WHO informal consultation on revision of guidelines on evaluation of similar biotherapeutic products, virtual meeting, 30 June – 2 July 2021

The WHO informal consultation was held to promote the revision of WHO guidelines on evaluation of similar biotherapeutic products (SBPs) adopted by the Expert Committee on Biological Standardization (ECBS) in 2009. It was agreed in the past consultations that the evaluation principles in the guidelines are still valid, but a review was recommended to provide more clarity and case-by-case flexibility. The opportunity was therefore taken to review the experience and identify areas where the current guidance could be more permissive without compromising its basic principles, and where additional explanation could be provided regarding the possibility of reducing the amount of data needed for regulatory approval. The meeting participants applauded the leading role taken by the WHO in providing a much-needed streamlined approach for development and evaluation of SBPs which will provide efficient and cost-effective product development and increase patient access to treatments. It was recognized that the principles as currently described in the draft WHO guidelines are based on sound science and experience gained over the last fifteen years of biosimilar approvals. However, since these guidelines when finalised will constitute the global standard for biosimilar evaluation and assist national regulatory authorities in establishing revised guidance and regulatory practice in this complex area, it was felt that further revision and clarity on certain perspectives in specific areas was necessary to dispel uncertainties arising in the current revised version. This report describes the principles in the draft guidelines, including topics discussed and consensus reached.

•

WHO guidelines serve as a basis for the development of national regulatory framework for biosimilars.

•

Revision of guidelines is to provide more flexibility and clarification on data required for regulatory approval.

•

Revised guidelines would contribute to improving consistency on regulatory decision and patient access to treatments.

Lung microbiome of stable and exacerbated COPD patients in Tshwane, South Africa

Chronic obstructive pulmonary disease (COPD) is characterised by the occurrence of exacerbations triggered by infections. The aim of this study was to determine the composition of the lung microbiome and lung virome in patients with COPD in an African setting and to compare their composition between the stable and exacerbated states. Twenty-four adult COPD patients were recruited from three hospitals. Sputum was collected and bacterial DNA was extracted. Targeted metagenomics was performed to determine the microbiome composition. Viral DNA and RNA were extracted from selected samples followed by cDNA conversion. Shotgun metagenomics sequencing was performed on pooled DNA and RNA. The most abundant phyla across all samples were Firmicutes and Proteobacteria. The following genera were most prevalent: Haemophilus and Streptococcus. There were no considerable differences for alpha and beta diversity measures between the disease states. However, a difference in the abundances between disease states was observed for: (i) Serratia (3% lower abundance in exacerbated state), (ii) Granulicatella (2.2% higher abundance in exacerbated state), (iii) Haemophilus (5.7% higher abundance in exacerbated state) and (iv) Veillonella (2.5% higher abundance in exacerbated state). Virome analysis showed a high abundance of the BeAn 58058 virus, a member of the Poxviridae family, in all six samples (90% to 94%). This study is among the first to report lung microbiome composition in COPD patients from Africa. In this small sample set, no differences in alpha or beta diversity between stable and exacerbated disease state was observed, but an unexpectedly high frequency of BeAn 58058 virus was observed. These observations highlight the need for further research of the lung microbiome of COPD patients in African settings.

Performance of image guided navigation in laparoscopic liver surgery - A systematic review

BACKGROUND

Compared to open surgery, minimally invasive liver resection has improved short term outcomes. It is however technically more challenging. Navigated image guidance systems (IGS) are being developed to overcome these challenges. The aim of this systematic review is to provide an overview of their current capabilities and limitations.

METHODS

Medline, Embase and Cochrane databases were searched using free text terms and corresponding controlled vocabulary. Titles and abstracts of retrieved articles were screened for inclusion criteria. Due to the heterogeneity of the retrieved data it was not possible to conduct a meta-analysis. Therefore results are presented in tabulated and narrative format.

RESULTS

Out of 2015 articles, 17 pre-clinical and 33 clinical papers met inclusion criteria. Data from 24 articles that reported on accuracy indicates that in recent years navigation accuracy has been in the range of 8-15 mm. Due to discrepancies in evaluation methods it is difficult to compare accuracy metrics between different systems. Surgeon feedback suggests that current state of the art IGS may be useful as a supplementary navigation tool, especially in small liver lesions that are difficult to locate. They are however not able to reliably localise all relevant anatomical structures. Only one article investigated IGS impact on clinical outcomes.

CONCLUSIONS

Further improvements in navigation accuracy are needed to enable reliable visualisation of tumour margins with the precision required for oncological resections. To enhance comparability between different IGS it is crucial to find a consensus on the assessment of navigation accuracy as a minimum reporting standard.

