Stanley Kaplan

Experimental production of hypoplastic left heart syndrome in the chick embryo

Abstract The hypothesis is examined that hemodynamic alterations at the site of the primordial mitral valve may induce malformations that simulate the clinical findings of hypoplastic left heart syndrome. Surgical placement of a nylon device, approximately 90 μ in diameter, into the region of the left atrioventricular (A-V) canal was accomplished in 192 embryos (Hamburger-Hamilton stages 23 to 25). Thirty-nine pairs of experimental and control embryos survived more than 12 days. Twenty-six experimental embryos exhibited various malformations: hypoplastic left atrium and ventricle, mitral valvular atresia, aortic valvular stenosis and tubular hypoplasia of the aorta and brachlocephalic vessels. These findings reemphasize the probable morphogenetic role of blood flow pathways. The findings further implicate involvement of the left A-V canal as well as premature closing of foramen ovale and aortic valvular abnormalities in the hypoplastic left heart syndrome.

Response of the quiescent heart tube to mechanical stretch in the intact chick embryo

Abstract Quiescent heart tubes in intact eight-somite chick embryos were mechanically stretched by injecting excess fluid into the heart lumen. The stretch stimuli sometimes caused precocious focal twitches in the ventricular portion of the primitive heart tube. The contractile response to mechanical stretch was confirmed by recording electrograms before, during, and after the pressure pulse injections. The results prompt us to suggest that the precise timing of the initial heartbeats in the intact embryo may involve an increase in the intraluminal fluid volume and pressure stretching the heart tube wall.

Fast Green Staining Of Whole Embryos For Examination And Photography

Immersion for 15 seconds in a 1:1 solution of 0.25% fast green and 95% ethyl alcohol facilitates the examination of normal and abnormal embryos for gross surface morphology and renders their surface detail highly photogenic. The method does not interfere with subsequent histological staining when the embryos are sectioned.

Postmortem blood tests for HIV, HBV, and HCV in a body donation program

A retrospective analysis of the results of blood tests conducted on body donors received by the Anatomical Gift Registry of the Medical College of Wisconsin (MCW) was performed. Over the 5‐year period from April 1992 through March 1997 a total of 785 body donors were tested for Human Immunodeficiency Virus (HIV) and Hepatitis B and C Viruses (HBV and HCV). Eighteen of the 785 donors (2.3%) tested positive for one of these infectious agents. Two donors were positive for HIV, six were positive for HBV and ten were positive for HCV. The death certificates and files of those donors who tested positive were reviewed and the results are presented here. Blood testing prior to the use of the body donors is an effective and reasonable way of identifying the presence of these infectious agents, thus reducing the risk to those who work with cadavers. The cost for the testing at MCW is about

The antiteratogenic effects of hypo- and hyperthermia in trypan blue-treated chick embryos

60 per donor. Clin. Anat. 11:250–252, 1998.

Mechanical stress (shaking) and reticuloendothelial function in the chick embryo

Fertile White Leghorn chicken eggs (N = 174) were incubated under optimum conditions until the embryos had reached Hamburger-Hamilton stage 12 (about 48 hr). At that time, 20 μl of 1% trypan blue solution, dissolved in 0.85% NaCl (wt/vol) was injected through the yolk sac into the liquid yolk found just under the embryo. After injection, the eggs were separated into groups and returned to the incubator under control conditions (38°C), or at temperatures lower (35°C) or higher (41°C) than optimum. After an additional 24 hr of incubation, the embryos incubated at 35°C (N = 53) exhibited significantly fewer caudal hematomas (P < 0.02) than did embryos incubated at 38°C (N = 51). Similarly, embryos incubated at 41°C (N = 40) also exhibited significantly fewer caudal hematomas (P < 0.05) than did their corresponding (38°C) controls (N = 30). There was no significant difference between the 35°C group and their controls, or the 38°C group and their controls, in embryonic dry weight, dry weight of the area vasculosa, or crown-rump length. The only other significant difference detected between groups was a very slight but significant (P < 0.0005) decrease in Hamburger-Hamilton stage (0.4 stage unit) between embryos incubated at 35°C and the corresponding controls. Since incubation temperatures either above or below optimum result in a marked reduction in the teratogenic response to trypan blue treatment, we conclude that there exists a temperature optimum for the development of caudal hematomas.

Airport X-rays and floppy disks: no cause for concern

Abstract Stage 34 (8 day) and 41 (15 day) chick embryos were exposed (3 min) to two separate amounts of mechanical (shaking) stress. Eggs were shaken in the horizontal plane through their long axes. A laboratory shaker (Eberbach) was used to produce the stress and one complete excursion defined as carriage movement through 7.92 cm (3.96 cm in opposite directions). Reticuloendothelial system (RES) activity, as measured by colloidal carbon clearance (CCC), was evaluated following administration via an allantoic vein. Shaking stage 34 or 41 embryos at 100 excursions per minute (EPM) did not affect CCC; shaking them at 300 EPM resulted in an immediate and significant depression of CCC. Stage 41 embryos exposed to 300 EPM and reincubated for either 1, 2 or 4 hours prior to CCC determination reverted to control CCC values sooner than stage 34 embryos subjected to the same regimen. Functional RES response to mechanically induced stress has now been shown for the first time in an embryonic system (at two distinct developmental stages). The response appears to parallel that reported for various adult organisms. Furthermore, we suggest a temporal relationship regarding functional development of the embryonic RES.

Myocardial Metabolism after Collagen-Tube Revascularization of the Ischemic Heart: Experimental Study and Review of Literature*

A controlled study was done to test the possible effects of X-rays on the integrity of data stored on common sizes of floppy disks. Disks were exposed to doses of X-rays up to seven times that to be expected during airport examination of baggage. The readability of nearly 14 megabytes of data was unaltered by X-irradiation, indicating that floppy disks need not be given special handling during X-ray inspection of baggage.

Amphetamines reduce embryonic size and produce caudal hematomas during early chick morphogenesis

This study involved 6 dogs in which collagen tubes had been implanted in the left ventricle, while the right ventricle was left as a control. The dogs had led a normal life for twelve months after operation. Studies of myocardial metabolism, initiated a year after collagen‐tube revascularization, were performed as follows: Under anesthesia, samples of myocardium were taken from the left ventricle in which the left anterior descending coronary and circumflex coronary arteries had been ligated, and also from the right untreated ventricle. Oxygen uptake studies demonstrated that the myocardium of the treated ventricle respired at the same rate as that of the control ventricle, indicating that the revascularized tissue was efficiently perfused with blood and oxygen, that the cells of the revascularized myocardium were viable, and that the revascularization method would probably be adequate to maintain homeostasis in an ischemic heart.