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Biomedical subjects

S K Berman

Publications and source records attributed to S K Berman.

13 recordsLinked to original sources
PubMed1997

Nonclinical model for assessing gastric effects of bisphosphonates.

Gastrointestinal intolerance has been associated with amino bisphosphonate therapy in the clinic. The objective of this study was to develop a model for assessing bisphosphonate-induced gastric damage that may aid in the development of future bisphosphonate therapies. Rats were dosed concomitantly with indomethacin (40 mg/kg, subcutaneously) and an amino or pyridinyl bisphosphonate (orally at. 150, 225 or 300 mg/kg). The bisphosphonates studied were pamidronate and alendronate (primary amino bisphosphonates) and risedronate and NE-97221 (pyridinyl bisphosphonates). Macroscopically, alendronate induced significantly (P < 0.05) more antral damage (both lesion length and number) than pamidronate and risedronate at 225 and 300 mg/kg, and more than NE-97221 at 300 mg/kg. NE-97221 induced significantly more antral damage (lesion length) than risedronate at 225 mg/kg and a greater number of lesions compared to pamidronate and risedronate at 225 and 300 mg/kg. The model was validated histologically, and macroscopic findings correlated with histologic evidence of antral mucosal necrosis and inflammatory infiltration of the lamina propria. The calcium chelators EGTA and EDTA did not induce gastric damage in this model when dosed according to the same protocol as the nitrogen-containing bisphosphonates. This suggests that calcium chelation does not account for the gastric effects in this model. The fasted, indomethacin-treated rat provides a novel nonclinical model to assess gastric effects of bisphosphonates, which may aid in the development of future bisphosphonate therapies. These data suggest that when expressed on an actual or anticipated clinical dose basis for osteoporosis (pamidronate, 150 mg; alendronate, 5-10 mg; risedronate and NE-97221, 5 mg), primary amino bisphosphonates may have a greater potential for inducing gastric damage than do pyridinyl bisphosphonates.

Alendronate↗
PubMed1987

Microanatomy of the premamillary artery.

The premamillary artery was studied in 50 unfixed human brain hemispheres (51 vessels were found) which were injected with polyester resin and dissected under the operating microscope. In one hemisphere there was duplication of the premamillary artery. There were premamillary arteries arising from the posterior communicating artery (PCoA) in 49 cases and from the posterior cerebral artery in the remaining two. The arteries originated from the superior and lateral surfaces of the PCoA and coursed superiorly, laterally, and posteriorly to enter a triangular perforated space limited by the mamillary body and tuber cinereum medially, the optic tract anterolaterally, and the cerebral peduncle posterolaterally. This space is called the paramedian perforated substance. The premamillary artery had an outer diameter of 0.6 +/- 0.2 mm on the right side and 0.6 +/- 0.1 mm on the left. The length of the premamillary artery was 12.0 +/- 2.0 mm on the right side and 12.7 +/- 1.9 mm on the left. Sixty-three percent of the premamillary arteries gave off branches that supplied the cerebral peduncles, optic tract, and paramedian perforated space. The clinical importance of these anatomical data in the symptomatology and management of vascular and neoplastic diseases in and around the posterior circle of Willis is discussed.

Cerebral Arteries↗
PubMed1987

Geriatric neurosurgery.

The "elderly," aged 65 and over, represent a rapidly growing proportion of the American population. Their percentage among the neurosurgical admissions at Henry Ford Hospital increased from 14.4% in 1978 to 22.4% in 1984. Occlusive cerebrovascular disease was the most frequent pathology seen, representing 40% of the population studied. Spinal degenerative myeloradiculopathy represented 14%, tumors 7%, trauma 5.4%, and intracranial hematomas represented 4% of the population. Vascular anomalies represented 3.3% of the patient group, with almost the same number of patients presenting with intracranial hemorrhage. The percentage of patients who were surgically treated was 58%. Mortality was 6.5%, with only 2.5% of the patients requiring special-care-facility placement following release from the hospital. An older group, aged 85 and over, represented 4% of our geriatric population. In the age 85+ group, occlusive cerebrovascular disease was the leading pathology (18% of the population), followed by subdural hematomas (15%), spinal degenerative myeloradiculopathy (11.6%), trigeminal neuralgias (7%), hydrocephalus (4%), vascular anomalies (4%), and tumors (4%). Patients in the age 85+ group were surgically treated in 41% of the cases, with a mortality of less than 10%. In the past, older age (greater than 65 years) was believed to be a contraindication to surgery, however, the increased life expectancy, number, and health of this population made reconsideration of this arbitrary age limit essential. We feel that age alone is not a barrier to proper neurosurgical treatment when other risk factors are adequately managed.

