Comparative studies on the effects of specific immunoneutralization of endogenous FSH or LH on testicular germ cell transformations in the adult bonnet monkey (Macaca radiata)

PROBLEM: It is yet to be determined clearly whether the two hormones FSH and T act synergistically in the same cell type-the Sertoli cells-to control overall spermatogenesis or influence independently the transformation of specific germ cell types during spermatogenesis in the adult mammal. METHOD: Adult male bonnet monkeys specifically deprived of either FSH or LH using immunoneutralization techniques were monitored for changes in testicular germ cell transformation by DNA flow cytometry. RESULTS: FSH deprivation caused a significant reduction (>40%; P < 0.05) in [H-3] thymidine incorporation into DNA of proliferating 2C (spermatogonial) cells, a marked inhibition (>50%) in the transformation of 2C to primary spermatocytes (4C) and a concomitant, belated reduction (50%) in the formation of round spermatids (1C). In contrast, specific LH/T deprivation led to an immediate arrest in the meiotic transformation of 4C to 1C/HC leading to an effective and significant block (<90%; P < 0.01) in sperm production. CONCLUSION: Thus, LH rather than FSH deprivation has a more pronounced and immediate effect as the former primarily blocks meiosis (4C --> 1C/HC) which controls production of spermatids. These data provide evidence for LH/T and FSH regulating spermatogenic process in the adult primate by primarily acting at specific germ cell transformation steps.

Mapping Post-translational Modifications of Mammalian Testicular Specific Histone Variant TH2B in Tetraploid and Haploid Germ Cells and Their Implications on the Dynamics of Nucleosome Structure

Histones regulate a variety of chromatin templated events by their post-translational modifications (PTMs). Although there are extensive reports on the PTMs of canonical histones, the information on the histone variants remains very scanty. Here, we report the identification of different PTMs, such as acetylation, methylation, and phosphorylation of a major mammalian histone variant TH2B. Our mass spectrometric analysis has led to the identification of both conserved and unique modifications across tetraploid spermatocytes and haploid spermatids. We have also computationally derived the 3-dimensional model of a TH2B containing nucleosome in order to study the spatial orientation of the PTMs identified and their effect on nucleosome stability and DNA binding potential. From our nucleosome model, it is evident that substititution of specific amino acid residues in TH2B results in both differential histone-DNA and histone-histone contacts. Furthermore, we have also observed that acetylation on the N-terminal tail of TH2B weakens the interactions with the DNA. These results provide direct evidence that, similar to somatic H2B, the testis specific histone TH2B also undergoes multiple PTMs, suggesting the possibility of chromatin regulation by such covalent modifications in mammalian male germ cells.

Cell shape changes indicate a role for extrinsic tensile forces in Drosophila germ-band extension.

Drosophila germ-band extension (GBE) is an example of the convergence and extension movements that elongate and narrow embryonic tissues. To understand the collective cell behaviours underlying tissue morphogenesis, we have continuously quantified cell intercalation and cell shape change during GBE. We show that the fast, early phase of GBE depends on cell shape change in addition to cell intercalation. In antero-posterior patterning mutants such as those for the gap gene Krüppel, defective polarized cell intercalation is compensated for by an increase in antero-posterior cell elongation, such that the initial rate of extension remains the same. Spatio-temporal patterns of cell behaviours indicate that an antero-posterior tensile force deforms the germ band, causing the cells to change shape passively. The rate of antero-posterior cell elongation is reduced in twist mutant embryos, which lack mesoderm. We propose that cell shape change contributing to germ-band extension is a passive response to mechanical forces caused by the invaginating mesoderm.

Growth response of Heterobranchus longifilis (Valenciennes, 1840) fingerlings fed raw and boiled Mucuna cochinchinensis seed meal

Feeding trial was conducted in static water to assess the growth of H. longifilis fingerlings fed different I inclusion levels of mucuna seed meal (MSM). Raw and boiled MSM were used in the diets at 10%, 20%, 30% and 40% inclusion levels and the performance of fish fed these diets was compared with fish fed a fishmeal-based diet which contained 40% protein. All diets were prepared to be isonitrogenous and isocaloric A two by five factorial experiment with three replicates using ten fish of average initial weight 1 .46g was carried out. Daily fish ration of five percent body weight was administered two times for eight weeks. The specific growth rate in diets 1 (control) and 6(10% boiled MSM) were similar and significantly (P<0.05) higher than the other dietary groups. The significantly lower growth performance of fish fed diets containing higher inclusion levels of both raw and boiled MSM might be due to incomplete elimination of the antinutritional factors present in MSM by boiling. Other methods of processing MSM to improve its nutritive value should be investigated. (7 page document)

Clinical factors associated with a Candida albicans Germ Tube Antibody positive test in Intensive Care Unit patients

