Pharmacokinetics of Intranasal Amiloride in Healthy Volunteers

Anxiety and panic disorders are the most common mental illnesses in the United States and lack effective treatment options. Acid-sending ion channels (ASICs) in the brain were shown to be associated with fear conditioning and anxiety responses and therefore are potential targets for treating panic disorder. Amiloride is an inhibitor of the ASICs in the brain and was shown to reduce panic symptoms in preclinical animal models. An intranasal formulation of amiloride will be highly beneficial to treat acute panic attacks due to advantages such as the rapid onset of action and patient compliance. The aim of this single-center, open-label trial was to evaluate the basic pharmacokinetics (PK) and safety of amiloride after intranasal administration in healthy human volunteers at three doses (0.2, 0.4, and 0.6 mg). Amiloride was detected in plasma within 10 minutes of intranasal administration and showed a biphasic PK profile with an initial peak within 10 minutes of administration followed by a second peak between 4-8 hours of administration. The biphasic PK indicates an initial rapid absorption via the nasal pathway and later slower absorption by non-nasal pathways. Intranasal amiloride exhibited a dose-proportional increase in the area under the curve and did not exhibit any systemic toxicity. These data indicate that intranasal amiloride is rapidly absorbed and safe at the doses evaluated and can be further considered for clinical development as a portable, rapid, noninvasive, and nonaddictive anxiolytic agent to treat acute panic attacks.

How I Do It: Endonasal transethmoidal, transcribriform approach for resection of giant olfactory groove meningioma

BACKGROUND

Olfactory groove meningiomas (OGMs) arise from the cribriform plate of the anterior fossa and account for 9-12% of all meningiomas. Giant OGMs are those larger than 6 cm and are technically challenging to resect.

METHOD

Here we present the surgical decision-making and intraoperative details regarding the endonasal endoscopic resection of an OGM using a minimally invasive, endonasal approach in a 68-year-old female patient.

CONCLUSION

Giant OGMs can be safely and effectively removed using an endonasal, transcribriform approach.

How I do it: endonasal transcribriform approach for resection of esthesioneuroblastoma

BACKGROUND

Olfactory neuroblastoma, also known as esthesioneuroblastoma, accounts for only 3-6% of sinonasal malignancies but confers a 40% 5-year overall survival.

METHOD

The authors describe techniques for the endonasal, minimally invasive resection of an esthesioneuroblastoma in a 69-year-old man who presented with headaches and anosmia and describe surgical nuances and their effect on adjuvant therapy planning.

CONCLUSION

This approach, along with microsurgical techniques, helped increase tumor visualization, improved marginal resection, and reduced surgical risk, which may improve patient outcomes. Multilayered reconstruction with a synthetic dural substitute and creation of a nasoseptal flap were performed to reduce postoperative cerebrospinal fluid leak.

Treatment outcome of atypical EGFR mutations in the German National Network Genomic Medicine Lung Cancer (nNGM)

BACKGROUND

Atypical EGFR mutations occur in 10-30% of NSCLC patients with EGFR mutations and their sensitivity to classical EGFR-tyrosine kinase inhibitors (TKI) is highly heterogeneous. Patients harboring one group of uncommon, recurrent EGFR mutations (G719X, S768I, L861Q) respond to EGFR-TKI. Exon 20 insertions are mostly insensitive to EGFR-TKI but display sensitivity to exon 20 inhibitors. Clinical outcome data of patients with very rare point and compound mutations upon systemic treatments are still sparse to date.

PATIENTS AND METHODS

In this retrospective, multi-center study of the national Network Genomic Medicine (nNGM) in Germany, 856 NSCLC cases with atypical EGFR mutations including co-occuring mutations were reported from 12 centers. Clinical follow-up data after treatment with different EGFR-TKI, chemotherapy and immune checkpoint inhibitors were available from 260 patients. Response to treatment was analyzed in three major groups: (1) uncommon mutations (G719X, S7681, L861Q and combinations), (2) exon 20 insertions and (3) very rare EGFR mutations (very rare single point mutations, compound mutations, exon 18 deletions, exon 19 insertions).

RESULTS

Our study comprises the largest thus far reported real-world cohort of very rare EGFR single point and compound mutations treated with different systemic treatments. We validated higher efficacy of EGFR-TKI in comparison to chemotherapy in group 1 (uncommon), while most exon 20 insertions (group 2) were not EGFR-TKI responsive. In addition, we found TKI sensitivity of very rare point mutations (group 3) and of complex EGFR mutations containing exon 19 deletions or L858R mutations independent of the combination partner. Notably, treatment responses in group 3 (very rare) were highly heterogeneous. Co-occurring TP53 mutations exerted a non-significant trend for a detrimental effect on outcome in EGFR-TKI treated patients in groups 2 and 3 but not in group 1.

