Identification of an inhibitory pocket in falcilysin provides a new avenue for malaria drug development

Identification of new druggable protein targets remains the key challenge in the current antimalarial development efforts. Here we used mass-spectrometry-based cellular thermal shift assay (MS-CETSA) to identify potential targets of several antimalarials and drug candidates. We found that falcilysin (FLN) is a common binding partner for several drug candidates such as MK-4815, MMV000848, and MMV665806 but also interacts with quinoline drugs such as chloroquine and mefloquine. Enzymatic assays showed that these compounds can inhibit FLN proteolytic activity. Their interaction with FLN was explored systematically by isothermal titration calorimetry and X-ray crystallography, revealing a shared hydrophobic pocket in the catalytic chamber of the enzyme. Characterization of transgenic cell lines with lowered FLN expression demonstrated statistically significant increases in susceptibility toward MK-4815, MMV000848, and several quinolines. Importantly, the hydrophobic pocket of FLN appears amenable to inhibition and the structures reported here can guide the development of novel drugs against malaria.

Prescribing Patterns of Codeine and Alternative Medicines in Children in Europe

Introduction

Concerns over serious respiratory depression in children led to two European Union (EU) referral procedures (in 2013 and 2015) to review the benefit–risk balance of codeine in this population when used for pain relief, cough or cold. Consequently, codeine should no longer be used in children aged < 12 years and restrictions were introduced for treatment in children ≥ 12 years.

Objective

This multinational collaborative study aimed to assess the effectiveness of these risk minimisation measures by evaluating changes in prescribing of codeine and alternative treatments.

Method

Children under 12 and 12–18 years old were followed between 2010 and 2017 to analyse quarterly trends in prescribing of codeine and alternative treatments in electronic health records from France, Germany, Norway, Spain and the United Kingdom using interrupted time series analysis.

Results

Overall prescribing of codeine in children decreased in all five countries, reaching near zero prevalence in children under 12 years of age. This was accompanied by an increase in use of other opioid analgesics in France (from 0.15 to 0.56 prevalence per 100 person-years immediately after the first referral), Norway (from 0.0006 to 0.0013 at the end of the study), the United Kingdom (from 0.018 to 0.05 at the end of the study), and an increase in non-opioid analgesics in Norway (from 0.045 to 0.075 at the end of the study) after the referral on pain relief indication. The referral on cough/cold indication led to a decrease in use of opioid and non-opioid antitussives in children aged < 12 years in France (from 10 to 7 and 20 to 16, respectively) and had no impact in other countries. Overall prescribing trends for codeine and alternatives were similar across both age groups within each country.

Conclusion

The decrease in use of codeine shows that healthcare professionals followed the adopted measures and switched prescribing practices for pain management in children aged < 18 years towards opioid or non-opioid analgesics depending on national clinical and reimbursement settings. Whist the magnitude of the first referral on pain differed between countries, the second referral on cough/cold had only a minimal impact on the use of codeine and antitussives.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-022-01214-y.

Extra-Articular Hip Resection and Reconstruction with Custom Acetabular Resection Guide and Implants in a Case of High-Grade Spindle Cell Sarcoma of the Proximal Femur: A Case Report

CASE

A 29-year-old man was admitted with acute atraumatic left hip pain and inability to bear weight. Subsequent workup revealed an intracapsular pathologic fracture of the femoral neck secondary to a high-grade spindle cell sarcoma. A unique method of extra-articular resection and reconstruction using a 3-dimensional (3D)-printed custom cutting jig and a custom acetabular component was pursued. Wide margins were achieved without violating the joint capsule but preserving pelvic integrity, allowing a return to an active lifestyle.

CONCLUSION

Three-dimensional-printed custom resection guides and implants can help achieve adequate resection margins while preserving pelvic integrity and function.

LiQD Cornea: Pro-regeneration collagen mimetics as patches and alternatives to corneal transplantation

Transplantation with donor corneas is the mainstay for treating corneal blindness, but a severe worldwide shortage necessitates the development of other treatment options. Corneal perforation from infection or inflammation is sealed with cyanoacrylate glue. However, the resulting cytotoxicity requires transplantation. LiQD Cornea is an alternative to conventional corneal transplantation and sealants. It is a cell-free, liquid hydrogel matrix for corneal regeneration, comprising short collagen-like peptides conjugated with polyethylene glycol and mixed with fibrinogen to promote adhesion within tissue defects. Gelation occurs spontaneously at body temperature within 5 min. Light exposure is not required-particularly advantageous because patients with corneal inflammation are typically photophobic. The self-assembling, fully defined, synthetic collagen analog is much less costly than human recombinant collagen and reduces the risk of immune rejection associated with xenogeneic materials. In situ gelation potentially allows for clinical application in outpatient clinics instead of operating theaters, maximizing practicality, and minimizing health care costs.

