Efficacy of Cemiplimab as Adjuvant or Neoadjuvant Therapy in the Treatment of Cutaneous Squamous Cell Carcinoma

INTRODUCTION

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer in the White population. Unfortunately, the prognosis of advanced cSCC is poor, and management can be challenging. Until recently, the choice of systemic medications was limited, and those that were available had modest efficacy. Cemiplimab is an anti-programmed cell-death protein 1 inhibitor and the first immunotherapeutic agent approved for the treatment of metastatic or locally advanced cSCC. The purpose of this study was to evaluate the efficacy of cemiplimab when used as adjuvant or neoadjuvant therapy in patients treated at our institution.

METHODS

A retrospective review of patients with locally advanced or metastatic cSCC who were treated with cemiplimab as adjuvant or neoadjuvant therapy at a single institution between February 2019 and November 2022 was performed. Response to treatment was objectively assessed based on Response Evaluation Criteria in Solid Tumors, version 1.1, criteria. The primary end point was objective response rate. Secondary endpoints included time to observed response, disease-control rate, progression-free survival, overall survival, and adverse effects of therapy.

RESULTS

A total of 6 patients were identified with a median age of 79 years (range, 51-90 years). Four patients had locally advanced cSCC, and 2 had distant metastasis. Cemiplimab was used as adjuvant therapy in 3 patients and neoadjuvant therapy in 2 patients. There was 1 patient in which it was used for limb salvage, who would have otherwise required an amputation. Objective response rate, complete response, and partial response were 66% (4 of 6), 33% (2 of 6), and 33% (2 pf 6), respectively. Average time to observed response was 2.9 months. Disease-control rate was 83% (5 of 6), and average progression-free survival was 10 months. Toxicity was reported in 2 patients, both of which were grade 1 severity.

CONCLUSIONS

Cemiplimab has established its utility in the treatment of advanced cSCC, demonstrating clinical efficacy while generally having a tolerable adverse effect profile. Our preliminary results suggest that cemiplimab has potential as an adjuvant or neoadjuvant therapy in combination with surgery for treatment of cSCC.

Earplug Umbilicoplasty: A Simple Method to Prevent Umbilical Stenosis in a Tummy Tuck

Objective: An aesthetically pleasing umbilicus is a vital component of patient satisfaction following an abdominoplasty. An umbilicus that is moderate to small is desired to achieve the best aesthetic result, but a small umbilicus has potential for stenosis. This article presents a method for umbilical stenting that creates a modest umbilicus, while preventing stenosis. Methods: All patients underwent abdominoplasty with an umbilical reconstruction using an inverted U-flap method between 2015 and 2017. An earplug was placed into the umbilicus at 2 weeks postoperatively for a total of 4 to 6 week. Patients were evaluated subjectively on the aesthetic outcome. Results: Twenty-one female patients were evaluated 6 weeks postsurgery. In all cases, both the patient and the surgeon were 100% satisfied with the final size. Umbilical size ranged from 1.8 to 2.2 cm. Conclusions: Use of an earplug for umbilical stenting is a simple and reproducible method to create an aesthetically pleasing umbilicus and avoid stenosis.

A new multi-channel Mach probe measuring the radial ion flow velocity profile in the boundary plasma of the W7-X stellarator

Ion flow velocity measurement in the edge and scraper-off layer region is beneficial to understand the confinement related phenomenon in fusion devices such as impurity transport and plays an important role in impurity control. During the Wendelstein 7-X (W7-X) operation phase 1.2a, a multi-channel (MC) Mach probe mounted on the multi-purpose manipulator has been used to measure radial profiles of edge ion flow velocity. This MC-Mach probe consists of two polar and two radial arrays of directional Langmuir pins (28 pins in total) serving for different aims, of which the polar arrays could obtain a polar distribution of ion saturation current, while the radial arrays can be used to study the dynamic process of a radially propagated event. In this paper, we report the observation of the radially outward propagation of a low frequency mode with a speed of around 200 m/s. The first measurement of the radial ion flow velocity profile using the MC-Mach probe in the boundary plasma of the W7-X with an island divertor will also be presented.

