Mucopolysaccharidosis type I: characterization of a common mutation that causes Hurler syndrome in Moroccan subjects

A group of 13 Moroccan patients with MPS I and their families, including three siblings and twin siblings, was screened for mutations of the alpha-L-iduronidase gene using fluorescence-assisted mismatch analysis (FAMA) and cycle sequencing of PCR products. The P533R mutation, which is rare in Europeans, was identified in 92% of mutant alleles (24/26). This is the highest frequency of this mutation detected in patients with Hurler syndrome. None of the patients carried the W402X or Q70X alleles, the most common MPS I mutations in Europeans. These results suggest that the P533R mutation constitutes the genetic lesion which results in MPS I in people of Moroccan descent and provides yet more evidence for the uneven geographical distribution of mutations in MPS I.

Progressive vascular remodeling and reduced neointimal formation after placement of a thermoelastic self-expanding nitinol stent in an experimental model

Despite the improvements afforded by intracoronary stenting, restenosis remains a significant problem. The optimal physical properties of a stent have not been defined. We compared the vascular response to a thermoelastic self-expanding nitinol stent with a balloon-expandable tubular slotted stainless steel stent in normal porcine coronary arteries. Twenty-two stents (11 nitinol and 11 tubular slotted) were implanted in 11 miniature swine. The nitinol stents were deployed using the intrinsic thermal properties of the metal, without adjunctive balloon dilation. The tubular slotted stents were implanted using a noncompliant balloon with a mean inflation pressure of 12 atm. Intravascular ultrasound (IVUS) and histology were used to evaluate the vascular response to the stents. The mean cross-sectional area (CSA) of the nitinol stents (mm2) as measured by IVUS increased from 8.13 +/- 1.09 at implant to 9.10 +/- 0.99 after 28 days (P = 0.038), while the mean CSA of the tubular slotted stents was unchanged (7.84 +/- 1.39 mm2 vs. 7.10 +/- 1.07 mm2, P = 0.25). On histology at 3 days, the tubular slotted stents had more inflammatory cells adjacent to the stent wires (5.7 +/- 1.5 cells/0.1 mm2) than the nitinol (3.9 +/- 1.3 cells/0.1 mm2, P = 0.016). The tubular slotted also had increased thrombus thickness (83 +/- 85 microm) than the nitinol stents (43 +/- 25 microm, P = 0.0014). After 28 days, the vessel injury score was similar for the nitinol (0.6 +/- 0.3) and the tubular slotted (0.5 +/- 0.1, P = 0.73) designs. The mean neointimal area (0.97 +/- 0.46 mm2 vs. 1.96 +/- 0.34 mm2, P = 0.002) and percent area stenosis (15 +/- 7 vs. 33 +/- 7, P = 0.003) were significantly lower in the nitinol than in the tubular slotted stents, respectively. We conclude that a thermoelastic nitinol stent exerts a more favorable effect on vascular remodeling, with less neointimal formation, than a balloon-expandable design. Progressive intrinsic stent expansion after implant does not appear to stimulate neointimal formation and, therefore, may provide a mechanical solution to prevent in-stent restenosis.

Boron modulates extracellular matrix and TNF alpha synthesis in human fibroblasts

Boric acid was not mitogenic for human fibroblasts and it did not change cell viability until 0.5% (w/v). Boric acid treatment affected the metabolism of human dermal fibroblasts in culture, decreasing the synthesis of extracellular matrix macromolecules such as proteoglycans, collagen, and total proteins. It also increased the release of these molecules into the culture medium. The principal proteins secreted into the medium after boric acid treatment had molecular masses of 90, 70, 58, 49, and 43 kDa and faint bands were detected by electrophoresis between 14 and 30 kDa. hsp 70 and TNF alpha were detected among the secreted proteins by immunoblotting, and the amount of TNF alpha released was quantified by radioimmunoassay. Total mRNA levels were higher after boric acid treatment and peaked after 6 h of treatment. TNF alpha mRNA was undetectable in unstimulated fibroblasts and two TNF alpha mRNA bands were detected after stimulation: immature mRNA (4.8 kb) and mature TNF alpha mRNA (1.9 kb). Thus, the effects of boric acid observed in wound repair in vivo may be due to TNF alpha synthesis and secretion.

