Three-dimensional radiographic assessment of the mandibular interforaminal donor site in different vertical facial growth types

PURPOSE

To assess volumetrically, the impact of vertical facial growth types (VFGT) on the mandibular interforaminal region as a potential bone donor site.

MATERIAL AND METHODS

60 cone beam computed tomography (CBCT) scans of adult individuals were classified in three groups according to their SN-GoGn angle: hypodivergent group (hG) (N=20), normodivergent group (NG) (N=19) and hyperdivergent group (HG) (N=21). Total harvestable bone volume (TBV), cortico-cancellous bone volume (CBV-cBV), and cortical bone surface (CBS) were evaluated. ANOVA test followed by Tukey post hoc tests were used to compare the mean continuous outcomes according to their VFGT.

RESULTS

The whole sample showed a mean TBV of 1376.32±541.01mm³, CBV of 468.52±121.54mm³ and cBV of 908.73±474.71mm³. The mean CBS amounted to 782.58±146.80mm². The comparison between the groups stated a significantly different mean TBV and cBV (-p-value<0.001). The mean CBS was significantly different (-p-value=0.015): the smallest for the NG, but not significantly different (-p-value<0.001): the highest for the HG, intermediate for the NG and the smallest for the hG.

CONCLUSION

Hypodivergent individuals have the thickest cancellous bone suitable for an onlay bone graft, while hyperdivergent individuals have the thinnest bone ideal for a 3D grafting approach.

Periodontal Inflammation Primes the Systemic Innate Immune Response

The presence of periodontal diseases (PDs) often strongly correlates with other severe chronic inflammatory conditions, including cardiovascular disease, diabetes, and arthritis. However, the mechanisms through which these diseases interact are unclear. In PD, tissue and bone destruction in the mouth is driven by elevated recruitment of polymorphonuclear neutrophils (PMNs), which are primed and recruited from the circulation to sites of inflammation. We predicted that systemic effects on PMN mobilization or priming could account for the interaction between PD and other inflammatory conditions. We tested this using a mouse model of ligature-induced PD and found elevated PMN counts specifically in bone marrow, supporting a systemic effect of periodontal tissue inflammation on PMN production. In contrast, mice with induced peritonitis had elevated PMN counts in the blood, peritoneum, and colon. These elevated counts were further significantly increased when acute peritonitis was induced after ligature-induced PD in mice, revealing a synergistic effect of multiple inflammatory events on PMN levels. Flow cytometric analysis of CD marker expression revealed enhanced priming of PMNs from mice with both PD and peritonitis compared to mice with peritonitis alone. Thus, systemic factors associated with PD produce hyperinflammatory PMN responses during a secondary infection. To analyze this systemic effect in humans, we induced gingival inflammation in volunteers and also found significantly increased activation of blood PMNs in response to ex vivo stimulation, which reverted to normal following resolution of gingivitis. Together, these results demonstrate that periodontal tissue inflammation has systemic effects that predispose toward an exacerbated innate immune response. This indicates that peripheral PMNs can respond synergistically to simultaneous and remote inflammatory triggers and therefore contribute to the interaction between PD and other inflammatory conditions. This suggests larger implications of PD beyond oral health and reveals potential new approaches for treating systemic inflammatory diseases that interact with PD.

Hemorrhagic transformation after stroke: inter- and intrarater agreement

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) is a complication of stroke that can occur spontaneously or after treatment. We aimed to assess the inter- and intrarater reliability of HT diagnosis.

METHODS

Studies assessing the reliability of the European Cooperative Acute Stroke Study (ECASS) classification of HT or of the presence (yes/no) of HT were systematically reviewed. A total of 18 raters independently examined 30 post-thrombectomy computed tomography scans selected from the Aspiration versus STEnt-Retriever (ASTER) trial. They were asked whether there was HT (yes/no), what the ECASS classification of the particular scan (0/HI1/HI2/PH1/PH2) (HI indicates hemorrhagic infarctions and PH indicates parenchymal hematomas) was and whether they would prescribe an antiplatelet agent if it was otherwise indicated. Agreement was measured with Fleiss' and Cohen's κ statistics.

