Changes in immune cell counts and interleukin (IL)-1beta production in humans after a somnogenically active growth hormone-releasing hormone (GHRH) administration

Growth hormone-releasing hormone (GHRH) has been shown to enhance slow-wave sleep (SWS) and non-rapid eye movement sleep in animals and humans. In animals the somnogenic effect of interleukin (IL)-1beta appears to be mediated by GHRH. Neuroimmunological interactions in sleep are most frequently studied in humans by sleep deprivation or by cytokine administration. The present study, in contrast, investigates in humans the effect of enhanced sleep through GHRH administration on selected immune parameters. Results reveal that a single intravenous bolus of 50 microg GHRH which enhanced SWS stage 4 in the first half of the night suppressed circulating suppressor T cell (CD3+/CD8+) numbers, with a similar tendency for B cells (CD19+) and suppressed mitogen-stimulated IL-1beta production. When the same amount of GHRH was administered distributed across five repetitive boluses of 10 microg GHRH within 1 h, neither corresponding sleep nor immune parameters were changed significantly compared to placebo. These data suggest that GHRH can modulate immune functions through brain mechanisms which are also involved in the regulation of sleep.

Insecticidal proteins from Bacillus thuringiensis protect corn from corn rootworms

Field tests of corn co-expressing two new delta-endotoxins from Bacillus thuringiensis (Bt) have demonstrated protection from root damage by western corn rootworm (Diabrotica virgifera virgifera LeConte). The level of protection exceeds that provided by chemical insecticides. In the bacterium, these proteins form crystals during the sporulation phase of the growth cycle, are encoded by a single operon, and have molecular masses of 14 kDa and 44 kDa. Corn rootworm larvae fed on corn roots expressing the proteins showed histopathological symptoms in the midgut epithelium.

A high-throughput assay for mitochondrial membrane potential in permeabilized yeast cells

A fluorometric assay for mitochondrial membrane potential in permeabilized yeast cells has been developed. This method involves permeabilizing the plasma membrane and measuring the distribution of a mitochondrial membrane potential sensitive probe 3,3'-dipropylthiadicarbocyanine iodide (DiSC(3)(5); DiSC(3)). In permeabilized cells, DiSC(3) fluorescence decreased when introduced into energized mitochondria and increased three- to sixfold when the mitochondrial membrane potential was dissipated by the chemical uncoupler carbonylcyanide m-chlorophenyl hydrazone. Plasma membrane potential was abolished by permeabilization, as shown by a lack of polarization of the plasma membrane induced by K(+) and glucose. Uncoupling protein 1 (UCP1), a mitochondrial H(+) transporter, was used as a model for method validation. The fluorescence intensity responded vigorously to specific modulators in UCP1-expressing cells. This method has been adapted as a high-throughput assay to screen for modulators of mitochondrial membrane potential.

Scalp recorded direct current (DC) potential shifts associated with food intake in hungry humans

In humans, eating is assumed to be regulated within a neuronal circuitry integrating hypothalamic "feeding centers" with neocortical regions. Here, DC potentials were recorded in food deprived men to demonstrate a graded tuning of neocortical excitability in conjunction with meal ingestion. In the beginning of food ingestion a pronounced negative DC potential shift developed (P<0.01) which was replaced by a gradual positive potential shift reaching a maximum within 5 min after cessation of food intake (P<0.05). Both negative and positive shifts showed a widespread cortical distribution. The initial negative DC potential presumably reflecting increased depolarisation of apical cortical dendrites, may serve to facilitate eating behavior. The succeeding positivity points to a growing inhibitory influence on cortical processing with increasing satiety that may support termination of meal intake.

Assessment of hearing in persons with learning disabilities: the Phoenix NHS Trust, January 1997 to September 1998

People with learning disabilities are at increased risk of impaired hearing. The aims of this study were to assess the prevalence of hearing impairment and ear disease in people attending the specialist Otolaryngology/Hearing Therapy clinic at the Phoenix NHS Trust, Bristol. The present and future process of such a service was explored. Data were obtained from the referral form and notes made by the consultant otolaryngologist. In 20 months, there were 226 consultations, 188 of which were new referrals. The majority of patients had verbal communication to some extent. Suspected infection/inflammation and unobtainable/abnormal tympanograms, each accounted for 43 per cent of reasons for referral. Twenty per cent of patients were normal otologically. Eighteen per cent were provided with hearing aids and nine per cent required surgery. Ten patients underwent brainstem evoked response testing, half of whom had aidable hearing. Our results are comparable to published data of similar units. It is recommended that combined otolaryngology/specialist hearing therapy services are continued and further developed.

