Mechanical study of blood flow through a permeable capillary with slippery wall

This research presents the mechanical behavior of blood flow through capillary having smooth inner surface. In this study modelling of blood flow via permeable and lubricated capillary caused by nutrients re-absorption has been done by the help of laws of momentum and mass. The nutrients re-absorption is assumed to be constant and inner walls of the capillary are smooth and slippery therefore slip condition on the velocity and constant rate in vertical direction at the wall has considered. The Kelvin Voigt model is employed to simulate blood flow via capillaries, and results for pressure, blood flow pattern, and shear force necessary for blood flow are discovered by recursive approach. Numerical results for nutrient re-absorption from the blood and impact of smooth and slippery surfaces on blood flow are shown through graphs. The novelty of the research invents that the smoothness and slickness of capillary wall is a crucial presumption to examine the blood as non-Newtonian fluid via capillary.

Synthesis of silver nanoparticles using Emilia sonchifolia plant for treatment of bloodstream diseases caused by Escherichia coli

OBJECTIVES

Among infectious diseases, bloodstream infection (BSI) caused by gram-negative bacteria (E. coli) is the leading cause of death worldwide. However, the bacteria have produced resistance to many of these antibiotics. Thus, the present study aimed to develop silver nanoparticles (AgNPs) loaded with Emilia sonchifolia (ES) extract (ES-AgNPs) to treat BSI efficiently.

METHODS

AgNPs were synthesized by reduction of silver nitrate (AgNO₃) solution by ES extract. Furthermore, these ES-AgNPs were characterized for particle size and zeta potential, crystallinity by powder X-ray diffraction (P-XRD) technique, in vitro antibacterial activity, time-kill assay, film bio adhesion, and fluorescence assay.

RESULTS

Surface plasmon resonance (SPR) has been used to confirm the formation of AgNPs by seeing a shift in colour to dark-brown. The ES-AgNPs displayed a mean particle size of 137±3nm (PDI of 0.168±0.02) and zeta potential of 18.2±0.8mV. Furthermore, according to P-XRD results, the developed AgNPs are highly crystalline. The ES-AgNPs showed effective antibacterial action against E. coli with minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of 0.4±0.02μg/mL and 0.8±0.03μg/mL, respectively. In addition, ES-AgNPs inhibited biofilm formation and bacterial adhesion in a dose-dependent manner with 100% inhibition obtained in 48h at MBC.

CONCLUSIONS

Present research work revealed that the ES-AgNPs obtained by green synthesis holds a prominent antibacterial activity in the treatment of BSIs caused by E. coli and they may be used as a competent substitute for current treatments. However, further, in vivo antibacterial studies are required to establish its efficacy in the treatment of BSIs.

Application of creeping flow through a linearly absorbing slit filled with porous medium to diseased renal tubules

In this paper, we have discussed the flow of a Newtonian fluid through a slit filled with porous medium and linearly reabsorbing porous walls. The study is motivated by fluid flow in diseased renal tubules in a kidney. Due to diseases, some fibrous material, fatty substances and solid waste particles, etc., may get suspended in tubule channel as well as on the pores of the wall, resulting in the porous filling in the slit and biofouling, respectively. In this study, the absorption at the wall is assumed to follow a linear pattern and the fluid is assumed to be entering the channel at a prescribed initial flow rate. The problem of the two-dimensional fluid flow is formulated using stream function, and inverse solution method is applied to obtain an exact solution of the fourth-order compatibility equation. Some special cases are also deduced from the obtained results and compared with available results from literature. Expressions for various physically relevant quantities like fluid velocities, volume flow rate, fractional reabsorption, leakage flux and pressure distribution are obtained. The results are used to demonstrate how medium porosity and biofouling parameter may affect average pressure differences in the renal tubules of a rat kidney. Finally, the results are presented graphically and effects of changing various parameters on the flow are analysed. We have also deduced some special cases when the wall reabsorption is uniform, and when there is no medium porosity. We have shown these special cases match with the already present results in the literature.

Quantifying drug tissue biodistribution by integrating high content screening with deep-learning analysis

Quantitatively determining in vivo achievable drug concentrations in targeted organs of animal models and subsequent target engagement confirmation is a challenge to drug discovery and translation due to lack of bioassay technologies that can discriminate drug binding with different mechanisms. We have developed a multiplexed and high-throughput method to quantify drug distribution in tissues by integrating high content screening (HCS) with U-Net based deep learning (DL) image analysis models. This technology combination allowed direct visualization and quantification of biologics drug binding in targeted tissues with cellular resolution, thus enabling biologists to objectively determine drug binding kinetics.