RESULTS

The systematic review yielded four studies involving few (≤3) raters with heterogeneous results. In our 18-rater study, agreement for the presence of HT was moderate [κ = 0.55; 95% confidence interval (CI), 0.41-0.68]. Agreement for ECASS classification was only fair for all five categories, but agreement improved to substantial (κ = 0.72; 95% CI, 0.69-0.75) after dichotomizing the ECASS classification into 0/HI1/HI2/PH1 versus PH2. The inter-rater agreement for the decision to reintroduce antiplatelet therapy was moderate for all raters, but substantial among vascular neurologists (κ = 0.70; 95% CI, 0.57-0.84).

CONCLUSION

The ECASS classification may involve too many categories and the diagnosis of HT may not be easily replicable, except in the presence of a large parenchymal hematoma.

Canagliflozin-loaded magnetic nanoparticles as potential treatment of hypoxic tumors in combination with radiotherapy

AIM

To synthesize magnetic nanoparticles loaded with the SGLT2-inhibitor canagliflozin (CANA) and evaluate its anticancer potential under normoxic and hypoxic conditions in combination or not with radiotherapy.

MATERIAL & METHODS

Iron oxide nanoparticles were synthesized via an alkaline hydrolytic precipitation of iron precursor in the presence of poly(methacrylic acid)-graft-poly(ethyleneglycol methacrylate). CANA was conjugated to the nanoparticles using N-ethyl-N'-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide chemistry. The anticancer efficacy of the nanoparticles was evaluated in cancer cell lines and in a mouse PDV C57 tumor model.

RESULTS

In the mouse xenograft cancer model, the combination of CANA-loaded nanoparticles with radiotherapy (in the presence of an external magnetic field at the tumor site) exhibited higher antitumor activity compared with the combination of free CANA with radiotherapy.

CONCLUSION

The results obtained indicate the potential that the combination of selective delivery of a SGLT2 inhibitor such as CANA with radiotherapy holds as an anticancer treatment.

Roles of DNA repair enzyme OGG1 in innate immunity and its significance for lung cancer

Cytokines are pivotal mediators of the immune response, and their coordinated expression protects host tissue from excessive damage and oxidant stress. Nevertheless, the development of lung pathology, including asthma, chronic obstructive pulmonary disease, and ozone-induced lung injury, is associated with oxidant stress; as evidence, there is a significant increase in levels of the modified guanine base 7,8-dihydro-8-oxoguanine (8-oxoG) in the genome. 8-OxoG is primarily recognized by 8-oxoguanine glycosylase 1 (OGG1), which catalyzes the first step in the DNA base excision repair pathway. However, oxidant stress in the cell transiently halts enzymatic activity of substrate-bound OGG1. The stalled OGG1 facilitates DNA binding of transactivators, including NF-κB, to their cognate sites to enable expression of cytokines and chemokines, with ensuing recruitments of inflammatory cells. Hence, defective OGG1 will modulate the coordination between innate and adaptive immunity through excessive oxidant stress and cytokine dysregulation. Both oxidant stress and cytokine dysregulation constitute key elements of oncogenesis by KRAS, which is mechanistically coupled to OGG1. Thus, analysis of the mechanism by which OGG1 modulates gene expression helps discern between beneficial and detrimental effects of oxidant stress, exposes a missing functional link as a marker, and yields a novel target for lung cancer.

Hyperphosphatemic familial tumoral calcinosis secondary to fibroblast growth factor 23 (FGF23) mutation: a report of two affected families and review of the literature

Hyperphosphatemic familial tumoral calcinosis (HFTC), secondary to fibroblast growth factor 23 (FGF23) gene mutation, is a rare genetic disorder characterized by recurrent calcified masses. We describe young Lebanese cousins presenting with HFTC, based on a retrospective chart review and a prospective case study. In addition, we present a comprehensive review on the topic, based on a literature search conducted in PubMed and Google Scholar, in 2014 and updated in December 2017. While the patients had the same previously reported FGF23 gene mutation (homozygous c.G367T variant in exon 3 leading to a missense mutation), they presented with variable severity and age of disease onset (at 4 years in patient 1 and at 23 years in patient 2). A review of the literature revealed several potential patho-physiologic pathways of HFTC clinical manifestations, some of which may be independent of hyperphosphatemia. Most available treatment options aim at reducing serum phosphate level, by stimulating renal excretion or by inhibiting intestinal absorption. HFTC is a challenging disease. While the available medical treatment has a limited and inconsistent effect on disease symptomatology, surgical resection of calcified masses remains the last resort. Research is needed to determine the safety and efficacy of FGF23 replacement or molecular therapy, targeting the specific genetic aberration. Hyperphosphatemic familial tumoral calcinosis is a rare genetic disorder characterized by recurrent calcified masses, in addition to other visceral, skeletal, and vascular manifestations. It remains a very challenging disease.

