P30 Group Research Articles

Experimental envenomation with honeybee venom melittin and phospholipase A2 induced multiple ultrastructural changes in adrenocortical mitochondria

Bee stings represent a public health subject, but the mechanisms involved in bee venom toxicity are not yet fully understood. To evaluate the reactions of adrenocortical cells, through which organisms respond to stress, two honeybee venom components: melittin (Mlt) and phospholipase A2 (PLA2) were tested as potential chemical stressors. Modifications were investigated with transmission electron microscopy and microanalysis. A single dose of Mlt (31 mg/kg) or PLA2 (9.3 mg/kg) was injected in rats of groups ML and PL; daily doses of Mlt (350 μg/kg) or PLA2 (105 μg/kg) were injected 30 days in rats of groups M30 and P30. Adrenocortical cells in ML group showed ultrastructural degenerative alterations of nuclei, endoplasmic reticulum, and mitochondria that exhibited lipid inclusions and mitochondrial cristae (MC) re-organized into mono- or multimembrane large vesicles, and whorls of membranes. Many MC were degenerated. In the M30 group, similar ultrastructural changes, but of lower amplitude were noted; lipid cytosolic droplets were heterogenous. MC diameters in Mlt groups (melittin treated groups) were significantly higher than in control (C) group. In PL group, mitochondria contained large lipid inclusions, vesicular MC of different sizes and multiple membranes, and debris, or whorl structures. In P30 group MC were tubular with increased diameters. In both PLA2 groups (PLA2 treated groups) MC were significantly larger than in C group. We concluded that Mlt and PLA2 were powerful stressors, toxic at the tested doses, cellular reactions concerning in all groups mainly mitochondria, but also other cellular compartments. Apart from degenerative regression of MC, the rearrangement of tubular MC occurred into one or multiple large multimembrane vesicular MC. Reactions to the high doses were more pronounced, with the highest amplitude in ML group, and the lowest in P30 group.

Analgesia and stress attenuation of ultrasound-guided modified pectoral nerve block type-II with different volumes of 0.3% ropivacaine in patients undergoing modified radical mastectomy for breast cancer: A prospective parallel randomized double-blind controlled clinical trial.

A previous randomized clinical trial concluded that an optimal concentration of 0.3% ropivacaine could provide satisfactory analgesia for breast cancer patients undergoing modified radical mastectomy. We wondered if a smaller volume (30 ml vs. 40 ml) of 0.3% ropivacaine could still provide adequate analgesia in an ultrasound-guided PECS II block in modified radical mastectomy. We performed a prospective parallel randomized double-blind controlled clinical trial. Eligible patients were assigned to either the P30 or P40 group (30 or 40 ml of 0.3% ropivacaine, respectively). The skin area of hypoesthesia, anaesthetic plane determined with ultrasound, pain visual analogue scale (VAS), anaesthetic dosages, and complications were recorded. Serum levels of interleukin-1β and interleukin-6 were measured postoperatively. A total of 40 patients completed the trials, with 20 patients in each group. Although the skin area of hypoesthesia and the anaesthetic planes were significantly larger in the P40 group compared with the P30 group (p < 0.05), the VAS, analgesic and opioid doses, serum cytokine levels, anaesthetic toxicity, and complications had no significant differences between the two groups. Compared with 40 ml, 30 ml of 0.3% ropivacaine could provide adequate analgesia and reduce surgical stress in patients undergoing modified radical mastectomy for breast cancer.