Comparison of manual and semi-automatic registration in augmented reality image-guided liver surgery: a clinical feasibility study

BACKGROUND

The laparoscopic approach to liver resection may reduce morbidity and hospital stay. However, uptake has been slow due to concerns about patient safety and oncological radicality. Image guidance systems may improve patient safety by enabling 3D visualisation of critical intra- and extrahepatic structures. Current systems suffer from non-intuitive visualisation and a complicated setup process. A novel image guidance system (SmartLiver), offering augmented reality visualisation and semi-automatic registration has been developed to address these issues. A clinical feasibility study evaluated the performance and usability of SmartLiver with either manual or semi-automatic registration.

METHODS

Intraoperative image guidance data were recorded and analysed in patients undergoing laparoscopic liver resection or cancer staging. Stereoscopic surface reconstruction and iterative closest point matching facilitated semi-automatic registration. The primary endpoint was defined as successful registration as determined by the operating surgeon. Secondary endpoints were system usability as assessed by a surgeon questionnaire and comparison of manual vs. semi-automatic registration accuracy. Since SmartLiver is still in development no attempt was made to evaluate its impact on perioperative outcomes.

RESULTS

The primary endpoint was achieved in 16 out of 18 patients. Initially semi-automatic registration failed because the IGS could not distinguish the liver surface from surrounding structures. Implementation of a deep learning algorithm enabled the IGS to overcome this issue and facilitate semi-automatic registration. Mean registration accuracy was 10.9 ± 4.2 mm (manual) vs. 13.9 ± 4.4 mm (semi-automatic) (Mean difference - 3 mm; p = 0.158). Surgeon feedback was positive about IGS handling and improved intraoperative orientation but also highlighted the need for a simpler setup process and better integration with laparoscopic ultrasound.

CONCLUSION

The technical feasibility of using SmartLiver intraoperatively has been demonstrated. With further improvements semi-automatic registration may enhance user friendliness and workflow of SmartLiver. Manual and semi-automatic registration accuracy were comparable but evaluation on a larger patient cohort is required to confirm these findings.

P1817Assessment of carotid stiffness indices in patients with ischemic stroke

Background

Arterial stiffness is considered as an emerging new important risk factor for stoke development. Measuring carotid stiffness is easy and non-invasive and thus can be widely applicable.

Purpose

To evaluate the carotid stiffness indices in patients with ischemic stroke compared to normal healthy subjects.

Methods

Included in this study are 60 patients (group 1) with ischemic stroke and 60 healthy control subjects (group 2). Participants were exposed to routine clinical examination and Duplex assessment of both carotid arteries. A specific wall tracking system was used for the semiautomatic calculation of the carotid stiffness indices, which included; compliance coefficient (CC), distensibility coefficient (DC), carotid pulse wave velocity (PWV) and carotid intima media thickness (IMT). Results from both carotid arteries were averaged and data from group 1 patients were compared to group 2 subjects.

Results

The mean age was (60.1±6.9 years) in group 1 compared to (60.1±6.6 years) in group 2 (p=0.9). A significant difference was found between both groups in all carotid stiffness indices; including average CC (0.64±0.29 vs 0.82±0.36 m2/kpa, p=0.004); average DC (11.69±5.42 vs 18.61±11.87 1/kpa, p<0.001); average PWV (16.5±0.6 vs 12.5±3.7 m/s, p<0.001) and average IMT (0.78±0.13 vs 0.68±0.18 mm, p=0.001). Only the carotid PWV was found to be a predictor of vascular stroke (p=0.001)

Conclusion

Patients with vascular stroke have higher carotid stiffness indices than age matched control subjects. Measuring carotid stiffness indices in patients who have atherosclerotic risk factors may help predict those at risk of vascular stroke and thus guide a tighter and a more efficient risk factors control.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Incidence of bladder cancer in a one-stop clinic

OBJECTIVE

The aim of this study is to demonstrate the importance of transvaginal scan (TVS) in the detection of bladder tumors in patients presenting with postmenopausal bleeding.

MATERIALS AND METHODS

We examined the case records of all patients that attended a one-stop clinic between September 2001 and May 2004. Those presenting with postmenopausal bleeding (PMB) underwent transvaginal scan and endometrial pipelle sampling. Where bladder pathology was detected, urine cytology was done before referral to the urologist.

RESULTS

In all, 753 women were referred. There were 17 cases of endometrial cancer detected. Three cases of bladder tumor (malignant transitional cell cancer) were found.

CONCLUSION

We recommend careful assessment of all pelvic organs in women presenting with PMB.

