Osteosarcoma in Pediatric and Adult Populations: Are Adults Just Big Kids?

Malignant bone tumors are commonly classified as pediatric or adolescent malignancies, and clinical trials for these diseases have generally focused on these populations. Of primary bone cancers, osteosarcoma is among the most common. Osteosarcoma has a bimodal age distribution, with the first peak occurring in patients from 10 to 14 years old, and the second peak occurring in patients older than 65, with about 25% of cases occurring in adults between 20 and 59 years old. Notably, adult osteosarcoma patients have worse outcomes than their pediatric counterparts. It remains unclear whether age itself is a poor prognostic factor, or if inherent differences in tumor biology exist between age groups. Despite these unknowns, current treatment strategies for adults are largely extrapolated from pediatric studies since the majority of clinical trials for osteosarcoma treatments are based on younger patient populations. In light of the different prognoses observed in pediatric and adult osteosarcoma, we summarize the current understanding of the molecular etiology of osteosarcoma and how it may differ between age groups, hypothesizing why adult patients have worse outcomes compared to children.

Graphene as a rational interface for enhanced adsorption of microcystin-LR from water

Cyanotoxins such as microcystin-LR (MC-LR) represent a global environmental threat to ecosystems and drinking water supplies. The study investigated the direct use of graphene as a rational interface for removal of MC-LR via interactions with the aromatic ring of the ADDA1 chain of MC-LR and the sp2 hybridized carbon network of graphene. Intra-particle diffusion model fit indicated the high mesoporosity of graphene provided significant enhancements to both adsorption capacities and kinetics when benchmarked against microporous granular activated carbon (GAC). Graphene showed superior MC-LR adsorption capacity of 75.4 mg/g (Freundlich model) compared to 0.982 mg/g (Langmuir model) for GAC. Sorption kinetic studies showed graphene adsorbs 99% of MC-LR in 30 min, compared to zero removal for GAC after 24 hr using the same MC-LR concentration. Density functional theory (DFT), calculations showed that postulated π-based interactions align well with the NMR-based experimental work used to probe primary interactions between graphene and MC-LR adduct. This study proved that π-interactions between the aromatic ring on MC-LR and graphene sp2 orbitals are a dominant interaction. With rapid kinetics and adsorption capacities much higher than GAC, it is anticipated that graphene will offer a novel molecular approach for removal of toxins and emerging contaminants with aromatic systems.

Graphene-Mediated removal of Microcystin-LR in chitosan/graphene composites for treatment of harmful algal blooms

Water quality can be severely impacted by algal blooms alone, yet cyanotoxins, such as microcystin (MC), are potent underlying hazards produced by various species of cyanobacteria. Currently there is a need for environmentally compatible and economically viable media to address large scale application for HAB impacted waters. This study evaluated the interactions of chitosan/graphene (CSG) composites with three different species of cyanobacteria: Anabaena sp, Synechocystis sp, and Microcystis aeruginosa for both removal of algal optical density and toxins. Although results suggest that CSG has an algae dependent removal of density with a range of 40-90% removal, graphene/CSG is highly effective at MC toxin removal, removing >94% of MC-LR produced by Microcystis aeruginosa. Characterization by SEM and XRD revealed that 750 m²/g surface area graphene, imparts graphene morphology and functionality into the chitosan matrix surface, potentially enabling π-π interactions between graphene and the aromatic ring of microcystin. This proposed π-π removal mechanism of microcystin via the CSG chitosan biopolymer substrate offers a promising sustainable and selective media suitable for deployable treatment of HAB impacted waters.

Outcomes for circulatory death and brainstem death pancreas transplantation with or without use of normothermic regional perfusion

Simultaneous pancreas and kidney transplantation is the optimum treatment for patients with type 1 diabetes and renal failure, providing survival benefit over deceased donor kidney transplant alone. Here the authors demonstrate that utilization of donation after circulatory death pancreases is a safe approach to expanding the donor pool with equivalent results to donation after brainstem death transplantation. They also demonstrate that pancreas transplantation after normothermic regional perfusion is feasible, but it will require ongoing prospective study to ensure that the benefits seen for liver transplantation do not come at the expense of pancreas transplant outcomes.

Clinical Care Guideline for Improving Pediatric Acute Musculoskeletal Infection Outcomes

BACKGROUND

Acute pediatric musculoskeletal infections are common, leading to significant use of resources and antimicrobial exposure. In order to decrease variability and improve the quality of care, Children's Hospital Colorado implemented a clinical care guideline (CCG) for these infections. The purpose of this study is to evaluate clinical and resource outcomes PRE and POST this CCG.

METHODS

Retrospective chart review evaluated patients admitted to a large pediatric quaternary referral center (CHCO) diagnosed with acute osteomyelitis, septic arthritis, pyomyositis, and/or musculoskeletal abscess prior to and after guideline implementation. Primary outcomes included length of stay and overall antibiotic use, with additional secondary clinical, process, and therapeutic outcomes examined.

RESULTS

82 patients were identified in both the pre-CCG and post-CCG cohorts. There was a reduction in the median of all primary outcomes, including length of stay (0.6 median days decrease, P = .04), length of IV antibiotic therapy (4.9 median days decrease, P < .0001), and days of IV antibiotic therapy (6.4 median days decrease, P = .0004). Our median length of stay post-CCG was 4.9 days, the shortest reported length of stay for pediatric acute musculoskeletal infections to date. Additionally, there was a 24.5 hour reduction in median length of fever (P = .02), faster CRP normalization (P < .0001), 50% decrease in the number of related readmissions (P = .02), 34% decrease in central venous catheters placed (P < .0001), decreased time to first culture (P = .02), and 79% pathogen identification post-CCG (P = .056).

CONCLUSIONS

Implementation of a CCG for acute musculoskeletal infections improves patient, process and resource outcomes.

Pathological pelvic fracture following long-term bisphosphonate use in a 63-year-old woman

A 63-year-old woman presented with a low energy pelvic fracture, which showed no signs of healing. Initial fractures were to the right hemipelvis, later followed by a right fractured neck of femur. We present a complicated patient journey, management dilemmas and highlight the growing concern with long-term bisphosphonate treatment.

