Hepatic Sarcoidosis: Diagnostic approach and management

Sarcoidosis is a multi-systemic, non-caseating granulomatous disorder with an idiopathic aetiology. We report a 58-year-old Malay woman, with underlying type II diabetes mellitus, hypertension and history of stage II pulmonary sarcoidosis presenting with incidental finding of multiple hypodense liver lesions. Her recent contrasted enhanced computed tomography of the abdomen and pelvis demonstrated multiple intra-abdominal lymphadenopathies with evidence of liver and splenic infiltrations. Her ageappropriate malignancy screening was negative while liver biopsy showed non-caseating granulomatous hepatitis consistent with hepatic sarcoidosis. In view of her normal liver enzymes and normalised serum calcium levels, no immunosuppressive therapy was commenced. She remains asymptomatic and is currently under our close monitoring.

Dietary Flavonoids Luteolin and Quercetin Inhibit Migration and Invasion of Squamous Carcinoma through Reduction of Src/Stat3/S100A7 Signaling

Flavonoids are well-known antioxidants and have shown the ability to prevent tumor formation and recurrence. Especially in dietary flavonoids, they have provided convenience and consistence of intake for long-term prevention of tumor formation. Previous reports suggested that S100 calcium-binding protein A7 (S100A7) might activate epithelial–mesenchymal transition (EMT) signaling and promote the metastasis of tumor cells; however, the regulatory signaling was unclear. In this study, we found that S100A7 was highly expressed in cancer cells and could be reduced by luteolin (Lu) and quercetin (Qu) through Src/Stat3 signaling. We found that the protein levels of S100A7, phosphorylated Src (p-Src), and p-Stat3 were increased in A431-III cells. Flavonoids Lu and Qu reduce protein levels of p-Src, p-Stat3 and S100A7 in A431-III cells. Treatment of A431-III cells with Src inhibitor SU6656 and Stat3 inhibitor S3I-201 also reduced the protein levels of S100A7. Transactivation activity of 5′-upstream regions of S100A7 was activated by Stat3 but was reduced by treatment with Lu, Qu, SU6656 and S3I-201. The treatment also reduced the migratory and invasive abilities of A431-III cells. In a further analysis of EMT markers, the protein level of E-cad increased and that of Twist decreased after treatment with the inhibitors and flavonoids. Overexpression of S100A7 decreased the protein level of E-cad and increased the Twist level, whereas knockdown of S100A7 had the opposite effects. Treatment with S3I-201, Lu and Qu, compared to the control, were found to decrease metastasis of tumor cells in zebrafish larvae. These results suggest that Lu and Qu may inhibit Src/Stat3/S100A7 signaling to reduce tumorigenesis of cancer cells.

Emergency embolization of spontaneous ruptured hepatocellular carcinoma: correlation between survival and Child-Pugh classification

From February 1994 to April 2000, 29 emergency gelfoam embolizations for spontaneous ruptured hepatocellular carcinoma (HCC) performed in 28 patients were retrospectively reviewed. There were 11 patients in Child's A, 11 in Child's B and six in Child's C classification of cirrhosis. The duration of the procedure, artery embolized and complications were reviewed, and the Child-Pugh classification of each patient was correlated with their mean survival period. Embolization was done in 12 right hepatic arteries, two left hepatic arteries and 15 proper hepatic arteries. In one patient, the left hepatic artery was embolized initially but the proper hepatic artery was also embolized because another subcapsular liver tumour was found after reviewing the preangiogram CT scan. The entire procedure took 40-170 min (mean = 86 min) with no periprocedural complication. Following embolization, the mean survival period for Child's A class was 218.3 days, Child's B class was 83.4 days and Child's C class was 11.0 days. Transcatheter embolization is an effective treatment to arrest bleeding in spontaneous ruptured HCC. Patients with Child's A class cirrhosis have the longest survival. Selective embolization of either the right or the left hepatic artery alone carries the potential risk of missing multifocal HCC that might not be easily appreciated during angiography.

Molecular cloning of a teleost growth hormone receptor and its functional interaction with human growth hormone

This paper reports the first full-length cDNA sequence of a growth hormone receptor (GHR) from a teleost fish and its functional expression in cultured eukaryotic cells. The cDNA sequence, from Carassius auratus (goldfish), encodes a protein of 602 amino acids (aa) akin in architecture to the GHRs of other species. Despite the presence of motifs characteristic of GHR, the overall homology between the goldfish GHR and other GHRs is very low ( approximately 40% aa identity). CHO cells transfected with this receptor cDNA can be stimulated to proliferate by human growth hormone (hGH). In addition, the transfected cells can transactivate a co-expressed mammalian serine protease inhibitor (Spi) 2.1 promoter upon stimulation by hGH, indicating the successful interaction of the fish receptor with the mammalian ligand to evoke the down-stream post-receptor events. Tissue distribution studies indicated that the receptor is mostly expressed in the liver and hypothalamus of goldfish. A single mRNA transcript of a size of about 4 kb was found in the goldfish liver.