Age Factors↗
PubMed1987

Microanatomy of the posterior communicating artery.

Fifty unfixed cerebral hemispheres were injected with polyester resin and dissected under the operating microscope to show the anatomy of the posterior communicating artery (PCoA). There was a single PCoA in every hemisphere. Eleven (22%) were of fetal origin, and 17 (34%) were hypoplastic. Infundibular dilatations were found in 5 (10%) of the arteries. The outer diameter (OD) of the PCoA at its origin was 1.5 +/- 0.8 mm on the right and 1.6 +/- 0.6 mm on the left. At the junction of the PCoA with the P1 segment of the posterior cerebral artery, the PCoA had an OD of 1.4 +/- 0.7 mm on the right side and 1.6 +/- 0.6 mm on the left. The total length of the PCoA was 12.7 +/- 3.2 mm on the right and 12.5 +/- 1.7 mm on the left side. PCoA branches originated from the superior (36%) or lateral (64%) surface of the PCoA and coursed superiorly, posteriorly, or laterally. These vessels supplied the paramedian perforated substance (21%), the tuber cinereum (16.8%), the sulcus between the optic tract and the tuber cinereum (14.4%), the circuminfundibular anastomosis (11.5%), the mamillary bodies (8.4%), the sulcus between the optic tract and the cerebral peduncles (7.6%), and the cerebral peduncles (5.7%). The largest and most constant branch of the PCoA was the premamillary artery. The number and size of the branches from the PCoA were independent of the size of the parent artery.

Adult↗
PubMed1986

Microanatomy of the anterior cerebral artery.

The microanatomic features of the anterior cerebral artery were studied in 30 unfixed human brains which were injected with tinted polyester resin via cannulation of the internal carotid arteries under microscopic dissection. The outer diameter, length, and number of perforating branches were measured for each of the following vessels: anterior cerebral artery (proximal A1 segment, distal A2 segment), anterior communicating artery, and recurrent artery of Heubner. The perforating branches of the proximal segment of the anterior cerebral artery penetrated the brain at the anterior perforated substance, lateral chiasm, and optic tracts. The perforating branches of the anterior communicating artery penetrated the brain at the lamina terminalis, anterior perforated substance, and medial chiasm. The first 5 mm of the distal anterior cerebral artery (A2) had perforating branches penetrating the brain at the gyrus rectus and olfactory sulcus. The recurrent artery of Heubner originated from the A2 segment of the anterior cerebral artery in 57% of the cases, from the anterior cerebral artery-anterior communicating artery junction in 35%, and from the A1 segment in 8%. The depth of the interhemispheric fissure at the genu was 36.0 +/- 0.5 mm and at the midbody of the corpus callosum, 35.0 +/- 0.5 mm. Extension of the dissection to approach the anterior communicating artery from the genu of the corpus callosum using the anterior interhemispheric route was an additional 31.7 +/- 0.7 mm. The callosal arterial supply from the anterior cerebral artery showed short callosal branches in all brain specimens and long callosal vessels in 10% of the specimens.

Cerebral Arteries↗
PubMed1986

Anterior cerebral artery reconstruction.

Anterior cerebral artery end-to-end, end-to-side, and side-to-side anastomoses and grafting procedures including bypass and interposition using segments of the posterior cerebral artery harvested from the same specimen were performed. The reconstruction procedures were accomplished experimentally with the A1 and A2 segments of the anterior cerebral artery, the recurrent artery of Heubner (RAH), and the orbitofrontal and frontopolar arteries in end-to-end or end-to-side anastomosis to the A1 segment. Side-to-side anastomoses between both A2 or A3 segments were completed without difficulty. We utilized the anatomical and experimental reconstruction data in the performance of three surgical procedures for aneurysms in this area. An A1 to A2 end-to-end anastomosis, an A2 to A2 end-to-side anastomosis, and an end-to-end anastomosis of the RAh were performed with no technical difficulties or complications. This study shows the feasibility of these microvascular reconstruction procedures in the anterobasal part of the interhemisphere, where cerebral aneurysms frequently develop.

Adult↗
PubMed1986

Microvascular anatomy of the interpeduncular fossa.

