Specific expression of the LIM/homeodomain protein Lim-1 in horizontal cells during retinogenesis

The LIM/homeodomain transcription factor Lim-1 has been shown to play an essential role in early embryonic patterning during vertebrate development. Here we report the spatial and temporal expression patterns of Lim-1 during retinal development as detected by immunohistochemistry using a specific anti-Lim-1 antibody. By double-immunostaining, we have demonstrated for the first time that Lim-1 is exclusively expressed within the horizontal cell type in the adult retina. In the developing mouse retina, Lim-1 commences its expression in migratory horizontal cell precursors streaming toward the future horizontal cell layer in the ventricular zone. Moreover, its expression during retinogenesis is spatially and temporally coincident with that of the calcium-binding protein calbindin D-28k in horizontal cells. These data together suggest a possible role for Lim-1 in terminal differentiation and maintenance of horizontal cells, and that Lim-1 can serve as a specific molecular marker for the study of horizontal cell specification.

Dichotomic effects of IFN-gamma on the development of systemic lupus erythematosus-like syndrome in MRL-lpr / lpr mice

Systemic lupus erythematosus (SLE)-prone female MRL-lpr / lpr (MRL-lpr) mice were treated with mouse or rat IFN-gamma under different experimental conditions, both prophylactically in 6- to 8 week-old animals and therapeutically in 12- to 18-week-old SLE-affected mice. It was found that IFN-gamma heterogeneously modulated the course of the disease in MRL-lpr mice. When administered prophylactically, IFN-gamma favorably modulated the histological, serological and clinical signs of the disease. Relative to untreated or PBS-treated control animals, the MRL-lpr mice which received IFN gamma were virtually free of inflammatory infiltration of the kidneys and the lungs, had lower levels of azotemia with reduction of both circulating IgG1, IgG2a and IgG3 and anti-double strand (ds) and single strand (ss) DNA antibodies, milder skin vasculitis, significantly reduced enlargement of their lymph nodes and lower weight of the spleens. IFN-gamma also lowered the rate of mortality of MRL-lpr mice. In contrast to these findings, therapeutically administered IFN-gamma worsened the course of the disease in MRL-lpr mice, which exhibited increased proteinuria, higher levels of IgG2a and IgG3 and anti-ds and -ss DNA antibodies, more aggressive nephritis and died at an earlier age than PBS-treated control mice. The dichotomic effect of IFN-gamma on disease manifestation in MRL-lpr mice offers new insights into the complex role of this cytokine in the regulation of systemic autoimmunity such as SLE.

Long-chain polyunsaturated fatty acids in human milk and brain growth during early infancy

Long-chain polyunsaturated fatty acids are essential for growth and development, and their crucial role in the development of the central nervous system and in retinal function has been the subject of many studies. As the balance between n-6 and n-3 fatty acids has to be optimal, their concentrations in the milk given to infants who are exclusively breastfed is of major importance. In this study, the composition of fatty acids in mothers' milk and the growth rate of the infant brain were analysed. Nineteen mother-term infant pairs from Stockholm, Sweden, were studied from birth to 1 mo and 3 mo of age, during which time the infants were breastfed exclusively. The dietary intake of the mothers was calculated and found to concur with the recommended daily dietary allowances of Swedish lactating women as regards energy, protein, fat and carbohydrates. The amounts of linoleic acid and alpha-linolenic acid in the diet were similar to those reported for European and North American women. The ratio between arachidonic acid (AA) and docosahexaenoic acid (DHA) in the milk from Swedish mothers is approximately the same as in the brain of infants, and was found to be positively correlated with the rate of gain of the occipito-frontal head circumference and of the calculated brain weight at 1 mo (p < 0.01) and 3 mo (p < 0.01) of age, respectively. However, further studies are needed to establish the exact requirements of AA and DHA for optimal growth and development during early infancy in exclusively breastfed infants.