A Jeffrey Fluid Model for a Porous-walled Channel: Application to Flat Plate Dialyzer

Creeping motion of a Jeffrey fluid in a small width porous-walled channel is presented with an application to flow in flat plate hemodialyzer. Darcy's law is used to characterize the fluid leakage through channel walls. Using suitable physical approximations, approximate analytical solution of equations of motion is obtained by employing perturbation method. Expressions for velocity field and the hydrostatic pressure are obtained. Effects of filtration coefficient, the inlet pressure and Jeffrey fluid parameters on the flow characteristics are discussed graphically. The derived results are used to study the flow of filtrate in a flat plat hemodialyzer. Using the derived solutions, theoretical values of the filtration rate and the mean pressure difference in the hemodialyzer are calculated. On comparing the computed results with the available experimental data, a reasonable agreement between the two is found. It is concluded that the presented model can be used to study the hydrodynamical aspects of the fluid flow in a flat plate hemodialyzer.

Effect of nano-particles on MHD flow of tangent hyperbolic fluid in a ciliated tube: an application to fallopian tube

This study shows the effects of magnetic field and copper nanoparticles on the flow of tangent hyperbolic fluid (blood) through a ciliated tube (fallopian tube). The present study will be very helpful for those patients who are facing blood clotting in fallopian tube that may cause for infertility or cancer. The nanoparticles and magnetic field are very helpful to break the clots in blood flowing in fallopian tube. Since blood flows in fallopian tube due to ciliary movement, therefore medicines containing copper nanoparticles and magnetic field with radiation therapy help to improve the patient. Ciliary movement has a particular pattern of motion i.e., metachronal wavy motion which helps to fluid flow. For the forced convective MHD flow of tangent hyperbolic nano-fluid, momentum and energy equations are solved by the small Reynolds' number approximation and Adomian decomposition method by constructing the recursive relation of ADM and solved by software "MATHEMATICA". The effects of parameters such as nanoparticle volume fraction, Hartmann number, entropy generation and Bejan's number have been discussed through graphs plotted in software "MATHEMATICA". It is found that blood flow is accelerated and heat transfer enhancement is maximum in the presence of nano particles, also magnetic effects accelerates the blood flow and help to enhance the heat transfer whereas the presence of porous medium increases the fluid's velocity and reduce the transfer of heat through fluid flow.

Analysis of a self-propelling sheet with heat transfer through non-isothermal fluid in an inclined human cervical canal

The present theoretical analysis deals with biomechanics of the self-propulsion of a swimming sheet with heat transfer through non-isothermal fluid filling an inclined human cervical canal. Partial differential equations arising from the mathematical modeling of the proposed model are solved analytically. Flow variables like pressure gradient, propulsive velocity, fluid velocity, time mean flow rate, fluid temperature, and heat-transfer coefficients are analyzed for the pertinent parameters. Striking features of the pumping characteristics are explored. Propulsive velocity of the swimming sheet becomes faster for lower Froude number, higher Reynolds number, and for a vertical channel. Temperature and peak value of the heat-transfer coefficients below the swimming sheet showed an increase by the increment of Brinkmann number, inclination, pressure difference over wavelength, and Reynolds number whereas these quantities decrease with increasing Froude number. Aforesaid parameters have shown opposite effects on the peak value of the heat-transfer coefficients below and above the swimming sheet. Relevance of the current results to the spermatozoa transport with heat transfer through non-isothermal cervical mucus filling an inclined human cervical canal is also explored.

