[Efficiency analysis on functional protection of nerve plane-oriented laparoscopic total mesorectal excision]

Objective: Using previous total mesorectal excision with pelvic autonomic nerve preservation (PANP+TME) and simple total mesorectal excision (TME) without emphasis on retained nerves as control, we explore the advantages of nerve plane-oriented laparoscopic total mesorectal excision (NPO+LTME) on urinary and sexual function. Methods: A retrospective cohort study was carried out. Case inclusion criteria: (1) male patients with pathologically confirmed middle and low rectal adenocarcinoma (4 to 11 cm from the anus); (2) stage T1-2tumor; (3) normal sexual life before operation. Exclusion criteria: (1) no pathological diagnosis before surgery; (2) local recurrence or distant metastasis; (3) preoperative neoadjuvant chemoradiotherapy; (4) opensurgery and laparoscopic surgery conversionto open; (5) no follow-up data. According to the above criteria, clinical data of 173 male patients with low and middle rectal adenocarcinoma who underwent radical operation for laparoscopic rectal cancer from July 2003 to July 2018 at the Department of Gastrointestinal Surgery, Wuhan University People's Hospital were collected. According to different surgical methods, patients were divided into TME group (58 cases), PANP+TME group (63 cases) and NPO+LTME group (52 cases). There were no significant differences in the baseline data including age, body mass index and pathological examination between the 3 groups (all P>0.05). The nerve plane referred to the nerve, the adipose tissue, the extremely finecapillaries around the nerve with overlying fine membranous tissue. NPO+LTME referred to the process of laparoscopic TME guided by the nerve plane, performing in the loose connective tissue between the nerve plane and the rectal properfascia, in order to ensure the integrity of the nerve plane, and maximally protect the patient's urinary and reproductive functions. The operation time, intraoperative blood loss, urinary catheter removal time, urinary function grading, postoperative first erection time, and erectile function and ejaculation function were observed and compared among the 3 groups at 3- and 6-month after operation. Results: In the NPO+LTME group, the PANP+TME group and the TME group, the operation time was (181.9±24.5) minutes, (176.7±29.2) minutes and (137.7±16.2) minutes, respectively (F=54.868, P<0.001); the intraoperative blood lost was (6.0±1.4) ml, (6.5±1.8) ml and (12.8±4.6) ml, respectively (F=95.016, P<0.001); the time to postoperative removal of the catheter was (2.4±1.1) days, (3.7 ±1.7) days and (6.5±2.4) days, respectively (F=79.409, P<0.001); the first postoperative erection time was (1.6±0.6) days, (8.9±2.7) days and (15.9±6.8) days (F=177.677, P<0.001), respectively, whose differences were all statistically significant (all P<0.01). In comparison of urinary function grading, the proportion of grade I (normal function, no urinary dysfunction) in the NPO+LTME, the ANP+TME group and the TME group was 84.1% (53/63), 39.7% (23/58) and 19.2% (10/52), respectively, and the difference was statistically significant (H=52.915, P<0.001). At postoperative 3- and 6-month, proportion of patients with grade I erectile function (normal erectile function) was 77.8% (49/63) and 85.7% (54/63), 44.8% (26/58) and 53.4% (31/58), 28.8% (15/52) and 48.1% (25/52) in the NPO+LTME group, the PANP+TME group, and the TME group, respectively. The differences were statistically significant (H=91.709, P<0.001; H=79.692, P<0.001). The proportion of patients with grade I ejaculation function (with ejaculation, no abnormalities in routine semen examination before and after surgery) at 3- and 6-month after surgery in the NPO+LTME group, the PANP+TME group and the TME group was 82.5% (52/63) and 87.3% (55/63), 53.4% (31/58) and 60.3% (35/58), 28.8% (15/52) and 46.1% (24/52), respectively. The differences were statistically significant as well (H=86.543, P<0.001; H=78.667, P<0.001). Patients in the NPO+LTME group had no grade III erections and ejaculation disorders. Conclusion: The surgical procedure of NPO+LTME can promote the recovery of postoperative neurological function and preserve urination and sexual function better.