A novel ex vivo culture model for inflammatory bone destruction

Pathological alterations in the balance of bone metabolism are central to the progression of inflammatory bone diseases such as periodontal disease. We have developed and characterized a novel ex vivo murine mandible model of inflammatory bone destruction. Slices of mandible were cultured for 14 days in the presence or absence of P. gingivalis lipopolysaccharide (LPS) or pro-inflammatory cytokines. Following culture, cell viability and tissue histomorphometry were assessed with quantification of matrix proteins, resident osteoclasts, ligament cells, monocytes, macrophages, and neutrophils. In the absence of inflammatory factors, culture viability, osteoclasts, and matrix components were maintained. LPS or TNFα stimulation demonstrated an increase in cellular proliferation, monocyte cells, osteoclast differentiation, and matrix degradation. Pathophysiological bone metabolism can be induced via exposure to LPS and direct influence of TNFα within the model despite the absence of systemic circulation, providing a model for inflammatory bone destruction and investigation of the effects of novel therapeutics.

An in vitro study of alginate oligomer therapies on oral biofilms

OBJECTIVES

The in vitro effect of a novel, oligosaccharide nanomedicine OligoG against oral pathogen-related biofilms, both alone and in the presence of the conventional anti-bacterial agent triclosan, was evaluated.

METHODS

The effect of OligoG±triclosan was assessed against established Streptococcus mutans and Porphyromonas gingivalis biofilms by bacterial counts and image analysis using LIVE/DEAD(®) staining and atomic force microscopy (AFM). The effect of triclosan and OligoG surface pre-treatments on bacterial attachment to titanium and polymethylmethacrylate was also studied.

RESULTS

OligoG potentiated the antimicrobial effect of triclosan, particularly when used in combination at 0.3% against S. mutans grown in artificial saliva. OligoG was less effective against established P. gingivalis biofilms. However, attachment of P. gingivalis, to titanium in particular, was significantly reduced after surface pre-treatment with OligoG and triclosan at 0.01% when compared to controls. Light microscopy and AFM showed that OligoG was biocidal to P. gingivalis, but not S. mutans.

CONCLUSIONS

OligoG and triclosan when used in combination produced an enhanced antimicrobial effect against two important oral pathogens and reduced bacterial attachment to dental materials such as titanium, even at reduced triclosan concentrations. Whilst the use of triclosan against oral bacteria has been widely documented, its synergistic use with OligoG described here, has not previously been reported. The use of lower concentrations of triclosan, if used in combination therapy with OligoG, could have environmental benefits.

CLINICAL IMPORTANCE

The potentiation of antimicrobial agents by naturally occurring oligomers such as OligoG may represent a novel, safe adjunct to conventional oral hygiene and periodontal therapy. The ability of OligoG to inhibit the growth and impair bacterial adherence highlights its potential in the management of peri-implantitis.

Subjective memory complaints and awareness of memory functioning in mild cognitive impairment: a systematic review

OBJECTIVES

Subjective memory complaint (SMC) is central to the diagnosis of mild cognitive impairment (MCI). People with MCI are at a higher risk of progressing to dementia, and research on SMC is contradictory in terms of the accuracy of SMC and its predictive role for future dementia. One possible reason for these contradictory findings is that the level of awareness of memory function may vary among people with MCI. This review examines whether the level of awareness of memory functioning varies amongst people classified as having MCI and whether there is support for the suggestion that the level of awareness in MCI predicts future progression to dementia.

METHOD

Sixteen studies were identified which evaluate the awareness level in people classified as having MCI in either a clinical or research setting. In addition to the outcome of each study, the conceptualization of awareness, 'object' of awareness and methodology were also considered.

RESULTS

There is evidence to show that the level of awareness in MCI does vary, and this may have implications for future progression to dementia.

CONCLUSIONS

Given the increased risk of progression to dementia for those identified as having MCI, the role of awareness should be explored further with due consideration given to the conceptualization of awareness and the methodology employed. The finding of variability in awareness has implications for the use of SMC in the diagnostic criteria for MCI.

Supratentorial epidural hematoma of traumatic etiology in infants

INTRODUCTION AND BACKGROUND

Traumatic epidural hematoma (EDH) represents a rare head injury complication in infants. Its diagnosis can be quite challenging because its clinical presentation is usually subtle and nonspecific. In our current communication, we present our data regarding the presentation of infants with EDH, their management, and their long-term outcome.

MATERIALS AND METHODS

In a retrospective study, the hospital and outpatient clinic charts and imaging studies (head CT and skull X-rays) of 31 infants with pure, supratentorial EDH of traumatic origin were meticulously reviewed. Children Coma Scale score and Trauma Infant Neurologic Score (TINS) were also reviewed. The most common presenting symptom was irritability, which occurred in 18/31 (58.1%) of our patients. Pallor (in 30/31 patients) and cephalhematoma (in 21/31 patients) were the most commonly occurring clinical signs upon admission; both signs represent signs of significant clinical importance. Surgical evacuation via a craniotomy was required in 24/31 of our patients, while 7/31 patients were managed conservatively. The mortality rate in our series was 6.5% (2/31 patients), and our long-term morbidity rate was 3.2% (1/31 patients).

CONCLUSIONS

EDH in infants represents a life-threatening complication of head injury, which requires early identification and prompt surgical or conservative management depending on the patient's clinical condition, size of EDH, and presence of midline structure shift on head CT scan. Mortality and long-term morbidity are low with early diagnosis and prompt treatment.

A Case of 46,X,der(X)t(X;X)(q22.1;p11) Xq22.1→Xqter in a 12-Year-Old Girl with Premature Ovarian Failure

Premature ovarian failure due to Xp duplication and Xq deletion has been reported in four patients, the youngest of whom was 18 years old. The diagnosis has been made with new techniques for genetic analysis, such as comparative genomic hybridization and fluorescence in situ hybridization. We report the youngest case (a 12-year-old who presented with irregular menses), of premature ovarian failure due to Xp duplication and Xq deletion and the first with 46,X,der(X)t(X;X)(q22.1;p11). The diagnosis was made using C-banding and fluorescent in situ hybridization with locus-specific probes. This case highlights the need to use advanced genetic strategies to determine karyotypic and phenotypic abnormalities.

A prospective randomized comparison of extensive prostate biopsy to standard biopsy with assessment of diagnostic yield, biopsy pain and morbidity

In a prospective randomized study, we compare standard prostate biopsy to extensive biopsy utilizing intravenous conscious sedation (IVCS). Initial biopsy patients (n=197) were randomized to either standard biopsy using intrarectal lidocaine gel (6-12 biopsies, mean 10.1) or extensive biopsy (24 biopsies) using IVCS. Cancer detection and urinary symptoms were no different between groups. However, biopsy pain was rated significantly lower and satisfaction significantly higher in the extensive biopsy group. Temporary urinary retention occurred in 4% of the extensive biopsy group. Extended biopsy with 24 samples does not improve cancer detection compared to standard biopsy when 10 cores are obtained. Extensive biopsy is very well tolerated and associated with less pain and more satisfaction than standard biopsy.