Interactions between a lipase and charged surfactants--a comparison between bulk and interfaces

The interaction between a charged surfactant and a lipase has been investigated by several methods. Interactions in aqueous bulk phase was studied by NMR and by microcalorimetry. Surface tension and neutron reflectivity were used for studies at the air-water interface. Interactions at the interface between a hydrophobic solid surface and water was investigated by ellipsometry. The results obtained are as follows. The cationic surfactant, tetradecyltrimethylammonium bromide (iodide in the NMR experiments), showed strong interaction at the air-water and the hydrophobic solid-water interfaces but no clear indication of an interaction in bulk phase was seen. The anionic surfactant showed no interaction with the lipase neither at the interfaces, nor in bulk. The difference in behavior of the system cationic surfactant-lipase in bulk and at the interfaces may be due to the change in enzyme conformation that is known to occur at interfaces between water and an apolar phase.

Molecular cloning and expression studies of a prolactin receptor in goldfish (Carassius auratus)

A full-length cDNA clone, of a size of 4.6 kb, for the goldfish prolactin receptor has been isolated. This cDNA clone encodes a protein of 600 amino acids homologous to prolactin receptors of other species. A Kyte-Doolittle hydropathy analysis of the receptor indicates that the translated protein consists of a signal peptide of 22 amino acids, an extracellular domain of 228 amino acids, a single transmembrane domain of 24 amino acids, and an intracellular domain of 346 amino acids. Several characteristic landmarks of prolactin receptor could be identified in this clone. These include the four conserved cysteine residues and the WS motif within the extracellular domain, and the box 1 and box 2 regions of the intracellular domain. Among all the prolactin receptor sequences known to date, this clone bears the closest resemblance to the tilapia prolactin receptor, although homology between these two fish prolactin receptors is rather low. There are only 57.4% of nucleotide and 48.3% of amino acid sequence identities between these two fish receptors. This receptor cDNA was transfected into CHO-K1 cells for functional analysis. RT-PCR analysis with a pair of gene specific primers indicate that the receptor was transcribed in the transfected cells. Using a cell proliferation assay based on the reduction of the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, the receptor transfected CHO-K1 cells can be stimulated to proliferate upon the addition of ovine prolactin in the culture medium. The tissue distribution of the prolactin receptor in goldfish was studied by RT-PCR/Southern analysis and by Northern analysis. The results indicated that the receptor is expressed mostly in the kidney, the gill and the intestine of goldfish, corroborating with the osmoregulatory role of prolactin in fish. In addition, an appreciable level of the receptor is also found in the brain and gonads of goldfish. Northern analysis showed that there are two transcript sizes, a major 4.6 kb and a minor 3.5 kb mRNAs, in the kidney, gill and intestine.

Differences in diagnostic approach between family physicians and other specialists in patients with unintentional body weight loss

BACKGROUND

Unintentional weight loss is a diagnostic dilemma with diverse diagnostic possibilities for physicians.

OBJECTIVES

Our study focused on the evaluation of differences in diagnostic approach between family physicians and physicians in other specialties.

METHODS

Outpatients who visited National Taiwan University Hospital from January 1996 to December 1996 with unintentional weight loss of 5% or more within 6 months were recruited by a computer search. All data were obtained from a structured medical record audit.

RESULTS

There was no significant difference in the utilization of common diagnostic laboratory tests between the two groups. However, other specialists ordered more carcinoembryonic antigen tests (P < 0.01) and hepatitis B antigen tests (P < 0.05), but fewer upper gastrointestinal tract barium studies (P < 0.05) than family physicians. For patients without a definite final diagnosis, the diagnostic total costs for laboratory tests and imaging studies were lower for family physicians than other specialists (P < 0.01). For patients with biomedical disorders, the diagnostic cost was not significantly different between the two groups. For patients with psychological disorders, the costs for imaging studies were lower for family physicians than for other specialists (P < 0.05) but there was no significant difference in the total costs between these two groups.

CONCLUSIONS

We conclude that the different approaches between the two groups are due to different training backgrounds and characteristics of practice. The patient-centred concepts of family physicians might be more cost-effective in dealing with undifferentiated problems.

Polyelectrolyte brushes: counterion distribution and complexation properties

The structure of dense grafted polyelectrolyte layers has been studied with a combination of neutron reflectivity and infrared spectroscopy techniques. The polyelectrolyte brushes were made of poly(styrene sulfonate) neutralized by different counterions. Small counterions are distributed throughout the brush in order to ensure a highly local electroneutrality. In addition, they can be readily exchanged with other small ions. On the other hand, macromolecular counterions (as well as some proteins) are irreversibly trapped by the brush, but are located outside the grafted layer and cannot reach the surface.

