Staged complex abdominal wall hernia repair in morbidly obese patients.

PURPOSE: The repair of complex abdominal wall hernias in morbidly obese patients is often associated with a higher risk of complications and hernia recurrences. Improvement in obesity and its associated metabolic complications are hypothesized to improve hernia repair outcomes. This study analyzes outcomes from morbidly obese patients who underwent bariatric surgery with staged complex abdominal wall reconstruction at Creighton University Medical Center (CUMC). METHODS: This retrospective study included morbidly obese patients with complex abdominal wall hernia, who underwent bariatric surgery with staged abdominal wall reconstruction. Data points collected included patient demographics, obesity-related co-morbidities, pre-operative BMI, EBMIL at 12 months, hernia characteristics, postoperative complications, BMI at time of hernia repair, and hernia recurrence. RESULTS: Twelve patients with an average BMI of 48 and complex abdominal wall hernias (mean width 14.0 cm) met inclusion criteria. Seven patients (58%) had significant loss of domain. Bariatric procedures included six laparoscopic sleeve gastrectomies (LSG), three laparoscopic Roux-en-Y gastric bypasses (LRNYGB), and three revisional procedures (2 vertical band gastroplasties to LRNYGB and 1 LRNYGB revision). At 12-month follow-up, the mean excess BMI loss (EBMIL) was 64.6%. The average time to staged complex abdominal wall reconstruction was 22.3 months. Two non-elective hernia repairs were performed due to one incarceration and one strangulation. There were no recurrences after an average follow-up of 21.9 months. CONCLUSIONS: In this study, staged mesh repair of complex abdominal wall hernias after bariatric surgery in morbidly obese patients was associated with acceptable morbidity and no hernia recurrences at approximately 1.5 year follow-up.

Non-canonical NFκB mutations reinforce pro-survival TNF response in multiple myeloma through an autoregulatory RelB:p50 NFκB pathway.

Environmental drug resistance constitutes a serious impediment for therapeutic intervention in multiple myeloma. Tumor-promoting cytokines, such as tumor necrosis factor (TNF), induce nuclear factor-κB (NFκB)- driven expression of pro-survival factors, which confer resistance in myeloma cells to apoptotic insults from TNF-related apoptosis-inducing ligand (TRAIL) and other chemotherapeutic drugs. It is thought that RelA:p50 dimer, activated from IκBα-inhibited complex in response to TNF-induced canonical NFκB signal, mediates the pro-survival NFκB function in cancerous cells. Myeloma cells additionally acquire gain-of-function mutations in the non-canonical NFκB module, which induces partial proteolysis of p100 into p52 to promote RelB:p52/NFκB activation from p100-inhibited complex during immune cell differentiation. However, role of non-canonical NFκB signaling in the drug resistance in multiple myeloma remains unclear. Here we report that myeloma-associated non-canonical aberrations reinforce pro-survival TNF signaling in producing a protracted TRAIL-refractory state. These mutations did not act through a typical p52 NFκB complex, but completely degraded p100 to reposition RelB under IκBα control, whose degradation during TNF signaling induced an early RelB:p50 containing NFκB activity. More so, autoregulatory RelB synthesis prolonged this TNF-induced RelB:p50 activity in myeloma cells harboring non-canonical mutations. Intriguingly, TNF-activated RelB:p50 dimer was both necessary and sufficient, and RelA was not required, for NFκB-dependent pro-survival gene expressions and suppression of apoptosis. Indeed, high RelB mRNA expressions in myeloma patients correlated with the augmented level of pro-survival factors and resistance to therapeutic intervention. In sum, we provide evidence that cancer-associated mutations perpetuate TNF-induced pro-survival NFκB activity through autoregulatory RelB control and thereby exacerbate environmental drug resistance in multiple myeloma.

Tumour necrosis factor-alpha and nitric oxide response in different categories of tuberculosis patients.