Electron temperature of ultracold plasmas

We study the evolution of ultracold plasmas by measuring the electron temperature. Shortly after plasma formation, competition between heating and cooling mechanisms drives the electron temperature to a value within a narrow range regardless of the initial energy imparted to the electrons. In agreement with theory predictions, plasmas exhibit values of the Coulomb coupling parameter Gamma less than 1.

Novel roles of neuropeptide processing enzymes: EC3.4.24.15 in the neurome

Neuropeptide processing metalloenzymes, such as angiotensin converting enzyme, neprilysin, endothelin converting enzyme, neurolysin, and EC3.4.24.15 (EP24.15), are central to the formation and degradation of bioactive peptides. We present EP24.15 as a paradigm for novel functions ascribed to these enzymes in the neurome. Although the neurome typically encompasses proteomes of the brain and central nervous system, exciting new roles of these neuropeptidases have been demonstrated in other organ systems. We discuss the involvement of EP24.15 with clinical sequelae involving the use of gonadotropin-releasing hormone (GnRH; LHRH) analogs that act as enzyme inhibitors, in vascular physiology (blood pressure regulation), and in the hematologic system (immune surveillance). Hemodynamic forces, such as cyclic strain and shear stress, on vascular cells, induce an increase in EP24.15 transcription, suggesting that neuropeptidase-mediated hydrolysis of pressor/depressor peptides is likely regulated by changes in hemodynamic force and blood pressure. Lastly, EP24.15 regulates surface expression of major histocompatibility complex Class I proteins in vivo, suggesting that EP24.15 may play an important role in maintenance of immune privilege in sites of increased endogenous expression. In these extraneural systems, regulation of both neuropeptide and other peptide substrates by neuropeptidases indicates that the influence of these enzymes may be more global than was anticipated previously, and suggests that their attributed role as neuropeptidases underestimates their physiologic actions in the neural system.

Long-term effects of the mammary carcinogen 7,12-dimethylbenz(a) anthracene on hypothalamic gonadotropin-releasing hormone and its pituitary receptor gene expression, during the promotion stage, in female Sprague-Dawley rats

A single intragastric administration of 7,12-dimethylbenz(a)anthracene (DMBA) has been shown to induce mammary tumors in young cycling female Sprague-Dawley rats. The appearance of these tumors is preceded by a series of neuroendocrine disturbances, including attenuation of the preovulatory luteinizing hormone (LH) surge and amplification of the preovulatory 17beta-estradiol surge, and gonadotropin-releasing hormone (GnRH) released in vitro. In this study, we examined the hypothesis that DMBA administration decreases levels of GnRH mRNA in the preoptic area-anterior hypothalamus (POA-AH) and GnRH receptor (GnRH Rc) mRNA and protein in the anterior pituitary gland. Sprague-Dawley rats, 55-60 days of age with regular estrous cycles, received a single dose of 15 mg DMBA in 1 ml sesame oil delivered by intragastric intubation. A first series of experiments was performed for the measurement of hypothalamic GnRH mRNA and pituitary GnRH Rc mRNA levels. A second series of experiments was performed for the measurement of pituitary GnRH receptor. In both experiments, animals were sacrificed by decapitation at 11.00, 16.00, 18.00 and 20.00 h on each day of the 7th or 8th estrous cycle (28-32 days) after treatment. GnRH and GnRH receptor mRNAs were quantified using solution hybridization-RNase protection assay. The GnRH Rc was quantified using the 125I-D-Ala6-N-Met-Leu6-des-Gly10-ethylamide GnRH. DMBA-treatment produced no significant effect on the overall mean values of GnRH mRNA. GnRH mRNA levels in control rats rose significantly between 16.00 and 20.00 h on proestrus and between 18.00 and 20.00 h on diestrus I. DMBA-treated rats had a surge in GnRH mRNA levels at 18.00 h on proestrus, and showed additional surges at 18.00h on diestrus II and estrus. GnRH receptor mRNA content in the anterior pituitary gland surged at 16.00h on certain days of the cycle in both groups of rats. In control rats, only the surge on diestrus II proved significant, whereas DMBA-treated rats exhibited significant surges on diestrus I, diestrus II and proestrus. GnRH receptor mRNA values were significantly lower on both days of diestrus in DMBA-treated rats compared with controls. GnRH Rc peptide content, like GnRH receptor in RNA surged at 16.00h in both groups with the exception of a marked fall on proestrus day for DMBA treated rats. A reduction in the amplitude of the surge was also seen on the day of estrous and to a lesser extend on the day of diestrus DII in DMBA treated animal. Overall, there was a disruption of the GnRH Rc pattern which culminate on the day of proestrus in DMBA-treated animals. Interestingly, the daily rise between 11.00 and 16.00h which is the more pronounced on the day of proestrus in control animals, was completely blunted in DMBA-treated rats. Overall, the results are consistent with the hypothesis that the carcinogen attenuates, directly or indirectly, preovulatory biosynthesis of the GnRH receptor and LH release. Obviously, the changes in GnRH might occur simultaneously, independently from mammary tumorigenesis, but may play a role, in association with others DMBA-induced neuroendocrine disorders, in the promotion stage of mammary tumors in the Sprague-Dawley female rat.

Unexpected effects of FERM domain mutations on catalytic activity of Jak3: structural implication for Janus kinases

Janus kinases comprise carboxyterminal kinase, pseudokinase, SH2-like, and N-terminal FERM domains. We identified three patient-derived mutations in the FERM domain of Jak3 and investigated the functional consequences of these mutations. These mutations inhibited receptor binding and also abrogated kinase activity, suggesting interactions between the FERM and kinase domains. In fact, the domains were found to physically associate, and coexpression of the FERM domain enhanced activity of the isolated kinase domain. Conversely, staurosporine, which alters kinase domain structure, disrupted receptor binding, even though the catalytic activity of Jak3 is dispensable for receptor binding. Thus, the Jak FERM domain appears to have two critical functions: receptor interaction and maintenance of kinase integrity.

Relationship between obesity and race in predicting adverse pathologic variables in patients undergoing radical prostatectomy

OBJECTIVES

To determine whether obesity is associated with more advanced prostate cancer (PCa) in radical prostatectomy patients and to explore the ethnic variability in body mass index (BMI) as a potential explanation for racial differences in PCa risk.

METHODS

A multi-institutional retrospective analysis of the clinical and pathologic parameters was performed on data from 860 patients with PCa undergoing radical prostatectomy between 1992 and 1998. Patient height and weight was used to calculate the BMI, which categorized patients into obese (BMI 30 kg/m(2) or greater), overweight (BMI 25 to 30 kg/m(2)), and normal (BMI 25 kg/m(2) or less) groups. Age, serum prostate-specific antigen level, pathologic stage, and Gleason score for each group were compared. The distribution of the BMI in each of four ethnic groups was also determined.

