Spontaneous immortalization of chicken fibroblasts generates stable, high-yield cell lines for serum-free production of cultured meat

Cellular agriculture could meet growing demand for animal products, but yields are typically low and regulatory bodies restrict genetic modification for cultured meat production. Here we demonstrate the spontaneous immortalization and genetic stability of fibroblasts derived from several chicken breeds. Cell lines were adapted to grow as single-cell suspensions using serum-free culture medium, reaching densities of 108 × 10⁶ cells per ml in continuous culture, corresponding to yields of 36% w/v. We show that lecithin activates peroxisome proliferator-activated receptor gamma (PPARγ), inducing adipogenesis in immortalized fibroblasts. Blending cultured adipocyte-like cells with extruded soy protein, formed chicken strips in which texture was supported by animal and plant proteins while aroma and flavour were driven by cultured animal fat. Visual and sensory analysis graded the product 4.5/5.0, with 85% of participants extremely likely to replace their food choice with this cultured meat product. Immortalization without genetic modification and high-yield manufacturing are critical for the market realization of cultured meat.

Near-field electromagnetic theory for thin solar cells

Current methods for evaluating solar cell efficiencies cannot be applied to low-dimensional structures where phenomena from the realm of near-field optics prevail. We present a theoretical approach to analyze solar cell performance by allowing rigorous electromagnetic calculations of the emission rate using the fluctuation-dissipation theorem. Our approach shows the direct quantification of the voltage, current, and efficiency of low-dimensional solar cells. This approach is demonstrated by calculating the voltage and the efficiency of a GaAs slab solar cell for thicknesses from several microns down to a few nanometers. This example highlights the ability of the proposed approach to capture the role of optical near-field effects in solar cell performance.

Differential effects of co-chaperonin homologs on cpn60 oligomers

In this study, we have investigated the relationship between chaperonin/co-chaperonin binding, ATP hydrolysis, and protein refolding in heterologous chaperonin systems from bacteria, chloroplast, and mitochondria. We characterized two types of chloroplast cpn60 oligomers, ch-cpn60 composed of alpha and beta subunits (alpha(7)beta(7) ch-cpn60) and one composed of all beta subunits (beta(14) ch-cpn60). In terms of ATPase activity, the rate of ATP hydrolysis increased with protein concentration up to 60 microM, reflecting a concentration at which the oligomers are stable. At high concentrations of cpn60, all cpn10 homologs inhibited ATPase activity of alpha(7)beta(7) ch-cpn60. In contrast, ATPase of beta(14) ch-cpn60 was inhibited only by mitochondrial cpn10, supporting previous reports showing that beta(14) is functional only with mitochondrial cpn10 and not with other cpn10 homologs. Surprisingly, direct binding assays showed that both ch-cpn60 oligomer types bind to bacterial, mitochondrial, and chloroplast cpn10 homologs with an equal apparent affinity. Moreover, mitochondrial cpn60 binds chloroplast cpn20 with which it is not able to refold denatured proteins. Protein refolding experiments showed that in such instances, the bound protein is released in a conformation that is not able to refold. The presence of glycerol, or subsequent addition of mitochondrial cpn10, allows us to recover enzymatic activity of the substrate protein. Thus, in our systems, the formation of co-chaperonin/chaperonin complexes does not necessarily lead to protein folding. By using heterologous oligomer systems, we are able to separate the functions of binding and refolding in order to better understand the chaperonin mechanism.

Observation of the spin-based plasmonic effect in nanoscale structures

Observation of surface-plasmon phenomena that are dependent upon the handedness of the circularly polarized incident light (spin) is presented. The polarization-dependent near-field intensity distribution obtained in our experiment is attributed to the presence of a geometric phase arising from the interaction of light with an anisotropic and inhomogeneous nanoscale structure. A near-field vortex surface mode with a spin-dependent topological charge was obtained in a plasmonic microcavity. The remarkable phenomenon of polarization-sensitive focusing in a plasmonic structure was also demonstrated.

The vein of Labbe masquerading as an epidural abscess

The occipitotemporal vein (OTV) courses over the temporal lobe, connecting the superficial middle cerebral vein and the transverse sinus. This vein is rarely identifiable on computerized tomography (CT) scans and a large amount of contrast is needed to identify such a relatively small vessel. We present a 12-month-old male with acute coalescent mastoiditis and a subperiosteal abscess. An epidural abscess was suspected on pre-operative CT scan. No abscess was found on surgery. Based on the surgical finding, we determined that this misdiagnosis was due to a vascular variant, the occipitotemporal vein (vein of Labbe) that masqueraded as an abcess on the CT scan. Recognition of the vein of Labbe on CT scan is therefore essential for the appropriate management of otological and neurotological disease.