CONCLUSIONS

Based on our findings we propose a novel nNGM classification of uncommon EGFR mutations.

Surgical repair of nasal septal perforations: A systematic review and meta-analysis

BACKGROUND

A wide variety of techniques for the surgical repair of nasal septal perforations (NSPs) have been described. Surgical management of NSPs can be broadly divided into open versus endonasal approaches, with additional variables involving unilateral or bilateral flaps, use of grafts, and placement of splints. The objective of this study was to compare surgical approaches and their outcomes.

METHODS

PubMed, EMBASE, and CINAHL Plus databases were examined for patients undergoing NSP repair. English-language studies reporting surgical management of patients with the primary diagnosis of NSP were included. Outcome measures of interest included perforation size, surgical approach characteristics, and success rate defined as complete closure assessed by surgeon postoperatively. The quality of articles was assessed with the methodological index for nonrandomized studies (MINORS) criteria. A random-effects model was used to calculate pooled proportions for the different outcomes.

RESULTS

The electronic database search yielded 1076 abstracts for review. A total of 64 articles met the inclusion criteria, with 1591 patients: 1127 (71%) underwent an endonasal approach and 464 (29%) an open approach. The median (range) MINORS score was 10 (5-12) out of 16 points. Overall, 91% of patients had total closure (95% confidence interval [CI], 0.89-0.93, p < 0.01), with moderate heterogeneity between studies (I²  = 42.03%). There was no difference in closure success between open and endonasal approaches. Use of bilateral versus unilateral flaps, interposition grafts, and intranasal splints and packing were not associated with differences in outcomes.

CONCLUSION

Nasal septal perforation surgical repair success rates are comparable regardless of technique.

Development and validation of technologies suitable for the decontamination and re-use of contaminated N95 filtering facepiece respirators in response to the COVID-19 pandemic

Background

Coronavirus disease 2019 (COVID-19) has brought significant challenges to society globally, particularly in the area of healthcare provision. A pressing need existed in protecting those tasked with delivering healthcare solutions during the COVID-19 crisis by providing solutions for preserving adequate supplies of effective personal protective equipment (PPE).

Aim

To evaluate and validate available methods for the decontamination of N95 filtering facepiece respirators (FFRs) while maintaining functionality during re-use.

Methods

Multiple low-temperature steam and vaporized hydrogen peroxide (VHP) technologies were assessed for inactivation of Mycobacterium spp. and feline calicivirus (employed as representatives of the contamination challenge).

Findings

Virus (≥3log₁₀) and Mycobacterium spp. (≥6log₁₀) inactivation was achieved on various types of N95 FFRs using an array of heat (65–71^oC), humidity (>50% relative humidity) and VHP without affecting the performance of the PPE.

Conclusion

The methods have been validated and were authorized by the US Food and Drug Administration under a temporary emergency use authorization. Based on the findings, opportunities exist for development and deployment of decontamination methods made from simple, general purpose materials and equipment should a future need arise.

Non-invasive Fungal Sinusitis as a Complication of a Steroid-Eluting Stent Following Endoscopic Sinus Surgery: A Case Report

OBJECTIVE

Steroid eluting stents have proven to be a highly useful adjunctive therapy for chronic rhinosinusitis (CRS) and play an important role in the treatment of many inflammatory diseases of the sinuses. Few reports of adverse events were reported in clinical trials and are described in the literature. However, we describe the first known case of an immunocompetent patient developing non-invasive fungal tissue infection as a sequelae of stent-related tissue necrosis requiring surgical debridement.

METHODS

A 69-year-old immunocompetent male with CRS had Propel™ stents placed in the bilateral frontal sinus outflow tracts during revision endoscopic sinus surgery. He presented 2 weeks post-operatively with severe facial pain without vision changes, fevers, mental status changes, or evidence of cranial neuropathies. On rigid nasal endoscopy, necrotic tissue and gross fungal elements were visualized in the left frontal sinus outflow tract at the area of previous steroid stent position.

RESULTS

The patient was taken for urgent endoscopic sinus surgery and debridement given significant symptoms and concern for invasive fungal infection. A revision left maxillectomy, ethmoidectomy, and draf 2b frontal sinus drillout were performed, with healthy bleeding tissue encountered beneath necrotic tissue. Pathology revealed tissue necrosis, exudative lumenal debris, and extensive fungal elements with no evidence of tissue invasion, and cultures yielded growth of aspergillus niger. The patient's symptoms improved significantly on post-operative day 1, he had normal post-operative changes at 2 weeks following debridement, and had no recurrence of fungal infection with complete healing at 4 months.