RESULTS

Of 860 patients, 171 (20%) were obese, 425 (49%) overweight, and 264 (31%) normal. The obese patients presented at a younger mean age (62 years, P = 0.001), had higher mean Gleason scores (6.7, P = 0.002), had a higher likelihood of Gleason score 7 or greater cancer (71%, P = 0.003), and had a lower chance of organ-confined cancer (46%, P = 0.050). The BMI was highest in blacks, followed by whites and Asians, and blacks had significantly higher grade cancers (P = 0.045). In multiple logistic regression analysis of the BMI and race, only BMI remained an independent predictor of Gleason grade.

CONCLUSIONS

Obese patients with PCa present for radical prostatectomy at a younger age with higher grade and more pathologically advanced cancers. Blacks have higher grade cancers than other ethnic groups and, at the same time, have significantly higher BMIs. These findings suggest that obesity may in part account for the racial variability in PCa risk.

Presence of luteinizing hormone-releasing hormone fragments in the rhesus monkey forebrain

Previously, we have shown that two types of luteinizing hormone-releasing hormone (LHRH) -like neurons, "early" and "late" cells, were discernible in the forebrain of rhesus monkey fetuses by using antiserum GF-6, which cross-reacts with several forms of LHRH. The "late" cells that arose from the olfactory placode of monkey fetuses at embryonic days (E) 32-E36, are bona fide LHRH neurons. The "early" cells were found in the forebrain at E32-E34 and settled in the extrahypothalamic area. The molecular form of LHRH in "early" cells differs from "late" cells, because "early" cells were not immunopositive with any specific antisera against known forms of LHRH. In this study, we investigated the molecular form of LHRH in the "early" cells in the nasal regions and brains of 13 monkey fetuses at E35 to E78. In situ hybridization studies suggested that both "early" and "late" LHRH cells expressed mammalian LHRH mRNA. Furthermore, "early" cells predominantly contain LHRH1-5-like peptide and its cleavage enzyme, metalloendopeptidase E.C.3.4.24.15 (EP24.15), which cleaves LHRH at the Tyr5-Gly6 position. This conclusion was based on immunocytochemical labeling with various antisera, including those against LHRH1-5, LHRH4-10, or EP24.15, and on preabsorption tests. Therefore, in primates, a group of neurons containing mammalian LHRH mRNA arises at an early embryonic stage before the migration of bona fide LHRH neurons, and is ultimately distributed in the extrahypothalamic region. These extrahypothalamic neurons contain LHRH fragments, rather than fully mature mammalian LHRH. The origin and function of these neurons remain to be determined.

Australia's campaign to eradicate bovine tuberculosis: the battle for freedom and beyond

In 1970, voluntary State-based TB control programs in Australia were replaced by a coordinated national campaign to eliminate both brucellosis and tuberculosis from the cattle population. The campaign was funded and managed under tripartite agreement by State/Territory and Commonwealth governments and Industry. The tuberculosis component of the campaign relied on test and slaughter with surveillance for the disease in abattoirs and trace-back to property of origin an essential component. Because of the moderate sensitivity of the skin test ( approximately 70%), testing was repeated at prescribed intervals over a number of years. In the more hostile environment of northern Australia, novel strategies were developed to maximize musters and remove 'at risk' animals. Australia is fortunate it did not have a feral host for M. bovis (apart from buffalo, which were included in the campaign) to complicate eradication. A national granuloma submission program was implemented in 1992 to increase the intensity of abattoir monitoring. Selective or total depopulation was used in some herds to achieve the requirements of the national Standard Definitions and Rules of the Campaign and achieve the status of 'TB Free Area' in December 1997. Monitoring for tuberculosis has continued under the 5-year Tuberculosis Freedom Assurance Program and measures to further reduce the risk of new cases have been implemented.

Repeat biopsy strategy in patients with atypical small acinar proliferation or high grade prostatic intraepithelial neoplasia on initial prostate needle biopsy

PURPOSE

Isolated high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation on prostate biopsy increases the risk of identifying cancer on repeat biopsy. We report the results of repeat prostate biopsy for high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation, and propose an optimal repeat biopsy strategy.

MATERIALS AND METHODS

Of 1,391 men who underwent standard systematic sextant biopsy of the prostate 137 (9.8%) had isolated high grade prostatic intraepithelial neoplasia or atypical small acinar proliferation, including 100 who underwent repeat prostate biopsy within 12 months of the initial biopsy.

RESULTS

Adenocarcinoma was detected in 47 of the 100 patients who underwent repeat biopsy. The initial biopsy site of high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation matched the sextant location of cancer on repeat biopsy in 22 cases (47%). Repeat biopsy directed only to the high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation site on initial biopsy would have missed 53% of cancer cases. In 12 of the 47 men (26%) cancer was limited to the side of the prostate contralateral to the side of high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation. Of the 31 patients with cancer in whom the transition zone was sampled cancer was limited to the transition zone in 4 (13%) and evident at other biopsy sites in 13 (42%). The only significant predictor of positive repeat biopsy was mean prostate specific antigen velocity plus or minus standard error (1.37 +/- 1.4 versus 0.52 +/- 0.8 ng./ml. per year, p <0.001).

CONCLUSIONS

Patients with isolated high grade prostatic intraepithelial neoplasia and/or atypical small acinar proliferation on prostate biopsy are at 47% risk for cancer on repeat biopsy. The optimal repeat biopsy strategy in this setting should include bilateral biopsies of the standard sextant locations. We also strongly recommend that transition zone sampling should be considered.

Dynamics of collapsing and exploding Bose-Einstein condensates

When atoms in a gas are cooled to extremely low temperatures, they will-under the appropriate conditions-condense into a single quantum-mechanical state known as a Bose-Einstein condensate. In such systems, quantum-mechanical behaviour is evident on a macroscopic scale. Here we explore the dynamics of how a Bose-Einstein condensate collapses and subsequently explodes when the balance of forces governing its size and shape is suddenly altered. A condensate's equilibrium size and shape is strongly affected by the interatomic interactions. Our ability to induce a collapse by switching the interactions from repulsive to attractive by tuning an externally applied magnetic field yields detailed information on the violent collapse process. We observe anisotropic atom bursts that explode from the condensate, atoms leaving the condensate in undetected forms, spikes appearing in the condensate wavefunction and oscillating remnant condensates that survive the collapse. All these processes have curious dependences on time, on the strength of the interaction and on the number of condensate atoms. Although the system would seem to be simple and well characterized, our measurements reveal many phenomena that challenge theoretical models.