Effect of the quality of water used for dialysis on the efficacy of hemodialysis: a single-center experience from Morocco

The quality of the water used for dialysis has been suggested as a factor causing inflammation in patients on hemodialysis (HD). We therefore conducted this study to identify the effect of quality of the water on nutritional state, inflammation and need for human recombinant erythropoietin (EPO) in patients undergoing HD at Agadir, Morocco. This prospective study included patients on HD for at least one year. The water treatment was done according to the standard protocol, which was followed by additional enhancement of ultrafiltration using an additional polysulfone filter (diasafe, Fresenius, Bad Homburg, Germany) before the dialyser. Water was monitored regularly during the study period to ensure acceptable levels of bacterial count as well as endotoxin levels. Various parameters including dry weight, systolic and diastolic blood pressure (PA) before and after an HD session, need for human recombinant EPO, levels of hemoglobin (Hb), albumin, ferritin, C-reactive protein (CRP), and the dose of dialysis delivered (Kt/V) were measured first at the beginning of the study and thereafter, in the third, sixth and 12 th months of the study. The study involved 47 patients, and after 12 months of the study, an improvement in median dry weight (1.2 kg, P = 0017) and a simultaneous median reduction of 20.7 IU/kg/week of EPO, with an in-crease of the median level of Hb, was noted. The results of our study suggest that by improving the biocompatibility of HD with the use of good quality water, patients acquire a better nutritional, inflammatory and hematologic status.

Multitargeted approach using antisense oligonucleotides for the treatment of asthma

Asthma is characterized by inflammation and hyperresponsiveness related to the accumulation of inflammatory cells, particularly eosinophils, within the airways. We tested the hypothesis that a multitargeted approach is better than a single-targeted approach in a rat model of asthma. We simultaneously delivered oligonucleotides (ODNs) targeting the chemokine receptor CCR3 and the common beta chain subunit of the receptors for IL-3, IL-5, and GM-CSF at the time of ovalbumin challenge in sensitized Brown Norway rats. Fewer eosinophils were detected in bronchoalveolar lavage (BAL) of rats treated with both ODNs as compared to each ODN alone. Moreover, airway responsiveness to LTD(4) was significantly decreased at lower doses in the 2 ODN-treated groups compared to a single ODN. As ODN therapy has raised concerns of toxicity we therefore examined ODNs prepared with modified DNA bases, specifically 2'amino, 2'deoxyadenosine (DAP) in place of adenosine. In vivo, administration of individual DAP-ODN was efficacious in inhibiting airway hyperresponsiveness, whereas delivery of 2 DAP-ODNs (targeting CCR3 and common beta chain) reduced the influx not only of eosinophils but also lymphocytes and macrophages in the lungs of rats as compared to the unmodified ODNs. Blocking multiple inflammatory pathways simultaneously is more effective in preventing eosinophilia and airway hyperresponsiveness than inhibiting either pathway alone. The challenges associated with the development of a product containing two oligonucleotides in humans are discussed.

Large loop excision and cold coagulation for management of cervical intraepithelial neoplasia

OBJECTIVES

To evaluate the efficacy of large loop excision of the transformation zone (LLETZ) combined with a single application of the cone probe of a Semm Cold Coagulator as a new treatment for women with cervical intraepithelial neoplasia (CIN).

METHODS

Retrospective case-record review of 666 women treated with large loop excision and cold coagulation (LLECC) from 1992 to 2000.

RESULTS

Of the women who had high-grade CIN at their initial consultation, 4.2% had abnormal cytologic results 6 months after treatment and 0.6% had abnormal cytologic results at 12 months. Of the women who had low-grade CIN at initial presentation, 3.8% had abnormal cytologic results 6 months after treatment and none (0%) at 12 months. Furthermore, there were no reported cases of cervical cancer in this cohort of women during the follow-up period. Short-term bleeding complications (within 24 h of the procedure) occurred in 1% of the women assessed.

CONCLUSIONS

Large loop excision combined with cold coagulation is a new and effective treatment for CIN. Randomized controlled trials are required to confirm these findings and determine the long-term safety of the technique.

Inhibition of GM-CSF/IL-3/IL-5 signaling by antisense oligodeoxynucleotides targeting the common beta chain of their receptors

Granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 play a key role in allergic inflammation. They mediate their effect via receptors that consist of two distinct subunits, a cytokine-specific alpha subunit and a common beta subunit (betac) that transduces cell signaling. We sought to down-regulate the biologic activities of GM-CSF, IL-3, and IL-5 simultaneously by inhibiting betac mRNA expression with antisense technology. Experiments were performed with TF-1 cells (a human erythroleukemia cell line expressing GM-CSF, IL-3, and IL-5 receptors, which proliferates in response to these cytokines), monocytic U937 cells, which require these cytokines for differentiation, and purified human eosinophils. Cells were treated with antisense phosphorothioate oligodeoxynucleotides (ODN) targeting betac mRNA. In contrast to nontreated cells and cells treated by sense or mismatched ODN, antisense ODN inhibited betac mRNA expression and significantly decreased the level of cell surface betac protein expression on TF-1 and U937 cells. Receptor function was also affected. Antisense ODN were able to inhibit TF-1 cell proliferation in vitro in the presence of GM-CSF, IL-3, or IL-5 in the culture medium and eosinophil survival. We suggest that antisense ODN against betac may provide a new therapeutic alternative for the treatment of neoplastic or allergic diseases associated with eosinophilic inflammation.