Antisense against Amyloid-β Protein Precursor Reverses Memory Deficits and Alters Gene Expression in Neurotropic and Insulin-Signaling Pathways in SAMP8 Mice

The senescence-accelerated mouse (SAMP8) strain exhibits an age-related decrease in memory accompanied by an increase in hippocampal amyloid-β protein precursor (AβPP) and amyloid-β peptide (Aβ). We have shown that administration of an antisense oligonucleotide against the Aβ region of AβPP (AβPP antisense) reverses the memory deficits. The purpose of this study was to determine the effect of peripheral (IV) administration of AβPP antisense on hippocampal gene expression. The AβPP antisense reversed the memory deficits and altered expression of 944 hippocampal genes. Pathway analysis showed significant gene expression changes in nine pathways. These include the MAPK signaling pathway (p = 0.0078) and the phosphatidylinositol signaling pathway (p = 0.043), which we have previously shown to be altered in SAMP8 mice. The changes in these pathways contributed to significant changes in the neurotropin (p = 0.0083) and insulin signaling (p = 0.015) pathways, which are known to be important in learning and memory. Changes in these pathways were accompanied by phosphorylation changes in the downstream target proteins p70S6K, GSK3β, ERK, and CREB. These changes in hippocampal gene expression and protein phosphorylation may suggest specific new targets for antisense therapy aimed at improving memory.

The present and future disease burden of hepatitis C virus infections with today's treatment paradigm - volume 3

The total number, morbidity and mortality attributed to viraemic hepatitis C virus (HCV) infections change over time making it difficult to compare reported estimates from different years. Models were developed for 15 countries to quantify and characterize the viraemic population and forecast the changes in the infected population and the corresponding disease burden from 2014 to 2030. With the exception of Iceland, Iran, Latvia and Pakistan, the total number of viraemic HCV infections is expected to decline from 2014 to 2030, but the associated morbidity and mortality are expected to increase in all countries except for Japan and South Korea. In the latter two countries, mortality due to an ageing population will drive down prevalence, morbidity and mortality. On the other hand, both countries have already experienced a rapid increase in HCV-related mortality and morbidity. HCV-related morbidity and mortality are projected to increase between 2014 and 2030 in all other countries as result of an ageing HCV-infected population. Thus, although the total number of HCV countries is expected to decline in most countries studied, the associated disease burden is expected to increase. The current treatment paradigm is inadequate if large reductions in HCV-related morbidity and mortality are to be achieved.

Strategies to manage hepatitis C virus infection disease burden - volume 3

The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 15 countries in Europe, the Middle East and Asia, and the relative impact of two scenarios was considered: increased treatment efficacy while holding the annual number of treated patients constant and increased treatment efficacy and an increased annual number of treated patients. Increasing levels of diagnosis and treatment, in combination with improved treatment efficacy, were critical for achieving substantial reductions in disease burden. A 90% reduction in total HCV infections within 15 years is feasible in most countries studied, but it required a coordinated effort to introduce harm reduction programmes to reduce new infections, screening to identify those already infected and treatment with high cure rate therapies. This suggests that increased capacity for screening and treatment will be critical in many countries. Birth cohort screening is a helpful tool for maximizing resources. Among European countries, the majority of patients were born between 1940 and 1985. A wider range of birth cohorts was seen in the Middle East and Asia (between 1925 and 1995).

Historical epidemiology of hepatitis C virus (HCV) in select countries - volume 3

Detailed, country-specific epidemiological data are needed to characterize the burden of chronic hepatitis C virus (HCV) infection around the world. With new treatment options available, policy makers and public health officials must reconsider national strategies for infection control. In this study of 15 countries, published and unpublished data on HCV prevalence, viraemia, genotype, age and gender distribution, liver transplants and diagnosis and treatment rates were gathered from the literature and validated by expert consensus in each country. Viraemic prevalence in this study ranged from 0.2% in Iran and Lebanon to 4.2% in Pakistan. The largest viraemic populations were in Pakistan (7 001 000 cases) and Indonesia (3 187 000 cases). Injection drug use (IDU) and a historically unsafe blood supply were major risk factors in most countries. Diagnosis, treatment and liver transplant rates varied widely between countries. However, comparison across countries was difficult as the number of cases changes over time. Access to reliable data on measures such as these is critical for the development of future strategies to manage the disease burden.

