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Biomedical subjects

H Nathan

Publications and source records attributed to H Nathan.

At least 19 recordsLinked to original sources

Recipient race does not influence waiting time for a cadaveric renal transplant--one organ procurement organization's experience.

There was no statistical significance to the differences in waiting time for cadaveric renal transplant by race. Whether for first transplant or second or greater, any differences in waiting time could not be accounted for by the recipient's race. CAUC made up 58% of the waiting list, 65% of the recipients, and 87% of the donors. The corresponding numbers for AA are: 38%, 29%, and 10%, respectively. More regional serum-sharing trays may be needed in order to expose recipients with high PRA to as many donors as possible in order to lessen their waiting time. It should be noted that fewer HLA mismatches occurred when donor and recipient race were identical. In light of this data, more study is needed to determine the relationship between donor and recipient race, corresponding HLA mismatches, and graft survival. If antigen-matching is found to increase graft survival, then an increase in minority donations will be required. Until that time, under the current allocation system and with the predominance of Caucasian donors, it is likely that Afro-Americans will continue to receive kidneys that have more HLA antigen mismatches than if Afro-Americans donated in numbers equivalent to their percentage of the waiting list.

Adult

Impact of a required request law on vital organ procurement.

"Mandatory" or required request for donation of the organs of patients dying in hospitals has been promulgated as a means of increasing the rate of organ harvest and alleviating the critical shortage of transplantable organs. Although the federal and many state governments have passed legislation to make such requests compulsory, the efficacy of this approach has not been demonstrated. Examination of the experience at our trauma center and in this region, before and after the enactment of a "strong" required request law by the State of New Jersey, did not reveal a statistically significant change in organ procurement. We conclude that such laws are unlikely to achieve the desired result in the absence of fundamental changes in the attitudes of the public and treating physicians.

Age Factors

Failure to predict intraoperative myocardial ischaemia in patients with coronary artery disease.

Patients with severe coronary artery disease were studied to determine if the preoperative assessment or intraoperative haemodynamic monitoring could predict the occurrence of myocardial ischaemia. Thirty-eight patients undergoing coronary artery surgery who had normal electrocardiograms before induction of anaesthesia were included. Leads II and CS5 were recorded on a Holter monitor and radial arterial and pulmonary artery catheters were used to measure haemodynamic variables. Eight patients developed ST-segment changes greater than or equal to 0.1 mV before sternotomy. Preoperative factors could not be used to predict which patients would develop ST-segment changes. In all 38 patients haemodynamic determinants of myocardial oxygen supply and demand remained within an optimal range despite evidence of ischaemia in eight. This syndrome of ECG changes in the absence of tachycardia and hypertension resembles the syndrome of silent ischaemia documented in awake patients. Our findings suggest that myocardial ischaemia may be caused by decreases in coronary blood flow not associated with changes in haemodynamic variables.

Adult

The inguinal region: anatomic differences in men and women with reference to hernia formation.

Fifty inguinal regions were dissected in anatomic human adult specimens, of which 26 were males and 24 females. The comparison of anatomic variations in both sexes showed that the distance between the public tubercle and the internal ring was larger, and the rectus muscle significantly wider in females. The diameter of the internal ring was larger in males, however, with significant variability. No differences were found regarding the presence or absence of the conjoint tendon. The anatomic variations may explain the sex differences in hernia formation.

Anatomy

Germ cell tumors of the testicle or 'orchidomata'.

An unusual case of a double testicular tumor, with different histology and the same marker chromosome, led to a search of the literature for cases of testicular tumors that were double, bilateral, or familial. The literature on abnormal chromosomes in tumors of the testis is also reviewed. After a discussion of the facts, it is suggested that most of the histological variants of germ cell tumors of the testicle are so closely related that they could be grouped together under the title of 'orchidomata'.

Chromosome Aberrations

The pterygo-spinous muscle--an aberrant (atavic) remnant.

We report here on an aberrant pterygoid muscle found during a dissection of the infratemporal fossa. We have not noted such a muscle in hundreds of dissections in the area. A few anatomical texts (Piersol, 1911; Testut, Latarjet, 1931) have referred to its possible existence as the pterygo-spinous muscle.

Adult

Relations of the soft structures of the posterior mediastinum in the scoliotic spine.

In 20 dissections of scoliotic cadavers, the changes of the structures in the posterior mediastinum in relation to the spine were found to be as follows. The aorta persistently followed and adhered to the abnormal curves of the spine. The azygos vein and the thoracic duct followed the aorta closely in its changes. The sympathetic trunk and the greater splanchnic nerves likewise followed the changes in the curvature of the scoliotic spine, but they were often disturbed in their course by vertebral osteophytes and by hyperostoses due to arthritis of the costovertebral joints. The esophagus preserved its normal straight course, unaffected by the scoliotic curves.

Cadaver

Medial and lateral arcuate ligaments of the diaphragm: attachment to the transverse process.

According to current anatomy textbooks, the diaphragmatic medial and lateral arcuate ligaments are attached to the transverse process of the first lumbar vertebra. In dissections of 15 human cadavers we found both arcuate ligaments attached to the transverse process of L2 (10 cases and L3 (5 cases). In no case were they attached to the transverse process of L1.

Diaphragm

Anatomical observations on the mylohyoid groove, and the course of the mylohyoid nerve and vessels.

In a study of 390 mylohyoid grooves in dry mandibles and in dissections of the region, the groove conformed to the classic description (that is, it was open along its entire length) in only 83.6% of the cases. In the remaining 16.4%, the sulcus was partially or totally converted to a bony canal by ossification of the membrane that covered it. When only partially converted, the ossification was proximal or distal, single or multiple. This ossification is explained according to the embryological origin of the membrane closing the canal from Meckel's cartilage. The practical importance of these observations in anatomical dissection and in surgical intervention in the region is discussed.

Humans

Changes in the mechanical properties or rat tail tendon during postnatal ontogenesis.

The ultimate tensile strength, elasticity modulus and ultimate elongation of tail tendon in rats age 1-18 months were measured with an Instron tensile apparatus. An increase in all these parameters was observed during the period of maturation, with a later levelling off of the tensile strength and the ultimate elongation. The value of the elasticity modulus attained a maximum during sexual maturation, and then decreased and stabilized.

Age Factors

Anatomical observations of the foramina transversaria.

Four hundred and eighty foramina transversaria in dry cervical vertebrae of 36 spines and in a number of dissections were studied and classified according to size, shape, and direction of their main diameter. A coefficient of roundness was then elaborated. The variations of foramina appear to follow a pattern at various vertebral levels. The possible factors (in addition to the embryological ones) involved in causing these variations-for example, mechanical stress, size, course, and number of vertebral vessels-were analysed. The importance of the correct interpretation of the variations in the foramina transversaria in radiographic or computerised axial tomography is discussed. The contribution of the present study to the understanding and diagnosis of pathological conditions related to the vertebral artery and its sympathetic plexus is stressed.

Adult