A study of the noise hazard to employees in local discotheques

AIM OF STUDY

There is growing concern that amplified music in discotheques can cause hearing loss. This study attempts to evaluate the noise hazard of employees exposed to amplified music in our discotheques.

METHOD

Employees comprising of disc jockeys, bartenders, waiters, cashiers and security officers of five selected discotheques were used for the study. Personal noise dosimetry was carried out on 40 employees throughout their workshift. The audiometric examination results of another 46 employees were compared with 37 subjects from a non-exposed match control group.

RESULTS

The range of exposure to noise level above 85 dBA for the employees is 3.6 to 6.9 hours with a mean of 5.1 hours. All the occupational groups are exposed to noise level of at least 89 dBA Leq for their whole work shift. The discotheque group has statistically significant higher prevalence (41.9%) of early sensorineural hearing loss compared to the control group (13.5%). A higher proportion of employees in the older age group (above 30 years old) and working longer (above 1 year) suffer from hearing loss. A significant proportion of the discotheque study subjects (21%) also complained of recurrent tinnitus compared to 2.7% in the control group. The younger (< 30 years) and those with shorter exposure duration (< 1 year) appeared to complain of tinnitus more.

CONCLUSION

The study shows that all the employees regardless of occupations are exposed to noise above the permissible level of 85 dBA Leq A high proportion of them also suffer from early sensorineural hearing loss and tinnitus.

Mortality trends of elderly people in Taiwan from 1974 to 1994

BACKGROUND

the hypothesis that disability and death will eventually be compressed to a period late in life needs empirical confirmation.

OBJECTIVES

we have examined the secular trends of life expectancy and common causes of death in the aged population of Taiwan.

METHOD

we compared the life expectancy, causes of death and probability of death for people at birth, at age 65 and at age 85 for both sexes from 1974 to 1994 using data from Taiwan government statistics.

RESULTS

there has been a substantial gain in life expectancy, especially for men age 85 and over, in the past 20 years. . Mortality due to stroke, ischaemic heart disease, hypertension and chronic pulmonary disease has declined. There has been a steep increase in cancer deaths and deaths associated with diabetes mellitus. Tuberculosis and injury-related deaths have declined but pneumonia deaths have increased. For elderly people, the probability of dying from cancer and ischaemic heart disease increased with time. However, the probability of dying from stroke decreased. Although there was a decrease in probability of deaths associated with falls, there was an increase of deaths due to 'frailty' (as judged by falls, pneumonia and septicaemia).

CONCLUSIONS

cancer is a major cause of death in the elderly population of Taiwan. This rapidly expanding elderly population seemed to suffer from poorer health in the later period of their life.

A case-control study on risk factors for Type 1 diabetes in Taipei City

To search for non-genetic risk factors for Type 1 diabetes among Chinese, a total of 117 Type 1 diabetes patients identified from the Taipei Type 1 Diabetes Registry and 193 frequency-matched controls with normal glucose tolerance were recruited. The controls were selected from classmates or colleagues of cases with similar distributions of age, sex, and parental and individual educational levels. Information on Type 1 diabetes risk factors was obtained through standardized interviews according to a structured questionnaire administered by two trained nurses. In the univariate analyses, the order of pregnancy of the study subject, the number of spontaneous and induced abortions reported by the mother before giving birth to the study subjects, the duration of breast-feeding and monthly family income were significantly associated with Type 1 diabetes in a dose-response manner. There was a U-shaped relationship with Type 1 diabetes for birth weight and paternal age at the conception of the study subjects. After further adjustment for multiple risk factors through logistic regression analysis, the biological gradient for pregnancy order, duration of breast-feeding, and the U-shaped relationship for paternal age remained statistically significant.

Identification of cryptic peanut agglutinin-reactive sites in human lipoprotein(a)

After treatment of human lipoprotein(a) (Lp(a)) with neuraminidase, formerly cryptic sites became available for binding to peanut agglutinin (PNA) lectin and a Thomsen-Friedenreich antigen (T-antigen)-specific monoclonal antibody. The PNA-reactive sites were localized to the apo(a) moiety of Lp(a) and O-specific carbohydrate side chains. Lp(a) with larger isoforms of apo(a) contained more potential PNA reactivity per molecule of Lp(a) apoB than did smaller isoforms. Very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL) did not contain comparable amounts of the cryptic PNA-reactive sites.