OBJECTIVE: To compare the magnitude of tumour necrosis factor alpha (TNF-α) and nitric oxide (NO) response in different categories of active tuberculosis (TB) patients by ex vivo experiment. DESIGN: New, relapsed (recurrent), miliary and pleural effusion TB cases were recruited with matched healthy controls. TNF-α and NO were measured from the culture supernatant of peripheral blood monocytes derived from cases and controls with and without challenge with live Mycobacterium tuberculosis H37Rv. RESULTS: TNF-α and NO production varied significantly among the different categories of TB patients. The magnitude was highest among patients with pleural effusion and lowest in miliary TB cases. In between, progressive decreases in response were noted in new and relapse cases. Overall, positive correlations between TNF-α and NO were noted among the diseased and healthy groups. CONCLUSION: Distinct TNF-α and NO levels appear to be associated with different clinical forms of TB and might help to assess prognosis and contribute to a better understanding of underlying immunopathological mechanisms.

Microhydration of X2 gas (X = Cl, Br, and I): a theoretical study on X2.nH2O clusters (n = 1-8).

Structure and properties of hydrated clusters of halogen gas, X2.nH2O (X = Cl, Br, and I; n = 1-8) are presented following first principle based electronic structure theory, namely, BHHLYP density functional and second-order Moller-Plesset perturbation (MP2) methods. Several geometrical arrangements are considered as initial guess structures to look for the minimum energy equilibrium structures by applying the 6-311++G(d,p) set of the basis function. Results on X2-water clusters (X = Br and I) suggest that X2 exists as a charge separated ion pair, X+delta-X-delta in the hydrated clusters, X2.nH2O (n > or = 2). Though the optimized structures of Cl2.nH2O clusters look like X2.nH2O (X = Br and I) clusters, Cl2 does not exist as a charge separated ion pair in the presence of solvent water molecules. The calculated interaction energy between X2 and solvent water cluster increases from Cl2.nH2O to I2.nH2O clusters, suggesting solubility of gas-phase I2 in water to be a maximum among these three systems. Static and dynamic polarizabilities of hydrated X2 clusters, X2.nH2O, are calculated and observed to vary linearly with the size (n) of these water clusters with correlation coefficient >0.999. This suggests that the polarizability of the larger size hydrated clusters can be reliably predicted. Static and dynamic polarizabilities of these hydrated clusters grow exponentially with the frequency of an external applied field for a particular size (n) of hydrated cluster.

In vivo radioprotection by 5-aminosalicylic acid.

The radioprotective effect of 5-aminosalicylic acid (5ASA) was investigated in mouse bone marrow. The present study was aimed at investigating the radioprotective effect of pre-irradiation treatment with 5ASA against a range of whole-body lethal (8-11 Gy) and sublethal (1-4 Gy) doses of gamma-radiation (RT) in adult Swiss albino mice. Protection against lethal irradiation was evaluated from 30-day mouse survival and against sublethal doses was assessed from chromosomal aberrations in the bone marrow 24 h after irradiation. An intraperitoneal injection of 5ASA at a dose of 25mg/kg body weight (b. wt.) 30 min before lethal RT increased survival, giving a dose modification factor (DMF) of 1.08. Injection of 5ASA (25 mg/kg b. wt.) 60 or 30 min before or within 15 min after 3 Gy whole body RT resulted in a significant decrease in the radiation-induced aberrant metaphases, at 24 h post-irradiation. Maximum effect was seen when the drug was administered 30 min before irradiation. 5ASA (25 mg/kg b. wt.) significantly reduced the number of aberrant metaphases and the different types of aberrations at all the radiation doses (1-4 Gy) tested, giving a DMFs of 1.43 for number of aberrant metaphases. 5ASA pretreatment also significantly enhanced the endogenous spleen colonies in mouse exposed to 11 Gy RT. Pretreatment with 5ASA, protected plasmid DNA (pGEM-7Zf) against breakage induced by RT and Fenton reactants. Using nanosecond pulse radiolysis technique, the bimolecular rate constant of the reaction of 5ASA with hydroxyl radical was found to be 6.7x10(9)M(-1)s(-1). The p53 and p21 protein levels of bone marrow and spleen were evaluated to identify the specific molecular mechanisms. Both p53 and p21 increased 24h after 6 Gy irradiation, while treatment with 5ASA inhibited this RT-induced increase. Therefore, the present data suggest that 5ASA pretreatment decreases death caused by RT-induced gastrointestinal and hemopoeitic syndromes. The proposed mechanism of radioprotection by 5ASA is through the inhibition of damage to DNA, lipids, and proteins; and prevention of RT-induced increased expression of p53 and p21.