Below Chance Performance of p < .05 or p < .20: Frequency of Statistically Below Chance Scores in Dementia

Objective

A p-value of < .05 has traditionally been utilized to determine below chance performance on forced-choice performance validity tests (PVT). Recently, Binder and colleagues (2014 & 2018) proposed that the p-value cutoff increase to < .20. To ensure this does not result in frequent false-positive errors in patients who are likely to have significant cognitive impairment, frequency of below chance scores at both p-values were examined within the context of possible dementia.

Method

Archival data of cognitively impaired inpatient (n = 55; mean RBANS Total Score = 64.67) and outpatient (n = 203; mean RBANS Total Score = 74.15) older adults without external incentives were examined to determine frequency of below chance performances on the Coin-in-the-Hand Test. To supplement this data and examine below chance performance on a second PVT, the authors reviewed empirical literature and extracted data on TOMM performance in individuals with dementia. Four studies (n = 269 patients) provided data that could be extracted.

Results

No patient produced a Coin-in-the-Hand Test score (0/258 individuals) reaching either p value cutoff. Similarly, no patient produced a TOMM Trial 2 (0/121 individuals) or Retention score (0/84 individuals) reaching either p value cutoff. For TOMM Trial 1, no patient (0/44) scored at p < .05 but two patients (2/64) scored at p < .20.

Conclusions

No individual in this study produced scores on either PVT reaching the p < .05 cutoff. At the p < .20 cutoff, there were only 2 out of 527 performances (0.4%) that reached this threshold; both of which were observed on TOMM Trial 1. This data supports the recommendation that p < .20 be used when determining below chance performance.

Ciguatoxin prevalence in 4 commercial fish species along an oceanic exposure gradient in the US Virgin Islands

Ciguatera fish poisoning is a seafood-toxin illness resulting from consumption of fish contaminated with ciguatoxins. Managing ciguatera fish poisoning is complex. It is made easier, however, by local fishers from endemic areas reporting regional predictability for local fish species' ciguatera fish poisoning risk, which the present study then tested. We investigated the prevalence of ciguatoxins in 4 commonly marketed and consumed species (Balistes vetula, Haemulon plumierii, Ocyurus chrysurus, and Epinephelus guttatus) across an oceanic gradient (north, south, east, and west) from the US Virgin Islands. Fish muscle extracts were analyzed for Caribbean ciguatoxins using an in vitro mouse neuroblastoma (N2a) cytotoxicity assay and confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Fish collected from the north location had 0 fish with detectable ciguatoxins; this site also had the greatest wave energy. Caribbean ciguatoxins in fish ranged from 0.01 to 0.11, 0.004 to 0.10, and 0.005 to 0.18 ng Caribbean ciguatoxin-1 eq/g, from the west, east, and south respectively. Ciguatoxin-like activity was detectable by the N2a assay in 40, 41, 50, and 70% of H. plumierii, O. chrysurus, B. vetula, and E. guttatus, respectively. Of the fish collected, 4% had Caribbean ciguatoxin levels exceeding the US Food and Drug Administration guidance of 0.1 ng Caribbean ciguatoxin-1 eq/g fish. These findings concurred with spatial ciguatera fish poisoning prevalence information provided by local fishers in the US Virgin Islands and demonstrate how partnerships between researchers and fishers can aid the improvement of science-based ciguatera fish poisoning management. Environ Toxicol Chem 2018;39:1852-1863. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Genetic relationships between boar feed efficiency and sow piglet production, body condition score, and stayability in Norwegian Landrace pigs

Both feed efficiency and sow production are economically important traits in pig breeding. One challenge in a maternal line such as Norwegian Landrace is to breed for highly feed efficient fattening pigs and, at the same time, produce sows with high daily feed intake to maintain their BCS in multiple parities. The aim of this study was to estimate genetic correlations among novel feed efficiency measurements on Norwegian Landrace boars and piglet production, stayability, and body condition in Norwegian Landrace sows. The feed efficiency measurements were lean meat and fat efficiency. These measurements were calculated using an extended residual feed intake model where total feed intake in the test period was the response variable and fat (kg) and lean meat (kg) on the carcass were included as both fixed and random regressions. The random regression coefficients that resulted from this model were breeding values, which represented the amount of feed used to produce an extra kilogram of lean meat and fat. The sow traits were stayability of the sow from first to second parity, BCS at weaning, litter weight at 3 wk, and total number of piglets born. All traits were recorded on first parity purebred Norwegian Landrace and analyzed using multivariate animal models. All genetic correlations between fat efficiency and sow traits were low. Significant genetic correlations were found only between fat efficiency and stayability (0.21 ± 0.11) and between fat efficiency and total litter weight at 3 wk (0.21 ± 0.10). The results indicate that selection for efficient deposition of fat could give poor stayability and lower litter weight at 3 wk in first parity sows. The genetic correlations between lean meat efficiency and sow traits were not significantly different from 0 and signified no genetic relationships between these traits. Selection for efficient deposition of lean meat should not affect the sow traits and is, therefore, beneficial.