Controlled collapse of a Bose-Einstein condensate

The point of instability of a Bose-Einstein condensate (BEC) due to attractive interactions was studied. Stable 85Rb BECs were created and then caused to collapse by slowly changing the atom-atom interaction from repulsive to attractive using a Feshbach resonance. At a critical value, an abrupt transition was observed in which atoms were ejected from the condensate. By measuring the onset of this transition as a function of number and attractive interaction strength, we determined the stability condition to be N(absolute value of a) / a(ho) = 0.459+/-0.012+/-0.054, slightly lower than the predicted value of 0.574.

The neuropeptide processing enzyme EC 3.4.24.15 is modulated by protein kinase A phosphorylation

The metalloendopeptidase EC (EP24.15) is a neuropeptide-metabolizing enzyme expressed predominantly in brain, pituitary, and testis, and is implicated in several physiological processes and diseases. Multiple putative phosphorylation sites in the primary sequence led us to investigate whether phosphorylation effects the specificity and/or the kinetics of substrate cleavage. Only protein kinase A (PKA) treatment resulted in serine phosphorylation with a stoichiometry of 1.11 +/- 0.12 mol of phosphate/mol of recombinant rat EP24.15. Mutation analysis of each putative PKA site, in vitro phosphorylation, and phosphopeptide mapping indicated serine 644 as the phosphorylation site. Phosphorylation effects on catalytic activity were assessed using physiological (GnRH, GnRH(1-9), bradykinin, and neurotensin) and fluorimetric (MCA-PLGPDL-Dnp and orthoaminobenzoyl-GGFLRRV-Dnp-edn) substrates. The most dramatic change upon PKA phosphorylation was a substrate-specific, 7-fold increase in both K(m) and k(cat) for GnRH. In both rat PC12 and mouse AtT-20 cells, EP24.15 was serine-phosphorylated, and EP24.15 phosphate incorporation was enhanced by forskolin treatment, and attenuated by H89, consistent with PKA-mediated phosphorylation. Cloning of the full-length mouse EP24.15 cDNA revealed 96.7% amino acid identity to the rat sequence, and conservation at serine 644, consistent with its putative functional role. Therefore, PKA phosphorylation is suggested to play a regulatory role in EP24.15 enzyme activity.

Estrogen and tamoxifen differentially regulate beta-endorphin and cFos expression and neuronal colocalization in the arcuate nucleus of the rat

Estrogen regulates hypothalamic gene expression, synthesis and release of the endogenous opioid peptide beta-endorphin (betaEND), although a consensus estrogen response element sequence has not been identified in the rat proopiomelanocortin (POMC) gene. POMC gene expression is also regulated by the activation of AP-1 promoter elements, which are known to be estrogen sensitive. The present studies examine whether estrogen modulates the hypothalamic POMC system through a non-classical mechanism involving AP-1 binding proteins such as cFos. Immunohistochemical double-labeling for betaEND and cFos was used and immunoreactive (-ir) populations were quantified in the arcuate nucleus and periarcuate area across time using unbiased stereological methods. Ovariectomized rats were injected with 50 microg estradiol (E2), 500 microg tamoxifen citrate (TAM) or both (E2+TAM) and were perfused 1, 2, 4 or 48 h later. E2 rapidly increased numbers of cFos-ir, betaEND-ir and doubly-labeled cells after 4 h, and the number of betaEND-ir cells remained high 48 h later, suggesting that the stimulatory effects of cFos on POMC in the hypothalamus persist after the cFos signal decays. Treatment with TAM alone did not affect the numbers of immunoreactive cells, although E2+TAM blocked the E2-mediated induction in all immunoreactive populations. Similar effects were seen at the transcriptional level. E2 increased hypothalamic POMC mRNA after 4 h, while TAM treatment or coadministration of E2+TAM did not significantly change the levels of POMC mRNA. Cellular colocalization of betaEND-ir and cFos-ir supports a possible intracellular co-regulation of these peptides by an estrogen-dependent mechanism within a subset of hypothalamic neurons. It does not, however, appear that E2 acts directly through an AP-1 site within the POMC gene.

Lack of efficacy of finasteride in postmenopausal women with androgenetic alopecia

BACKGROUND

Finasteride, an inhibitor of type 2 5alpha-reductase, decreases serum and scalp dihydrotestosterone (DHT) by inhibiting conversion of testosterone to DHT and has been shown to be effective in men with androgenetic alopecia (AGA). The effects of finasteride in women with AGA have not been evaluated.

OBJECTIVE

The purpose of this study was to evaluate the efficacy of finasteride in postmenopausal women with AGA.

METHODS

In this 1-year, double-blind, placebo-controlled, randomized, multicenter trial, 137 postmenopausal women (41-60 years of age) with AGA received finasteride 1 mg/day or placebo. Efficacy was evaluated by scalp hair counts, patient and investigator assessments, assessment of global photographs by a blinded expert panel, and histologic analysis of scalp biopsy specimens.

RESULTS

After 1 year of therapy, there was no significant difference in the change in hair count between the finasteride and placebo groups. Both treatment groups had significant decreases in hair count in the frontal/parietal (anterior/mid) scalp during the 1-year study period. Similarly, patient, investigator, and photographic assessments as well as scalp biopsy analysis did not demonstrate any improvement in slowing hair thinning, increasing hair growth, or improving the appearance of the hair in finasteride-treated subjects compared with the placebo group. Finasteride was generally well tolerated.

CONCLUSION

In postmenopausal women with AGA, finasteride 1 mg/day taken for 12 months did not not increase hair growth or slow the progression of hair thinning.

Stable 85Rb bose-einstein condensates with widely tunable interactions

Bose-Einstein condensation has been achieved in a magnetically trapped sample of 85Rb atoms. Long-lived condensates of up to 10(4) atoms have been produced by using a magnetic-field-induced Feshbach resonance to reverse the sign of the scattering length. This system provides new opportunities for the study of condensate physics. The variation of the scattering length near the resonance has been used to magnetically tune the condensate self-interaction energy over a wide range, extending from strong repulsive to large attractive interactions. When the interactions were switched from repulsive to attractive, the condensate shrank to below our resolution limit, and after approximately 5 ms emitted a burst of high-energy atoms.

Magnetic field dependence of ultracold inelastic collisions near a feshbach resonance

Inelastic collision rates for ultracold 85Rb atoms in the F = 2, m(f) = -2 state have been measured as a function of magnetic field. At 250 gauss (G), the two- and three-body loss rates were measured to be K2 = (1.87+/-0.95+/-0.19)x10(-14) cm(3)/s and K3 = (4.24(+0. 70)(-0.29)+/-0.85)x10(-25) cm(6)/s, respectively. As the magnetic field is decreased from 250 G towards a Feshbach resonance at 155 G, the inelastic rates decrease to a minimum and then increase dramatically, peaking at the Feshbach resonance. Both two- and three-body losses are important, and individual contributions have been compared with theory.

