Biomedical subjects

J W Shaffer

Publications and source records attributed to J W Shaffer.

At least 37 records · Page 2Linked to original sources

PubMed1987

Experimental vascularized bone grafts: histopathologic correlations with postoperative bone scan: the risk of false-positive results.

A positive bone scan in an experimental model of bilateral ulna diaphyseal bone grafts demonstrated early bone repair in both vascularized and nonvascularized orthotopic ulna autografts. A positive bone scan did not correlate with the perfusion of the vascularized and nonvascularized grafts as measured by microangiograms done 1 week postoperatively. In this model, if the bone scan is intended to monitor the circulatory status and viability of the bone graft, it must be done earlier than 1 week postoperative prior to the onset of creeping repair in both vascularized and nonvascular ulna autografts.

Animals↗

PubMed1987

Clustering of personality traits in youth and the subsequent development of cancer among physicians.

Using 14 personality measures obtained while the subjects were in medical school, the resulting profiles of 972 physicians were clustered into five groups using a two-stage cluster analysis procedure. Subjects were followed over a 30-year period to determine the cumulative survival rate (proportion of subjects remaining free of cancer) in each group. Statistically significant group differences in survival rate were found, with the group characterized by acting out and emotional expression having the most favorable curve (less than 1% developing cancer). The group characterized as "loners," who may well have suppressed their emotions, had the most unfavorable survival curve and was 16 times more likely to develop cancer than was the group characterized by acting out and emotional expression.

Follow-Up Studies↗

PubMed1987

Multiplicity of neurilemomas in the upper extremity.

Multiple neurilemomas in two patients show that these tumors may indeed be multiple, may involve the same nerve trunk, may occur over a period of years, and may involve different regions of the body. Twelve neurilemomas were removed from the right upper extremity of a patient over a 3-year period. They varied in size from 0.5 cm to 4 cm in diameter and had the typical histopathologic appearance of neurilemomas. The second patient had median nerve compression and at operation a neurilemoma was found compressing the nerve. Two years later, the patient had evidence of median nerve compression in the opposite extremity, and again a neurilemoma was found. Both of these patients had evidence of peripheral nerve compression, but the existence of multiple neurilemomas was not apparent on initial examination. These cases show that patients with neurilemomas may have additional sequential tumors discovered at a later date that were not apparent initially.

Aged↗

PubMed1987

Effects of halothane, enflurane, and isoflurane on somatosensory evoked potentials during nitrous oxide anesthesia.

The effects of 0.5, 0.75, and 1 MAC of halothane, enflurane, and isoflurane in 60% nitrous oxide on somatosensory cortical evoked potentials were studied in 30 patients undergoing corrective surgery for scoliosis. The evoked potentials were averaged at the scalp from the electroencephalogram following repeated bilateral posterior tibial nerve stimulation at the ankle. Latencies and amplitudes of the resulting potentials were measured and compared with the post-induction control values. Graded increase in latencies and graded decrease in amplitudes were found with increasing concentrations of all the three agents (P less than 0.05), confirming that the effects were dose related. Reductions in amplitudes were more marked than increase in latencies. The authors conclude that, during nitrous oxide-based anesthesia, enflurane, and isoflurane resulted in less alteration of somatosensory cortical evoked potentials than halothane. In conjunction with 60% nitrous oxide, 0.5 and 0.75 MAC of halothane, 0.5, 0.75, and 1.0 MAC of isoflurane and enflurane, respectively, were found to be compatible with the generation of waves adequate for evaluation.

Adolescent↗

PubMed1987

Attitudes toward narcotic addiction.

In an effort to isolate the major dimensions of attitude and expectation regarding narcotic addiction and its treatment and to compare different groups of addict/clients and agency staff on these factors, a comprehensive questionnaire was administered to 900 addict/clients and 237 agency personnel in 25 drug treatment clinics in six states. Results of a factor analysis, which used questionnaire data from all of the 1137 subjects so that direct group comparisons could be made, indicated the presence of 10 major dimensions of attitude and expectation. Results also suggested considerable variation, particularly by status (client vs. staff) and ethnic group, on these dimensions. An additional analysis of staff attitudes and expectations revealed correlations with years of education, ex-addict status, and years of work experience. Such findings suggest the need to consider client/staff characteristics and attitudes in the planning of treatment services for narcotic addicts. An abbreviated (53-item) attitude and expectation questionnaire was developed for this purpose.