Significance of the N-terminal domain for the function of chloroplast cpn20 chaperonin

Chaperonins cpn60 and cpn10 are essential proteins involved in cellular protein folding. Plant chloroplasts contain a unique version of the cpn10 co-chaperonin, cpn20, which consists of two homologous cpn10-like domains (N-cpn20 and C-cpn20) that are connected by a short linker region. Although cpn20 seems to function like other single domain cpn10 oligomers, the structure and specific functions of the domains are not understood. We mutated amino acids in the "mobile loop" regions of N-cpn20, C-cpn20 or both: a highly conserved glycine, which was shown to be important for flexibility of the mobile loop, and a leucine residue shown to be involved in binding of co-chaperonin to chaperonin. The mutant proteins were purified and their oligomeric structure validated by gel filtration, native gel electrophoresis, and circular dichroism. Functional assays of protein refolding and inhibition of GroEL ATPase both showed (i) mutation of the conserved glycine reduced the activity of cpn20, whether in N-cpn20 (G32A) or C-cpn20 (G130A). The same mutation in the bacterial cpn10 (GroES G24A) had no effect on activity. (ii) Mutations in the highly conserved leucine of N-cpn20 (L35A) and in the corresponding L27A of GroES resulted in inactive protein. (iii) In contrast, mutant L133A, in which the conserved leucine of C-cpn20 was altered, retained 55% activity. We conclude that the structure of cpn20 is much more sensitive to alterations in the mobile loop than is the structure of GroES. Moreover, only N-cpn20 is necessary for activity of cpn20. However, full and efficient functioning requires both domains.

Candida parotitis with abscess formation

This report describes the case of an elderly, diabetic man who developed acute suppurative parotitis with abscess formation. The causative agent of parotid abscess was Candida albicans, which is an unusual cause of salivary gland pathology. The parotid gland is the salivary gland most commonly affected by inflammation. Acute parotitis occurs most often in elderly patients who are debilitated by systemic disease or are in a state of dehydration following major surgical procedures. Despite the high prevalence of oral candida carriage, there have been few previous reports of candida sialoadenitis in the literature. This is due to the toxicity of saliva to fungi under normal conditions. The diagnosis of candidiasis in our patient was made by culturing the purulent discharge from Stensen's duct and by culture of the pus obtained at surgical drainage of the abscess. After incision and drainage, the patient was treated with intravenous and then oral fluconazole for a total of 4 weeks with complete resolution of his condition. This case is interesting in light of recent and ongoing investigations of salivary proteins as potential new antifungal agents.

Acute mastoiditis in infancy: the Soroka experience: 1990-2000

Acute mastoiditis (AM) is an uncommon but serious complication of acute otitis media (AOM). In the pre-antibiotic era, AM was seen more frequently than it is today, but it was rare in infants. However, in the last two decades an increase in the incidence of AM in infancy has been reported in the literature. During the years 1990-2002, we treated 113 patients with 128 episodes of AM; of them, 24 were infants (median age 6 months; 18 males) who suffered from 26 episodes of AM. Twenty developed AM as a complication of their first episode of AOM. One of the four infants with a prior history of AOM suffered from common variable immunodeficiency. A significant increase in the incidence of AM in infants was recorded during the study period (P = 0.01). The most common presenting clinical signs were post-auricular swelling and fever >38 degrees C (77% and 77%, respectively, of all patients). Seventeen episodes of AM were not treated with prior antibiotics. Tympanocentesis was performed in all episodes of AM. Middle ear fluid culture was positive in 17 (65%) of the 26 AM episodes. The most common pathogens cultured were Streptococcus pneumoniae (10 infants, 58% of all pathogens, 3/10 intermediately susceptible to penicillin) followed by Streptococcus pyogenes (4, 23%), non-typable H. influenzae (2, 12%) and S. aureus (1, 6%). Temporal bone CT showed bone destruction in 14 patients; 3 infants had subperiosteal abscesses and 3 lateral sinus thrombosis. Ten infants underwent mastoid surgery due to non-resolution of symptoms and signs with antibiotic therapy. Eight underwent cortical mastoidectomy with two patients undergoing ventilation tube introduction only. The remainder of the infants healed with conservative treatment.

