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J M Mathis

Publications and source records attributed to J M Mathis.

At least 19 recordsLinked to original sources
PubMed2005

A human adenoviral vector with a chimeric fiber from canine adenovirus type 1 results in novel expanded tropism for cancer gene therapy.

The development of novel therapeutic strategies is imperative for the treatment of advanced cancers like ovarian cancer and glioma, which are resistant to most traditional treatment modalities. In this regard, adenoviral (Ad) cancer gene therapy is a promising approach. However, the gene delivery efficiency of human serotype 5 recombinant adenoviruses (Ad5) in cancer gene therapy clinical trials to date has been limited, mainly due to the paucity of the primary Ad5 receptor, the coxsackie and adenovirus receptor (CAR), on human cancer cells. To circumvent CAR deficiency, Ad5 vectors have been retargeted by creating chimeric fibers possessing the knob domains of alternate human Ad serotypes. Recently, more radical modifications based on 'xenotype' knob switching with non-human adenovirus have been exploited. Herein, we present the characterization of a novel vector derived from a recombinant Ad5 vector containing the canine adenovirus serotype 1 (CAV-1) knob (Ad5Luc1-CK1), the tropism of which has not been previously described. We compared the function of this vector with our other chimeric viruses displaying the CAV-2 knob (Ad5Luc1-CK2) and Ad3 knob (Ad5/3Luc1). Our data demonstrate that the CAV-1 knob can alter Ad5 tropism through the use of a CAR-independent entry pathway distinct from that of both Ad5Luc1-CK2 and Ad5/3-Luc1. In fact, the gene transfer efficiency of this novel vector in ovarian cancer cell lines, and more importantly in patient ovarian cancer primary tissue slice samples, was superior relative to all other vectors applied in this study. Thus, CAV-1 knob xenotype gene transfer represents a viable means to achieve enhanced transduction of low-CAR tumors.

Adenoviruses, Canine↗
PubMed2003

Profiling transcript levels for steroidogenic enzymes in fetal tissues.

Cytochrome P450 (CYP) and hydroxysteroid dehydrogenase enzymes are involved in the conversion of cholesterol to steroid hormones. These enzymes are primarily expressed in the placenta, adrenal and gonads. Interestingly, some of these enzyme activities have been demonstrated in non-endocrine tissues, where they may be involved in important paracrine and autocrine actions. This is particularly the case in the human fetus where steroid precursors circulate at high levels and could be metabolized within tissues to produce active steroid hormones. Herein, we tested the hypothesis that transcripts for steroidogenic enzymes are expressed in fetal tissues other than the classical steroidogenic organs. To test this hypothesis, real-time reverse transcription polymerase chain reaction (RT-RTPCR) assays were developed that quantify mRNA levels for steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage (CYP11A), 3beta-hydroxysteroid dehydrogenase types 1 and 2 (HSD3B1 and HSD3B2), 17alpha-hydroxylase (CYP17), 21-hydroxylase (CYP21), 11beta-hydroxylase (CYP11B1), aldosterone synthase (CYP11B2) and aromatase (CYP19). The use of RT-RTPCR allows the specific detection of these transcripts at levels that would not be detectable using northern analysis. In addition, this method can detect levels of transcript that would not lead to sufficient protein for detection of enzymatic activity of protein by western analysis. Thus, this methodology can detect low levels of expression that could play a role in regulating intra-tissue concentrations of steroid hormone. Total RNAs used for RT-RTPCR analysis were isolated from several human fetal tissues, including adrenal, testis, ovary, placenta, aorta, brain, liver, kidney, heart, lung, pancreas, prostate, stomach, and thymus. Our findings suggest that RT-RTPCR is a powerful tool for the examination of steroidogenic enzyme mRNA expressions. Using this approach, we have identified and quantified transcript levels of StAR and steroidogenic enzymes in several endocrine and non-endocrine fetal tissues. Even though some of the mRNA levels measured in these peripheral tissues are extremely lower in respect to the steroidogenic tissues, they could be sufficient to produce local (i.e. autocrine and paracrine) effects because produced steroids are not diluted into the entire circulation. These findings open new perspectives on the role of steroid hormones synthesized locally as probable regulatory factors of the development of several organ systems.