Rotational diffusion of organic solutes in surfactant-block copolymer micelles: role of electrostatic interactions and micellar hydration.

Rotational diffusion of a cationic solute rhodamine 110 and a neutral solute 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole, DMDPP has been examined in the surfactant-block copolymer system of sodium dodecyl sulfate (SDS) and poly(ethylene oxide)20-poly(propylene oxide)70-poly(ethylene oxide)20 (P123). In this study, the mole ratio of SDS to P123 was varied from 0 to 5 in steps of one unit, to investigate the role of electrostatic interactions and micellar hydration on solute rotation. It has been noticed that there is a significant enhancement in the average reorientation time of rhodamine 110, when [SDS]/[P123] increased from 0 to 1. This has been rationalized on the basis of migration of rhodamine 110 from the interfacial region of P123 micelles to the palisade layer (corona region) due to the electrostatic interaction with negatively charged head groups of SDS, whose tails are embedded in the polypropylene oxide core. Further increase in the mole ratio of SDS to P123 has resulted in only a marginal decrease in the average reorientation time of rhodamine 110, which is probably due to the solute molecule experiencing a microenvironment similar to the interfacial region of SDS micelles. In contrast, a gradual decrease has been observed in the average reorientation time of DMDPP with [SDS]/[P123], which is due to the increase in hydration levels in the palisade layer (corona region) of the micelle. These explanations are consistent with the structure of the SDS-P123 micellar system that has been deduced from neutron scattering and viscosity measurements recently.

Free radical scavenging reactions of sulfasalazine, 5-aminosalicylic acid and sulfapyridine: mechanistic aspects and antioxidant activity.

Reactions of sulfasalazine (SAZ) and its metabolites, 5-aminosalicylic acid (5-ASA) and sulfapyridine (SP), with various oxidizing and reducing free radicals (hydroxyl, haloperoxyl, one-electron oxidizing, lipid peroxyl, glutathiyl, superoxide, tryptophanyl, etc.) have been studied to understand the mechanistic aspects of its action against free radicals produced during inflammation. Nanosecond pulse radiolysis technique coupled with transient spectrophotometry has been used for in situ generation of free radicals and to follow their reaction pathways. The transients produced in these reactions have been assigned and radical scavenging rate constants have been measured. In addition to scavenging of various primary and secondary free radicals by SAZ, 5-ASA and SP, 5-ASA has also been observed to efficiently scavenge radicals of biomolecules. 5-ASA has been found to be the active moiety of SAZ involved in the scavenging of oxidizing free radicals whereas reduction of SAZ produced molecular radical anion. The study suggests that free radical scavenging activity of 5-ASA may be a major path of pharmacological action of SAZ against inflammatory bowel diseases (IBD).

Sirolimus: a new immunosuppressant.

Though organ transplantation has evolved in many a ways over the years, it is not without the disadvantage of causing rejections. Cyclosporin, azathioprine and corticosteroids are time tested and efficacious; however each is accompanied with its own array of disadvantages. Sirolimus is a relatively new immunosuppressant isolated from a macrolide antibiotic. It may have a beneficial role in prophylaxis of rejection as well as treatment of refractory rejection. It also has antifungal, antitumor and anti-smooth muscle proliferative roles.

Camptothecin induced mitochondrial dysfunction leading to programmed cell death in unicellular hemoflagellate Leishmania donovani.