Risk factors for vesicourethral anastomotic stricture after radical prostatectomy

OBJECTIVES

Preoperative comorbidities associated with microvascular disease may contribute to the development of bladder neck contracture (BNC) by alteration of anastomotic healing. We investigated potential risk factors for development of BNC after radical prostatectomy (RP) and reviewed management of this complication.

METHODS

A retrospective review of 467 consecutive patients (mean age 63.2 years) undergoing RP between 1991 and 1999 was performed. In all cases, the bladder neck was tailored to 20 to 22F in a racket handle fashion. After mucosal eversion of the reconstructed bladder neck, a mucosa-to-mucosa vesicourethral anastomosis was created over an 18 to 22F catheter using 4 to 6 anastomotic sutures. The relationship between comorbidities identified preoperatively by patient interview and medical record review (coronary artery disease [CAD], diabetes mellitus [DM], hypertension [HTN], cerebral vascular accident, chronic obstructive pulmonary disease, and smoking history) and the incidence of BNC was determined. Risk factors including prior transurethral prostatectomy (TURP), estimated blood loss (EBL), and operative time (OR time) were also evaluated. Factors were evaluated for their ability to predict BNC using both univariate and multivariate analysis. Treatment results for BNC were also assessed.

RESULTS

A total of 52 (11.1%) patients developed BNC. Current cigarette smoking resulted in a significantly higher (26%) rate of BNC (P <0.001). The BNC rate was also increased in patients with CAD (26%, P <0.001), HTN (19%, P = 0.015), and DM (21%, P = 0.030). Average OR time was longer (271 versus 249 minutes, P = 0.025) and EBL was greater (1639 versus 1092 mL, P <0.001) in patients developing a BNC. In multivariate analysis, current cigarette smoking was the strongest predictor of BNC and independent of other factors (P <0.001). BNC was not related to prior TURP, type of anastomotic suture used, size of catheter, or duration of catheterization. Patients were treated with transurethral dilation (73%) or transurethral incision (27%) and 58% responded to the initial treatment. No patient became incontinent as a result of the treatment for BNC.Conclusions. Several comorbidities associated with microvascular disease are significant risk factors for development of BNC after RP. Current cigarette smoking in particular is a strong predictor. Transurethral dilation and transurethral incision are equally effective as initial treatment of BNC.

A national study of pressure ulcer prevalence and incidence in acute care hospitals

OBJECTIVE

This study sought to establish national benchmarks for pressure ulcer prevalence and incidence among acute care health organizations served by Novation LLC.

SETTING AND SUBJECTS

One hundred sixteen acute care facilities from 34 states participated; the sample consisted of 17,560 patients in hospital-based medical-surgical or intensive care units.

INSTRUMENTS

Standardized education kits were provided to each participating site. The kits included an educational video about pressure ulcer staging, a post-test and answer key, and assessment form for patient data collection.

METHODS

Pressure ulcer prevalence was measured during a predetermined 24-hour period at each facility. Incidence was measured over the average length of stay determined for each participating facility. Subjects were assessed by teams consisting of a registered nurse and one other health care professional (e.g. licensed practical nurse, physical therapist). Demographic, wound, and other data were collected for these patients. Data collection forms were audited and submitted to a central site for database entry, analysis, and generation of reports.

RESULTS

The average length of stay for the participating facilities was 5 days. Pressure ulcers developed in 7% of the subjects (n = 383); 90% were stage I or II pressure ulcers, and 73% occurred in patients older than 65 years. The most sites based on both prevalence and incidence measurements were the sacrum and coccyx at 26% and 31%, respectively.

CONCLUSIONS

Prevalence and incidence studies must be routinely conducted to clearly identify the extent of the pressure ulcer problem to provide guidance for efficient and effective corrective action.

Female mice heterozygous for IKK gamma/NEMO deficiencies develop a dermatopathy similar to the human X-linked disorder incontinentia pigmenti

IKK gamma/NEMO is the essential regulatory subunit of the I kappa B kinase (IKK), encoded by an X-linked gene in mice and humans. It is required for NF-kappa B activation and resistance to TNF-induced apoptosis. Female mice heterozygous for Ikk gamma/Nemo deficiency develop a unique dermatopathy characterized by keratinocyte hyperproliferation, skin inflammation, hyperkeratosis, and increased apoptosis. Although Ikk gamma+/- females eventually recover, Ikk gamma- males die in utero. These symptoms and inheritance pattern are very similar to those of incontinentia pigmenti (IP), a human genodermatosis, synthenic with the IKK gamma/NEMO locus. Indeed, biopsies and cells from IP patients exhibit defective IKK gamma/NEMO expression but normal expression of IKK catalytic subunits. This unique self-limiting disease, the first to be genetically linked to the IKK signaling pathway, is dependent on X-chromosome inactivation. We propose that the IKK gamma/NEMO-deficient cells trigger an inflammatory reaction that eventually leads to their death.

Effect of N-methyl-D,L-aspartate (NMA) on gonadotropin-releasing hormone (GnRH) gene expression in male mice

The glutamate analog N-methyl-D,L-aspartate (NMA) affects the regulation of GnRH and LH release in mammals. Several laboratories have reported a rapid and transient increase in GnRH mRNA levels of male rats after NMA injection. Studies employing the simultaneous measurements of nuclear GnRH primary transcript RNA, a reflection of gene transcription, and GnRH mRNA suggest that NMA's effect on GnRH gene expression in the rat is likely due to post-transcriptional regulation. Despite the increasingly widespread use of transgenic mice, surprisingly little is known about the regulation of GnRH gene expression in the mouse. In this study, we assessed in detail the effects of NMA on GnRH gene expression in adult male mice. In the first experiment, GnRH mRNA levels in mice killed 60-min post-NMA injection (20 mg/kg bw, ip; n=9/treatment group) were lower (P<0.05) when compared to controls (saline vehicle). In the second experiment, mice (n=7/treatment group) were administered NMA or saline vehicle and were killed at 15-, 60- and 120-min post-injection. Consistent with the first experiment, treatment with NMA resulted in a significant decrease (P<0.05) in cytoplasmic GnRH mRNA compared to control levels at 15- and 60-min but not 120-min. NMA treatment decreased the nuclear GnRH primary transcript RNA at 120-min but not at earlier time points. In summary, we have shown that regulation by NMA of GnRH gene expression in mice differs substantially from rats. This differential regulation of GnRH gene expression between rats and mice warrants further investigation.

