Neurotensin-like immunoreactivity in the pituitary and hypothalamus of bony fishes

Using an antiserum raised against synthetic neurotensin (NT), the distribution of immunoreactivity in the pituitary and hypothalamus has been examined by immunocytochemistry at light and electron microscope level in a number of species of bony fishes. In most species immunoreactive perikarya were found in the preoptic region of the hypothalamus, with fibres throughout the tuberal hypothalamus and neurohypophysis (neural lobe and median eminence). In the neurohypophysis of teleosts NT-like immunoreactivity was seen in a dense band of fibres bordering the ACTH cells of the rostral pars distalis: absorption controls showed that this was due to the presence of an NT(8-13)-like or xenopsin-like sequence, which, according to electron microscopic observations, was contained in small dense cored vesicles. The antiserum also stained the pituitary ACTH cells of some species, apparently due to cross-reaction with the 17-19 sequence of ACTH. These results suggest that an NT-like peptide may have a role in control of the adenohypophysis in fishes.     

Comparative distribution of substance P (SP) and cholecystokinin (CCK) binding sites and immunoreactivity in the brain of the sea bass (Dicentrarchus labrax).

Specific binding sites for cholecystokinin (CCK) and substance P (SP) were detected in the brain of a marine teleost fish, the sea bass, after in vitro incubation of tissue sections with the tritiated peptides and light microscopic autoradiography. Specific binding sites for [3H]-CCK were detected in the dorsal and ventral telencephalon, in the preoptic, tuberal and posterior hypothalamus, in the optic tectum, in the valvulla cerebelli, in the vagal lobe and further in a dorsal location in the medulla oblongata. Areas rich in [3H]-SP binding were located in the ventral telencephalon, in the entire hypothalamic and thalamic region, in the midbrain tegmentum, in the optic tectum, in the valvulla cerebelli and in the medulla oblongata. The distribution of these binding sites seemed to match fairly well with the location of the corresponding immunoreactive elements, although some minor mismatches could be observed. These autoradiographic findings provide the first anatomical evidence for the presence of CCK-like and SP-like binding sites in the brain of a teleost fish.     

Hydroxymethylglutaryl coenzyme A reductase activity of adult Hymenolepis diminuta

The occurrence of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase in adult Hymenolepis diminuta was demonstrated. This activity was negligible in the cestode's cytosolic fraction but was noted when the mitochondrial or microsomal fraction served as the enzyme source. The predominant localization of HMG-CoA reductase activity was with the microsomal fraction. This fraction did not contain appreciable mitochondrial contamination based on the distribution of marker enzymes. The enzymatic nature of HMG-CoA conversion to mevalonic acid by either fraction was apparent because the reaction was heat labile and responded linearly to time of assay and protein content. The enzymatic reduction of HMG-CoA absolutely required NADPH when either fraction was assayed. The lesser activity of the mitochondrial fraction was membrane-associated. The predominant localization of HMG-CoA reductase activity with microsomal membranes and its separation with the membranous component of the mitochondrial fraction suggest that mitochondrial activity reflects the presence of microsomal membranes. In its predominant localization and pyridine nucleotide requirement, the cestode's HMG-CoA reductase activity resembles that of mammalian systems. The finding of HMG-CoA reductase provides an enzymatic mechanism for the intermediate conversion of HMG-CoA to mevalonic acid that would be needed for acetate-dependent isoprenoid lipid synthesis by adult H. diminuta.     

Comparative effects of trichothecene mycotoxins on bovine platelet function: Acetyl T-2 toxin,a more potent inhibitor than T-2 toxin

The effects of the trichothecene mycotoxins (acetyl T-2 toxin, T-2 toxin, HT-2 toxin, palmityl T-2 toxin, diacetoxyscirpenol (DAS), deoxynivalenol (DON), and T-2 tetraol) on bovine platelet function were examined in homologous plasma stimulated with platelet activating factor (PAF). The mycotoxins inhibited platelet function with the following order of potency: acetyl T-2 toxin > palmityl T-2 toxin = DAS > HT-2 toxin = T-2 toxin. While T-2 tetraol was completely ineffective as an inhibitor, DON exhibited minimal inhibitory activity at concentrations above 10×10^?4M. The stability of the platelet aggregates formed was significantly reduced in all mycotoxin treated platelets compared to that of the untreated PAF controls. It is suggested that the increased sensitivity of PAF stimulated bovine platelets to the more lipophilic mycotoxins may be related to their more efficient partitioning into the platelet membrane compared to the more hydrophilic compounds.     