Dimensional complexity and power spectral measures of the EEG during functional versus predicative problem solving

Electroencephalograms were recorded in 22 men while solving tasks of visual-pattern completion and during mental relaxation. They were primed (by foregoing trials) to solve these tasks either in a predicative or functional mode of thinking. Predicative thinking required that in order to complete the pattern the subject had to get involved with the logic of the static structure of the pattern and therefore had to recognize the recurrence of certain features of the elements (e.g., shape, color, and size). Functional thinking required involvement in a dynamic reading of the logic of the pattern and therefore to search for operations and actions to be performed on the pattern elements (e.g., pushing, mirroring, and rotating). The EEG complexity during predicative thinking decreased in comparison to functional thinking and mental relaxation, with this reduction being most pronounced over the right parietal cortex. A reduction in dimensional complexity during functional thinking as compared to mental relaxation, which was concentrated over the left central cortex, although significant, was less clear. The reduced EEG complexity during predicative thought, dominant over the right hemisphere, could reflect increased competitive inhibition among respective cortical neuron assemblies in association with the visual analysis of static element features, converging upon those predicates relevant for the solution.

Slow cortical DC-potential responses to sweet and bitter tastes in humans

Processing of hedonic stimulus quality is assumed to be accompanied by a tuning of cortical arousal and excitability. In this pilot study in 11 healthy humans scalp-recorded DC potentials were assessed during application of a sweet (sucrose) and bitter (quinine hydrochloride) taste, i.e., primary reinforcers of positive and negative quality. Muscular, ocular, and skin potential activity were controlled. Application of sucrose induced a widespread positive DC-potential shift with an amplitude of 40-50 microV and persisting for more than 120-s post-stimulus onset. Following administration of quinine hydrochloride, this positive shift was reduced, most distinctly between 48- and 88-s post-stimulus onset. The reduction appeared to be most consistent at anterior midline recording sites (Fz, Cz). It is assumed that the higher DC-potential positivity during sweetness than during bitterness points to a differential tuning of cortical excitability by a widespread decrease in depolarization of apical dendrites.

Changes in direct current (DC) potentials and infra-slow EEG oscillations at the onset of the luteinizing hormone (LH) pulse

An essential function of the neuroendocrine system lies in the coordination of hypothalamo-pituitary secretory activity with neocortical neuronal activity. Cortical direct current (DC) potential shifts and EEG were monitored in conjunction with the circulating concentration of luteinizing hormone (LH) in humans while asleep to assess a hypothalamic-neocortical interaction. The onset of an LH pulse was accompanied (i) at frontocortical locations by a transient positive DC potential shift of approximately 3 min duration and peak amplitude 50 microV; (ii) at frontal and central locations by an increase in power of infra-slow EEG oscillations for periodicities between 64 and 320 s. Results uniquely demonstrate a coupling of hypothalamo-pituitary activity with regulation of neocortical excitability.

Scalp recorded direct current potential shifts associated with quenching thirst in humans

As an indicator of cortical excitability, direct current (DC) potentials were recorded from thirsted subjects before, during and after drinking 400 ml of water. Self-rated thirst was distinctly reduced after drinking. Compared with control conditions in which the subjects remained thirsty, during drinking a widespread negative potential shift occurred averaging over -70 microV at Cz. At the transition from the consumatory phase to the postconsumption phase, a slow positive potential shift commenced that was most pronounced over the anterior cortex (averaging over +40 microV at Fz) and persisted for more than 3 min after drinking. Control conditions excluded muscle activity, ocular movements, and changes in body fluid and serum osmolality as possible non-neuronal sources of the DC-potential changes. The sequence of negative and positive potential shifts associated with drinking indicates a coordinate regulation of cortical excitability that may facilitate consumatory behavior and its context-dependent encoding into memory.

Evaluation of real-time imaging using a laparoscopic ultrasound probe during operative endoscopic procedures

OBJECTIVES

To evaluate rigid and flexible ultrasound transducers introduced through a laparoscopic port to image pelvic anatomy during operative endoscopy as a means of mapping the pelvic anatomy, detecting pathology, and for real-time tracking of intra-uterine procedures.

DESIGN

Prospective, descriptive, non-comparative.

MATERIALS AND METHODS

Laparoscopy, hysteroscopy and real-time, gray-scale ultrasonography were performed simultaneously in 36 patients. Laparoscopic ultrasound was performed using 10 mm diameter, 7.5 MHz gray-scale rigid and steerable transducers for imaging of the ovaries and uterus during operative endoscopy (Aloka, Wallingford, CT, USA). All patients underwent intra-operative evaluation using this probe to assess uterine and ovarian structures and to track instruments intra-operatively during complex intra-uterine hysteroscopic procedures and for intra-operative sonohysterography.