Oncoplastic Reduction Pattern Technique Following Removal of Giant Fibroadenoma

Objective: Oncoplastic surgery was developed to allow for large tumor excision and immediate breast reconstruction with the goal of optimal breast shape and symmetry. Although initially used in women who underwent lumpectomy for breast malignancy, these techniques can be useful for cosmetic issues caused by benign breast disease. We describe a modification of an inferior pedicle with Wise-pattern reduction mammoplasty for oncoplastic reconstruction of a giant fibroadenoma. Methods: A 30-year-old woman with size 32 DD breasts was referred by the surgical oncologist with a biopsy-proven fibroadenoma of the right breast. Surgical oncology excised the mass, and immediate reconstruction was performed with an inferolateral pedicle Wise-pattern reduction technique. Results: Immediately postoperatively, the patient showed excellent symmetry. Follow-up postoperatively showed good wound healing, preserved symmetry, and a viable, sensate nipple. Conclusions: Oncoplastic breast reconstruction in a reduction pattern technique after giant fibroadenoma removal provides an excellent outcome, allowing for improved symmetry.

Recipient Vessel Selection in Head and Neck Reconstruction

Objective: Recipient vessel caliber may be the single most important variable for flow to free tissue transfer. We performed cadaveric dissection of the external carotid artery and its branches to analyze average diameter in order to determine an algorithm for recipient vessel selection in head and neck reconstruction. Methods: The external carotid artery and branches were exposed on 3 lightly embalmed male human cadavers, aged 82 to 85 years. Each vessel was dissected, and luminal diameters were recorded with calipers. Results: The proximal ECA had the greatest average diameter (4 ± 0.6 mm) and potential flow; followed by distal ECA (2.85 ± 0.4 mm) facial (2.0 ± 0.6 mm), lingual (1.65 ± 0.6 mm), superior thyroid (1 ± 0.3  mm), and superficial temporal (0.85 ± 0.4 mm). There was a trend towards size variation between sides of the same cadaver. Conclusion: The external carotid artery has the greatest internal diameter and potential blood flow. It should be considered, when feasible, especially for defects of the upper third of the head. For defects of the lower third, the facial artery and the lingual artery should be utilized before the smaller diameter superior thyroid artery. Vessel selection is more challenging in the setting of radiation therapy, complex trauma, and prior neck surgery. In these settings, it is useful to have knowledge of the vascular anatomy and an objective algorithm for recipient vessel selection.

Foxm1 expression in prostate epithelial cells is essential for prostate carcinogenesis

The treatment of advanced prostate cancer (PCa) remains a challenge. Identification of new molecular mechanisms that regulate PCa initiation and progression would provide targets for the development of new cancer treatments. The Foxm1 transcription factor is highly up-regulated in tumor cells, inflammatory cells, and cells of tumor microenvironment. However, its functions in different cell populations of PCa lesions are unknown. To determine the role of Foxm1 in tumor cells during PCa development, we generated two novel transgenic mouse models, one exhibiting Foxm1 gain-of-function and one exhibiting Foxm1 loss-of-function under control of the prostate epithelial-specific Probasin promoter. In the transgenic adenocarcinoma mouse prostate (TRAMP) model of PCa that uses SV40 large T antigen to induce PCa, loss of Foxm1 decreased tumor growth and metastasis. Decreased prostate tumorigenesis was associated with a decrease in tumor cell proliferation and the down-regulation of genes critical for cell proliferation and tumor metastasis, including Cdc25b, Cyclin B1, Plk-1, Lox, and Versican. In addition, tumor-associated angiogenesis was decreased, coinciding with reduced Vegf-A expression. The mRNA and protein levels of 11β-Hsd2, an enzyme playing an important role in tumor cell proliferation, were down-regulated in Foxm1-deficient PCa tumors in vivo and in Foxm1-depleted TRAMP C2 cells in vitro. Foxm1 bound to, and increased transcriptional activity of, the mouse 11β-Hsd2 promoter through the -892/-879 region, indicating that 11β-Hsd2 was a direct transcriptional target of Foxm1. Without TRAMP, overexpression of Foxm1 either alone or in combination with inhibition of a p19(ARF) tumor suppressor caused a robust epithelial hyperplasia, but was insufficient to induce progression from hyperplasia to PCa. Foxm1 expression in prostate epithelial cells is critical for prostate carcinogenesis, suggesting that inhibition of Foxm1 is a promising therapeutic approach for prostate cancer chemotherapy.

