Reversal of opioid-induced bladder dysfunction by intravenous naloxone and methylnaltrexone.

Peripheral mechanisms may be involved in opioid actions on the urinary bladder. This double-blind study investigated whether opioid inhibition of bladder function is reversed by methylnaltrexone, a peripheral opioid antagonist. Thirteen healthy male volunteers received an intravenous (i.v.) infusion of remifentanil, 0.15 mcg/kg/min, then a single i.v. dose of study medication (methylnaltrexone 0.3 mg/kg, naloxone 0.01 mg/kg, or saline). Urodynamics were measured with indwelling bladder and rectal catheters, and pupil size was assessed with infrared pupillometry. Remifentanil decreased detrusor pressure in 21/25 sessions and caused complete urinary retention in 18/25. Voiding was possible in 7/7, 5/12, and 0/6 sessions after naloxone, methylnaltrexone, and saline, respectively (P=0.0013). Remifentanil caused marked miosis that was reversed by naloxone, but not methylnaltrexone or placebo (P<0.0001). The pupil data confirm that methylnaltrexone did not reverse central opioid effects. Reversal of urinary retention by methylnaltrexone indicates that peripheral mechanisms may play a role in opioid-induced bladder dysfunction.

Differential gene expression in Symbiodinium microadriaticum clade B following stress.

Coral bleaching is caused by the loss of symbiont zooxanthellae and/or decrease in their pigments. Since the algal symbionts provide the energy basis for corals and whole reefs, their loss or impairment of function leads to widespread mortality. This phenomenon has been documented numerous times in recent years, and has extensively damaged coral reefs all over the world. Temperature has been found to be the major cause of bleaching, and rising sea temperatures have increased the frequency of these catastrophic episodes. To characterize the response of zooxanthellae to temperature stress at the molecular level, we used the mRNA differential display technique to monitor changes in the abundance of specific mRNA species in the cell under different temperature conditions. Axenically grown zooxanthellae were exposed to a range of temperatures (21.7, 17, 26 degrees C) before extraction of their mRNA. Of numerous differentially expressed sequences, seven mRNA species were amplified by the polymerase chain reaction (PCR) and sequenced. One of those sequences was positively identified as encoding a multifunction cell surface aminopeptidase, dipeptidyl peptidase IV, which is active in cell matrix adhesion. Our work illustrates the power of the differential display technique as a useful tool to study the response of zooxanthellae to stressors.

Diel 'tuning' of coral metabolism: physiological responses to light cues.

Hermatypic-zooxanthellate corals track the diel patterns of the main environmental parameters - temperature, UV and visible light - by acclimation processes that include biochemical responses. The diel course of solar radiation is followed by photosynthesis rates and thereby elicits simultaneous changes in tissue oxygen tension due to the shift in photosynthesis/respiration balance. The recurrent patterns of sunlight are reflected in fluorescence yields, photosynthetic pigment content and activity of the two protective enzymes superoxide dismutase (SOD) and catalase (CAT), enzymes that are among the universal defenses against free radical damage in living tissue. All of these were investigated in three scleractinian corals: Favia favus, Plerogyra sinuosa and Goniopora lobata. The activity of SOD and CAT in the animal host followed the course of solar radiation, increased with the rates of photosynthetic oxygen production and was correlated with a decrease in the maximum quantum yield of photochemistry in Photosystem II (PSII) (DeltaF'/F(m)'). SOD and CAT activity in the symbiotic algae also exhibited a light intensity correlated pattern, albeit a less pronounced one. The observed rise of the free-radical-scavenger enzymes, with a time scale of minutes to several hours, is an important protective mechanism for the existence and remarkable success of the unique cnidarian-dinoflagellate associations, in which photosynthetic oxygen production takes place within animal cells. This represents a facet of the precarious act of balancing the photosynthetic production of oxygen by the algal symbionts with their destructive action on all living cells, especially those of the animal host.

Disease status and use of ventilatory support by ALS patients. BDNF Study Group.