Establishment of a mouse Sertoli cell line producing rat androgen-binding protein (ABP)

The ultimate goal of this study was to compare the fate of rat testicular germ cells cocultured with mouse Sertoli cells that either do or do not produce rat androgen-binding protein (ABP). As a first step, we stably transfected a rat ABP expression construct into an immortalized mouse Sertoli cell line (TM4), which does not produce ABP when growing on plastic without hormones. The transfection of the pRc/CMV- rat ABP cDNA expression vector containing a neomycin resistance gene was made by either the liposome method (Dotap) or by polyethyleneimine transfection (PEI) into TM4 cell cultures. Neomycin-resistant clones were selected by adding Geneticin to the culture medium for 3 weeks. Analysis of over 25 clones revealed the presence of recombinant rat ABP when cell extracts and culture media were probed with a rabbit polyclonal antibody raised against rat testicular ABP, indicating the translation and secretion of a protein similar to rat testicular ABP. Transfected TM4 cells maintain the secretion of rat ABP for more than 40 days, with immunopositive rat ABP localized within cytoplasmic granules in the Golgi region and along cytoplasmic processes in TM4 transfected with either vector. Electron microscopic study revealed a higher development of cytoplasmic organelles involved in protein secretion.

Numerical simulation of vertical cavity surface emitting lasers

The semiconductor laser simulator MINILASE is being extended to simulate vertical cavity surface emitting lasers (VCSELs). The electronic system analysis for VCSELs is identical to that for edge emitting lasers. A brief discussion of the capabilities of MINILASE in this domain will be presented. In order to simulate VCSELs, the optical mode solver in MINILASE must be extended to handle the reduced index guiding and significant gain guiding typical of many VCSEL structures. A new approach to solving the optical problem which employs active cavity modes rather than the standard passive cavity modes is developed. This new approach results in an integral eigenvalue equation in required gain amplitudes and corresponding modal fields. Sample results from an early implementation of a gain eigenvalue solver are shown to clarify the possibilities of this approach.

Prognostic significance of glutathione S-transferase pi expression and subcellular localization in human gliomas

The glutathione S-transferase (GST)-pi gene is overexpressed in many human cancers and preneoplastic lesions and is associated with failure of cancer chemotherapy and poor patient survival. Although GST-pi overexpression in tumors of the central nervous system has been observed, the prognostic and/or clinical relevance of this overexpression has, to date, not been investigated. In this study, we analyzed the level of GST-pi expression and its subcellular localization in 61 primary gliomas and correlated the results with tumor histology, patient age, and patient survival. We observed a strong positive correlation between the level of GST-pi expression and tumor grade and between the presence of GST-pi in glioma cell nuclei and patient age. Univariate and multivariate Cox regression analyses and Kaplan-Meier curves showed the level of GST-pi expression and its nuclear localization to be inversely correlated with patient survival. Relative risk for death of patients with high versus low tumor GST-pi expression was 3.2 (P = 0.0069) by univariate analysis and 2.6 (P = 0.036) by multivariate analysis. The relative risk of death associated with the presence of nuclear GST-pi in glioma cells was 3.9 (P = 0.0001) by univariate analysis and 4.4 (P < 0.0001) by multivariate analysis. These data indicate that high GST-pi expression in tumor cells and the presence of the GST-pi protein in tumor cell nuclei are associated with clinically more aggressive gliomas and are strong predictors of poor patient survival.