The parasites of the order kinetoplastidae including Leishmania spp. emerge from most ancient phylogenic branches of unicellular eukaryotic lineages. In their life cycle, topoisomerase I plays a significant role in carrying out vital cellular processes. Camptothecin (CPT), an inhibitor of DNA topoisomerase I, induces programmed cell death (PCD) both in the amastigotes and promastigotes form of L. donovani parasites. CPT-induced cellular dysfunction in L. donovani promastigotes is characterized by several cytoplasmic and nuclear features of apoptosis. CPT inhibits cellular respiration that results in mitochondrial hyperpolarization taking place by oligomycin-sensitive F0-F1 ATPase-like protein in leishmanial cells. During the early phase of activation, there is an increase in reactive oxygen species (ROS) inside cells, which causes subsequent elevation in the level of lipid peroxidation and decrease in reducing equivalents like GSH. Endogenous ROS formation and lipid peroxidation cause eventual loss of mitochondrial membrane potential. Furthermore, cytochrome c is released into the cytosol in a manner independent of involvement of CED3/CPP32 group of proteases and unlike mammalian cells it is insensitive to cyclosporin A. These events are followed by activation of both CED3/CPP32 and ICE group of proteases in PCD of Leishmania. Taken together, our study indicates that different biochemical events leading to apoptosis in leishmanial cells provide information that could be exploited to develop newer potential therapeutic targets.

Testosterone inhibits early atherogenesis by conversion to estradiol: critical role of aromatase.

The effects of testosterone on early atherogenesis and the role of aromatase, an enzyme that converts testosterone to estrogens, were assessed in low density lipoprotein receptor-deficient male mice fed a Western diet. Castration of male mice increased the extent of fatty streak lesion formation in the aortic origin compared with testes-intact animals. Administration of anastrazole, a selective aromatase inhibitor, to testes-intact males increased lesion formation to the same extent as that observed with orchidectomized animals. Testosterone supplementation of orchidectomized animals reduced lesion formation when compared with orchidectomized animals receiving the placebo. This attenuating effect of testosterone was not observed when the animals were treated simultaneously with the aromatase inhibitor. The beneficial effects of testosterone on early atherogenesis were not explained by changes in lipid levels. Estradiol administration to orchidectomized males attenuated lesion formation to the same extent as testosterone administration. Aromatase was expressed in the aorta of these animals as assessed by reverse transcription-PCR and immunohistochemistry. These results indicate that testosterone attenuates early atherogenesis most likely by being converted to estrogens by the enzyme aromatase expressed in the vessel wall.

Leishmania plasma membrane Mg2+-ATPase is a H+/K+-antiporter involved in glucose symport. Studies with sealed ghosts and vesicles of opposite polarity.

Experiments from other laboratories conducted with Leishmania donovani promastigote cells had earlier indicated that the plasma membrane Mg2+-ATPase of the parasite is an extrusion pump for H+. Taking advantage of the pellicular microtubular structure of the plasma membrane of the organism, we report procedures for obtaining sealed ghost and sealed everted vesicle of defined polarity. Rapid influx of H+ into everted vesicles was found to be dependent on the simultaneous presence of ATP (1 mm) and Mg2+ (1 mm). Excellent correspondence between rate of H+ entry and the enzyme activity clearly demonstrated the Mg2+-ATPase to be a true H+ pump. H+ entry into everted vesicle was strongly inhibited by SCH28080 (IC50 = approximately 40 microm) and by omeprazole (IC50 = approximately 50 microm), both of which are characteristic inhibitors of mammalian gastric H+,K+-ATPase. H+ influx was completely insensitive to ouabain (250 microm), the typical inhibitor of Na+,K+-ATPase. Mg2+-ATPase activity could be partially stimulated with K+ (20 mm) that was inhibitable (>85%) with SCH28080 (50 microm). ATP-dependent rapid efflux of 86Rb+ from preloaded vesicles was completely inhibited by preincubation with omeprazole (150 microm) and by 5,5'-dithiobis-(2-nitrobenzoic acid) (1 mm), an inhibitor of the enzyme. Assuming Rb+ to be a true surrogate for K+, an ATP-dependent, electroneutral stoichiometric exchange of H+ and K+(1:1) was established. Rapid and 10-fold active accumulation of [U-(14)C]2-deoxyglucose in sealed ghosts could be observed when an artificial pH gradient (interior alkaline) was imposed. Rapid efflux of [U-(14)C]d-glucose from preloaded everted vesicles could also be initiated by activating the enzyme, with ATP. Taken together, the plasma membrane Mg2+-ATPase has been identified as an electroneutral H+/K+ antiporter with some properties reminiscent of the gastric H+,K+-ATPase. This enzyme is possibly involved in active accumulation of glucose via a H+-glucose symport system and in K+ accumulation.