An understanding of the microvascular anatomy of the midbrain and posterior diencephalon is essential in the surgical management of lesions in that region. A description of the arterial pattern of blood supply to these areas is the purpose of this study. Perforating branches originating from the last 5 mm of the basilar artery, from the initial 7 mm of both superior cerebellar arteries (SCA's), and from the initial segment (P1 segment) of the posterior cerebral artery were studied in 56 unfixed human cadaver brain hemispheres. The brains were injected with polyester resin. The perforating branches penetrated through a small space in the upper part of the interpeduncular fossa. The anterior two-thirds of this space was occupied by the posterior perforated substance (PPS), and the posterior one-third was the site of penetration of the branches that supply the inferior mesencephalon. The PPS was divided into anterior and posterior halves. The anterior half was perforated by the paramedian thalamic arteries (diameter 0.57 +/- 0.11 mm) while the superior paramedian mesencephalic arteries (diameter 0.20 +/- 0.06 mm) perforated the posterior half. The perforating arteries originated from a trunk exclusive to the anterior half in 30%, from a trunk supplying both halves in 57%, and from a trunk exclusive to the posterior half in 13% of specimens. There were 26 naturally occurring anastomoses between the perforating branches. The paramedian inferior mesencephalic arteries penetrating the posterior one-third of the upper part of the interpeduncular fossa arose from the P1 segment in 32% of the brains studied, from the proximal 7 mm of the SCA in 45%, and from the last 5 mm of the basilar artery in 23%.

Basilar Artery↗
PubMed1986

Surgical anatomy of the arteries of the posterior fossa.

The development of revascularization for vertebrobasilar ischemic events has created a need to identify the best sites at which to perform bypass procedures. Since the occlusive process may selectively affect various levels of the vertebrobasilar tree, sites in different vessels must be used to reestablish flow distal to the area of occlusion. Twenty-seven unfixed human brains were obtained 4 to 8 hours post mortem, and the vertebrobasilar system was injected with polyester resin. Under a surgical microscope the outer diameter, length, and site of origin of major branches were recorded for the following arteries: vertebral, basilar, posterior inferior cerebellar (PICA), anterior inferior cerebellar (AICA), superior cerebellar (SCA), and posterior cerebral (PCA). The ideal sites for an anastomosis were identified as the pretonsillar segment of the PICA, the second portion of the AICA, the perimesencephalic segment of the SCA, and the perimesencephalic part of the PCA. Based on the anatomical observations reported here, these were the best sites because of their outer diameter, degree of mobility, least number of branches, and frequency of occurrence. Use of two of these arteries, however, may pose potential problems: although the PCA has an ideal outer diameter, it also has numerous branches to the brain stem in its most accessible site in the perimesencephalic area; and the PICA is not consistently present, being found in only 75% of the 27 specimens studied.

Basilar Artery↗
PubMed1985

Aneurysm clip motion during magnetic resonance imaging: in vivo experimental study with metallurgical factor analysis.

Because of various mechanical, metallurgical, and commercial constraints, aneurysm clips are manufactured from different alloys, including several stainless steel and cobalt alloys. Some of the steels contain volume fractions of the crystal phase known as martensite. Martensitic alloys have body-centered cubic structure, are prone to stress corrosion failure, and are ferromagnetic. Martensitic steel can be displaced like a compass needle when exposed to a magnetic field such as that generated during magnetic resonance imaging (MRI). The force exerted by the magnetic field is proportional to the volume fraction of the magnetic phase. We investigated the martensitic content and magnetic field-induced displacement of 12 common aneurysm clips. Four clips of each of the following types were examined: Sugita, Sundt-Kees Multi-Angle, Heifetz (two types), Vari-Angle McFadden, Yasargil (two types), Scoville, Mayfield, Vari-Angle, Pivot, and Kapp. Phase homogeneity and crystal structure were analyzed by x-ray diffraction using a Phillips x-ray diffractometer. Clip deflection in an Oxford Research Systems MRI spectrometer was measured in our in vivo rat abdominal aortic aneurysm model. Results showed that the volume fraction of the martensitic phase in the various clips correlated with the magnitude of the deflection. Among the clips examined, the Yasargil, Sugita, Heifetz Elgiloy, and Vari-Angle McFadden had a nonmartensitic composition and did not deflect in the magnetic field. The Scoville contained 5% martensite and deflected only marginally. Martensite comprised 35% of the Mayfield clip, which deflected 45 degrees, and 90% of the Heifetz, Vari-Angle, Pivot, and Sundt-Kees Multi-Angle clips, which deflected approximately 70 degrees or slipped off the aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)

Alloys↗
PubMed1985

Acute inflammation and endothelial injury in vein grafts.

