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Biomedical subjects

A Shapiro

Publications and source records attributed to A Shapiro.

264 records · Page 15Linked to original sources
PubMedDate not supplied

Calculated neutron dose rates and flux densities from implantable californium-252 point and line sources.

The results of neutron-transport flux-density and dose rate calculations for implantable Californium-252 point and line sources in essentially infinite tissue-equivalent material are presented. The point-source flux densities were obtained from a discrete ordinates calculation, and the point dose rates were established by multiplying the flux densities by their appropriate kerma factors. Line-source dose rates were evaluated by integrating the point dose rates over the length of the line source. Dose-rate data are given within a 20 X 20-cm region from the source center for source lengths of 1.5, 2, and 3 cm. The dose rates established by these calculations showed good agreement with an independent Monte Carlo calculation. Detailed point-source flux-density data as a function of energy and position are also given.

Californium↗
PubMedDate not supplied

Measured neutron and gamma spectra from californium-252 in a tissue-equivalent medium.

A method of experimentally obtaining both neutron and gamma-ray spectra in a scattering medium is described. The method utilizes a liquid-organic scintillator (NE-213) coupled with a pulse-shape discrimination circuit. This allows the separation of the neutron-induced pulse-height data from the gamma-ray pulse-height data. Using mathematical unfolding techniques, the two sets of pulse-height data were transformed to obtain the neutron and gamma-ray energy spectra. A small spherical detector was designed and constructed to reduce the errors incurred by attempting spectral measurements in a scattering medium. Demonstration of the utility of the system to obtain the neutron and gamma-ray spectra in a scattering medium was performed by characterizing the neutron and gamma-ray spectra at various sites about a 3.7-microgram (1.5 cm active length) californium-252 source in a tissue-equivalent medium.

Californium↗
PubMedDate not supplied

Activated recombinant human coagulation factor VII therapy for intracranial hemorrhage in patients with hemophilia A or B with inhibitors. Results of the novoseven emergency-use program.

Activated recombinant human coagulation factor VII (rFVIIa) is a promising new therapeutic agent for patients with hemophilia A or B with inhibitors who experience serious bleeding episodes or who need coverage during surgical procedures. This open-label, uncontrolled, emergency-use study evaluated the efficacy and safety of rFVIIa in 11 hemophiliac patients and 1 FVII-deficient patient with life-threatening intracranial hemorrhage previously unresponsive to one or more alternative therapies. rFVIIa effectively controlled intracranial hemorrhage in 10 of the 12 patients. Patients with hemophilia A or B received an average of 96.9 rFVIIa injections over 14.7 days with a mean total administration of 153.3 mg, corresponding to 8.1 mg/kg. Most reported adverse events were considered to be unrelated to rFVIIa therapy. These findings suggest that rFVIIa is an effective and well-tolerated therapeutic option in the management of central nervous system bleeding in patients with hemophilia A or B with inhibitors.

Adult↗
PubMedDate not supplied

Visual functions following bilateral surgery of congenital cataracts in children.

The visual functions, before and after surgery, of 19 children with bilateral congenital cataract are evaluated. Some of the children, in spite of the poor vision before surgery and the late age at surgery, developed good vision with binocular functions. These children probably had an incomplete lens opacity in their early childhood which became completely opaque at an age at which irreversible stimulus deprivation amblyopia is unlikely to develop. Therefore, children over the age of 6 years with poor vision due to congenital cataract, on whom no information is available concerning the density of their lens opacities in early childhood, should not be regarded as having a poor visual prognosis.

Adolescent↗
PubMedDate not supplied

Successful repair of combined renal pedicle injury: a new application of the ex vivo "bench" technique.

A case of avulsion injury to the renal pedicle caused by blunt trauma in a 22-year-old man is reported. Mild peritoneal irritation, microscopic hematuria, a nonsecreting left kidney on intravenous pyelography, and an intimal tear of the left renal artery were demonstrated on renal angiography and suggested an injury to the pedicle of the left kidney. Explorative laparotomy revealed minor lacerations of the ileal mesentery and an intimal tear of the renal artery with complete transection of the renal pelvis in its intrarenal portion. The combined vascular and ureteral injuries were repaired by the ex vivo "bench" technique. The kidney was reimplanted into the left iliac fossa. Intravenous pyelography performed one month postoperatively revealed an immediate secretion of the left kidney. One year later the patient was normotensive, with good function of the reimplanted kidney. This is the first reported application of the ex vivo "bench" technique and autotransplantation of the kidney to the iliac fossa in a trauma case.

Adult↗
PubMedDate not supplied

Screening for prostate cancer.

In an attempt to detect prostate cancer when the tumor is still confined to the prostate, a screening program was established. We studied the efficacy of digital rectal examination (DRE) and serum prostate-specific antigen (PSA) in the early detection of prostate cancer. One thousand men aged 50-75 years underwent DRE and serum PSA determination. Transrectal ultrasound-guided biopsies were obtained in each case of a suspicious DRE. Six systematic biopsies were performed if the PSA level was > 10 ng/ml, even if DRE and transrectal ultrasonography revealed no areas suspicious of cancer. A suspicious DRE was noted in 11.5% of the subjects; 16% had elevated levels of serum PSA (> 4 ng/ml) and 3.9% had serum PSA > 10 ng/ml. Biopsies were obtained from 90 patients, of which 31 were positive for prostate cancer. The cancer detection rate was 2.2% for DRE, 2.0% for PSA > 10 ng/ml, and 3.1% for the two methods combined. Clinical staging revealed that in 29 of the 31 patients with prostate cancer, the tumor was confined to the prostate: Stage A in 9 cases and stage B in 20 cases. Only two patients had clinically advanced cancer, and 22 patients underwent radical prostatectomy. Pathological examination disclosed biologically significant tumors in 91% of the cases in terms of tumor volume and grade. Although there is little evidence that screening will result in the reduction of the disease-specific mortality rate, early detection of prostate cancer by DRE, serum PSA, and transrectal ultrasound should be encouraged.

Aged↗