[Community-based hepatocellular carcinoma screening in seven townships in Taiwan]

The early detection and prompt treatment of hepatocellular carcinoma (HCC) may prolong life and improve the quality of life of affected patients. In order to compare sensitivity and specificity of various screening biomarkers, identify subjects with a high risk of developing HCC, and estimate prevalence and incidence of HCC among subjects, a community-based HCC screening program was implemented in Sanchi, Chutung, Potzu, and Kaohsu, Taiwan Island as well as Makung, Huhsi and Paihsa in Penghu Islets. First stage screening of HCC was based on serological markers including hepatitis B surface antigen (HBsAg), antibody against hepatitis C virus (anti-HCV), alpha-fetoprotein (AFP > or = 20 ng/mL), alanine transaminase (> or = 40 IU/L), and aspartate transaminase (> or = 45 IU/L); as well as history of liver cirrhosis or HCC among first-degree relatives. Subjects who were positive for at least one of above six first-stage criteria were referred for second-stage screening by abdominal ultrasonography. Confirmatory diagnosis of HCC was made in suspicious cases according to aspiration cytology surgical pathology, digital substracted angiogram and/or computed tomography. A total of 12,026 men in seven study townships and 1,800 women in two townships in Penghu were recruited for first-stage screening (response rate: men, 25.5%; women, 46.8%). The positive rates for first-stage screening were 30.9% men and 34.6% women. The response rates for second-stage screening were 91% men and 90.5% women. Age-standardized prevalence of HCC per 1,000 subjects was 5.2 for men and 0.8 for women in Penghu Islets and 1.2 for men on Taiwan island. Among five serological biomarkers, HBsAg carrier status had the highest sensitivity (88.2%) and AFP had the second highest sensitivity (43.1%). The specificity of these markers was highest for AFP (99.0%) and lowest for HBsAg carrier status (80.3%). There were 16 new HCC cases identified after an intensive follow-up of 137 cases affected with liver cirrhos is giving an annual HCC incidence rate of 5.3%, while the rate for non-cirrhotic subjects who were positive on first-stage screening was only 0.15%. The combination of HBsAg and AFP for the first-stage screening and abdominal ultrasonography for the second-state screening seems valid for the early detection of HCC, but its cost-effectiveness remains to be elucidated by a longer follow-up study.

Age-period-cohort analysis of pulmonary tuberculosis mortality in Taiwan: 1961 to 1990

The specific aim of this study was to examine the effects of age, calendar period of death, and birth cohort in pulmonary tuberculosis (TB) mortality in Taiwan during the period 1961 to 1990. A log-linear Poisson regression model modified from the method of Osmond and Gardner was used and 79,881 deaths (58,025 males and 21,856 females) were included in the analysis. Birth cohort is the most significant predictor of pulmonary TB mortality according to the model. The earliest birth cohort from 1891 had a pulmonary TB mortality 17,327 and 6,186 times those born from 1986 for males and females, respectively. There was also a significant age effect. The youngest age group of zero to four years had a pulmonary TB mortality 7.10 and 5.87 times those for the age group of five to nine years for males and females, respectively. The oldest age group of 70 to 74 years had a risk of pulmonary TB mortality 2.89 and 1.88 times those for the five- to nine-year age groups for males and females, respectively. Parameters of the period factor showed a decreasing pulmonary TB mortality from 1961 to 1990 that was less significant than those of age or cohort. In addition to the improvement in medical measures that influenced the effect of calendar year on TB mortality, year of birth is an important determinant in the trend of TB mortality in Taiwan. The result shows that the major focus for TB mortality in Taiwan is in the age groups born between 1891 and 1921.

Age-period-cohort analysis of lung cancer mortality in Taiwan, 1966-1990

The specific aim of this study was to examine the effects of age, calender period of death, and birth cohort in lung cancer mortality in Taiwan over the period 1966-1990. A log-linear model modified from the method of Osmond and Gardner was used. Age is the most important predictor of lung cancer mortality according to the model. The oldest age group of 75-79 years old had a lung cancer mortality 185.3 and 79.2 times those for the youngest age group of 30-34 for males and females, respectively. There was also a significant cohort effect. The birth cohorts at the highest risk of lung cancer death were those born around 1931 for males and 1921 for females. A leveled off or declined trend of lung cancer mortality was observed for more recent cohorts. Parameters of the period factor showed an increasing lung cancer mortality from 1966 to 1990. In addition to the adverse effect of cigarette smoking, dietary and environmental factors should be taken into consideration in interpreting the results.

[Family influence on cancer screening participation in seven communities in Taiwan]

Cancer is the leading cause of death in Taiwan. Since there is no definitive method for cancer prevention, early detection play a major role in fighting cancer. Factors that affect people's willingness to participate cancer screening have been discussed widely except for those relating to the family. The family's role in motivation & influencing its members to participate in an invited cancer-screening program was studied in seven Taiwanese communities. 5% of participants in each area for both genders were chosen by stratified random sampling, and matched with teice-informed nonparticipants who were chosen by sex, age, and neighborhood. By means of a home visit and structured questionnaire, 729 of the 987 eligible cases were interviewed (73.9%). The main findings were that the response was higher among people with higher education, nonsmokers, and those who felt the scheduled time and place of attendance was suitable and convenient. Moreover, in the 6 variables related to family (family structure, family life cycle, cancer history in family and friends, family APGAR, family support about health problems, and family's opinion about cancer screening), the last 4 variables were found to be significantly related by chi-square analysis to the attendance. Finally, a logistic regression analysis adjusted by age, sex, education, smoking habits, time available and traffic factors was used to analyze how family factors affect attendance. The result was cancer history in family and friends (odd ratio = 2.42) and family's encouragement (odd ratio = 1.85) had a positive association.

