Patterns of amino acid enzyme in domestic fowl breast and leg muscle during development

Activities of alanine and aspartate transaminases, glutamine synthetase, adenylate deaminase, glutamate and xanthine dehydrogenases and lactate dehydrogenase were measured in leg and breast muscles of developing chicks from day 10 in ovo to day 5 of free life, and compared with measurements for adult hens. Xanthine dehydrogenase activity was low in both muscles with adult levels attained on day 15 in ovo. Glutamine synthetase for chicks was maintained higher during development than for adults in both muscles. Minor differences were observed between both muscles in all enzymes tested up to day 18. With low embryonic values and important rises before hatching, the differences were initiated in the posthatching period. Important differences were observed between adult levels of activity. Leg muscle revealed higher enzyme values except for lactate dehydrogenase and indistinguishable levels for adenylate deaminase and xanthine dehydrogenase in both muscles. Alanine, instead of glutamine, is postulated as the main nitrogen transport between muscle and liver in the domestic fowl.     

Blood flow in skeletal muscles of chicken in the embryonic and early postembryonic periods

In chicken Leghorn, blood flow volume speed in pectoralis and gastrocnemius muscles was measured on 15 and 19 day-old embryos and at the 1st and the 10th days alter hatching. It was revealed that in the last quarter of embryogenesis BF in muscles did not vary remaining in both muscles in identical limits. Similar BF parameters in pectoralis and gastrocnemius muscles and their age-dependent dynamics were observed at embryos with the detained development (with the body weight 2-fold less than the norm). After hatching, the blood flow in both muscles was grown, on the average, 2.4-fold and remained high by the 10th day, a little decreasing in the pectoralis muscle. It was shown, that increase of a muscular blood flow after hatching was accompanied by different changes of anatomic lumen of the arteries addressed in pectoralis and gastrocnemius muscles: in the former it decreased, in the latter--increased.     

The primary structure of chicken muscle acylphosphatase isozyme Ch2

The amino acid sequence of one, Ch2, of the two isozymes of chicken muscle acylphosphatase was determined. It consists of 98 amino acid residues with N-acetylalanine at the amino(N)-terminus and contains no cysteine: Ac-Ala-Gly-Ser-Glu- Gly-Leu-Met-Ser-Val-Asp-Tyr-Glu-Val-Ser-Gly-Arg-Val-Gln-Gly-Val-Phe-Phe- Arg- Lys-Tyr-Thr-Gln-Ser-Glu-Ala-Lys-Arg-Leu-Gly-Leu-Val-Gly-Trp-Val-Arg-Asn- Thr- Ser-His-Gly-Thr-Val-Gln-Gly-Gln-Ala-Gln-Gly-Pro-Ala-Ala-Arg-Val-Arg-Glu- Leu- Gln-Glu-Trp-Leu-Arg-Lys-Ile-Gly-Ser-Pro-Gln-Ser-Arg-Ile-Ser-Arg-Ala-Glu- Phe- Thr-Asn-Glu-Lys-Glu-Ile-Ala-Ala-Leu-Glu-His-Thr-Asp-Phe-Gln-Ile-Arg-Lys- COOH. The sequence differs in 44% of the total positions from the other isozyme, Ch1. Comparison of the sequence and the predicted conformational profile of Ch2 with those of Ch1 suggests that they share a common evolutionary origin and appear to have retained similar conformations throughout their evolutionary development.     

Die Beinmuskulatur und ihre Innervation bei der VogelspinneDugesiella hentzi (Ch.) (Araneae,Aviculariidae)

Zusammenfassung Gestützt auf präparative Untersuchungen und histologische Serienschnitte werden Zahl, Lage, Funktion und nervöse Versorgung aller Muskeln in den Laufbeinen der erwachsenen VogelspinneDugesiella hentzi (Ch.) beschrieben. In den acht Laufbeinen können gleichermaßen jeweils dreißig Muskeln unterschieden werden.Bis auf eine Ausnahme (M. 30) erfolgt die Innervation sämtlicher Beinmuskeln durch den Beinnerv B, wobei die Versorgung durch mehrere (bis zu 6) Nervenäste pro Muskel die Regel ist. Jeder Ast aus Nerv B enthält eine große Anzahl von Axonen. Die aus Ansatz und Ursprung ersichtliche gemeinsame Funktion verschiedener Beinmuskeln spiegelt sich auch in der Innervation aus gemeinsamen Seitenästen von Nerv B wieder.Soweit möglich werden die vermutlich homologen Beinmuskeln aus Untersuchungen anderer Autoren an anderen Arten gegenübergestellt.