Adult↗

PubMed1987

The relationship of preaddiction characteristics to the types and amounts of crime committed by narcotic addicts.

Postaddiction crime rates among narcotic (principally heroin) addicts in five different areas (theft, violence, dealing, confidence games, and other crime) were found to be substantially related to a number of preaddiction characteristics, especially criminal activity and drug and alcohol use prior to addiction to narcotics. Early family influences such as lack of religious training, history of parents' arrest, and use of drugs and alcohol by other family members also appear to play an important role. Early identification of extremely crime-prone individuals followed by intensive intervention efforts might reduce the amounts of crime such persons might otherwise commit.

Adult↗

PubMed1987

Biology of vascularized bone grafts.

Vascularized canine fibular autografts demonstrated improved biologic and mechanical characteristics 3 months after surgery when compared with nonvascularized controls. The vascularized proximal fibula maintained its overall architecture without bony collapse or significant bone turnover. The strength and stiffness of these grafts were approximately 40 per cent and 56 per cent more than nonvascularized grafts, respectively.

Animals↗

PubMed1987

The use of urokinase in ischemic replanted extremities in rats.

UNLABELLED: We compared the efficacy of intra-arterial infusion of urokinase, a fibrinolytic agent, with that of intra-arterial infusion of nitrendipine, a peripheral calcium-channel blocking agent, in preventing the no-reflow phenomenon in rats after prolonged ischemia at room temperature. Urokinase increased the survival of the limbs after both four and five hours of ischemia at room temperature to 100 per cent compared with 50 and 20 per cent, respectively, in untreated controls. Nitrendipine significantly increased the blood flow but failed to significantly increase the survival of the limb. Scanning electron microscopy was used to assist in the evaluation of the endothelium of the vessels. The etiological mechanism of the no-reflow phenomenon appears to be that ischemia damages the endothelial cells, causing impairment of the fibrinolytic system, retraction of the endothelial membrane, exposure of the subintimal collagen, and fibrin-platelet deposition. Thrombosis of the vessels ensues, resulting in the no-reflow phenomenon. CLINICAL RELEVANCE: Experimentally, intra-arterial infusion of urokinase increased the survival of the limb in replanted extremities that were subjected to ischemia. This effectively lengthened the safe limit of ischemia at room temperature before microsurgical replantation or elective free-tissue transfer. Clinical trials of the use of intra-arterial fibrinolytic agents for the treatment of revascularized tissue are indicated.

Animals↗

PubMed1986

A possible relationship between figure drawing data collected in medical school and later health status among physicians.

Figure drawings obtained while subjects were in medical school were scored using two different scales: (a) Sophistication-of-Body-Concept, a scoring system that measures the overall quality of the drawings; and (b) Conventionality/deviancy of the drawings, as determined by the relative frequency with which 42 different characteristics occurred in the total sample of drawings. Figure drawings were obtained from 1951 to 1964. As of 1984, subjects were classified into 1 of 11 health outcome (disease) categories plus a "healthy" category. Statistical analysis included one-way analyses of variance and multiple logistic regression in which age and cigarette consumption were controlled. Several statistically significant differences among groups were noted with respect to Conventionality/deviancy, but not with respect to Sophistication-of-Body-Concept.

Adult↗

PubMed1986

A comparison by ethnic group and city of the criminal activities of narcotic addicts.

In an effort to update the results of earlier studies concerning the amounts and types of crimes committed by urban, male narcotic addicts, confidential interviews were conducted with addicts attending methadone maintenance clinics in Baltimore and New York. Samples were stratified by ethnic group (black and white in Baltimore; black, white, and Hispanic in New York), and the amounts and types of crimes committed were compared across groups, cities, and narcotic addiction status (actively addicted/not actively addicted) using six different measures all based on the concept of crime-days per year at risk. Consistent with previous findings, addicts were found to engage in a great deal of criminal activity, especially during periods of active addiction to narcotics. Differences in the amounts and types of crimes committed were found among ethnic groups and, to a lesser extent, between cities as well. For the Baltimore sample, comparison of findings with those derived from an earlier (1973-78) data base suggests that the amount of crime committed by addicts has increased in several categories as well as overall. However, minor differences in data collection procedures render this finding suggestive rather than conclusive.

Adult↗

PubMed1986

Inpatient diagnoses during Adolf Meyer's tenure as director of the Henry Phipps Psychiatric Clinic, 1913-1940.