Human umbilical cord mesenchymal stem cells combined with pirfenidone upregulates the expression of RGS2 in the pulmonary fibrosis in mice

ObjectiveThe therapeutic effect of umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in combination with pirfenidone (PFD) on pulmonary fibrosis in mice and its possible mechanism were investigated.MethodsC57BL/6 mice were randomly divided into six groups: control group, model group, P10 group, P30 group, P100 group, and P300 group. Modeled by tracheal intubation with 3 mg/kg bleomycin drip, each dose of PFD was administered daily by gavage from day 7 onwards. The mice were observed continuously for 21 days and survival was recorded. Lung tissues were collected on day 21, and hematoxylin–eosin (HE) and Masson staining were performed to assess morphological changes and collagen deposition in the lungs. Collagen content was measured by the Sircol method, and fibrosis marker levels were detected by PCR and Western blot. Another batch of C57BL/6 mice was then randomly divided into five groups: hUC-MSC control group, model group, P100 group, hUC-MSC treatment group, and hUC-MSCs + P30 group. On day 7, 5 × 105 hUC-MSCs were injected into the tail vein, the mice were administered PFD gavage daily from day 7 onwards, and their survival was recorded. Lung tissues were collected on day 21 to detect pathological changes, the collagen content, and the expression of regulator of G protein signaling 2 (RGS2). Pulmonary myofibroblasts (MFBs) were divided into an MFB group and an MFB + hUC-MSCs group; different doses of PFD were administered to each group, and the levels of RGS2, intracellular Ca2+, and fibrosis markers were recorded for each group.ResultsCompared with other PFD group doses, the P100 group had significantly improved mouse survival and lung pathology and significantly reduced collagen and fibrosis marker levels (p < 0.05). The hUC-MSCs + P30 group had significantly improved mouse survival and lung pathology, significantly reduced collagen content and fibrosis marker levels (p < 0.05), and the efficacy was better than that of the P100 and hUC-MSCs groups (p < 0.05). RGS2 expression was significantly higher in the MSCs + P30 group compared with the P100 and hUC-MSCs groups (p < 0.05). PFD increased RGS2 expression in MFBs (p < 0.05) in a dose-dependent manner. Compared with PFD and hUC-MSCs treatment alone, combination of hUC-MSCs and PFD increased RGS2 protein levels, significantly decreased intracellular Ca2+ concentration, and significantly reduced fibrosis markers.ConclusionThe findings suggest that hUC-MSCs combined with low-dose PFD have a therapeutic effect better than that of the two treatments used separately. Its effect on attenuating bleomycin-induced pulmonary fibrosis in mice is related to the increase of RGS2.

Screening and identification of microRNAs from plasma-derived extracellular vesicles (EVs) of Dazu black goat (Capra hircus) in early pregnant stages

Previous studies have shown that extracellular vesicles (EVs) containing proteins, lipids, nucleic acids and other biological components exist in all kinds of body fluids. EVs, as an intercellular communication carrier, regulate the functions of its target cells by transporting biomacromolecules between cells. In this study, a total of six female Dazu black goats were divided into NP group (NP, non-pregnant group) and P30 (P30, 30-day pregnant group). The goats in NP group (n=3) were in estrus, but failed to fertilize; the other goats in P30 group (n=3) were fertilized by natural mating. Firstly, goats plasma-derived EVs were isolated using ultracentrifugation. Secondly, EVs were identified by transmission electron microscope (TEM), dynamic light scattering (DLS), and by testing its markers (CD9 and CD63) using west blotting in NP and P30 groups, respectively. Thirdly, EVs related miRNAs were sequenced and analyzed by bioinformatics method. Data shows that miR-31-5p, miR-137-3p, novel_miR_1355, novel_miR_734 and novel_miR_736 exclusively were expressed in P30 group. Their target genes were significantly enriched in the axon guidance, the Notch signaling pathway, the Wnt signaling pathway, tight junction and the Hippo signaling pathway. And miRNA-mRNA interactive network analysis reveals potential regulatory functions of miRNAs for goat during early pregnancy. These findings provided theretical references for studying the regulation of plasma-derived EVs between the fetal and placental development, and these candidate miRNAs identified might be as markers for diagnosis of goat early pregnancy.

