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Biomedical subjects

L L Anderson

Publications and source records attributed to L L Anderson.

At least 73 records · Page 4Linked to original sources
PubMed1996

Cutis laxa acquisita associated with multiple myeloma: a case report and review of the literature.

Cutis laxa acquisita is a rare disorder that affects collagen and elastin metabolism. The cause is unknown. Characteristic features include sagging and laxity of the skin, as well as involvement of the lungs, heart, gastrointestinal system, and urogenital tract. Three cases of cutis laxa acquisita have been reported in association with multiple myeloma. Due to the rarity of these disorders, a linkage has been postulated. The clinical and histologic data from the fourth case of cutis laxa acquisita associated with multiple myeloma were compared to the three other cases previously reported in the literature. The relationship between acquired cutis laxa and multiple myeloma is unclear, with only one case revealing possible immune-mediated elastin destruction via IgG immunoglobulin bound to dermal elastin fibers on immunofluoresence examination. No pattern in the clinical courses of the disorder can be seen on review of the four cases with coincident disease. We hypothesize that cutis laxa acquisita represents a paraneoplastic process of multiple myeloma, given the rarity of these diseases. Further investigation is necessary to determine the underlying linkage between these disorders. We suggest that serum and urine protein electrophoresis results be obtained in patients presenting with cutis laxa acquisita to screen for multiple myeloma given this association.

Antineoplastic Agents↗
PubMed1995

The relative biological effectiveness of I-125 and Pd-103.

PURPOSE: To determine the relative biological effectiveness (RBE) of I-125 and Pd-103 relative to Co-60. METHODS AND MATERIALS: A cell line REC:ras, derived from rat embryo cells, was used. Cells in exponential or plateau phase were irradiated at dose rates of about 0.07 Gy/h and 0.14 Gy/h. To circumvent the interface effect, cells were grown and irradiated on membranes made of cellulose acetate, which has an effective Z of 7.5. I-125 and Pd-103 seeds were placed in a custom designed template that yielded a homogeneous dose distribution in the plane of the cell culture. The dose rates of irradiation were measured by calibrated thermoluminescence dosimetry (TLD) chips. RESULTS AND CONCLUSIONS: Our measurements yielded an RBE of about 1.4 for I-125 at dose rates of about 0.07 Gy/h, and an RBE of about 1.9 for Pd-103 at dose rates of about 0.07 Gy/h and 0.14 Gy/h. The RBE of I-125 is similar to those measured by other investigators, the RBE for Pd-103 is being reported for the first time.

Animals↗
PubMed1995

Chromosomal localization of the human prostanoid receptor gene family.

Prostaglandins (PGD2, PGE2, PGF2 alpha, and PGI2) and thromboxane A2 (TXA2) are biologically active molecules derived from the metabolism of arachidonic acid by cyclooxygenases. They produce a wide variety of physiological and pathophysiological effects mediated through specific G protein-coupled cell surface receptors. In this study, we have mapped the chromosomal positions of the human genes that encode the PGE2 receptor subtypes (PTGER1, PTGER2, and PTGER3), the PGF2 alpha receptor (PTGFR), the PGI2 receptor (PTGIR), and the TXA2 receptor (TBXA2R) using in situ hybridization. The PTGER1, TBXA2R, and PTGIR genes mapped to chromosome 19 at positions 19p13.1, 19p13.3, and 19q13.3, respectively. The PTGFR and PTGER3 genes mapped to chromosome 1 at positions 1p31.1 and 1p31.2, respectively, and PTGER2 gene mapped to chromosome band 5p13.1.

Chromosome Mapping↗
PubMed1995

Opioids modulate progesterone production in prepubertal Bunaji heifers.