[The effect of pre-pregnancy weight and the increase of gestational weight on fetal growth restriction: a cohort study]

Objective: To investigate the effect of pre-pregnancy weight and the increase of gestational weight on fetal growth restriction. Methods: From May 2013 to September 2014, a total of 3 474 pregnant women who took their first antenatal care and willing to undergo their prenatal care and delivery in Ma 'anshan Maternity and Child Care Centers were recruited in the cohort study. Excluding subjects without weight data before delivery (n=54), pregnancy termination (n=162), twins live births (n=39), without fetal birth weight data (n=7), 3 212 maternal-singleton pairs were enrolled for the final data analysis. Demographic information of pregnant woman, pregnancy history, disease history, height and weight were collected. In the 24(th)-28(th), 32(nd)-36(th) gestational week and childbirth, three follow-up visits were undertaken to collect data of pregnancy weight, pregnancy vomiting, gestational hypertension, gestational diabetes mellitus, newborn gender and birth weight. χ(2) test was used to compare the detection rate of fetal growth restriction in different groups. Multivariate unconditional logistic regression model and spreadsheet were used to analyze the independent and interaction effect of pre-pregnancy weight and the increase of gestational weight on fetal growth restriction. Results: The incidence of fetal growth restriction was 9.7%(311/3 212). The incidence of fetal growth restriction in pre-pregnancy underweight group was 14.9% (90/603), higher than that in normal pre-pregnancy weight group (8.7% (194/2 226)) (χ(2)=24.37, P<0.001). The incidence of fetal growth restriction in inadequate increase of gestational weight group was 17.9% (50/279), higher than the appropriate increase of weight group (11.8% (110/932)) (χ(2)=36.89, P<0.001). Multivariate unconditional logistic regression analysis showed that compared with normal pre-pregnancy weight group, pre-pregnancy underweightwas a risk factor for fetal growth restriction, with RR (95%CI) at 1.76 (1.34-2.32); Compared with the appropriate increase of gestational weight group, inadequate weight increase during pregnancy was a risk factor for fetal growth restriction, with the RR (95%CI) at 1.70 (1.17-2.48). No additive model interaction [relative excess risk of interaction, attributable proportions of interaction, the synergy index and their 95%CI were 0.75 (-2.14-3.63), 0.21 (-0.43-0.86) and 1.43 (0.45-4.53), respectively] or multiplication model interaction (RR (95%CI): 1.00 (0.44-2.29)) existed between pre-pregnancy underweight and inadequate increase of gestational weight on fetal growth restriction. Conclusion: Pre-pregnancy underweight and inadequate increase of gestational weight would increase the risk of fetal growth restriction without interaction.

Association between Excess Bodyweight and Intake of Red Meat and Vegetables among Urban and Rural Adult Chinese in Nanjing, China

The objective of this study was to examine the association of red meat and vegetable consumption with excess bodyweight. This is a cross sectional study, conducted between October 2000 and March 2001. Participants included 23,316 local residents aged 35 and above from 45 administrative villages randomly selected from urban and rural areas of Nanjing, China, with a population of 5.6 million. The response rate was 90.1%. Logistic regression model was used for the analysis. The prevalence of excess body weight, overweight and obesity was 34.1%, 28.2% and 6.0%, respectively. After adjustment for age, educational attainment, family average income, occupational and leisure-time physical activity, smoking, drinking, consumption of white meat, consumption of rice and cooking oil as well as fruits, participants in the moderate or higher level of red meat consumption were more likely to have excess body weight (OR: 1.13 (95% CI=1.02, 1.26) and 1.15 (1.02, 12.9) for males; 1.11 (0.98, 1.25) and 1.25 (1.10, 1.42) for females respectively), compared with those in the lower level of red meat consumption. There was no statistically significant association for consumption of vegetables. Consumption of more red meat was suggested to be a factor contributing to body weight gain in China. For residents who want to have healthy body weight, it is important to consume less red meat in the process of socioeconomic transition. Asia Pac J Public Health 2007; 19(3): 3-9.