Differential subcellular distribution of neurolysin (EC 3.4.24.16) and thimet oligopeptidase (EC 3.4.24.15) in the rat brain

Immunohistochemistry was used to analyze the rat brain distribution of thimet oligopeptidase and neurolysin. Both enzymes appear ubiquitously distributed within the entire rat brain. However, neuronal perikarya and processes stained for neurolysin, while intense nuclear labeling was only observed for thimet oligopeptidase. These data suggest that neurolysin and thimet oligopeptidase, endopeptidases sharing several functional and structural similarities, are present in distinctive intracellular compartments in neuronal cells.

Marie Unna congenital hypotrichosis: clinical description, histopathology, scanning electron microscopy of a previously unreported large pedigree

Marie Unna congenital hypotrichosis (MUCH) is a rare autosomal dominant condition in which abnormalities are confined to hair shaft structure and hair density. We report a six-generation pedigree consisting of 59 members of whom 16 are affected; nine identified affected individuals are living. Affected individuals are born with adequate, normal to coarse hair. During early infancy the scalp hair becomes more coarse and wiry and stands out from the head. All affected individuals have sparse to absent eyebrows, eyelashes and body hair including secondary sexual hair. In some individuals, scalp hair is progressively lost beginning at puberty or beyond, until only a sparse fringe in the tonsorial distribution remains. The hair shafts are uniformly increased in diameter, measuring up to 0.12 mm. Individual hair shafts are deeply pigmented, variable in diameter, twisted, and bent at odd angles; some have a longitudinal groove visible on scanning electron microscopy. Cross-sectional shapes are variable and irregular, exhibiting oval, angular to reniform shapes. Multiple anagen hairs are extractable on gentle hair pull. Other ectodermal structures are unaffected except for exceptionally widely spaced upper incisor teeth seen in 50% of affected individuals. Histologically, there are dramatically reduced numbers of follicles per unit area, averaging nine total hairs per 4 mm cross-section as compared with a normal of 40. A mild to moderate inflammatory infiltrate is present, but little fibrosis and no scarring. The mechanism of progressive hair loss is unknown.

Late pelvic recurrence of nonseminomatous testicular carcinoma after negative retroperitoneal lymph node dissection

We report a case of pathologic Stage I teratoma recurring in the pelvis as embryonal carcinoma 12 years after radical orchiectomy and bilateral retroperitoneal lymph node dissection (RPLND). The patient received three cycles of chemotherapy (cisplatin, etoposide, bleomycin) followed by complete surgical excision of the pelvic mass. Successful treatment of these rare late recurrences usually requires chemotherapy and complete surgical excision. Pelvic relapse may potentially result from incomplete iliac node resection at the time of RPLND, altered lymphatic drainage from an incompletely resected spermatic cord, or a second primary extragonadal tumor focus. Our case emphasizes the importance of meticulous surgical technique during RPLND and the necessity for follow-up beyond 5 years in patients with testicular cancer.

Clinical dose ranging studies with finasteride, a type 2 5alpha-reductase inhibitor, in men with male pattern hair loss

BACKGROUND

Androgenetic alopecia is a common condition of adult men. Finasteride, a type 2 5alpha-reductase inhibitor, decreases the formation of dihydrotestosterone from testosterone.

OBJECTIVE

Two separate clinical studies were conducted to establish the optimal dose of finasteride in men with this condition.

METHODS

Men from 18 to 36 years of age with moderate vertex male pattern hair loss received finasteride 5, 1, 0.2, or 0.01 mg/day or placebo based on random assignment. Efficacy was determined by scalp hair counts, patient self-assessment, investigator assessment, and assessment of clinical photographs. Safety was assessed by clinical and laboratory measurements and by analysis of adverse experiences.

RESULTS

Efficacy was demonstrated for all end points for finasteride at doses of 0.2 mg/day or higher, with 1 and 5 mg demonstrating similar efficacy that was superior to lower doses. Efficacy of the 0.01 mg dose was similar to placebo. No significant safety issues were identified in the trials.

CONCLUSION

Finasteride 1 mg/day is the optimal dose for the treatment of men with male pattern hair loss and was subsequently identified for further clinical development.

Fasting regulates hypothalamic neuropeptide Y, agouti-related peptide, and proopiomelanocortin in diabetic mice independent of changes in leptin or insulin

Fasting increases hypothalamic neuropeptide Y (NPY) and agouti-related peptide (AGRP) messenger RNA (mRNA) and reduces hypothalamic POMC mRNA, and is also characterized by a reduction in plasma leptin, insulin, and glucose, each of which has been implicated in the regulation of hypothalamic gene expression. To further evaluate the roles of leptin, insulin, and glucose in mediating effects of fasting, we examined hypothalamic gene expression in nondiabetic and streptozotocin (STZ)-induced diabetic mice both under ad lib fed and 48-h fasted conditions. In both diabetic and nondiabetic mice, fasting stimulated hypothalamic NPY and AGRP mRNA and inhibited hypothalamic POMC mRNA and adipose leptin mRNA. However, in diabetic mice fasting had no effect on plasma leptin and insulin while decreasing plasma glucose, whereas in nondiabetic mice fasting decreased plasma leptin, insulin, and glucose. Furthermore, in nondiabetic fasted mice, NPY and AGRP mRNA were higher, and POMC mRNA and plasma glucose were lower, than in diabetic ad lib fed mice, even though insulin and leptin were similar in these two groups. These data are consistent with the hypothesis that although leptin and insulin regulate hypothalamic gene expression, glucose or other factors may have independent effects on hypothalamic and adipose gene expression under conditions of low insulin and leptin.

Secretion of metalloendopeptidase 24.15 (EC 3.4.24.15)

The metalloendopeptidase EP24.15 (EC3.4.24.15) is a neuropeptide-metabolizing enzyme present in neural and endocrine tissues, presumably functioning extracellularly. Because the majority of the EP24.15 activity is identified in the soluble fraction of cellular homogenates, suggesting that the enzyme is primarily an intracellular protein, we addressed the issue of how EP24.15 arrives in the extracellular environment. We utilized a model system of neuroendocrine secretion, the AtT20 cell. According to both enzymatic activity and immunologic assays, EP24.15 was synthesized in and released from AtT20 cells. Under basal conditions and after stimulation by corticotropin-releasing hormone or the calcium ionophore A23187, EP24.15 activity accumulated in the culture medium. This secretion was not attributable to cell damage, as judged by the absence of release of cytosolic enzyme markers and the ability to exclude trypan blue dye. Pulse-chase analysis and subcellular fractionation of AtT20 cell extracts suggested that the mechanism of EP24.15 secretion is not solely via classical secretory pathways. Additionally, drugs which disrupt the classical secretory pathway, such as Brefeldin A and nocodazole, blocked A23187-stimulated EP24.15 release yet had no effect on basal EP24.15 release, suggesting differences in the basal and stimulated pathways of secretion for EP24.15. In summary, EP24.15 appears to be secreted from AtT20 pituitary cells into the extracellular milieu, where the enzyme can participate in the physiologic metabolism of neuropeptides.