SAMP8 mice have altered hippocampal gene expression in long term potentiation, phosphatidylinositol signaling, and endocytosis pathways

The senescence-accelerated mouse (SAMP8) strain exhibits decreased learning and memory and increased amyloid beta (Aβ) peptide accumulation at 12 months. To detect differences in gene expression in SAMP8 mice, we used a control mouse that was a 50% cross between SAMP8 and CD-1 mice and which showed no memory deficits (50% SAMs). We then compared gene expression in the hippocampus of 4- and 12-month-old SAMP8 and control mice using Affymetrix gene arrays. At 12 months, but not at 4 months, pathway analysis revealed significant differences in the long term potentiation (6 genes), phosphatidylinositol signaling (6 genes), and endocytosis (10 genes) pathways. The changes in long term potentiation included mitogen-activated protein kinase (MAPK) signaling (N-ras, cAMP responsive element binding protein [CREB], protein phosphatase inhibitor 1) and Ca-dependent signaling (inositol triphosphate [ITP] receptors 1 and 2 and phospholipase C). Changes in phosphatidylinositol signaling genes suggested altered signaling through phosphatidylinositol-3-kinase, and Western blotting revealed phosphorylation changes in serine/threonine protein kinase AKT and 70S6K. Changes in the endocytosis pathway involved genes related to clathrin-mediated endocytosis (dynamin and clathrin). Endocytosis is required for receptor recycling, is involved in Aβ metabolism, and is regulated by phosphatidylinositol signaling. In summary, these studies demonstrate altered gene expression in 3 SAMP8 hippocampal pathways associated with memory formation and consolidation. These pathways might provide new therapeutic targets in addition to targeting Aβ metabolism itself.

Morphine modulation of thrombospondin levels in astrocytes and its implications for neurite outgrowth and synapse formation

Opioid receptor signaling via EGF receptor (EGFR) transactivation and ERK/MAPK phosphorylation initiates diverse cellular responses that are cell type-dependent. In astrocytes, multiple μ opioid receptor-mediated mechanisms of ERK activation exist that are temporally distinctive and feature different outcomes. Upon discovering that chronic opiate treatment of rats down-regulates thrombospondin 1 (TSP1) expression in the nucleus accumbens and cortex, we investigated the mechanism of action of this modulation in astrocytes. TSP1 is synthesized in astrocytes and is released into the extracellular matrix where it is known to play a role in synapse formation and neurite outgrowth. Acute morphine (hours) reduced TSP1 levels in astrocytes. Chronic (days) opioids repressed TSP1 gene expression and reduced its protein levels by μ opioid receptor and ERK-dependent mechanisms in astrocytes. Morphine also depleted TSP1 levels stimulated by TGFβ1 and abolished ERK activation induced by this factor. Chronic morphine treatment of astrocyte-neuron co-cultures reduced neurite outgrowth and synapse formation. Therefore, inhibitory actions of morphine were detected after both acute and chronic treatments. An acute mechanism of morphine signaling to ERK that entails depletion of TSP1 levels was suggested by inhibition of morphine activation of ERK by a function-blocking TSP1 antibody. This raises the novel possibility that acute morphine uses TSP1 as a source of EGF-like ligands to activate EGFR. Chronic morphine inhibition of TSP1 is reminiscent of the negative effect of μ opioids on EGFR-induced astrocyte proliferation via a phospho-ERK feedback inhibition mechanism. Both of these variations of classical EGFR transactivation may enable opiates to diminish neurite outgrowth and synapse formation.

Ectromelia virus infections of mice as a model to support the licensure of anti-orthopoxvirus therapeutics

The absence of herd immunity to orthopoxviruses and the concern that variola or monkeypox viruses could be used for bioterroristic activities has stimulated the development of therapeutics and safer prophylactics. One major limitation in this process is the lack of accessible human orthopoxvirus infections for clinical efficacy trials; however, drug licensure can be based on orthopoxvirus animal challenge models as described in the "Animal Efficacy Rule". One such challenge model uses ectromelia virus, an orthopoxvirus, whose natural host is the mouse and is the etiological agent of mousepox. The genetic similarity of ectromelia virus to variola and monkeypox viruses, the common features of the resulting disease, and the convenience of the mouse as a laboratory animal underscores its utility in the study of orthopoxvirus pathogenesis and in the development of therapeutics and prophylactics. In this review we outline how mousepox has been used as a model for smallpox. We also discuss mousepox in the context of mouse strain, route of infection, infectious dose, disease progression, and recovery from infection.

Knowledge, attitudes and practices regarding tuberculosis in two districts of Punjab, Pakistan

SETTING

Pakistan ranks eighth among the world's highest tuberculosis (TB) burden countries, and Punjab province accounts for 60% of TB cases nationally.

OBJECTIVE

To explore knowledge, attitudes and practices regarding TB in the general population of two districts of Punjab province, and the effect of socio-economic determinants.

