Immunological studies of insect metamorphosis. II. The role of a sex-limited blood protein in egg formation by the Cecropia silkworm

1. In the pupal stage of the cecropia silkworm, antigen 7, a protein with the solubility characteristics of an albumin, is present in female blood in approximately a thousand times higher concentration than in the blood of males. Antigen 7 is undetectable in the blood of larvae of either sex. It first appears in the blood after the larva has spun its cocoon, and is present throughout all subsequent stages of metamorphosis. Late in the pupal-adult transformation, when the eggs are produced, the concentration of antigen 7 in female blood decreases significantly. 2. An antigen which could not be distinguished from antigen 7 immunologically is present in solution in the yolk of unfertilized eggs. 3. In females which, by ovariectomy, were prevented from forming eggs, the concentration of antigen 7 in the blood increased during the usual period of egg formation rather than undergoing the normal decrease. Ovaries transferred to the hemocoel of males produced eggs but were unable to incorporate antigen 7 in the yolk unless a detectable amount of the protein was present in the blood. The ovaries of polyphemus females which had been transfused with cecropia blood incorporated cecropia antigen 7 into the eggs they produced. These lines of evidence indicate that antigen 7 is secreted into the blood by some tissue other than the ovaries, and that it is subsequently drawn from the blood and deposited in the yolk. 4. The concentration of antigen 7 in the clear, liquid fraction of the yolk is four times higher than the maximum concentration attained in the blood during metamorphosis, and twenty times higher than that of the blood at the conclusion of egg formation. The protein thus appears to be transferred from blood to yolk against a concentration gradient.     

Rapid Diagnosis of Bacteremia

Early appropriate treatment of bacteremia is important in minimizing morbidity and mortality. Standard blood culture methods are not optimal since several days are often required for recovery and identification of organisms which may be present in the blood. The use of a membrane filter technique allows one to grow any organisms present in blood much more rapidly than by broth or pour plate culture. Furthermore, growth is in the form of typical colonies on the surface of solid media, and a series of rapid diagnostic tests may be used to provide speedy identification. Use of membrane filters also facilitates removal by washing of normal antibacterial factors and antimicrobial drugs which may be present in blood. Although the filter technique yielded the most rapid growth, broth culture and whole blood pour plates yielded more positive cultures and use of all three systems was necessary for maximal recovery of organisms in blood cultures. Data on quantitative aspects of bacteremia in the antimicrobial era are also presented. The number of low level bacteremias (10 colonies/ml or less) is surprisingly high. This is particularly true for gram-negative bacilli; antimicrobial therapy at the time of culture undoubtedly influenced these results greatly. Finally, suggestions are given for a much simpler and more efficient membrance filter blood culture technique.     

Rapid Diagnosis of Bacteremia

Early appropriate treatment of bacteremia is important in minimizing morbidity and mortality. Standard blood culture methods are not optimal since several days are often required for recovery and identification of organisms which may be present in the blood. The use of a membrane filter technique allows one to grow any organisms present in blood much more rapidly than by broth or pour plate culture. Furthermore, growth is in the form of typical colonies on the surface of solid media, and a series of rapid diagnostic tests may be used to provide speedy identification. Use of membrane filters also facilitates removal by washing of normal antibacterial factors and antimicrobial drugs which may be present in blood. Although the filter technique yielded the most rapid growth, broth culture and whole blood pour plates yielded more positive cultures and use of all three systems was necessary for maximal recovery of organisms in blood cultures. Data on quantitative aspects of bacteremia in the antimicrobial era are also presented. The number of low level bacteremias (10 colonies/ml or less) is surprisingly high. This is particularly true for gram-negative bacilli; antimicrobial therapy at the time of culture undoubtedly influenced these results greatly. Finally, suggestions are given for a much simpler and more efficient membrance filter blood culture technique.     

Particle-fluid suspension model of blood flow through stenotic vessels with applications

The present study deals with the problem of blood flow through stenotic vessels when blood is represented by a particle-fluid suspension model, i.e. a suspension of red blood cells in plasma. The expressions for the dimensionless resistance to flow, the wall shear stress, and the shearing stress on the wall at the maximum height of the stenosis are derived. The results obtained in the analysis are discussed in brief, both qualitatively and quantitatively by comparison with other theories. It is observed that the magnitudes of the blood flow characteristics significantly increase with an increase in the red cell concentration. The importance of the decreasing vessel diameter is also pointed out. Finally, to observe the biological relevance of the analysis, the results obtained are used to compute the blood flow characteristics for normal and diseased blood using the experimental data from published literature and results are compared with those computed using the present theoretical approach.     