Endovascular Repair of AAA Rupture 20 Months after Endoluminal Stent-Grafting

Purpose:

To demonstrate the feasibility of endovascular repair of a ruptured abdominal aortic aneurysm (AAA) previously treated with an endoluminal stent-graft.

Case Report:

An 84-year-old man with a 9.5-cm AAA underwent endoluminal repair with an Endologix stent-graft, but a type I endoleak was detected postprocedurally. The patient was discharged and lost to follow-up. Twenty months later, he suffered an aneurysm rupture, which was repaired using endovascular techniques. Although he had a postoperative course complicated by aspiration pneumonia and renal failure, he recovered fully and was discharged from the hospital with no evidence of endoleak on the postprocedural imaging studies.

Conclusions:

Late ruptures after endoluminal AAA stent-grafting can be successfully treated with endovascular techniques.

Inadvertent Prolonged Femoral Nerve Palsy After Field Block with Liposomal Bupivacaine for Inguinal Herniorrhaphy

Inguinal herniorrhaphy is a common outpatient procedure where analgesia can be augmented with local infiltration. We report a case of prolonged femoral nerve palsy secondary to liposomal bupivacaine use during wound infiltration after inguinal herniorrhaphy. Inadvertent transient femoral nerve palsy is a rare but known complication after ilioinguinal field block. This case both highlights the value of ultrasound imaging in evaluating the complications and demonstrates how the prolonged nature of liposomal bupivacaine can prolong adverse sequela.

2'-Modified Guanosine Analogs for the Treatment of HCV

Novel 2'-modified guanosine nucleosides were synthesized from inexpensive starting materials in 7-10 steps via hydroazidation or hydrocyanation reactions of the corresponding 2'-olefin. The antiviral effectiveness of the guanosine nucleosides was evaluated by converting them to the corresponding 5'-O-triphosphates (compounds 38-44) and testing their biochemical inhibitory activity against the wild-type NS5B polymerase.

Self-assembled collagen-like-peptide implants as alternatives to human donor corneal transplantation

PEG-conjugated collagen-like peptides promote corneal regeneration in a pig cornea.

Oxabicyclooctane-linked novel bacterial topoisomerase inhibitors as broad spectrum antibacterial agents

Bacterial resistance is eroding the clinical utility of existing antibiotics necessitating the discovery of new agents. Bacterial type II topoisomerase is a clinically validated, highly effective, and proven drug target. This target is amenable to inhibition by diverse classes of inhibitors with alternative and distinct binding sites to quinolone antibiotics, thus enabling the development of agents that lack cross-resistance to quinolones. Described here are novel bacterial topoisomerase inhibitors (NBTIs), which are a new class of gyrase and topo IV inhibitors and consist of three distinct structural moieties. The substitution of the linker moiety led to discovery of potent broad-spectrum NBTIs with reduced off-target activity (hERG IC50 > 18 μM) and improved physical properties. AM8191 is bactericidal and selectively inhibits DNA synthesis and Staphylococcus aureus gyrase (IC50 = 1.02 μM) and topo IV (IC50 = 10.4 μM). AM8191 showed parenteral and oral efficacy (ED50) at less than 2.5 mg/kg doses in a S. aureus murine infection model. A cocrystal structure of AM8191 bound to S. aureus DNA-gyrase showed binding interactions similar to that reported for GSK299423, displaying a key contact of Asp83 with the basic amine at position-7 of the linker.

Effect of Surgical Technique on Corneal Implant Performance

PURPOSE

Our aim was to determine the effect of a surgical technique on biomaterial implant performance, specifically graft retention.

METHODS

Twelve mini pigs were implanted with cell-free, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) cross-linked recombinant human collagen type III (RHCIII) hydrogels as substitutes for donor corneal allografts using overlying sutures with or without human amniotic membrane (HAM) versus interrupted sutures with HAM. The effects of the retention method were compared as well as the effects of collagen concentration (13.7% to 15% RHCIII).

RESULTS

All implanted corneas showed initial haze that cleared with time, resulting in corneas with optical clarity matching those of untreated controls. Biochemical analysis showed that by 12 months post operation, the initial RHCIII implants had been completely remodeled, as type I collagen, was the major collagenous protein detected, whereas no RHCIII could be detected. Histological analysis showed all implanted corneas exhibited regeneration of epithelial and stromal layers as well as nerves, along with touch sensitivity and tear production. Most neovascularization was seen in corneas stabilized by interrupted sutures.

CONCLUSIONS

This showed that the surgical technique used does have a significant effect on the overall performance of corneal implants, overlying sutures caused less vascularization than interrupted sutures.

TRANSLATIONAL RELEVANCE

Understanding the significance of the suturing technique can aid the selection of the most appropriate procedure when implanting artificial corneal substitutes. The same degree of regeneration, despite a higher collagen content indicates that future material development can progress toward stronger, more resistant implants.