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Anatomy of the leg muscles and their innervation in the tarantulaDugesiella hentzi (Ch.) (Araneae, Aviculariidae)

Summary All muscles in the walking legs of the adult tarantulaDugesiella hentzi (Ch.) are described according to their position, function, and innervation pattern. Each leg contains 30 muscles. With the exception of one (M. 30) all of them receive their motor innervation through multiple branches from the main motor nerve B. Muscle 30 is innervated through the mixed nerve A. Each branch leaving nerve B contains a large number of axons.Similarities in the function of different muscles as derived from their attachment at particular leg joints are reflected in the innervation pattern by common branches of nerve B.The leg muscles fromDugesiella are homologized with those of six other species of spiders from different families.

     

C4B3 allotype with a novel Ch phenotype

The fourth component of complement (C4) has two classes of protein, C4A and C4B, both of which have many allelic forms. The serological determinants Rodgers (Rg1, Rg2) and Chido (Ch1, Ch2, Ch3) are generally associated with C4A and C4B, respectively. The C4B3 allotype has been detected in a single Canadian family that expresses a novel Ch phenotype, Ch:–1, 2, –3. There was no information for the Rg determinants, as the C4A ^* 2B ^* 3 haplotype would normally express Rg on the C4A protein. Other C4B3 allotypes in informative families have different Ch phenotypes, and the relationships of these within extended major histocompatibility complex haplotypes are discussed in this paper.     

Production of high levels of 8:0 and 10:0 fatty acids in transgenic canola by overexpression of Ch FatB2, a thioesterase cDNA from Cuphea hookeriana

The Mexican shrub Cuphea hookeriana accumulates up to 75% caprylate (8:0) and caprate (10:0) in its seed oil. An acyl-ACP thioesterase cDNA from C. hookeriana , designated Ch FatB2 , has been identified, which, when expressed in Escherichia coli , provides thioesterase activity specific for 8:0- and 10:0-ACP substrates. Expression of this clone in seeds of transgenic canola, an oilseed crop that normally does not accumulate any 8:0 and 10:0, resulted in a dramatic increase in the levels of these two fatty acids accompanied by a preferential decrease in the levels of linoleate (18:2) and linolenate (18:3). The Ch FatB2 differs from Ch FatB1 , another Cuphea hookeriana thioesterase reported recently, in both substrate specificity and expression pattern. The Ch FatB1 has a broad substrate specificity with strong preference for 16:0-ACP and is expressed throughout the plant; whereas Ch FatB2 is specific for 8:0/10:0-ACP and its expression is confined to the seed. It is proposed that the amplified expression of Ch FatB2 in the embryo provides the hydrolytic enzyme specificity determining the fatty acyl composition of Cuphea hookeriana seed oil.     

The primary structure of chicken muscle acylphosphatase isozyme Ch1

The amino acid sequence of chicken muscle acylphosphatase isozyme Ch1 was determined. The protein consists of 102 amino acid residues, does not contain histidine, and the NH2-terminus is acetylated: Ac-Ser-Ala-Leu-Thr-Lys-Ala-Ser-Gly-Ser- Leu-Lys-Ser-Val-Asp-Tyr-Glu-Val-Phe-Gly-Arg-Val-Gln-Gly-Val-Cys-Phe-Arg- Met- Tyr-Thr-Glu-Glu-Glu-Ala-Arg-Lys-Leu-Gly-Val-Val-Gly-Trp-Val-Lys-Asn- Thr- Ser-Gln-Gly-Thr-Val-Thr-Gly-Gln-Val-Gln-Gly-Pro-Glu-Asp-Lys-Val-Asn-Ala- Met- Lys-Ser-Trp-Leu-Ser-Lys-Val-Gly-Ser-Pro-Ser-Ser-Arg-Ile-Asp-Arg-Thr-Lys- Phe-Ser- Asn-Glu-Lys-Glu-Ile-Ser-Lys-Leu-Asp-Phe-Ser-Gly-Phe-Ser-Thr-Arg-Tyr-OH. This sequence differs in 44% of the total positions from the other isozyme (Ch2) of chicken muscle acylphosphatase (Ohba et al., the accompanying paper). The sequence of Ch1 has three substitutions from that of turkey muscle acylphosphatase; these are Ser from Ala at position 9, Ser from Arg at 47, and Lys from Asn at 83. The sequence has about 80% homology with those mammalian muscle acylphosphatases.     