Effects of Atorvastatin Calcium on the Survival of Ultra-long Dorsal Random Skin Flaps in Rats

To investigate the effects of atorvastatin calcium (ATR) on the survival of ultra-long dorsal random skin flaps in rats. Thirty SD rats were divided into five groups ( n=6) according to the random number table: normal saline control group (CON group), ATR 10 mg/kg group (P10 group), ATR 20 mg/kg group (P20 group), ATR 30 mg/kg group (P30 group), and ATR 40 mg/kg group (P40 group). After pretreatment with ATR or 0.9% saline for 3 days, an ultra-long dorsal random skin flaps with size of 8 cm×2 cm was made on the back of each rat and replanted in situ. After the operation, the ATR or saline treatment lasted for 3 d. Seven days after operation, the appearance of skin flaps was observed with naked eyes, the survival rate of skin flaps was calculated. The pathological changes in the surviving areas of skin flaps were observed by HE staining, the number of microvessels in skin flaps was observed by immunohistochemistry staining, the mRNA expressions of vascular endothelial growth factor ( VEGF) and basic fibroblast growth factor ( bFGF) were tested by quantitative real-time PCR, and the contents of superoxide dismutase, nitrogen monoxide and malonaldehyde were tested by enzyme linked immunosorbent assays (ELISA). On the 7 thday after operation, the skin flap of the CON group showed a large area of necrosis, and the necrotic part formed crusts. Crusts were hard and inelastic, and a large amount of tissue fluid exudated. The fascial layer showed dark purple. No exudation of tissue fluid was observed in the flaps of P10, P20, P30 and P40 groups. The scab shell fell off naturally and the fur grew normally. HE staining of CON group showed that a large number of inflammatory cell infiltration, epidermal loss and necrosis in skin flaps, but the pathological changes in skin flaps were significantly improved after treatment with ATR. Compared with the CON group, the survival rate of skin flaps, the number of microvessels in skin flaps and the levels of VEGF mRNA, bFGF mRNA, SOD, NO in skin flaps also increased with the dose of ATR, which reached a peak at 30 mg/kg ATR ( P<0.05). However, the level of MDA in skin flaps decreased with the dose of ATR, which reached the lowest at 30 mg/kg ATR ( P<0.05). ATR can enhance the survival of ultra-long dorsal random skin flaps in rats, which may be related to promoting microangiogenesis and inhibiting inflammatory and oxidative stress.

Efficient Production of Live Offspring from Mouse Oocytes Vitrified with a Novel Cryoprotective Agent, Carboxylated ε-poly-L-lysine

In cryopreservation of mammalian germ cells, unfertilized oocytes are one of the most available stages because these cryopreserved oocytes can be used for assisted reproductive technologies, including in vitro fertilization (IVF) and intracytoplasmic sperm injection. However, it has been generally reported that the fertility and developmental ability of the oocytes are reduced by cryopreservation. Therefore further improvement will be required. Very recently, a new cryoprotective agent (CPA), called as carboxylated ε-poly-L-lysine (COOH-PLL), has been developed to reduce physical and physiological damage by cryopreservation in mammalian stem cells. However, it is unclear the effect of COOH-PLL on fertility and developmental ability of vitrified oocytes. In this study, we used COOH-PLL as a CPA with ethylene glycol (EG) for vitrification of mouse oocytes. Cumulus-oocyte complexes (COCs) were collected from ICR mice and then vitrified with Cryotop using different concentration of COOH-PLL and EG. A combined treatment with COOH-PLL and EG showed high survival rate (more than 90%) of vitrified-warmed COCs after in vitro fertilization. In addition, the fertility and developmental ability of COCs vitrified with E20P10 [EG 20% (v/v) and COOH-PLL 10% (w/v)] or E15P15 group (EG 15% and COOH-PLL 15%) were significantly higher than those with E10P20 (EG10% and COOH-PLL 20%) or P30 group (PLL30%). The vitrified COCs in E20P10 group developed to term at a high success rate (46.2%) and it was significantly higher than that in control (E30) group (34.8%). Our present study demonstrated for the first time that COOH-PLL is effective for vitrification of mouse oocytes.