Immediate and postoperative complications of transurethral prostatectomy in the 1990s

PURPOSE

We compare the morbidity, mortality, hospitalization and urethral catheter time of contemporary transurethral prostatectomy to historical series, and evaluate recent trends in hospitalization and urethral catheter time during the last 8 years.

MATERIALS AND METHODS

A retrospective chart review of 520 consecutive patients who underwent transurethral prostatectomy between 1991 and 1998 at a single institution for symptomatic benign prostatic hyperplasia was performed. Inpatient and outpatient charts, clinic records, operative reports and discharge summaries were reviewed. For each patient 43 data points were collected. Telephone followup was performed when data were lacking. All retrieved data were compiled in a computer database. Perioperative and late postoperative morbidity and mortality, hospitalization and urethral catheter time were analyzed.

RESULTS

A total of 520 patients were identified with an average age of 67 years (range 44 to 89). Significant co-morbidity (2 or more co-morbid disease processes) was identified preoperatively in 30.3% of the patients. The most common indications for transurethral prostatectomy were lower urinary tract symptoms (80.9%) and urinary retention (15.2%). Average preoperative International Prostate Symptom Score was 23.8. Average weight of resected tissue was 18.8 gm. There was no perioperative patient mortality. Blood transfusion rate was 0.4%. The rate of intraoperative and immediate postoperative complications was 2.5% and 10.8%, respectively. Average hospital stay was 2.4 days, and 1.1 from 1997 through 1998. The rate of late postoperative complication was 8.5% and the average postoperative symptom score was 6.4 with an average followup of 42 months (range 6 to 84).

CONCLUSIONS

Contemporary perioperative and postoperative complications of transurethral prostatectomy are significantly lower than rates in historical series. The average hospital stay and urethral catheter time have steadily decreased during the last 8 years.

The association of metalloendopeptidase EC 3.4.24.15 at the extracellular surface of the AtT-20 cell plasma membrane

Endopeptidase EC 3.4.24.15 (EP24.15) is a soluble, neuropeptide-degrading metalloenzyme, widely expressed in the brain, pituitary and gonads. For the physiological metabolism of neuropeptides, the enzyme should be located extracellularly, either associated with the plasma membrane or in the extracellular milieu. Western immunoblot analyses of crude cytosolic and post-nuclear membrane fractions prepared by differential centrifugation revealed a slightly smaller molecular mass ( approximately 2 kDa) for EP24.15 in the post-nuclear membrane fraction. This smaller EP24.15 species was also present in an enriched fraction of plasma membrane prepared by Percoll gradient centrifugation. To ascertain whether EP24.15 is associated with the extracellular surface of plasma membrane, two sets of experiments were carried out. First, Western immunoblot analysis of AtT-20 cells treated with the membrane-impermeable, thiol-cleavable cross-linker, 3, 3'-dithio-bis(sulpho-succinimidyl-propionate) (DTSSP), indicated an extracellular membrane association. After cross-linking and thiol-reduction, a distinct band corresponding to EP24.15 was significantly diminished under non-reducing conditions. Second, immunocytochemical studies performed at 4 degrees C on non-permeabilized AtT-20 cells (i.e., non-fixed to prevent antibody internalization), indicated that EP24.15 was expressed on the surface of the AtT-20 cells. We furthermore determined that EP24.15 enzymatic activity is present on the extracellular surface of the cell discernable from the secreted enzyme. These results suggest that the EP24.15 is associated with the extracellular surface of the AtT-20 cell plasma membrane and is enzymatically active. Taken together, the results are consistent with a putative role in the degradation of neuropeptides acting at the external cell surface.

Targeted deletion of the Vgf gene indicates that the encoded secretory peptide precursor plays a novel role in the regulation of energy balance

To determine the function of VGF, a secreted polypeptide that is synthesized by neurons, is abundant in the hypothalamus, and is regulated in the brain by electrical activity, injury, and the circadian clock, we generated knockout mice lacking Vgf. Homozygous mutants are small, hypermetabolic, hyperactive, and infertile, with markedly reduced leptin levels and fat stores and altered hypothalamic proopiomelanocortin (POMC), neuropeptide Y (NPY), and agouti-related peptide (AGRP) expression. Furthermore, VGF mRNA synthesis is induced in the hypothalamic arcuate nuclei of fasted normal mice. VGF therefore plays a critical role in the regulation of energy homeostasis, suggesting that the study of lean VGF mutant mice may provide insight into wasting disorders and, moreover, that pharmacological antagonism of VGF action(s) might constitute the basis for treatment of obesity.

Mechanisms for the regulation of gonadotropin-releasing hormone gene expression in the developing mouse

The release of GnRH peptide from neuroterminals in the median eminence increases during postnatal development. We were interested in determining the biosynthetic component contributing to the regulation of GnRH decapeptide levels, and ascertaining the molecular mechanism for these changes. Male and female C57bl/6 mice, from embryonic day (E)16 through postnatal day (P)60, were killed, and the preoptic area-anterior hypothalamus was dissected out. Cytoplasmic and nuclear RNA were extracted separately. Levels of GnRH messenger RNA (mRNA) and primary transcript were quantitated in individual preoptic area-anterior hypothalamus cytoplasmic and nuclear fractions, respectively, by ribonuclease protection assays. Serum LH levels were assayed by RIA. GnRH mRNA levels in the cytoplasm increased gradually and significantly during postnatal development in both males and females, reaching a peak at P55 in females and P40 in males. GnRH primary transcript levels in the nucleus, an index of GnRH gene transcription, changed in a completely different manner developmentally, and they differed between male and female mice. GnRH primary transcript levels in males were quite low until P5, when they underwent an increase of approximately 4-fold, between P5 and P7. They continued to increase through P15, at which time they reached adult levels. In females, GnRH primary transcript levels were high at E16, decreased to a nadir at P5, and then underwent an increase of approximately 5-fold to P7, which were comparable with adult levels. The large and sexually dimorphic changes in GnRH primary transcript between E16 and P7, in the absence of similar changes in GnRH mRNA, suggest that differential mechanisms, such as gene transcription and mRNA stability, play a role in determining levels of GnRH mRNA at different stages of development.