Molecular cytogenetic analysis of uterine leiomyoma and leiomyosarcoma by comparative genomic hybridization.

Uterine leiomyomata are among the most common of human neoplasms and are associated with abnormal uterine bleeding, infertility, and abdominal pain. Uterine leiomyosarcomata are presumed to be the malignant counterpart to uterine leiomyomata and are very rare. Transformation of uterine leiomyoma (ULM) into uterine leiomyosarcoma (ULMS) is yet to be conclusively confirmed, and each type of tumor may represent a distinct genetic entity. We used comparative genomic hybridization (CGH) to evaluate DNA sequence copy-number changes in 12 specimens of ULM and 8 of ULMS. CGH analysis of ULM demonstrated chromosomal imbalances in 8 of 12 (66. 7%) specimens. The most frequent ULM gains were observed at 9q34 (a novel finding) and on chromosome 19. Other ULM imbalances included gains and losses of chromosome 1p, losses on 7q, and gains on 12q. All ULMS specimens demonstrated chromosomal aberrations. Chromosome 1 imbalances were very prominent. The most frequent losses were detected on 14q and 22q. Losses on 14q are rarely seen in other types of leiomyo-sarcoma and may be a distinctive feature of ULMS. Gains on chromosomes 8, 17, and X were observed in half the cases and were accompanied by high-level amplification. Other chromosome arms overrepresented included 12q and 19p. The absence of specific anomalies common to all ULM and ULMS argues against their being benign-malignant counterparts.

High intracellular level of guanosine tetraphosphate in Mycobacterium smegmatis changes the morphology of the bacterium.

Almost one-third of the world population today harbors the tubercle bacillus asymptomatically. It is postulated that the morphology and staining pattern of the long-term persistors are different from those of actively growing culture. Interestingly, it has been found that the morphology and staining pattern of the starved in vitro population of mycobacteria is similar to the persistors obtained from the lung lesions. In order to delineate the biochemical characteristics of starved mycobacteria, Mycobacteria smegmatis was grown in 0.2% glucose as a sole carbon source along with an enriched culture in 2% glucose. Accumulation of the stringent factor guanosine tetraphosphate (ppGpp) with a concomitant change in morphology was observed for M. smegmatis under carbon-deprived conditions. In addition, M. smegmatis assumed a coccoid morphology when ppGpp was ectopically produced by overexpressing Escherichia coli relA, even in an enriched medium. The Mycobacterium tuberculosis relA and spoT homologue, when induced in M. smegmatis, also resulted in the overproduction of ppGpp with a change in the bacterium's growth characteristics.

Stage-specific development of a novel adenosine transporter in Leishmania donovani amastigotes.

Leishmania donovani, like all other kinetoplastida, is a purine auxotroph. Comparative studies of adenosine transport in L. donovani amastigotes and promastigotes revealed that, unlike the promastigote stage, the amastigote possesses two distinct adenosine transporters (T(1) and T(2)) both with high affinities (K(m), 1.14+/-0.05 and 2. 09+/-0.13 microM, respectively). One of these transporters (T(1)) appears to be identical with the adenosine/pyrimidine nucleoside transporter of the promastigote reported earlier. The other transporter (T(2)) is specific for the amastigote stage and transports only purine nucleosides. The biological significance of this stage-specific development of the second adenosine transporter has been briefly discussed.