A Triphenylphosphonium-Functionalized Mitochondriotropic Nanocarrier for Efficient Co-Delivery of Doxorubicin and Chloroquine and Enhanced Antineoplastic Activity

Drug delivery systems that target subcellular organelles and, in particular, mitochondria are considered to have great potential in treating disorders that are associated with mitochondrial dysfunction, including cancer or neurodegenerative diseases. To this end, a novel hyperbranched mitochondriotropic nanocarrier was developed for the efficient co-delivery of two different (both in chemical and pharmacological terms) bioactive compounds. The carrier is based on hyperbranched poly(ethyleneimine) functionalized with triphenylphosphonium groups that forms ~100 nm diameter nanoparticles in aqueous media and can encapsulate doxorubicin (DOX), a well-known anti-cancer drug, and chloroquine (CQ), a known chemosensitizer with arising potential in anticancer medication. The anticancer activity of this system against two aggressive DOX-resistant human prostate adenocarcinoma cell lines and in in vivo animal studies was assessed. The co-administration of encapsulated DOX and CQ leads to improved cell proliferation inhibition at extremely low DOX concentrations (0.25 μΜ). In vivo experiments against DU145 human prostate cancer cells grafted on immunodeficient mice resulted in tumor growth arrest during the three-week administration period and no pervasive side effects. The findings put forward the potential of such targeted low dose combination treatments as a therapeutic scheme with minimal adverse effects.

The molecular basis of fertilization (Review)

Fertilization is the fusion of the male and female gamete. The process involves the fusion of an oocyte with a sperm, creating a single diploid cell, the zygote, from which a new individual organism will develop. The elucidation of the molecular mechanisms of fertilization has fascinated researchers for many years. In this review, we focus on this intriguing process at the molecular level. Several molecules have been identified to play a key role in each step of this intriguing process (the sperm attraction from the oocyte, the sperm maturation, the sperm and oocyte fusion and the two gamete pronuclei fusion leading to the zygote). Understanding the molecular mechanisms of the cell-cell interactions will provide a better understanding of the causes of fertility issues due to fertilization defects.

N-bromotaurine surrogates for loss of antiproliferative response and enhances cisplatin efficacy in cancer cells with impaired glucocorticoid receptor

Glucocorticoids (GCs) are frequently used in anticancer combination regimens; however, their continuous use adds selective pressure on cancer cells to develop GC-resistance via impairment of the glucocorticoid receptor (GR), therefore creating a need for GC-alternatives. Based on the drug repurposing approach and the commonalities between inflammation and neoplasia, drugs that are either in late-stage clinical trials and/or already marketed for GC-refractory inflammatory diseases could be evaluated as GC-substitutes in the context of cancer. Advantageously, unlike new molecular entities currently being de novo developed to restore GC-responsiveness of cancer cells, such drugs have documented safety and efficacy profile, which overall simplifies their introduction in clinical cancer trials. In this study, we estimated the potential of a well-established, multistage, cell line-based, mouse skin carcinogenesis model to be exploited as an initial screening tool for unveiling covert GC-substitutes. First, we categorized the cell lines of this model to GC-sensitive and GC-resistant, in correlation with their corresponding GR status, localization, and functionality. We found that GC-resistance starts in papilloma stages, due to a dysfunctional GR, which is overexpressed, DNA binding-competent, but transactivation-incompetent in papilloma, squamous, and spindle stages of the model. Then, aided by this tool, we evaluated the ability of N-bromotaurine, a naturally occurring, small-molecule, nonsteroid anti-inflammatory drug which is under consideration for use interchangeably/in replacement to GCs in skin inflammations, to restore antiproliferative response of GC-resistant cancer cells. Unlike GCs, N-bromotaurine inhibited cell-cycle progression in GC-resistant cancer cells and efficiently synergized with cisplatin, thus indicating a potential to be exploited instead of GCs against cancer.

