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Biomedical subjects

J H Gold

Publications and source records attributed to J H Gold.

17 recordsLinked to original sources
PubMed1979

Scaling current and energy with body weight: requirements for the transthoracic ventricular defibrillation of calves as they grow from 50 to 150 kg.

To test the hypothesis that the effectiveness of a shock in achieving ventricular defibrillation is relatively independent of body weight if electrode diameter is proportional to the one-third power and current is proportional to the two-thirds power of weight, we studied defibrillation rates in 10 calves as they increased weight. At 50 kg, each calf was subjected to 20 fibrillation-defibrillation episodes using 10.3-cm diameter electrodes and 32-amp, 4-msec rectangular pulses for defibrillation. Two days after the original study, each calf underwent 20 additional episodes involving 44-amp pulses. With the specified scaling of electrode diameter and pulse amplitude, the two studies were repeated at weight intervals of 25 kg as the animals grew. Six calves survived. In the study that started with 32-amp pulses, first-shock success values of 28%, 49%, 66%, 51% and 23% were found in the six surviving calves at 50, 75, 100, 125 and 150 kg, respectively. The corresponding values were 93%, 96%, 93%, 94% and 91% in the study that started with 44-amp pulses. While the results of the 32-amp study fail to support our initial hypothesis, those obtained in the 44-amp current study appear compatible with the hypothesis.

Animals↗
PubMed1979

University students and mental health. Canada, Britain and Singapore.

There are many crucial determinants of the individual outcome and benefit of a university education including the stressful interplay of cultural and socioeconomic factors which are of growing importance in the inflationary 1970's. An epidemiological study of university students from 1969-1972 in Canada, 1973-1974 in Britain, and 1975 in Singapore, attempted to identify stresses leading to mental ill-health in these students. Singapore was chosen as an example of a culture bridging the developed Northern and developing Southern nations of the world. Cultural differences affecting the results of the study are discussed as is the role of social change.

Adult↗
PubMed1979

Well-differentiated peripheral cholangiocarcinoma with an unusual clinical course.

A patient with an unresectable well-differentiated bile duct tumor who survived for 15 yr after biopsy diagnosis is presented. Histologic examination of the tumor revealed bland features of bile duct adenoma despite extensive spread within the liver. Over its subsequent course, the tumor progressively replaced the liver, achieving huge size, although there was no evidence of metastases until shortly before the patient's death. This clinical course was very unusual for either bile duct adenoma or cholangiocarcinoma, but would be more characteristic of another tumor of intrahepatic bile duct origin, the biliary cystadenoma. However, this latter diagnosis was excluded with both gross and microscopic pathologic criteria. Evidence is presented to support classification of this tumor as an unusual varient of peripheral cholangiocarcinoma which requires correlation of the clinical and pathologic findings for correst diagnosis.

Adenoma, Bile Duct↗
PubMed1978

Benign tumors of the liver. Pathologic examination of 45 cases.

The histologic and clinical features of 45 benign tumors of the liver (excluding hemangiomas) were reviewed. They included 21 cases of focal nodular hyperplasia, 11 cases of hepatic cell adenoma, 12 cases of bile-duct adenoma and a single case of mesenchymal hamartoma. By adhering to published histologic criteria, the cases of focal nodular hyperplasia and hepatic cell adenoma could be readily separated. Although both focal nodular hyperplasia and hepatic cell adenoma occurred predominantly in women, focal nodular hyperplasia occurred at a greater mean age, was usually asymptomatic, and the lesions tended to be smaller (surgical cases) than hepatic cell adenoma. The latter usually were symptomatic. It is emphasized that focal nodular hyperplasia and hepatic cell adenoma are distinct lesions and are separable on histologic grounds. Although the names focal nodular hyperplasia and hepatic cell adenoma are retained, the authors cannot assert that one lesion is a neoplasm, the other a reactive condition, and prefer, instead, to leave this question unresolved.

Adenoma, Bile Duct↗
PubMed1978

University students, mental health and development.

University students of the late 1960s and 1970s have been included in a study of factors affecting their mental health and academic functioning in many countries and cultures. Social change and intergenerational conflict were seen to be almost inseparable as social, economic and political concerns involve both students and their countries. Results of studies at Dalhousie University, six British universities, and the University of Singapore are examined in light of the socioeconomic problems existing at the time. High unemployment of university graduates, a growing factor in developing and developed nations, is pointed to as a major stress during a university education in the late 1970s.

