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Biomedical subjects

L M Freeman

Publications and source records attributed to L M Freeman.

At least 37 records · Page 2Linked to original sources

Adjuvant arthritis as a model of inflammatory cachexia.

OBJECTIVE: To determine whether adjuvant arthritis (AA) leads to changes in body composition and cytokine production similar to those seen in patients with rheumatoid arthritis. METHODS: AA was induced in Lewis rats using Freund's complete adjuvant. Body cell mass was measured by determining the concentration of total exchangeable potassium using 42K gavage. Splenocyte production of interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) was measured by bioassay. Weight and food intake were also measured. RESULTS: Animals that developed AA lost 6% of their body weight by the onset of clinically evident arthritis (day 14; P < 0.01) and lost 20% by the end of the inflammatory phase of AA (day 28; P < 0.0001). Body cell mass fell 24.7 +/- 8.6% (mean +/- SEM) in animals with AA, but did not change significantly in controls (increase of 6.3 +/- 7.9%) (P < 0.03). Pair-fed animals lost one-fourth of the weight lost by the animals with AA (P < 0.01), indicating that anorexia alone does not explain inflammatory cachexia. Weight loss was correlated with TNF alpha production by spleen mononuclear cells (r = 0.68, P < 0.007), and a weaker correlation was seen with IL-1 production (r = 0.45, P < 0.04). CONCLUSION: AA in rats is a useful model of inflammatory cachexia that mimics the human pathophysiology in important ways, and is consistent with cytokine-driven cachexia in chronic inflammatory arthritis.

Animals↗

Magnesium status and the effect of magnesium supplementation in feline hypertrophic cardiomyopathy.

Magnesium deficiency has been associated with the development of cardiovascular disease in several species. Cats may be predisposed to alterations in magnesium status because of recent changes in the composition of commercial feline diets. The purposes of this study were 1) to examine the dietary history of cats with hypertrophic cardiomyopathy (HCM), 2) to study magnesium status of cats with HCM compared to normal cats, and 3) to determine the effects of magnesium supplementation in cats with HCM. In part 1 of the study, diets of 65 cats with HCM were examined retrospectively. Forty of the 45 cats for which diets could be determined (89%) ate a diet designed to be magnesium-restricted and/or to produce an acidic urine. In part 2 of the study, 10 cats with HCM were compared to 10 healthy control cats for serum creatinine and magnesium; urine creatinine and magnesium, urine specific gravity and pH, and fractional excretion of magnesium. Urine creatinine and specific gravity were higher in control cats than in cats with HCM. No other differences were found between the 2 groups. In part 3, cats with HCM were supplemented with either 210 mg magnesium chloride (n = 15) or 210 mg lactose (n = 15) for 12 wk. No differences between the 2 groups were found for changes in either magnesium status or echocardiographic parameters. However, the 30 cats with HCM, as a group, did show significant improvements in measures of cardiac hypertrophy over the 12-week period. This was likely the result of treatment with other medications, rather than the magnesium supplementation. The results of this study suggest that cats with HCM are likely to be fed magnesium-restricted diets, but that they do not appear to have altered magnesium status compared to healthy controls.

Animals↗

Idiopathic dilated cardiomyopathy in Dalmatians: nine cases (1990-1995).

OBJECTIVE: To describe the historical, clinical, and echocardiographic findings in Dalmatians with dilated cardiomyopathy (DCM). DESIGN: Retrospective case series. SAMPLE POPULATION: 9 Dalmatians with a diagnosis of DCM and congestive heart failure (CHF), 9 Doberman Pinschers with DCM and CHF, and 9 dogs of other breeds with DCM and CHF. PROCEDURE: Disease history; signalment; physical, radiographic, and echocardiographic examination findings; treatment; and outcome from medical records were analyzed. RESULTS: All Dalmatians were male, with a mean age of 6.8 years. Eight dogs had been fed a commercially available low-protein diet formulated for the prevention of urate uroliths. All dogs had clinical signs consistent with left-sided CHF and had marked left ventricular systolic dysfunction and severe left ventricular dilatation, although arrhythmias were not an important finding in this series of dogs. Median duration of survival was 10 months. CLINICAL IMPLICATIONS: The DCM syndrome in Dalmatians has some qualities that are distinct from DCM in other breeds of dogs.

Animals↗

Androgen spares androgen-insensitive motoneurons from apoptosis in the spinal nucleus of the bulbocavernosus in rats.