Renal and blood pressure effects of moxonidine and clonidine in spontaneously hypertensive rats

Recently we could demonstrate that the imidazoline receptor agonist moxonidine exerts specific renal effects in Sprague Dawley rats [Hohage et al. 1997]. Interestingly, the effects of this compound are attenuated in one kidney-one clip hypertensive rats [Li et al. 1994]. In this study, we therefore investigated the effects of moxonidine as compared to clonidine in genetically determined spontaneously hypertensive rats. Moxonidine in a concentration of 0.5 mg/kg b.w.i.v. induced a significant and long-lasting increase of both urine flow from 11.9 +/- 2.1 microliters/min x 100 g b.w. to 50.3 +/- 12.5 microliters/min x 100 g b.w. and of Na(+)-excretion from 2.2 +/- 0.5 mumol/min x 100 g b.w. to 8.4 +/- 1.9 mumol/min x 100 g b.w. In contrast to moxonidine, the effects of clonidine (0.5 mg/kg b.w.i.v.) on urine flow and Na(+)-excretion were negligible. The antagonists idazoxan, effaroxan and rauwolscine abolished the effects of moxonidine on urine flow and Na(+)-excretion, whereas 4-aminopyridine, phenformine and 1,2,3,4-tetrahydro-9-aminoacridine, which have been described to interact with imidazoline binding sites, had no effect. Addition of the antagonists idazoxan, effaroxan and rauwolscine attenuated the initial blood pressure increase immediately after intravenous application, whereas 4-aminopyridine, phenformine and 1,2,3,4-tetrahydro-9-aminoacridine had no influence on this side-effect. Our results provide further evidence that imidazoline receptor agonists such as moxonidine exhibit renal effects, different from the modulation in urine flow and Na(+)-excretion following renal alpha 2 adrenoceptor stimulation. An upregulation of imidazoline receptors in hypertension may contribute to the effects observed.

p53 immunohistochemical staining predicts residual disease after chemoradiation in patients with high-risk rectal cancer

This study was conducted to investigate the value of p53 immunohistochemical staining of pretreatment biopsy specimens in predicting the response of rectal cancer to chemoradiation. The study group comprised 42 patients with high-risk rectal cancer treated between July 1990 and July 1995 with a preoperative chemoradiation regimen of 45 Gy of external-beam irradiation and continuous-infusion 5-fluorouracil followed by surgical resection. p53 immunohistochemical staining was performed on pretreatment biopsy specimens. p53 immunohistochemical staining pattern and standard clinical and pathological parameters were correlated with extent of residual cancer in the surgical specimen. Twenty tumors were positive for p53 on immunohistochemical staining, 19 were negative, and 3 were focally positive. Thirteen patients experienced a complete response to chemoradiation. Aberrant p53 protein accumulation, as measured by immunohistochemical staining, correlated inversely with a complete pathological response to chemoradiation (P = 0.005; correlation coefficient = -0.43) and directly with an increased likelihood of residual cancer in the lymph nodes of surgical specimens (P = 0.02; correlation coefficient = 0.39). p53 immunohistochemical staining of pretreatment biopsy specimens correlates with the extent of residual disease after chemoradiation in patients with high-risk rectal cancer.

Screening for colorectal cancer. A comparison of 3 fecal occult blood tests

BACKGROUND

Colorectal cancer is the second leading cause of cancer deaths in the United States. Fecal occult blood testing has become a standard screening test for large-bowel cancers in the average asymptomatic population. Performance characteristics of the test and physician and participant compliance are the 2 major elements that impact the success of screening and early detection.

OBJECTIVES

To evaluate the nonhydrated Hemoccult, rehydrated Hemoccult, and Hemoccult SENSA tests (SmithKline Diagnostics Inc, Palo Alto, Calif) and to assess participant and physician compliance.

METHODS

A mass community-based screening study in an urban setting. Kits were distributed by a local pharmacy and at community sites. Diagnostic tests were completed through physicians' offices and clinics. Participants were asymptomatic and aged 50 years or older. Those who tested positive were advised to follow up with a physician.

RESULTS

An overall positivity rate of 16% was reported for the 8293 kits that were processed. Rehydrated Hemoccult had a positivity rate of 15%; Hemoccult SENSA, 7%; and nonhydrated Hemoccult, 5%. The positive predictive value of nonhydrated Hemoccult was 14%; rehydrated Hemoccult, 7%; and Hemoccult SENSA, 11%. Of those who tested positive, 59% had a colonoscopy or flexible sigmoidoscopy and double-contrast barium enema examination on follow-up. Recommended follow-up was more frequent for those who consulted a gastroenterologist.

