Myoepithelial hamartoma of the rectum

Summary and Conclusions A review of medical literature has failed to disclose previous reports of myoepithelial hamartoma occurring in the rectum. The anomaly arises as a result of congenital aberration. The specific mechanism of development is unknown. Since malignant change has not been reported in myoepithelial hamartoma, local excision is adequate treatment. A case of myoepithelial hamartoma occurring in the posterior rectal wall of a 15-year-old girl is reported.     

CORYNEBACTERIAL PSEUDOTUBERCULOSIS IN MICE : I. COMPARATIVE SUSCEPTIBILITY OF MOUSE STRAINS TO EXPERIMENTAL INFECTION WITH CORYNEBACTERIUM KUTSCHERI

The susceptibility of mice to experimental infection with Corynebacterium kutscheri was studied by comparing the host response to this organism of mice obtained from 31 different colonies, representing 15 different genetic types. A standardized infective dose, administered intravenously, made it possible to separate the animals into two sharply differentiated groups. All the animals of the following colonies died: Swiss Lynch, Swiss R/J, A/Jax, Princeton, RFVL, and CF₁ (SPF). All the animals of the following colonies survived: CFW, ICR, Balb/C, BSVS, BRVR, RIII, YBR/He, DBA/2 (from 3 different colonies), and C57B1/6 (from 12 different colonies). The two highly inbred strains, Swiss Lynch and C57Bl/6, were selected as prototypes of susceptible and resistant animals respectively, for more detailed studies. Following injection of an infective dose of 0.2 x 10^–4 ml of culture of C. kutscheri, all Swiss Lynch animals died within 3 to 11 days (the majority within 4 to 7 days); whereas all C57Bl/6 animals survived. The outcome of the infection in each strain was independent of age and sex of the animals. In Swiss Lynch animals, the corynebacteria multiplied rapidly in lungs, liver, kidneys, and to some extent in the spleen. In C57Bl/6 mice, there was no increase of the corynebacterial population in the lungs, liver, or spleen, but multiplication occurred in the kidneys during the early phase of the infectious process with resultant abscess formation. However, the renal infection soon subsided leaving no residual pathology. C. kutscheri could not be recovered from any organs of C57Bl/6 mice sacrificed 16 days after infection. Homogenates of organs from Swiss Lynch mice obtained while the infection was progressing contained only typical C. kutscheri. In contrast, the lungs and livers of similarly infected C57Bl/6 animals occasionally yielded large numbers of small translucent colonies distinctly different from those of typical corynebacteria. The use of mouse strains differing markedly in response to experimental infection with C. kutscheri is presented as a biologic model lending itself to further studies concerning factors which condition resistance to corynebacterial pseudotuberculosis, a disease of practical importance for investigators conducting experiments with murine species.     

Transformation in vitro de cellules de hamster chinois par l'adénovirus 12: Étude cytogénétique

Chinese hamster cells can be transformed in vitro by adenovirus 12. These cells synthetise specific neo-antigen (s), are tumorigenic for this animal species and show chromosomal alterations which are independent of malignant conversion.     

Gastric Mucosal Energy Metabolism and “Stress Ulceration,”

Acute gastric erosions following hemorrhagic shock (stress ulceration) have been attributed to gastric hyperacidity, altered gastric secretion of mucus and an abnormal permeability of the gastric mucosa to H⁺. This report aims at presenting evidence supporting an alternate hypothesis: the event linking shock-induced gastric mucosal ischemia to mucosal necrosis is a deficit in gastric mucosal energy metabolism. Our experimental procedure consisted of harvesting the stomachs of rats and rabbits by “stop-freeze” (liquid N₂) at different intervals after the induction of hemorrhagic shock. Levels of adenosine-phosphates and of glycolytic intermediates in gastric mucosa were measured. We studied the changes in the levels of these substrates produced by shock as well as by factors capable, when combined with shock, of rendering the gastric mucosa more vulnerable to stress ulceration. The influence of shock and of these modifying factors were evaluated by comparison with data from appropriately designed control experiments. In parallel experiments we examined the frequency of stress ulceration (gross and microscopic) under these same standard conditions. There have emerged from these studies a number of observations all based upon data with the highest statistical significance. The data are consonant with the hypothesis stated above: an energy deficit severe enough to cause cellular necrosis is the event linking shock-induced gastric mucosal ischemia and stress ulceration.     

Effects of histamine on gastric blood flow

Summary In anesthetized dogs, volume flow rate of blood to the stomach and distribution of blood through the stomach were studied by means of an electromagnetic flow meter and a surface counting technic. Simultaneous measurements of gastric secretory activities were made. Histamine was found to decrease volume flow rate of blood to the stomach. Distribution of blood through the stomach was altered by histamine. Whereas under resting conditions distribution of blood flow was predominantly antral, during histamine-induced gastric hypersecretion, blood flow tended to shift toward the fundus and away from the antrum. Therefore, it appears that distribution of blood through the stomach is not uniform but is characterized by a borrowing and lending phenomenon.The work described in this article was supported in part by Grant A3934 from the National Institutes of Health and Grant E-186 from the American Cancer Society.Markle Scholar in Medical Sciences.     

Performance of a New Type of Blood Oxygenator

A new type of direct-contact oxygenator has been tested satisfactorily on dogs in nine experiments. It is based on the principle of the "packed column" and has the advantage of a small hold-up (meaning a small priming volume), no formation of foam, and gentle flowing of the blood. The apparatus is simple enough to be commercially available at a low price and discarded after use. Both PO₂ increase and PCO₂ decrease were satisfactory and plasma hemoglobin values remained low after 75 minutes of perfusion. Preliminary in vitro experiments on ox and human blood showed a low degree of blood damage.     

Sacral epithelioid angiosarcoma associated with a bleeding diathesis and spinal epidural hematoma: case report

Epithelioid angiosarcoma of bone is a rare, high-grade lesion that is highly vascular and can be associated with a bleeding diathesis. An association has been reported in angiosarcomas in other locations with coagulopathy from tumor-related disseminated intravascular coagulopathy and fibrinolysis. The authors report the case of a rare occurrence of a primary sacral epithelioid angiosarcoma associated with a large epidural hematoma and a severe bleeding diathesis. A 25-year-old woman presented with weakness, fatigue, neck and low-back pain, and progressive left S-1 radiculopathy. Imaging studies revealed a large ventral epidural hematoma extending from the sacral region rostrally to C-2 and a vascular tumor located in the sacrum. The patient underwent a sacral laminectomy, complicated by postoperative bleeding from the wound, and required massive transfusions. Ultimately, multimodal therapy was required to obtain hemostasis, including the use of endovascular embolization, radiation therapy, and an infusion of epsilon-aminocaproic acid with heparin. This case represents the first report of a primary epithelioid angiosarcoma in the sacrum and emphasizes that the coagulopathy seen in angiosarcoma is also a feature of this epithelioid variant.