Splenic Pseudocyst Associated with Hypersplenism

A patient with hypersplenism, who was found to have a splenic pseudocyst containing an organized hematoma, is described. There are only two patients with splenic pseudocyst and hypersplenism and an additional two patients with splenic cysts and hypersplenism reported in the world literature. The hypersplenism associated with splenic cysts and pseudocysts is explained on the basis of an expansion of the plasma volume and the total blood volume, an increased destruction of red blood cells and a pooling of blood in the enlarged spleen. The combined use of ultrasonography and computerized tomography has increased the accuracy of noninvasive diagnosis and made more invasive examinations unnecessary. When the ultrasound is technically unsuccessful or when it shows a mixed echo pattern, one should resort to computerized tomography with which it is possible, almost invariably, to differentiate between cysts and neoplasms.     

Plain Film Recognition of Giant Colonisc Diverticulum

Four cases of giant colonic diverticula are presented with emphasis on plain film recognition employing the "balloon sign", a persistent, rounded lucency which is consistently seen on any abdominal scout film or survey. The importance of this finding is even greater in the absence of gastrointestinal complaints in view of the complication of torsion and perforation     

Ectopic Gallstone as a Cause of Gastric Outlet Obstruction

Callstone ileus is, of course, a well known cause of small bowel obstruction. A gallstone, however, is a very rare cause of gastric outlet obstruction. Three cases illustrating this phenomenon are exhibited. Radiographs were diagnostic in two of the studies. All three patients did well postoperatively.     

Presence of an amphipathic helical segment and its relationship to biological potency of calcitonin analogs

The conformational properties of a number of calcitonin analogs were studied by circular dichroism. The ability of dimyristoylphosphatidylglycerol, lyso-phosphatidycholine or sodium dodecyl sulfate to induce the formation of more highly ordered structures in these peptides was also assessed by circular dichroism. In all cases sodium dodecyl sulfate induced the largest change in the circular dichroism spectra of the peptides. Salmon calcitonin and its analogs were slightly more helical in the presence of the anionic phospholipid than in the presence of the zwitterionic detergent lysophosphatidylcholine while the reverse is true for human calcitonin and its analogs. Some of the calcitonin analogs convert turbid suspensions of phosphatidylglycerol to a clear solution from which the phospholipid is no longer readily sedimentable by centrifugation. Several of the physical properties of these peptides could be correlated with their biological activity. Generally peptides which showed no hypo-calcemic activity had the least negative mean residue ellipticities at 222 nm. Only biologically active analogs were able quantitatively to solubilize dimyristoyl-phosphatidylglycerol and in this solubilized form the peptides have a higher helical content. More active derivatives exhibit larger increases in helix content in the presence of this phospholipid. Inactive analogs had the least negative mean residue ellipticities at 222 nm in the presence of lysophosphatidylcholine or sodium dodecyl sulfate. Thus, the ability of a calcitonin analog to form structures of higher helical content in the presence of amphiphiles is a requirement for the analog to exhibit high potency in assays of biological activity.     

Clinical Assessment of Gestational Age

There is disagreement among authors as to what criteria are most reliable in assessing postnatal fetal age. A comparison–for objectivity, accuracy, and frequency of use– of specific criteria was made using three independent examiners at different educational levels: a second-year medical student, a perinatal nurse practitioner, and a pediatrics resident. It was shown that trained examiners develop favorite criteria which differ among examiners and thus sacrifice accuracy; however, accurate assessment of fetal age can be accomplished by an examiner with minimum clinical knowledge.     

Origin of Pulmonary Megakaryocytes

1. Evidence is presented which indicates that pulmonary megakaryocytesdo not originate in the lungs but elsewhere in the body and are carried tothe lungs in the venous blood.

2. Some megakaryocytes in the lungs evidently deliver platelets to theblood.

3. Surgery is a potent stimulus to megakaryocyte production; the numbersof megakaryocytes found in the lung postoperatively is significantly increased.

Submitted on July 3, 1964 Accepted on September 19, 1964     

Heinz Body Anemia: An Ultrastructural Study. II. Red Cell Sequestration and Destruction

This study reports electron microscope observations on the process of redcell sequestration and destruction in the spleen and liver of the phenylhydrazine-treated rabbit. Damaged red cells are recognized by virtue oftheir Heinz bodies, a morphologic manifestation of the oxidative injury whichthey have sustained. Sequestration, in the spleen, involves the selective accumulation of damaged cells within the vascular spaces of the Billroth cords.Erythrophagocytosis and the intracellular digestion of red cells followssequestration. More severely injured cells may undergo intravascular hemolysiswithin the splenic red pulp. In the liver, however, no evidence for the intravascular sequestration of injured red cells is observed. Damaged cells areremoved directly from the sinusoidal blood by erythrophagocytosis. Theselectivity of spleen and liver for red cells subjected to different degrees ofinjury is discussed in terms of the observed differences in the vasculararchitecture of the two organs.

Submitted on November 15, 1964 Accepted on November 22, 1964