Characterization of Natronobacterium magadii phage ΦCh1, a unique archaeal phage containing DNA and RNA

A novel archaeal bacteriophage, ΦCh1, was isolated from a haloalkalophilic archaeon Natronobacterium magadii upon spontaneous lysis. The phage-cured strain N. magadii (L13) was used to demonstrate infectivity of phage ΦCh1. The turbid-plaque morphology and the fact that N. magadii cells isolated from plaques were able to produce phage indicated that ΦCh1 is a temperate phage. The phage morphology resembles other members of Myoviridae -infecting Halobacterium species. In solution below 2 M NaCl, the phage lost its morphological stability and infectivity. One- and two-dimensional SDS–PAGE of phage particles revealed at least four major and five minor proteins with molecular masses ranging from 15 to 80 kDa and acidic isoelectric points. Southern blot analysis of chromosomal DNA of a lysogenic N. magadii strain showed that ΦCh1 exists as a chromosomally integrated prophage. The phage particles contain both double-stranded, linear DNA (approx. 55 kbp) as well as several RNA species (80–700 nucleotides). Hybridization of labelled RNA fragments to total DNA from N. magadii and ΦCh1 showed that the virion-associated RNA is host encoded. Part of the phage DNA population is modified and restriction analysis revealed evidence for adenine methylation. Phage ΦCh1 is the first virus described for the genus Natronobacterium , and the first phage containing DNA and RNA in mature phage particles.     

Synthesis and secretion of Ch 21 protein in embryonic chick skeletal tissues

We reported the identification, purification and characterization of a low molecular weight protein (Ch 21) expressed in vitro by differentiating chondrocytes at a late stage of development and observed in vivo in the growth plate region of the long bones at the border between hypertrophic cartilage and newly formed bone (Descalzi Cancedda, F., P. Manduca, C. Tacchetti, P. Fossa, R. Quarto, R. Cancedda, J. Cell Biol. 107, 2455-2463 (1988]. In this article, the synthesis and location of Ch 21 protein in the chick embryo tibia at late stage of development were further investigated. Ch 21 was observed in the cartilage matrix surrounding marrow cavities and in the prearticular outer layer by immunolocalization. In addition, the timing of Ch 21 appearance during the tibia development and its distribution in the growth plate region was better defined. We first observed presence of Ch 21 in the perichondral mid-diaphyseal sleeve of 7-day-old tibia. Ch 21 antibodies stained also the newly formed bone. Synthesis and secretion in the culture medium of Ch 21 protein was observed when bone fragments or cultured osteoblasts isolated from 19-day-old embryo tibiae were labeled in vitro. A search for the presence of Ch 21 in the chick embryo sternum was performed. The synthesis of Ch 21, both in the presumptive calcification cranial portion and in the permanent cartilaginous caudal portion of the sternum, was shown by metabolic labeling of tissue slices.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of probiotic Bacillus subtilis Ch9 for grass carp,Ctenopharyngodon idella (Valenciennes, 1844), on growth performance,digestive enzyme activities and intestinal microflora

In the present study, Bacillus subtilis Ch9 was evaluated as a probiotic in grass carp, Ctenopharyngodon idella (Valenciennes, 1844). For 56 days the grass carp (50 ± 2.5 g) were given a feed containing B. subtilis Ch9 in three concentrations: 1.0 × 10⁹ (T₁), 3.0 × 10⁹ (T₂) and 5.0 × 10⁹ (T₃) CFU kg^?1 feed in triplicate treatments. The control group (T₀) was given feed without B. subtilis Ch9 for the same period. Determined were the specific growth rate (SGR), feed conversion ratio (FCR), and digestive enzyme activities in the intestine and hepatopancreas as well as the intestinal microflora. After 56 days, fish receiving the diets supplemented with B. subtilis Ch9 showed significantly higher SGR and lower FCR (P < 0.05) than those fed the control diet. There was no significant different in SGR and FCR among T₁, T₂ and T₃ nor was the survival rate affected (P > 0.05) by the dietary treatments. From days 14 to 56 of the experiment, higher protease, amylase and lipase activities in the foregut, midgut hindgut and hepatopancreas were observed in T₁, T₂ and T₃ (P < 0.05) compared with the control over a short‐term (14–28 days). Enzyme activity did not increase after long‐term feeding with B. subtilis Ch9 (56 days), but was still higher than that of control fish (P < 0.05). Fish fed the probiotic had an increase in trend of total aerobic and facultative anaerobic bacterial quantity (P > 0.05), but the ratio of Bacillus was significantly higher (P < 0.05) than in control fish. The total anaerobic bacterial quantity, Bifidobacterium and Lactobacillus were significantly higher (P < 0.05) in fish fed B. subtilis Ch9 compared with fish fed control feed. In conclusion, an optimum dose of B. subtilis Ch9 could modulate intestinal microflora, induce digestive enzyme activity and potentially promote the digestion and absorption of nutrients, as well as improve the growth performance of grass carp significantly.     