3-Hydroxysteroid Dehydrogenases↗
PubMed2002

Material properties of various cements for use with vertebroplasty.

The purpose of the current study was to measure the material properties of various cements prepared per manufacturers' recommendations and of cements modified according to compositions developed by clinicians with experience performing vertebroplasty. Cement was prepared, cast to form cylindrical specimens, and tested in compression. The optical density of specimens from the various cement preparations was measured. Batches of Simplex P and Cranioplastic cement were also prepared with increased concentrations of BaSO4 (20% and 30%; and 10%, 20% and 30%, respectively) to evaluate the effect of additional BaSO4. Compressive modulus values for polymethylmethacrylate cements ranged from 2-2.7 GPa; some differences were significant (p<0.05). Compared with polymethylmethacrylate cements, Orthocomp exhibited almost twice the compressive modulus and 2-3 times the strength values. Increasing the BaSO4 concentration in Simplex P and Cranioplastic significantly (p<0.05) affected their material properties; however, it is unknown if these changes in material properties are clinically important. Optical density increased as a function of concentration of the opacifying agent added. The current study provides clinicians with information on changes in the material properties of bone cements when the compositions are altered in a manner consistent with the practice of vertebroplasty.

Journal Article↗
PubMed2002

Quantitative assessment of CYP11B1 and CYP11B2 expression in aldosterone-producing adenomas.

BACKGROUND: The presence and pathophysiological role of CYP11B1 (11beta-hydroxylase) gene in the zona glomerulosa of human adrenal cortex is still controversial. METHODS: In order to specifically quantify CYP11B1, CYP11B2 (aldosterone synthase) and CYP17(17alpha-hydroxylase) mRNA levels, we developed a real-time RT-PCR assay and examined the expression in a series of adrenal tIssues, including six normal adrenals from patients adrenalectomized for renal cancer and twelve aldosterone-producing adenomas (APA) from patients with primary aldosteronism. RESULTS: CYP11B1 mRNA levels were clearly detected in normal adrenals, which comprised both zona glomerulosa and fasciculata/reticularis cells, but were also measured at a lower range (P<0.05) in APA. The levels of CYP11B2 mRNA were lower (P<0.005) in normal adrenals than in APA. CYP17 mRNAlevels were similar in normal adrenals and in APA. In patients with APA, CYP11B2 and CYP11B1 mRNA levels were not correlated either with basal aldosterone or with the change from basal aldosterone in response to posture or to dexamethasone. No correlation between CYP11B1 mRNA or CYP11B2 mRNA and the percentage of zona fasciculata-like cells was observed in APA. CONCLUSIONS: Real-time RT-PCR can be reliably used to quantify CYP11B1 and CYP11B2 mRNA levels in adrenal tIssues. Expression of CYP11B1 in hyperfunctioning zona glomerulosa suggests an additional formation of corticosterone via 11beta-hydroxylase, providing further substrate for aldosterone biosynthesis. CYP11B1 and CYP11B2 mRNA levels in APA are not related to the in vivo secretory activity of glomerulosa cells, where post-transcriptional factors might ultimately regulate aldosterone production.

Adenoma↗
PubMed2001

The biomechanics of vertebroplasty. The effect of cement volume on mechanical behavior.

STUDY DESIGN: Ex vivo biomechanical study using osteoporotic cadaveric vertebral bodies. OBJECTIVE: To determine the association between the volume of cement injected during percutaneous vertebroplasty and the restoration of strength and stiffness in osteoporotic vertebral bodies, two investigational cements were studied: Orthocomp (Orthovita, Malvern, PA) and Simplex 20 (Simplex P with 20% by weight barium sulfate content; Stryker-Howmedica-Osteonics, Rutherford, NJ). SUMMARY OF BACKGROUND DATA: Previous biomechanical studies have shown that injections of 8-10 mL of cement during vertebroplasty restore or increase vertebral body strength and stiffness; however, the dose-response association between cement volume and restoration of strength and stiffness is unknown. METHODS: Compression fractures were experimentally created in 144 vertebral bodies (T6-L5) obtained from 12 osteoporotic spines harvested from female cadavers. After initial strength and stiffness were determined, the vertebral bodies were stabilized using bipedicular injections of cement totaling 2, 4, 6, or 8 mL and recompressed, after which post-treatment strength and stiffness were measured. Strength and stiffness were considered restored when post-treatment values were not significantly different from initial values. RESULTS: Strength was restored for all regions when 2 mL of either cement was injected. To restore stiffness with Orthocomp, the thoracic and thoracolumbar regions required 4 mL, but the lumbar region required 6 mL. To restore stiffness with Simplex 20, the thoracic and lumbar regions required 4 mL, but the thoracolumbar region required 8 mL. CONCLUSION: These data provide guidance on the cement volumes needed to restore biomechanical integrity to compressed osteoporotic vertebral bodies.