[Research progress of health effect of polybrominated diphenyl ethers]

Polybrominated diphenyl ethers (PBDEs) was one of the most common brominated flame retardants, it has been widely used in products such as furnitures, polymer and plastical material, textiles, electronic products and building materials. PBDEs have potential effect such as neurodevelopmental toxicity, reproductive toxicity, thyroid toxicity, immunological toxicity, embryo toxicity, liver toxicity, teratogenicity and potential carcinogenicity. This paper was aimed to review the environmental exposure way, current level, neurotoxicity, neurodevelopmental toxicity and reproductive toxicity of PBDEs. In recent years, PBDEs has been detected in environment, wildlife animal and human body around the world, there were the significant differences of exposure levels of PBDEs. The most abundant congener were tetra-BDE or BDE-47, hexa-BDE or BDE-153, and deca-BDE or BDE-209. Prenatal exposure to PBDEs has great impact on the infants' neurodevelopmental function, induces changes in neuropsychological developmental behavior, decreases of congnition, motivation and attention. High levels of PBDEs have positive relationship with Luteinizing hormone levels, testis disfunction and children's cryptorchidism, and have negative relationship with sperm number and testis size.

Unusual parotid gland lesions: a pictorial review

This is a pictorial essay of unusual parotid gland lesions that may be encountered in routine clinical practice.

Analysis of three marine fish cell lines by rapd assay

We tested the applicability of the random amplified polymorphic deoxyribonucleic acid (RAPD) analysis for identification of three marine fish cell lines FG, SPH, and RSBF, and as a possible tool to detect cross-contamination. Sixty commercial 10-mer RAPD primers were tested on the cell lines and on samples collected from individual fish. The results obtained showed that the cell lines could be identified to the correspondent species on the basis of identical patterns produced by 35-48% of the primers tested; the total mean similarity indices for cell lines versus correspondent species of individual fish ranged from 0.825 to 0.851, indicating the existence of genetic variation in these cell lines in relation to the species of their origin. Also, four primers, which gave a monomorphic band pattern within species/line, but different among the species/line, were obtained. These primers can be useful for identification of these cell lines and for characterization of the genetic variation of these cell lines in relation to the species of their origin. This supported the use of RAPD analysis as an effective tool in species identification and cross-contamination test among different cell lines.

[Multiplication of the shrimp baculovirus HHNBV with primary cell cultures from lymphoid organ of Penaeus chinensis]

The hypodermal and hematopoietic necrosis baculovirus HHNBV has been confirmed to be the causative agent for the explosive epidermic disease of farmed shrimp Penaeus chinensis since 1993. The virus was isolated and multiplied successfully in the primary cell cultures from the lymphoid organ of the shrimp. A cell monolayer was formed in three days in the medium MPS and could be maintained for 1-3 months as the medium replaced every 4-5 days. The cytopathic effect occurred in 5 days after inoculation of the tissue extract from the diseased shrimp. The transmission electron microscopy showed many rod-shaped virions of HHNBV in the nuclei of infected cells.

Lifetime low-level exposure to environmental lead and children's emotional and behavioral development at ages 11-13 years. The Port Pirie Cohort Study

The Port Pirie Cohort Study is the first study to monitor prospectively the association between lifetime blood lead exposure and the prevalence of emotional and behavioral problems experienced by children. Lead exposure data along with ratings on the Child Behavior Checklist were obtained for 322 11-13-year-old children from the lead smelting community of Port Pirie, Australia. Mean total behavior problem score (95% confidence interval (CI)) for boys whose lifetime average blood lead concentration was above 15 microg/dl was 28.7 (24.6-32.8) compared with 21.1 (17.5-24.8) in boys with lower exposure levels. The corresponding mean scores (95% CI) for girls were 29.7 (25.3-34.2) and 18.0 (14.7-21.3). After controlling for a number of confounding variables, including the quality of the child's HOME environment (assessed by Home Observation for Measurement of the Environment), maternal psychopathology, and the child's IQ, regression modeling predicted that for a hypothetical increase in lifetime blood lead exposure from 10 to 30 microg/dl, the externalizing behavior problem score would increase by 3.5 in boys (95% CI 1.6-5.4), and by 1.8 (95% CI -0.1 to 11.1) in girls. Internalizing behavior problem scores were predicted to rise by 2.1 (95% CI 0.0-4.2) in girls but by only 0.8 (95% CI -0.9 to 2.4) in boys.