RESULTS

Laparoscopic ultrasound provided visualization of structures and delineation of ovarian anatomy needle placement for tracking microscissors and intra-operative sonohysterography. The ultrasonography provided information useful for determining the configuration of normal anatomic structures, the localization of and more precise incision placement for anatomic abnormalities and for intra-operative guidance during hysteroscopic resection of intra-uterine adhesions. The imaging also provided details of intra-uterine anatomy through sonohysterography performed during chromotubation. However, no additional information regarding ovarian or uterine abnormalities was noted beyond that detected on pre-operative transvaginal ultrasonography. No technical problems were encountered. No additional operative time was required.

CONCLUSIONS

Real-time laparoscopic ultrasound imaging is useful in monitoring complex intra-uterine operative procedures and in detailing intra-uterine anatomy during intra-operative sonohysterography. However, it did not provide more enhanced imaging of ovarian anatomy beyond images obtained with pre-operative transvaginal imaging. This imaging technique may have broad application for a variety of endoscopic operative procedures with the potential to impact on operative decision-making and requires further evaluation.

Prolonged hypernatremia controls elevated intracranial pressure in head-injured pediatric patients

OBJECTIVE

To determine the effects continuous infusions of hypertonic saline (3% NaCl) on intracranial pressure (ICP) control and describe the physiologic effects of hypertonic saline administered to closed head injury children.

DESIGN

Retrospective chart review.

SETTINGS

Pediatric intensive care unit of a children's hospital.

PATIENTS

Sixty-eight children with closed head injury.

INTERVENTIONS

Intravenous infusion of 3% hypertonic saline to increase serum sodium to levels necessary to reduce ICP < or =20 mm Hg.

MEASUREMENTS AND MAIN RESULTS

The patients enrolled had similar Injury Severity Scores. Treatment effectively lowered ICP in these patients and ICP was under good control a majority of the time. Only three patients (4%) died of uncontrolled elevation of ICP. No adverse effects of supraphysiologic hyperosmolarity such as renal failure, pulmonary edema, or central pontine demyelination, were noted.

CONCLUSIONS

Hypertonic saline administration to children with closed head injury appears to be a promising therapy for control of cerebral edema. Further controlled trials are required to determine the optimal duration of treatment before widespread use is advocated.

Traumatic brain injury: patterns of failure of nonoperative management

OBJECTIVE

The circumstances of failure for nonoperative management of blunt traumatic brain injury have been poorly defined. In this study, all trauma patients identified over a 12-year period with progression of neurologic injury requiring craniotomy were retrospectively reviewed.

METHODS

Data collected included demographic information, mechanism of injury, field and admission vital signs, and Glasgow Coma Scale score, medications, associated injuries, and coagulopathy. Head computed tomographic scans were reviewed, and anatomic findings were correlated with clinical changes (change in mental status or elevation of intracranial pressure) that led to subsequent CT scan and craniotomy.

RESULTS

Of 20,100 patients, there were 852 who had computed tomographic scans with acute intracranial injuries on admission; 462 patients were managed nonoperatively. Fifty-seven patients had progression of neurologic injury (34 < 24 hours = early; 23 > 24 hours = late) that required surgery.

CONCLUSION

Of the variables investigated, only anatomic location of injury was found to be predictive of early failure of nonoperative management. Frontal intraparenchymal hematomas are particularly prone to early failure. Clinical examination and intracranial pressure monitoring are equally important in detecting failure and should be an integral part of nonoperative management.

Identification of best practices in the delivery of patient food services through public/private sector partnerships

This article describes the evolution of public/private sector partnership in patient food service delivery and identifies skills required by executives to manage partnerships effectively, features that may be generalized to other areas; and the importance of labour relations. Site visits conducted across Canada demonstrate that when partners understand each other's objectives, commit to providing strong leadership, and create meaningful labour relations and communications strategies, partnerships can be successful.

Intramuscular opioids for maternal pain relief in labour: a randomised controlled trial comparing pethidine with diamorphine

OBJECTIVE

To compare the pain relief and side effects of intramuscular pethidine with intramuscular diamorphine in labour.

DESIGN

Double-blind randomised controlled trial.

SETTING

The labour ward in a UK teaching hospital.

PARTICIPANTS

Sixty-nine nulliparous women and 64 multiparous women in labour who requested narcotic analgesia and remained undelivered one hour after trial entry.

METHODS

Nulliparous women were randomised to receive either 150 mg intramuscular pethidine or 7.5 mg intramuscular diamorphine. Multiparous women were randomised to receive either 100 mg intramuscular pethidine or 5 mg intramuscular diamorphine. All participants received the anti-emetic prochloroperazine at the same time as the trial drugs.

MAIN OUTCOME MEASURES

Maternal analgesia assessed by a visual analogue score and verbal scales of pain intensity and pain relief, maternal sedation and vomiting, neonatal outcome assessed by Apgar scores and the need for resuscitation.