Coeliac disease presenting as severe hypoglycaemia in youth with type 1 diabetes

BACKGROUND

Coeliac disease is an autoimmune disorder classically characterized by gastrointestinal symptoms and poor growth. The disease can be difficult to recognize in patients with Type 1 diabetes mellitus. Some clinicians find treatment of the disease in asymptomatic individuals controversial.

CASE REPORTS

Two adolescent female patients with Type 1 diabetes experienced recurrent hypoglycaemic seizures. Neither patient reported gastrointestinal symptoms or poor growth. After diagnosis and treatment of coeliac disease, hypoglycaemia resolved.

CONCLUSION

These cases illustrate how frequent unexplained severe hypoglycaemia can be an atypical presentation of coeliac disease in youth with Type 1 diabetes. Furthermore, they emphasize the importance of screening and treatment of coeliac disease in asymptomatic patients with Type 1 diabetes. Although controversial, management of coeliac disease in these asymptomatic patients can prevent the vicious cycle of recurrent hypoglycaemia and decrease risk for morbidity and death.

[A case of alcohol-induced ketoacidosis?]

We report a case of severe ketoacidosis. Initially the patient showed metabolic acidosis, the anion gap was positive and there was neither hyperlactatemia nor intoxication with acid substances. As the rate of glycemia was high (17.8 mmol/L), the diagnosis of diabetic ketoacidosis was proposed. Under treatment with continuous IV injection of insulin, hypoglycemia (1.8 mmol/L) appeared rapidly, while urine bioreactive test was positive for ketonuria, but negative for glycosuria. We finally concluded that it was an alcoholic ketoacidosis. The history of the patient confirmed the diagnosis : chronic alcoholism with recent increased of alcohol intake which provoked vomiting and fasting. This case report shows the difficulty in distinguishing between alcoholic ketoacidosis and diabetic ketoacidosis. We discuss the diagnostic strategy and particularly biologic data in the light of pathophysiologic mechanism of alcoholic ketoacidosis.

Frequency of the CCR5-delta 32 chemokine receptor gene mutation in the Lebanese population

A direct correlation between HIV infection and mutation in the chemokine receptor [CCR5] gene has been established. However, such correlation has never been investigated in Lebanon. We report the frequency of the CCR5-delta 32 mutation in a r and om sample of 209 healthy, HIV-1 seronegative Lebanese aged 19-68. Overall, 4.8% were heterozygous for the mutation. Homozygosity was absent from our sample. The frequency for the CCR5-delta 32 allele was 2.5%. Distribution of the mutation was unaffected by sex, age, religion or educational level. The frequency in the Lebanese population is consistent with that in the origin of the mutation in northern Europe. This could be attributed to a gene flow into the Middle East from northern Europe

Frequency of the CCR5-delta 32 chemokine receptor gene mutation in the Lebanese population

A direct correlation between HIV infection and mutation in the chemokine receptor (CCR5) gene has been established. However, such correlation has never been investigated in Lebanon. We report the frequency of the CCR5-delta 32 mutation in a random sample of 209 healthy, HIV-1 seronegative Lebanese aged 19-68. Overall, 4.8% were heterozygous for the mutation. Homozygosity was absent from our sample. The frequency for the CCR5-delta 32 allele was 2.5%. Distribution of the mutation was unaffected by sex, age, religion or educational level. The frequency in the Lebanese population is consistent with that in the origin of the mutation in northern Europe. This could be attributed to a gene flow into the Middle East from northern Europe.

Hypercalcemia in Langerhans' cell granulomatosis with elevated 1,25 dihydroxyvitamin D (calcitriol) level

A 48-year-old woman presented with a history of premature menopause, polyuria, polydipsia, fever, and diffuse bony tenderness. Her evaluation revealed central diabetes insipidus, hypothalamic amenorrhea, an elevated free calcium on multiple occasions with an elevated 1,25 dihydroxyvitamin D level, and osteoporosis by densitometry. Skeletal series revealed multiple lytic lesions involving the long bones. The diagnosis of Langerhans' cell granulomatosis was made. She was treated with hormone replacement therapy, radiotherapy, and vinblastine, with a dramatic improvement in her pain and a near normalization of her free calcium. Whereas hypercalcemia has been described in several granulomatous disorders and is secondary to unregulated extrarenal production of 1,25 dihydroxyvitamin D, it is, however, extremely rare in Langerhans' cell granulomatosis. This is the first case report of Langerhans' cell granulomatosis with hypercalcemia and documented elevated increased 1,25 dihydroxyvitamin D level that responded to the treatment of her primary disease.

