In this study the kinematics of partial and total ruptures of the medial collateral ligament of the elbow are investigated. After selective transection of the medial collateral ligament of 8 osteoligamentous intact elbow preparations was performed, 3-dimensional measurements of angular displacement, increase in medial joint opening, and translation of the radial head were examined during application of relevant stress. Increase in joint opening was significant only after complete transection of the anterior part of the medial collateral ligament was performed. The joint opening was detected during valgus and internal rotatory stress only. After partial transection of the anterior bundle of the medial collateral ligament was performed, there was an elbow laxity to valgus and internal rotatory force, which became significant after transection of 100% of the anterior bundle of the medial collateral ligament and was maximum between 70 degrees to 90 degrees of flexion. No radial head movement was seen after partial or total transection of the anterior bundle of the medial collateral ligament was performed. In conclusion, this study indicates that valgus or internal rotatory elbow instability should be evaluated at 70 degrees to 90 degrees of flexion. Detection of partial ruptures in the anterior bundle of the medial collateral ligament based on medial joint opening and increased valgus movement is impossible.

Aged↗

PubMedDate not supplied

MRI of postoperative maxillary cysts.

OBJECTIVE: The purpose of this study is to review the MR characteristics of postoperative maxillary cysts (POMC). MATERIALS AND METHODS: The MR findings in 24 patients with 38 surgically confirmed POMC were retrospectively reviewed. RESULTS: Of 32 cysts detected by MRI, 31 cysts (96.9%) were well demarcated. Nineteen cysts (59.4%) were smooth and the others (40.6%) were irregular. Thirty cysts (93.8%) had signal intensities ranging from that of muscle to that of subcutaneous fat on T1-weighted imaging. On T2-weighted imaging 16 homogeneous (50.0% and 5 inhomogeneous (15.6%) cysts showed signal intensities equal to or higher than subcutaneous fat. The peripheral rims of 11 ring-like cysts (34.4%) also showed signal intensities equal to or higher than subcutaneous fat on T2-weighted imaging. Nine patients (37.5%) had multiple cysts. Their characteristic high signal intensities or ring-like patterns on T2-weighted imaging and well-demarcated margins enabled them to be discriminated from other tumors of the maxillary sinus, such as carcinoma. CONCLUSION: MR imaging is useful for diagnosis of POMC.

Female↗

PubMedDate not supplied

Norepinephrine turnover in the cardiovascular tissues and brain stem of the rabbit during development of one-kidney and two-kidney Goldblatt hypertension.

To assess the role of the sympathetic and central noradrenergic neurons in one- and two- kidney Goldblatt hypertension, we examined the concentration and turnover of norepinephrine (NE) in the aorta, mesenteric artery, left ventricle, hypothalamus, midbrain, and pons medulla of hypertensive and control rabbits. Animals were made hypertensive by constriction of the left renal artery after right nephrectomy (1KGH group) or with the right kidney left intact (2KGH group), or were sham-operated on the renal artery (1KGC and 2KGC groups). At 14 days after the constriction, the blood pressure was increased to 136 +/- 3 mm Hg in the 1KGH vs 98 +/- 3 mm Hg in the 1KGC (p less than 0.001), and 136 +/- 2 mm Hg in the 2KGH vs 94 +/- 2 mm Hg in the 2KGC group (p less than 0.001). Turnover time in the aorta, mesenteric artery, and left ventricle in the 1KGH group was decreased to 47%, 45%, and 65% of that in the 1KGC group, respectively. Results suggest that enhanced sympathetic neuron activity in the cardiovascular system, especially in the arteries, contributes to the development of one-kidney Goldblatt hypertension. Norepinephrine turnover in the cardiovascular tissues in the 2KGH group and in the brain stem in the 1KGH and 2KGH group was not different from that in the control group.

Animals↗

PubMedDate not supplied

Effect of high and low sodium intake on norepinephrine turnover in the cardiovascular tissues and brain stem of the rabbit.

To assess the relationship between sympathetic nerve function and sodium intake, we examined norepinephrine (NE) turnover in several cardiovascular tissues and the brain stem of rabbits maintained for 3 weeks on high (86 mEQ), normal (14 mEQ), and low (0.2 mEQ/day) sodium diet. None of the diets changed the blood pressure significantly. Plasma renin activity became high in the low sodium group and low in the high sodium group at the end of the treatment. NE turnover was measured from the rate of decline of tissue NE concentration after administration of alpha-methyl-p-tyrosine. Variation of sodium intake exerted opposite effects on NE turnover in the periphery and in the central nervous system; increasing sodium intake caused an increase in NE turnover in the thoracic aorta, mesenteric vein, and left ventricle, and a decrease in the hypothalamus, midbrain, and pons medulla. But in the mesenteric vein, and left ventricle, and a decrease in the hypothalamus, midbrain, and pons medulla. But in the mesenteric artery and abdominal aorta it was not affected by dietary sodium manipulation. The results show the varying influence of sodium balance on the central and peripheral noradrenergic neuron activity.

Adrenergic Fibers↗

PubMedDate not supplied

Vascular effects of neuropeptides on nasal mucosa.

We used dog nasal blood vessels and an in vitro muscle tension-detecting technique to examine the vascular effects of several neuropeptides: vasoactive intestinal polypeptide, substance P, neurotensin, somatostatin, and neuropeptide Y (NPY). Electrically induced vasoconstriction was inhibited by every peptide except neurotensin, which enhanced this response. Every preparation treated with somatostatin, and one tissue treated with NPY, showed an enhanced noradrenaline-induced contraction. Only NPY caused a tissue contraction. Preparations precontracted by methoxamine were relaxed by every peptide. These results indicate that all peptides examined have marked but varied vasoactivities.

Animals↗