RESULTS

More women allocated to receiving pethidine than to diamorphine reported slight or no pain relief at 60 minutes after administration of these drugs (P = 0.03). This trend was repeated in most of the other measures for maternal analgesia. There was no difference in maternal sedation, but the incidence of vomiting within 60 minutes was lower for women who received diamorphine (P = 0.02). Pethidine was associated with lower Apgar scores at 1 minute (P < 0.05).

CONCLUSION

Intramuscular diamorphine in labour appears to have some benefits, compared with intramuscular pethidine, but the trial was small and further research, particularly into alternative opioids and long term effects on the infants is still needed.

Sleep and endocrine changes after intranasal administration of growth hormone-releasing hormone in young and aged humans

Systemic administration of growth hormone-releasing hormone (GHRH) has been found to improve human sleep in previous studies. Here we examined effects of GHRH on endocrine function and sleep after intranasal administration, a method which based on previous studies appears to enable a direct effect of peptides on brain function. Also, it was hypothesized that elderly humans displaying deficient GH release and sleep, benefit from GHRH administration more than young subjects. A study was performed according to a double-blind cross-over design. Each of 12 young and 11 old healthy men were intranasally administered with 300 micrograms GHRH (vs. placebo) 30 min before bedtime at 23:00 h. Sleep was recorded polysomnographically until 07:00 h and blood was collected in 15 min intervals for determination of cortisol and GH. Apart from the well-known age-related changes of hormonal secretion and sleep, intranasal GHRH reduced cortisol nadir concentrations in the beginning of sleep (P < 0.05), and also reduced the sleep-induced elevation in GH concentrations during early sleep. Moreover, results indicated that after intranasal administration GHRH increased rapid-eye-movement (REM) sleep and slow wave sleep (SWS), with this influence concentrating on the second half of sleep time. Effects of GHRH did not depend on the subject's age. We conclude that there is a coordinate influence of intranasal GHRH on the central nervous regulation of sleep processes and of hypothalamic-hypophysiotropic secretory activity in both young and elderly men. The effects may mimic the dual neuronal and endocrine function of hypothalamic GHRH activity.

A new coaxial catheter system with an echodense tip for ultrasonographically guided embryo transfer

OBJECTIVES

To determine performance of a new coaxial catheter system with an echodense tip for imaging during transabdominal ultrasonographically guided catheter passage.

DESIGN

Prospective, descriptive, noncomparative study.

SETTING

Fertility center within a tertiary care center.

PATIENT(S)

Twenty-five patients who were undergoing ET.

INTERVENTION(S)

The catheter was passed transcervically under transabdominal ultrasonographic guidance.

MAIN OUTCOME MEASURE(S)

The catheter was assessed for ease of placement and immediacy of identification of the outer and inner sheaths and the degree of catheter movement (if any) needed for identification.

RESULTS

The outer sheath of the system was well visualized through the cervix and into the lower uterine segment due to its thickness. Immediate recognition of the echodense tip of the inner sheath was achieved in all patients. With minimal movement of the catheter or ultrasonographic transducer, the tip could be easily tracked during passage through the entire uterine cavity into the fundal region.

CONCLUSIONS

In this preliminary study, the echodense tip was immediately identified by transabdominal imaging, reducing the need to move the catheter for identification. Previous investigations have not conclusively shown improved pregnancy rates with ultrasonographic guidance, possibly because of the need for catheter movement for identification of the tip and resultant disruption of the endometrium. The immediate identification of the catheter may provide a method for precise, atraumatic ET.

A determinant factor in the efficacy of GHRH administration in promoting sleep: high peak concentration versus recurrent increasing slopes

A previous experiment indicated a greater efficacy of episodic than continuous growth hormone (GH)-releasing hormone (GHRH) administration in enhancing sleep. The greater efficacy of episodic administration could principally result from two factors, i.e. the greater peak concentration reached after episodic administration or the recurrence of increasing slopes in GHRH concentration. In order to investigate which factor essentially determines the pharmacodynamics of sleep promotion after GHRH, effects after a transient high peak in GHRH concentration were compared with those of repetitive increases in GHRH concentration. Sleep, plasma concentrations of GH, and GHRH were examined in healthy subjects after evening administration of a 'single' i.v. bolus of 50 micrograms GHRH, after five 'repetitive' boluses of 10 micrograms GHRH, and after placebo. Compared with placebo, single GHRH significantly increased time spent in stage 4 sleep (p < .01) and in stage 2 sleep, reduced time spent in wakefulness and onset latency of stage 4 sleep (p < .05, for each), while repetitive GHRH remained without effects. GH secretory activity also tended to be higher after single than repetitive GHRH. Thus, results suggest the relevance of a transiently high concentration of GHRH in blood as an essential factor in enhancing the central nervous sleep process.