Surgical wound morbidity in an austere surgical environment

Surgical wound morbidity was analyzed for a U.S. military field hospital deployed to the Republic of Haiti in support of Operation New Horizons 1998. The purpose of the analysis was to determine whether procedures performed in the field hospital had greater infectious risks as a result of the environment compared with historical reports for traditional hospital or clinic settings. Acceptable historical infection rates of 1.5% for clean surgical cases, 7.7% for clean contaminated cases, 15.2% for contaminated cases, and 40% for dirty cases have been noted. There were 827 operations performed during a 6-month period, with the majority of patients assigned American Society of Anesthesiologists (ASA) Physical Status Classification class I or II. The distribution of these cases was: 72% clean cases, 5% clean contaminated cases, 4% contaminated cases, and 19% dirty cases. The overall wound complication rate was 3.6%, which included 5 wound infections, 11 wound hematomas, 8 superficial wound separations, and 6 seromas. The infectious morbidity for clean cases, the index for evaluation of infectious complications, was 0.8%, well within the accepted standards. There were two major complications that required a return to the operating room: a wound dehiscence with infection in an orchiectomy and a postoperative hematoma with airway compromise in a subtotal thyroidectomy. There were no surgical mortalities. The infectious wound morbidity for operations performed in the field hospital environment was found to be equivalent to that described for the fixed hospital or clinic settings. No special precautions were necessary to ensure a low infection rate. The safety for patients undergoing elective surgical procedures has been established. Further training using these types of facilities should not be limited based on concerns for surgical wound morbidity.

Treatment related changes of the serum epidermal growth factor receptor in advanced colorectal cancer

e22096

Background: The epidermal growth factor receptor (EGFR) is an established target for therapy in colorectal cancer. The extracellular domain of the receptor is shed into circulation and detectable by ELISA. We investigated the changes in sEGFR levels during preoperative chemoradiation (CRT) in rectal cancer patients and third-line treatment with cetuximab and irinotecan (CETIRI) in advanced disease, to elucidate the predictive or prognostic value in these settings. Methods: We included 126 healthy controls and 118 patients with chemorefractory mCRC treated with cetuximab (initial 400/m2 mg followed by weekly 250mg/m2) and irinotecan (350 mg/m2 q3w). Response was evaluated according to RECIST. Furthermore, 114 patients with locally advanced rectal tumours were treated with CRT (60 Gy/30 fractions and concomitant uftoral (300 mg/m2)/leukovorin (22.5 mg) on treatment days, followed by surgery 8 weeks post-treatment and pathological tumour regression evaluation. Pre-treatment and consecutive samples were drawn at each visit. sEGFR was measured by ELISA. Median statistics and Kaplain-Mayer curves with log-rank testing for comparison of survival rates were performed. Results: There were significant differences between the median pre-treatment sEGFR levels in controls, rectal cancer and mCRC (58 ng/ml(56–59 95% C-I), 53 ng/ml(51–55 95% C-I) and 51 ng/ml(49–53 95% C-I), respectively, p<0.000). We detected a rapid increase in sEGFR by the first on- treatment values during CETIRI (p<0.001), and a correlation between the magnitude of increase and a higher degree of skin toxicity, a well known indicator of clinical benefit to EGFR inhibitors. sEGFR in rectal cancer patients displayed a decreasing tendency during CRT (p<0.001), but no correlation to local tumour response. Patients with baseline pre-treatment level > 43.4 ng/ml (mean sEGFR of control group-2xSD) had a significantly higher OS rate than patients with low baseline levels (93% and 59% respectively, HR 0.15, P=0.002). Conclusions: We report a rapid increase in sEGFR by the onset of CETIRI, which may indicate development of skin toxicity and thereby a better change of response. Furthermore, we suggest a potential prognostic value of sEGFR measurement during CRT in locally advanced rectal cancer.

No significant financial relationships to disclose.

The structure, stability, and complex behavior of recombinant human gelatins

Gelatin prepared from animal sources is widely used as a stabilizer in vaccine formulations. The disadvantages associated with their use such as heterogeneity and allerginicity, have led to the development of recombinant human gelatins (rhGs) as a substitute. This study focuses on characterizing the structure and monitoring the physical stability of four molecular weights ( approximately 8.5, 25, 50, and 100 kDa) of rhGs as a function of temperature and pH. The information supplied should be useful in predicting the behavior of rhGs under formulation conditions. A number of spectroscopic techniques were employed in this study. Experimental results indicated that the solution properties of all four rhGs were unpredictable with micro-aggregation observed at various pH values. The 8.5 kDa rhG was found to be in a micro-aggregated state at pH 5 while the 25 kDa rhG was found to be more aggregated at pHs 5, 7, and 8. The properties of these aggregates have been analyzed as a function of temperature. The rhGs were also found to complex with the polyanion heparin through electrostatic and nonelectrostatic interactions. The stability of these complexes has been studied as a function of temperature and pH.

