Biomedical subjects

A Schulman

Publications and source records attributed to A Schulman.

At least 127 records · Page 7Linked to original sources

PubMed1975

Composite materials for dental implants.

The requirements of endosteal dental implants are unique and stringent. The materials currently applied to implantation do not offer convincing evidence of satisfying these needs. This preliminary study reports on attempts at developing materials which would aid in obtaining a mucosal seal to maintain the integrity of the osseous, periosteal, and submucosal compartments from the oral environment and the attachment to bone as related to stress distribution. The materials that were under study were ceramic bonded to base metals and Dacron.

Aluminum↗

PubMed1975

The definition of radiological signs in gastric ulcer and assessment of their validity by inter-observer variation study.

The initial aim was to program a computer with information on the frequency of radiological signs in benign and malignant gastric ulcers in order to obtain a percentage probability of benignancy or malignancy in succeeding ulcers in clinical practice. However, only four of the many signs described in gastric ulcer were confirmed to be of validity (i.e. reliable existence) by an inter-observer variation study using two observers and the films from 69 barium meal examinations. These were projection or non-projection of the in-profile ulcer, presence or absence of adjacent mucosal folds, good or poor definition of the in-face ulcer's edge, and extension of radiating folds to the in-face ulcer's edge. A few more remained unassessed due to insufficient numbers of relevant cases. It is condluced that: as defined in the literature the majority of radiological signs in this field are of uncertain existence; and the four that were found to be valid do not fully describe the important appearances that may be seen in benign and malignant ulcers and would be inadequate to differentiate them to a sufficiently high degree of probability.

Diagnosis, Computer-Assisted↗

PubMed1975

The accuracy of radiological diagnosis of benign, primarily and secondarily malignant gastric ulcers and their correlation with three simplified radiological types.

Two radiologists individually gave 'blind' diagnoses of benignancy or malignancy to 145 radiographic representations of gastric ulcers, all with gastrectomy histological proof of benignancy or malignancy. A radiological diagnosis of malignancy was shown to be 98-6% reliable. A diagnosis of benignancy was less reliable (85-4% true positives) but this was a surgical series containing thereby an abnormally high proportion (over a third) of malignant ulcers. A correct diagnosis was mde in 99-5% of the proven benign ulcers, but in only 68-6% of the proven malignant ulcers. Analysis of the pathology reports on the malignant ulcers has shown that it was mainly those arising on the basis of pre-existing benign ulcers (i.e. secondarily malignant ulcers) that were wrongly diagnosed radiologically, thus suggesting that they have fundamentally different radiographic appearance from that of primarily malignant ulcers. It was then found that the ulcers could be divided into three simplified radiological types based on their in-profile appearances: type 1 (projecting), type 2 (intraluminal) and type 3 (so shallow as to be neither projecting nor intraluminal). Statistical association with the histological types led to the following conclusions: (a) radiological type 2 or 3 ulcers should be diagnosed as almost certainly malignant (usually primarily malignant) and (b) radiological type 1 ulcers are almost always benign but should be followed up until healed because the rare secondarily malignant ulcers are also usually of this type.

Diagnosis, Differential↗

PubMed1975

Urinary tract dilatation in pregnancy.

Two radiologists individually studied 220 intravenous urograms done during pregnancy in patients with apparently normal urinary tracts, and an observer-agreement technique was used to obtain the results. The few cases seen in early pregnancy show that dilatation of the urinary tract is uncommon, or at least mild, before mid term. Shortly thereafter, however, dilatation appears abruptly and remains virtually unchanged both in incidence and degree until full term. After mid term, the right side is dilated in about three-quarters of cases and the left side in about one-third. In only 10 % was the left side fuller than the right; in 86%, the right side was the fuller. Severe dilatation is infrequent, especially on the left. The dilatation never extends into the pelvis. The abdominal ureters are displaced outwards in a minority of cases, more often on the left. Little or no association was found between the dilatation and fetal position, maternal gravidity or urinary infection. These statistically derived conclusions should provide a firmer basis for what constitutes the limits of normality in the intravenous urogram during pregnancy.

Dilatation, Pathologic↗

PubMed1975

A new contrast medium for cholangio-cholecystography: meglumine iodoxamete.

A preliminary study of 18 patients following a single bolus intravenous injection of 10 to 30 cc. of meglumine iodoxamate (Cholovue), a new contrast medium for cholangio-cholecystography, showed no significant adverse clinical or laboratory effects with 10 to 20 cc., and only transient, minor changes with 30 cc. Early and persistent visucalization of the subsegmented and major bile ducts and the gallbladder was obtained. Good to excellent opacification was obtained in all cases with doses ranging between 0.11 cc./kg. (19.7 mg. iodine) to 0.59 cc./kg. (108 mg. iodine). Meglumine iodoxamate appears to be highly effective agent for cholangio-cholecystography.

Adolescent↗

PubMed1974