CONCLUSION

While likely rare, steroid-eluting stents may pose a risk of saprophytic tissue infection as a result of tissue necrosis and local immunosuppression. Caution should be taken in using these devices in immunocompromised patients.

Factors driving olfactory loss in patients with chronic rhinosinusitis: a case control study

BACKGROUND

Olfactory dysfunction (OD) in chronic rhinosinusitis (CRS) is common. It is likely that numerous factors such as sex, race, age, allergies, asthma, smoking, and other comorbidities play a role in CRS-related OD. In order to determine which aspects of OD are due solely to CRS and which are associated with other confounders, control populations are needed to allow appropriate risk assessments.

METHODS

Prospective, multi-institutional enrollment of patients with CRS and control subjects without CRS was performed. Demographic information, comorbidities, and olfactory testing (Sniffin' Sticks) of threshold (T), discrimination (D), and identification (I) scores (TDI) was collected.

RESULTS

A total of 224 patients with CRS and 164 control subjects were enrolled. Olfaction was worse in CRS patients compared to controls (mean ± standard deviation (SD) TDI = 22.4 ± 9.5 vs 28.8 ± 7.0, respectively, p < 0.001). Only 27% of CRS patients were normosmic compared to 49% of controls (p < 0.001). When stratifying by nasal polyp (NP) status, CRSwNP patients had significant impairments in TDI, T, D, and I compared to controls with mean differences of 11.2, 3.3, 3.5, and 4.4 points, respectively (all p < 0.001). In contrast, CRSsNP patients only had impaired T when compared to controls with a mean difference of 2.2 points (p < 0.001). Multivariate modeling of TDI scoring showed that OD was driven by polyps, asthma, diabetes, and age. CRSsNP was not independently associated with worse TDI scores.

CONCLUSION

OD in CRS patients is multifactorial. Independent drivers appear to be polyp status, asthma, diabetes, and age. OD in patients with CRSsNP is similar to controls with the exception of impaired thresholds.

Pilot Investigation: Prospective Needs Assessment of Knowledge, Attitude, and Insight About Mental Health Treatment Options in Patients With Chronic Rhinosinusitis

INTRODUCTION

Mood disorders frequently coexist with chronic rhinosinusitis (CRS), yet patient views of how mental health impacts their disease, and their willingness to engage in treatment is not well understood.

METHODS

Subjects with CRS were enrolled regardless of their mental health status and completed a needs questionnaire on mental health as it related to CRS. In addition, demographic and disease-specific data were collected.

RESULTS

We enrolled 55 subjects. In addition, 29.1% of them had polyps, with mean endoscopy/computed tomography (CT)/Sino-Nasal Outcome Test (SNOT-22) scores of 3.9/9.7/41.2, respectively and 45% thought depression was common in CRS patients. In total, 78.2% were open to taking a depression screener and would be comfortable discussing mental health with their Ear Nose and Throat provider, 76.4% of patients felt that treating mental health problems could improve sinus-related quality of life (QOL), and 87.3% were open to meeting with a mental health professional or participating in a course on managing stress/anxiety/mental health issues. The multivariate regression model of whether patients felt that treating the mind would improve sinus-related QOL as predicted by age, gender, SNOT-22, CT scores, and endoscopy scores was statistically significant (P = .027) and explained 42% of the variance in answers, but only age and gender approached statistical significance (P = .06 and .04).

CONCLUSIONS

CRS patients acknowledged the high prevalence of comorbid mood disorders and were willing to discuss and be treated for mental health issues. Many patients felt that treating their mental health would improve their disease-specific QOL. These findings warrant further study of how to incorporate the management of metal health into CRS treatment algorithms.

Symptom importance, patient expectations, and satisfaction in chronic rhinosinusitis

BACKGROUND

Sinonasal symptoms and poor quality of life (QOL) prompt chronic rhinosinusitis (CRS) patients to undergo sinus surgery (ESS). However, little is known regarding the symptoms most important to patients and how these impact expectations and postoperative satisfaction.

METHODS

A prospective, multi-institutional cohort study of 100 CRS patients undergoing ESS completed a novel adaptation of the 22-item Sino-Nasal Outcome Test (SNOT-22) wherein they rated how important it was for specific symptoms to improve after surgery, along with preoperative expectations and postoperative satisfaction. The primary satisfaction measure was whether a patient would choose to undergo endoscopic sinus surgery (ESS) again. A multivariate, logistic regression model was built using demographics, objective measures, and the adapted SNOT-22 data. Spearman correlation analysis was also performed.