Ultrastructural features of the midgut epithelium of females Lutzomyia intermedia (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae).

A morphological study of the midgut of Lutzomyia intermedia, the primary vector of cutaneous leishmaniasis, in southeast Brazil, was conducted by light, scanning and transmission electron microscopy. The midgut is formed by a layer of epithelium of columnar cells on a non-cellular basal lamina, under which there is a musculature, which consists of circular and longitudinal muscular fibers. A tracheolar network is observed surrounding and penetrating in the musculature. Females were examined 12, 24, 48, 72 h and 5 days following a blood meal and were analyzed comparatively by transmission electron microscopy with starved females. In starved females, the epithelium of both the anterior and posterior sections of the midgut present whorl shaped rough endoplasmic reticulum. The posterior section does not present well-developed cellular structures such as mitochondria. Observations performed at 12, 24, 48 and 72 h after the blood meal showed morphological changes in the cellular structures in this section, and the presence of the peritrophic matrix up to 48 h after the blood meal. Digestion is almost complete and a few residues are detected in the lumen 72 h after blood feeding. Finally, on the 5th day after the blood meal all cellular structures present the original feature resembling that seen in starved sand flies. Morphometric data confirmed the morphological observations. Mitochondria, nuclei and microvilli of midgut epithelial cells are different in starved and blood fed females. The mitochondria present a similar profile in the epithelium of both the anterior and posterior section of the midgut, with higher dimension in starved females. The cell microvilli in the posterior section of the midgut of starved females are twice the size of those that had taken a blood meal. We concluded that there are changes in the midgut cellular structures of L. intermedia during the digestion of blood, which are in agreement with those described for other hematophagous diptera.     

Ganglioside GD3 in the serum of tumor patients

Gangliosides of normal human blood serum and of blood serum of tumour hosts were studied. It has been shown the first time that ganglioside (NeuAc)2LacCer is present in the blood serum of different tumour hosts, but is absent in normal blood serum. The reasons for the appearance of this ganglioside in blood serum are discussed.     

Proteolytic enzymes of female Anopheles: Biphasic synthesis,regulation, and multiple feeding

Two types of trypsin activity were detected in Anopheles albimanus, a constitutive and an inductive component, which have identical immunopatterns. The constitutive trypsin in synthesized shortly after eclosion and is retained in the midgut epithelial cells. The inductive trypsin is synthesized and released continuously after a blood meal has been ingested; maximal activities vary between 12 h and 18 h after a blood meal. Once digestion is completed, trypsin is excreted, but the constitutive trypsin level is restored within 24 h, before the next blood meal is taken. In A. gambiae, A. Stephensi, and A. quadrimaculatus, the constitutive trypsin component is also present, but at much lower levels. In A. albimanus fed multiple blood meals at 24 h intervals, trypsin oscillates at nearly maximal levels as long as blood is present in the midgut and depending on the ovarian status. Expression of the two trypsin components in A. albimanus was found to be independent of the neurosecretory system, but synthesis of the constitutive trypsin appears to require the presence of the corpora allata. In all species tested, chymotrypsin is secreted after a blood meal in a similar temporal pattern as trypsin, but it is never present before the blood meal. Reinvestigating several aedine species for the presence of chymotrypsin by using different substrates revealed measurable quantities in blood-fed females compared to earlier reports. Equally, aminopeptidase activity is present in all species tested and characterized by a constitutive component. Its activities follow different temporal patterns than the endopeptidases. © 1995 Wiley-Liss, Inc.     

Inability of large granular lymphocytes to recirculate through blood-lymph barriers

The level of large granular lymphocytes (LGL) has been determined in thoracic lymph duct and peripheral blood of cattle. It has been shown that in contrast to the blood, these cells are present in the lymph in minor quantities. Unlike blood LGL, lymph LGL have smaller granules in cytoplasm. It is concluded that LGL do not recirculate from blood to central lymph.     

New experimental rabbit model with PTFE grafts interpositioned in infrarenal abdominal aorta--influence of hyperlipidemia in prosthetic grafts

The major obstacle to clinical application of artificial blood vessel grafts with inside diameter of less than 4 mm is neogenic intimal hypertrophy at anastomotic sites. With the aim of preventing this artificial blood vessel graft anatomotic intimal hypertrophy, attempts have been made to improve surgical techniques and develop new materials for sutures and the grafts themselves. In the assessment of the preventive effects of various measures on anastomotic intimal hypertrophy, it is desirable to minimize variation in preoperative arteriosclerotic changes and uniform hemodynamics after vessel replacement surgery among the subjects. The present authors succeeded in creating an infrarenal abdominal aorta replacement model that meets these requirements using rabbits, and conducted experiments using this model to assess the effects of hyperlipidemia on anastomotic intimal hypertrophy. The anastomotic intimal hypertrophy lesion in the present rabbit infrarenal abdominal aorta replacement model is both morphologically and histologically similar to that found in human artificial blood vessel graft anastomotic sites. In addition, this model permits the easy obtain of animals showing the same hemodynamic status after vascular surgery. For these reasons, the present model is expected to serve well as an experimental model of artificial blood vessel graft anastomotic intimal hypertrophy.     