Tributyltin distribution in the coastal environment of Peninsular Malaysia

The occurrence of tributyltin (TBT) is reported in the coastal waters of a few selected sites in Peninsular Malaysia. Water, bivalves and sediment samples collected were analysed specifically for TBT using sensitive analytical methods which involved a solvent extraction procedure with appropriate clean-up followed by graphite furnace atomic absorption spectrometric measurements. The levels of TBT in the seawater in unexposed areas were found in the range from <3.4 to 20 ng litre(-1) as compared to coastal areas with high boat and ship activities where TBT levels in seawater were generally above 30 ng litre(-1), with the highest level found at 281.8 ng litre(-1). TBT levels in the tissues of random cockle and soft-shell clam samples from local markets were found in the range from <0.5 to 3.7 ng g(-1) wet weight. The levels of TBT found in green mussel samples both from the market (23.5 ng g(-1) wet weight) and those from a mussel farm (14.2 ng g(-1) wet weight) indicate slight accumulation of TBT. In sediments, TBT levels were found ranging from <0.7 ng g(-1) dry weight in unexposed coastal sites to as high as 216.5 ng g(-1) dry weight for a site within a port area.

Environmental exposure to lead and children's intelligence at the age of seven years. The Port Pirie Cohort Study

BACKGROUND

Exposure to lead in early childhood is thought to result in delayed neuropsychological development. As yet there is little longitudinal evidence to establish whether these effects persist into later childhood.

METHODS

We measured IQ scores in 494 seven-year-old children from the lead-smelting community of Port Pirie, Australia, in whom developmental deficits associated with elevated blood lead concentrations had already been reported at the ages of two and four years. Exposure to lead was estimated from the lead concentrations in maternal blood samples drawn antenatally and at delivery and from blood samples drawn from the children at birth (umbilical-cord blood), at the ages of 6 and 15 months and 2 years, and annually thereafter. Data relating to known covariates of child development were collected systematically for each child throughout the first seven years of life.

RESULTS

We found inverse relations between IQ at the age of seven years and both antenatal and postnatal blood lead concentrations. After adjustment by multiple regression for sex, parents' level of education, maternal age at delivery, parents' smoking status, socioeconomic status, quality of the home environment, maternal IQ, birth weight, birth order, feeding method (breast, bottle, or both), duration of breast-feeding, and whether the child's natural parents were living together, the relation with lead exposure was still evident for postnatal blood samples, particularly within the age range of 15 months to 4 years. For an increase in blood lead concentration from 10 micrograms per deciliter (0.48 mumol per liter) to 30 micrograms per deciliter (1.45 mumol per liter), expressed as the average of the concentrations at 15 months and 2, 3, and 4 years, the estimated reduction in the IQ of the children was in the range of 4.4 points (95 percent confidence interval, 2.2 to 6.6) to 5.3 points (95 percent confidence interval, 2.8 to 7.8). This reduction represents an approximate deficit in IQ of 4 to 5 percent.

CONCLUSIONS

Low-level exposure to lead during early childhood is inversely associated with neuropsychological development through the first seven years of life.

Effects of maternal smoking upon neuropsychological development in early childhood: importance of taking account of social and environmental factors

Data from a prospective study of 548 children followed from birth to 4 years of age were analysed to determine whether maternal smoking during and/or after pregnancy affects children's neuropsychological development. The differences in mean developmental test scores between children whose mothers smoked and those of mothers who did not smoke were slight, with subscale scores only 2.4 to 4.1% lower in children whose mothers smoked. These differences were not statistically significant after adjustment for socio-economic status, quality of home environment and mother's intelligence, suggesting that the social and environmental factors are major confounders of the association of exposure to maternal smoking and neuropsychological development in childhood. In order to gain a better understanding of this area, more precise measures of exposure to environmental tobacco smoke and comprehensive consideration of confounders will be required.