Stabilization of proteins by recombinant human gelatins

Porcine gelatins have been widely used as stabilizers of macromolecular based pharmaceuticals but the mechanism by which they stabilize has not been precisely established. Their variability and immunogenicity, however, make them less than ideal excipients. In this work, we take advantage of the availability of recombinant human gelatins (rhGs) to explore the mechanism by which they may stabilize proteins. Three model recombinant proteins, human serum albumin (HSA), bovine granulocyte colony stimulating factor (bGCSF), and human fibroblast growth factor-20 (FGF-20) that display a range of isoionic points have been selected for this study. The interaction of these model proteins with four different molecular weight rhGs and porcine gelatin was studied using a variety of biophysical techniques including fluorescence, CD and second derivative UV spectroscopy to monitor tertiary and secondary structure as a function of temperature. The 8.5, 25, and 100 kDa rhGs had the greatest effect on conformational and colloidal stability of HSA. The 8.5, 25, and 50 kDa rhGs also increased the T(0) of aggregation of bGCSF and FGF-20. Experiments to probe the mechanism of interaction of model proteins with rhGs suggest that the rhGs might interact with the partially unfolded states of target proteins through a combination of electrostatic and other intermolecular mechanisms to inhibit aggregation.

Changes in metabolic parameters with switching to aripiprazole from another second-generation antipsychotic: a retrospective chart review

OBJECTIVE

This is a retrospective chart review of psychiatric outpatients switched to aripiprazole from another second-generation antipsychotic (SGA) examining whether metabolic parameters improved after the switch.

METHOD

Twenty-four psychiatric outpatients who had been switched to aripiprazole from another SGA were evaluated. Data were collected from October 6, 2004, until February 25, 2005, through review of medical records. Laboratory values and physical data were extracted to assess levels of fasting blood glucose, triglycerides, total cholesterol, high-density lipoproteins (HDL), low-density lipoproteins (LDL), and weight.

RESULTS

After switching to aripiprazole, total cholesterol was significantly decreased, with a mean (SD) difference of -28.8 (32.1) mg/dL (p = .001), and LDL was significantly decreased, with a mean (SD) difference of -20.75 (21.7) mg/dL (p = .0017). Weight was also significantly decreased, with a mean (SD) difference of -11.7 (16.6) lb (p = .003). There were no significant differences in HDL, triglycerides, or fasting blood glucose. When a subgroup of 15 patients switched from olanzapine to aripiprazole was examined separately, these changes were even more robust. In this subgroup, total cholesterol was significantly decreased, with a mean (SD) difference of -32.0 (35.6) mg/dL (p = .01). LDL was significantly decreased, with a mean (SD) difference of -21.6 (24.7) mg/dL (p = .011), and weight was significantly decreased, with a mean (SD) difference of -16.7 (14.7) lb (p < .001). Changes in total cholesterol, LDL, and HDL were not significantly different between subjects taking lipid-lowering medications and those not taking them.

CONCLUSION

Psychiatric outpatients switched to aripiprazole from another SGA showed a decrease in weight, total cholesterol, and LDL. Switching to aripiprazole, when clinically indicated, may lead to improvement in metabolic parameters associated with cardiovascular disease.

Evaluation of a recombinant human gelatin as a substitute for a hydrolyzed porcine gelatin in a refrigerator-stable Oka/Merck live varicella vaccine

Background

The labile nature of live, attenuated varicella-zoster virus (Oka/Merck) requires robust stabilization during virus bulk preparation and vaccine manufacturing in order to preserve potency through storage and administration. One stabilizing ingredient used in a varicella-zoster virus (VZV) vaccine is hydrolyzed porcine gelatin which represents the major protein/peptide-based excipient in the vaccine formulation.

Methods

In this comparative study, a recombinant human gelatin fragment (8.5 kD) was assessed as a potential replacement for hydrolyzed porcine gelatin in an experimental live, attenuated VZV (Oka/Merck) vaccine. VZV (Oka/Merck) was harvested in two formulations prepared with either a hydrolyzed porcine gelatin or a recombinant human gelatin. Moreover, the viral stability in the experimental VZV (Oka/Merck) vaccines was evaluated under accelerated and real-time conditions in a comparative study.

Results and discussion

The stabilizing effect of recombinant human gelatin on VZV (Oka/Merck) potency change during vaccine lyophilization was similar to the experimental vaccine containing porcine-derived gelatin. Vaccine viral potency changes were comparable in stabilized VZV (Oka/Merck) formulations containing either hydrolyzed porcine gelatin or recombinant human gelatin. No statistically significant difference in potency stability was observed between the vaccine formulations stored at any of the temperatures tested.

Conclusion

The recombinant human gelatin demonstrated similar ability to stabilize the live attenuated VZV (Oka/Merck) in an experimental, refrigerator-stable varicella vaccine when compared to the vaccine preparation formulated with hydrolyzed porcine gelatin used in currently marketed varicella vaccine.