A three-trocar midline approach to laparoscopic-assisted colectomy

Several techniques have been described for the trocar placement in laparoscopic-assisted colectomy (LAC). They share the placement of four or five trocars in different areas of the abdomen. A specimen extraction incision in these techniques generally incorporates only one or two trocar sites, and combined length of these incisions approximates the length of a limited laparotomy incision for open colectomy. In addition, intracorporeal communication between the surgeon and the first assistant, who usually works "against" the camera, is challenging and may actually prolong the procedure. We describe here a three-trocar midline approach to laparoscopic-assisted colectomy that allows incorporation of these trocar sites into a midline laparotomy approximately 3 inches long for "open" bowel resection and anastomosis. As a result, the total length of the abdominal wall incision is smaller and cosmesis is superior, while the relative simplicity of the technique, in comparison to complete laparoscopic colectomy, is emphasized. In this technique, the surgeon is much less dependent on the assistant's laparoscopic skills, allowing the laparoscopic part of the procedure to be performed by one surgeon assisted only by a camera operator.

Cholera toxin triggers apoptosis in human lung cancer cell lines

Cholera toxin (ChT) inhibits signals generated by multiple growth factors in human lung cancer cells, resulting in cell growth inhibition. We now report that ChT triggers apoptosis as shown by DNA fragmentation and activation of caspases cleaving poly(ADP-ribose) polymerase and lamin B. Apoptosis induced by ChT in a small cell lung cancer cell line is not affected by manipulations of intracellular cAMP through preincubation with isobutylmethylxanthine but can be modestly increased through inhibition of protein kinase C with chelerythrine. Thus, apoptosis is actively suppressed in lung cancer cells by a ChT-sensitive-growth regulatory pathway, and these observations may have significant implications in the development of novel strategies for lung cancer treatment.

Laparoscopic treatment of gastric volvulus: a case report

A case report of laparoscopic treatment of gastric volvulus in an 85-year-old man is presented. The patient did not have intraoperative or postoperative complications, tolerated a diet in 48 hours, and was discharged home 4 days after surgery. A gastric volvulus can be safely treated using laparoscopic techniques.

Laparoscopic-assisted repair of extensive rectosigmoid injury after colonoscopy

Treatment of colonic injury has progressed since the recognition of the value of colostomy or bowel exteriorization during the second World War. The treatment guidelines take into consideration the time interval between perforation and treatment as well as the nature, the site, and the cause of perforation. Laparoscopic primary repair of relatively small colonic perforations without spillage of bowel content has been reported. Extensive large bowel injury with appreciable colonic spillage usually requires a laparotomy and diversion. We report a case of a 57-year-old woman who presented with extensive rectosigmoid injury and colonic spillage after colonoscopy and was treated using laparoscopic assistance.

Laparoscopic-assisted abdominoperineal proctosigmoidectomy for rectal prolapse. A new technique

The inability to completely mobilize the redundant colon in perineal rectosigmoidectomy (Altemeier's procedure) for full-thickness rectal prolapse is a main contributor to the recurrence rate associated with the procedure. However, the presence of a redundant sigmoid after the Ripstein procedure or other rectal sling operations is the main cause of the high rate of postoperative constipation and stool impaction. Low anterior resection as the definitive treatment is associated with the higher morbidity of laparotomy and the risk of anastomotic leak. We describe a laparoscopic-assisted surgical approach which combines the benefits of completely resecting the redundant sigmoid colon as well as the performance of extraperitoneal anastomosis at the level of the anus.

Deleterious effects of khat addiction on semen parameters and sperm ultrastructure