RENAL EFFECTS OF HEMOGLOBIN INFUSIONS IN DOGS IN HEMORRHAGIC SHOCK

The immediate effects of treating hemorrhagic shock in dogs by replacing lost blood with 7 per cent hemoglobin solution were favorable, both on renal function and on general condition. However, subsequent transitory depression of the urea clearance for several days, shown by some of the treated animals, but not by untreated bled controls, indicates sufficient possibility of renal damage by the hemoglobin solution to prevent its recommendation at present as a blood substitute.

FAT METABOLISM IN NEPHRITIS

Determinations of the plasma lipoids and of the respiratory quotient and total metabolism (Tissot method) have been performed with nephritics and normal subjects before and after they ingested fat in the proportion of 1 gm. per kilo body weight. After fat ingestion a greater increase of fatty acids and lecithin was noted in the plasma of nephritics with initially high blood lipoids than in the plasma of normal subjects or of nephritics without constant lipemia. In cholesterol no differences were found. The nephritic patients with constant lipemia were able to burn fat as efficiently as normal individuals. The accumulation of fat in their blood may be due to a disturbance in the mechanism for transferring lipoids from the blood to the tissue depots.

PREPARATION OF DRIED HEMOGLOBIN WITHOUT LOSS OF ACTIVITY

The technique for freezing, drying, and preserving in vacuo which is in common use for plasma can be successfully applied to hemoglobin solutions when the hemoglobin is first deoxygenated to the extent of 99.7 per cent or more. In confirmation of Morrison and Hisey, the preliminary deoxygenation of the solution is found necessary to avoid formation of methemoglobin during drying. If a solution of oxyhemoglobin is frozen and dried, 20 to 30 per cent is changed to methemoglobin. Deoxygnated hemoglobin dried and preserved in vacuo retained all its oxygenbinding activity for 180 days, when stored at temperatures from 4° to 30°C. Storage at 38°C. for 92 days, or at 56° for 7 days, caused no loss in activity. The dried hemoglobin had a foam structure which caused it to dissolve immediately upon contact with water. Deoxygnated hemoglobin in the dry state was partly converted to methemoglobin by even momentary contact with oxygen. When, however, the deoxygnated hemoglobin was dissolved before it was exposed to air, the hemoglobin in solution was relatively stable, and could be stored for months at 4° in contact with air without significant loss of activity.

PREPARATION OF HEMOGLOBIN SOLUTIONS FOR INTRAVENOUS INFUSION

A procedure has been detailed for the preparation of sterile non-pyrogenic solutions of oxyhemoglobin which have the approximate protein content and electrolyte composition of plasma. Large volumes of solution can be rapidly prepared, with 95 to 98 per cent of the hemoglobin in the active form capable of combining with oxygen. The solutions contain no particulate matter; 95 per cent of total blood lipids are removed. Solutions stored at 4°C. showed no conversion of hemoglobin to methemoglobin over a period of 2½ months; over a 6 month period a small and variable amount of methemoglobin may be formed.

Bilateral subthalamic stimulation in Parkin and PINK1 parkinsonism

OBJECTIVES

To study the frequency of different gene mutations in patients with early-onset parkinsonism and bilateral subthalamic nucleus deep brain stimulation (STN-DBS) and the short- and long-term surgical outcome in mutation-positive (MUT+) and -negative (MUT-) patients.

METHODS

Eighty patients with disease onset at age <or= 45 years and bilateral STN-DBS were screened for mutations in the Parkin gene and PINK1 gene and for the recurrent p.G2019S mutation in the LRRK2 gene. The Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr (H-Y) scale were used to compare the on- and off-medication conditions preoperatively and in the off-medication/on-stimulation condition postoperatively.

RESULTS

We identified 12 mutation carriers (11 Parkin [6 with 2 mutated alleles, 5 with 1 mutated allele], 1 homozygous PINK1). There were no clinical differences between the MUT- and MUT+ patients preoperatively, except for more severe H-Y stage and postural and gait scores in the on-medication state in the MUT+ group. During the first year after surgery, MUT- patients showed better clinical improvement (56% motor UPDRS improvement) compared with MUT+ patients (36%). However, in the long-term follow-up (3-6 years), both groups presented with the same degree of clinical improvement (MUT-: 44% vs MUT+: 42%). Although the MUT+ group showed more severe axial signs preoperatively, MUT- patients developed levodopa- and deep brain stimulation-resistant axial signs within the first 3 to 6 years postoperatively, which diminished the initial benefit soon after surgery.