Family factors affecting the outcome of tuberculosis treatment in Taiwan

Despite the progress of tuberculosis (TB) control, the failure of treatment mainly due to non-adherence to medical recommendations remains a major obstacle to the eradication of this disease in both industrialized and developing countries. We interviewed 397 active pulmonary TB cases (274 males and 123 females) in Taiwan and followed up their treatment outcomes. No significant differences were found between any of the groups of either sex on TB cognition scores. Positive correlations between cognition scores and compliance scores, between cognition scores and family apgar scores, and between compliance scores and family apgar scores were noted in this study. In males, the complete treatment group had a higher compliance score (mean +/- standard deviation = 13.45 +/- 2.80) and family apgar score (22.44 +/- 2.29) than the incomplete treatment group (11.61 +/- 3.21 and 14.77 +/- 3.92, respectively). In females, the complete treatment group had a higher cognition score (65.99 +/- 6.75), compliance score (13.65 +/- 2.55) and family Apgar score (22.78 +/- 2.30) than the incomplete treatment group (62.05 +/- 6.91, 11.70 +/- 3.04 and 14.84 +/- 3.80, respectively). In the logistic regression analysis, both the family Apgar score and compliance score were significantly related to the TB treatment outcomes. The subjects with a family Apgar score higher than 20 had a chance to complete treatment as high as 72-fold (95% confidence interval = 31.7-164.0) that of those with a score less than 20.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of apolipoprotein size distribution by electroimmunoblotting from non-denaturing composite gels

An exponential gradient gel with 0-35% acrylamide and 0.5% agarose was developed for electrophoresis of intact lipoproteins with subsequent electroimmunoblotting. The system resolved in a single gel lipoprotein-associated proteins of sizes from 'free' apoproteins to VLDL. Reproducibility between gels was good (coefficient of variation < 8%). Examination of the effect of mild glutaraldehyde fixation on immunodetection showed variable results (lack of effect on apos (a), AII, and AIV; inhibition of apoB; enhancement of apos AI and E). The composite gel system described here will simplify analysis of apolipoprotein distributions in both health and disease and therefore will likely be useful in future clinical applications.

Morbidity and mortality trends of pulmonary tuberculosis in Taiwan

An epidemiologic study of pulmonary tuberculosis was carried out to examine the secular trend and geographic variations of the incidence, prevalence and mortality of pulmonary tuberculosis in Taiwan. The prevalence and incidence rates declined-steadily from 1910 to 1980, but have remained unchanged during the last decade. Mortality also showed an 8.0% annual decrease from 1974 to 1986, but has remained constant without any apparent changes in recent years. Mortality for pulmonary tuberculosis is much higher in the aboriginal areas, where patients have a poor adherence to treatment and where a high prevalence of alcohol abuse exists. The mortality for pulmonary tuberculosis in Taiwan is higher than that in most developed countries, such as the U.K. and the U.S.A., but is lower than that in mainland China and the Republic of Korea.

Cerebellar units show several types of early responses to telencephalic stimulation in catfish

The responses of cerebellar units following electrical stimulation applied to the area dorsalis centralis (Dc) of the telencephalon were studied in the siluroid teleost Ictalurus nebulosus. Two kinds of units are distinguished on physiological criteria, identified as Purkinje and eurydendroid cells (the efferent neurons of the cerebellum in teleosts equivalent to cells of the deep nuclei in other vertebrates). A high proportion of both kinds of units in the corpus cerebelli are sensitive to such stimulation. Each kind of unit shows several consistent response types. Purkinje cells fire simple spikes spontaneously at the rate of 8-50 spikes/s and respond to a single shock to Dc with an initial latency of 34-64 ms. The response can be one of the following types: (1) inhibition alone, with a duration of 0.3-1.5 s; (2) initial inhibition for 0.04-0.2 s, followed by postinhibitory rebound, or (3) initial excitation followed by inhibition which may or may not be followed by a late excitation. It is suggested that the initial excitation and the initial inhibition reflect the activation of mossy fiber-granule cell-Purkinje cell circuitry and mossy fiber-granule cell-inhibitory interneuron-Purkinje cell circuitry, respectively. Indirect evidence suggests the involvement of climbing fibers, but their characteristic complex spikes are rarely seen. Changing the stimulation sites within Dc does not appear to change the response pattern but may alter the threshold intensities, latencies and amplitudes. Changing stimulation frequency has complex effects depending on the response type. Purkinje cells responding with initial excitation are located along the lateral edges and along the midline of the corpus cerebelli; units responding with initial inhibition are more often found in an intermediate zone. This suggests three sagittal bands on each side. The contralateral cerebellum has a relative excess of Purkinje cells with initially inhibitory response. Putative eurydendroid cells show either initial excitation or a pattern of inhibition, excitation, inhibition. The initial latency is longer than in Purkinje cells. The contralateral cerebellum has a relative excess of eurydendroid cells with initially excitatory response. The high proportion of units that respond to Dc stimulation, their complex dynamics, diverse response types and compartmentalization point to the importance of the cerebrocerebellar influence in teleosts. Principal differences from mammals are the much longer latencies and less differentiation according to place of stimulation in the cerebrum.

