to investigate the different variations of palmaris longus muscle (PLM). RESULTS: Various anatomical variations of PLM have been reported: absence (2.68%); reversed palmaris longus coexisting with an additional abductor digiti minimi muscle (0.89%); digastric (0.89%); palmaris longus with intermediate muscle belly (1.79%) and duplication (1.79%). CONCLUSIONS: To reveal the wide variety of the types of palmaris longus muscle and their importance for clinical practice, we make a brief literature review concerning the different types of variations, their role in the median and ulnar neuropathy in the wrist or as structures simulating a soft tissue tumour and the application of palmaris longus tendon in plastic and reconstructive surgery as grafting material. We also present new systematic anatomical and clinical classifications of palmaris longus variations by dividing them into two simple groups.

A Case of Acute Left Main Coronary Obstruction Following Transcatheter Aortic Valve Implantation.

Transcatheter aortic valve implantation (TAVI) is a highly effective procedure in selected patients with severe degenerative aortic valve stenosis at high risk for conventional surgery. Coronary occlusion is a periprocedural life-threatening complication that despite its low frequency (˂1%) is poorly predictable and requires immediate diagnosis and treatment. Herein, we report a coronary obstruction after transcatheter implantation of valve prosthesis, followed by coronary intervention with successful recanalization.

Symptomatic Os Subtibiale Associated with Chronic Pain Around the Medial Malleolus in a Young Athlete.

An os subtibiale is a rare accessory bone located below or behind the medial malleolus. Herein we present a rare case of a painful os subtibiale in a young triathlete who presented with pain, redness and swelling below his left medial malleolus. Plain radiographs and three-dimensional computed tomography revealed a well-defined oval bone distal to the left medial malleolus. After conservative treatment failed, the ossicle was excised in an open surgery with complete resolution of symptoms. This case report emphasizes the need for clinical awareness of different anatomical variations of the bones of the foot.