An extensive review on antifungal approaches in the treatment of mucormycosis

During the period of COVID-19, the occurrences of mucormycosis in immunocompromised patients have increased significantly. Mucormycosis (black fungus) is a rare and rapidly progressing fungal infection associated with high mortality and morbidity in India as well as globally. The causative agents for this infection are collectively called mucoromycetes which are the members of the order Mucorales. The diagnosis of the infection needs to be performed as soon as the occurrence of clinical symptoms which differs with types of Mucorales infection. Imaging techniques magnetic resonance imaging or computed tomography scan, culture testing, and microscopy are the approaches for the diagnosis. After the diagnosis of the infection is confirmed, rapid action is needed for the treatment in the form of antifungal therapy or surgery depending upon the severity of the infection. Delaying in treatment declines the chances of survival. In antifungal therapy, there are two approaches first-line therapy (monotherapy) and combination therapy. Amphotericin B ( 1 ) and isavuconazole ( 2 ) are the drugs of choice for first-line therapy in the treatment of mucormycosis. Salvage therapy with posaconazole ( 3 ) and deferasirox ( 4 ) is another approach for patients who are not responsible for any other therapy. Adjunctive therapy is also used in the treatment of mucormycosis along with first-line therapy, which involves hyperbaric oxygen and cytokine therapy. There are some drugs like VT-1161 ( 5 ) and APX001A ( 6 ), Colistin, SCH 42427, and PC1244 that are under clinical trials. Despite all these approaches, none can be 100% successful in giving results. Therefore, new medications with favorable or little side effects are required for the treatment of mucormycosis.     

Hypertrophic osteoarthropathy in cystic fibrosis.

Seven adult patients with cystic fibrosis who had radiological evidence of hypertrophic osteoarthropathy were reviewed. In five of the patients symptoms were particularly pronounced at times of acute infective exacerbations; appropriate treatment of the infective episodes resulted in reduction or resolution of the bone pain and joint effusions. Despite this symptomatic relief periosteal changes persisted radiologically and their chronic nature was indicated by changes in the midshafts of long bones. Four of the seven patients had transient gynaecomastia or mastalgia related to infective exacerbations. It is hypothesised that a neuroendocrine mechanism--namely, release of vasoactive intestinal polypeptide--might account for the osteoarthropathy.     

Sweat tests to diagnose cystic fibrosis in adults.

Twenty five patients with cystic fibrosis and 25 controls were studied to define a sweat sodium concentration in adults that could be taken as diagnostic of cystic fibrosis. Some of the controls had a sweat sodium concentration of over 50 mmol(mEq)/l, and thus cystic fibrosis should be diagnosed in an adult only when two measurements of sweat sodium concentration are above 70 mmol/l. In cases in which the sweat sodium concentration was borderline a suppression test using fludrocortisone improved the accuracy of diagnosis; this test entails recording the lowest concentration reached after administration of the drug. A scatter diagram of the baseline sweat sodium concentrations plotted against the lowest concentration attained after suppression with fludrocortisone may aid the diagnosis further.     

Monoclonal antibodies to rabbit liver cytochrome P-448

Cytochrome P-448 (mol wt 55,000 Daltons) from rabbit liver was purified to a specific content of 16.6 nmol/mg. Mice were immunised with this preparation, their spleens removed and dissociated lymphocytes hybridised with myeloma cells. Four monoclonal antibodies against cytochrome P-448 were raised and partially characterised. All four antibodies interacted with cytochrome P-448 in intact microsomal fractions and selectively immunoadsorbed cytochrome P-448 from solubilised microsomal preparations. One of the antibodies inhibited benzo[a] pyrene hydroxylase activity in a reconstituted system, one had no effect on activity and two increased activity. The possible applications of such antibodies are discussed.     

Use of protein A-coated colloidal gold particles for immunoelectronmicroscopic localization of ACTH on ultrathin sections

Summary ACTH was localized in dissociated porcine adenohypophysial cells using a novel indirect EM immunocytochemical technique. Incubation of ultrathin resin sections in anti-ACTH was followed by incubation with protein A-coated colloidal gold particles. Protein A binds specifically to the Fc part of the IgG molecule, and thus the ACTH-containing secretory granules became labelled with electron-dense gold particles. With this method, the dissociated porcine ACTH cell was identified as containing numerous round or ovoid 170–300 nm, secretory granules.     

A review of phosphorus efficiency in wheat

More efficient utilization of phosphorus by wheat plants is needed to extend the useful life of the phosphate reserves in the world, to reduce the cost of producing crops, and to improve the value of the grain and the straw produced. In this paper definitions of efficient use of phosphorus by wheat are reviewed, genotypic variation in phosphorus efficiency is reported, some consequences of breeding for greater efficiency are discussed, and ways to select more efficient genotypes are suggested.