Reproductive and hormonal risk factors for thyroid cancer in Los Angeles County females

We conducted an individually matched case-control study (292 pairs) of female thyroid cancer patients to examine the role of reproductive history and exogenous hormones in this disease. Radiation treatment to the head or neck [28 cases and 2 controls exposed; odds ratio (OR), 14.0; 95% confidence interval (CI), 3.5-121.3] and certain benign thyroid diseases (including adolescent thyroid enlargement, goiter, and nodules or tumors) were strongly associated with thyroid cancer. Irregular menstruation increased risk (OR, 1.8; 95% CI, 0.9-3.7). Age at menarche and pregnancy history were not related to disease. Women with natural menopause and hysterectomized women without oophorectomy had no increase in risk, but disease risk was elevated in women with bilateral oophorectomy (OR, 6.5; 95% CI, 1.1-38.1). In general, use of oral contraceptives and other exogenous estrogens was not associated with thyroid cancer. However, risk increased with number of pregnancies in women using lactation suppressants (P = 0.03) and decreased with duration of breastfeeding (P = 0.04). These data provide only limited support for the hypothesis that reproductive and hormonal exposures are responsible for the marked excess of thyroid cancer risk in adult females.

Concanavalin A-induced hepatitis in mice is prevented by interleukin (IL)-10 and exacerbated by endogenous IL-10 deficiency

One single intra-venous (i.v.) injection of Concanavalin A (Con A) into mice provokes a cell-mediated immunoinflammatory hepatitis. We have presently evaluated the immunopharmacological effects of exogenous interleukin (IL)-10 and the role of endogenous IL-10 in this model by using exogenous IL-10, anti-IL-10 monoclonal antibody (mAb) and mice with disrupted IL-10 gene (IL-10 KO mice). Whilst exogenous IL-10 administered in a prophylactic (1 h prior to Con A) and even "early" therapeutic fashion (30 min after Con A) reduced the elevation of transaminase activities in plasma in a dose-dependent manner, observed in control mice, these biochemical markers of liver injury were significantly increased both in IL-10 KO mice as well as in those receiving anti-IL-10 mAb. Interestingly, doses of Con A lower than 20 mg/kg that were only capable of inducing slight serological signs of hepatitis in mice, exerted marked hepatitic effects when administered to either anti-IL-10 mAb-treated mice or to IL-10 KO mice. The disease modulating effects of exogenous IL-10 and either genetical or pharmacologically-induced IL-10 deficiency were associated with profound and opposite modifications of the Con A-induced increase in the circulating levels of IFN-gamma and TNF-alpha. Relative to control animals, the blood levels of these cytokines were diminished in IL-10-treated mice and augmented in both IL-10 KO mice and anti-IL-10 mAb-treated mice. These results prove the physiological antiinflammatory role of endogenous IL-10 in Con A induced hepatitis and the beneficial effects of IL-10 treatment to prevent this condition.

Failure of exogenously administered interferon-gamma or blockage of endogenous interleukin-4 with specific inhibitors to augment the incidence of autoimmune diabetes in male NOD mice

Interferon (IFN)-gamma and interleukin (IL)-4 are prototypic type 1 and type 2 cytokines which are known to play pathogenetic and protective roles, respectively, in NOD mouse IDDM. The capacity of male NOD mice to produce more IL-4 and less IFN-gamma within the insulitic lesions than females has been suggested to contribute to their lower incidence of diabetes. In this study we have tested the effects of prolonged prophylactic treatment of male NOD mice with rat IFN-gamma, mouse IFN-gamma, anti-IL-4 monoclonal antibody (mAb) and recombinant murine soluble IL-4 receptor (smIL-4R) on the diabetogenic events leading to insulitis and diabetes. None of these treatments influenced spontaneous and/or cyclophosphamide-induced autoimmune diabetogenesis in male NOD mice. Control mice exhibited comparable histological signs of insulitis and incidence of diabetes to those treated with either mouse/rat IFN-gamma or specific IL-4 inhibitors. On the contrary, both clinical and histological signs of diabetes were suppressed by prophylactic treatment with anti-IFN-gamma mAb. These findings indicate that the autoimmune diathesis of male NOD mice towards IDDM cannot be augmented by manipulation of endogenous IFN-gamma or IL-4.

Relation between polyunsaturated fatty acids and growth

Although it was discovered in the late 1920s that polyunsaturated fatty acids (PUFA) are essential for proper growth and development in animals, their nutritional importance in humans has not attained general interest until the 1990s, when the role for growth and development has been extensively studied in both humans and animals. It is now known that PUFA regulate various developmental and physiological processes, and that they are of essential importance for early human growth and development. Thus, linoleic acid is the precursor of arachidonic acid, from which hormone-like compounds, such as prostaglandins and leukotrienes, are formed, whereas alpha linolenic acid is the precursor of docosahexaenoic acid, which is an essential compound in cell membranes and occurs in particularly high concentration in the photoreceptors. In this paper the role of PUFA for human growth will be reviewed.