The semen parameters and sperm ultrastructural morphology have been described in semen samples from two groups of Yemeni subjects. The first 'exposed' group comprised 65 khat addicts, while the second control group included 50 non-khat addict subjects. The mean age was 39.94 +/- 13.85 and 35.72 +/- 11.35 years in the exposed and control groups respectively, without a significant difference. The mean duration of khat addiction among the addicts was 25.34 +/- 12.96 years (range 6.00-48.00). Statistically significant differences were detected between the semen parameters of the two groups. Such parameters, including semen volume, sperm count, sperm motility, motility index and percentage of normal spermatozoa, were lower among addicts. Significant negative correlation was also found between the duration of khat consumption and all semen parameters (r ranged from -0.30 to -0.74). At the transmission electron microscopy level, a counting system was incorporated to compare the numbers of normal spermatozoa with deformed and dead spermatozoa in ultrathin plastic sections. The total mean percentage of deformed spermatozoa was approximately 65%. Different patterns of sperm deformation were demonstrated, and included both the head and flagella in complete spermatozoa, aflagellate heads, headless flagella and multiple heads and flagella. Deformed heads showed aberrated nuclei with immature nuclear chromatin and polymorphic intranuclear inclusions; these were associated with acrosomal defects. The deformed flagella demonstrated numeric aberrations of the axonemal 9 + 2 configuration and structural defects of their associated elements. Persistent cytoplasmic droplets were observed frequently. This study has shown for the first time the deleterious effects of khat addiction on semen parameters in general and sperm morphology in particular of all addicts, especially those who have consumed khat for longer periods of time.

Rhabdomyolysis and acute renal failure in head injury patients

Rhabdomyolysis is a known complication of crush injuries, but is not known to complicate the course of the patients with head injuries without other apparent skeletal muscle injuries. The frequency of renal failure may be high in such group of patients. We conducted a prospective study to evaluate such incidence on twenty patients with head injuries. Ten patients (50%) had other injuries in addition, but none of the patients had crush injury. All the patients were investigated daily for serum electrolytes, urea, creatinine, creatinine phosphokinase (CPK) and myoglobulinuria. All these patients were on a dehydrating protocol to prevent brain edema, including administration of dopamine infusion (1-3 microg/kg/min), intravenous bolus doses of mannitol, and sodium bicarbonate. Nine patients (45%) developed renal impairment, three of them had no other apparent skeletal muscle injuries, but none of them required dialysis. Rhabdomyolysis is not uncommon in head injury patients in the absence of apparent skeletal muscle injuries, and may precipitate renal failure. This may have therapeutic implications to prevent the incidence of acute renal failure in such group of patients.

Prevalence of hepatitis C virus antibodies in hemodialysis patients in madinah Al munawarah

This study was carried out to evaluate the prevalence of antibodies against hepatitis C virus (HCV) in our hemodialysis (HD) unit at Madinah Al Munawarah in Saudi Arabia. Fifty six of the 94 patients (60%) studied were positive for HCV, while none of the thirty staff members working in the same unit were positive. The positivity of HCV correlated significantly with duration on HD. No significant correlation was found with the number of blood transfusions, hepatitis B markers or liver enzymes.

Inhibition of calcium release from the sarcoplasmic reticulum of rabbit aorta by hydralazine

1. The mechanism of hydralazine-induced vasorelaxation was investigated in rabbit isolated aorta, by determining its ability to interfere with force development under a variety of conditions. 2. Hydralazine relaxed phenylephrine-contracted aorta with half maximal relaxation at 17 microM and maximal relaxation above 100 microM. At 200 microM, hydralazine had little effect on contractions induced by 25 mM or 50 mM K+. 3. Hydralazine was equally effective at inhibiting contractile responses to phenylephrine in the absence or presence of extracellular Ca2+. Responses to phenylephrine in Ca(2+)-free solution were blocked to the same degree whether hydralazine was applied during filling of the sarcoplasmic reticulum (SR) Ca2+ stores or after filling was complete. Caffeine-induced contractions were less sensitive to block by hydralazine. 4. Thapsigargin, cyclopiazonic acid, ryanodine, nifedipine and diltiazem all failed to block the inhibitory effect of hydralazine on tonic contractions to phenylephrine in the presence of extracellular Ca2+. However, when cyclopiazonic acid was applied either with diltiazem or ryanodine, substantial inhibition of the hydralazine response was observed. 5. We propose that tonic contractions to phenylephrine are largely maintained by Ca2+ cycling through the SR, with Ca2+ entering the smooth muscle cell being sequestered by the SR eventually to leak out through IP3-activated channels close to the contractile proteins. Sequestration of Ca2+ would employ two pathways, one sensitive to inhibitors of the SR Ca(2+)-ATPase and the other to Ca antagonists. We further suggest that, in the presence of extracellular Ca2+ and phenylephrine, the leakage of Ca2+through IP3-activated channels is significantly reduced only if both routes for SR Ca2+ accumulation are blocked or the Ca2+-ATPase is blocked while the SR is made leaky with ryanodine.6. We conclude that the main action of hydralazine is to block the IP3-dependent release of Ca2+ from the sarcoplasmic reticulum. Thus conditions that diminish the contribution of IP3-induced Ca2+ release to tension can inhibit the hydralazine-induced vasorelaxation.

