Sex-related differences in composition of otosclerotic and unafflicted stapes.

This research was undertaken to determine whether stapedial composition could be used to distinguish the sex of patients afflicted with otosclerosis and the sex of unafflicted controls. Energy dispersive-electron probe microanalyses (EDS/EPMA) of otosclerotic stapes from 10 male and 13 female patients were compared with analyses from four unafflicted men and five women. The composition of control stapes differed at p << 0.05 (discriminant analyses) from otosclerotic specimens. Thirteen elements analyzed are in two statistical categories: Group I: Ca, Cr, Fe, Zn, Mg, P, and S; and Group II: Al, K, Mn, Na, Si, and Ti. Elements of Group I distinguish unafflicted men from unafflicted women at a high level of significance (p << 0.05). The same group distinguished afflicted men from otosclerotic women at a lower level (p < or = 0.05), but only if comparisons are based on the single (rather than mean) maximum value of each trace element in each stapes, and only if both Cr and Zn are included in the group. Group I elements also distinguish control versus afflicted men and control versus afflicted women at p << 0.05. Group II elements do not distinguish any of the cohorts mentioned at p < or = 0.05, although they do more successfully classify control and afflicted women as to sex than they do men. They also more successfully predict the diseased status of afflicted men and women than the normal status of controls. The elements whose concentrations exhibit sex-related convergence in otosclerotic stapes are either fundamental constituents of stapedial hydroxyapatite in general or are specific activators of enzymes implicated in otosclerosis. Thus further investigation of the role of metal-potentiated enzymes in the origin of the disorder is warranted.

Blue toe syndrome from a "coral reef" aorta.

An endoaortic calcified mass, sometimes referred to as a "coral reef" aorta, is an unusual cause of distal leg microembolization. When discovered it is usually in the suprarenal aorta. We present an unusual case of infrarenal coral reef aorta with symptoms of distal atheroembolism. A review of the literature is also presented.

Composition of the otosclerotic stapes: electron microprobe analyses.

For the first time, otosclerotic stapes have been distinguished from unafflicted controls at a high level of significance by using a spectrum of elements measured by energy-dispersive spectrometer-electron probe microanalyses (EDS/EPMA). Discriminant analyses of the maximum concentration of 13 elements measured at several sites within each of 32 stapes differentiated otosclerotic from unafflicted individuals well above the 95% confidence level. Eight of the 9 control (unafflicted) and 21 of the 23 afflicted stapes were correctly classified. In descending order of contribution to the discriminant function, the elements are Zn > Cr > K > Ca > Si > Mn > Na > Al > Mg > P > Fe > S > Ti. Zinc and chromium account for much of the difference, but discriminant analyses excluding them still distinguish the two groups at the 95% confidence level. These results are consistent with previous reports of high levels of alkaline phosphatase, a zinc-containing enzyme, in afflicted stapes. But the broad spectrum of elements capable of distinguishing otosclerotic stapes warrants study of additional zinc-containing and other metal-containing or metal-activated moieties.

Maturation of bone and dentin matrices in rats flown on the Soviet biosatellite Cosmos 1887.

We have studied the chemistry, hydroxyapatite crystal size, and maturational changes in bone and dentin from rats exposed to microgravity for 12 days in a Soviet biosatellite (Cosmos 1887). Bone ash was reduced in vertebrae (L5) but not in the non-weight-bearing calvaria or mandibles. All tissues had a relatively normal percentage composition of Ca, P, and Mg. Nevertheless, flight rat calvaria and vertebral tissues tended to exhibit lower Ca/P and higher Ca/Mg ratios that any of their weight-matched controls groups, and gradient density analysis (calvaria) indicated a strong shift to the fractions lower specific gravity that was commensurate with impaired rates of matrix-mineral maturation. X-ray diffraction data were confirmatory. Bone hydroxyapatite crystal growth in the mandibles of flight rats was preferentially altered in such a way as to reduce their size (C-axis dimension). But in the mandibular diastemal region devoid of muscle attachments, flight rat bone and dentin were normal with respect to the Ca, P, Mg, and Zn concentrations and Ca/P and Ca/Mg ratios of age-matched controls. These observations affirm the concept that while microgravity most adversely affects the maturation of newly formed matrix and mineral moieties in weight-bearing bone, such effects occur throughout the skeleton.

The elusive isolated hypogastric artery aneurysm: novel presentations.