Background: Poor outcomes of invasive candidiasis (IC) are associated with the difficulty in establishing the microbiological diagnosis at an early stage. New scores and laboratory tests have been developed in order to make an early therapeutic intervention in an attempt to reduce the high mortality associated with invasive fungal infections. Candida albicans IFA IgG has been recently commercialized for germ tube antibody detection (CAGTA). This test provides a rapid and simple diagnosis of IC (84.4% sensitivity and 94.7% specificity). The aim of this study is to identify the patients who could be benefited by the use of CAGTA test in critical care setting. Methods: A prospective, cohort, observational multicentre study was carried out in six medical/surgical Intensive care units (ICU) of tertiary-care Spanish hospitals. Candida albicans Germ Tube Antibody test was performed twice a week if predetermined risk factors were present, and serologically demonstrated candidiasis was considered if the testing serum dilution was >= 1: 160 in at least one sample and no other microbiological evidence of invasive candidiasis was found. Results: Fifty-three critically ill non-neutropenic patients (37.7% post surgery) were included. Twenty-two patients (41.5%) had CAGTA-positive results, none of them with positive blood culture for Candida. Neither corrected colonization index nor antifungal treatment had influence on CAGTA results. This finding could corroborate that the CAGTA may be an important biomarker to distinguish between colonization and infection in these patients. The presence of acute renal failure at the beginning of the study was more frequent in CAGTA-negative patients. Previous surgery was statistically more frequent in CAGTA-positive patients. Conclusions: This study identified previous surgery as the principal clinical factor associated with CAGTA-positive results and emphasises the utility of this promising technique, which was not influenced by high Candida colonization or antifungal treatment. Our results suggest that detection of CAGTA may be important for the diagnosis of invasive candidiasis in surgical patients admitted in ICU.

Improvement in the nutritive quality of soyabean meal by co-ensiling with under-utilized fish discards

Improvement in the nutritive value of soybean meal was investigated by Co-ensiling it with underutilized trash fish discards (gizzard shad)at different proportions. The following proportions of gizzard shad to soybean meal were used; (a) 100% gizzard shad + acid combination (b)80% gizzard shad +20% soybean meal & 10% WB (c) 60% gizzard shad + 40% soybean meal & 10% WB (d) 100% gizzard shad without acid combination. Co-ensiling was achieved by adding sufficient acid to produce a paste. Products were neutralized by addition of 2% (by weight) calcium hydroxide and drying was affected by freeze-drying.The dried silage products were stored at low temperatures. Products were analysed for proximate composition and amino acid composition.The amino acid composition and ration of essential amino acid. Non essential amino acid (EAA/NEAA) was used as index of nutritive quality. Also essential amino acid profile of the co-ensiled products were compared with essential amino acid requirement of some warmwater fish species to estimate their nutritive usefulness for these species

Effects of fish-meal, cow blood-meal, and sorghum diets on food utilization and growth of cage cultured Sarotherodon niloticus

The growth responses and feed utilization of Sarotherodon niloticus held in metal cages in a pond and fed diets containing fish-meal, cow blood-meal or sorghum was studied. Results indicate that the best growth, feed conversion and protein efficiency ratio were obtained with the diet containing 60% fish-meal. The growth performance of fish on 40% fish-meal, and 40% and 60% blood meal were not significantly different, and were quite close to the performance with 60% fish-meal. The growth and food utilization of fish on 84% sorghum diet was significantly lower than the rest. The Caged fish without supplemental feeding had a light gain in weight. All fish with supplemental feeding appeared healthy. It is concluded that cow blood meal at 40% or 60% inclusion in diet can adequately replace fish-meal in S. niloticus supplemental diet in pond culture

Commercial production of fish meal from fish waste

The importance of fish meal production as a means of reducing fish waste currently being experienced in the fisheries subsector is discussed. Cost estimate for Nigeria establishing a fish meal manufacturing plant and suggestions on rational execution of the project are presented. If properly located and well managed, the project will serve to convert fish waste to cash in the industrial fishery

The growth and survival rate of Oreochromis niloticus fries fed (private) with varying percentages of Leucaena leucocephala leaf meal based diets

A-ten-week feeding trial was carried out to evaluate the growth and survival rate of Oreochromis niloticus fed with varying percentage levels of Leucaena leucocephala leaf meal based diets. The substitution rates of L.leucocephala leaf meal for groundnut cake in the various diets were 0% - Diet 1, 25% - Diet 2, 50% - Diet 3 and 75% - Diet 4. Ten fries with an average weight of 0.44g were stocked at the rate of 10 fish per bowl and fed at 5% body weight. Diet 1 with 0% inclusion of Leucaena leaf meal gave a significant difference (P>0.05) in growth and survival rate compared with diets 2, 3 and 4. The water quality parameters recorded were appropriate for fish culture