Neurobehavioral changes among workers in some chemical industries in Egypt

This study investigates the long-term neuropsychiatric manifestations of single or combined chemicals: manganese; zinc phosphide; lead, mercury, and TNT; and pesticides among exposed industrial workers. We found that 75% of the exposed subjects as a whole and 50% of those exposed to each of Zinc phosphide and pesticides presented with more than one neuropsychiatric symptoms or signs. The main signs were mask faces, hyporeflexia, hyperreflexia, peripheral neuropathy, static tremors, radiculopathy, muscle weakness, mental changes, fasciculations and tremors, wasting, hypotonia, abnormal deep reflexes, and sensory hyposthesia. Neurological manifestations were confirmed by electromyography and their severity was related to the duration of exposure and confirmed as well by electroencephalography. These results are discussed and their implications high-lighted.

Platelet-derived growth factor AA and AB dimers are present in normal human epithelial lining fluid

Normal lung architecture is related to the presence of mesenchymal cells (fibroblasts and smooth muscle cells), and to the production by these cells of extracellular matrix. The turnover of mesenchymal cells is under a fine regulation due, at least in part, to the local presence of different mediators acting on their cell cycle. Since normal human alveolar macrophages obtained by bronchoalveolar lavage (BAL) spontaneously release platelet-derived growth factor (PDGF), a cytokine with chemotactic and growth activity on mesenchymal cells, we evaluated normal human epithelial lining fluid (ELF) for the presence of PDGF. Active only as a dimer, PDGF is a glycoprotein composed of two chains (A and B) and, thus, can be present in three forms: AA, AB, and BB dimers. Interestingly, normal ELF contains PDGF AA dimers, and to a lesser extent AB dimers, while no significant level of BB dimers is detected. Furthermore, ELF PDGF is biologically active and responsible for a significant part of the chemotactic activity and the "competence" growth activity for mesenchymal cells present in normal ELF. These findings suggest that ELF PDGF has a role in normal lung structure maintenance and tissue repair.

Platelet-derived growth factor AA and AB dimers are present in normal human epithelial lining fluid

Normal lung architecture is related to the presence of mesenchymal cells (fibroblasts and smooth muscle cells), and to the production by these cells of extracellular matrix. The turnover of mesenchymal cells is under a fine regulation due, at least in part, to the local presence of different mediators acting on their cell cycle. Since normal human alveolar macrophages obtained by bronchoalveolar lavage (BAL) spontaneously release platelet-derived growth factor (PDGF), a cytokine with chemotactic and growth activity on mesenchymal cells, we evaluated normal human epithelial lining fluid (ELF) for the presence of PDGF. Active only as a dimer, PDGF is a glycoprotein composed of two chains (A and B) and, thus, can be present in three forms: AA, AB, and BB dimers. Interestingly, normal ELF contains PDGF AA dimers, and to a lesser extent AB dimers, while no significant level of BB dimers is detected. Furthermore, ELF PDGF is biologically active and responsible for a significant part of the chemotactic activity and the "competence" growth activity for mesenchymal cells present in normal ELF. These findings suggest that ELF PDGF has a role in normal lung structure maintenance and tissue repair.

Differential expression of PDGF A- and B-chain genes and production of AA and AB dimers by activated human blood monocytes

Platelet-derived growth factor (PDGF) is composed of two chains (A and B) bound by disulfide bridges. Blood monocytes (BM) express the c-sis proto-oncogene, the gene coding for PDGF B-chain, and release PDGF. To evaluate PDGF release and A- and B-chain gene expression by BM, normal BM were cultured with LPS and specific transcripts for PDGF A- and B-chain genes were detected by Northern analysis and PDGF dimers by specific Elisas. Normal BM did not spontaneously express either A- or B-chain gene while, when activated, PDGF B-chain expression was precocious (maximum at 1 h) and decreased over 24 h; PDGF A-chain transcripts were present after 4 h and progressively increased over 24 h. Furthermore, activated BM released more AB dimers than AA dimers and almost no BB dimers. This observation confirms the concept of PDGF A- and B-chain separate gene regulation, and defines the specific molecular pattern of PDGF released by activated BM.