Role of Different Replacement Fluids During Extracorporeal Treatment in a Pig Model of Sepsis

In an extracorporeal combination therapy, the impact of different replacement fluids on survival was tested in a bacterial sepsis model in pigs. In an animal study 19 pigs, weighing 7.5-11.1 kg, were included. All groups received an intravenous lethal dose of live Staphylococcus aureus over 1 h. The animals were treated by an extracorporeal circuit consisting of online centrifugation and subsequent plasma filtration for 4 h. The extracorporeal circuit was pre-filled with 400 mL replacement fluid. In the P0 group 100% hydroxyethyl starch 130/0.4 was used as replacement fluid; in the P30 group 30% pig plasma and 70% hydroxyethyl starch; and in the P100 group 100% pig plasma. The observation time was 7 days. All animals of the group P100 survived, while all animals of group P0 and five out of seven animals of the P30 group died during the observation time. Extracorporeal therapy consisting of online centrifugation and plasma filtration with 100% pig plasma as replacement fluid significantly improved survival in a pig model of sepsis. Further studies with this approach are encouraged.

The hest interventional time of α7nAChR agonist postconditioning attenuating myocardial ischemia/reperfusion injury in rats

Objective To determine the best interventional time of α7nAChR agonist postconditioning for attenuating myocardial ischemia reperfusion injury in rat in vivo model. Methods Sixty SD rats were randomly divided into six groups(n=10):sham group (S group), ischemia/reperfusion group (I/R group ), α7nAChR agonist postconditioning at onset of reperfusion group( P0group), α7nAChR agonist postconditioning at 30, 60 and 90 min of reperfusion group(P30, P60 and P90 groups). Serum concentrations of TnI, TNF-α and HMGB1 were assayed at 180 min after reperfusion. At the end of experiment, infarction sizes were assessed from excised hearts by Evans blue and triphenyltetrazolium chloride(TTC) staining. Results The infarct sizes(IS％) were (78±16)％ in IR group, (60±7)％ in P0 group, (49±17)％ in P30 group, (54±12)％ in P60 group and (64±15)％ in P90 group, respectively. Serum concentrations of TnI were ( 1.016±0.121 ), (0.168±0.037), (0.156±0.019), (0.194±0.041) and(0.138±0.029) μg/L in these groups respectively. As compared to the S group, serum concentrations of TNF-α in the I/R and P30 groups were significantly increased,TNF-α in the P0 group was significantly reduced. Serum concentration of HMGB1 was significantly higher in the I/R group than that in the S group, but that of all α7nAChR agonist postconditioning groups was significantly lower. As compared with the I/R group, infarct size and serum concentrations of TnI, TNF-α and HMGB1 in all α7nAChR agonist postconditioning groups were significantly reduced. As compared with the P0group, serum concentrations of TNF-α and HMGB1 in the P30, P60 and P90 groups were significantly increased. As compared with the P90 group, in the P30 group, serum concentrations of TNF-α and HMGB1 were significantly increased and IS％ significantly decreased. Conclusion In rat in vivo models of myocardial ischemia reperfusion injury, α7nAChR agonist postconditioning at 30 min of reperfusion could produce the strongest cardioprotection. Key words: Ischemia/reperfusion injury; α7nAChR; Inflammation; Pharmacological postconditioning

