Tympanoplasty using homograft tympanic membranes and ossicles

The use of homograft materials in reconstructive, mastoid, and middle ear surgery is increasing. Not only are they useful and practical, but they also do the job well in both anatomical and functional restoration. Many encouraging reports have been written to support their use. Their advantages, in the opinion of the author, outweigh their cost since they can offer a more efficient, versatile, and better method of restoration of hearing in tympanoplasty surgery.     

Hydration characteristics and electrical resistivity of stratum corneum using a noninvasive four-point microelectrode method

We have used a four-microelectrode probe to study the relationship between electrical resistivity (p), water content (wf) water binding, and electrolyte levels in samples of plantar stratum corneum. Untreated samples characteristically showed an exponential relationship between log p and wf. This characteristic was retained but altered quantitatively by factors which increase and decrease the ratio of bound to unbound water, by lipid extraction, and (following extraction) by electrolyte presoak. The theoretical aspects of obtaining similar data from intact stratum corneum are discussed.     

Membranous basal cell adenoma of parotid gland, dermal cylindromas, and trichoepitheliomas. Comparative histochemistry and ultrastructure.

A basal cell adenoma of parotid, eccrine dermal cylindromas and trichoepitheliomas occurring in the same patient were examined by light and electron microscopy and histochemistry. The eccrine and parotid adenomas were similar both structurally and histochemically except for the presence of Langerhans cells in the cutaneous adenoma and well differentiated mucinous cells in the parotid tumor. The three different hamartomas found in this individual may represent the effect of a single pleiotropic gene acting on ontogenetically related stem cells.     

Comparison of the time course of the anorectic effect of fenfluramine and amphetamine with drug levels in blood.

Time courses of the suppressive effects on food intake of (+)-amphetamine and (plus or minus)-fenfluramine in deprived rats were found to be different. Amphetamine displayed a potent initial action which rapidly decayed, and this behavioural effect was consistent with the measured blood concentration of amphetamine which showed a peak at 1 h followed by rapid clearance. For fenfluramine, the initial suppression of eating was maintained over several hours and was, for the first hour, related to the blood concentration of fenfluramine but later to an active metabolite, norfenfluramine. The study shows how drug-induced changes in feeding behaviour fluctuate over time and illustrate how single measures of food intake may overlook information about the effectiveness of anorectic drugs.     

The prosthetic (Teflon) central aortopulmonary shunt for cyanotic infants less than three weeks old: results and long-term follow-up

The expanded microporous polytetrafluoroethylene (PTFE) 4 mm vascular prosthesis has been used to create a central aortopulmonary shunt in 20 critically ill infants less than 3 weeks old. The infants ranged from 1 to 18 days old (5.25 days), and from 1.5 to 4.0 kg (2.9 kg). Conduit length ranged from 2 to 6 cm (4 cm). Sixteen patients had atresia of the tricuspid or pulmonary valve. There were 6 early deaths (30%), only 1 of which was shunt related. The mean preoperative arterial oxygen saturation was 62% (range, 33 to 80%), and mean postoperative saturation was 87% (range, 78 to 90%). There were 5 late deaths, 1 probably caused by shunt failure. Nine long-term survivors have done well. Follow-up ranges from 1 to 36 months (18 months). Factors influencing conduit function are length, technical considerations, and pulmonary vascular resistance. Late restudy in 5 of 9 survivors confirms patency and demonstrates bidirectional pulmonary blood flow. Since PTFE shunt flow capability is fixed, the infant may require repair or a second shunt within 24 months of the initial procedure.