[Diffuse colitis associated with mycophenolate mofetil treatment: apropos of 1 case]

Mycophénolate mofétil (MMF) or Cellcept is a potent immunosuppressor that inhibits purin synthesis used to prevent human allograft rejection. The most important secondary effects include haematological and intestinal disorders. Among them, diarrhea is the most common. It is dose-dependant and appears commonly during the first 2 months of treatment. Its physiopathology remains unclear. We reported a case of colitis, 6 months after a kidney transplantation. The patient was treated since day 2 with 2 grams per day of MMF. Morphological analysis showed a diffuse colitis from the coecum to the rectum. Histological samples confirmed a colitis with atrophic crypts but with mucosal secretions and some cryptic abscesses. No granuloma or CMV inclusion was founded. Histochemical immunostaining for CMV was negative. Finally, symptoms regressed within 5 days after tapering down MMF dose in association with metronidazole treatment. The role of MMF in inducing colitis is discussed.

Intraabdominal panniculitis. Report of three cases and review of the literature

Intraabdominal panniculitis is a rare, benign idiopathic disorder of the mesentery. Patients usually present with abdominal pain and a palpable mass. The cross-sectional imaging findings are characteristic and consist of a fibrofatty central mesenteric mass lesion encapsulating the mesenteric vessels with displacement of the bowel loops, that can suggest the diagnosis. Imaging is also important to establish a definitive diagnosis by an image-guided percutaneous biopsy, assess extent of the disease for selection of appropriate therapy, exclude associated abnormalities namely malignancies, and for follow-up.

A randomized prospective controlled trial of laparoscopic extraperitoneal hernia repair and mesh-plug hernioplasty: a study of 315 cases

Inguinal hernias can be repaired by traditional methods, tension-free, mesh-plug hernioplasty, and the less conventional laparoscopic techniques that have the added advantage of quicker recovery. Between September 1994 and September 1997, a prospective randomized controlled trial was performed on 292 patients with a total of 315 hernias. Of these, 150 patients with 169 hernias underwent the extraperitoneal laparoscopic repair (TEP) and 142 patients with 146 hernias were treated with mesh-plug hernioplasty. Patients were examined at 1 week after surgery and every 4 months thereafter for 3 years. Operative results, postoperative recovery, complications, and recurrences were recorded. Follow-up was complete for 89% of the patients. The average operative time was 31.5 minutes for the TEP and 30.5 minutes for the mesh-plug hernioplasty. The average operative time for the last 75 laparoscopic cases was 20 minutes, 10 minutes shorter than the open-surgery group. The overall recurrence rate was (2.5%) for the TEP and (3%) for the mesh-plug hernioplasty. Patients undergoing the laparoscopic repair consumed less narcotic analgesic and returned to their normal activity 1 week sooner than the open-surgery group. A median of 8 days vs. 15 days was required for patients to return to work, respectively, in the TEP and open-surgery group (p<0.01). Intraoperative complications occurred in two patients (1.3%) in the TEP repair. Both had peritoneal tear that mandated conversion to the TAPP repair. There were no major postoperative complications. A total of 20 (13%) minor postoperative complications occurred in the TEP. Thirty-three (23%) minor complications occurred in the open-surgery group (p<0.01). Ninety-eight percent of the patients were discharged the same day in the open-surgery group compared to 100% in the laparoscopy group. Patients with inguinal hernias who undergo extraperitoneal laparoscopic repair have the same recurrences and hospital stay but recover more rapidly, consume less analgesic, and have fewer minor complications than those who undergo the mesh-plug hernioplasty.