Cerebellar units show several types of long-lasting posttetanic responses to telencephalic stimulation in catfish

Extracellular spikes from Purkinje and eurydendroid cells as well as evoked field potentials were recorded from the cerebellum in a catfish following trains of 50-100 stimuli at 2-10 Hz delivered to the area dorsalis centralis (Dc) of the telencephalon. Forty out of 48 Purkinje cells tested showed some response, either an increase or a decrease in the level of ongoing spike discharge following the 10- to 25-second tetanic pulse trains. The altered level lasted for greater than 3 min. Four out of 16 eurydendroid cells showed an increase in posttrain ongoing discharge; none showed a decrease. In those Purkinje cells responding to single pulse stimulation with early excitation, that response was converted to early inhibition during the later cycles of a tetanic pulse train. When tested with posttrain stimulation, they resumed the pretrain early excitation about 100 s after the train; before that, the recovery stages are complex, neither a simple continuation of, nor a simple rebound from, the later cycles of the stimulus train. Bursting discharge of Purkinje cells is often induced or, if already present, enhanced and regularized, typically at approximately 3/s, by train stimulation of Dc. This pattern begins during the train but continues for tens of seconds after its end. The effects of a stimulus train on the mean frequency and on the pattern of ongoing discharge depend on the train parameters: intensity, duration and stimulus rate within the train; 4-5 Hz is most effective. Higher rates or repeated trains produce a more intense but shorter-lasting effect. Evoked field potentials change during a train, and posttrain test stimuli show a slow recovery, especially after longer pulse trains. The cerebrocerebellar influence in a teleost is nontrivial, widespread, differentiated and shows long-lasting posttetanic plasticity.

Responses of the optic tectum to telencephalic stimulation in catfish

In order to test physiologically for cerebrotectal connections in a fish, averaged evoked potentials and unit responses were recorded from the optic tectum following electrical stimulation applied to the telencephalon in the siluroid teleost Ictalurus nebulosus. A single shock applied to the area dorsalis centralis (Dc) of the telencephalon, and only to this area, elicits a sequence of deflections in the ipsilateral optic tectum: an initial negative peak at about 8 ms, (= N8), a larger N25 and a slow P50-N95. The configurations, depth profiles, latencies and susceptibility to repetitive stimulation, together with the known tectal anatomy, suggest that the first wave is due to the afferent fibers from the telencephalon and that N25 is due to deep tectal neurons. Telencephalic input exerts a conditioning effect on the field potentials and unit responses evoked by direct optic nerve shock. Such a shock elicits, in the contralateral tectum, small negative, optic tract axon peaks followed by a large N6, believed to be postsynaptic, and a still later P12. As a first approximation it is argued that the telencephalic input and the retinal input are activating different sets of neuronal elements in the optic tectum, since the configuration and depth profile of the telencephalic and optic nerve shock-elicited potentials are different. A conditioning Dc stimulus has a long-lasting effect on the form of the optic nerve field potential, maximally when the pallial shock precedes the optic by about 90 ms. The effect, observed by subtracting the conditioned from the unconditioned tectal response to optic nerve shock, is a difference wave with N11 and P20. The unit activity from deep tectal laminae is either activated or accelerated following Dc stimulation, while superficially located neurons are not affected. In another group of tectal units, the optic nerve shock-induced response is depressed by a preceding pallial dorsalis centralis stimulus. The evidence is compatible with the assumption of direct projections from Dc to the deep layers of the tectum, but the timing could also permit indirect pathways. In any case, the influence is not simple or identical for different tectal cell classes.

Efficient electroblotting of human very-low-density lipoproteins and low-density lipoproteins from composite gradient gels to nylon membranes

Rinsing of gradient composite acrylamide/agarose gels with 1% Triton X-100 permits the efficient electrotransfer of very-low-density and low-density lipoproteins from the gels and does not appear to interfere with subsequent capture of the lipoproteins by charged nylon membranes. Overall efficiency of the transfer/capture process can approach 95% and does not appear to be significantly affected by total lipoprotein concentrations up to 5000 mg/dl. Direct immunoquantification of transferred apolipoproteins on the membrane is feasible as well. The nylon membranes used, however, must be pretested to ensure capture efficiency.