CONCLUSIONS

Patients with Parkin or PINK1 mutations benefit from subthalamic nucleus deep brain stimulation. However, the clinical response is not superior to non-mutation carriers and might be limited by more advanced axial motor symptoms at a relatively early disease stage.

Electrical high frequency stimulation of the caudate nucleus induces local GABA outflow in freely moving rats

Electrical high frequency stimulation of the globus pallidus internus or the subthalamic nucleus has beneficial motor effects in advanced Parkinson's disease. The mechanisms underlying these clinical results remain, however, unclear. From previous in vitro studies it is proposed that the gamma-aminobutyric acid (GABA) system is involved in the effectiveness of electrical high frequency stimulation (HFS). In these experiments, we developed an in vivo model that allows for simultaneous and collocated microdialysis and HFS by electrical pulses of 124 Hz in the caudate nucleus of freely moving rats. GABA and glutamate outflow were sampled by microdialysis technique and quantified after pre-column o-phthaldialdehyde sulphite derivatization using HPLC with electrochemical detection. As the most outstanding result, we could demonstrate that high frequency stimulation significantly increased basal GABA outflow without affecting glutamate levels in freely moving rats.

A systemic route for drug loading to lymphatic phagocytes

Lymph nodes are primary germination and proliferation sites for many types of pathogens. Maintaining therapeutic levels of appropriate chemotherapeutic agents in the lymph node tissue is critical for the treatment of both infection and cancer. This study was intended to develop a systemic route for loading lymph node phagocytes with drugs, using a lymph node specific nanocarrier. The latter is assembled as a 10-15 nm particle with a drug-carrying core and a phagocyte-homing poly(1-->6)-alpha-d-glucose based interface. Biokinetics and microdistribution of the model carrier were investigated in vivo. Nanocarrier accumulation in lymph nodes reached 30-35% dose/g in central lymph nodes, with deposition in various phagocytic cell populations. The latter included cells harboring inhaled microparticles translocated to lymph nodes from the lungs. In view of the nanocarrier ability to transport and release significant amounts of various drug substances, the data suggests feasibility of systemic drug loading to lymphatic phagocytes and, through drug release, to the neighboring cells.

Propacetamol and diclofenac alone and in combination for analgesia after elective tonsillectomy

BACKGROUND

Diclofenac and paracetamol have different mechanisms and sites of action. Therefore, we tested if their combination is more effective for analgesia after tonsillectomy than either drug alone with respect to rescue analgesic consumption and visual analog scale values.

METHODS

The analgesic effects of intravenously administered propacetamol (injectable pro-drug of paracetamol) and diclofenac or a combination on postoperative pain were compared in 71 adult elective tonsillectomy patients in a randomized, double-blind study. After induction of anesthesia the patients received monotherapy with 2 g propacetamol (n = 25) or 75 mg diclofenac (n = 25), or a combined treatment with 2 g propacetamol and 75 mg diclofenac (n = 21) in physiologic saline as an infusion. Postoperatively the propacetamol dosage was repeated twice and diclofenac once on the ward. Oxycodone (0.03 mg kg(-1)) was used as a rescue analgesic by patient-controlled analgesia.

RESULTS

On average the patients needed oxycodone 15.3, 13.2 and 10.6 times in the propacetamol, diclofenac and combination groups, respectively (NS). A verbal rating scale and a visual analog scale were employed for assessing post-tonsillectomy pain, nausea and patient satisfaction in all groups. No statistically significant differences were found between the groups. Twelve of the 25 (48%) patients having received propacetamol complained of pain at the cannulation site.

CONCLUSION

Combined treatment with propacetamol and diclofenac with the dosages used provided clinically only a minor advantage over monotherapy with propacetamol or diclofenac with respect to postoperative analgesia or the incidence of side-effects in adult tonsillectomy patients.

Synthesis of a Macromolecular Camptothecin Conjugate with Dual Phase Drug Release

A water soluble macromolecular conjugate of camptothecin (CPT) with a new, dual phase hydrolytic drug release mechanism was prepared on the basis of a 60 kDa biodegradable hydrophilic "stealth" polyacetal, poly(1-hydroxymethylethylene hydroxy-methyl formal). Succinamido-glycinate was used as a prodrug releasing group. A model preparation with 7.5% CPT content w/w was water soluble. The lipophilic camptothecin prodrug, camptothecin-(O20)-succinimidoglycinate, was released from the conjugate with t(1/2) = 2.2 +/- 0.1 h in rodent plasma. The blood clearance in a rodent model as measured by CPT was release limited, t(1/2) = 2.1 +/- 0.2 h, while the conjugate half-life was 14.2 +/- 1.7 h. In a xenograft tumor model, the conjugate demonstrated higher antineoplastic efficacy than CPT at a less than equitoxic dose. This improved therapeutic window is in line with the modified drug pharmacokinetics and with camptothecin release in a stabilized lipophilic prodrug form. Regulation of prodrug release and hydrolysis rates through linker structure modification will open the way to further improve both pharmacokinetics and pharmacodynamics.