A comparative study of laparoscopic extraperitoneal and transabdominal preperitoneal herniorrhaphy

Laparoscopic minimally invasive surgical procedures are gaining popularity. Laparoscopic hernia repair is now less controversial and more readily acceptable, with at present numerous technical modifications described in an attempt to define the best procedure. Between November 1992 and February 1995, a nonrandomized trial of laparoscopic inguinal herniorrhaphy was performed on 115 patients with a total of 120 hernias. Of these 58 patients with 60 hernias underwent the transabdominal preperitoneal patch repair (TAPP) without plug and 57 patients with a total of 60 hernias were offered the extraperitoneal (EXTRA) approach using a distension balloon. The average operative time was 55 min for the TAPP and 50 min for the EXTRA procedure. The overall recurrence rate was 1.7% with a follow up of 1-27 months. The recurrence rate was 3.4% for the TAPP and none for the EXTRA approach. All patients returned to their normal activity within 1 week of discharge. Patients undergoing the EXTRA repair consumed less amount of narcotic analgesic than did the group undergoing the TAPP repair. Of the EXTRA group 58% did not require any analgesic, compared to 22% of the TAPP group (p < 05). There were no intraoperative complications. A total of 8 (6.9%) postoperative complications occurred in 115 patients. Four complications (6.9%) occurred in the TAPP procedure: 2 transient urinary retentions, 1 pulmonary edema, and 1 Richter's type hernia. Four (6.9%) complications occurred in the EXTRA procedure: 1 urinary retention, 2 abdominal wall ecchymoses, and 1 thoracic pain. Hospital stay was shorter for the EXTRA group: 57% were discharged the same day and 98% were discharged within 24 h of their operations for the EXTRA group compared to 10 and 84%, respectively, for the TAPP (p < 0.05). Laparoscopic extraperitoneal hernia repair can be accomplished with shorter hospitalization and less analgesic requirement than the TAPP repair. The overall incidence of complications, the recurrence rate, and the return to normal activity were not different between the two types of repair.

Laparoscopic appendectomy versus open appendectomy: retrospective assessment of 200 patients

OBJECTIVE

To compare laparoscopic appendectomy (LA) with traditional methods as the primary treatment for acute appendicitis.

DESIGN

A retrospective case series.

SETTING

A regional, nonuniversity hospital in northwestern Quebec.

PATIENTS

Two hundred patients with a clinical diagnosis of acute appendicitis: 100 (43 men, 57 women; mean age 27 years) underwent laparoscopic appendectomy and 100 (67 men, 33 women; mean age 21 years) had an open appendectomy (OA).

INTERVENTIONS

LA or OA.

MAIN OUTCOME MEASURES

Operating time, rate of conversion to OA, need for analgesia, morbidity and outcome.

RESULTS

LA was successful in 88% of patients. The mean operating time was 50 minutes for LA versus 24 minutes for OA. On average, patients of the LA group had a 1-day decrease in postoperative hospital stay (2.6 versus 3.6 days). The wound infection rate was lower in the LA group (2% versus 12%) as was the intra-abdominal abscess rate (2% versus 6.0%). There were no deaths in either group. The overall morbidity was 4.5% for the LA group and 18% for the OA group. A clear tendency toward a shorter convalescence was seen in the LA group.

CONCLUSIONS

LA is a safe and viable treatment alternative for acute appendicitis. Prospective randomized studies are needed to confirm its potential advantages.

[Survival capacity of genetically altered Escherichia coli strains. 2. Survival of pure cultures in different water and soil matrices]

The survival of two genetically engineered E. coli strains (L+, CAG+) compared to that of 4 control strains (N0, K12, L-, CAG-), was investigated in drinking water, surface water, sewage and soil under different conditions. Both genetically manipulated strains are able to produce Prourokinase, an anticoagulant. It was found, that all strains died off inspite of high inoculated bacterial densities. In drinking water, no bacteria could be recultivated immediately following inoculation. Upon inoculation in surface water, the genetically manipulated strains L+ and CAG+ were more sensitive than the other strains. The same was found for sewage under aerobic conditions, whereby, the control strains N0 and K12 as well as the wild-strains of the genetically manipulated organisms, L- and CAG- survived the whole experimental period and kept their numbers at a level between 100 and 1000 CFU/ml. Under anaerobic conditions, a die-off of all tested strains was similarly registered with time. The influence of the autochthonous microflora of sewage water could be documented in that, under these conditions, all test strains survived the whole experimental period of 31 days with the exception of the genetically manipulated strain CAG+. In soil experiments, it was found that the humus-rich garden soil was more effective in eliminating the E. coli strains than sand. The antagonistic effect of the autochthonous soil microflora was only clearly seen in experiments with garden soil. However, these results did not meet the expectations for the two CAG strains, for which a longer survival period had been previously established for in nutrient rich soil. In contrast to the E. coli control strains N0 and K12, the two L strains and the CAG+ strain survived the whole test period of 36 days. It can be concluded that under these simulated environmental conditions, all tested strains of E. coli die off more or less in a short period of time following inoculation with the autochthonous microflora of environmental samples.