CONCLUSIONS

Rehydrated Hemoccult yielded a higher positivity rate and lower positive predictive value than either Hemoccult SENSA or nonhydrated Hemoccult. Hemoccult SENSA approached the positive predictive value of nonhydrated Hemoccult. Adequacy of follow-up of patients testing positive for fecal occult blood needs improvement.

Effect of boric acid solution on cartilage metabolism

Pelvic cartilage of chick embryo was used to demonstrate that presence of boron in culture medium decreases synthesis of proteoglycans, collagen and total proteins but on the other hand increases the release of these macromolecules. However, when glucose concentration in culture medium is brought to 22mM, the synthesis decrease is no longer observed, whereas release increase persists. Proteins released into the culture medium included heat shock proteins (70 hsp) and tumor necrosis factor alpha (TNF alpha). The amount of phosphorylated proteins was enhanced in presence of boron while endoprotease activity in cartilage and in culture medium was significantly augmented. The in vitro effects of boric acid may explain its in vivo effect on wound healing.

TPDC-FuHu chemotherapy for the treatment of recurrent metastatic brain tumors

PURPOSE

To evaluate a combination of thioguanine, procarbazine, dibromodulcitol, CCNU (CCNU), fluorouracil, and hydroxyurea (TPDC-FuHu), designed to improve the efficacy of CCNU, in the treatment of recurrent metastatic brain tumors.

PATIENTS AND METHODS

One hundred fifteen patients with progressive or recurrent metastatic brain tumors that failed to respond to surgery and/or radiation therapy were enrolled onto a multicenter prospective study between 1989 and 1995. Patients received TPDC-FuHu in a repeated cycle every 6 weeks until recurrence or until they completed six courses.

RESULTS

Ninety-seven patients were assessable at the end of the study. Forty-eight had lung cancer (39 non-small-cell [NSCLC] and nine small-cell [SCLC]), 28 had breast cancer, nine had melanoma, and 12 had adenocarcinoma of different origins (three colon, two kidney, one bladder, one stomach, and five of unknown origin). The response and stable disease (SD) rate (overall response rate) was 52%, 66%, 60%, and 22% in patients with NSCLC, SCLC, breast cancer, and melanoma, respectively. Median time to progression (MTP) was 12, 26, 12, and 6 weeks, respectively, for the four groups. Side effects were mild to moderate in the majority of patients. Severe myelosuppression (grade 4) occurred in only 11% of the patients.

CONCLUSION

TPDC-FuHu chemotherapy is an active treatment against recurrent brain metastases from breast cancer and SCLC, and to a lesser extent from NSCLC. This regimen is well tolerated and has acceptable toxicity.

Cumulus expansion initiates physical and developmental autonomy of the oocyte

As meiosis is initiated and the oogonium is transformed into a primary oocyte, the female germ cell becomes intimately invested by a single squamous layer of sex cord epithelium. As the follicle cell population expands during the initial stages of the ovarian cycle, oocyte and follicle cells become increasingly connected to one another by one of the most extensive populations of gap junctions documented in any epithelium (reviewed in Larsen &amp; Wert, 1988).

[Assessment and diagnosis of transient ischemic attacks]

Transient ischemic attacks (TIA) are defined as acute, retinal or focal-cerebral neurological symptoms, resulting from vascular disease, which resolve in less than 24 hours. Typical clinical signs are transient visual obscuration, sudden weakness of one arm or leg, loss of speech, and dizzy spells. These patients run a considerable risk of stroke; hence rapid diagnosis and treatment are mandatory. Differential diagnosis includes transient global cerebral function loss, non-vascular transient focal attacks, as well as extracerebral causes of transient neurological symptoms. The following basic investigations are necessary for most patients with TIA: simple laboratory work-up, extra- and transcranial doppler/duplex-ultrasonography, cardiological examination and CT-scan. Angiography and MR-angiography are reserved for specific questions.