Effect of acute and chronic moderate hypoxia on the kinetics of lidocaine and its metabolites and on regional blood flow

The effect of acute and chronic hypoxia on the disposition of lidocaine and its metabolites, and on regional blood flow has been examined in conscious beagles (n = 5). Each dog received an infusion of lidocaine for 5 h under three experimental conditions: (1) breathing air; (2) following acute exposure to a FIO2 of 8% and a FICO2 of 3.5% to generate a PaO2 of 45 mmHg without hypocapnia; and (3) after 6 days of hypoxemia. Multiple blood samples were drawn to assess the kinetics of lidocaine and its metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX). Three hours after the end of the infusion of lidocaine, the dogs received radioactive microspheres to estimate hepatic, renal and brain blood flow. Neither acute nor chronic moderate hypoxia affected the kinetics of lidocaine, the parent compound. However, both experimental conditions increased plasma concentrations of MEGX and GX and increased the ratio of the area under their plasma concentration curves to the dose of lidocaine received. Acute moderate hypoxia increased brain blood flow, although it did not affect liver or renal perfusion. Chronic moderate hypoxia did not significantly change the blood flow to any of the organs studied. It was concluded that acute and chronic moderate hypoxia decreases the rate of elimination of both active metabolites of lidocaine without modifying the perfusion to the organs responsible for their elimination.

Differential migratory response of U-2 OS osteosarcoma cell to the various forms of platelet-derived growth factor

U-2 OS osteosarcoma cells are mesenchymal-derived transformed cells spontaneously expressing both platelet-derived growth factor (PDGF) A- and B-chain genes, and releasing PDGF AA dimers in culture. Using modified Boyden chemotactic chambers, platelet-purified PDGF was shown to be a chemoattractant for U-2 OS cells. More specifically, U-2 OS cells migrated in the presence of PDGF AB and BB dimers but not in the presence of PDGF AA dimers. This pattern of response was similar to that observed with human fibroblasts and this similarity is consistent with the fact that U-2 OS cells express PDGF receptor alpha- and beta-subunits in a similar fashion to human fibroblasts.

Presence of platelet-derived growth factor in normal and fibrotic lung is specifically associated with interstitial macrophages, while both interstitial macrophages and alveolar epithelial cells express the c-sis proto-oncogene

Normal lung structure is maintained by the presence of mesenchymal cells and their extracellular matrix products. The slow normal turnover of these cells is disrupted in fibrotic disorders, resulting in the in situ accumulation of mesenchymal cells and their extracellular matrix leading to a progressive alveolar wall thickening. Idiopathic pulmonary fibrosis (IPF) is a chronic fibrotic disorder of the lung characterized by a diffuse interstitial and intra-alveolar inflammation dominated by macrophages and polymorphonuclear neutrophils. Evaluation of alveolar macrophages (AM) obtained by bronchoalveolar lavage has previously shown that AM from normal individuals spontaneously release small amounts of platelet-derived growth factor (PDGF), a chemotactic and growth factor for mesenchymal cells, whereas AM from IPF patients spontaneously release increased amounts of biologically active PDGF, suggesting its involvement in mesenchymal cell accumulation. However, other cells such as endothelial cells and vascular smooth muscle cells can also release PDGF in vitro. In order to specify PDGF location in lung parenchyma, open lung biopsies from normal individuals and IPF patients were examined by immunohistochemistry using an anti-PDGF antibody and by in situ hybridization using PDGF A-chain and B-chain gene probes. In normal as well as in fibrotic lung, PDGF was only present in relation with interstitial macrophages but not with any other inflammatory cells or mesenchymal cells. Furthermore, the percentage of PDGF-positive macrophages in IPF was 3-fold increased in comparison to normal lung. In addition, the percentage of PDGF-positive macrophages was the same in fibrotic and nonfibrotic areas of IPF lungs.(ABSTRACT TRUNCATED AT 250 WORDS)

The inotropic effect of digoxin on an isolated rat heart in hypercapnia and (or) hypoxia

The explanation for the increased frequency of troubles with digoxin therapy in patients with chronic pulmonary diseases is debated. The reported effects of hypoxia in vivo on myocardial levels of digoxin are contradictory, and there have been few studies on the effects of hypercapnia. In the past, it has been shown in rat myocardial tissue at rest in vitro that hypoxia decreased and hypercapnic acidosis increased the digoxin uptake. We performed a new study in vitro in an isolated beating rat heart perfused at constant flow (37 degrees C) and stimulated at a constant frequency (6 Hz). The performances were recorded with an intraventricular balloon equipped with a tip-manometer catheter. The action of digoxin was studied by recording systolic pressure (PS) and diastolic pressure (PD), the left ventricular developed pressure (LVDP = PS - PD), the (dP/dt)max, and the ratio (dP/dt)max/PS. First, the heart was perfused for 30 min with a modified Tyrode's solution perfusate aerated with carbogen (pH = 7.40; PCO2 = 37 mmHg; PO2 = 530 mmHg) (1 mmHg = 133.32 Pa). Various parameters of contractions were recorded (initial control values). Then the heart was perfused for 15 min with Tyrode's solution aerated either with a hypoxic gas mixture (pH = 7.41; PCO2 = 36 mmHg; PO2 = 122 mmHg), a hypercapnic gas mixture (pH = 7.08; PCO2 75 mmHg; PO2 = 485 mmHg), or a hypoxic-hypercapnic gas mixture (pH = 7.09; PCO2 = 73 mmHg; PO2 = 124 mmHg). Control hearts were continuously perfused with Tyrode's solution aerated with carbogen.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac derived neutrophil chemotactic factors; preliminary biochemical characterization