CONCLUSIONS

(1) A significant increase in the incidence of AM in infants was recorded over the last decade, though a specific reason for this trend remains uncertain; (2) Most of the cases of AM followed the infant's initial AOM episode, and most of the infants had not received prior antibiotic therapy; (3) The clinical signs and symptoms of AM were more severe in infants than in older patients; (4) While S. pneumonia was the most common pathogen isolated in middle ear fluid cultures, the involvement of S. pyogenes in AM was higher than that reported in AOM.

On the oligomeric state of chloroplast chaperonin 10 and chaperonin 20

Type I chaperonins are fundamental protein folding machineries that function in eubacteria, mitochondria and chloroplasts. Eubacteria and mitochondria contain chaperonin systems comprised of homo-oligomeric chaperonin 60 tetradecamers and co-chaperonin 10 heptamers. In contrast, the chloroplast chaperonins are heterooligomeric tetradecamers that are composed of two subunit types, alpha and beta. Additionally, chloroplasts contain two structurally distinct co-chaperonins. One, ch-cpn10, is probably similar to the mitochondrial and bacterial co-chaperonins, and is composed of 10 kDa subunits. The other, termed ch-cpn20 is composed of two cpn10-like domains that are held together by a short linker. While the oligomeric structure of ch-cpn10 remains to be elucidated, it was previously suggested that ch-cpn20 forms tetramers in solution, and that this is the functional oligomer. In the present study, we investigated the properties of purified ch-cpn10 and ch-cpn20. Using bifunctional cross-linking reagents, gel filtration chromatography and analytical ultracentrifugation, we show that ch-cpn10 is a heptamer in solution. In contrast, ch-cpn20 forms multiple oligomers that are in dynamic equilibrium with each other and cover a broad spectrum of molecular weights in a concentration-dependent manner. However, upon association with GroEL, only one type of co-chaperonin-GroEL complex is formed.

Two-step purification of mitochondrial Hsp70, Ssc1p, using Mge1(His)(6) immobilized on Ni-agarose

The most abundant mitochondrial homolog of Hsp70, Ssc1p, is involved in the import and folding of mitochondrial proteins. We have developed an easy and efficient method for purifying Ssc1p. Following a first step of anion exchange at pH 6.6, a column of Mge1(His)(6) immobilized on Ni(2+)-agarose provides an efficient second dimension that results in highly purified protein. The strong and specific interaction between Ssc1p and its cofactor protein, Mge1, ensures that primarily functional protein is isolated. Ssc1p purified by this method hydrolyzed ATP with a turnover rate of 0.3/min. The ATP hydrolysis was enhanced slightly by Mge1, about 5 times by Mdj1, and 12 times by both cofactors together. The CD spectrum of Ssc1p had a pattern and temperature dependence similar to those shown for other hsp70 homologs, with a midpoint of the major transition at approximately 70 degrees C.

Detection of sinus-induced orbital mycosis with standardized orbital ultrasonography: a case report

Fungal involvement of the paranasal sinuses is frequently observed in the immunocompromised host, and it can become life-threatening if it is not diagnosed. Although the definitive diagnosis is made by tissue biopsy and culture, imaging is of vital importance in the clinical workup and in planning treatment. We present a case of fulminant ethmoidal sinusitis caused by Aspergillus flavus with orbital involvement in an immunocompromised patient. Standard computed tomography of the paranasal sinuses was complemented by the use of standardized orbital ultrasonography, which was able to identify the intraorbital extension. We discuss the role of standardized orbital ultrasonography as a complementary imaging modality in the diagnosis of fungal sinusitis and in the assessment of local extension. To the best of our knowledge, the role of SOU in diagnosing an orbital extension of a fungal infection of the paranasal sinuses has not been previously discussed in the literature.

The effect of nucleotides and mitochondrial chaperonin 10 on the structure and chaperone activity of mitochondrial chaperonin 60

Mitochondrial chaperonins are necessary for the folding of newly imported and stress-denatured mitochondrial proteins. The goal of this study was to investigate the structure and function of the mammalian mitochondrial chaperonin system. We present evidence that the 60 kDa chaperonin (mt-cpn60) exists in solution in dynamic equilibrium between monomers, heptameric single rings and double-ringed tetradecamers. In the presence of ATP and the 10 kDa cochaperonin (mt-cpn10), the formation of a double ring is favored. ADP at very high concentrations does not inhibit malate dehydrogenase refolding or ATP hydrolysis by mt-cpn60 in the presence of mt-cpn10. We propose that the cis (mt-cpn60)14.nucleotide.(mt-cpn10)7 complex is not a stable species and does not bind ADP effectively at its trans binding site.

