A comparative morphometric study of the myocardium during the postnatal development in normotensive and spontaneously hypertensive rats.

BACKGROUND: Differences in the size of cardiac muscle cells observed in normal and hypertrophic hearts have been assessed through different methodologies. Spontaneously hypertensive rats are often used as an experimental model of essential hypertension in humans, which allows researchers to study the relation between hypertension and cardiac hypertrophy. It has been shown that ventricular hypertrophy in mammals progresses and ventricular failure develops in the end stage of hypertrophy. The aim of the present study was to analyse a number of morphometric markers and compare them between male normotensive Wistar rats (WR) and male spontaneously hypertensive rats (SHR). MATERIALS AND METHODS: The total number of male WR was 15, distributed in five age groups, each containing three animals: 2-week-old; 1-month-old; 3-month--old; 6-month-old; 12-month-old. The male SHR were distributed in two age groups, each containing three animals: 1-month-old (young) and 6-month-old (adult). RESULTS: As aging progressed, both in male normotensive WR and in male SHR we noted a statistically significant increase in the morphometric parameters thickness of the free wall and the cross-sectional area of the cardiomyocytes and their nuclei and a decrease in the cardiomyocytic density in both ventricles. These changes were more pronounced and occurred at an earlier age in SHR. CONCLUSIONS: The present study analyses in detail the alterations in the myocardium of the left and right ventricle, initiated by age-related hypertrophy, as well as hy-pertrophy induced by arterial hypertension. (Folia Morphol 2018; 77, 2: 253-265).

Unusual coexistence of a variant abductor digiti minimi and reversed palmaris longus and their possible relation to median and ulnar nerves entrapment at the wrist.

During routine anatomical dissection of the left upper limb of a 73-year-old female cadaver, a unique coexistence of variant muscles was found. In the forearm region, a largely developed reversed palmaris longus was discovered. Its short distal tendon was in close relation to the median nerve. In the neighboring hypothenar region, an unusual abductor digiti minimi was also observed. Its muscular body was composed of two portions - medial and lateral one, arising from the reversed palmaris longus tendon. The lateral portion passed over the ulnar nerve and artery in the canal of Guyon. In the literature, there are descriptions of entrapment neuropathies caused by either reversed palmaris longus or variant abductor digiti minimi. Here, for the first time we describe a coexistence of these variant muscles and suggest it as a possible, even rare, cause of both the median and ulnar nerves entrapment and ulnar artery thrombosis.

Unusual high-origin of the pronator teres muscle from a Struthers' ligament coexisting with a variation of the musculocutaneous nerve.

During routine anatomical dissection of the right upper extremity of a 53-year-old woman cadaver, an unusual high-origin of the pronator teres muscle was discovered. The fibers of the aberrant muscle arose from two bone origins--the medial epicondyle and a small supracondylar process of the humerus, and from a tendinous arch (Struthers' ligament) extending between them. In addition, there was a variation of the musculocutaneous nerve--in the axilary fossa the musculocutaneous was fused to the median nerve and its usual branches arose consecutively from the median nerve stem. The last of these branches--the lateral antebrachial cutaneous arose in the lower part of the arm from the median nerve and companion to it and to the brachial artery passed under the Struthers' ligament. Our findings indicate that in some rare cases of combined muscular-nerve variations, the lateral antebrachial cutaneous nerve can be added to the neurovascular structures possibly entrapped by the Struthers' ligament.

Radial artery coursing behind the biceps brachii tendon: significance for the transradial catheterization and a clinically oriented classification of the radial artery variations.

In routine clinical practice the variations of the radial artery are the main reason for technical failure during transradial catheterization. If these variations are well documented, however, they do not represent a problem in the transradial approach. Therefore, we report here a rare case of the radial artery which is very strange but potentially valuable for the clinical practice: it arises at a right angle from the brachial artery and passes behind the biceps brachii tendon. Based on our findings and on an extensive literature review, we propose for the first time a clinically oriented classification of the variations of the radial artery. This classification is related to the catheterization success at the usual access site of the radial artery at the wrist.

A novel simple technique for en face endothelial observations using water-soluble media -'thinned-wall' preparations.

A new, easily applicable technique providing en face preparations for light microscopy observations of the rat aorta and human thin wall arteries is described here. The major steps of the technique include attachment of the fixed and flattened vessel with the endothelium face down on a glass slide, covered with a water-soluble adhesive medium; drying and softening the vessel wall with another water-soluble medium; removal of the adventitia and most of the media; detaching the layer by placing the glass slide in water; and final attachment of the layer with the endothelium upwards. On such 'thinned-wall' preparations, 40-50 microm in thickness, the stained endothelial cells are clearly visible. Because of the preparation thickness and the use of water-soluble media during the preparation, some subendothelial lipid accumulations, characteristic of the early stages of atherosclerosis process, are well preserved.

Axillary arch in human: common morphology and variety. Definition of "clinical" axillary arch and its classification.