RESULTS

Nasal obstruction was rated as "extremely" or "very" important by 93% of patients, followed by smell/taste, thick nasal discharge, need to blow nose, postnasal discharge, and sleep symptoms (range, 61-72%). Symptoms like sadness and embarrassment were not considered important by preoperative patients (≤28%). In multivariate logistic regression, postoperative satisfaction depended on preoperative expectations being met and ESS improving their most important symptoms (odds rato, 19.6-27.5; p < 0.005). Postoperative satisfaction was not correlated with achieving a minimal clinically important difference, but it was correlated with magnitude of change in SNOT-22 (r = 0.35; p < 0.05).

CONCLUSIONS

Nasal, smell, and sleep-related symptoms were consdidered most important by this cohort. Meeting of preoperative expectations, improvement of the most important symptoms, and the magnitude of change in the SNOT-22 may drive postoperative satisfaction.

[Epidemiological Study of the Effects of Gender, Age, Mobility and Time of Injury on Proximal Femoral Fractures]

PURPOSE OF STUDY Based on the selected criteria the study presents the evaluation of data of patients who underwent a surgery for proximal femoral fracture at the Department of Orthopaedic Trauma of the 1 st Faculty of Medicine and Military University Hospital Prague in the period 2013-2016. The paper aimed to determine whether there are any differences in proximal femoral fractures depending on the selected criteria. MATERIAL AND METHODS The study comprised 805 patients (562 women and 243 men) older than 21 years with proximal femoral fractures who were treated between January 1, 2013 and December 31, 2016. In the study, the patient s data on gender, age, a type of fracture (according to the AO classification), a level of mobility, time of injury and month of injury were analysed. The data was evaluated using the methods of descriptive statistics, one-way analysis of variance, two-way analysis by ANOVA and by following select POST-HOC test (Fisher LSD test) were utilized, 95% confidence interval was selected . RESULTS In the group of treated patients, the men were outnumbered by women (70% vs. 30%). In women the fractures occurred at a significantly (p < 0.001) older age (82 years) compared to men (77 years). Until the 8 th decade the fractures in men dominated, while from the 9th decade the fractures were more frequent in women. A sharp increase in the number of fractures in women was reported exactly in the 9th decade (56% of the total number of fractures in women). The group of women showed a significant difference (p = 0.027) between the age of femoral neck fractures and the age of trochanteric femoral fractures (80 years vs. 84 years). In both genders intracapsular and pertrochanteric fractures prevailed. In women and men with a limited mobility, fractures were sustained at the highest mean age (85 years in women, 84 years in men) compared to the other levels of mobility. In mobile patients, a significant difference (p < 0.001) was found between the age of women and men at which the fracture was sustained (79 years vs. 71 years). The largest significant difference (p < 0.001) in the age of fracture is seen in night time (84 years in women, 71 years in men). The highest number of injuries was suffered in the months of October to January, whereas the lowest number was reported in the period from June to July. DISCUSSION The epidemiological studies underline a notably higher incidence of proximal femoral fractures in women than in men, which was also confirmed by our study. The mean age of women with proximal femoral fracture was significantly higher compared to men. Similar conclusions have been drawn also by other studies. The incidence of fractures in dependence on the age group was the highest in women and men in their 9th decade, which compared to the previous studies was at a later age. This finding can be justified by aging of the Czech population, with the growing number of persons in the 9 th decade age group between 2012 and 2017 by 40,000. Nonetheless, men prevailed in fractures until the 9 th decade, while from the 9 th decade there is a marked growth in the number of these fractures sustained by women. This corresponds with the findings of other authors. As to the individual types of fractures (neck, trochanteric fracture) no difference was revealed in the percentage of women and men. In both genders intracapsular and petrochanteric fractures prevailed. Neither the level of pre-fracture mobility, nor the time of injury have been sufficiently monitored and evaluated with regard to the age of patients, therefore there is no adequate data to compare our results with. The lowest mean age at the time of injury was achieved by fully mobile men (71 years), which can be attributable to their sports and social activities performed at this age. The highest number of proximal femoral fractures was reported in the period from October to January, whereas their lowest number was reported in the period from June to July, which corresponds with the majority of other conducted studies in this area of research. CONCLUSIONS A considerably higher incidence of proximal femoral fractures in women was confirmed. The mean age of women with proximal femoral fracture was significantly higher than in men (82 vs. 77 years). Men prevailed in the number of fractures up to the 9 th decade, whereas from the 9 th decade the number of proximal femoral fractures in women significantly grew. In individual types of fractures (neck, trochanteric fractures), no difference in percentage of women and men was found. In both the genders intracapsular and pertrochanteric fractures significantly prevailed. The lowest mean age (71 years) at the time of injury was achieved by fully mobile men. The same age was identified in men also with respect to injuries sustained at night. The highest number of proximal femoral fractures was reported in the period from October to January, the lowest in the period from June to July. The knowledge of these seasonal variations can help plan the health care in the medical facility concerned. Key words: proximal femur, fracture, gender, mobility, day-time, seasonality.