High beta-hydroxybutyrate concentration in liver and skeletal muscle of newly hatched chicks

Characteristic changes in ketone body concentrations in blood, liver, and skeletal muscle were investigated in detail in newly hatched chicks. The concentration of beta-hydroxybutyrate in the blood was maximal at hatch (0 day), markedly decreased to 3 days, then maintained at low levels, up to 14 days of age. The concentration of acetoacetate in blood, on the other hand, did not change after hatching but remained lower than that of beta-hydroxybutyrate at all ages. In liver and muscles, the concentration of beta-hydroxybutyrate changed in a manner similar to that in the blood. The muscle to blood ratio of the beta-hydroxybutyrate concentration on days -1 and 0 was significantly higher than those at 1 through 14 days post-hatch. These results show that newly hatched chicks have the same high ketone body concentrations in the skeletal muscle, blood and liver. It is, hence, suggested that uptake of beta-hydroxybutyrate by muscles is substantial or that ketogenesis, if any, occurs in muscles immediately before and after hatching of chicks.     

Developmental changes in vitamin A level and lack of retinyl palmitate in chick lungs

1. Developmental changes in retinol and retinyl palmitate contents in lungs of chick embryos and posthatch chicks were investigated. 2. Remarkable changes in the lung retinol levels were found during development of chicks. Embryonic lungs 5 days prior to hatching contained the highest content of retinol. The level then declined rapidly and was lowest on 1 day before hatching. 3. Its level then rose substantially within 7 days after hatching. 4. No retinyl palmitate in chick lungs was detectable at any of the developmental stages examined, nor even in adult hen. 5. Serum retinol level changed in parallel with the lung retinol. 6. The patterns of changes in liver retinol and retinyl palmitate were remarkably different from that occurring in the lung retinol. In chick embryonic livers, the levels of them were low, followed by a rapid increase after hatching. 7. The high level and its rapid decrease of lung retinol content during development of chick embryos may be functionally connected with retinol action in embryonic lungs for cellular differentiation and maturation.     

Isolation mechanisms in closely related grasshopper species <Emphasis Type="Italic">Chorthippus albomarginatus</Emphasis> and <Emphasis Type="Italic">Ch. oschei</Emphasis> (Orthoptera: Acrididae)

Two closely related grasshopper species Chorthippus albomarginatus and Ch. oschei are known to hybridize in the narrow contact zone at the territory of Ukraine and Moldova. Different isolaton mechanisms providing reproductive isolation between the two species were studied. In choice mating experiments, females of the both species demonstrated a strong assortative mating (80–90% preference for the conspecific males). Comparison of the parental and hybrid viability revealed a reduced hatching and increased larval mortality in F₁ and F₂ hybrids. In choice mating experiments, the hybrid females mated less assortatively than the parental females. An assymmetry was found in mating preferences and in viability of hybrids. The results demonstrate the existence of pre-and post-mating isolation between Ch. albomarginatus and Ch. oschei. A possible fate of the hybrid zone is discussed.     

New Necrotic Isolates of Pepino mosaic virus Representing the Ch2 Genotype

New necrotic isolates of Pepino mosaic virus (PepMV) were found in 2007 infecting greenhouse tomato plants in Poland. The isolates differ from previously identified PepMV isolates in host range and symptomatology. They induce severe necrosis on tomato plants ( Solanum lycopersicum ) and local necrotic lesions on Datura inoxia . Phylogenetic analysis, based on three distinct regions, triple gene block 1, the coat protein gene and a part of polymerase gene, revealed that the new necrotic isolates share high nucleotide sequence identity with isolates of the Ch2 genotype. This is the first report describing a necrotic type of PepMV of the Ch2 genotype.     