ENHANCED FRACTURE AND SOFT-TISSUE HEALING BY MEANS OF ANABOLIC DIETARY SUPPLEMENTATION

Background: Malnutrition is common in hospitalized injured patients. It contributes to delayed fracture-healing and increased morbidity. However, relatively little attention has been directed toward nutritional strategies for augmenting musculoskeletal recovery after a fracture. This animal study was designed to examine the effects of dietary protein intake and the role of conditionally essential amino acids in muscle and bone-healing after a fracture. Methods: One hundred adult male rats were used. Ten rats served as controls and received a 15% protein diet throughout the study. The remaining ninety rats received a 6% protein diet for five weeks to induce protein malnutrition. The rats underwent intramedullary nailing and closed midshaft fracture of one femur. After the fracture, they were separated into three isocaloric dietary groups. Group P6 received a diet with 6% protein; Group P15, a diet with 15% protein; and group P30, a diet with 30% protein with conditionally essential amino acids. At two, four, and six weeks after surgery, ten animals from each group were killed and the femora were evaluated with dual x-ray absorptiometry, histomorphometric assessment of callus, and torsional testing. The quadriceps muscles were analyzed for total mass, total protein content, and for mRNA expression of insulin-like growth factor-1 (IGF-1), IGF-2, IGF receptors, actin, myosin, and vascular endothelial growth factor (VEGF). Results: The P30 group demonstrated elevations in albumin, body mass, muscle mass, total protein content of muscle, and bone mineral density in the fracture callus compared with the P6 diet group at six weeks (p < 0.05). Molecular analysis of muscle revealed that IGF-1, IGF-2, IGF receptors, myosin, actin, and VEGF gene expression were significantly (p < 0.001) higher in the P6 group compared with the P30 group. Biomechanical testing of the femora, however, showed no significant differences. Conclusions: Dietary supplementation with conditionally essential amino acids in malnourished animals had anabolic effects on bone mineralization, body mass, and muscle mass. Clinical Relevance: Identifying methods for augmenting skeletal muscle and fracture-healing by means of oral protein supplementation may provide cost-effective, direct clinical benefits to orthopaedic patients.

Enhanced Fracture and Soft-Tissue Healing by Means of Anabolic Dietary Supplementation

Malnutrition is common in hospitalized injured patients. It contributes to delayed fracture-healing and increased morbidity. However, relatively little attention has been directed toward nutritional strategies for augmenting musculoskeletal recovery after a fracture. This animal study was designed to examine the effects of dietary protein intake and the role of conditionally essential amino acids in muscle and bone-healing after a fracture. One hundred adult male rats were used. Ten rats served as controls and received a 15% protein diet throughout the study. The remaining ninety rats received a 6% protein diet for five weeks to induce protein malnutrition. The rats underwent intramedullary nailing and closed midshaft fracture of one femur. After the fracture, they were separated into three isocaloric dietary groups. Group P6 received a diet with 6% protein; Group P15, a diet with 15% protein; and group P30, a diet with 30% protein with conditionally essential amino acids. At two, four, and six weeks after surgery, ten animals from each group were killed and the femora were evaluated with dual x-ray absorptiometry, histomorphometric assessment of callus, and torsional testing. The quadriceps muscles were analyzed for total mass, total protein content, and for mRNA expression of insulin-like growth factor-1 (IGF-1), IGF-2, IGF receptors, actin, myosin, and vascular endothelial growth factor (VEGF). The P30 group demonstrated elevations in albumin, body mass, muscle mass, total protein content of muscle, and bone mineral density in the fracture callus compared with the P6 diet group at six weeks (p < 0.05). Molecular analysis of muscle revealed that IGF-1, IGF-2, IGF receptors, myosin, actin, and VEGF gene expression were significantly (p < 0.001) higher in the P6 group compared with the P30 group. Biomechanical testing of the femora, however, showed no significant differences. Dietary supplementation with conditionally essential amino acids in malnourished animals had anabolic effects on bone mineralization, body mass, and muscle mass.

Effects of high peak airway pressure on the expression of heat shock protein 70 in rat lungs: a preliminary study