Aged↗
PubMed2001

An ex vivo biomechanical evaluation of a hydroxyapatite cement for use with vertebroplasty.

STUDY DESIGN: Comparative ex vivo biomechanical study. OBJECTIVE: To determine the strength and stiffness of osteoporotic vertebral bodies subjected to compression fractures and stabilized via bipedicular injections of the following: 1) Simplex P (Stryker-Howmedica-Osteonics, Rutherford, NJ), 2) Simplex P formulated consistent with the practice of vertebroplasty (F2), or 3) BoneSource (Stryker-Howmedica-Osteonics). SUMMARY OF BACKGROUND DATA: Little is known about the mechanical stabilization afforded by new materials proposed for use with vertebroplasty. METHODS: Vertebral bodies (T8-T10 and L2-L4) from each of 10 fresh spines were harvested from female cadavers (81 +/- 12 years), screened for bone density (t score, -3.8 +/- 1.1; bone mineral density, 0.75 +/- 15 g/cm2), disarticulated, and compressed to determine initial strength and stiffness. The fractured vertebral bodies were stabilized via bipedicular injections of 4 mL (thoracic) or 6 mL (lumbar) and then recrushed. RESULTS: Vertebral bodies repaired with Simplex P resulted in significantly greater strength (P < 0.05) relative to their prefracture states, those repaired with BoneSource resulted in the restoration of initial strength for both the thoracic and lumbar level, and those repaired with F2 resulted in significantly greater strength (P < 0.05) in the thoracic region and restoration of strength in the lumbar region. All cement treatments resulted in significantly less stiffness compared with initial values. CONCLUSIONS: All three materials tested restored or increased vertebral body strength, but none restored stiffness. Both new materials show promise for use in percutaneous vertebroplasty, but they need clinical evaluation.

Aged↗
PubMed2001

An ex vivo biomechanical evaluation of an inflatable bone tamp used in the treatment of compression fracture.

STUDY DESIGN: Ex vivo biomechanical study using osteoporotic cadaveric vertebral bodies. OBJECTIVES: To determine if the inflatable bone tamp (tamp) restores height to compressed vertebral bodies and to compare the biomechanical properties of isolated, fractured osteoporotic vertebral bodies treated by kyphoplasty (tamp) or vertebroplasty. SUMMARY OF BACKGROUND DATA: Previous biomechanical studies have shown that vertebroplasty increases vertebral body strength and restores vertebral body stiffness, but does not restore vertebral body height lost as a result of compression fracture. METHODS: Compression fractures were experimentally created in 16 osteoporotic VBs assigned to either the tamp or percutaneous vertebroplasty group. The tamp treatment consisted of inserting balloon-like devices into the vertebral body, inflating the bone tamp, and filling the void with Simplex P (Howmedica, Rutherford, NJ) bone cement. The percutaneous vertebroplasty treatment consisted of directly injecting Cranioplastic bone cement (CMW, Blackpool, UK) into the vertebral body. Pre- and posttreatment heights were measured, and the repaired vertebral bodies were recompressed to determine posttreatment strength and stiffness values. RESULTS: The tamp treatment resulted in significant restoration (97%) of vertebral body height lost after compression, whereas percutaneous vertebroplasty treatment resulted in a significantly lower restoration of lost height (30%) (P < 0.05). Both treatments resulted in significantly stronger vertebral bodies relative to their initial state (P < 0.05). The tamp treatment restored vertebral body stiffness to initial values, but the percutaneous vertebroplasty treatment did not (P < 0.05). CONCLUSIONS: Tamp treatment resulted in significantly greater height restoration than did percutaneous vertebroplasty, without loss of vertebral body strength or stiffness.