An experimental study of autogenous vein graft morphology 6 hours after arterial implantation was performed in dogs. The animals were divided into five groups. The first control group had veins harvested and stored but not implanted. The endothelium showed excellent preservation by routine histology and scanning electron microscopy. The second control group had grafts implanted and flow decreased to 30 to 50 ml/minute. There was a massive acute inflammatory response with subendothelial and transmural accumulation of neutrophils causing widespread endothelial sloughing. A third group had grafts implanted, but flow was not reduced (mean, 170 ml/minute). Although an inflammatory response was also present, it was much less severe than in the low flow grafts and the endothelium remained grossly intact. Two other groups had low flow grafts implanted, but were treated with either lidocaine or steroids. Lidocaine had no effect on the inflammatory response or endothelial injury. High doses of alpha-methylprednisolone succinate almost completely prevented both endothelial loss and inflammatory infiltration. This study supports the premise that an acute inflammatory response can initiate endothelial injury after autogenous grafting, an effect that is much more prominent in low flow than high flow grafts. It also demonstrated that steroids can almost totally suppress the injury during the initial 6 hours after implantation.

Animals↗
PubMed1985

The perforating branches of the middle cerebral artery. A microanatomical study.

The perforating branches (PFB's) of the middle cerebral artery (MCA) were studied in 34 unfixed brain hemispheres which were injected with a polyester resin and dissected under the operating microscope. Five hundred and eight vessels were identified and their site of origin, branching pattern, outer diameter (OD), and length recorded. Four hundred and two PFB's (79%) originated from the main trunk of the MCA before its division; the remaining 106 vessels (21%) had their origin from branches of the MCA as follows: superior trunk, 43 vessels (8.5%); inferior trunk, 30 vessels (6%); middle trunk, four vessels (0.8%); early temporal branch, 27 vessels (5.3%); and early frontal branch, two vessels (0.4%). The number of PFB's in each hemisphere varied from five to 29 (mean 14.9 +/- 0.7 vessels). The great majority of PFB's (96%) originated along the proximal 17 mm of the MCA. The PFB's arising in the first 10 mm had a mean OD of 0.35 +/- 0.01 mm and a mean length of 9.25 +/- 0.19 mm, and those arising from the second 10 mm had a mean OD of 0.47 +/- 0.02 mm and a mean length of 16.67 +/- 1.4 mm. A clear distinction between a medial and lateral group of PFB's was present in only 14 hemispheres (41%). In nine hemispheres (26%), perforating vessels from the anterior cerebral artery (A1 segment) and from the recurrent artery of Heubner replaced the medial group of PFB's of the MCA. In one case this group originated in an accessory MCA. In three hemispheres (9%) a small anastomosis (OD 0.2 mm) was seen between a PFB of the recurrent artery of Heubner and one of the MCA. From a total of 508 PFB's, 255 vessels (50%) originated as single vessels, while 253 vessels (50%) originated as branches of common stems. The OD of the single vessels ranged from 0.1 mm to 1.1 mm (mean 0.39 +/- 0.02 mm), and the length from 3 to 20 mm (mean 10.8 +/- 0.2 mm). The common stems ranged in OD from 0.6 to 1.8 mm (mean 0.87 +/- 0.04 mm), and in length from 1 to 15 mm (mean 4.1 +/- 0.4 mm). The clinical application of these anatomical data to the management of aneurysms and arteriovenous malformations of the MCA, and in the field of interventional neuroradiology is described. The most frequent pathological entities involving the perforating vessels are also discussed.

Adult↗
PubMed1979

Increases in mitochondrial steroidogenesis after short term incubation of porcine ovarian follicles with luteinizing hormone.

[4-14C]Cholesterol side chain cleavage, progesterone synthesis, and cytochrome oxidase activities were measured in mitochondria from unincubated and short term incubated large (8-10 mm) follicles isolated from porcine ovaries. Compared to the activity of mitochondria from unincubated follicles, specific [4-14C]cholesterol side chain cleavage activity in mitochondria from follicles incubated with LH (0.05 microgrogram/ml) did not change significantly after 12 h, but increased almost 2-fold after 18 h and 5-fold after 24 h. Also, specific mitochondrial progesterone synthesis activity increased dramatically after incubation of follicles for 24 h with LH. In comparison, mitochondria prepared from follicles incubated without LH showed no significant change in specific [4-14C]cholesterol side chain cleavage or progesterone synthesis activities after 18 h of incubation. While both of these activities increased after incubating follicles 24 h without LH, the values were significantly lower than those observed for preparations from follicles incubated with LH. In contrast to these changes in mitochondrial steroidogenesis, specific cytochrome oxidase activity in mitochondria did not change after incubation of follicles without or with LH. It is concluded that incubation of follicles with LH stimulates the development of mitochondrial steroidogenesis but initially does not affect some components of the respiratory chain.

Animals↗