Investigation of volatile biomarkers in lung cancer blood using solid-phase microextraction and capillary gas chromatography-mass spectrometry

In the present work, solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) was developed for investigation of lung cancer volatile biomarkers. Headspace SPME conditions (fiber coating, extraction temperature and extraction time) and desorption conditions were optimized and applied to determination of volatiles in human blood. To find the biomarkers of lung cancer, investigation of volatile compounds in lung cancer blood and control was performed by using the present method. Concentrations of hexanal and heptanal in lung cancer blood were found to be much higher than those in control blood. The two molecules of hexanal and heptanal were regarded as biomarkers of lung cancer. By comparison of volatiles in breath and in blood, it is demonstrated that hexanal and heptanal in breath were originated from blood and screening of lung cancer by breath analysis be feasible. These results show that SPME/GC-MS is a simple, rapid and sensitive method very suitable for investigation of volatile disease markers in human blood.     

Hemodynamic effects of centrally administered, norcocaine in the rat.

Norcocaine is the N-demethylated metabolite of cocaine. It is present in the CNS and is reported to be pharmacologically active. The present study was designed to evaluate the cardiovascular actions of norcocaine following central administration. Wistar Kyoto (WKY) rats were anesthetized with pentobarbital and instrumented for measurement of blood pressure and renal and hindlimb blood flow (via Doppler flowprobes). A cerebroventricular cannula was placed in the lateral ventricle for drug administration. Cocaine or norcocaine was administered centrally in a dose range of 0.025 to 4.0 mg/kg. Under the above experimental conditions, 4.0 mg/kg of norcocaine decreased blood pressure without a significant change in either hind limb or renal blood flow. Central administration of cocaine also produced a similar depressor response. In conscious, unrestrained rats, cocaine produced a pressor response while norcocaine did not significantly alter blood pressure. The depressor response to both cocaine and norcocaine in the anesthetized animal is speculated to be due to the local anesthetic properties of the drugs.     

High-speed sensing of microliter-order whole-blood viscosity using laser-induced capillary wave

The present paper introduces an innovative contact-free optical viscosity measurement technique, laser-induced capillary wave (LiCW) using pulsed YAG laser as a heating source, to measure whole-blood viscosity with only a microliter-order sample volume and measurement time on the millisecond order. In this method, interfering pulsed laser beams heat a whole-blood sample and generate a capillary wave, the amplitude of which is less than 10 nm with wavelength of 80–100 μm in the present experiment, caused by a spatially sinusoidal temperature distribution. The damped oscillation of the capillary wave, which is detected by a diffracted probing laser beam at the heated area, provides information regarding the viscosity and surface tension of the whole blood. To demonstrate the validity of the present laser-induced capillary wave viscometer, the viscosity of human whole blood taken from two healthy donors having different hematocrit values was measured using 90 μl sample volumes at 37°C. To consider the feasibility of the present technique for blood rheological studies, we discuss the characteristics of LiCW regarding the non-Newtonian behavior of blood, the velocity boundary layer, the existence of a free surface, and the temperature increase of the blood, and also demonstrate the capability of the method to sense the temporal evolution of blood viscosity with sampling frequency of 0.25 Hz.     

In vitro hydrolysis of RR,SS-threo-methylphenidate by blood esterases--differential and enantioselective interspecies variability

Enantioselective in vitro hydrolysis of methylphenidate (MPH) by the blood esterases of seven mammalian species is reported. The species included rats, rabbits, dogs, cattle, horses, monkeys, and humans. In vitro incubations up to 8 h were carried out in plasma, red blood cells, and whole blood of the various species. Enantioselective differences were evident among the different species on comparison of the data obtained from the three biological fluids. The esterases present in plasma appeared to show greater activity in the hydrolysis of MPH in all species where comparison with the other two biofluids was possible. Only in the case of humans did esterases present in plasma and red blood cells demonstrate opposite enantioselectivity in the hydrolysis of MPH. Thus after 8 h incubation, the RR-MPH/SS-MPH ratios in plasma and red blood cells were 0.31 and 1.16, respectively.     