Adolescent↗
PubMed1977

Transthoracic ventricular defibrillation in the 100 kg calf with unidirectional rectangular pulses.

The effectiveness in reversing ventricular fibrillation of 30 seconds duration of unidirectional rectangular-wave shocks having pulse widths of 0.5 through 64 msec, pulse amplitudes of 35, 50, 70, 100, and 140 amp, and pulse energies of 109 through 1,660 J was studied in 3,303 transthoracic fibrillation-defibrillation episodes in 100 kg calves. A total of 38 animals were used in the study. Postdefibrillation electrocardiograms were recorded. Families of curves of percent successful defibrillation vs pulse duration, percent successful defibrillation vs pulse energy, duration of postdefibrillation complete block or standstill vs energy, and time required for a return to normal sinus rhythm vs energy were derived. The most effective waveform studied (70 amp--8 msec--862 J) yielded defibrillation on the initial attempt in 93% of 120 episodes. In general, the duration of complete block or standstill and the time required for a return to normal sinus rhythm increased with increasing pulse current and pulse energy.

Animals↗
PubMed1976

Benign vaginal rhabdomyoma: a light and electron microscopic study.

A benign vaginal rhabdomyoma from a 49-year-old woman was examined by light and electron microscopy. While many of the ultrastructural features conformed to those noted in previously described rhabdomyomas, certain features are described for the first time. These include attachment plaques between cells enclosed within a common basement membrane, cytoplasmic bodies, and peripheral couplings. Finally, the literature is reviewed and the reported cases of rhabdomyoma are divided into adult and fetal types based upon light microscopic criteria.

Cell Nucleus↗
PubMedDate not supplied

Meningeal mycosis fungoides: cytologic and ultrastructural aspects.

Mycosis cells were identified in the pre-morbid cerebrospinal fluid of a patient with neurological symptoms and mycosis fungoides (MF). Light and electron microscopic examination at autopsy confirmed leptomeningeal involvement by mycosis fungoides. The cellular morphology of the non-cutaneous infiltrates supports the concept that mycosis fungoides retains a unique histopathology in its dissemination to the viscera. The importance of cerebrospinal fluid cytology in patients with mycosis fungoides is emphasized.

Brain Neoplasms↗
PubMedDate not supplied

Design of an ultrahigh-energy hydrogen thyratron/SCR research defibrillator.

The design features of an ultrahigh-energy research defibrillator are described. Three voltage sources are used. The first is a 60-Hz supply of adjustable amplitude and duration for inducing fibrillation. The second source uses an 18.000-joule capacitor bank which can be charged to 800, 1600, or 2400 volts. SCRs in series with the chest are used to initiate the discharge, and SCRs shunting the capacitor bank terminate the discharge. The third source employs another 18,000-joule capacitor bank which can be charged to 5000, 10,000 or 15,000 volts. In this source, large ceramic-enveloped hydrogen thyratrons are used for both initiating and terminating the discharge. In the second and third sources, which can deliver rectangular, trapezoidal, truncated exponential, or untruncated exponential waveforms, capacitor charge time is 10 sec and the duration of the delivered shock is continuously adjustable from 100 musec through 1 sec.

Animals↗
PubMedDate not supplied

Comparison of transthoracic square-wave defibrillation experience in the dog and calf.

Data from 5,280 fibrillation-defibrillation episodes in medium-size dogs, size scaled to a hypothetical 100-kg dog, and from 3,240 episodes in 100-kg calves, are used to derive families of curves showing percentage of success of unidirectional square-wave pulses in achieving defibrillation versus current amplitudes for energy levels in the range of 200 through 2,000 J. From the 3,240 episodes in the calves and 3,240 additional episodes in dogs, the incidence of post-defibrillation complete A-V block was found. In calves, the optimal 800-J curve peaks sharply at about the 93 percent success level for a current amplitude of 70 A. For the hypothetical dog, the 800-J curve has a broad peak at substantially the 100 percent success level for currents of 40 through 120 A. In general, the incidence of complete A-V block is very low in the dog and very high in the calf.

Animals↗