Prophylaxis with the novel immunomodulator pidotimod reduces the frequency and severity of upper respiratory tract infections in children with Down's syndrome

Down's syndrome (DS) is associated with several defects of both specific and non-specific immunity which may explain the enhanced susceptibility of DS subjects to viral and bacterial infections. In this study we have evaluated the effects of the new synthetic immunomodulator pidotimod in recurrent infections of the upper respiratory tract in a group of children with DS. It was an open trial vs untreated control, the pidotimod-treated group consisted of 14 subjects and the control group of 12. Pidotimod was administered at the dose of one 400 mg oral bottle/day for 90 days. There was a significant reduction in the frequency, severity and duration of infectious episodes in the pidotimod-treated group vs the untreated control group. The beneficial effects of pidotimod were also confirmed by a series of recordings made over the 90-day treatment period which showed a significant reduction in the number of days of fever, severity of the signs and symptoms of the acute episodes and use of antibiotics and antipyretic drugs. Pidotimod was well tolerated and no clinical, hematological or biochemical side-effects were noted.

Fluorophotometry in patients with human immunodeficiency virus with and without cytomegalovirus retinitis

OBJECTIVE

To study the aqueous humor dynamics in subjects with human immunodeficiency virus (HIV) with and without cytomegalovirus (CMV) retinitis.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS

Fourteen HIV-positive subjects (27 eyes, 19 with CMV retinitis and 8 without CMV retinitis), and a control group of 9 HIV-negative subjects (17 eyes).

TESTING

Fluorophotometry.

MAIN OUTCOME MEASURES

Aqueous flow rates as measured by fluorophotometry and intraocular pressure (IOP).

RESULTS

Analysis of variance of the mean corrected aqueous flow rate revealed that both HIV-positive groups had significantly lower aqueous flow rates than did the control group (P < 0.03). No difference in mean aqueous flow rates was found between the HIV-positive eyes with or without CMV retinitis. Comparison of mean IOP revealed that HIV-positive eyes with CMV retinitis had significantly lower IOP than did the HIV-positive eyes without CMV retinitis (P = 0.03) and HIV-negative subjects (P = 0.002). There was no correlation between aqueous flow rate and IOP in HIV-positive subjects (P > 0.5).

CONCLUSION

The lack of correlation between the aqueous flow rate and IOP suggests that there may be some disassociation between these parameters in HIV-positive patients. Further studies are needed to better understand the mechanism of aqueous formation and in the management of disorders affecting IOP in this population.

Prevention by rolipram of concanavalin A-induced T-cell-dependent hepatitis in mice

Rolipram is a type IV phosphodiesterase inhibitor endowed with powerful immunomodulatory properties. In this study, we evaluated the effects of this drug on the development of the T-cell-mediated hepatitis inducible in mice by concanavalin A. The results indicated that prophylactic treatment with either 5 or 10 mg/kg rolipram injected intraperitoneally 24 h and 1 h prior to intravenous (i.v.) challenge with 20 mg/kg concanavalin A successfully ameliorated serological and histological signs of liver damage, so that the treated mice showed lower transaminase levels in the plasma and milder mononuclear cell infiltration of the liver as compared to vehicle-treated controls. Moreover, this effect was associated with profound modifications of circulating levels of cytokines released after concanavalin A injection, with the blood levels of interferon-gamma and tumor necrosis factor-alpha being significantly lower and those of interleukin-10 higher than those of the control mice. In particular, the increased blood levels of interleukin-10 might play an important role in the anti-hepatitic effects of rolipram as coadministering this compound with anti-interleukin-10 monoclonal antibody significantly reduced its anti-inflammatory action. These results suggest that rolipram may be useful in the clinical setting for the treatment of cell-mediated immunoinflammatory diseases such as immunoinflammatory hepatitis.