The opioid antagonist naloxone was administered to prepubertal heifers, and its effects on progesterone, cortisol, and LH secretions were studied. Pooled pretreatment values in peripheral plasma for progesterone averaged 0.26 +/- 0.08 ng/ml (+/- SE), and those for cortisol averaged 13 +/- 1.2 ng/ml. Naloxone treatment at either 1.1 (Nal-1) or 2.0 (Nal-2) mg/kg BW significantly increased circulating progesterone within 15 min of i.v. injection, which was sustained for 45 and 75 min, respectively. Maximal progesterone concentrations were 1.8 +/- 0.16 ng/ml and 1.8 +/- 0.19 ng/ml at the low and high naloxone dosages; progesterone values were basal by 120 min. Naloxone caused a dose-dependent increase in plasma cortisol averaging 20 +/- 3.1, 28 +/- 4.2, and 49 +/- 5.7 ng/ml in the immediate 120 min posttreatment in control, Nal-1, and Nal-2 heifers, respectively; but naloxone injection, at either the low or the high dosage, had no effect on plasma LH concentration. The effect of naloxone on progesterone concentration was dependent on the age and body weight of the animal; it was first observed at 28 mo of age and between 130 and 160 kg BW. None of the heifers that showed transient elevations in progesterone exhibited estrous behavior or had a palpable CL throughout the study. These coincident transient increases in circulating progesterone and cortisol demonstrate that an endogenous inhibitory opioidergic system is involved in the control of steroid hormone secretion in prepubertal zebu heifers. Further, an adrenal source of this progesterone is indicated, but whether the progesterone participates in the induction of an LH increase in the prepubertal heifer is not clear.

Animals↗
PubMed1995

Surgical wound healing complicated by Aspergillus infection in a nonimmunocompromised host.

BACKGROUND: An unusual complication of cutaneous surgery and its management is presented. Aspergillus flavus was identified from a nonhealing surgical wound of the ear undergoing cartilaginous necrosis in an immunocompetent host. OBJECTIVE: We wish to alert clinicians that Aspergillus may infect surgical wounds of the ear causing significant morbidity. METHOD: A healthy man underwent Mohs micrographic surgery for invasive Bowen's disease of the ear. Due to the size and location of the defect it was allowed to heal by secondary intent. The patient developed inflammation and subsequent destruction of the ear cartilage. Aspergillus was demonstrated by touch preps and cultured from swabs and tissue from the necrotic wound. RESULTS: In spite of aggressive topical and oral antifungal therapy severe distortion of the pinna occurred, resulting in surgical removal of the upper two-thirds of the ear. CONCLUSIONS: In the presence of cartilage necrosis following surgery on the ear, Aspergillus infection should be considered. Early aggressive management with surgical debridement, and topical and oral antifungal therapy may prevent destruction of the cartilage and a significant cosmetic defect.

Aspergillosis↗
PubMed1995

Controlled mold geometry for surgical deficit treatment planning.

The relatively precise placement of brachytherapy sources afforded by stereotactic frames for brain implants is not generally achievable for other sites, which lack the fixed geometry of the cranium and its contents. An exception is a source-containing rigid mold that delivers brachytherapy when inserted securely in a surgical defect. A technique has been developed in which an acrylic mold of the region to be treated is suspended in a demountable aluminum box, which is then filled to a suitable level with dental stone to form a casting that supports the mold and that can be removed intact. First, the box is aligned on a mill table and a ball mill is used to drill three parallel holes in the acrylic mold, with precisely known locations and depths and as widely separated as possible. The spherical air cavities that result from plugging these holes with ball-milled acrylic rods become reference markers in subsequent computed tomography (CT) scans. After optimum CT-coordinate locations have been planned for 125I seeds in catheters, they are transformed to mill coordinates using a matrix developed from the known marker coordinates in the two systems. Catheter holes are then drilled with the mold in the reassembled casting and box. The method has been used to treat both recurrent maxillary cancer and recurrent orbital rhabdomyosarcoma.

Biophysical Phenomena↗
PubMed1995

Mifepristone (RU 486) induces parturition in primiparous beef heifers and reduces incidence of dystocia.

Crossbred beef heifers (n = 21) were artificially inseminated and on d 268 (expected parturition = d 283) heifers were fitted with an indwelling jugular catheter for sequential blood sampling from d 270 to 278. Heifers were assigned randomly to three treatment groups (n = 7) on d 277: Group 1 received the synthetic steroid mifepristone (RU 486) alone, Group 2 received RU 486 plus relaxin, and Group 3 received placebo treatment. Parturition occurred 43 h after treatment in Group 1, 52 h in Group 2, and 182 h in Group 3, and hormone treatment reduced treatment-to-calving interval compared with diluent treatment (P < .01). Calf birth weights were lower in hormone-treated than in placebo-treated heifers (P < .025), but all calves were vigorous at birth. The incidence of dystocia was lower (P < .05) in heifers in Groups 1 and 2 than in controls. Conversely, placental retention longer than 24 h was observed in hormone-treated heifers, and none occurred in the control group. The RU 486 reduced circulating progesterone concentrations in treated heifers, whereas progesterone concentration remained increased in control (P < .01). The results show that RU 486 alone or combined with relaxin induces delivery in late-pregnant heifers. Hormone treatment promotes calving ease with a markedly reduced incidence of the detrimental effects of dystocia, which may be a serious problem in first-calf heifers.