Decline eccentric squats increases patellar tendon loading compared to standard eccentric squats

BACKGROUND

Recent studies have shown excellent clinical results using eccentric squat training on a 25 degrees decline board to treat patellar tendinopathy. It remains unknown why therapeutic management of patellar tendinopathy using decline eccentric squats offer superior clinical efficacy compared to standard horizontal eccentric squats. This study aimed to compare electromyography activity, patellar tendon strain and joint angle kinematics during standard and decline eccentric squats.

METHODS

Thirteen subjects performed unilateral eccentric squats on flat-and a 25 degrees decline surface. During the squats, electromyography activity was obtained in eight representative muscles. Also, ankle, knee and hip joint goniometry was obtained. Additionally, patellar tendon strain was measured in vivo using ultrasonography as subjects maintained a unilateral isometric 90 degrees knee angle squat position on either flat or 25 degrees decline surface.

FINDINGS

Patellar tendon strain was significantly greater (P<0.05) during the squat position on the decline surface compared to the standard surface. The stop angles of the ankle and hip joints were significantly smaller during the decline compared to the standard squats (P<0.001, P<0.05). Normalized mean electromyography amplitudes of the knee extensor muscles were significantly greater during the decline compared to the standard squats (P<0.05). Hamstring and calf muscle mean electromyography did not differ, respectively, between standard and decline squats.

INTERPRETATION

The use of a 25 degrees decline board increases the load and the strain of the patellar tendon during unilateral eccentric squats. This finding likely explains previous reports of superior clinical efficacy of decline eccentric squats in the rehabilitative management of patellar tendinopathy.

Recombinant microbial systems for the production of human collagen and gelatin

The use of genetically engineered microorganisms is a cost-effective, scalable technology for the production of recombinant human collagen (rhC) and recombinant gelatin (rG). This review will discuss the use of yeast (Pichia pastoris, Saccharomyces cerevisiae, Hansenula polymorpha) and of bacteria (Escherichia coli, Bacillus brevis) genetically engineered for the production of rhC and rG. P. pastoris is the preferred production system for rhC and rG. Recombinant strains of P. pastoris accumulate properly hydroxylated triple helical rhC intracellularly at levels up to 1.5 g/l. Coexpression of recombinant collagen with recombinant prolyl hydroxylase results in the synthesis of hydroxylated collagen with thermal stability similar to native collagens. The purified hydroxylated rhC forms fibrils that are structurally similar to fibrils assembled from native collagen. These qualities make rhC attractive for use in many medical applications. P. pastoris can also be engineered to secrete high levels (3 to 14 g/l ) of collagen fragments with defined length, composition, and physiochemical properties that serve as substitutes for animal-derived gelatins. The replacement of animal-derived collagen and gelatin with rhC and rG will result in products with improved safety, traceability, reproducibility, and quality. In addition, the rhC and rG can be engineered to improve the performance of products containing these biomaterials.

Expression and characterization of a low molecular weight recombinant human gelatin: development of a substitute for animal-derived gelatin with superior features

Gelatin is used as a stabilizer in several vaccines. Allergic reactions to gelatins have been reported, including anaphylaxis. These gelatins are derived from animal tissues and thus represent a potential source of contaminants that cause transmissible spongiform encephalopathies. We have developed a low molecular weight human sequence gelatin that can substitute for the animal sourced materials. A cDNA fragment encoding 101 amino acids of the human proalpha1 (I) chain was amplified, cloned into plasmid pPICZalpha, integrated into Pichia pastoris strain X-33, and isolates expressing high levels of recombinant gelatin FG-5001 were identified. Purified FG-5001 was able to stabilize a live attenuated viral vaccine as effectively as porcine gelatin. This prototype recombinant gelatin was homogeneous with respect to molecular weight but consisted of several charge isoforms. These isoforms were separated by cation exchange chromatography and found to result from a combination of truncation of the C-terminal arginine and post-translational phosphorylation. Site-directed mutagenesis was used to identify the primary site of phosphorylation as serine residue 546; serine 543 was phosphorylated at a low level. A new construct was designed encoding an engineered gelatin, FG-5009, with point mutations that eliminated the charge heterogeneity. FG-5009 was not recognized by antigelatin IgE antibodies from children with confirmed gelatin allergies, establishing the low allergenic potential of this gelatin. The homogeneity of FG-5009, the ability to produce large quantities in a reproducible manner, and its low allergenic potential make this a superior substitute for the animal gelatin hydrolysates currently used to stabilize many pharmaceuticals.