Heat shock protein 70 (HSP70) is induced by a wide variety of stresses in addition to hyperthermia. Recent studies have clarified that mechanical stretching and pressure overload can induce HSP70 in some tissues and cells. However, it remains unclear whether HSP70 is induced in stretch-subjected lungs, such as those under mechanical ventilation. This study was designed to investigate the effects of high peak airway pressure (PAP) ventilation on HSP70 expression in intact rat lungs. Male Sprague-Dawley rats were randomly allocated to one of three groups: non-ventilated (anesthesia alone) control group; PAP 15 cm H(2)O group (P15); and PAP 30 cm H(2)O group (P30). The rats in the PAP groups were subjected to pressure-controlled assisted ventilation at the appropriate PAP for 30 min. Rats were killed at 12, 24 and 48 h after ventilation or anesthesia alone, and the lungs were removed. The lung tissues were processed for immunohistochemical and Western blotting analyses of HSP70. Following 30 min of pressure-controlled assisted ventilation, HSP70 expression in the P30 group was significantly up-regulated in bronchiolar cells and subepithelial tissues at 12 h, and this up-regulation continued throughout the observation period. In contrast, there were no significant differences between the control and P15 groups, although the expression of HSP70 was higher in the P15 group than in the control group at all time points. HSP70 was induced by high PAP ventilation, but its specific role and induction mechanism remain unclear. Therefore, further investigations should be encouraged.

Regional Age-Dependent Effects of Hemineodecortication upon Contralateral Neocortical Thickness: Comparison with Other Measures of Cortical Size

This study investigated age-dependent changes in regional neocortical thickness after hemineodecortication in cats and compared the results to previously reported volumetric and cross-sectional data. Subjects sustained hemineodecortication on postnatal days (P) P10, P30, P60 or in adulthood. Neocortical thickness was quantified at 115 sites along 20 stereotaxic coronal anterior-posterior (AP) planes using defined sites of the main cerebral sulci for the measurements. The analysis established significantly lower thickness values for adult-lesioned as compared to (a) P30, P60 and control groups at AP +14, (b) P30 group at 7 planes along a range of AP +9 to AP +3, and (c) P10 and P60 groups at AP +6. Both the P10 and the P30 groups presented a significantly thicker neocortex than controls at select coronal planes clustering behind AP +10 (parietal and temporal cortices). When analyzed by sulcus, results once again reflected significant advantages for the early-lesioned cats with a significantly thicker cortex found at 4 of the 8 sulci examined. Again, significant advantages were also discovered for early-lesion subjects compared with control cats (splenial, cruciate sulci). Overall, the range of significant effects (from AP +14 to AP 0) and the direction of the means suggested that there was a significant, age-dependent (P10–P60), regional sparing of neocortical thickness with a peak effect occurring at P30. We concluded that: (a) there was a regional sparing/increase of neocortical thickness suggesting that discrete cortical areas are selectively involved in the resistance to structural atrophy following hemineodecortication in young cats (P10–P60) and (b) the global loss of neocortex volume found in our previous study was not apparent using the present thickness measurement. It is suggested that both of these measurements must be taken into account when assessing morphological effects upon the neocortex either in human pathology (i.e. hemispherectomy, intractable epilepsy) or in animal models.

Developmental changes in purinergic calcium signalling in rat neocortical neurones

The changes in cytoplasm free calcium concentration ([Ca 2+] i transients) were measured in Fura-2/AM loaded pyramidal neurones of sensorimotor cortex in acutely prepared slices isolated from 14 days (P14) and 30 (P30) days old rats. Ni 2+ (50 μM) diminished the [Ca 2+] i transients evoked by 50 mM KCl bath application by 47%±8% in neurones of the P14 group and only by 15%±6% in those of P30 group ( P<0.002). Nifedipine and verapamil in concentration 100 μM reduced the calcium transients amplitude triggered by depolarization to about the same extent in both groups of neurons—on average by 50% and 35%, respectively. The amplitude of [Ca 2+] i transients induced by application of 100 μM ATP reached 103±6 nM in P14 neurones and 72±8 nM in the P30 ones. The ATP-[Ca 2+] i induced transient could be evoked in Ca 2+-free external solution, indicating the presence of metabotropic (P2 y) purinoreceptors. Almost all (90%) P14 neurones were endowed with such receptors. At the same time only 1/3 of the tested ( n=42) P30 neurones presented responses to ATP applications in Ca 2+-free solution. The share of ionotropic (P2 x) purinoreceptors in generation of calcium signal was the same in both groups of neurons. No caffeine-induced Ca 2+-release has been observed in the P14 neurons. To the contrary, in 28 cells from 42 investigated neurones of the P30 group application of 40 mM caffeine for 10 s induced considerable [Ca 2+] i transients, which did not disappear in calcium-free solution. A conclusion is made about substantial changes in the expression of Ca 2+-handling mechanisms which are occurring in neocortical neurones at the third–fourth week of postnatal development.