Surgeon and hospital cost variability for septoplasty and inferior turbinate reduction

BACKGROUND

Septoplasty and turbinate reduction (STR) is a common procedure for which cost reduction efforts may improve value. The purpose of this study was to identify sources of variation in medical facility and surgeon costs associated with STR, and whether these costs correlated with short-term complications.

METHODS

An observational cohort study was performed in a multifacility network using a standardized cost-accounting system to determine costs associated with adult STR from January 1, 2008 to July 31, 2015. A total of 4007 cases, performed at 21 facilities, by 72 different surgeons were included in the study. Total costs, variable costs, operating room (OR) time, and 30-day complications (eg, epistaxis) were compared among surgeons, facilities, and specialties.

RESULTS

Total procedure cost: (mean ± standard deviation [SD]) $2503 ± $790 (range, $852 to $10,559). Mean total variable cost: $1147 ± $423 (range, $400 to $5,081). Intersurgeon and interfacility variability was significant for total cost (p < 0.0001) and OR time (p < 0.0001). Intersurgeon OR supply cost variability was also significant (p < 0.0001). Otolaryngologists had less total cost (p < 0.0001), OR time/cost (p < 0.0001), and complications (p = 0.0164), but greater supply cost (p < 0.0001), than other specialties.

CONCLUSION

There is wide variation in cost associated with STR. Significant variance in OR time and supply cost between surgeons suggests these are potential areas for cost reduction. Although no increased 30-day complications were seen with faster and less costly surgeries, further research is needed to evaluate how time and cost relate to quality of care.

Hospital cost of pediatric patients with complicated acute sinusitis

OBJECTIVE

Review costs for pediatric patients with complicated acute sinusitis.

METHODS

A retrospective case series of patients in a pediatric hospital was created to determine hospital costs using a standardized activity-based accounting system for inpatient treatment between November 2010 and December 2014. Children less than 18 years of age who were admitted for complicated acute sinusitis were included in the study. Demographics, length of stay, type of complication and cost of care were determined for these patients.

RESULTS

The study included 64 patients with a mean age of 10 years. Orbital cellulitis (orbital/preseptal/postseptal cellulitis) accounted for 32.8% of patients, intracranial complications (epidural/subdural abscess, cavernous sinus thrombosis) for 29.7%, orbital abscesses (subperiosteal/intraorbital abscesses) for 25.0%, potts puffy tumor for 7.8%, and other (including facial abscess and dacryocystitis) for 4.7%. The average length of stay was 5.7 days. The mean cost per patient was $20,748. Inpatient floor costs (31%) and operating room costs (18%) were the two greatest expenditures. The major drivers in variation of cost between types of complications included pediatric intensive care unit stays and pharmacy costs.

CONCLUSION

Although complicated acute sinusitis in the pediatric population is rare, this study demonstrates a significant financial impact on the health care system. Identifying ways to reduce unnecessary costs for these visits would improve the value of care for these patients.

Nucleotide sequence of the clustered genes for apocytochrome b6 and subunit 4 of the cytochrome b/f complex in the spinach plastid chromosome

A 2.4 kilobase-pair segment of the spinach plastid chromosome carrying the genes for apocytochrome b6 and subunit 4 of the thylakoid membrane cytochrome b/f complex has been analysed by DNA sequencing and Northern blot analysis. The nucleotide sequence reveals two uninterrupted open reading frames of 211 and 139 triplets coding for two hydrophobic proteins of 23.7 kd (cytochrome b6) and 15.2 kd (subunit 4). The genes are located on the same strand and are separated from each other by 1018 untranslated base pairs. They map adjacent to the gene for the P680 chlorophyll α apoprotein of the photosystem II reaction center. The three genes appear to be under common transcriptional control and the transcripts post-transcriptionally modified. The deduced amino acid sequences of cytochrome b6 and subunit 4 both exhibit significant homology with published sequences from mitochondrial b cytochromes (42 kd) suggesting that these functionally equivalent polypeptides in photosynthetic and respiratory electron transport chains arose monophyletically.