Aged↗
PubMed2001

Topotecan concomitant with primary brachytherapy radiation in patients with cervical carcinoma: a phase I trial.

OBJECTIVE: The aim of this study was to assess the toxicity of concomitant topotecan and radiation therapy in a Phase I study. Primary treatment for cervical carcinoma usually consists of surgery or radiation, with chemotherapy used in a neoadjuvant or concomitant fashion. There are in vitro data to suggest that topotecan is a radiosensitizing agent. METHODS: Six patients with cervical cancer were recruited to this study. All patients had completed whole pelvic radiation therapy and were scheduled for low-dose brachytherapy. The patients were administered topotecan IV during their low-dose brachytherapy. The initial dose of topotecan was 0.5 mg/m2/day for 5 days concomitant with low-dose brachytherapy for two brachytherapy applications. RESULTS: Three patients were accrued to the initial dose level. No major toxicity was noted at this dose level. Three patients were treated at the 1.0 mg/m2/day dose level; however, significant toxicity was noted at this level. (Two patients experienced grade 4 and one a grade 3 hematologic toxicity). CONCLUSION: Significant marrow toxicity was noted with concomitant topotecan and intracavitary radiation at 1.0 mg/m2/day. The maximum tolerated dose in this trial was 0.5 mg/m2/day for 5 days of topotecan concomitant with low-dose brachytherapy.

Adenocarcinoma↗
PubMed2001

Intra-arterial papaverine-induced seizures: case report and review of the literature.

BACKGROUND: Microcatheter-guided intra-arterial (IA) papaverine infusion in conjunction with balloon angioplasty is an available therapy for patients with symptomatic vasospasm after subarachnoid hemorrhage (SAH) that is refractory to hypertensive, hypervolemic therapy. However, side effects and complications have been reported in association with its use. CASE DESCRIPTION: We report on a patient who developed symptomatic vasospasm after subarachnoid hemorrhage due to rupture of a left terminal internal carotid artery (ICA) saccular aneurysm. Seven days after the hemorrhage and 4 days after surgical clipping, the patient developed aphasia and right hemiparesis due to vasospasm, which was refractory to maximal medical treatment with volume and blood pressure elevation. Cerebral angiography identified severe narrowing of distal ICA and proximal middle cerebral artery segments bilaterally. These findings partially resolved after balloon angioplasty. However, after 300 mg of IA papaverine, the patient developed generalized convulsions. This occurred despite therapeutic serum levels of phenytoin. Twenty-four hours later, after brief neurologic improvement, recurrent neurologic deficits prompted repeat papaverine administration. Seizures again occurred after the administration of 240 mg of IA papaverine and prevented administration of the full dose. The patient did not develop further seizures and her neurologic deficits continue to resolve. CONCLUSIONS: IA papaverine-induced seizures are infrequently reported. This potential complication should be considered when papaverine administration is entertained in the treatment of anterior circulation refractory symptomatic vasospasm after SAH.

Adult↗
PubMed2001

The role of natural killer cells in adenovirus-mediated p53 gene therapy.