[Survival ability of genetically engineered strains of Escherichia coli. 1. Physiological characterization and the effect of different physiochemical conditions]

Two genetically engineered E. coli strains L+ and CAG+ possessing the ability to produce the enzyme Pro-urokinase and showing additionally ampicillin resistance, and wild-strains L- and CAG-, were characterized using 328 physiological tests. Their test profiles were compared with those of 30 clinical and nonclinical E. coli isolates. This biotyping made a differentiation and recognition of the genetically manipulated strains possible. It also allowed distinguishing them from the other tested isolates. The genetically engineered strains showed a narrower activity spectrum compared with their wild-strains. However, based on differentiating characteristics, all strains could be clearly biochemically identified as E. coli. Under different laboratory test conditions (organic load, pH, salt content, temperature), the E. coli strains showed no striking features or peculiarities with respect to their survival compared to data from literature. However, low pH (pH less than 5), high salt content (greater than 7%) as well as low (less than 8 degrees C) and high (greater than 37 degrees C) incubation temperatures clearly reduced their ability to survive. Apart from a few exceptions (e.g. survival of strain L+ at 44 degrees C and pH 7 with high cell densities), the survival of the genetically engineered strains corresponded to that of the control and wild-strains. Both CAG strains, especially the genetically manipulated strain CAG+, showed in many cases reduced viability compared with the other strains.

A comparative immunohistochemical study of peritoneal and ovarian serous tumors, and mesotheliomas

The distinction between serous neoplasms of the peritoneum in women and conventional mesothelioma can be difficult. In order to determine any significant immunohistochemical differences, formalin-fixed, paraffin-embedded sections of 10 peritoneal serous tumors (PST), 10 ovarian serous tumors (OST), and 10 epithelial mesotheliomas were evaluated with a panel of 10 antibodies directed against carcinoembryonic antigen (CEA: polyclonal, monoclonal), high molecular weight keratin (34 beta E12), low molecular weight keratin (35 beta H11), Leu-M1, TAG-72 (monoclonal antibody B72.3), human milk fat globulin (HMFG-2), vimentin, placental alkaline phosphatase (PLAP), and S-100 protein. The antibodies CEA, Leu-M1, and B72.3 had the most discriminatory value in differentiating serous tumors from mesothelioma. Eighty-five percent of PSTs and OSTs (17 of 20) were positive with CEA, Leu-M1, and/or B72.3. None of the mesotheliomas stained for CEA or Leu-M1; three mesotheliomas had very focal positivity with B72.3 (1% or less). Vimentin, PLAP, HMGF-2, keratin, and S-100 had no significant discriminatory value. Epithelial mucin was present in 80% of serous tumors, while the mesotheliomas lacked epithelial mucin. Leu-M1, CEA, and/or B72.3 positivity in a peritoneal tumor supports a diagnosis of serous tumor. However, since some PST do not stain for any of the three antibodies and the focal nature of positive reactions in some cases may be difficult to interpret, exclusion of mesotheliomas is enhanced by the use of mucin stains.

Dissolution rate studies from a stationary disk/rotating fluid system

The dissolution rates for hydrocortisone alcohol and acetate were determined using a stationary disk/rotating fluid system. The hydrocortisone was compressed in a tablet die, and the die placed in a vessel above a rotating magnetic bar. Dissolution rates were evaluated in aqueous media under conditions involving the following independent variables: solubility (Cs), diffusion coefficient (D), viscosity (v), rotational speed (omega), and tablet radius (r). A design equation which relates dissolution rate (R) to these variables was formulated for the system R alpha Cs D2/3 (v) -1/6(omega)1/2(r)3/2 This design equation adequately represents the system, which is related to fluid mechanics and convective diffusion models. The fluid mechanics model assumes that the fluid ideally rotates as solid-body rotation and the momentum layer is initiated at the outside radius of the tablet die. The convective diffusion model is based on the formation of a diffusion layer at the outside radius of the dissolving surface and a predictable relationship between the momentum and the mass transport quantities of bulk viscosity and diffusion coefficient. This configuration, like the rotating disk in a stationary fluid, offers the attractive attribute of being useful to study drug release mechanisms for systems of pharmaceutical interest.