Composition of long chain polyunsaturated fatty acids in human milk and growth of young infants in rural areas of northern China

The main source of fat in the diet in rural areas of northern China is soybean oil, therefore the pattern of essential fatty acids in human milk may be assumed to differ from that in milk from women in Western countries and to be similar to that of vegans. The concentrations of long chain polyunsaturated fatty acids in human milk and information on diet were analysed for 41 lactating women in rural areas of north China, and the growth of their infants was measured. The subjects were divided into two groups (group I, 1 mo postpartum; group II, 3 mo postpartum). The dietary intake of the mothers was high in carbohydrate and low in fat, protein and energy. The concentrations of linoleic acid (LA) and alpha-linolenic acid (LNA) were high. The ratio of LA to LNA, (21.6), was higher than has been reported from other countries. The concentration of docosa-hexaenoic acid (DHA) was low and the ratio of arachidonic acid (AA) to DHA was much higher (2.8) than recommended and similar to that found in vegans. The concentrations of AA and DHA in the milk correlated positively with the infants' weight gain at the third month (p<0.05) and of DHA with length gain at the first and third months (p<0.01). Since the concentration of AA and, particularly, DHA in the milk declined during lactation, DHA deficiency may appear after 3-4 mo of age in breastfed Chinese rural infants. Further studies of Chinese rural mother-infant pairs are necessary to prove whether supplementation with suitable sources of AA and DHA, such as fish oil, should be recommended as lactation is lengthened to ensure optimal infant growth and development.

[Determination of total Ca in the lung tissue of rats by FAAS]

Determination of total Ca in the Lung Tissue of Rats by FAAS was described, with a mixed microemulsion consisting of sodium dodecyl sulfate, N-dodecyl, N-dimethyl benzol ammonium bromide and nonyl phenol polyethyeneoxy ether. Comparing the result of the microemulsion FAAS with that of solution FAAS showed that the former was better than the latter in sensitivity, precision, selectivity and linearity of the calibration curve, with a detection limit of 1.92 microg x cm(-3), relative standard deviation of 1.92% (n = 10) and linear regressive coefficient of 0.9998 of the calibration curve over 0-20 microg x cm(-3) calcium. The method was applied to determine calcium amount in the lung tissue of rats, and the results were in accordance with those odtained by the conventional solution FAAS, in which a sample was reduced to ashes at a high temperature.

Requirement for Brn-3c in maturation and survival, but not in fate determination of inner ear hair cells

Mutations in the POU domain gene Brn-3c causes hearing impairment in both the human and mouse as a result of inner ear hair cell loss. We show here that during murine embryogenesis, Brn-3c is expressed in postmitotic cells committed to hair cell phenotype but not in mitotic progenitors in the inner ear sensory epithelium. In developing auditory and vestibular sensory epithelia of Brn-3c−/− mice, hair cells are found to be generated and undergo initial differentiation as indicated by their morphology, laminar position and expression of hair cell markers, including myosins VI and VIIa, calretinin and parvalbumin. However, a small number of hair cells are anomalously retained in the supporting cell layer in the vestibular sensory epithelia. Furthermore, the initially differentiated hair cells fail to form stereociliary bundles and degenerate by apoptosis in the Brn-3c−/− mice. These data indicate a crucial role for Brn-3c in maturation, survival and migration of hair cells, but not in proliferation or commitment of hair cell progenitors.

Requirement for Brn-3b in early differentiation of postmitotic retinal ganglion cell precursors

The Brn-3 subfamily of POU domain transcription factors consists of Brn-3a, -3b, and -3c, which are important regulators for sensorineural development. Despite the expression of all three factors in retinal ganglion cells, earlier studies have shown that Brn-3b is the only one among the three Brn-3 genes that is essential for development of approximately 70% of ganglion cells in the murine retina. I report here that Brn-3b displays a spatiotemporal expression pattern characteristic of the dynamic profile of ganglion cell genesis during murine retinal development. Moreover, it is initially turned on in postmitotic ganglion cell precursors 2 days before the onset of Brn-3a and -3c expression in differentiated ganglion cells. During the entire period of retinal ganglion cell genesis, the postmitotic ganglion cell precursors that would normally become Brn-3b+ cells fail to properly differentiate in Brn-3b-/- mice, as evidenced by a twofold reduction in the optic nerve size and diminished expression of several ganglion cell markers. The undifferentiated ganglion cell precursors appear to be degenerated by apoptosis within the ganglion cell layer during the perinatal and early postnatal period. I propose that retinal ganglion cells develop following two separate differentiation pathways--Brn-3b dependent and Brn-3b independent. In the Brn-3b-dependent mechanism, Brn-3b may be required to initiate a particular differentiation program for a large set of postmitotic ganglion precursors to properly differentiate into the 70%, Brn-3b-dependent retinal ganglion cells.