New genes encoding subunits of a cytochrome bc1-analogous complex in the respiratory chain of the hyperthermoacidophilic crenarchaeon Sulfolobus acidocaldarius

The soxL gene from Sulfolobus acidocaldarius (DSM 639) encodes a Rieske iron-sulfur protein. In this study we report the identification of two open reading frames in its downstream region. The first one, named soxN, codes for a membrane protein bearing a resemblance to the b-type cytochromes of the cytochrome bc1 and b6f complexes. The protein is predicted to contain at least 10 transmembrane helices and features the two conserved histidine pairs coordinating the heme groups of these cytochromes. The second open reading frame, named odsN, encodes a soluble protein of unknown function. The genomic region displays a complex transcription pattern. Northern blot and RT-PCR analyses revealed the presence of mono- and bi-cistronic transcripts as well as a tri-cistronic transcript of soxL and cbsAB, encoding the mono-heme cytochrome b558/566. Phylogenetic analyses of the genes of the soxLN pair and of other archaeal gene pairs encoding Rieske iron-sulfur proteins and b-type cytochromes revealed an identical branching patterns for both protein families, suggesting an evolutionary link of these genes provided by the functional interaction of the proteins. On the basis of the findings of this study and the previously studied properties of the soxL and cbsA proteins, we propose the occurrence of a novel cytochrome bc1-analogous complex in the membranes of Sulfolobus, consisting of the cytochrome b homolog soxN, the Rieske protein soxL, the high potential cytochrome cbsA, as well as the non-redox-active subunits cbsB and odsN.

[Applications for a robot in the lateral skull base. Evaluation of robot-assisted mastoidectomy in an anatomic specimen]

In the past decade, a great variety of robot systems have been applied in numerous areas of life. In the public health system, robots are increasingly used in the operating theater. The potential for reproducibility and predictability was one of the main arguments for the use of robots in orthopedic treatment of bones, especially the implantation of a cementless total hip replacement. In otorhinolaryngological surgery (ENT), different hearing aids were developed: the cochlea implant for the deaf or the totally implantable hearing aid for the hearing impaired. Their site of implantation is localized in the lateral skull base. Removal of the bone mass with the reamer requires both great precision and considerable physical effort on the part of the surgeon, which does not result in an ergonomic operating technique. The following project describes the evaluation of processing parameters for a robot-assisted mastoidectomy to expose an implantation bed. The goal was to establish different parameters for robot-controlled reaming in the calotte or mastoid. In addition, several parameters were tested for their influence on surface structure, procedure reliability, and quality as well as the ability of the Mayfield clip to stabilize the head during the operation.

Synthesis of novel 2-azabicyclo[2.2.0]- and [2.1.1]hexanols

Methyl- and phenyl-substituted N-(ethoxycarbonyl)-2-azabicyclo[2.2.0]hex-5-enes 6 were reacted with NBS in wet DMSO to afford bromohydrins. Mixtures of unrearranged 6-exo-bromo-5-endo-hydroxy-2-azabicyclo[2.2.0]hexanes 7a,b and rearranged 5-anti-bromo-6-anti-hydroxy-2-azabicyclo[2.1.1]hexanes 8a,b were formed stereoselectively from the parent alkene 6a and 4-methyl alkene 6b. The 5-methyl alkene 6c affords only unrearranged bromohydrin 7c and dibromohydrin 9. By contrast, solely rearranged 3-endo-substituted-2-azabicyclo[2.1.1]hexane bromohydrins 8d-f result from additions to 3-endo-methyl alkene 6d, 3-endo-4-dimethyl alkene 6e, and 3-endo-phenyl alkene 6f. As an alternative route to bromohydrins, the parent 5,6-exo-epoxide 10a and 5-endo-methyl-5,6-exo-epoxide 10b were ring opened with bromine/triphenylphosphine to afford unrearranged 5-endo-bromo-6-exo-hydroxy-2-azabicyclo[2.2.0]hexanes 11a,b, while the 3-endo-methyl epoxide 10c afforded solely the rearranged 5-anti-bromo-6-anti-hydroxy-3-exo-methyl-2-azabicyclo[2.1.1]hexane isomer 8g. Tributyltin hydride reduction of bromohydrins 7a,b and 11a afforded novel 2-azabicyclo[2.2.0]hexan-5-ols 13a,b and -6-ol 14, and bromohydrins 8a,b, 8d-g afforded new 2-azabicyclo[2.1.1]-hexan-5-ols 15a,b and 15d-g.