The Ch21 protein, developmentally regulated in chick embryo, belongs to the superfamily of lipophilic molecule carrier proteins

Ch21, a developmentally regulated low molecular weight protein observed in chick embryo skeletal tissues, is expressed "in vitro" by differentiating chondrocytes at a late stage of development. Here we report the complete amino acid sequence of the protein. 86% of the total amino acid sequence was deduced by sequences of 17 high performance liquid chromatography-separated proteolytic fragments and 33 amino acid residues at the amino-terminal end of protein purified from spent culture medium of hypertrophic chondrocytes. Furthermore we isolated by molecular cloning the corresponding cDNA and determined its nucleotide sequence. By combining protein and nucleotide sequence data we determined the primary structure of the entire Ch21. It consists of 158 amino acids and has a molecular mass of 18.065 kDa. Computer-assisted analysis showed that the Ch21 belongs to the superfamily of low molecular weight proteins sharing a basic framework for binding and transport of small hydrophobic molecules.     

Citrate-cleavage enzyme, `malic'' enzyme and certain dehydrogenases in embryonic and growing chicks

The activities of several enzymes possibly implicated in lipogenesis were measured in the soluble fraction of homogenates of liver and adipose tissue of embryonic and growing chicks. The activities of adipose-tissue enzymes showed little or no change. The activities of hepatic hexose monophosphate-shunt dehydrogenases, malate dehydrogenase, 3-phosphoglyceraldehyde dehydrogenase and NAD-linked α-glycerophosphate dehydrogenase also showed little or no change. Isocitrate dehydrogenase activity in liver rose to a peak on the day of hatching and fell to half the peak value during the next 12 days, where it remained to 26 days after hatching. The activities of `malic' enzyme and citrate-cleavage enzyme showed very low stable values in embryonic liver and remarkable rises during the early part of the post-hatching period. An 85-fold increase in the activity of `malic' enzyme activity was completed in 7 days and a 15-fold increase in that of citrate-cleavage enzyme in 5 days. The activities then attained were maintained up to 26 days after hatching. 2. The increases in the activities of hepatic citrate-cleavage enzyme and `malic' enzyme occurred simultaneously with a marked increase in lipogenesis, suggesting a relationship of these enzymes to lipogenesis in chick liver. By contrast, activity of the hexose monophosphate-shunt dehydrogenases does not appear to be thus associated.     

Proteinase activity in Ascaris suum eggs, hatching fluid, and excretions-secretions.

Hatching fluid and the excretions and secretions (E.S.) of hatched larvae of Ascaris suum revealed proteinase activity when assayed by 2 different procedures employing collagen or casein as substrates. Both assays apparently detected similar levels of proteinase activity in hatching fluid and E.S. of hatched larvae. The Anson (casein substrate) assay worked best in 0.05 M phosphate buffer, pH 8.0. The Azocoll (collagen substrate) assay worked best in 0.05 M borate buffer at pH 8.8. Azocoll assays done at temperatures ranging from 25 to 65 C revealed maximal proteinase activity at 55 C. Analysis of hatching fluid from 18-, 21-, and 28-day-old embryos and of extracts from sonicated 0- to 28-day-old developmental stages showed that proteinase activity increased markedly 18 days after embryonation had begun. Prior to the 18th day of embryonation proteinase levels were relatively low.     

Glycogen metabolic enzymes in the skeletal muscles of the developing chick embryo

In the skeletal muscles of the chick embryo from the 10th till the 15th day of embryogenesis, phosphorylase (EC. 2.4.1.1) is represented by two isozymes one of which corresponds, by electrophoretic mobility, to the liver phosphorylase and another to phosphorylase of the skeletal muscles of the adult rat. From the 17th day of embryogenesis on only one isozyme of phosphorylase is found in the skeletal muscles which is identical with that of the skeletal muscles of the adult bird. The isozyme spectrum of phosphorylase of the whole 4 days old embryo contains, besides phosphorylase L, a special "embryonic" isozyme which differs from that of the skeletal muscles by immunochemical characteristics and electrophoretic mobility. From the 10th day of embryogenesis till hatching, the activity of phosphorylase of the skeletal muscles increases more than 50 times and that of glycogen synthetase (EC. 2.4.1.11) only 4 times.     

