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Biomedical subjects

M Hirsch

Publications and source records attributed to M Hirsch.

At least 181 records · Page 10Linked to original sources
PubMed1977

Ultrastructure of the blood-aqueous barrier in normal condition and after paracentesis A freeze-fracture study in the rabbit.

There is in the ciliary epithelium a barrier which prevents the passage of plasma proteins into the posterior chamber of the eye. The anatomical site of this blood-aqueous barrier is at the zonulae occludentes (tight junctions) located between the lateral plasma-membranes of the nonpigmented epithelial cells. Using the freeze-fracture technique we have studied these junctions in the pars plicata. As in many epithelia, they are formed by an anastomosing network of ridges on the fracture PF face and by a complementary set of furrows on the fracture EF face of plasma membranes. Features of these junctions are the presence of frequent parallel and closely associated double or triple ridges, and a few small gap junctions, associated with tight junctional elements of the zonulae occludentes. We also show that the number of junctional strands (ridges and furrows from apex to base) varies from a few strands to about 15, according to their position around the nonpigmented epithelial cells. These observations suggest that the rabbit's ciliary epithelium is to be classified among the 'tight' or 'very tight' epithelia (Claude and Goodenough, 1973). After paracentesis, we observed no breakdown of the zonulae occludentes. This supports the hypothesis that the site of leakage of the plasma proteins is elsewhere than ciliary epithelium.

Animals↗
PubMed1977

Congenital cysts of the head of the pancreas.

A very rare case of an infant with a huge multilocular congenital cyst of the head of the pancreas is presented. The symptomatology, diagnosis and surgical approach are discussed, while reviewing the few scattered reports in the English literature. Selective celiac arteriography is considered to be of definite aid in the differential diagnosis of cystic lesions of the head of the pancreas and has important implications on the choice of surgical procedure. We believe this to be the first case of a congenital cyst of the head of pancreas to be diagnosed accurately preoperatively by means of selective celiac and gastroduodenal angiography. Cystoduodenostomy proved to be a simple and effective procedure.

Angiography↗
PubMed1977

The Dyggve-Melchio-Clausen syndrome.

Two families with Dyggve-Melchior-Clausen syndrome are reported. In the first family, Jews from Morocco, six of 10 siblings are affected. In the second family, a consanguineous marriage of Arabs from Gaza, two of three children are affected. A description of the skeletal changes in patients ranging in age from 4 to 25 years is presented. The radiologic signs of generalized platyspondyly with double humped end plates and the lace-like appearance of thickened iliac crests are pathognomonic and distinctive of the syndrome. The diagnostic features of the disease are compared to those of Morguio's disease, spondyloepiphyseal dysplasia tarda, and spondylometaphyseal dysplasia.

Adolescent↗
PubMed1977

Renal vein thrombosis as the major cause of renal failure in familial Mediterranean fever.

Eighteen out of 57 patients (31-6 per cent) suffering from Familial Mediterranean Fever (FMF) were found to have the nephrotic syndrome, histologically proven amyloidosis and progressive renal failure. In 14 cases renal function deteriorated rapidly after the first appearance of significant proteinuria, and 12 cases (66-7 per cent) required regular haemodialysis. Seven of these patients, seen in the early stages of renal impairment, were subsequently diagnosed clinically as probably having developed renal vein thrombosis. There was radiological proof of intrarenal or major renal vein occlusion in five which in one patient progressed to inferior vena cave obstruction. Treatment with heparin, plasminogen activators and fibrinogenolytic agents was disappointing although renal function has stabilized in one patient on long term oral anticoagulant therapy. It is suggested that renal vein thrombosis is common in FMF with renal amyloidosis and usually causes rapid deterioration of function and irreversible renal failure requiring dialysis. Renal phlebography may delineate clot in the main renal veins or indicate areas of reduced blood flow due to thromboses in intrarenal venules. Treatment is only partially satisfactory but there is some evidence to suggest that renal phlebography should be undertaken promptly when renal function begins to fall followed by anticoagulant therapy to prevent further thromboembolic complications.

Acute Kidney Injury↗
PubMed1976

Neonatal pulmonary hypoplasia after prolonged leakage of amniotic fluid.

The clinical, radiological, and pathological features of the 'oligohydramnios tetrad' (Potter's facies, limb malpositions, pulmonary hypoplasia, and growth retardation) resulting from chronic amniotic fluid leakage are described in 2 infants who died of respiratory failure within 12 hours of delivery. A third infant with a partial form of the syndrome had prolonged respiratory symptoms and survived the neonatal period: the course of the disease and the radiological findings were compatible with a hypothetical diagnosis of partial pulmonary hypoplasia. Pulmonary hypoplasia should be recognized as a cause of chronic respiratory symptoms in viable infants.