Government policy influences on rangeland conditions in the United States: A case example

Since the early 1970s the Bureau of Land Management (BLM) and the Forest Service have emphasized the monitoring approach in managing their rangelands. After a 5-year period of intensive monitoring, stocking rate and other management actions are typically adjusted, depending on whether a definite downward or upward trend in range condition is observed. Examining the Afton Allotment on BLM land in southcentral New Mexico, we demonstrate serious flaws in the monitoring approach and other BLM grazing policies. Monitoring reflects past management but does not consider the future. Perverse incentives for permittees to maximize permit value rather than sustain the forage base still remain in place. The "Range Reform '94" proposals by the U.S. Department of the Interior do not address these incentives and other flaws in public land policy. We would reform federal grazing land policy by coupling grazing fees to grazing intensity. Ranchers choosing conservative sustainable grazing intensities would pay low fees, whereas those choosing heavy grazing intensities would be charged higher rates. We would also implement other reforms: making livestock grazing permits transferable to other uses, discontinuing subsidies, eliminating restrictions on nonuse, offering incentives for public land investment, and establishing a biodiversity fund.

Policy roots of land degradation in the arid region of the United States: An overview

The roots of land degradation in the arid region of the United States are set firmly in the era of open range conditions that led to the depletion of rangeland resources in the late 19th and early 20th centuries. Upon closure of the open range and establishment of the U.S. Forest Service and the Bureau of Land Management, public lands in the arid region were protected from the classic tragedy of the commons. Private lands, in turn, fell under the stewardship guidance of such organizations as the Soil Conservation Service, the Agricultural Stabilization and Conservation Service, and the Cooperative Extension Service. Despite these institutional protections, arid land degradation continues at an ecologically and socially unacceptable rate. The most likely explanation for this degradation resides in the institutions and public policies that shape and control livestock grazing. Flaws and disincentives endemic to the grazing permit system have encouraged destructive grazing. Federal subsidies to public- and private-land ranchers have encouraged rangeland stocking rates in excess of carrying capacity on economically and ecologically marginal lands and consistently favored unsound land management practices over superior ones. Policy-generated distortions of market forces have lead to unanticipated and environmentally undesirable land use outcomes. Land management, technical support, and educational institutions have also inadvertently contributed to land degradation in the arid region. Reversing the trend of land degradation in an advanced country like the United States demands that we understand the role of public policy in land use outcomes and that we structure future public policies in accordance with the lessons of recent history.

Stimulation of translation by reactive oxygen species in a cell-free system

Wheat germ lysate was used as a model system for in vitro translation. We show that an increase of the exchange surface between the reaction mixture and the atmosphere enhanced the amount of incorporated cysteine, indicating that early arrest of protein synthesis previously observed in such a system was due to oxygen starvation in the reaction mixture. This hypothesis was confirmed since the amount of proteins synthesized and the rate of translation increased when oxygen was added. We show that an addition of hydrogen peroxide to the translation mixture had the same effect as oxygen, allowing us to postulate that stimulation could be due to a common property between both molecules: the oxidizing behaviour. Free radicals in in vitro translation were believed to be involved since the utilization of iron chelating agents inhibited translation. This hypothesis was emphasized by the positive effect of a free radical generating system and the negative effect of free radical scavengers. These experiments suggest that the superoxide radical plays an important role in in vitro translation.

Expression of secreted recombinant human insulin-like growth factor-II (IGF-II) in Chinese hamster ovary cells

Chinese hamster ovary (CHO-KI) cells were cotransfected with a plasmid pcDNAI containing the human preproinsulin-like growth factor II cDNA linked downstream to the human cytomegalovirus promoter and with a plasmid containing the neomycin resistance gene (pMAM-neo). CHO neo+ were selected by growth in medium supplemented with G418 geneticin. After amplification, the neomycin-resistant clones were screened for IGF-II production. IGF-II produced was identified by dot blot and quantified by ELISA. The clones C24, C40 and C94 secreted IGF-II at about 350-400 ng per 10(6) cells per day. DNA analysis of C24 and C40 CHO cells by PCR demonstrated the presence of the IGF-II construct in the transfected cells, presumably integrated into the chromosomal DNA. IGF-II produced by CHO cells and purified by RP-HPLC was a mitogen for MCF-7 stimulating mitosis 2-fold.