Adenovirus-mediated gene therapy is a promising new approach for treatment of ovarian cancer. In animal models, complete elimination of cancer cells is often achieved, although the therapeutic gene has not been delivered to all these cells. This is referred to as a bystander effect, because tumor cells near those that receive the therapeutic gene are also eliminated. Several mechanisms have been proposed for the bystander effect, including intercellular communication within the tumor via gap junctions, apoptosis, antiangiogenesis, cytokines or other soluble mediators, and immunological mechanisms. There are two well-documented antitumor effector cell populations in athymic nude mice: macrophages and natural killer (NK) cells. We hypothesize that peritoneal populations of NK cells in nude mice treated with adenoviruses are involved in the observed bystander effect in this in vivo model. We investigated the role of NK cells as immunological mediators for the bystander effect using the p53 tumor suppressor as the therapeutic anticancer gene. Most ovarian cancer cell lines tested were sensitive to lysis by NK cells, although different ovarian cancer cell lines exhibited different sensitivities to NK cell-mediated lysis. To determine the importance of NK cells in the overall efficacy and in the bystander effect of gene therapy, NK cells were depleted in mice by administration of anti-NK1.1 monoclonal antibodies. To study the efficacy of NK depletion, C57BL/6 (nu/nu) mice were given injections i.v. by a single tail vein injection or i.p. with increasing doses of anti-NK1.1 IgG. All doses of anti-NK1.1 antibody, from 100-500 micrograms, essentially eliminated cytotoxic NK activity. To assess the duration of depletion after a single dose of anti-NK1.1 IgG, a time-course experiment was performed. NK 1.1 antibody was effective in completely depleting cytotoxic NK cell activity in the mice for up to 7 days, whether given as 500 micrograms (i.p.) or 200 micrograms (i.v.). Flow cytometric analysis performed on peritoneal cell populations confirmed depletion of NK cells by approximately 80%. Finally, a survival study was performed, in which animals were depleted of NK cells. In this experiment, NK cell-depleted mice were injected with anti-NK1.1 IgG, and control mice were mice were treated with normal saline. Two days later, all mice were inoculated with a lethal i.p. dose of NIH:OVCAR-3 ovarian cancer cells. After 3 days, the mice were divided into two treatment groups; one treatment group received three consecutive daily i.p. injections of Ad-CMV-p53 (SCH58500), and the second treatment group received three consecutive daily i.p. injections of control adenovirus construct, rAd-null. All of the NK cell-depleted animals, whether treated with rAd-null or with Ad-CMV-p53 (SCH58500) were dead of disease by 116 and 138 days, respectively, after initiation of adenovirus treatment, and no statistically significant difference in survival was observed (P = 0.349). A significant survival advantage was seen in control (NK-competent) mice treated with rAd-null (P = 0.04), although all were dead of disease by day 184. Importantly, control NK-competent mice treated with Ad-CMV-p53 (SCH58500) showed no tumor growth or ascites production, and all animals survived. These results indicate that immunological mechanisms involving natural killer cells play an important role in the bystander effect involving adenovirus-p53 gene therapy for ovarian cancer.

Adenoviridae↗
PubMed2000

Derivation and initial characterization of a mouse mammary tumor cell line carrying the polyomavirus middle T antigen: utility in the development of novel cancer therapeutics.

Here we describe the derivation of novel cell lines from spontaneous mammary tumors that arose in mouse mammary tumor virus-polyomavirus (MMTV-PyV) Middle T (MidT) transgenic mice. Clonal cell lines from four mixed cell populations were tested for adenovirus transducibility and sensitivity to p53 tumor suppressor gene therapy mediated by SCH58500, a replication-deficient adenovirus that expresses human p53. The MidT2-1 cell line was selected for further characterization in vitro and in vivo. This cell line carried the PyV MidT antigen, had wild-type p53 DNA, and was sensitive to suppression of proliferation by MMAC/PTEN tumor suppressor gene therapy. MidT2-1 cells gave rise to highly aggressive tumors in syngeneic FVB mice in both the mammary fat pad and the peritoneal cavity. The histopathology of MidT2-1 tumors closely resembled the histopathology of the primary transgenic tumors. Tumor growth in vivo was inhibited by p53 gene therapy or by MMAC gene therapy. In addition, combination therapy with a number of anticancer agents had synergistic or additive efficacy in vitro. In particular, MMAC gene therapy synergized with SCH58500 or paclitaxel. In the i.p. MidT2-1 tumor model p53 gene therapy enhanced the survival benefits of paclitaxel/cisplatin chemotherapy. Combination therapy has become a mainstay in cancer treatment. In this report, we use a novel transgenic mouse tumor cell line to suggest new combinations that might be explored in clinical cancer care. These include gene therapy using the tumor suppressors MMAC and p53, chemotherapy using farnesyl transferase inhibitors, the microtubule stabilizing taxanes, and the DNA synthesis disruptors gemcitabine and cisplatin. The precise biological mechanisms by which these therapies induce their antitumor effects are not fully elucidated. However, the work presented here suggests that many of these therapeutic approaches have synergistic antitumor activity when used in combination.

Adenoviridae↗
PubMed2000

Biomechanical evaluation of a new bone cement for use in vertebroplasty.