Nasal cavity squamous cell carcinoma in Wegener's granulomatosis

Wegener's granulomatosis is a chronic debilitating disease with multiple organ system involvement, variable course, and myriad complications that cause morbidity and mortality. We report 2 cases of nasal cavity squamous cell carcinoma occurring in long-standing Wegener's granulomatosis.

Identification and typing of human papillomavirus (HPV) in squamous cell carcinoma of the oral cavity and oropharynx

Recent epidemiological research has raised the possibility of a connection between viral infection by the human papilloma virus (HPV) and the existence of squamous cell carcinoma of the oral cavity and oroharynx (SCCa). Some 60 subtypes have been identified to date, and specific subtypes are associated with lesions or infections at specific tissue sites. Twenty-three patients with SCCa of the oral cavity were studied for the presence of HPV in their tumours. HPV DNA (all type 16) was isolated from four specimens (17.3 per cent) using the Polymerase Chain Reaction (PCR) method. The four patients were all over age 50, and had advanced tumours (two T3 and two T4) that originated in the oropharynx. Our data supports other reports in the literature, demonstrating the presence of HPV DNA type 16 within cells from oropharyngeal SCCa. We conclude that the PCR method is a useful and reliable method for the detection of HPV DNA within tumour cells.

Otogenic lateral sinus thrombosis in children

INTRODUCTION

The clinical picture of lateral sinus thrombosis (LST) has changed with the advent of antibiotics, as have the utility of various diagnostic tests. LST may appear in children as a complication of acute otitis media, but nowadays it is more frequently encountered in adults with long-standing chronic ear disease.

METHOD

A retrospective study of all the pediatric patients with LST between 1982 and 1997.

RESULTS

Thirteen cases of LST were diagnosed and treated by our department. In six cases, LST was due to acute otitis media and in the remaining cases it was due to chronic otitis media. Headache, fever, aural discharge and mastoid tenderness were the most frequent findings in these patients and four patients were initially diagnosed with meningitis. In the majority of the patients, LST was accompanied with other intracranial complications, such as perisinus abscess, brain abscess and meningitis. One patient with multiple brain abscesses, unresponsive to several drainage procedures, died. The other patients recovered and have since been followed-up as out-patients.

CONCLUSION

LST may be difficult to diagnose due to previous antibiotic treatment and to the overlap of clinical findings with other entities such as meningitis. Despite the value of modern imaging techniques in the investigation of the disease, a high index of suspicion based on the clinical picture is warranted. Our results are consistent with those of other recent studies, who found that mortality of LST has dropped below 10%.

The use of standardized orbital ultrasound in the diagnosis of sinus induced infections of the orbit in children: a preliminary report

Infections of the orbit in children usually present as a complication of sinusitis and may result in blindness or even death. Orbital cellulitis (OC) and subperiosteal abscess (SPA) represent different pathologies within the spectrum of orbital infections. The differentiation between OC and SPA is important, since it implies two different therapeutic modalities. While SPA is usually treated by incision and drainage and parenteral antibiotics, OC may be treated with antibiotics alone. Contrast enhanced CT scan is commonly used in the diagnosis of orbital infections, but does not always prove accurate in differentiating between these two conditions. MRI is superior to CT in the resolution of soft tissue pathology and may be more precise in such situations, but is less available imaging tool outside North America and Europe. There have been a few reports in the early 1980's on the use of standardized orbital ultrasound (SOU) in these two conditions. We have used SOU in seven children with sinus induced orbital infections--four with SPA and three with OC. We reviewed our experience in these patients and compared the imaging characteristics of OC and SPA on SOU with those of conventional imaging modalities, used in orbital infections. In four of the cases, CT scan was inconclusive, while SUO was diagnostic. In this preliminary report, we conclude that SOU may be useful in the diagnosis of orbital infections.

Outpatient management of acute mastoiditis with periosteitis in children

Children with acute mastoiditis with periosteitis are conventionally hospitalized for parenteral antibiotics and/or surgical treatment. However, if possible, effective and safe outpatient treatment is desirable. During a 36-month period, outpatient parenteral antibiotic therapy (once daily i.m. ceftriaxone) was evaluated in 32 children with acute mastoiditis, with clinical evidence of periosteitis. Inclusion criteria included otomicroscopic evidence of acute otitis media (AOM), displacement of the pinna, retroauricular swelling, erythema and tenderness. The treatment consisted of wide myringotomy and administration of i.m. antibiotics. Daily visits, by a combined team of an otolaryngologist and pediatric infectious disease specialist, were considered essential. Fourteen children (43%) were treated initially in the hospital (and subsequently as outpatients) and 18 (57%) children were treated entirely as outpatients. Mean duration of outpatient treatment was 7 days (range: 4-10). The overall clinical cure rate was 96.8%. One child underwent simple mastoidectomy. No serious side effects were observed. Our data suggests that many children with acute mastoiditis with periosteitis can be managed successfully and safely as outpatients by a combined team of otolaryngologists and infectious disease specialists.