Sociodemographic factors modifying the effect of environmental lead on neuropsychological development in early childhood

A long-term prospective cohort study was conducted to examine the association between prenatal and postnatal exposure to environmental lead and childhood neuropsychological development. The possible interactive effects of blood lead and some covariates on early development were explored in this study. Our data suggest that gender of the child modifies the effect of lead on the neuropsychological development during early childhood. At the ages of 2 and 4 years, girls appear to be more sensitive than boys to the neuropsychological effects of lead. However, there is no significant modification of the effect of lead by some other covariates, such as parental smoking, socioeconomic status, home environment, birth weight, and the kind of infant feeding. Evidence of interactions between environmental lead exposure and other covariates in the causation of neuropsychological deficits in childhood underscores the desirability of considering both main effects and interactions in this area of research. Such effects, if confirmed, may have implications for public health intervention strategies.

Determinants of blood lead concentrations to age 5 years in a birth cohort study of children living in the lead smelting city of Port Pirie and surrounding areas

Sources of variation and some principal determinants of blood lead concentration (PbB) were investigated in a cohort of children, followed to age 5 y, who were born near a lead smelter in Port Pirie, South Australia. The child's age and place of residence were the two variables most strongly predictive of PbB. A sharp increase in PbB occurred between 6 and 15 mo of age and was followed by a peak concentration that occurred at approximately 2 y of age, after which PbB steadily and consistently declined. Irrespective of age, the PbBs in children who lived in Port Pirie were significantly higher than levels identified in children who resided outside the city. There was no significant difference in PbB between boys and girls. Elevated PbB at each specific age was associated mainly with increased lead concentrations in the topsoil of the local residential area, employment of the father in the lead industry, parental smoking, and behaviors likely to cause ingestion of dirt. Blood samples taken from children at certain ages and during the warmer months contained more lead than samples obtained during the cooler months. The effects of these determinants on PbB during early childhood were basically consistent in both single and multivariable analyses.

Chronological changes in genetic variance and heritability of anthropometric characteristics among Chinese twin infants

In order to examine the chronologic changes in genetic variance and heritability of anthropometric characteristics of Chinese infants in Taiwan, a total of 521 pairs of same-sexed twin neonates given birth in four major general teaching hospitals in Taipei City were studied. Based on the placental pattern and 12 red blood cell antigens, 428 MZ and 93 DZ twin pairs were identified and followed up to the age of one year. There was no significant genetic variance for all anthropometric characteristics adjusted for sex and gestational week before the age of six months. After adjusting for sex and gestational week, a significant genetic variance was observed at the age of six months, with heritability values of 0.51 (weight), 0.63 (head circumference), 0.77 (chest circumference), and 0.53 (arm circumference), as well as at one year, although with considerably lower heritability values. This implies that growth is dynamically determined by both genetic and environmental factors during infancy.

Genetic variance and heritability of temperament among Chinese twin infants

In order to examine the genetic variance and heritability of temperament among Chinese infants in Taiwan, a total of 62 pairs of same-sexed twin infants given birth in four major general teaching hospitals in Taipei City were studied. Based on placentation and 12 red blood cell antigens, 44 MZ and 18 DZ pairs were identified. Temperament was assessed at the age of six months by the Chinese edition of Carey's Temperament scale. Significant genetic variance was observed for activity level, approach or withdrawal, intensity of reaction, quality of mood, and threshold of responsiveness, with a heritability of 0.64, 0.56, 0.74, 0.39, and 0.45, respectively. There was no significant intrapair difference in temperamental characteristics between monochorionic and dichorionic MZ twins.