Abnormalities, Multiple↗
PubMed1976

Left ventricular diverticulum and mitral incompetence in asymptomatic children.

Two children with congenital apical left ventricular diverticulum and significant mitral incompetence are reported. The angiographic and anatomic findings of the few previously reported patients with congenital diverticula and aneurysm were analyzed and a new classification differentiating between the two is proposed. The clinical data analyzed in apical diverticula and aneurysm are similar to those patients with anomalous origin of the left coronary artery from the pulmonary artery. Left ventriculography is the best diagnostic tool. The place of surgery in the treatment of the congenital apical diverticula with or without mitral incompetence in asymptomatic children is not clear. Further observations are needed to reveal its natural history.

Angiocardiography↗
PubMed1976

The influence of oestradiol-17beta and progesterone on the contractility of the oviduct of the turtle, Chrysemys picta, in vitro.

The contractility of the oviduct of Chrysemys picta (the fresh-water turtle) was studied in vitro. Significant regional differences in contractile activity were observed. Contractions increased in amplitude and duration and decreased in frequency from the proximal to the distal end of the oviduct. Injections of oestradiol-17beta in vivo increased the amplitude of contractions and decreased the duration of the rest period in segments taken from the diatal end of the oviduct. In contrast, progesterone injections significantly reduced the duration of both contractile and resting periods.

Animals↗
PubMed1976

[Ciliated cells of corneal endothelium. Functional and morphological aspects compared to cilia of other organs].

The presence of ciliated cells has been demonstrated by scanning and transmission electron microscopy in corneal endothelium. This study has been carried out on human cornea in normal and pathological cases and on rabbit's normal cornea. Another study has been lead on regeneration of endothelium after freeze destruction. The cilia cells described have a normal structure. The cilia has nine peripheral groups of tubules without any tubule in the center. The cilia seem to be more numerous in case of corneal disease and during the regeneration of corneal endothelium. The authors compare the presence of ciliated cells in different tissues. This suggest that the potency to form single cilia is present in almost every kind of tissue but there is no proof of their pathological importance. In the corneal endothelium, as in the kidney, cilia seem to have no function of fluid transportation but the possibility for cilia to be a receptor is discussed.

Animals↗
PubMed1976

[The use of freeze-etching in the ultrastructural study of the cornea].

The freeze-etching and freeze-fracturing techniques allow a good examination of fixed and unfixed tissues by the mean of transmission electron microscope. As compared with usual techniques of fixed and embedded tissues we can observe the ultrastructural characteristics of the rabbit cornea: epithelium, stroma and endothelium. This technique is the best one to give a good view of the intercellular junctions. 1) On the epithelial layers we describe intracytoplasmic bunches of filaments and numerous desmosomes. After freeze-fracturing the desmosomes appeared to be formed of aggregated particles on fractured faces. These particles are possibly the point of attachment of intracytoplasmic tonofibrils.

Animals↗
PubMed1976

Aplasia of toe phalanges and nails.

An infant born without toenails and without the middle and distal phalanges of the toes was otherwise normal, on clinical and radiological examination. This is the second case of this entity to be described. It is speculated that an environmental insult at the critical period of fetal toe development may be the cause of the anomaly, but a genetic factor cannot be excluded.

Adult↗
PubMed1975

Bilateral nephroblastomatosis.

Bilateral nephromegaly with a histological picture of diffuse Wilms' tumor or so-called bilateral nephroblastomatosis is a rare condition. We present an additional case documented by urography. To our knowledge, this is the first report of diffuse nephroblastomatosis recognized at 2 hours of age. A few cases are reported but urographic documentation is available in only 4 of those and in our own. The review of the urographic findings reveals features which seem seem to be nearly pathognomonic of this condition. Urographic appearance similar to that of adult type polycystic disease without the typical radiolucent cysts, should raise the suspicion of a diffuse bilateral process in the kidneys. Exclusion of other infiltrative diseases, like leukemia and glycogen storage disease, should lead to radiologic diagnosis of nephroblastomatosis. Renal biopsy is then indicated.

Humans↗
PubMed1975

Delayed hemopericardium following penetrating foreign body into the aorta.

A four and a half year old girl with delayed appearance of traumatic hemopericardium, detected radiologically despite misleading clinical manifestations, is presented. The presence of cardiomegaly and a needle in the right upper mediastinum on the chest roentgenogram and its partial motion together with diminished cardiac pulsations at fluoroscopy led to angiocardiography. The radiological demonstration of hemopericardium due to the needle penetrating the aortic root, enabled successful surgical intervention.

Aorta↗