Tracheal intubation after induction of anesthesia in children with propofol--remifentanil or propofol-rocuronium

PURPOSE

To compare the intubating conditions after remifentanil-propofol with those after propofol-rocuronium combination with the aim of determining the optimal dose of remifentanil.

METHODS

In a randomized, double-blind study 80 healthy children aged three to nine years were assigned to one of four groups (n=20): 2 or 4 microgxkg(-1) remifentanil (Re2 or Re4); 2 microgxkg(-1) remifentanil and 0.2 mgxkg(-1) rocuronium (Re2-Ro0.2); 0.4 mgxkg(-1) rocuronium (Ro0.4). After atropine, remifentanil was injected over 30 sec followed by 3.5 mgxkg(-1) propofol and rocuronium. After 60 sec, laryngoscopy and intubation were attempted. Intubating conditions were assessed as excellent, good or poor based on ease of ventilation, jaw relaxation, position of the vocal cords, and coughing to intubation.

RESULTS

In all children intubation was successful. Overall intubating conditions were better (P < 0.01), and the frequency of excellent conditions, 85%, was higher (P < 0.01) in the Re4 group than in the Ro0.4 group. No child manifested signs of muscular rigidity. In the remifentanil groups, arterial pressure decreased 11-13% and heart rate 6-9% after anesthetic induction, and remained at that level throughout the study.

CONCLUSION

The best intubating conditions were produced by the combination of 4 microgxkg(-1) remifentanil and 3.5 mgxkg(-1) propofol. It provided excellent or good intubating conditions in all children without causing undue cardiovascular depression.

Robot-assisted surgery system with kinesthetic feedback

The better understanding of the systems of the human body and their specific functions has led to minimally invasive and microsurgical procedures being carried out on an ever smaller scale. New therapies will require precision of 10 microm or better, which will only be achievable with robotic teleoperators. Experience with existing robot-assisted surgery systems shows that the human-machine interface is a critical component for acceptance of this technology, but no universally satisfactory interface has yet been found. Therefore, this article investigates a new concept based on kinesthetic motion feedback and presents details of the implementation of a first prototype.

A voice-controlled robotic assistant for neuroendoscopy

This paper describes experiments with a voice-controlled robot system to be used in endoscopic neurosurgery. The robot was a modified version of the robot described in previous publications of the group at Fraunhofer IPA and HSK. To control the robot a voice-controlled user interface was developed. The experiments were conducted on cadavers for three standard approaches in neuroendoscopy. The goal was to gain experience with a voice-controlled user interface and also with the set-up and use of the robotic system under clinical conditions. The results indicate that modifications to the robot and user interface are necessary. However the overall feasibility of the application was demonstrated.

Retigabine N-glucuronidation and its potential role in enterohepatic circulation

The metabolism of retigabine in humans and dogs is dominated by N-glucuronidation (), whereas in rats, a multitude of metabolites of this new anticonvulsant is observed (). The comparison of the in vivo and in vitro kinetics of retigabine N-glucuronidation in these species identified a constant ratio between retigabine and retigabine N-glucuronide in vivo in humans and dog. An enterohepatic circulation of retigabine in these species is likely to be the result of reversible glucuronidation-deglucuronidation reactions. Rats did not show such a phenomenon, indicating that enterohepatic circulation of retigabine via retigabine N-glucuronide does not occur in this species. In the rat, 90% of retigabine N-glucuronidation is catalyzed by UDP-glucuronosyltransferase (UGT)1A1 and UGT1A2, whereas family 2 UGT enzymes contribute also. Of ten recombinant human UGTs, only UGTs 1A1, 1A3, 1A4, and 1A9 catalyzed the N-glucuronidation of retigabine. From the known substrate specificities of UGT1A4 toward lamotrigine and bilirubin and our activity and inhibition data, we conclude that UGT1A4 is a major retigabine N-glucuronosyl transferase in vivo and significantly contributes to the enterohepatic cycling of the drug.