Recombinant collagen and gelatin for drug delivery

The tools of recombinant protein expression are now being used to provide recombinant sources of both collagen and gelatin. The primary focus of this review is to discuss alternatives to bovine collagen for biomedical applications. Several recombinant systems have been developed for production of human sequence collagens. Mammalian and insect cells were initially used, but were thought to be too costly for commercial production. Yeast have been engineered to express high levels of type I homotrimer and heterotrimer and type II and type III collagen. Co-expression of collagen genes and cDNAs encoding the subunits of prolyl hydroxylase has lead to the synthesis of completely hydroxylated, thermostable collagens. Human types I and III collagen homotrimers have been expressed in transgenic tobacco plants, while transgenic mice have been engineered to produce full-length type I procollagen homotrimer as well as a alpha2 (I) homotrimeric mini-collagen. Most recently, a transgenic silkworm system was used to produce a fusion protein containing a collagenous sequence. Each of these transgenic systems holds great promise for the cost-effective large-scale production of recombinant human collagens. As seen in other recombinant expression systems, transgenic silkworms, tobacco, and mice lack sufficient endogenous prolyl hydroxylase activity to produce fully hydroxylated collagen. In mice and tobacco, this was overcome by over-expression of prolyl hydroxylase, analogous to what has been done in yeast and insect cell culture. In addition to recombinant alternatives to bovine collagen, other sources such as fish and sponge collagen are discussed briefly. Recombinant gelatin has been expressed in Pichia pastoris and Hansenula polymorpha in both non-hydroxylated and hydroxylated forms. Pichia was shown to be a highly productive system for gelatin production. The recombinant gelatins produced in yeast are of defined molecular weight and physio-chemical properties and represent a new biomaterial not previously available from animal sources. Genetic engineering has made great progress in the areas of recombinant collagen and gelatin expression, and there are now several alternatives to bovine material that offer an enhanced safety profile, greater reproducibility and quality, and the ability of these materials to be tailored to enhance product performance.

Cycle ergometry is not a sensitive diagnostic test for mitochondrial myopathy

Cycle exercise has repeatedly been used to diagnose patients suspected of having mitochondrial myopathy (MM), in whom exercise intolerance and lactic acidosis are common. No standardized test, however, has been established. We evaluated the diagnostic value of incremental and constant workload (20 min at 65 % VO(2max)) cycle tests for the diagnosis of MM. Plasma lactate and oxidative capacity (VO(2) and workload) were measured in 15 well-characterized MM patients during cycling. Findings were compared with those in 10 myotonic dystrophy patients and 18 sedentary, healthy subjects. All MM patients had ragged red or COX-negative fibers on muscle biopsy. VO(2max) and maximal workload were lower in MM than in control groups (P < 0.02). Resting plasma lactate was higher in MM than in control groups (P < 0.005; sensitivity = 93 %; specificity = 85 %), while exercise-induced increases in plasma lactate were only higher during the constant workload protocol in MM patients vs. control groups (P < 0.05; sensitivity = 27 %; specificity = 86 %). The findings indicate that the diagnostic value of a constant workload protocol is superior to an incremental cycle test, but that the test is less sensitive for MM than simple testing of resting lactate and muscle morphology. Cycle testing of MM patients remains an important research tool, but should not be a standard diagnostic procedure for MM.

The application of quantitative oil streaking to the HeartQuest left ventricular assist device

Methods of flow visualization using oil streaking are established techniques for investigating surface shear and near wall flow patterns. Recent studies have used an array of oil dots on a surface which form streaks when exposed to shear forces. This method is generally qualitative, but it is possible to make quantitative measurements of the shear if the oil streaks have been calibrated. This paper presents the application of a quantitative oil streak method to the HeartQuest left ventricular assist device (LVAD). An array of dots was applied to the top housing of the pump, yielding quantitative values for the shear and qualitative patterns of the near wall flow in that region. The results were used to locate regions likely to promote thrombosis, such as stagnation points or recirculation regions. Regions of high shear, where hemolysis might occur, also can be identified with this method. In addition to being an important design technique, quantitative oil streaking assisted in the verification of computational fluid dynamics results within the HeartQuest LVAD.

No BRCA1 germline mutation in a family with uterine papillary serous carcinoma: a case report

The purpose of the study was to examine BRCA1 germline mutation and its relationship to BRCA1 expression in two patients, a mother and a daughter, both diagnosed with uterine papillary serous carcinoma (UPSC). DNA was screened for BRCA1 and BRCA2 germline mutations common in the Jewish population (185delAG, 5382insC, and 6174delT) by PCR-based assay and with a protein truncation test (PTT) to detect mutation in exon 11 of BRCA1 and exons 10 and 11 of BRCA2. BRCA1 expression in fixed tumor tissues was assessed by immunocytochemistry (IHC). No germline mutation in either BRCAI or BRCA2 gene was found in the two patients. Both samples showed reduced levels of BRCAI expression. Taken together, these results suggest that undetected or unscreened for germline mutation may be associated with occurrence of this rare tumor type in two members of the same family. Alternatively, an epigenetic mechanism such as BRCA1 promoter hypermethylation may be responsible for reduced expression of BRCA1 in the absence of DNA mutations.