Chronological changes in genetic variance and heritability of systolic and diastolic blood pressure among Chinese twin neonates

In order to examine the chronological changes in genetic variance and heritability of arterial systolic and diastolic blood pressure (SBP and DBP of Chinese infants in Taiwan, a total of 339 same-sexed twin neonates born in four major general teaching hospitals in Taipei City were studied. Based on placentation and 12 red blood cell antigens, 274 monozygotic (MZ) and 65 dizygotic (DZ) twin pairs were identified and followed up to the age of one year. Both SBP and DBP were measured by Doppler blood pressure monitor. Within-pair mean squares of SBP and DBP were consistently smaller in MZ than DZ twins at ages one month and over. The findings remained unchanged after the adjustment for the effects of age, sex, gestational age, placentation and physical state during blood pressure measurement. Falconer's heritability indices for adjusted SBP and DBP at ages two months and over ranged from 0.29 to 0.55 and from 0.27 to 0.45, respectively. The study indicates an important genetic influence on blood pressure during infancy.

Genetic variance and heritability of serum cholesterol and triglycerides among Chinese twin neonates

In order to examine the genetic variance and heritability of serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides, a total of 349 pairs of same-sexed twin neonates born in four major general teaching hospitals in Taipei City were studied. Based on the placental pattern and 12 red blood cell antigens, 271 monozygotic (MZ) and 78 dizygotic (DZ) twin pairs were identified. There was a significant genetic variance for total cholesterol, HDL-C, LDL-C, and triglycerides both unadjusted and adjusted for sex, gestational age and placentation. The unadjusted heritability of total cholesterol, HDL-C, LDL-C, and triglycerides was 0.59, 0.30, 0.25 and 0.75, respectively; while the corresponding adjusted heritability was 0.74, 0.38, 0.31, and 0.49, respectively. Intrapair variance of serum lipids was not significantly different between monochorionic and dichorionic MZ twins.

Patterns of copper loss--a comparison of the multiload Cu250, TCu-220C and Cu7 IUDs

The rate of copper loss from 329 IUDs (Multiload Cu250, TCu-220C and Cu7) which had been terminated for various reasons after 0.5-46 months in-utero were determined. All 3 IUDs showed a wide scatter of release rates with no significant differences between the ML Cu250 and the Cu7. The TCu-220C showed the highest rates and in contrast to the ML Cu250 and Cu7, the decrease with time was not significant. Its rate of copper loss was significantly higher than the ML Cu250 in the 1st year, but comparable after that. The TCu-220C had a similar rate to the Cu7 in the 1st year and significantly higher rates subsequently. The relevance of these findings to observed pregnancy rates and area of copper on the IUDs is discussed.

Central organization of eighth nerve and mechanosensory lateral line systems in the brainstem of ictalurid catfish

The octavolateral sensory systems in teleost fish comprise at least four distinct hair-cell sensory modalities which are processed separately within the CNS. Two of these modalities, the mechanosensory lateral line system and the eighth nerve auditory system, have been implicated in the animal's ability to detect and localize underwater vibrations. Distinct mechanosensory lateral line and auditory nuclei are present within the torus semicircularis, the midbrain homologue of the inferior colliculus. The present study utilized horseradish peroxidase tracing techniques to delineate those areas of the lower brainstem which are involved in auditory as opposed to mechanosensory lateral line processes. The primary mechanosensory nucleus of the medulla, n. medialis, projects directly to the optic tectum and to the mechanosensory nucleus of the torus semicircularis. Nucleus medialis receives input from primary lateral line nerve fibers as well as from a number of sites within the CNS: n. praeeminentialis pars ventralis, and the eminentia granularis and lobus caudalis of the cerebellum. The n. praeeminentialis itself receives a descending input from the mechanosensory nucleus of the torus semicircularis. These mechanosensory lateral line pathways are parallel to, but distinct from, those of the electrosensory lateral line system. Auditory signals reach the midbrain via an entirely separate route. The octaval nerve terminates in a column of five medullary nuclei. Of these, only the anterior and descending octaval nuclei maintain a direct but sparse projection to the auditory nucleus of the midbrain. The bulk of the auditory input to the midbrain involves a newly described medullary nucleus, the medial auditory nucleus of the medulla. This nucleus receives input from the descending octaval nucleus and projects bilaterally to the auditory nucleus of the torus semicircularis. It is suggested that the medial auditory nucleus of the medulla is homologous to portions of the superior olivary complex of other vertebrates.