Transient neurological symptoms after spinal anaesthesia with hyperbaric 5% lidocaine or general anaesthesia

Transient neurotoxicity of concentrated local anaesthetics has been thought to be the main reason for transient neurological symptoms after spinal anaesthesia. Profound musculoligamental relaxation by high doses of local anaesthetics may contribute to the development of postoperative musculoskeletal pain. In order to evaluate the role of the loss of strength of the supportive structures of the spine in the development of transient neurological symptoms, 60 patients (ASA I-II) undergoing minor orthopaedic, varicose vein or inguinal hernia operations were allocated randomly to receive spinal anaesthesia with hyperbaric lidocaine 50 mg ml-1 (85-100 mg) or balanced general anaesthesia with neuromuscular block. Patients were interviewed 24 h later and after 1 week they returned a written questionnaire. Transient neurological symptoms, consisting of pain in the buttocks or pain radiating symmetrically to the lower extremities, occurred in eight patients (27%) receiving spinal anaesthesia and in one patient (3%) receiving general anaesthesia (P < 0.05). We conclude that a transient neurotoxic effect of hyperbaric lidocaine 50 mg ml-1 is probably the main reason for transient neurological symptoms after spinal anaesthesia but musculoligamental relaxation may contribute to the development of low back or leg pain after both anaesthetic techniques.

Encapsulation of the topoisomerase I inhibitor GL147211C in pegylated (STEALTH) liposomes: pharmacokinetics and antitumor activity in HT29 colon tumor xenografts

The topoisomerase I inhibitor GL147211C [7-[(4-methylpiperazino)methyl]-10,11-(ethylenedioxy)-(20S)-campto thecin trifluoroacetate], a camptothecin analogue, has significant activity in tumor cell cytotoxicity assays in vitro and antitumor activity in both animal tumor models and human patients. Its toxicity is significant, however, effectively limiting the amount of drug that can be administered and its clinical utility. To determine whether the therapeutic index of GL147211C could be improved, the drug was encapsulated in long-circulating, pegylated (STEALTH) liposomes (SPI-355). The pharmacokinetics and antitumor activity of SPI-355 were compared to those of nonliposomal GL147211C. The plasma pharmacokinetics of SPI-355 in rats were typical of those of other pegylated liposomal formulations, with significantly increased blood circulation time; the dose-corrected area under the curve and Cmax of SPI-355 (10 mg/kg) were 1250- and 35-fold higher, respectively, than those of nonliposomal GL14711C (8.72 mg/kg). The comparative antitumor activity of SPI-355 and nonliposomal GL1472211C was evaluated in nude mice implanted with HT29 colon carcinoma xenografts. SPI-355 was 20-fold more effective than GL147211C in inhibiting tumor growth (1 mg/kg SPI-355 and 20 mg/kg GL147211C) and produced durable complete remissions of tumors at well-tolerated dose levels that were >5-fold lower than the maximally tolerated dose of GL147211C, which induced no durable complete responses. Signs of toxicity were similar between the two drugs, but liposome encapsulation increased the toxicity of drug approximately 4-fold, with increased weight loss and several deaths with SPI-355 (5 mg/kg SPI-355 versus 20 mg/kg GL147211C). Despite the increased toxicity seen with SPI-355, the therapeutic index of the liposomal formulation was increased approximately 5-fold over that of nonliposomal GL147211C, suggesting that such a pegylated liposomal formulation could demonstrate increased therapeutic index in human patients.

Transient neurological symptoms after spinal anaesthesia with 4% mepivacaine and 0.5% bupivacaine

Several studies have reported transient neurological symptoms after spinal anaesthesia with 5% lignocaine. In order to evaluate the role of concentrated solutions of local anaesthetic in the development of transient neurological symptoms, 200 ASA I or II patients undergoing minor orthopaedic or rectal surgery under spinal anaesthesia were allocated randomly to receive 4% mepivacaine 80 mg or hyperbaric 0.5% bupivacaine 10 mg. All patients were interviewed by an anaesthetist approximately 24 h after spinal anaesthesia, and after 1 week patients were asked to return a written questionnaire. The incidence of transient neurological symptoms consisting of pain in the buttocks or pain radiating symmetrically to the lower extremities differed (P < 0.001) between patients receiving mepivacaine (30%) and those receiving bupivacaine (3%). Hyperbaric 0.5% bupivacaine can be recommended for minor operations on the lower abdomen or lower extremities.