STUDY DESIGN: Comparative ex vivobiomechanical study. OBJECTIVES: To determine the strength and stiffness of osteoporotic vertebral bodies subjected to compression fractures and subsequently stabilized via bipedicular injection of one of two bone cements: one is a commercially available polymethylmethacrylate (Simplex P) and one is a proprietary glass-ceramic-reinforced BisGMA/BisEMA/TEGDMA matrix composite that is being developed for use in vertebroplasty (Orthocomp). SUMMARY OF BACKGROUND DATA: Osteoporotic compression fractures present diagnostic and therapeutic challenges for the clinician. Vertebroplasty, a new technique for treating such fractures, stabilizes vertebral bodies by injection of cement. Little is known, however, about the biomechanics of this treatment. METHODS: Five vertebral bodies (L1-L5) from each of four fresh spines were harvested from female cadavers (age, 80 +/- 5 years), screened for bone density using DEXA (t = -3.4 to -6.4), disarticulated, and compressed in a materials testing machine to determine initial strength and stiffness. The fractures then were repaired using a transpedicular injection of either Orthocomp or Simplex P and recrushed. RESULTS: For both cement treatments, vertebral body strength after injection of cement was significantly greater than initial strength values. Vertebral bodies augmented with Orthocomp recovered their initial stiffness; however, vertebral bodies augmented with Simplex P were significantly less stiff than they were in their initial condition. CONCLUSIONS: Augmentation with Orthocomp results in similar or greater mechanical properties compared with Simplex P, but these biomechanical results have yet to be substantiated in clinical studies.

Aged↗
PubMed2000

Effect of augmentation on the mechanics of vertebral wedge fractures.

STUDY DESIGN: The effect of cement augmentation of wedge-fractured vertebral bodies on spine segment compliance was studied in 16 cadaver specimens. OBJECTIVES: 1) To assess the mechanical effects of cement augmentation of vertebral wedge fractures. 2) To determine whether a new reduction/injection procedure has the same mechanical effects as the established direct injection procedure. SUMMARY OF BACKGROUND DATA: Although wedge fractures cause pain and disability in hundreds of thousands of people, few effective treatments are available. Clinical studies have shown that cement augmentation, a new procedure, effectively relieves pain and restores mobility in patients suffering from weak or fractured vertebrae. However, only a few studies have examined the mechanics of vertebral augmentation. METHODS: A wedge fracture was created in the middle vertebra of 16 three-vertebra cadaver spine segments. Neutral and full-load compliance of each fractured spine segment in flexion/extension and lateral bending were assessed by measuring the relative rotation of the vertebral bodies in response to applied moments. Eight of the fractured vertebral bodies were then augmented using direct injection, while the remaining eight fractured vertebral bodies were augmented using a combined reduction/injection procedure. Compliance of the augmented segments was then assessed. RESULTS: Augmentation significantly reduced the neutral compliance (reduction of 25% +/- 23%) (mean +/- standard deviation) and the full-load compliance (reduction of 23% +/- 20%) in flexion/extension (P < 0.005). Augmentation also significantly reduced the neutral compliance (reduction of 34% +/- 20%) and the full-load compliance (reduction of 26% +/- 17%) in lateral bending (P < 0.0001). No significant difference was found between the two procedures for compliance reduction. CONCLUSIONS: Augmentation of wedge fractures using both direct injection and reduction/injection reduces spine segment compliance significantly.

Aged↗
PubMed2000

Placebo-controlled trial of indole-3-carbinol in the treatment of CIN.

OBJECTIVE: Most precancerous lesions of the cervix are treated with surgery or ablative therapy. Chemoprevention, using natural and synthetic compounds, may intervene in the early precancerous stages of carcinogenesis and prevent the development of invasive disease. Our trial used indole-3-carbinol (I-3-C) administered orally to treat women with CIN as a therapeutic for cervical CIN. METHODS: Thirty patients with biopsy proven CIN II-III were randomized to receive placebo or 200, or 400 mg/day I-3-C administered orally for 12 weeks. If persistent CIN was diagnosed by cervical biopsy at the end of the trial, loop electrocautery excision procedure of the transformation zone was performed. HPV status was assessed in all patients. RESULTS: None (0 of 10) of the patients in the placebo group had complete regression of CIN. In contrast 4 of 8 patients in the 200 mg/day arm and 4 of 9 patients in the 400 mg/day arm had complete regression based on their 12-week biopsy. This protective effect of I-3-C is shown by a relative risk (RR) of 0.50 ((95% CI, 0. 25 to 0.99) P = 0.023) for the 200 mg/day group and a RR of 0.55 ((95% CI, 0.31 to 0.99) P = 0.032) for the 400 mg/day group. HPV was detected in 7 of 10 placebo patients, in 7 of 8 in the 200 mg/day group, and in 8 of 9 in the 400 mg/day group. CONCLUSIONS: There was a statistically significant regression of CIN in patients treated with I-3-C orally compared with placebo. The 2/16 alpha-hydroxyestrone ratio changed in a dose-dependent fashion.