The 3849 + 10 kB C-->T mutation in a 21-year-old patient with cystic fibrosis

Cystic fibrosis (CF) is the most common lethal inherited disease in the white population. It is characterized by exocrine gland epithelia dysfunction, which leads to pulmonary and pancreatic insufficiency. Since the cloning of the CF gene in 1989 and the identification of the most common CF mutation (delta F508), more than 400 different mutations have been described. These mutations appear to contribute to the heterogeneity of the CF phenotype and several reports have speculated on the relationship between the most common CF mutations and the patient's clinical status. We report the case of a 21-year-old woman with longstanding chronic pansinusitis, nasal polyposis, chronic cough and severe nasal crusting. During a period of five years she had been followed by her otolaryngologist and pediatric pulmonologist. Sweat tests performed at the age of 17 and 18 were within normal limits and she underwent repeated conventional sinonasal procedures, with no improvement in her clinical status. On her present admission, sweat tests showed a 70 meq/l chloride concentration. The diagnosis of CF was then confirmed by DNA analysis and the patient was found to carry the 3849 + 10 kB C-->T mutation. The early detection of this newly recognized form of CF in adults as well as in children presenting with sinonasal symptoms is critical for life expectancy and quality.

The 3849+10 kB C—>T Mutation in a 21-Year-Old Patient with Cystic Fibrosis

Cystic fibrosis (CF) is the most common lethal inherited disease in the white population. It is characterized by exocrine gland epithelia dysfunction, which leads to pulmonary and pancreatic insufficiency. Since the cloning of the CF gene in 1989 and the identification of the most common CF mutation (ΔF508), more than 400 different mutations have been described. These mutations appear to contribute to the heterogeneity of the CF phenotype and several reports have speculated on the relationship between the most common CF mutations and the patient's clinical status.

We report the case of a 21-year-old woman with longstanding chronic pansinusitis, nasal polyposis, chronic cough and severe nasal crusting. During a period of five years she had been followed by her otolaryngologist and pediatric pulmonologist. Sweat tests performed at the age of 17 and 18 were within normal limits and she underwent repeated conventional sinonasal procedures, with no improvement in her clinical status. On her present admission, sweat tests showed a 70 meq/l chloride concentration. The diagnosis of CF was then confirmed by DNA analysis and the patient was found to carry the 3849+10 kB C—>T mutation. The early detection of this newly recognized form of CF in adults as well as in children presenting with sinonasal symptoms is critical for life expectancy and quality.

A homogeneous immunofluorescence assay based on dye-sensitized photobleaching

A novel homogeneous immunoassay requiring only one incubation step, and applicable in principle to the determination of low- as well as high-molecular-weight substances, has been developed. The method is based on (a) photooxidation by singlet oxygen (1O2) of a fluorescent substrate (1,3-diphenylisobenzofuran, DPBF) embedded in unilamellar vesicles on the surface of which antibody to the analyte antigen is covalently attached (DPBF-immunoliposomes); (b) generation of singlet oxygen, upon illumination, by a chromophore (erythrosine) covalently attached to an antibody (Ab*) or antigen (Ag*); (c) formation of a "sandwich"- or "competition"-type complex whereupon the singlet oxygen-generating chromophore conjugate (Ab* or Ag*) and immunoliposome-embedded DPBF are brought into close proximity. Competition- and sandwich-type model assay systems for the detection of protein antigens and viruses were investigated. The detection range with protein antigens in competition- and sandwich-type assays was three (10(-10) - 10(-7) M) and two (10(-10) - 10(-8) M) orders of magnitude, respectively. With poliovirus using a sandwich-type assay, the detection range was 10(2) - 10(6) plaque-forming units per milliliter (pfu/ml).

Calcification in an untreated case of Burkitt's lymphoma: radiographic, ultrasound and CT diagnosis

Calcification in untreated lymphoma is exceedingly rare. We report an unusual case of Burkitt's lymphoma, detected on plain radiographs and by ultrasonographic and CT examination.