[A study of Nexin 1 of skin and hair follicle during postnatal development period of rat]

OBJECTIVE

The changes of Nexin 1 mRNA of skin hair follicles of postnatal rats were investigated on tissue sections in this paper in order to get more information about the possible functions of Nexin 1 in regulating of hair growth and cycle.

METHODS

The distribution and quantity of Nexin 1 mRNA on the paraffin sections of skin and hair follicle of Wistar rats, aged from postnatal 1 day to 61 day, were investigated by radiolabel In Situ Hybridization technique.

RESULTS

When the rats were 4 days old, the signals of Nexin 1 mRNA in the follicular papillary cells were observed. The signals of Nexin 1 mRNA showed a regular changes in the hair cycles: the signal of Nexin 1 mRNA appeared in the early stage of anagen phase and became higher level gradually, the peak was in the middle-late(IV) stage of anagen and decreased in later anagen but it totally disappeared when the follicles entered into catagen and telegen phases of hair cycles. Nexin 1 message was only accumulated in follicular papillary cells but no signal of Nexin 1 mRNA was detected in any other skin and hair follicular cells, including dermal fibroblasts, mast cells, adipocytes, endothelial or muscle cells, keratinocytes of skin and in different layers of hair follicle were showing also negative.

CONCLUSIONS

These results suggested a possible role of Nexin 1 which was a potent serine-protease inhibitor and have been shown in many organs to play important roles in regulating cellular growth and differentiation in regulating hair follicular growth.

[Will chronic nonproductive cough with bronchial hyperresponsiveness be cough variant asthma?]

OBJECTIVE

The clinical characteristics of the patients suffered from chronic nonproductive cough with bronchial hyperresponsiveness were analyzed, so as to evaluate the value of measurement of bronchial responsiveness in diagnosis of cough variant asthma (CVA).

METHOD

124 patients with chronic nonproductive cough were divided into two groups after the measurement of bronchial responsiveness: cough bronchial hyperresponsiveness positive group (CBH-P, n = 35) and cough bronchial hyperresponsiveness negative group (CBH-N, n = 33). Routine pulmonary function, positive rate of antigen-skin pitting lest, count of blood eosinophil cells, level of blood IgE, positive rate of prednisone test and the number of development of classical asthma in two-year following up were studied.

RESULT

The percentage of FEV1.0 in group CBH-P was significantly lower than in group CBH-N, but antigen-skin pitting test, count of blood eosinophil cells, prednisone test and the number of development of classic asthma in two-year following up were all higher than in the latter group. In group CBH-P, there was no significant difference in positive rate of antigen-skin pitting test, routine pulmonary function, reacting threshold(Dmin) and wheezing threshold (DCW/Dmin) between the patients who developed classic asthma and those who did not.

CONCLUSION

The measurement of bronchial responsiveness is important for the diagnosis of CVA, but it is not the only diagnostic criteria and should be combined with other clinical data.

Relationship between fatty acid compositions and taurine concentration in breast milk from Chinese rural mothers

Long chain ω3 and ω6 fatty acids and taurine have been suggested to have structural and/or functional roles in the brain. In this study the levels of fatty acids and taurine in breast milk and their correlations were investigated in 46 lactating women from an area 100 km north-east of Beijing, China. The subjects consisted of two groups: group 1 was 22-47 days postpartum and group 2 was 75-106 days postpartum. Fatty acids and taurine in breast milk were measured by gas-liquid chromatography and high-performance liquid chromatography, respectively. The relative compositions of long chain ω6 and ω3 fatty acids decreased significantly (20:3 ω6, 20:4 ω6, 22:4 ω6, 22:5 ω6 and 22:6 ω3; all P < 0.01) in the course of lactation, while long chain saturated (20:0, 22:0) and monounsaturated (20:1, 22:1) fatty acids tended to increase. The ratio of ω6/ω3 fatty acids in breast milk fat appeared to be higher (12.3 ± 4.3 for group 1, and 16.5 ± 7.4 for group 2) than the desired range of 4-10. Breast milk taurine concentrations from Chinese rural mothers were 186 ± 48 nmol/mL and 157 ± 65 nmol/mL for groups 1 and 2, respectively. A significantly inverse relationship was observed between breast milk taurine concentration and the ratio of arachidonic acid ω6 to docosahexaenoic acid ω3 (r = -0.323, P = 0.028). Further studies on the physiological function(s) of taurine as an antioxidant and as a neurotransmitter are worth pursuing in relation to the balance of long chain ω6 and ω3 fatty acids, especially as regards its role in retina and brain development.