Between 1936 and 1950, detailed abstracts were prepared on all patients admitted to The Phipps Psychiatric Clinic from its opening in 1913 through 1950. Of these abstracts, 74% contained follow-up reports. Except for four papers on schizophrenia and affective disorders published between 1939 and 1943, none of this material has ever been analyzed. The present paper, the first of a series, examines the 8172 first admissions from 1913 through 1940, the period of Adolf Meyer's tenure as Clinic Director. Based on discharge diagnoses, we have sorted the patients into eight diagnostic groups with the following frequencies; schizophrenia, 17%; paranoid state, 3%; manic-depressive, 7%; depression, 27%; organic, 20%; neuroses, 15%; substance abuse, 6%; psychopath, 5%. Our manic-depressive group contains cases discharged primarily as hyperthymergasia, mania, or manic depressive insanity (MDI). Of the 349 cases diagnosed MDI at discharge, 10 had neither a history of nor present symptoms of mania, and these were put in the depression group. Frequencies for most of the diagnoses remained remarkably stable over the 28-year period. Only 9% were discharged recovered, whereas 43% were rated unimproved. Mean length of hospitalization was 76 days, with 10% of the patients readmitted. The mean length of follow-up was 9 years. Correlations of diagnoses, year of admission, length of stay, condition at discharge, age, sex, readmissions, change of diagnoses, somatic treatment, length of follow-up, and deaths in the clinic are presented. Meyer's influence on diagnostic practice is discussed.

Biological Psychiatry↗

PubMed1986

A comparison by race/ethnicity of narcotic addict crime rates in Baltimore, New York, and Philadelphia.

In an effort to provide timely information concerning the criminal activities of narcotic addicts in three different metropolitan areas, male narcotic addicts attending methadone maintenance/detoxification centers in Baltimore, Philadelphia, and New York City participated in extensive, confidential interviews conducted between May 1983 and April 1984. The information obtained focused on the amounts and types of crimes committed during the addict's longest period of active addiction to opiates, their derivatives and synthetics, as well as his first period of nonaddiction. Crimes committed were placed in one of five categories as follows: Theft, Violence, Drug Sales, Deception/Forgery, and Other. Several different measures of criminal activity were utilized, all embodying the concept of crime-days per year at risk. Such crime-days measures involve annualizing, i.e., the number of crime-days accumulated by each subject in each category during a specified time at large in the community is expressed as crime-days per year at risk by taking the ratio of crime-days to total days at large and multiplying by 365. Addicts were compared by race/ethnicity (Black, White, and Hispanic) within cities as well as by race/ethnicity across cities using one-way analysis of variance procedures. Addict crime rates were also compared for the period of active addiction and nonaddiction. Several mean differences by race/ethnicity within city, as well as by race across cities, were noted. Moreover, crime rates tended to be higher during the period of active addiction. In this sense, then, drugs may be said to "drive" crime.

Adult↗

PubMed1985

Bone grafting: role of histocompatibility in transplantation.

The role of histocompatibility matching in bone allografting was studied in two canine bone graft models. In a cancellous ulnar segmental replacement model, frozen bone allografts exchanged between closely matched dogs were significantly better incorporated by radiographic and histologic criteria than were strongly incompatible grafts. Frozen allografts from disparate donors in recipients receiving immunosuppression appeared indistinguishable 6 months later from those in the untreated closely matched groups and from fresh autografts. Fresh vascularized orthotopically placed fibular bone grafts were evaluated by quantitative blood flow assessment, microangiography, and fluorochrome histomorphometry. Revascularized grafts exchanged between untreated closely matched dogs demonstrated preservation of blood flow and a pattern of repair that was delayed but not otherwise different than vascularized autografts. These results suggest that fresh vascularized grafts in the judiciously matched or immunosuppressed recipient offer attractive clinical possibilities.

Animals↗

PubMed1985

An ischemia-induced model of revascularization failure of replanted limbs.

