Acidic and basic fibroblast growth factors delay the maturation of neural crest-derived neurons

Neural crest (NC) cultures were prepared from lumbosacral segments of 12 day rat embryos and maintained in a defined medium. Post-mitotic, flat, neurofilament+ neurons with broad neuritic processes ('nascent neurons') appeared within 24 h. Timing of the next stage in neuronal differentiation, the formation of bipolar, phase-bright cells that bound tetanus toxin with long, slender neurites ('bipolar neurons'), was markedly influenced by acidic or basic fibroblast growth factor (FGF). The transition from nascent to bipolar neuron occurred several days prematurely in medium without added FGF, but took place with a time-course like that in vivo when 10 ng/ml of acidic or basic FGF was added.     

Wire trapping in Rashkind's patent ductus arteriosus occluder: its etiology and how it may be avoided

Release of the Rashkind ductus umbrella may be complicated in that the central wire of the delivery catheter may become trapped within the foam of the umbrella. This problem occurs only if the central retaining wire is advanced when trying to disengage the catheter and umbrella. We propose a simple solution to the problem: Retract the sleeve instead of advancing the retaining wire.     

An unusual case of cystic chondroblastoma of the patella

An unusual case of chondroblastoma of the patella is presented in which the dominant feature was a hemorrhagic cyst. The chondroblastoma was located in a small gritty mass at one pole of the cyst, which could have easily been overlooked.     

Microcirculation of the lymph node with metastases

Microangiographic and histologic examination of the popliteal lymph node was performed on 49 rabbits 3 to 55 days after V2 tumor implantation into the hind paw. Control animals received subcutaneous tissue extract from normal rabbit donors. During the first 10 days after the tumor implant from an allogeneic animal donor, the draining lymph node exhibited a hypervascular response which after 2 weeks gradually subsided. Subsequently, during the early stages of lymph node metastasis there was still hypervascularity adjacent to the metastatic deposit. In about 4 weeks the metastases became more established and surrounded by layers of plasma cells. The hypervascular changes of the surrounding lymph node subsided by this time. In lymph node metastases the microvasculature could be an indicator of the immunologic activity of the host.     

Free, autologous, skin transplantation in the horse

Seven pieces of autologous skin were transplanted onto freshly created, full thickness skin defects on the limbs and back of a one-year-old, male, piebald, Shetland pony. The transplantations were completed in two operative sessions, the transplants on the left side were done in the first session and the right side in the second. The sizes of the transplants varied from 20 sq cm to 2 sq cm and their thicknesses from whole skin to very thin, split skin. Donor sites were both rumps and the right side of the neck. Six of the seven grafts and two thirds of the remaining graft, were accepted. Both whole thickness transplants grew hair, whereas no hair growth was detected at the 26th and 16th week following surgery on the split thickness transplants placed on the left and right sides respectively. The full thickness donor sites healed by granulation, contraction and epithelialisation. Healing at the split skin donor sites was rapid and uneventfull, epithelialisation being completed within one week and hair growth manifest by one month.     

The apexcardiogram in acute myocardial infarct

The relation between intracardial haemodynamics and apicocardiogram (ACG) parameters is explained. A wave (amplitude and duration), A/H ratio, true and total TCI, total systole, total expulsion, RIV, RFW, TE/TCI (total) and TE/TCI (true) findings in 22 patients with acute myocardial infarct are presented. Attention is also given to clinical and radiological signs of cardiac insufficiency and the infarct site. Constant and significant increases in the A wave, A/H ratio and RIV, together with a decrease in total expulsion, were noted, particularly in cases with clinical evident insufficiency. In the pre-expulsive stage, ACG Data could not be taken as a reliable index of myocardial contractility in cases where insufficiency was not manifest. It is felt, therefore, that ACG may be of assistance in the evaluation of changes in myocardial performance, even where clinical and radiological signs of decompensation are absent.