INTRODUCTION: Use of mechanical ventilation (MV), administered either invasively via tracheostomy, or more commonly non-invasively (CPAP, BiPAP), appears to be increasing in ALS. No prospective databases exist that describe the behavior of physicians and patients and the criteria for instituting MV in ALS. METHODS: 387 placebo patients in a Phase III trial of r-metHuBDNF were followed for 9 months. Although the use of MV was not the primary end-point of the trial, information was gathered regarding it by cataloging respiratory adverse events and tracking health resource utilization. RESULTS: 35 of 387 patients utilized MV during the trial. Twenty-eight (7%) patients received BiPAP. Seven (2%) were tracheotomized without first receiving BiPAP. Forced vital capacity (FVC): BiPAP patients had a mean ( SEM) FVC% of 71.8 +/- 2.8% and ALSFRS of 27.7 +/- 1.0 at baseline; non-BiPAP patients had a mean baseline FVC% of 88.7 +/- 1.0%, and an ALSFRS of 30.3 +/- 0.3. Symptom duration at entry was similar for both groups (2.1 +/- 0.4 years vs. 2.1 +/- 0.1 years). At the time of first use of BiPAP, average FVC% was 47.5 +/- 4.0% and ALSFRS score was 22.4 +/- 1.5. The range of FVC% at start of BiPAP was 15-87. The nine-month survival was 67.9% for BiPAP patients vs. 86% for non-BiPAP patients. The use of BiPAP varied tremendously among the 38 study sites, with some not employing it at all and others using it in as many as 40% of patients. CONCLUSIONS: Of the 9% of placebo patients who received MV, BiPAP patients were more rapidly progressing than non-BIPAP patients, and showed a greater eventual mortality rate. Patients began MV at a wide range of values of FVC%, and centers differed in their prescribing practices. Factors influencing BiPAP use are complex, and not strictly related to FVC%.

Recombinant human neurotrophic factors accelerate colonic transit and relieve constipation in humans.

BACKGROUND & AIMS: The aim of this study was to assess the effects of recombinant human brain-derived neurotrophic factor (r-metHuBDNF) and recombinant human neurotrophic factor 3 (r-metHuNT-3) on gastrointestinal motor functions in healthy people and in patients with constipation. METHODS: Gastrointestinal and colonic transit was measured by scintigraphy before and after 2 weeks of treatment. Daily diaries documented symptoms over 6 weeks before, during, and after treatment. In a randomized study of healthy subjects, 40 received 100 microg/kg r-metHuBDNF or placebo subcutaneously (SC) daily. In a separate study, 8 healthy subjects and 8 patients with constipation received 300 microg/kg r-metHuNT-3 SC thrice weekly. RESULTS: r-met-HuBDNF accelerated overall and proximal colonic emptying (P<0.05) in health. r-metHuNT-3 accelerated overall colonic transit in health and constipation (all P<0.05) and gastric and small bowel transit (both P<0.05) in health. r-metHuBDNF tended to increase stool frequency compared with placebo in health (P = 0.09). r-metHuNT-3 increased stool frequency (P = 0.05) and facilitated passage of stool (P < 0.01) in constipated patients. The effects on stool frequency started within 3 days of the beginning of neurotrophin administrations and lasted up to 5 days after treatment ended. r-metHu neurotrophic factors were well tolerated, although half of the participants in the 2 studies developed injection site reactions or paresthesiae. CONCLUSIONS: Exogenous neurotrophic factors stimulate human gut motility in health and constipation.

The ALSFRS-R: a revised ALS functional rating scale that incorporates assessments of respiratory function. BDNF ALS Study Group (Phase III).

The ALS Functional Rating Scale (ALSFRS) is a validated rating instrument for monitoring the progression of disability in patients with amyotrophic lateral sclerosis (ALS). One weakness of the ALSFRS as originally designed was that it granted disproportionate weighting to limb and bulbar, as compared to respiratory, dysfunction. We have now validated a revised version of the ALSFRS, which incorporates additional assessments of dyspnea, orthopnea, and the need for ventilatory support. The Revised ALSFRS (ALSFRS-R) retains the properties of the original scale and shows strong internal consistency and construct validity. ALSFRS-R scores correlate significantly with quality of life as measured by the Sickness Impact Profile, indicating that the quality of function is a strong determinant of quality of life in ALS.

A retrospective study of percutaneous endoscopic gastrostomy in ALS patients during the BDNF and CNTF trials.