[A longitudinal study on deterioration of physical function in people aged over 55 in Beijing]

The objective of this study is to explore the index of physical performance test in detecting physical functional status among elderly people. Physical performance test, recommended by Yale University in EPESE was used in the study. A total number of 1,986 people aged 55 and over in urban and rural area of Beijing was studied in a three-year longitutinal observation. Among 1,986 cases studied in 1992, 168 died between 1992-1994. The mortality rate increased along with the degree of functional disablement, lowest in non-disabled (3.4%), followed by mild ones (5.2%), moderate (10.5%) and highest in severely disabled (18.4%). It is shown that performance test can be used as a tool in observing and detecting risk groups in the progress of functional disability It's an important index describing the decline of health status.

Essential role of POU-domain factor Brn-3c in auditory and vestibular hair cell development

The Brn-3 subfamily of POU-domain transcription factor genes consists of three highly homologous members-Brn-3a, Brn-3b, and Brn-3c-that are expressed in sensory neurons and in a small number of brainstem nuclei. This paper describes the role of Brn-3c in auditory and vestibular system development. In the inner ear, the Brn-3c protein is found only in auditory and vestibular hair cells, and the Brn-3a and Brn-3b proteins are found only in subsets of spiral and vestibular ganglion neurons. Mice carrying a targeted deletion of the Brn-3c gene are deaf and have impaired balance. These defects reflect a complete loss of auditory and vestibular hair cells during the late embryonic and early postnatal period and a secondary loss of spiral and vestibular ganglion neurons. Together with earlier work demonstrating a loss of trigeminal ganglion neurons and retinal ganglion cells in mice carrying targeted disruptions in the Brn-3a and Brn-3b genes, respectively, the Brn-3c phenotype reported here demonstrates that each of the Brn-3 genes plays distinctive roles in the somatosensory, visual, and auditory/vestibular systems.

Targeted deletion of the mouse POU domain gene Brn-3a causes selective loss of neurons in the brainstem and trigeminal ganglion, uncoordinated limb movement, and impaired suckling

The Brn-3 subfamily of POU domain genes are expressed in sensory neurons and in select brainstem nuclei. Earlier work has shown that targeted deletion of the Brn-3b and Brn-3c genes produce, respectively, defects in the retina and in the inner ear. We show herein that targeted deletion of the Brn-3a gene results in defective suckling and in uncoordinated limb and trunk movements, leading to early postnatal death. Brn-3a (-/-) mice show a loss of neurons in the trigeminal ganglia, the medial habenula, the red nucleus, and the caudal region of the inferior olivary nucleus but not in the retina and dorsal root ganglia. In the trigeminal and dorsal root ganglia, but not in the retina, there is a marked decrease in the frequency of neurons expressing Brn-3b and Brn-3c, suggesting that Brn-3a positively regulates Brn-3b and Brn-3c expression in somatosensory neurons. Thus, Brn-3a exerts its major developmental effects in somatosensory neurons and in brainstem nuclei involved in motor control. The pheno-types of Brn-3a, Brn-3b, and Brn-3c mutant mice indicate that individual Brn-3 genes have evolved to control development in the auditory, visual, or somatosensory systems and that despite differences between these systems in transduction mechanisms, sensory organ structures, and central information processing, there may be fundamental homologies in the genetic regulatory events that control their development.

Similarities and differences among inner retinal neurons revealed by the expression of reporter transgenes controlled by Brn-3a, Brn-3b, and Brn-3c promotor sequences

Brn-3a, Brn-3b, and Brn-3c are highly homologous POU-domain transcription factors that are expressed in subsets of retinal ganglion cells. From each of the mouse Brn-3 genes, a DNA segment ranging in size from 4.6 to 13.4 kb and located immediately upstream of the start site of translation was joined to a human placental alkaline phosphatase (AP) reporter cDNA. Following the introduction of each construct into the mouse germline, a total of 19 transgenic lines were obtained, of which 16 expressed the AP reporter in the retina. Unexpectedly, at least 14 of the 16 expressing lines showed AP activity in subsets of amacrine cells, and these subsets typically differed among mouse lines injected with the same construct. Transgene expression was also found in ganglion cells in four lines and bipolar cells in seven lines. In all cases AP activity was confined to cells in the inner nuclear layer and the ganglion cell layer. The expression of Brn-3 transgenes in multiple cell types in the inner retina is reminiscent of earlier experiments in which visual pigment transgenes were found to be expressed in multiple cell types in the outer retina. Taken together, these observations suggest that anatomically and/or functionally related retinal neurons contain partially overlapping transcriptional regulatory specificities.