Additional binding mechanism of palonosetron to the 5-HT3 receptor versus first generation 5-HT3 receptor antagonists

19583

Background: Palonosetron has a higher binding affinity and longer plasma half-life than first generation 5-HT3 receptor antagonists. Clinical trials have demonstrated that a single intravenous dose of palonosetron 0.25 mg provides better protection from chemotherapy-induced nausea and vomiting than other 5-HT3 receptor antagonists throughout the 5-day post-chemotherapy period. The purpose of this work is to determine differences in the molecular interactions of the antagonists with the receptor that could help explain the clinical efficacy differences. Methods: Molecular ligand-receptor relationships for commonly used 5-HT3 receptor antagonists were investigated. In particular, competitive vs. potential allosteric interactions between ondansetron, granisetron and palonosetron and the 5-HT3 receptor were examined. Binding experiments were carried out using each unlabeled antagonist in competition with [3H]-antagonist. Concentrations of [3H]-antagonists used in these experiments included the equilibrium dissociation constant (Ki) and several-fold Ki values in an effort to represent the probable concentrations of each antagonist at the receptor site in vivo. The inhibitory concentration of unlabeled antagonist needed to observe half maximal binding (IC50) as a function of [3H]-antagonist concentration was plotted for comparisons between ondansetron, granisetron and palonosetron. Results: A plot of the concentration of unlabeled antagonist needed to observe IC50 as a function of [3H]- antagonist concentration was linear when ondansetron and granisetron were in competition. On the other hand, when palonosetron was in competition with either granisetron or ondansetron the plot was curvilinear in each case. Conclusions: These results indicate that palonosetron exhibits both competitive and allosteric interactions with the 5-HT3 receptor, in contrast to ondansetron and granisetron which display strictly competitive antagonism. As allosteric interactions may induce changes in the receptor conformation, we can speculate that palonosetron's dual action on the 5-HT3-receptor could induce amplification of its inhibitory effect at the primary receptor binding site.

No significant financial relationships to disclose.

Interleukin-1beta stimulates growth hormone-releasing hormone receptor mRNA expression in the rat hypothalamus in vitro and in vivo

Changes in growth hormone-releasing hormone (GHRH), GHRH-receptor (R), somatostatin and interleukin (IL)-1beta mRNA levels were determined in fetal rat hypothalamic cultures after administration of IL-1beta (1, 10, 100 ng/ml, 2 h incubation), and in adult rat hypothalamus 5 h after intracerebroventricular injection of IL-1beta (2.5 and 25 ng). IL-1beta stimulated GHRH-R mRNA expression both in vitro (10 and 100 ng/ml) and in vivo (2.5 and 25 ng). Somatostatin mRNA was significantly stimulated and GHRH mRNA slightly reduced in vitro, while these mRNA species were not altered in vivo in response to IL-1beta. IL-1beta stimulated its own expression both in vitro (10 and 100 ng/ml) and in vivo (25 ng). IL-1beta-induced mRNA responses occurred 2 h after treatment in vitro (incubation times, 30 min to 6 h). IL-1beta also elicited slight GHRH releases in vitro. Up-regulation of hypothalamic GHRH-R by IL-1beta may explain previous findings suggesting that IL-1beta stimulates GHRH activity.

Sleep in mice with nonfunctional growth hormone-releasing hormone receptors

The role of the somatotropic axis in sleep regulation was studied by using the lit/lit mouse with nonfunctional growth hormone (GH)-releasing hormone (GHRH) receptors (GHRH-Rs) and control heterozygous C57BL/6J mice, which have a normal phenotype. During the light period, the lit/lit mice displayed significantly less spontaneous rapid eye movement sleep (REMS) and non-REMS (NREMS) than the controls. Intraperitoneal injection of GHRH (50 microg/kg) failed to promote sleep in the lit/lit mice, whereas it enhanced NREMS in the heterozygous mice. Subcutaneous infusion of GH replacement stimulated weight gain, increased the concentration of plasma insulin-like growth factor-1 (IGF-1), and normalized REMS, but failed to restore normal NREMS in the lit/lit mice. The NREMS response to a 4-h sleep deprivation was attenuated in the lit/lit mice. In control mice, intraperitoneal injection of ghrelin (400 microg/kg) elicited GH secretion and promoted NREMS, and intraperitoneal administration of the somatostatin analog octretotide (Oct, 200 microg/kg) inhibited sleep. In contrast, these responses were missing in the lit/lit mice. The results suggest that GH promotes REMS whereas GHRH stimulates NREMS via central GHRH-Rs and that GHRH is involved in the mediation of the sleep effects of ghrelin and somatostatin.

[Value of endoanal sonography in the assessment of faecal incontinence]

PURPOSE

The aim of this study was to assess the value of endoanal ultrasound (EUS) in comparison to anal manometry and operative findings in patients suffering from faecal incontinence. Patient history, localisation of sphincter defects and therapeutic modalities were analysed.

METHODS

Over a 3-years period, 92 patients with faecal incontinence were investigated by endoanal ultrasound. Results were compared with anal manometry in 81 cases.