In this work the authors summarize the extensive information available concerning the best-known variant muscular structure in the region of the human axilla--the axillary arch. Emphasis has been placed on the common morphology and variety of the axillary arches. From the anatomical descriptions, the authors extract the characteristics of a group of "typical" axillary arches and also noted the descriptions of a group of "unusual" axillary arches found in the recent literature. The axillary arch terminology, incidence in human population, innervation and origin are discussed. The clinical significance of the axillary arch is presented briefly and the need of a new concept for the axillary arch is stated. In conclusion, for the purpose of clinical practice, a new term--"clinical" axillary arch is defined, and its proper clinically oriented classification is presented.

Undescribed variant muscle--"deep abductor-flexor" of the little finger, in relation to ulnar nerve compression at the wrist.

During routine anatomical dissection in the hypothenar region of the left hand of a 64-year-old female cadaver, a number of variant structures were observed. The most prominent finding in our case was a supernumerary muscle hitherto unknown in the anatomical literature. This variant muscle had a muscular body formed by the connection of two deeply situated muscular bellies--medial and lateral. The lateral belly originated from the flexor retinaculum, the medial one--from the hamate bone. The common muscular body inserted to the antero-lateral surface of the base of the fifth proximal phalanx. Due to its location and possible function, we named the variant muscle "deep abductor-flexor" of the little finger. The flexor digiti minimi brevis muscle showed two proximal tendons--the medial tendon was attached to the hamulus of the hamate bone while the aberrant lateral tendon originated from the lateral part of the flexor retinaculum. Both, the aberrant lateral tendon of the flexor digiti minimi brevis and the lateral belly of the "deep abductor-flexor", passed over the palmar branch of the ulnar nerve, which define their possible clinical significance in ulnar nerve compression. Therefore, the variations of the hypothenar muscles are reviewed and their relation to the compression of the ulnar nerve is discussed.

Axillary arch in Bulgarian population: clinical significance of the arches.

In order to study the incidence of the axillary arch in the Bulgarian population, we examined the axillary regions of 56 formol-carbol fixed human cadavers and observed two cases with a unilateral axillary arch. In the first case, the variant structure was situated on the right side of a 58-year-old female cadaver. The axillary arch extended from the lateral border of the latissimus dorsi to the posterior layer of the pectoralis major tendon. In the second case, the axillary arch was found on the left side of a 63-year-old male cadaver and had the same attachment points as in the first case. The innervation and blood supply of the arches are discussed. We have also reviewed extensive information concerning the clinical importance of the axillary arch, and for the first time, it was summarized clearly for clinicians. The summary consists of three parts: "diagnosis" of the axillary arch by physical investigation or imaging techniques; the axillary arch and surgical interventions in the region of the axilla; the axillary arch as an entrapment site for the axillary vessels and nerves.

Study of variant anatomical structures (bony canals, fibrous bands, and muscles) in relation to potential supraclavicular nerve entrapment.

Since the definition of supraclavicular nerve entrapment syndrome by Gelberman et al. (Gelberman et al. [1975] J. Bone Joint Surg. Am. 57:119) a number of clinical cases of this specific entrapment neuropathy have been reported. In all these cases, the nerve injury has been attributed to the location of the supraclavicular nerve branch in a narrow canal in the clavicle. However, in the anatomical literature, variations in the course of the supraclavicular nerves have not only been ascribed to bony canals but also to abnormal fibrous and muscular structures. Considering the fact that the existence of a narrow site with rigid walls along the course of a nerve is essential for the development of an entrapment neuropathy, our study examines all the variant anatomical structures with a possible role in supraclavicular nerve entrapment. We describe three groups of anatomical structures with close relation to the course of the supraclavicular nerves-transclavicular canals, fibrous bands, and unusual muscular structures. Based on the characteristics of the variations found, for the first time, we suggest that in addition to the bony canals through the clavicle certain fibrous and muscular structures could also be an anatomical basis for supraclavicular nerve entrapment syndrome.

Bilateral variations of the psoas major and the iliacus muscles and presence of an undescribed variant muscle--accessory iliopsoas muscle.

Inspite of the detailed description of the iliopsoas muscle complex, interesting variations of its main parts--the psoas major and the iliacus muscles can still be encountered. These variations may clarify some aspects of the embryological development of the iliopsoas and have certain clinical importance because of the frequent co-existence with an unusual femoral nerve by its formation and course. We present in our report a case of bilateral variations of the psoas major and the iliacus muscles combined with variations of the left and the right femoral nerves, which were found during the anatomical dissection of a female human cadaver. The most remarkable finding was noted on the left side, where an undescribed variant muscle accessory iliopsoas, was observed. It was the only finding of such a muscle among 108 human cadavers examined over a period of 22 years. The accessory iliopsoas was formed by the connection of two accessory muscles--accessory psoas major and accessory iliacus. The clinical significance of the described variant muscles and their importance as an additional factor in the femoral neuropathy are also a matter of discussion in our report.

Lack of inferior thyroid artery.

In the present study, a case of a cadaver is reported in which variations of some branches of both subclavian arteries occur. Among the most impressive findings is the lack of the right inferior thyroid artery combined with an abnormal ramification of the right superior thyroid artery, the terrace-like course of the left inferior thyroid artery and variations in the course of the prevertebral segment of both vertebral arteries with a high entry into the transverse cervical foramen of one of them. A morphometric description of the arterial variations has been carried out and their possible significance for the surgical and diagnostic practice is outlined.