The spinal nucleus of the bulbocavernosus (SNB) is a sexually dimorphic motor nucleus in the rat lumbar spinal cord. The sex difference arises through the androgenic sparing of the motoneurons and their target muscles from ontogenetic cell death. Indirect evidence suggests that androgen acts on the target muscles rather than directly on SNB motoneurons to spare them from death. The testicular feminization mutation (Tfm), a defect in the androgen receptor (AR), blocks androgenic sparing of SNB motoneurons and their targets. The pattern of AR immunocytochemistry was previously found to be different in adult Tfm and wild-type rats: immunostaining was nuclear in most SNB cells of wild-type rats, but very few SNB cells display nuclear AR immunostaining in affected Tfm rats. Because the Tfm mutation is carried on the X chromosome, random X inactivation during development makes female carriers of Tfm (+/Tfm) genetic mosaics for androgen sensitivity. Tfm carriers, their wild-type sisters, and affected Tfm males were treated with perinatal testosterone and immunocytochemistry was used to detect androgen receptor in the SNB when the rats reached adulthood. Mosaic females could be distinguished from their wild-type sisters by external morphology. In such perinatally androgenized mosaics, adult SNB cells were equally divided between wild-type and Tfm genotype, as indicated by AR immunocytochemistry. In contrast, the pattern of AR immunocytochemistry in target muscles of mosaics appeared similar to that of wild-type females. These results indicate that early androgen spared both androgen-sensitive and -insensitive motoneurons from cell death, confirming a site of androgen action other than the motoneurons themselves.

Androgens↗

Nuclear medicine in Vietnam.

Despite the presence of many bright Vietnamese nuclear medicine physicians and scientists, the level of clinical practice languishes seriously behind that of Europe, the United States, Japan and most other parts of the world. This is directly attributable to the country's severe poverty, which places serious constraints on the number of available pieces of functioning imaging equipment, the ability to service equipment and establish appropriate quality assurance and preventative maintenance programs and the ability to purchase adequate radiopharmaceuticals to serve their patients' needs. At this time, the Vietnamese nuclear medicine community is anxious to enhance its contact with colleagues throughout the world. They need and welcome help in obtaining instrumentation, in vivo and in vitro diagnostic kits and educational aids from outside agencies, commercial countries and medical centers that are able to assist them. They would be most appreciative to receive and encourage visits from professional colleagues who would be able to provide lectures, seminars, books, journals and other teaching tools that would contribute to the upgrading of their clinical practice of nuclear medicine.

Humans↗

Preoperative parathyroid localization with sestamibi.

PURPOSE: Results of noninvasive preoperative parathyroid localization with technetium99m-labeled sestamibi are reported in a series of 51 patients. PATIENTS AND METHODS: Forty-four patients had hyperparathyroidism surgically treated for the first time and seven patients underwent reexploration for recurrent or persistent hyperparathyroidism. Preoperative scintigraphy with sestamibi was performed in all patients before surgical exploration. Results of the radionuclide studies were compared with surgical and pathologic findings. RESULTS: Twenty-six patients had solitary adenomas. All 26 were localized preoperatively by the scans. Among 18 patients with multiglandular pathology, 69 pathological glands were found at surgery. Thirty-six of these glands, in 15 patients, were localized by the scans. Among the 7 patients evaluated after failed exploration or recurrent hyperparathyroidism, 7 pathologic glands were found, of which 6 were correctly localized by the scan. Ectopic lesions in 2 patients were correctly localized by the scan. CONCLUSIONS: The authors conclude that sestamibi parathyroid localization is an effective method for preoperative parathyroid localization, with accuracy exceeding that of other noninvasive studies.

Adenoma↗

Appearance of a hepatic hemangioma on prostate immunoscintigraphy. Value of early images.

In this case, the authors describe the appearance of hemangioma, the most common benign tumor of the liver, on early and delayed in-111 CP antibody images. The early immunoscintigraphic images show intense blood pool activity comparable in appearance to labeled RBC imaging, the current procedure of choice for confirming the diagnosis of hemangioma. In combination with disappearance of blood pool activity on the late scintigraphic images, these findings are pathognomonic for hemangioma and sufficiently distinct from the appearance of hepatic metastases on in-111 labeled antibody images to obviate the need for further confirmatory diagnostic studies.

Antibodies, Monoclonal↗

Motoneurons innervating guinea pig perineal muscles are sexually dimorphic in size but not number.

Sexual differentiation occurs prenatally in guinea pigs but extends into the postnatal period in rats. Steroids affect the development of two motoneuron nuclei of the rat lumbar spinal cord that innervate sexually dimorphic perineal muscles. The spinal nucleus of the bulbocavernosus (SNB) innervates the bulbocavernosus (BC) and levator ani (LA) muscles while the dorsolateral nucleus (DLN) innervates the ischiocavernosus (IC). In male rats, perinatal testosterone prevents degeneration of these muscles and results in a sex difference in both motoneuron size and number in adulthood. For comparative purposes, we examined the guinea pig motoneurons innervating these muscles, as well as those innervating the retractor penis (RP) and retractor clitoris (RC), muscles that have no counterpart in rats. Injections of horseradish peroxidase localized the BC/LA and IC motoneurons of guinea pigs to discrete columns in spinal levels L6 and S1, with the BC/LA motoneurons occupying a more medial position. The RP/RC motoneurons were found in L5. Motoneuronal soma area was larger in males in all examined motor pools, as was nuclear area of BC/LA and IC motoneurons. Although raw counts suggested a sex difference in cell number in the motor columns containing BC/LA and IC motoneurons, either of two different correction procedures for split nuclei error eliminated the sex difference in cell number, emphasizing the importance of such corrections when comparing neurons of different size.

Analysis of Variance↗