The purpose of this study is to investigate whether isolated hearts perfused with cardioplegic solution release inflammatory mediators such as neutrophil chemotactic factors (NCF). Three conditions were tested, including: (1) perfusion of rabbit hearts with crystalloid cardioplegic solution (4 degree C) saturated with air (95% oxygen) and containing dextrose (i.e. complete system), (2) perfusion of rabbit hearts with non-oxygenated cardioplegic solution, containing dextrose (i.e. minus oxygen system), and (3) perfusion of hearts with cold cardioplegic solution saturated with air in the absence of dextrose (i.e. minus dextrose system). At various time intervals (5 min, 1, 2, 3 and 4 h) samples of circulated perfusate were removed and assayed for the presence of NCF using modified Boyden chambers. Rabbit peritoneal neutrophils were the indicator cells. The standard chemoattractant, f-Met-Leu-Phe (f-MLP) was the positive control. High levels of neutrophil chemotactic activity were detected in perfusate of all above described hearts perfused for 4 h (i.e. 194 +/- 22% of f-MLP control--complete system, 126 +/- 13%--minus oxygen and 136 +/- 10%-minus dextrose). Histological evaluation of these hearts showed evidence of global ischemia. We also detected significant levels of NCF in effluent of hearts perfused for 5 min, 1, 2 and 3 h. Similar to perfused hearts, isolated rabbit hearts incubated for 4 h with non-oxygenated cardioplegic solution (in presence and absence of dextrose) released high levels of NCF (132 +/- 18%-intact heart; and 100 +/- 6% myocardial segments). Standard checkerboard analysis revealed that the observed activity released from these hearts is chemotactic.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of hypoxia and hypercapnia on atrial natriuretic factor and plasma renin activity in conscious dogs

1. The aim of the present study was to assess the effects of hypercapnia or hypoxia on plasma concentrations of atrial natriuretic factor (ANF) in conscious unrestrained dogs. 2. For this purpose, chronically instrumented dogs were exposed in a random order to either room air, or to an atmosphere containing 21% O2/10% CO2/69% N2 to produce hypercapnia, or 10% O2/3% CO2/87% N2 to produce hypoxia without respiratory alkalosis. 3. Plasma concentrations of ANF did not change significantly during hypoxia. 4. In contrast, during hypercapnia, plasma concentrations of ANF increased by more than 100% and returned to baseline at the end of hypercapnia. 5. Hypercapnia, but not hypoxia, induced an increase in left atrial and central venous pressures. 6. We conclude that hypercapnia increases plasma ANF concentration, and that this increase may be secondary to an increase of the left and right atrial pressures. These phenomena may explain the increase in diuresis and natriuresis which has been described during hypercapnia.

Effect of the standardized Ginseng Extract G115 on the metabolism and electrical activity of the rabbit's brain

The objective of this original investigation was to study the effect of the standardized Ginseng Extract G115 on the metabolic activity and ECoG of the rabbit's brain. The results showed significant increase of the glucose uptake with simultaneous significant reduction of the lactate, pyruvate and lactate/pyruvate ratio. These findings indicate shift of glucose utilization by the drug from anaerobic to the more economical pathway. G115 was also shown to produce a desynchronizing effect on the electrocorticogram (ECoG) which correlated well with the biochemical findings.

A comparative study of antidepressants in the treatment of depressive states

The effect of six antidepressants has been investigated in six groups of twenty patients suffering from depressive states. The over-all response of the six groups, as well as the response of the individual target symptoms of depression according to the Hamilton Rating Scale are reported.

Psychometric assessment of the therapeutic efficiency of antidepressant agents

A clinical trial of four weeks duration was conducted involving a total of thirty depressed patients, of both sexes, aged between twenty and thirty-four years. The total number of patients was divided into three groups of ten patients each. One group received amitriptyline, the second group was administered noxiptyline and the third group was given dibenzepine. All drugs were administered orally. Patients were submitted to psychometric testing before and after drug administration. The tests used included the 'Hamilton Rating Scale for depression', the 'Hildreth Feeling Scale' and the 'D Scale' and the 'Trail Making Test' for the evaluation of psychomotor retardation. It was concluded that the Hamilton Rating Scale was the most relatively sensitive test utilized in assessing the depressive state and its improvement. Amitriptyline was found to be mostly anxiolytic; noxiptyline controlled both depression and anxiety to approximately the same extent; and dibenzepine was found to be a mood-elevating drug with an energizing action.