A critical period for reduced brain vulnerability to developmental injury: II. Volumetric study of the neocortex and thalamus in cats

Groups of young adult cats with a left hemineodecortication at postnatal (P) ages (in days) 5–15 (P10), 30 (P30), 60 (P60), 90 (P90), 120 (P120) and in adulthood, were used to measure the volume of the thalamus, bilaterally, and of the remaining neocortex (right hemisphere). The same subjects were employed for the behavioral studies reported in the preceding paper. There was a bilateral, age-dependent, thalamic volume decrease. Ipsilateral to the resection, the thalamic shrinkage was the largest for the adult-lesioned cats (by 56.7%) and it was the smallest for the P30 group (43.3%), with a tendency towards a greater atrophy as the age at lesion increased. A similar pattern of atrophy was seen for the contralateral thalamus but the volume reduction was much less pronounced such that it was significant only for the four older age-at-lesion groups (ranging from 18.2% to 11.2% for the P120 and P90 groups respectively). Once again, the shrinkage was the smallest for the P30 group (5.3%). The remaining neocortex also shrunk in these animals, but the volume decrease was significant only for the adult-lesioned (17.8%) and the P120 group (15.4%), while the P30 group had practically no shrinkage (2.4%). The frontal cortex had no atrophy or it was minimal but the shrinkage gradually increased caudally such that all lesioned groups had some size reduction of the occipital cortex. The present results, together with the main conclusion of the preceding paper, indicate that there is a critical maturation period (CMP) of reduced forebrain vulnerability to neocortical injury which, in cats, tends to end between 30 to 60 days postnatally. The implications for developmental brain damage in other higher mammal species as well as the possible morphological ontogenetical underpinnings of this period are discussed.

Type C RNA virus expression in systemic lupus erythematosus. New Zealand mouse model and human disease

An antigen recognized by antisera produced against p30 (core) proteins of the four chief groups of mammalian type C viruses (murine, feline, RD-114 related to endogenous primate, and infectious primate group) is located in an immune-complex pattern in some renal glomeruli of human SLE patients with lupus proliferative glomerulonephritis but is not detected in normal or pathological control human kidneys. This antigen cross-reacts with p30 interspecies determinants shared by the four chief virus groups and cross-reacts with a partially purified antigen extracted from human SLE spleen. The human SLE spleen antigen cross-reacts with p30 group antigen of RD-114 virus but not of feline or murine viruses. Some host immunoglobulins eluted from a human SLE kidney by acid-buffer show antibody-like activity against p30 group antigen of RD-114 virus but not of simian, feline, or murine viruses.

A p60 polypeptide in the feline leukemia virus pseudotype of Moloney sarcoma virus with murine leukemia virus p30 antigenic determinants.

A 60,000-dalton polypeptide (p60) has been identified in the feline leukemia virus (FeLV) pseudotype of Moloney sarcoma virus [MSV(FeLV)]. This polypeptide is present in the purified virus complex in concentrations greater than either the murine p30 or the feline p27. Purified p60 crossreacts immunologically with murine p30 group antiserum and contains several interspecies determinants, whereas the group specific determinant of FeLV p27 is not detected. Comparison of peptide fingerprints of p60 and murine p30 show many peptides in common. Limited digestion of p60 with either trypsin or chymotrypsin produced p30-35 and p20 peptides which retain the MuLV p30 group and interspecies antigenic activities. The p30 produced by both enzymes comigrates in polyacrylamide gels with the murine p30 of MSV(FeLV), thus suggesting that p60 may be an uncleaved precursor to p30.