Isolated aneurysms of the internal iliac artery are rare. Their anatomic location makes them true pelvic aneurysms and they may grow to a large size undetected. Their late recognition may be prompted by rupture or symptoms related to compression of neurologic, gastrointestinal, genitourinary, or venous structures. We have encountered three isolated hypogastric artery aneurysms with unique presentations. In one patient with bilateral isolated hypogastric artery aneurysms, one ruptured into the bladder, and at a later time the other caused ureteral obstruction. Another patient had obturator neuropathy as a result of his aneurysm. In the patient with large bilateral aneurysms, one was detected by rectal examination, and the other was found by palpation of the abdomen. The second patient with a smaller aneurysm required examination of the pelvis by CT scanning to establish the diagnosis. Awareness of the existence of these lesions is required to identify such patients who describe symptoms uncommonly associated with abdominal aneurysms. Operative management consisted of exclusion of the aneurysm and partial or complete aneurysmorrhaphy with preservation of iliac arterial flow to maintain extremity perfusion. Recovery was complete in each instance. A review of published cases is presented.

The effects of spaceflight on the mineralization of rat incisor dentin.

The lower incisors of Male Wistar rats flown for 18.5 days on the Soviet Cosmos-1129 Biosatellite were sectioned and chemically analyzed with an electron microprobe in order to determine whether there were specific effects of spaceflight on dentin formation/mineralization. Control tissues were obtained from rats housed under identical conditions in a land-based mock-up of the Biosatellite. The profiles of calcium (Ca), phosphorus (P), and sulfur (S) concentrations in dentin were measured in continuous traverses (1.0 micron intervals) from the pulp to the dentinoenamel junction. The incisor dentin formed during spaceflight had higher than normal (at 1G) concentrations of Ca (+ 10-15%) and P (+ 20-30%), particularly in the temporally youngest tissues within 80 micron of the pulp which had been least affected by secondary mineralization. The S-concentration profiles tended to decrease with tissue age. Fourier analysis (to determine the growth rhythms) revealed abnormal distributional patterns of S in the recently formed dentin from the Flight rats. The sulfur fluctuations in Flight animals alone periodically peaked above the irregular background fluctuations. These observations indicate that spaceflight has measureable effects on dentinogenesis, and they may also bear on the problem of the regulatory role of proteoglycans in mineralization and in the maturation of mineral and matrix moieties in skeletal tissue.

Effect of spaceflight on the non-weight-bearing bones of rat skeleton.

Male Wistar rats prelabeled with tetracycline to mark surfaces of bone and tooth formation-mineralization were placed into orbit for 18.5 days aboard the Soviet COSMOS-1129 Biosatellite. They were injected with tetracycline for a second and third time on the 6th and 27th days, respectively, after recovery of the Biosatellite. Spaceflight did not alter the rate of periosteal bone formation in the non-weight-bearing ribs and regions of the mandibles, which were covered by masticatory muscles. Bone formation-calcification rates were impaired at those sites in the jaw that had no contiguous muscle (molar region). The remodeling activity on the alveolar bone around the buccal roots of the molar teeth was significantly reduced but without creating a negative balance between formative and resorptive activities. Total Ca, P, and hydroxyproline concentrations in the jaws, incisors, and ribs were normal after spaceflight, but gravity density fractionation studies indicated that in the jaws alone, O-G conditions caused a delay in the maturation of bone mineral and matrix. A 29-day postflight recovery period at earth's gravity was sufficient to fully correct these anomalies. Relative to tooth formation, relatively normal circadian and infradian biorhythmic periodicities of Ca and P in dentin and enamel were maintained during spaceflight. We conclude that most of the non-weight-bearing bones of the rat skeleton are at risk to the effects of hypogravity.

Altered metabolic rhythm of rabbit osteoblasts by tetracycline.

To establish whether there are single or multiple pools of osteoblasts in rabbit bone, animals were injected with tetracycline on various schedules for 1-3 days. Metabolic restraints predicted that a multiple pool model would be feasible only if the percent labeled surfaces of trabecular bone (tibia) doubled when animals were injected on days 1 and 2, 1 and 3, or on days 1, 2, and 3. A single population would be indicated if the extent of labeled surfaces failed to double. Herein, 41.9 +2- 8.1% of bone surfaces labeled after a single injection, and only 60-68% of surfaces labeled after injections on the other schedules. The data inferred tht serial pulse tetracycline injections at 24h intervals caused a shift in the activities of a single population of osteoblasts and their progenitor cells.