POU domain factor Brn-3b is required for the development of a large set of retinal ganglion cells

The three members of the Brn-3 family of POU domain transcription factors are found in highly restricted sets of central nervous system neurons. Within the retina, these factors are present only within subsets of ganglion cells. We show here that in the developing mouse retina, Brn-3b protein is first observed in presumptive ganglion cell precursors as they begin to migrate from the zone of dividing neuroblasts to the future ganglion cell layer, and that targeted disruption of the Brn-3b gene leads in the homozygous state to a selective loss of 70% of retinal ganglion cells. In Brn-3b (-/-) mice other neurons within the retina and brain are minimally or not at all affected. These experiments indicate that Brn-3b plays an essential role in the development of specific ganglion cell types.

Molecular biology of retinal ganglion cells

Retinal ganglion cells are the output neurons that encode and transmit information from the eye to the brain. Their diverse physiologic and anatomic properties have been intensively studied and appear to account well for a number of psychophysical phenomena such as lateral inhibition and chromatic opponency. In this paper, we summarize our current view of retinal ganglion cell properties and pose a number of questions regarding underlying molecular mechanisms. As an example of one approach to understanding molecular mechanisms, we describe recent work on several POU domain transcription factors that are expressed in subsets of retinal ganglion cells and that appear to be involved in ganglion cell development.

The Brn-3 family of POU-domain factors: primary structure, binding specificity, and expression in subsets of retinal ganglion cells and somatosensory neurons

A search for POU domain sequences expressed in the human retina has led to the identification of three closely related genes: Brn-3a, Brn-3b, and Brn-3c. The structure and expression pattern of Brn-3b was reported earlier (Xiang et al., 1993); we report here the structures and expression patterns of Brn-3a and Brn-3c. Antibodies specific for each Brn-3 protein were generated and shown to label only ganglion cells in a variety of vertebrate retinas. A complex pattern of strongly and weakly immunolabeled ganglion cells was observed in mouse, cat, and monkey retinae. In mouse and cat retinae, Brn-3a and Brn-3b proteins are found in a large fraction of ganglion cells, whereas Brn-3c is present in fewer ganglion cells. In the cat retina, anti-Brn-3a immunoreactivity was strong in the small ganglion cells (gamma cells) and weak in the remaining ganglion cells (alpha and beta cells); anti-Brn-3b immunoreactivity was present in all ganglion cells; and anti-Brn3c immunoreactivity was confined to the small ganglion cells. Immunolabeling of macaque retinae following retrograde labeling from the lateral geniculate nucleus revealed strong anti-Brn-3a immunoreactivity in a minority of retrogradely labeled P-type ganglion cells, and weak Brn-3a immunoreactivity in all of the remaining P- and M-type ganglion cells. In the same retinae, strong anti-Brn-3b immunoreactivity was seen in nearly all P-type ganglion cells and weak immunoreactivity in nearly all M-type ganglion cells. Each of the Brn-3-specific antibodies also labeled subsets of neurons in the dorsal root and trigeminal ganglia, suggesting that primary somatosensory neurons and retinal ganglion cells share genetic regulatory hierarchies. In vitro selection of an optimal DNA binding site using the Brn-3b POU domain has revealed a consensus [(A/G)CTCATTAA(T/C)] that is recognized by each of the Brn-3 POU domains and is distinct from binding sites previously described for other POU domain proteins.

Enzyme-enzyme interaction in the chloroplast: glyceraldehyde-3-phosphate dehydrogenase, triose phosphate isomerase and aldolase

Apparent physical interaction between pea chloroplast (Pisum sativum L.) glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.13) and aldolase (EC 4.1.2.13) is seen in phase-partitioning, fluorescent-anisotropy and isoelectric-focusing experiments. Similarly, results obtained in phase-partitioning and isoelectric-focusing experiments indicate physical interaction between aldolase and triose-phosphate isomerase (EC 5.3.1.1). Kinetic experiments suggest that both aldolase-bound glyceraldehyde-3-phosphate can act as substrate for glyceraldehyde-3-phosphate dehydrogenase. These results are consistent with the notion that there is interaction between these three enzymes both during photosynthetic CO2 fixation and during glycolysis in the chloroplast.