Percutaneous endoscopic gastrostomy (PEG) provides a reliable route for nutrition and hydration in ALS patients with dysphagia. We performed a retrospective analysis of the CNTF and BDNF databases to determine the clinical status of ALS patients within 30 days preceding PEG insertion. This analysis revealed an approximately 50% reduction of function across multiple measures of ALS disease status. A trend to earlier intervention with PEG was apparent upon review of published studies and the CNTF and BDNF studies. By comparing the rate of decline pre- and post-PEG, nutritional supplementation via PEG stabilized the weight loss experienced by patients. Death within 30 days post-PEG was associated with a marked reduction in forced vital capacity (FVC) and identified a group of ALS patients in whom PEG should be cautiously performed. These data emphasize the importance of sequential measurement of FVC in managing ALS patients to guide the timing of nutritional intervention with PEG.

Physiological characterization of Taxol-induced large-fiber sensory neuropathy in the rat.

The cancer chemotherapeutic agent Taxol (paclitaxel) causes a dose-related peripheral neuropathy in humans. We produced a dose-dependent large-fiber sensory neuropathy, without detrimental effects on general health, in mature rats by using two intravenous injections 3 days apart. Tests of other dosing schedules demonstrated the dependence of the severity of the neuropathy and of animal health on both the dose and the frequency of dosing. Pathologically, severe axonal degeneration and hypomyelination were observed in sections of dorsal roots, whereas ventral roots remained intact. Electrophysiologically, H-wave amplitudes in the hindlimb and amplitudes of predominantly sensory compound nerve action potentials in the tail were reduced. These effects persisted for at least 4 months after treatment. Motor amplitudes were not affected, but both motor and sensory conduction velocities decreased. The ability of rats to remain balanced on a narrow beam was impaired, indicating proprioceptive deficits. Muscle strength, measured by hindlimb and forelimb grip strength, and heat nociception, measured by tail-flick and hindlimb withdrawal tests, were not affected by Taxol. This model of Taxol-induced neuropathy in mature rats, with minimal effects on general health, parallels closely the clinical syndrome observed after Taxol treatment in humans.

Prognostic indicators of survival in ALS. ALS CNTF Treatment Study Group.

We analyzed data from the 245-patient placebo group of the ALS CNTF Treatment Study Group study, a large, prospective, multicenter study of recombinant human ciliary neurotrophic factor to determine prognostic factors for length of survival in ALS. Variables examined included baseline demographic characteristics, indices of disease severity, pulmonary function, and clinical laboratory tests. Shorter survival was associated with greater age, lower percent-predicted forced vital capacity (FVC%), and lower serum chloride at study entry. A shorter interval from symptom onset to diagnosis of ALS and greater weight loss in the 2 months before study entry also predicted shortened survival times. The rate of muscle strength loss before study entry did not predict risk of mortality. Serum chloride, reflecting the degree of respiratory acidosis, was identified for the first time as being correlated with prognosis in ALS. The relationship between a patient's FVC% and the probability of survival is described.

Performance of the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS) in multicenter clinical trials.

The Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS) is a 10-item functional inventory which was devised for use in therapeutic trials in ALS. Each item is rated on a 0-4 scale by the patient and/or caregiver, yielding a maximum score of 40 points. The ALSFRS assesses patients' levels of self-sufficiency in areas of feeding, grooming, ambulation and communication. Rotated factor analysis of the ALSFRS found that the rating items group logically and consistently into four categories. The ALSFRS has been validated both cross-sectionally and longitudinally against muscle strength testing, the Schwab and England ADL rating scale, the Clinical Global Impression of Change (CGIC) scale, and independent assessments of patient's functional status. In this report, we use the data provided by the placebo patients who participated in the ALS CNTF Treatment Study (ACTS) to demonstrate the robustness, test-retest reliability and consistency of the ALSFRS as employed in a large, multicenter clinical trial.

Premenstrual mood changes. Characteristic patterns in women with and without premenstrual syndrome.

Methodologic errors have compromised previous attempts to establish the relationship between mood and menstruation in women with the premenstrual syndromes. These syndromes cannot be diagnosed by history and require confirmation with longitudinal, prospective ratings. In this paper we present the characteristic pattern of mood changes in women with and without menstrually-related mood syndrome. The theoretical and diagnostic implications of the pattern differences are discussed.