Evaluation of a tube method for determining diffusion coefficients for sparingly soluble drugs

Evaluation of a non-steady state method using glass tubes for the determination of diffusion coefficients is the purpose of this study. Unlike capillaries, glass tubes accommodate a larger volume of solution, facilitating assay procedures. Tubes are more susceptible to convection than are capillaries, but this effect is anticipated and accounted for in experimental design and data treatment. Glass tubes, 66 or 90 mm in length and 2 mm outer diameter, were siliconized and then filled with aqueous drug solution and placed in a jacketed flask containing gently stirred solvent at 25 degrees C. Diffusion experiments were run from 140 to 168 hours. At the end of this time period, the tubes were removed from the flask, placed in an ultrasonic vibrator for one minute, and their contents assayed spectrophotometrically. Data collected using potassium chloride as the diffusant showed little tube-to-tube variability, demonstrating the precision of the tube method, while diffusion coefficients determined for benzoic acid and p-aminobenzoic acid using the tube method tested the accuracy of the method by comparing reasonably well with values obtained using standard methods such as the rotating disk, free boundary, and membrane cell. Experiments done with either hydrocortisone or sulfisoxazole as the diffusant demonstrated the appropriateness of the tube method for the study of the diffusion of sparingly soluble pharmaceutical solutes.

[Caudal anesthesia in children: two-year retrospective study]

Caudal anesthesia has been used on a daily basis for two years in the Department of Anesthesia of Saint-Vincent-de-Paul Hospital. A retrospective study on 231 children was done to specify the procedures, the indication and the dosage of local anesthetics.

Renal extraction of glutamine from plasma and whole blood: studies in dogs and rats

The change in plasma and blood cell pools of L-glutamine during a single pass through the kidney was studied in dogs and rats. It was shown that the glutamine content of blood cells does not change following one passage through the renal vascular bed in normal or acidotic dogs. Furthermore, an infusion of L-glutamine elevating by 10-fold the plasma concentration of this amino acid only minimally changed the blood cells' glutamine content. Therefore within the time frame of acute experiments, the dog blood cells can be assumed to be impermeable to glutamine in vivo. Accordingly, renal glutamine extraction can be measured using either whole blood or plasma arteriovenous difference in this species. However, the latter value is larger and therefore can be measured more accurately. In normal rats, no net renal glutamine extraction is measured. In contrast, a considerable renal glutamine uptake occurs in acidotic rats, 23% of the extracted glutamine coming from the blood cell pool. A load of glutamine in vivo significantly elevates both the plasma and the blood cell concentration. It is concluded (i) that the renal extraction of glutamine is best estimated using plasma arteriovenous difference in the dog, especially when the renal extraction is small; (ii) that whole blood measurements should be obtained in the rat.

Renal recovery from metabolic acidosis in the rat: no role for glutamine synthetase

The role of renal glutamine synthesis for the rapid decrease in renal ammoniagenesis occurring early in the recovery phase (24 h) of metabolic acidosis was studied in rats. L-Methionine-DL-sulfoximine (MSO), an irreversible inhibitor of glutamine synthetase, depressed the renal enzyme activity by 50% but did not impair the recovery from acidosis. Since extrarenal glutamine synthesis was decreased by this manoeuvre with lowering of blood glutamine, an intravenous load of L-glutamine sufficient to elevate blood concentration to 1 mM was superimposed on the MSO treatment. The glutamine load did not increase the ammoniuria. Infusion of glutamine alone to rats recovering from metabolic acidosis for 12-24 h did not change their ammoniuria. In contrast, glutamine administration together with HCl produced a marked ammoniuric response in rats recovering from acidosis. Conversely, the administration of bicarbonate to chronically acidotic rats acutely depressed renal ammonia production. It is concluded that glutamine synthetase activity is probably not required for recovery from metabolic acidosis, and that the post-acidosis alkaline rebound occurring in the rat may play a direct role in suppressing the ammoniagenic pathway either by drastic reduction in mitochondrial permeability for glutamine or acute inhibition of intramitochondrial deamidation of this amino acid.