A controlled evaluation of psychoeducational family intervention in a rural Chinese community

BACKGROUND

The shortage of mental health care in rural China might be tackled by community care. This study tests the hypothesis that family intervention increases patients' treatment compliance, which is crucial in community care.

METHOD

A cohort of psychiatric patients were randomly selected to a controlled trial for four months. Compliance rates, clinical and social outcomes were measured double-blindly.

RESULTS

The compliance rate was increased significantly in the trial group, and they had better clinical and social outcomes.

CONCLUSIONS

Family intervention is an effective method of improving treatment compliance and should be an important part of community mental health care.

Analyses and conservation of sequences among the cognate L3 segments of the five United States bluetongue viruses

We determined the complete nucleotide sequences of the cognate L3 double-stranded RNA (ds-RNA) segments of bluetongue virus (BTV) serotypes 2, 11, and 13 encoding the major viral inner capsid protein, VP3. Each cognate L3 segment was 2772 nucleotides long and contained a single open reading frame (ORF) with an initiation codon at nucleotides #18-20 and a termination codon at nucleotides #2721-2723. This ORF can encode the 901-amino acid VP3 protein (103 kDa) with a calculated isoelectric point of 6. Phylogenetic analyses using both the nucleotide and the deduced amino acid sequences of the L3 cognate gene of the five US BTV serotypes indicated that the BTV-2 serotype recently isolated in Florida was more distantly related than BTV-10, 11, 13 or 17. The five US BTV serotypes were derived apparently from two distinct gene pools, findings consistent with their current geographic distribution in North America.

Brn-3b: a POU domain gene expressed in a subset of retinal ganglion cells

A search for POU domain transcription factors in human retina cDNA has led to the identification of Brn-3b, a class IV POU domain protein. Immunohistochemical experiments show that chicken, mouse, rabbit, monkey, and human retinas contain Brn-3b exclusively within a subpopulation of ganglion cells. In the adult mouse brain, Brn-3b is found only within cells in the deep layers of the superior colliculus, in the dorsal periaqueductal gray, and in a small cluster of cells in the brain stem near the area postrema. During the immediate postnatal period, cells containing Brn-3b are distributed in a number of regions within the brain stem and cerebellum. These data suggest that Brn-3b plays a role in determining and/or maintaining the identities of a small number of neurons, including a subset of visual system neurons.

A G-string positive cis-regulatory element in the LpS1 promoter binds two distinct nuclear factors distributed non-uniformly in Lytechinus pictus embryos

The LpS1 alpha and beta genes of Lytechinus pictus are activated at the late cleavage stage of embryogenesis, with LpS1 mRNAs accumulating only in lineages contributing to aboral ectoderm. We had shown previously that 762 bp of 5' flanking DNA from the LpS1 beta gene was sufficient for proper temporal and aboral ectoderm specific expression. In the present study, we identified a strong positive cis-regulatory element at −70 bp to −75 bp in the LpS1 beta promoter with the sequence (G)6 and a similar, more distal cis-element at −721 bp to −726 bp. The proximal ‘G-string’ element interacted with two nuclear factors, one specific to ectoderm and one to endoderm/mesoderm nuclear extracts, whereas the distal G-string element interacted only with the ectoderm factor. The ectoderm and endoderm/mesoderm G-string factors were distinct based on their migratory behavior in electrophoretic mobility shift assays, binding site specificities, salt optima and EDTA sensitivity. The proximal G-string element shared homology with a binding site for the mammalian transcription factor IF1, a protein that binds to negative cis-regulatory elements in the mouse alpha 1(I) and alpha 2(I) collagen gene promoters. Competition experiments using wild-type and mutant oligonucleotides indicated that the ectoderm G-string factor and IF1 have similar recognition sites. Partially purified IF1 specifically bound to an oligonucleotide containing the proximal G-string of LpS1 beta. From our results, we suggest that the ectoderm G-string factor, a member of the G-rich DNA-binding protein family, activates the LpS1 gene in aboral ectoderm cells by binding to the LpS1 promoter at the proximal G-string site.