The occurence of cystinylglycine in blood plasma

Cystinylglycine has been identified as a minor ninhydrin-positive component of deproteinized blood plasma from human, bovine, rat and rabbit blood. The amount present in human blood plasma is approximately one-fifth of that of cystine and is not significantly correlated with age or with the cystine level.     

Simple and rapid measurement of platelet-activating factor (PAF) in whole blood.

A simple assay of platelet-activating factor (PAF) in whole blood was developed, employing acetone extraction and thin layer chromatography (TLC) purification of blood sample. The activity of acetylhydrolase present in blood sample was almost completely suppressed by ice-cold acetone extraction, and other inhibitory substances interfering the activity of PAF were effectively removed from the acetone extract by TLC. Then, the treated samples were subjected to a conventional PAF bioassay using rabbit platelets. The recovery rate of PAF by the above procedure was constant and feasible (46-48%). The lower limit of the present assay was estimated to be 1.0 x 10(-10) M. Employing the present method, it was able to determine the amount of PAF in blood (1.2-6.0 x 10(-10) M) of 6 out of 14 septic patients, while no significant PAF activity was detected in the samples from 6 healthy subjects. These results indicate a potential application of the present method in the clinical assay of PAF in blood.     

The occurrence of cystinylglycine in blood plasma.

Cystinylglycine has been identified as a minor ninhydrin-positive component of deproteinized blood plasma from human, bovine, rat and rabbit blood. The amount present in human blood plasma is approximately one-fifth of that of cystine and is not significantly correlated with age or with the cystine level.     

Protochordate leucocytes: a review

The present review considers the structure, site of formation and functions of protochordate blood cells/coelomocytes. Details of the circulatory and coelomic system are also given where appropriate. In the hemichordates, blood cells are absent but a single type of amoebocyte is present in the coelomic cavity. A similar situation exists in cephalochordates and these cells appear to play an important role in maintaining the animal free from infection. In the urochordates, several morphologically distinct types of blood cells (haemocytes) exist, some of which store vanadium. At present little is known concerning the phylogeny and ontogeny of the different cell types in these groups.     

Parasympathetic reflex vasodilatation in rat submandibular gland

The present study was designed to investigate 1) whether parasympathetic reflex vasodilatation occurs in the submandibular gland (SMG) in deeply urethan-anesthetized, cervically vagotomized, and sympathectomized rats when the central cut end of the lingual nerve (LN) is electrically stimulated and 2) to what extent the neural mechanisms underlying such responses are the same as those involved in the response to direct stimulation of the chorda-LN (CLN). Stimulation of each nerve separately elicited a marked blood flow increase in SMG. Section of the chorda tympani abolished the SMG blood flow response but had no effect on the lip blood flow increase evoked by LN stimulation. Section of the CLN abolished the SMG blood flow increases evoked by stimulation of either nerve. The SMG blood flow increases (regardless of whether they were evoked by LN or CLN stimulation) were markedly reduced by the autonomic cholinergic ganglion blocker hexamethonium. The present study demonstrates that a parasympathetic reflex vasodilator mechanism is present in the rat SMG and that it can express its effects under deep general anesthesia.     

Red cell maturation: loss of a reticulocyte-specific membrane protein

A protein present in red cell ghost membranes from reticulocyterich blood disappears from the membrane $\text{in vivo}$ as the reticulocytes mature. This protein, with an estimated molecular weight of 33,000, is not present in mature circulating red blood cells. It is not associated with the ribosomes present in the reticulocyte.     

Blood pressure changes after intravenous administration of cell-free hemoglobin A and hemoglobin H in the rat.

Hemoglobin H (HbH) is a tetramer of four beta chains (present in erythrocytes of alpha thalassemia), whereas hemoglobin A is a tetramer of two alpha and two beta chains. Since HbH is known to bind four times more nitric oxide (a vasodilator) at its sulfhydryls compared to HbA, the present studies were conducted to see the effect of HbH and HbA on rat blood pressure. The acute administration (20-2000 nmol/kg) of both HbH and HbA produced a dose-dependent effect on blood pressure. The net change in mean arterial pressure was significantly higher with HbH compared to HbA. Partially nitrosylated (in which SH groups are occupied with NO) HbH retained the property of raising blood pressure to some extent while HbA lost this property. Completely nitrosylated (in which both heme and SH groups are occupied with NO) derivatives of both HbH and HbA reduced the blood pressure to the same extent. The preliminary studies with chronic administration of HbA and HbH resulted in nonsignificant increase in blood pressure. It is concluded that these findings may explain the earlier observations of increased risk of hypertension in individuals with alpha thalassemia.