Twenty-five amputated rat hindlimbs were replanted after various periods of warm ischemia. The incidence of limb failure that was due to the no-reflow phenomenon was found to be 0% after 2 or 3 hours of warm ischemia, 50% after 4 hours, and 80% after 5 hours of ischemia. Predictors of the occurrence of no-reflow were the presence of an increased number of venous red blood cell aggregates 5 minutes after replantation, the slope of the tissue pH curve that was recorded for 1 hour after replantation, and assessment of hydrogen washout flow to the foot pad. All limbs had excellent flow immediately after revascularization. The marked difference in flow that was detected 1 hour after replantation between the limb survival group (n = 16) and the limb failure group (n = 9) suggests an ongoing obstructive process. In those limbs that were successfully replanted, an 18% increase in femoral artery flow was found after revascularization compared with a 20% decrease in flow to the muscle and a 3% decrease to the foot pad. This supports the concept that arteriovenous shunting occurs after replantation. The presence of microthrombi that adhere to the vessel wall after replantation correlated well with limb failure. Our observations support ongoing arterial obstruction, arteriovenous shunting, and an altered thrombogenic-fibrinolytic system as factors that may be responsible for the no-reflow phenomenon.

Animals↗

PubMed1985

The criminality of narcotic addicts.

Recent research conducted by independent investigators concerning the relationship between crime and narcotic (primarily heroin) addiction has revealed a remarkable degree of consistency of findings across studies. The major conclusion supported by the majority of these studies is that narcotic addicts commit a vast amount of crime and that much of this is directly related to the need to purchase drugs. A large proportion of the crimes committed does not consist merely of drug sales or possession, but involves other criminal behaviors including serious crimes. The strongest evidence of a causal relationship between narcotic drug use and crime is derived from longitudinal studies in which the amount of crime committed during periods of active addiction far exceeds that committed during periods of nonaddiction. Much of this crime goes unreported, although addicts, under conditions of strict confidentiality, have provided information that permits realistic estimates of criminal activity. Use of this methodology has permitted the identification of different types of addicts, especially with respect to the amounts and types of crimes in which they are engaged. The implication of these findings is that although addicts as a group commit a great amount of crime, they cannot be regarded as a homogeneous class. Some addicts commit many crimes, regardless of current addiction status, whereas others commit relatively few, and these are obviously related to their need to purchase drugs. There is a discernible impact of treatment on narcotic drug use and criminality. Although the relationships between addict characteristics and treatment response have yet to be fully determined, extensive prior criminal involvement is associated with a negative outcome.

Crime↗

PubMed1985

Segmental spinal instrumentation in idiopathic scoliosis. A preliminary report.

Eighty-six patients with idiopathic scoliosis who underwent a posterior spinal fusion using sublaminar segmental spinal instrumentation were analyzed retrospectively. There were two operative groups: group 1, 66 patients who had Harrington rod instrumentation and segmental wiring, and group 2, 20 patients who had Luque rod instrumentation. The clinical and radiographic data of the two groups were similar except for the passage of more sublaminar wires and increased intraoperative blood loss in group 2. Twenty intraoperative or postoperative complications occurred in 19 patients (22%) including 14 neurologic complications. Three patients (3%) had major spinal cord injuries, while 11 patients (13%) had transient sensory changes. There was no significant difference in the incidence of neurologic complications between group 1 or group 2. The remaining intraoperative complications were due either to anesthesia, positioning during surgery, or technique (dural tear). Late complications occurred in two patients in group 1 only: one each with rod breakage and hook displacement. Only one patient (1%) has required additional surgery. Our results indicate that although segmental instrumentation can be beneficial in idiopathic scoliosis, the incidence of complications, primarily neurologic, will be higher than expected. The major reason appears to be surgeon inexperience with passage of sublaminar wires. As experience increases, the incidence of complications declines and becomes comparable with conventional Harrington rod instrumentation alone.

Adolescent↗

PubMed1984

A vascularized fibula model to study vascularized canine bone grafts.

We have refined the experimental canine vascularized fibula model in 26 dog experiments. Our results have demonstrated that both periosteal and endosteal blood flow are retained following end-to-end anastomosis of the bone graft pedicle artery and vein. The success of this model depends on detailed knowledge of the surgical anatomy and upon meticulous microvascular surgical technique.

Animals↗

PubMed1984

The effect of redundancy and tension on microvascular vein grafts.

Variation in length and tension occurs with microvascular vein grafts in clinical practice. The length and tension of a vein-grafted segment was varied in 50 Sprague-Dawley rats. This enabled a full range of redundancy and tension across the 1 mm diameter vein grafts. The initial patency rate was 100%. Wounds were reexplored 2 weeks after operation. A linear increase in microaneurysm formation was found with increasing tension. There was a mild but not statistically significant observed effect on patency. Increasing tension in rat vein graft anastomosis has an adverse effect with an increased incidence of microaneurysm formation and should be avoided.

Aneurysm↗