Elevated day 3 serum follicle stimulating hormone and/or estradiol may predict fetal aneuploidy.

OBJECTIVE: To determine whether baseline serum FSH and/or E2 concentrations can predict the risk for fetal chromosomal abnormalities. DESIGN: Case control study. SETTING: Reproductive technology program at a university hospital. PATIENT(S): Patients who underwent dilation and curettage (D + C), and whose products of conception were karyotyped. INTERVENTION(S): Patients underwent natural conception or controlled ovarian hyperstimulation followed by intrauterine insemination, in vitro fertilization and embryo transfer, gamete intrafallopian transfer, or zygote intrafallopian transfer. MAIN OUTCOME MEASURE(S): Baseline serum FSH and E2 concentrations and fetal karyotype. RESULT(S): Genetic evaluation of 78 D + C specimens revealed 34 normal and 44 abnormal fetal karyotypes. A significantly greater proportion of women with abnormal fetal karyotype had elevated baseline serum FSH (> or =15 mIU/mL [RIA] or 10 mIU/mL [Immulite]) and/or E2 > or = 50 pg/mL [Immulite]) compared with women of normal fetal karyotype. Among karyotypically abnormal abortuses, autosomal trisomy was the most common abnormality noted (79.5%), followed by mosaicism (6.8%), triploidy (6.8%), monosomy XO (4.5%), and balanced translocation (2.3%). CONCLUSION(S): Baseline serum FSH and/or E2 concentrations may be valuable as predictors of fetal aneuploidy.

Sisters of women with premature ovarian failure may not be ideal ovum donors.

OBJECTIVES: To determine whether the sisters of women with premature ovarian failure (POF) showed a response to gonadotropin stimulation comparable to that of anonymous ovum donors. DESIGN: Historical cohort study. SETTING: Records of 228 consecutive ovum recipients in an academic assisted reproductive technology program. PATIENT(S): Criteria for inclusion were oocyte recipients age < or = 40 years, FSH > 18 mIU/mL (conversion factor to SI unit, 1.00), and/or failure to respond appropriately to controlled ovarian hyperstimulation (COH). Seventy-nine recipients were classified on the basis of whether they received oocytes from anonymous donors (group I, n = 66) or sister donors (group II, n = 13). MAIN OUTCOME MEASURE(S): Controlled ovarian hyperstimulation response, pregnancy rates (PRs), and implantation rates. RESULT(S): The ages of the donors to groups I and II were comparable (31.1 +/- 16.7 versus 29.8 +/- 7.2 years), but those in group II exhibited a higher baseline FSH level (12.8 +/- 2.1 versus 8.6 +/- 5.8 mIU/mL). Group II versus I had a relative risk of 5.1 for cancellation (4 of 13 [30.8%] versus 4 of 66 [6.1%], respectively). In completed cycles of groups I and II, respectively, there was no difference in serum E2 on the day of hCG administration (2,356 +/- 826 versus 1,847 +/- 843 pg/mL; conversion factor to SI unit, 3,671), number of oocytes retrieved (25 +/- 14 versus 22 +/- 13), number of embryos transferred (4.4 +/- 2.1 versus 4.0 +/- 1.0), spontaneous abortion rate (22.7% versus 25.0%), PR (35.5% versus 36.4%), and implantation rate (16.2% versus 16.4%). CONCLUSION(S): There is an increased cancellation rate and, consequently, an overall trend toward decreased ovarian response to gonadotropin stimulation in the sisters of patients with POF. Despite these factors, the implantation rates and PRs of embryos derived from patients reaching retrieval were similar to those from anonymous donors. We recommend counseling women with POF that their sisters may not be ideal ovum donors.

Endometriosis is not detrimental to embryo implantation in oocyte recipients.