Gradient acrylamide/agarose gels for electrophoretic separation of intact human very low density lipoproteins, intermediate density lipoproteins, lipoprotein a, and low density lipoproteins

An exponential gradient gel with 0-10% acrylamide and 0.5% agarose was developed for electrophoresis of intact high molecular weight lipoproteins. This system resolves very low density lipoproteins, intermediate density lipoproteins, lipoprotein a, and low density lipoproteins in a size-dependent fashion. The characteristic relative mobility of these species can be determined in relation to protein and colloidal gold reference materials. Electron microscopy of selected lipoprotein fractions confirmed that relative mobility was related to apparent lipoprotein diameter. The composite gel medium can be used with prestained lipoproteins and permits immunoelectroblotting for qualitative analysis of apolipoprotein constituents.

Identification of a mouse monoclonal antibody, LHLP-1, specific for human Lp(a)

Heretofore, immunologic reagents used to define and quantify human Lp(a) have been polyclonal in origin and therefore heterogeneous in antigenic specificity. We report here the isolation of a mouse monoclonal antibody, LHLP-1, monospecific for Lp(a). The antigen reactive with LHLP-1 was expressed in both lipoprotein Lp(a) as well as apolipoprotein Lp(a) delipidated by SDS treatment; however, disulfide reduction of apolipoprotein Lp(a) inhibited LHLP-1 reactivity. The antigen reactive with LHLP-1 on Lp(a), therefore, appears not to require lipid for expression of its conformationally dependent (disulfide-inhibitable) epitope. Antigen reactivity was virtually absent in the apoB and other proteins contained in very low density, low density, and high density lipoprotein particles. Immunologic quantification of Lp(a) in individual serum samples with a rabbit reference antiserum or LHLP-1 showed good correlation. We conclude that the monoclonal antibody LHLP-1 identifies an antigen unique to Lp(a) and that this antibody may therefore be useful in the further characterization and measurement of human Lp(a).

Sensory representation in the cerebellum of the catfish

Sensory representation in the catfish cerebellum was studied with physiological stimuli, with electric shocks applied to peripheral nerves and with electric shocks to central structures of the brain. Evoked field potentials and unit responses were recorded in different places in the cerebellum. In the catfish, different sensory modalities are represented by discrete, only partly overlapping areas of the cerebellum. Most units are unimodal by present criteria; only in the valvula a fraction of the units are responsive to two or more modalities. Visual and somatosensory areas are the largest and they occupy the bulk of the corpus cerebelli and the valvula. In the corpus, most of the visual units are near the midline and in the dorsal tier while the somatosensory units are more lateral and ventral. Mechanical lateral line input is represented in the eminentia granularis and the valvula. Acoustic units are found in the valvula. Electroreceptive units are recorded from the lateral lobus caudalis, and to a lesser degree, from the eminentia granularis and valvula. Sinusoidal tilting and vibration units are in the lobus caudalis pars medialis. Receptive fields of units, regardless of modality, are generally large and diffuse. Some visual units respond best to moving objects. Topographical organization of receptive fields only exists among the somatosensory units. Besides these findings of modality segregation, the features of interest for comparative neurology are the following. Most units are identifiable as Purkinje cells with a characteristic mossy fiber-granular cell pattern, and but in contrast to most experience with mammals, in response to direct brain or nerve stimulations, the simple spikes have different dynamic responses for different modalities. Some are first excited, then inhibited, others vice versa. Some units are not responsive to any sensory input we delivered. Some units not meeting the criteria for Purkinje cells meet several criteria for eurydendroid cells; they give large spikes and are influenced by sensory stimuli after relative long latencies. Complex spikes, however, were only consistently observed in some of the visual units.

Response of cerebellum to stimulation of telencephalon in the catfish (Ictalurus nebulosus)