Isotope anomalies of carbon, hydrogen and nitrogen in peat from the area of the tunguska cosmic body explosion (1908)

Abstract Peat profiles from the area of the Tunguska explosion epicentre indicate significant carbon and hydrogen isotopic effects which are clearly associated with the zone of the 1908 "catastrophe", and which cannot be attributed to any known terrestrial processes. We explain them with the presence of extraterrestrial matter similar to carbonaceous chondrites or, more probably, to cometary matter. Initial data on nitrogen content and its isotope composition are consistent with the assumption of acid rainfall following the passage and explosion of the Tunguska cosmic body, as is known to have occurred during the Cretaceous-Tertiary boundary.

Comparison of cardiovascular changes during anaesthesia and recovery from propofol-alfentanil-nitrous oxide and thiopentone-halothane-nitrous oxide anaesthesia in children undergoing otolaryngological surgery

Propofol/alfentanil anaesthesia was compared with thiopentone/halothane anaesthesia in 86 midazolam-atropine premedicated children undergoing minor otolaryngological surgery. The study was randomised, and evaluation of recovery from anaesthesia was double-blind. The children were divided into two age groups: 1-3 years and 4 years and older. Particular attention was paid to ECG changes during anaesthesia and to the rapidity of recovery. One minute after alfentanil 15 micrograms.kg-1, the children in the propofol group received propofol 2.0-3.0 mg.kg-1 followed by propofol infusion 15 mg.kg-1.h-1. In addition, 0.1% suxamethonium 6 mg.kg-1.h-1 was infused during operation. The other children received thiopentone 5-7 mg.kg-1 followed by halothane (0.5-2%) immediately after endotracheal intubation. Junctional rhythm occurred in 5-35% of the children independent of anaesthesia method, and ventricular ectopic beats were seen in 20% of the older children during halothane anaesthesia. Recovery with respect to times to eye opening or response to verbal contact was significantly faster after propofol/alfentanil anaesthesia than after thiopentone/halothane anaesthesia in the older but not in the younger age group. Furthermore, in the younger age group significantly more crying occurred after propofol/alfentanil than after thiopentone/halothane anaesthesia. On the basis of this study, thiopentone/halothane anaesthesia is recommended for children aged 1-3 years and propofol/alfentanil anaesthesia for older children undergoing adenoidectomy and/or tonsillectomy.

Tracheal intubation after induction of anaesthesia with propofol, alfentanil and lidocaine without neuromuscular blocking drugs in children

In a double-blind study, intubating conditions and haemodynamic responses were assessed in two age-groups of 45 ASA I-II children, with mean ages of 2.4 and 6.3 years, premedicated with oral midazolam and atropine. The children were randomly allocated to one of three groups: alfentanil 20 micrograms.kg-1 + lidocaine 1 mg.kg-1 (Alf20 + Lign); alfentanil 20 micrograms.kg-1 (Alf20); or alfentanil 40 micrograms.kg-1 (Alf40), followed by propofol 3.5 mg.kg-1 in the children aged 1-3 years and 3.0 mg.kg-1 in the older children. Intubating conditions, 40 s after the administration of propofol, were assessed as good, moderate or impossible on the basis of jaw relaxation, ease of insertion of the endotracheal tube and coughing during intubation. In the younger age group the frequencies of good, moderate or impossible intubating conditions were 87, 13 and 0% in the Alf40, 40, 60 and 0% in the Alf20 (P < 0.05 compared to the Alf40 group) and 53, 47 and 0% in the Alf20 + Lign group. In the older age group the corresponding frequencies were 60, 33 and 7% in the Alf20 + Lign, 47, 53 and 0% in the Alf20 and 47, 40 and 13% in the Alf40 group. All the drugs prevented any increase in arterial pressure and heart rate after tracheal intubation. The QTc interval of the ECG was always in the normal range. Clinically important bradycardia did not occur. In conclusion, the best intubating conditions occurred after propofol 3.5 mg.kg-1 and alfentanil 40 micrograms.kg-1 in the younger age group.(ABSTRACT TRUNCATED AT 250 WORDS)