Animals↗
PubMed1995

Acute shifts in relaxin, progesterone, prolactin, and growth hormone secretion in Chinese Meishan gilts during late pregnancy and after hysterectomy.

Pregnant and hysterectomized Chinese Meishan gilts were used to investigate mechanisms regulating the production and secretion of relaxin, progesterone, prolactin (PRL), and growth hormone (GH) during different reproductive states. Gilts were bred to Meishan boars on the 1st d of the second observed estrus, and unmated gilts were hysterectomized on d 8 (estrus = d 0). Blood samples (10 mL) were collected twice daily (0800 and 2000) from d 9 to 120 and every 20 min within a 3-h period on d 112 to 116. Relaxin plasma concentrations were consistently greater in hysterectomized than in pregnant (6 vs 2 ng/mL, P < .05) gilts on d 99 to 109. The surge relaxin release on d 114 was greater in pregnant (66 ng/mL) than in hysterectomized gilts (34 ng/mL, P < .05). Thereafter, relaxin remained consistently increased (12 ng/mL) in hysterectomized gilts, whereas it was basal (< .5 ng/mL) during lactation. Progesterone concentrations decreased by half from d 109 to 115 and remained at 16 ng/mL through d 120 in hysterectomized pigs, whereas in pregnant pigs progesterone became basal after parturition. Prolactin in hysterectomized gilts remained at 4 ng/mL throughout the study period, whereas in pregnant gilts PRL increased steadily from 16 ng/mL on d 99 to 39 ng/mL at parturition and remained increased during lactation. Growth hormone concentrations were similar in hysterectomized and pregnant gilts from d 99 to 114; however, GH concentrations were consistently greater (P < .05) in lactating than in hysterectomized gilts (2.6 vs 1.0 ng/mL, respectively). These results indicate that PRL and GH secretions differ in pregnant and hysterectomized pigs because of the physiological changes necessitated by the onset of lactation.

Animals↗
PubMed1995

Coccidioidomycosis: the other great imitator.

A "great imitator," like the perhaps more familiar syphilis and tuberculosis, coccidioidomycosis has a wide variety of clinical presentations. A recent dramatic surge in the incidence of this saprobe increases the likelihood that clinicians will encounter an infected patient. Although rare, the disseminated form of the disease is potentially fatal. Vigilance and familiarity with the many faces of this pathogen will permit early detection and treatment. We present two cases of disseminated coccidioidomycosis and briefly review this increasingly common fungal infection.

Adult↗
PubMed1995

High-dose-rate intraoperative radiation therapy for colorectal cancer.

Last month, the authors presented the principles of high-dose-rate intraoperative radiation therapy (HDR-IORT), a new approach to intraoperative radiation delivery, as well as their criteria for patient selection, the goals of surgery, and their approach to minimizing surgical morbidity. This month, the authors present the technical aspects of delivering HDR intraoperative brachytherapy, their dosimetry atlas, and their results using HDR-IORT in the treatment of patients with colorectal cancer.

Adenocarcinoma↗
PubMed1995

High-dose-rate intraoperative radiation therapy for colorectal cancer.

Intraoperative radiation therapy (IORT) has the obvious advantage of maximally irradiating the tumor bed while eliminating surrounding normal organs from the field of radiation. This approach has been especially useful when the required radiation dose exceeds the tolerance dose of the surrounding normal tissues. However, the application of IORT has been significantly limited by cost, logistic issues, and technical problems related to delivering treatment to difficult anatomic areas. We have developed a new approach to IORT that obviates the need for patient transport: In a dedicated, shielded operating room, the surgery is performed and IORT is delivered via HDR remote afterloading. We have found this approach to be cost effective, logistically sound, and suitable for a wide range of anatomic sites. The technical aspects of the procedure, as well our preliminary results in colorectal cancer, will be presented.