RESULTS

At EUS, 27 patients (29 %) showed no sphincter defect, 18 (20 %) had an isolated internal sphincter defect, 13 (14 %) an isolated defect of the external sphincter and 34 (37 %) presented with a combined internal/external sphincter defect. Manometry correlated in 30 % with endoanal ultrasound. Compared with surgery, endoanal ultrasound was correct in 100 % and manometry in only 54 %. An obstetric trauma was most frequently related to faecal incontinence.

CONCLUSION

Endoanal ultrasound is a very sensitive method for localizing anal sphincter defects and is mandatory in the assessment of patients with faecal incontinence.

Influence of photoperiod on N-acetyltransferase activity and melatonin in the fiddler crab Uca pugilator

Melatonin and N-acetyltransferase (NAT) activity were measured in the eyestalks of fiddler crabs acclimated to various photoperiods: constant light, a L:D 12:12 h photoperiod, or constant dark. Following acclimation, eyestalks were collected every 3 h over a 24-h period; they were assayed for melatonin with a radioimmunoassay and for NAT activity with a radioenzymatic assay. In constant light, melatonin levels increased at 1300 h, from 142 to 431 pg x mg(-1) eyestalk; NAT activity increased concurrently, from 97 to 203 pmol x h(-1) x mg(-1) eyestalk, and both remained elevated until 0400 h. In the L:D 12:12 h photoperiod, melatonin levels increased at 1300 h from 28 to 230 pg x mg(-1) eyestalk, and though NAT activity increased significantly, from 80 to 122 pmol x h(-1) x mg(-1) eyestalk, an even greater increase occurred at 0400 h, when melatonin levels were low. In constant dark, melatonin levels increased at 1600 h, from 22 to 196 pg x mg(-1) eyestalk, with a concurrent increase in NAT activity from 93 to 140 pmol x mg(-1) x h(-1) eyestalk. However, the second peak in melatonin (111 pg x mg(-1)), occurring at 0400 h, was out of phase with the second peak of NAT activity (113 pmol x mg(-1) x h(-1) eyestalk) which occurred at 0700 h. NAT may be a rate-limiting step in melatonin synthesis in fiddler crabs under some conditions (constant light and the 1300 h peak in constant dark); however, NAT activity correlates poorly with melatonin levels in a L:D 12:12 h photoperiod and in constant dark relative to the 0400 h melatonin peak.

HIV test counselling at a tertiary hospital

A questionnaire was distributed to 64 of the 78 interns working at a teaching hospital in Cape Town in August 1992 to examine their attitudes and practice in respect of HIV test counselling. The questionnaire was completed by 61 interns. Thirteen per cent of those who responded counselled all patients, 49% counselled some patients and 38% counselled no patients. Thirty-four per cent stated that they felt that pre-test counselling was always necessary and 57% that post-test counselling was always necessary. The most frequently stated reasons for not counselling patients were language barriers, time constraints, feelings of incompetence on the part of the intern and the fact that the patient was too ill. It is recommended that standard counselling procedures be established in each ward and formal under- and postgraduate counselling training for medical students and interns be instituted.

Spinach plastid genes coding for initiation factor IF-1, ribosomal protein S11 and RNA polymerase alpha-subunit

The nucleotide sequence of 2.5 kbp from the cloned SalI fragments 8 and 11 of spinach plastid DNA has been determined. This region was found to encode three open reading frames for hydrophilic polypeptides of 77, 138, and 335 amino acids. Using the computer search algorithm of Lipman and Pearson (Science 227, 1435, 1985), these genes were identified as coding for homologues of E. coli initiation factor IF-1 (inFA), 30S ribosomal protein S11 (rps11), and the alpha-subunit of DNA-dependent RNA polymerase (rpoA). The spinach plastid gene organization is inFA - 381 bp spacer - rps11 - 72 bp spacer - rpoA. The genes are transcribed in vivo and appear to encode functional proteins. These findings imply that plastid chromosomes code for components of the organelle transcription apparatus.

Localization of the gene for apocytochromeb-559 on the plastid chromosome of spinach

The gene for cytochromeb-559, associated with the photosystem II reaction center, has been located on the spinach plastid chromosome by cell-free coupled transcription-translation and RNA-programmed hybrid selection translation using appropriate recombinant DNAs, RNA fractions, and monospecific antisera. The gene is located in the large single-copy segment of the plastid chromosome between the genes for cytochomef and the P680 chlorophylla apoprotein of photosystem II and transcribed in the opposite direction relative to these genes. The 10 kd protein is decoded from a bicistronic 1.0 kb mRNA and is apparently not made as a precursor in cell-free rabbit reticulocyte andE. coli lysates.