Physiological properties of the electro- and mechanoreceptors in catfish Ictalurus nebulosus

Two kinds of afferents in the posterior lateral line nerve in catfish have been identified according to their functional properties: the electro- and mechanoreceptor afferents. The electroreceptor afferents are very sensitive to electric current in water. They do not respond to distant mechanical stimulation resulting from water dropping into the tank, but do respond to light pressing against the receptors with a glass rod. The mechanoreceptor afferents are very sensitive to distant mechanical events, but much less sensitive to electric current.

Establishment of a murine cell line resistant to arabinosyladenine and devoid of adenosine deaminase activity

A population of cells stably resistant to a concentration of arabinosyladenine 100-fold greater than that tolerated by wild-type cells was selected over a period of 15 months. The cells are not cross resistant to arabinosylcytosine and may have at least one kinase with altered substrate specificity.

Central organization of the electrosensory lateral line system in bullhead catfish Ictalurus nebulosus

The connections of the electrosensory lateral line lobe (ELL) of ictalurid catfish were examined by means of horseradish peroxidase tracing methods. The ELL receives direct input from the anterior and posterior lateral line nerves. Some of these nerve fibers continue through the ELL to end as mossy fibers in the lateral portion of the eminentia granularis. Granule cells in this area as well as those in lobus caudalis of the cerebellum project back to the ELL as parallel fibers in the upper molecular layer. The lower molecular layer of the ELL receives its input from the n. praeeminentialis. The ELL projects via the lateral lemniscus to the n. praeeminentialis and torus semicircularis bilaterally, but more heavily on the contralateral side. In addition, the n. praeeminentialis receives the bulk of its input from the ipsilateral torus semicircularis. The caudal lobe of the cerebellum both projects to the electrosensory portion of the torus semicircularis and receives indirect input from the torus semicircularis via the anterior olivary nucleus. In summary, the central organization of this ampullary receptor electrosensory system in catfish is similar to that of the ampullary-tuberous receptor electrosense of mormyrids and gymnotids.

Autoradiographic method for detection of lactate dehydrogenase-elevating virus-infected cells in primary mouse macrophage cultures

Peritoneal cells from starch-injected Swiss mice were propagated in plastic petri dishes and on cover slips in a mouse L-cell-conditioned medium for 12 to 24 h and then infected with various multiplicities of lactate dehydrogenase-elevating virus (LDV). Over 95% of the cells in these cultures phagocytosed latex particles and were, therefore, considered macrophages. Infected and mock infected macrophage cultures were supplemented with [3H]uridine at various times after infection and with actinomycin D 30 min before addition of the [3H]uridine. After 1 or 2 h of further incubation, plate cultures were analyzed for LDV-specific RNA, and cover slip cultures were investigated by autoradiography. Other cultures were labeled in the absence of actinomycin D, and the culture fluid was analyzed for labeled LDV. There was a good correlation between the production of LDV-specific RNA and LDV and the number of heavily labeled cells in these cultures. The labeled cells in these cultures. The labeled cells, therefore, were equated with productively infected cells. Only a maximum of about 20% of the macrophages, however, became heavily labeled regardless of the multiplicity of infection or the time, after infection, at which the cells were exposed to [3H]uridine. Only background labeling was observed in the remainder of the cells and in mock-infected cells treated with actinomycin D. The highest proportion of labeled cells was observed when the cells were infected with a multiplicity of infection of about 2,000 mouse infectious units per cell and labeled from 6 to 8 h after infection. Thereafter, the proportion of productively infected cells decreased progressively, concomitant with a decrease in the amounts of viral specific RNA and of LDV produced by the cultures. The results indicate that the majority of the macrophages in primary macrophage cultures do not support LDV replication. Their nonpermissiveness may depend on the physiological state of the cells or reflect the presence of subpopulations of macrophages, but no morphological differences between productively infected an uninfected cells were detectable.