The growth and survival rate of (private) Oreochromis niloticus fingerlings fed with varying percentages of Leucaena leucocephala leaf meal based diets

A-ten-week feeding trial was carried out to evaluate the growth and survival rate of Oreochromis niloticus fed with varying percentage levels of Leucaena leucocephala leaf meal as a substitute for groundnut cake. The levels in the various diets were 0% - Diet 1, 25% - Diet 2, 50% - Diet 3 and 75% - Diet 4. Ten fingerlings with an average weight of 0.44g were stocked at the rate of 10 fish per bowl and fed at 5% body weight. Diet 1 with 0% inclusion of leucaena leaf meal gave a significant difference (P>0.05) in growth and survival rate compared with diets 2, 3 and 4. The water quality parameters recorded were appropriate for fish culture

An investigation of the effect of replacing fish meal with soyabean meal, groundnut cake and blood meal at varied proportion on growth and food utilization of the Clarias anguillaris fingerlings fed in outdoor hapas

Fingerlings of Clarias anguillaris obtained from a homogenous source through induce breeding and each with a mean weight of 2.8g were stocked in ten hapas each measuring 1.0x1.0m in outdoor concrete tank and were fed for eight (8) weeks. Results shows that the best growth rate was recorded among fingerlings fed fish meal as the only protein source (TD5) while DT2 containing soya bean, groundnut cake (40%), blood meal as the protein sources came next. The growth rate of fingerlings fed DT2 (40 % groundnut cake, 10% soyabean meal and 10% blood meal) was higher than those fed DT4 containing 10% fish meal but lower than those fed DT5 which has fish meal as its sole source of protein (53.0%). Analysis of various growth parameters like SGR, FCR and PER. shows that DT5 was the overall best diet but there was no significant statistical difference in weight gained by fish fed the five diets (P <0.05)

Effect of fish meal in formulated diet on the growth of Heterotis niloticus in semi-intensive pond culture system

The aim of the investigation is to know the percentage of fish meal required to support the best growth of Heterotis niloticus in a semi intensive pond culture system. To achieve this, feed was formulated with equal percentages of blood meal, and corn meal and varying levels of fish meal. The experiment was in four treatments. Results showed that the mean weight gained was directly proportional to the quantity of fish meal made available to the fish fence 31.58g, 33.79g, 45.15g and 51.24g were recorded for treatments I, II, III and IV respectively. Result from this study when compared with previous works, shows that size of the water body to a greater extent affects the growth. The availability of fish meal in the feed made it more acceptable to the fish and hence a commensurate conversion in to flesh. The analysis of variance showed that there is significant difference in the growth performance in the treatments

The effect of replacement of soyabean meal with blood meal on the growth of mudfish Clarias anguillaris (L) fingerlings

Blood meal and full fat soyabean meal were mixed in different proportions to give 0%, 10%, 25%, 50%, 75%, 90% and 100% meal in the protein fraction of the diet and fed to Claria anguillaris fingerlings in floating hapas. The growth performance of the fingerlings were monitored for 84 days. At the end of the experiment the mean weight of the fingerlings increased in the level of blood meal up to 50% blood meal in the diet after which there was a decline in the mean weight of the fish. This same level of blood meal gave the best specific growth rate, feed conversion efficiency and protein efficiency ratio. Thus the nutritive value of blood meal was enhanced by the addition of an equal level of full fat soyabean meal in the diet

Substituting fish meal with grasshopper meal in the diet of Clarias gariepinus fingerlings

The effect of inclusion of grasshopper meal on the growth, feed conversion ratio and survival of Clarias gariepinus fingerlings of mean weight 9.71g was investigated. The results show that the best growth and food utilization indexes were recorded in the fingerling fed with 10% grasshopper meal and 30% fish meal, while the poorest growth and food utilization indexes were recorded with the diet containing 25% grasshopper meal and 15% fish meal. The best survival of 100% was observed in the diet containing 30% grasshopper meal and 10% fish meal while the worst survival of 73.3% was observed in the diet containing 25% grasshopper meal and 15% fish meal

Growth performance of Clarias gariepinus fingerlings fed earthworm meal (Lumbricus terrestis)

An investigative study was carried out on the growth performance and nutrient utilization of (Clarias gariepinus) fingerlings fed earthworm meal as a replacement for fish meal. A large collection of earthworm was done during the peak of rainy season (July-August) within the University environment. They were then ovens dried. Used as test ingredients were 0% (Diet 1) 50% (Diet 2) and 1000% (Diet u). The trials were conducted in plastic bowls (40-L capacity) under laboratory conditions. The diets were fed at 5% body weight to fish; the fish were stocked at 10 fish per bowl. The evaluation of the growth parameters showed that there was no significant difference (P>0.05) in mean weight gain (MWG) specific growth rate (SGR) food conversion ratio (FCR), protein efficiency ration (PER) and survival among the fish fed the experimental diets