In the siluroid teleost Ictalurus nebulosus, averaged evoked potentials and unit responses were recorded from various parts of the cerebellum following electrical stimulation applied to the telencephalon. Responses are most readily evoked in the cerebellum when area dorsalis pars centralis (Dc), a group of scattered large cells in the middle of the telencephalon, is stimulated. The configuration of the evoked field potentials differs according to the rate of stimulation. At a relatively low repetition rate, 0.5/s or lower, the response takes the shape of a positive wave, Pmol2, peaking at about 58 ms in the molecular layer. In the granular layer, the response is primarily a negative wave, Ngr1, followed by a slow positive deflection, Pgr3, with peak latencies of 52 and 130 ms, respectively. Ngr1 appears to be the result of summed mossy fiber-granule cell synaptic activations, with Pmol2 its concomitant passive source. No neuronal basis can be proposed for Pgr3. At higher rates of stimulation (greater than 2/S), the response to each shock is of longer latency and more complex. The stabilized waveform (i.e., after 5-9 cycles) is dominated by a surface-negative wave, Nmol, peaking at about 80 ms. The negative wave disappears at about 300 micron below the surface (slightly above the level where Purkinje cells are located) where it is replaced by a positive and negative sequence, P-Npur, peaking at about 80 and 160 ms, respectively. Both responses are bilaterally distributed but the ipsilateral responses are usually larger in amplitude and shorter in latency. Rostrocaudally, a latency gradient with longer rostral latencies is also found in both responses. To facilitate further comparative studies, the changes of peak latency and amplitude with stimulus strength of these two patterns of response were examined. Other dynamic characteristics of these two patterns of response were also examined and compared by stimulating with pairs and short trains of electric shocks. In discussing the functional implications of these findings, this telencephalocerebellar pathway appears to be a striocerebellar pathway.

Immunochemical studies on Tn erythrocyte glycoprotein

Glycoproteins were extracted from membranes of erythrocytes that displayed Tn polyagglutination and were compared chemically and immunologically with glycoproteins of group O, MN cells. Tn glycoprotein had lower than normal NANA : protein and sugar : protein ratios, as revealed by direct analysis and polyacrylamide gel electrophoresis, and displayed slower immunoelectrophoretic mobility than glycoproteins of group O, MN cells. Agglutination of Tn cells by Salvia sclarea lectin was inhibited by Tn glycoprotein but not by O, MN glycoprotein. Tn and MN glycoproteins were equally potent inhibitors of influenza virus HA. Our findings indicate than Tn-specific determinants are part of the glycophorin molecule.

Competitive inhibition by soluble erythrocyte glycoproteins of penetration by Plasmodium falciparum

Glycophorin, the major sialoglycoprotein of the erythrocyte membrane, was extracted from human erythrocyte ghosts by the lithium diiodosalicylate phenol (LIS) or chloroform-methanol (CM) methods. The products (LISgp and CMgp) were examined for their capacity to inhibit invasion of erythrocytes by Plasmodium falciparum in vitro. In the presence of either glycoprotein, parasitemia was significantly less than in control cultures, indicating competitive inhibition of attachment. Desialylation resulted in only partial loss of this inhibitory potency. Neither crystalline NANA nor the dialyzates of either hydrolyzed glycoprotein had any inhibitory effect. We conclude that the receptor for merozoites of P. falciparum probably resides in the protein portion of glycophorin, in which NANA plays a secondary role, possibly related to hydration of the cell surface. The parasite itself contains no detectable neuraminidase activity.

Immune electron microscopy of cross-reactions between Mycoplasma pneumoniae and human erythrocytes

Respiratory infection with Mycoplasma pneumoniae evokes immunoglobulin M autoantibody which agglutinates human erythrocytes at 4 degrees C (cold agglutinin) and is specific for I antigen. Cross-reactions between surface antigens of M. pneumoniae and human erythrocytes, previously examined by serological analysis, were examined by transmission and scanning electron microscopy. Ferritin-labeled human antimycoplasmal and rabbit antisera to erythrocyte membrane components reacted with antigens on the surface of both M. pneumoniae and erythrocytes. Adsorption of human erythrocytes to M. pneumoniae was blocked by the same antisera without ferritin label. It is proposed that the cross-reactive specificity lies in peripheral areas of the mycoplasmal cell, probably in a surface carbohydrate which has antigenic identity with erythrocyte glycoprotein.

Cold hemagglutinin cross-reactivity with Mycoplasma pneumoniae

Convalescent sera from proven cases of infection with Mycoplasma pneumoniae, and rabbit antisera to M. pneumoniae and to human erythrocyte glycoprotein contained cold hemagglutinins which were reactive only for human erythrocytes. Only the human serum cold agglutinins were inhibited by soluble integral glycoproteins derived from human erythrocyte ghosts by treatment with chloroform-methanol. Rabbit antiserum to chloroform-methanol glycoprotein, as well as to M. pneumoniae, fixed complement with either M. pneumoniae or chloroform-methanol glycoprotein antigens. The findings support the hypothesis that the cold agglutinins elicited by M. pneumoniae infection represent a cross-reaction between determinants common to erythrocyte glycoprotein containing I antigen and the membrane of M. pneumoniae.

Removal of unbound sodium dodecyl sulfate (SDS) from proteins in solution by electrophoresis through triton x-100-agarose

Residual sodium dodecyl sulfate (SDS) introduces artifacts into immuno- and counterimmunoelectrophoretic analysis of proteins which have been eluted from preparative SDS-polyacrylamide gels. Unbound SDS can be removed by electrophoretic passage of eluted solutions through a barrier of Triton X-100 in agarose in which the anionic and non-ionic detergents interact to form micelles.