DEVELOPMENTAL CHANGES IN LEVELS AND FORMS OF CHOLINESTERASES IN MUSCLES OF NORMAL AND DYSTROPHIC CHICKENS

Abstract— Acetylcholinesterase (AChE) and pseudocholinesterase (°ChE) were studied in vivo and during the first several months of development of pectoral and posterior latissimi dorsi (PLD) muscles in normal and dystrophic chickens. Muscle extracts were prepared in a high ionic strength-nonionic detergent medium in the presence of protease inhibitors, in order to obtain complete solubilization and to prevent degradation of intrinsic molecular forms of both enzymes. In both normal and dystrophic pectoral muscles levels of AChE and °ChE increase rapidly in vivo, °ChE accounting for 5–10% of total cholinesterase activity. In the normal pectoral muscle the concentration of both enzymes drops rapidly after hatching with increasing muscle mass; total AChE per muscle remains relatively constant for 30 days post-hatch. In the dystrophic pectoral muscle both AChE and °ChE accumulate after hatching, resulting in greatly elevated levels (approx 10–25-fold) of both enzymes throughout the period studied. Multiple molecular forms of AChE and °ChE are observed in the pectoral muscle by sucrose gradient centrifugation. Four principal forms are distinguished: two light (L₁, L₂), one medium (M), and one heavy (H₂). The °ChE forms are 0.5–1.0 S units lighter than the corresponding AChE forms. L₂ is the predominant light form of AChE, whereas L₁ is the major light °ChE form detected. The lighter forms of AChE predominate in normal and dystrophic embryonic pectoral muscle at day 14, being replaced by the H₂ form by day 19. H₂ is the major °ChE form detected at day 19. After hatching, H₂ AChE is the predominant form found in both of the normal muscles studied. In the dystrophic pectoral muscle, progressive accumulation of the L₂ form of AChE is detected as early as day 4 post-hatch; this form eventually becomes predominant, although the heavier forms are also elevated. In PLD muscle the same phenomenon occurs, but with a slower time course. In dystrophic pectoral muscle a similar rise in the L₁ form of °ChE is first observed by day 4, with heavier forms also elevated in the mature muscle. Thus the alteration in the control of these two enzymes in dystrophic fast-twitch muscles results in an accumulation of the light forms of AChE and °ChE.     

Ch14.18 antibody produced in CHO cells in relapsed or refractory Stage 4 neuroblastoma patients

Purpose: This study aimed to assess the safety, pharmacokinetic and activity profiles of the human-mouse chimeric monoclonal anti-disialoganglioside GD2 antibody ch14.18 produced in Chinese hamster ovary (CHO) cells (ch14.18/CHO).

Methods: Sixteen children with recurrent/refractory neuroblastoma (median age 7.6 y) were enrolled in this Phase 1 dose-finding study. Patients received ch14.18/CHO courses of 10, 20 or 30 mg/m²/day as an eight-hour infusion over five consecutive days. Three courses at the same dose level were allowed unless disease progressed. Clearance and biodistribution of radiolabelled ch14.18/CHO in Balb/c and A/J mice were analyzed.

Results: A total of 41 ch14.18/CHO courses were given (10 × 3 courses, 5 × 2 courses, 1 × 1 course). Side effects were similar in expectedness, frequency and magnitude to those reported for ch14.18/SP2/0. The dose level of 20 mg/m²/day was confirmed. Toxicity was reversible and no treatment-related deaths occurred. In children, the peak plasma concentration was 16.51 µg/ml ± 5.9 µg/ml and the half-life was 76.91 h ± 52.5 h. A partial response following ch14.18/CHO was observed in 2/7 patients with residual disease. In mice, the half-lives were 22.7 h ± 1.9h for ch14.18/CHO and 25.0 h ± 1.9 h for ch14.18/SP2/0. The biodistribution of ¹²⁵I-ch14.18/CHO in mice with neuroblastoma was identical to ¹²⁵I-ch14.18/SP2/0, indicating GD₂ targeting activity in vivo.

Ch14.18 produced in CHO cells showed an unchanged toxicity profile and pharmacokinetics in neuroblastoma patients compared with ch14.18 produced in SP2/0 cells, and evidence of clinical activity was observed. In mice, analysis of pharmacokinetics and biodistribution showed comparable results between ch14.18/CHO and ch14.18/SP2/0. Based on these results, ch14.18/CHO was accepted for prospective clinical evaluation.