PURPOSE: Our purpose was to determine the effects of endometriosis on implantation and pregnancy rates in ovum recipients. METHODS: The medical records of 239 consecutive oocyte recipient patients who were treated between January 1, 1991, and June 30, 1995, were analyzed retrospectively. Recipients with endometriosis (group 1; n = 55) were compared to recipients without endometriosis (group II; n = 184). Patients in group I had active endometriotic disease confirmed by laparoscopy and were subdivided into mild (Stages I and II; n = 18) and moderate to severe (Stages III and IV; n = 37) endometriosis. RESULTS: No difference was found in recipient age, endometrial thickness, donor age, and embryos transferred. The pregnancy rates (28 versus 29%) and implantation rates (12 and 13%) were also comparable between group I and group II, as well as between patients with mild and patients with moderate to severe endometriosis. CONCLUSIONS: The presence of endometriosis in oocyte recipients does not lower implantation or pregnancy rates. We conclude that the adverse effect of endometriosis on reproductive outcome is not related to implantation but, in fact, is most likely an effect on oocyte or embryo quality.

The plasma-membrane Ca2+-ATPase of Leishmania donovani is an extrusion pump for Ca2+.

Controlled exposure of Leishmania donovani promastigotes to hypotonic shock results in the formation of deflagellated unsealed ghosts of original polarity that largely retain the pellicular microtubular structure associated with plasma membrane of the parasite. Gentle shearing followed by suspension of the purified membrane in appropriate isotonic buffer containing Mg2+ (4mM) results in the formation of sealed everted vesicles. The presence of Mg2+ (4 mM) appears to be essential for efficient sealing and also to prevent leakiness. ATP-dependent Ca2+ accumulation can be demonstrated in these vesicles Km values for Ca2+ and ATP were 125 nM and 0.8 mM respectively. The accumulated Ca2+ reaches a concentration of 1.1 mM. Ca2+ uptake is completely inhibited by vanadate (40 microM) and several thiol-modifying agents. Using 5,5'-dithiobis-(2-nitrobenzoic acid) as the modifying agent, an excellent correlation between loss of enzyme activity and transport capability and their parallel regeneration in the presence of 2 mM dithiothreitol was demonstrated. Using 2'.7-bis(carboxyethyl)-5(6)-carboxyfluorescein as the fluorescent pH probe, it was observed that Ca2+ entry into the vesicles is accompanied by an outward movement of H+ from the vesicles. Taken together, this paper establishes that the high-affinity transmembrane Ca2+-ATPase [Ghosh, Ray, Sarkar and Bhaduri (1990) J. Biol. Chem. 265, 11345-11351; Majumdar, Mukherjee, Ray and Bhaduri (1992) J. Biol. Chem. 267, 18440-18446] is an extrusion pump for Ca2+ in this human pathogen.

A randomized, placebo-controlled study on the effect of cyclic intermittent etidronate therapy on the bone mineral density changes associated with six months of gonadotropin-releasing hormone agonist treatment.

OBJECTIVE: Our purpose was to determine whether intermittent cyclic etidronate therapy blocks the decline in bone density associated with gonadotropin-releasing hormone agonist therapy. STUDY DESIGN: Thirty-one premenopausal subjects who needed treatment with leuprolide (Lupron) 3.75 mg monthly for 6 months were randomized to etidronate or placebo. Bone turnover was assessed by measurement of serum calcium, phosphorus, alkaline phosphatase, and fasting urinary calcium/creatinine ratios. Bone density was measured by dual energy x-ray absorptiometry. RESULTS: Gonadotropin-releasing hormone treatment produced a significant decrease (4% to 10%) in bone density at the anteroposterior and lateral spine in placebo-treated patients (11). No significant change was demonstrated in etidronate-treated patients (15). Significant increases in serum calcium, phosphorus, alkaline phosphatase, and urinary calcium/creatinine ratios were noted in the placebo group. No significant change in these parameters were evident in the etidronate group. CONCLUSION: Etidronate blocks bone mineral density changes associated with gonadotropin-releasing hormone agonist therapy and normalizes serum and urine indicators of bone turnover.