Localization of the genes for the two chlorophyll a -conjugated polypeptides (mol. wt. 51 and 44 kd) of the photosystem II reaction center on the spinach plastid chromosome

A core particle of the water-oxidizing photosystem II reaction center has been prepared from stacked spinach thylakoid membranes by a procedure involving extraction with the non-ionic detergent dodecyl-beta-D-maltoside and centrifugation in sucrose gradients. The protein-pigment complex consists of at least four polypeptide species: two components with mol. wts. of 51 and 44 kd which are conjugated with chlorophyll a and beta-carotene, the herbicide-binding protein of mol. wt. 32 kd and cytochrome b 559 (11 kd). The genes for the 51-and 44-kd polypeptides have been located on the circular 150-kbp spinach plastid chromosome. They were identified by hybrid-selection mapping, in vitro transcription-translation of recombinant DNAs and specific antisera which were used to characterize the translation products. The plastid chromosome carries one uninterrupted copy for each of these genes in its large single-copy region. The gene for the 51-kd protein (which probably bears the P(680) reaction center chlorophyll a) is located in close proximity to the gene for cytochrome b6, and some 70 kbp away from the gene for the ;32-kd' herbicide-binding protein of the reducing side of photosystem II. The gene for the 44-kd protein is situated halfway between these two genes adjacent to the gene for the P(700) chlorophyll a apoprotein of the photosystem I reaction center. Both photosystem II genes are transcribed into discrete RNA species in the same direction but from the opposite strand as the gene for the ;32-kd' protein.

Genes and transcripts for the polypeptides of the cytochrome b6/f complex from spinach thylakoid membranes

Cytochrome b6/f complex was prepared from washed thylakoid membranes by a procedure involving detergent treatment and centrifugation in sucrose gradients. The complex is composed of at least four polypeptide species, cytochrome f which occurs in two variant forms (mol. wt. 34/33 kd), cytochrome b6 (23 kd), the high-potential Rieske iron-sulfur protein (19 kd) and a fourth subunit (17 kd) of unknown function. Transcripts for the cytochromes f, b6 and subunit 4 were found in plastid RNA, those for the Rieske iron-sulfur protein in cytosolic poly(A) RNA. Transcripts for cytochrome b6 and subunit 4 are translated in rabbit reticulocyte lysates into products of correct length. The Rieske iron-sulfur protein and the cytochrome f apoprotein appear to be made as precursors with excess sequences of 7 and 4 kd, respectively. Cytochrome f, cytochrome b6 and subunit 4 are encoded by uninterrupted plastid genes that are located in the large single-copy region of the circular DNA molecule. Each of these genes is present once per chromosome. Their location and direction of transcription have been determined by hybrid-selection mapping and by cell-free transcription/translation of various recombinant DNAs. The genes for cytochrome b6 and for subunit 4 lie near each other, but do not overlap. They are transcribed into a single message. The gene for cytochrome f maps 15 kbp away from this cluster, close to the 3' end of the gene for the large subunit of ribulosebisphosphate carboxylase/oxygenase, and is transcribed into a separate 4 kb long RNA. All these genes have the same polarities with respect to each other.

Genes and transcripts for the P700 chlorophylla apoprotein and subunit 2 of the photosystem I reaction center complex from spinach thylakoid membranes

A photosystem I reaction center complex has been purified to homogeneity by a procedure involving partial solubilization of spinach thylakoid membranes, ion exchange chromatography and centrifugation in sucrose gradients. The complex contains 7 polypeptides: the P700 chlorophylla apoprotein with an apparent molecular weight of 67 kd, which at high resolution splits into two bands, and smaller polypeptides of 22 (subunit 2), 18.5, 18, 16, 12 and 10 kd.Stable transcripts for the P700 chlorophylla apojprotein and subunit 2 were found in plastid and cytosolic RNA, respectively. The apoprotein product obtained by translation in a mRNA-dependent cell-free rabbit reticulocyte lysate and also by DNA-programmed transcription-translation of cloned plastid DNA fragments inE. coli lysates was indistinguishable immunologically and electrophoretically from the authentic protein. However, the product immunologically related to subunit 2 was 4 kd larger than the mature compound indicating that this protein is encoded in the nucleus and synthesized as a precursor.The gene for the P700 chlorophylla apoprotein has been physically mapped on the spinach plastid chromosome by hybrid selection mapping and DNA-programmed cell-free transcription-translation using cloned restriction fragments of plastid DNA. There is one gene copy per chromosome and it is located centrally in the large single-copy region of the circular DNA molecule. This gene is uninterrupted and is transcribed in the same direction as that of the large subunit of ribulose bisphosphate carboxylase/oxygenase. Its transcript is approximately 4 kb longer than the 2 kbp structural gene.