Colorectal Neoplasms↗
PubMed1994

Treatment of liver metastases from colorectal cancer with radioactive implants.

BACKGROUND: Long-term survival and possible cure can be achieved in selected patients after resection of liver metastases from a colorectal primary tumor. In this study, the authors used radioactive implants as adjunctive therapy for patients who had incomplete resections of liver metastases. METHODS: From 1979 to 1990, 17 implants were performed in 12 patients (median age, 61 years). Brachytherapy was performed for microscopically positive margins in 7 implants and for gross residual disease in 10 implants. Volume implants were performed for gross residual disease using 125I seeds, with a median matched peripheral dose of 160 Gy. Most of the implants for microscopic residual disease were planar implants with 125I suture seeds, with a median treatment dose of 150 Gy. RESULTS: There were no serious postoperative complications. Overall median survival was 18 months, and 42% of patients survived 2 years or more. Extrahepatic metastases occurred in 83% of patients (10 of 12). Intrahepatic failure close to the implanted site occurred in 42% of patients (5 of 12), and intrahepatic failure anatomically remote from the implant site occurred in 25% (3 of 12). CONCLUSIONS: This approach is feasible and achieves reasonable local control of residual disease after resection of hepatic metastases from colorectal cancer. The anatomic pattern of failure supports efforts to intensify local therapy and to address the high rate of distant metastases.

Adult↗
PubMed1994

Diode dosimetry of 103Pd model 200 seed in water phantom.

The relative dose distribution around the 103Pd model 200 implant seed was measured with a computerized data acquisition system employing a p-n junction silicon diode immersed in a water phantom. Data are acquired in polar coordinates by computer control of (1) the diode distance from the seed center and (2) the rotation angle of seed about a transverse axis. Transverse axis data are compared with thermoluminescent dosimeter (TLD) measurements and a Monte Carlo calculation by others.

Brachytherapy↗
PubMed1994

Intracerebroventricular injection of corticotropin-releasing hormone in the pig: acute effects on behavior, adrenocorticotropin secretion, and immune suppression.

Corticotropin-releasing hormone (CRH) has been implicated as an important mediator of behavior, immune, and neuroendocrine systems in animals experiencing stress, but its effects on these systems have not been evaluated in an integrated whole animal model. In this experiment we injected porcine and rat CRH (pCRH and rCRH) intracerebroventricularly (icv) and simultaneously and chronologically monitored acute changes in behavior, endocrine, and immune function in the pig. PBS or CRH (15, 50, and 150 micrograms pCRH and 15 and 150 micrograms rCRH) was injected icv, and serial blood samples were collected via an indwelling jugular catheter so that behavior could be monitored simultaneously. The central administration of pCRH and rCRH induced immediate dose-dependent behavioral and physiological responses. Pigs receiving 15 micrograms of either pCRH or rCRH had increased plasma ACTH and were hyperactive and vocal. However, when higher doses (i.e. 50 or 150 micrograms) were administered icv, the endocrine and behavioral responses were accompanied by a profound suppression of Concanavalin-A-induced lymphocyte proliferation. For example, pigs receiving 150 micrograms pCRH had increased plasma ACTH and motor activity at 10 min (P < 0.01) and suppressed lymphocyte proliferation at 30 min (P < 0.001). Whereas ACTH secretion declined after 40 min, the lymphocyte suppression and increased motor activity were sustained, suggesting different control mechanisms. It is suggested that although ACTH and cortisol may have negative feedback effects on ACTH secretion, they did not have these effects on the behavioral action of CRH. Furthermore, although the lowest dose of CRH (15 micrograms) induced motor activity and ACTH secretion, higher doses (50 or 150 micrograms) were necessary for suppression of mitogen-induced lymphocyte proliferation. These findings demonstrate that CRH in the pig brain is active for inducing simultaneous changes in behavioral and physiological systems and are, therefore, consistent with the hypothesis that brain CRH is important in mediating the interaction among behavior, endocrine, and immune systems in animals experiencing stress.

Adrenocorticotropic Hormone↗