Surgical correction of a congenital preputial and penile deformity in a dog

An 11-month-old, intact male Great Pyrenees was presented for recurrent, nonpainful accumulation of suppurative fluid within the prepuce. Surgical exploration revealed a continuation of the urethral mucosa with the cutaneous epidermis of the prepuce, thus creating a closed preputial cavity surrounding the penis where fluid could accumulate. A persistent frenulum and a previously undescribed tissue remnant connecting the dorsal and distal aspects of the penis to the dorsal wall of the prepuce were also present. Surgical correction of the preputial and penile deformity, along with correction of the resulting paraphimosis and pendulous prepuce that became apparent following the initial surgery, are discussed.

Pancreatitis in a cat demonstrating pancreatic duct dilatation ultrasonographically

A 17-year-old, castrated male domestic shorthair cat presented with nonspecific clinical findings of three days' duration. Complete blood counts and serum biochemistry profiles revealed evidence of hepatic dysfunction. Ultrasonographic evaluation revealed abnormalities consistent with pancreatitis, with suspected pancreatic duct dilatation in the left limb of the pancreas. Surgery and eventual necropsy confirmed a diagnosis of pancreatitis, along with pancreatic duct dilatation. Dilatation of the pancreatic duct may be another ultrasonographic change to look for when suspecting feline pancreatitis.

Incidence and significance of pneumomediastinum after laparoscopic esophageal surgery

BACKGROUND

Pneumomediastinum can be a sign of esophageal perforation. During laparoscopic esophageal surgery, the mediastinum is exposed to carbon dioxide gas under pressure that can cause pneumomediastinum.

METHODS

Forty-five patients undergoing laparoscopic esophageal procedures had erect, inspiratory, single-view chest radiographs (CXR) performed in the recovery room (RR). Patients with extraabdominal gas underwent daily erect, inspiratory, single-view CXR until resorption of the gas or discharge from the hospital. Insufflation time and pressure were recorded, and morbidity was evaluated. Results are expressed as mean +/- SEM.

RESULTS

Twenty-five men (56%)and 20 women (44%) aged 33.0 +/- 2.9 years underwent 10 Heller myotomies (22.2%), 27 Nissen fundoplications (60.0%), six Toupet fundoplications (13.3%), and two paraesophageal hernia repairs (4.4%). Twenty-four patients (53.3%) had normal CXR in RR, and 21 (46.7%) had extraabdominal gas. Eighteen (85.7%) of the 21 had pneumomediastinum, three (14.3%) had pneumothorax, and 12 (57.1%) had subcutaneous emphysema in RR. Sixteen of these 21 remained hospitalized and had repeat CXR on postoperative day 1. Of these 16, five (31.3%) had normal CXR, 11 (68.8%) had pneumomediastinum, and seven (43.8%) had subcutaneous emphysema. There were no esophageal perforations and no chest tube insertions, and there was no morbidity related to pneumomediastinum.

CONCLUSION

Pneumomediastinum is observed frequently following laparoscopic esophageal operations and often persists past 24 h. After these operations, pneumomediastinum is not necessarily indicative of esophageal perforation. In this group, it caused no clinically significant events that altered the course of the patients.

Primary hemangiosarcoma of the iliopsoas muscle eliciting a peripheral neuropathy

An eight-year-old, male castrated bullmastiff presented to the Kansas State University Veterinary Medical Teaching Hospital with left hind-limb paralysis. A mass was identified in the left paralumbar soft tissue adjacent to the fourth (L4) to sixth (L6) lumbar vertebrae by magnetic resonance imaging. The iliopsoas muscle contained the mass which was identified as a hemangiosarcoma on histopathological examination. Hemangiosarcoma is rarely reported as a primary tumor arising from muscle vascular endothelium.

Surgical wound morbidity in an austere surgical environment

Surgical wound morbidity was analyzed for a U.S. military field hospital deployed to the Republic of Haiti in support of Operation New Horizons 1998. The purpose of the analysis was to determine if procedures performed in the field hospital had greater infectious risks as a result of the environment compared with historical reports for traditional hospital or clinic settings. Acceptable historical infection rates of 1.5% for clean surgical cases, 7.7% for clean contaminated cases, 15.2% for contaminated cases, and 40% for dirty cases have been noted. There were 827 operations performed during a 6-month period, with the majority of patients assigned American Society of Anesthesiologists Physical Status Classification class I or II. The distribution of these cases was: 72% clean cases, 5% clean contaminated cases, 4% contaminated cases, and 19% dirty cases. The overall wound complication rate was 3.6%, which included 5 wound infections, 11 wound hematomas, 8 superficial wound separations, and 6 seromas. The infectious morbidity for clean cases, the index for evaluation of infectious complications, was 0.8%, well within the accepted standards. There were two major complications that required a return to the operating room: a wound dehiscence with infection in an orchiectomy, and a postoperative hematoma with airway compromise in a subtotal thyroidectomy. There were no surgical mortalities. The infectious wound morbidity for operations performed in the field hospital environment was found to be equivalent to that described for the fixed hospital or clinic settings. No special precautions were necessary to ensure a low infection rate. The safety for patients undergoing elective surgical procedures has been established. Further training using these types of facilities should not be limited based on concerns for surgical wound morbidity.