Administration, Oral↗
PubMed2000

Pharmacologic testing as an adjunct to neuroendovascular procedures.

Pharmacologic testing is a method that may be employed to predict the permanent outcome of arterial embolization. Various drugs used for these tests and their differential indications are discussed. Pharmacologic testing provides an additional margin of safety and is useful as an adjunctive tool when performing embolizations of vessels supplying the head, brain, or spinal cord.

Arteries↗
PubMed1999

Biomechanical efficacy of unipedicular versus bipedicular vertebroplasty for the management of osteoporotic compression fractures.

STUDY DESIGN: Cadaveric study on the biomechanics of osteoporotic vertebral bodies augmented and not augmented with polymethylmethacrylate cement. OBJECTIVES: To determine the strength and stiffness of osteoporotic vertebral bodies subjected to compression fractures and 1) not augmented, 2) augmented with unipedicular injection of cement, or 3) augmented with bipedicular injection of cement. SUMMARY OF BACKGROUND DATA: Percutaneous vertebroplasty is a relatively new method of managing osteoporotic compression fractures, but it lacks biomechanical confirmation. METHODS: Fresh vertebral bodies (L2-L5) were harvested from 10 osteoporotic spines (T scores range, -3.7 to -8.8) and compressed in a materials testing machine to determine intact strength and stiffness. They were then repaired using a transpedicular injection of cement (unipedicular or bipedicular), or they were unaugmented and recrushed. RESULTS: Results suggest that unipedicular and bipedicular cement injection restored vertebral body stiffness to intact values, whereas unaugmented vertebral bodies were significantly more compliant than either injected or intact vertebral bodies. Vertebral bodies injected with cement (both bipedicular and unipedicular) were significantly stronger than the intact vertebral bodies, whereas unaugmented vertebral bodies were significantly weaker. There was no significant difference in loss in vertebral body height between any of the augmentation groups. CONCLUSIONS: This study suggests that unipedicular and bipedicular injection of cement, as used during percutaneous vertebroplasty, increases acute strength and restores stiffness of vertebral bodies with compression fractures.

Absorptiometry, Photon↗
PubMed1999

An in vitro biomechanical evaluation of bone cements used in percutaneous vertebroplasty.

The purpose of this study was to determine the strength and stiffness of osteoporotic vertebral bodies (VBs) subjected to compression fractures and subsequently treated with bipedicular injections of various polymethylmethacrylate cements. Ten spines were harvested from nonembalmed female cadavers (age 68.6 +/- 13.7 years) and evaluated for bone mineral density using the dual energy X-ray absorptiometry method (t-score = -2.3 +/- 2.4). The 50 VBs (L1-L5) were disarticulated, compressed in a materials testing machine to determine initial strength and stiffness, and then assigned to one of six groups. Two of these groups (n = 8, n = 9) concerned experimental cements, the results of which are not reported here. The 33 vertebral bodies in the remaining four groups were left untreated or were repaired using a transpedicular injection of one of three commercially available polymethylmethacrylate cements. These four groups were: a) no treatment (no cement, n = 8); b) Simplex P (n = 9); c) Cranioplastic (n = 8); and d) Osteobond (n = 8). The VBs were then compressed again according to the initial protocol, and posttreatment strength and stiffness were measured. Results suggested that bipedicular injection of Simplex P and Osteobond restored VB stiffness to initial values, whereas VBs injected with Cranioplastic were significantly less stiff than in their initial state. VBs injected with cement (regardless of type) were significantly stronger than they were initially.

Absorptiometry, Photon↗