DESIGN

In a cross-sectional survey, subjects aged > or =20 years were randomly selected using multistage cluster sampling and interviewed. A knowledge score was formulated based on nine questions. Bivariate analysis using the chi(2) test was employed to independently correlate socio-economic factors with understanding of disease and information sources. Attitudes, practices and information sources were also compared with TB knowledge.

RESULTS

Forty-two per cent of the surveyed population had good knowledge about TB, which was associated with better education, high income and good housing (all P < 0.001). Despite the fact that the majority (82.2%) knew about correct treatment, less than half (48.8%) were aware that diagnosis and treatment were free. Intended health-seeking behaviour was determined by better education (P = 0.011), good housing (P = 0.004) and good knowledge about TB (P < 0.001). Television (69.4%) and health workers (43.6%) were the main sources of information.

CONCLUSION

Socio-economic factors should be considered when designing communication strategies and prioritising TB prevention and control interventions.

Generation of <7 fs pulses at 800 nm from a blue-pumped optical parametric amplifier at degeneracy

We generate ultrabroadband pulses at 800 nm from an optical parametric amplifier (OPA) pumped by the second harmonic of a Ti:sapphire system and working at degeneracy. The OPA is seeded by a white-light continuum generated from a near-IR OPA pumped by the same laser. Nearly transform-limited <7 fs pulses, fully characterized in amplitude and phase, are obtained with a chirped mirror compressor. The system fills the gap around 800 nm for broadband continuum seeded OPAs pumped by Ti:sapphire-based sources.

Regulation of the Drosophila Enhancer of split and invected-engrailed gene complexes by sister chromatid cohesion proteins

The cohesin protein complex was first recognized for holding sister chromatids together and ensuring proper chromosome segregation. Cohesin also regulates gene expression, but the mechanisms are unknown. Cohesin associates preferentially with active genes, and is generally absent from regions in which histone H3 is methylated by the Enhancer of zeste [E(z)] Polycomb group silencing protein. Here we show that transcription is hypersensitive to cohesin levels in two exceptional cases where cohesin and the E(z)-mediated histone methylation simultaneously coat the entire Enhancer of split and invected-engrailed gene complexes in cells derived from Drosophila central nervous system. These gene complexes are modestly transcribed, and produce seven of the twelve transcripts that increase the most with cohesin knockdown genome-wide. Cohesin mutations alter eye development in the same manner as increased Enhancer of split activity, suggesting that similar regulation occurs in vivo. We propose that cohesin helps restrain transcription of these gene complexes, and that deregulation of similarly cohesin-hypersensitive genes may underlie developmental deficits in Cornelia de Lange syndrome.

Mousepox in the C57BL/6 strain provides an improved model for evaluating anti-poxvirus therapies

The intranasal lethal mousepox model employing the A/Ncr mouse strain is used to evaluate anti-orthopoxvirus therapies. These infections mimic large droplet transmission and result in 100% mortality within 7-10 days with as little as 1 PFU of ectromelia virus. Unlike the A/Ncr model, humans are less susceptible to lethal respiratory infections with variola virus and monkeypox virus as demonstrated by their lower mortality rates. In this study we show that a low dose intranasal infection of C57BL/6 mice results in 60-80% mortality and better models smallpox. Comparing CMX001 (HDP-cidofovir) efficacy in the A/Ncr strain and the C57BL/6 strain revealed that delayed treatment with CMX001 is more efficacious at preventing severe disease in the C57BL/6 strain. The increased efficacy of CMX001 in C57BL/6 over A/Ncr following an intranasal infection with ectromelia appears to be mediated by a stronger Th1 cell mediated response. Following footpad infection we show that the C57BL/6 strain has earlier and more robust transcriptional activity, Th1 cytokine secretions, antigen presenting activity and IFNγ splenic CD8+ T cell responses as compared to the A/Ncr strain. As a result of the enhanced immune response in the C57BL/6 strain, non-lethal intradermal ectromelia infections can therapeutically protect up to 3 days following a homologous, lethal intranasal infection – much like how smallpox vaccination can protect humans for up to 4 days following intranasal variola infection.

In vitro monitoring of rabbit anterior cruciate ligament damage by acoustic emission

Anterior cruciate ligament (ACL) rupture is a major clinical problem leading to instability and degeneration of the knee joint. The problem is compounded by the limited ability of the ACL to heal when ruptured. The existing knowledge regarding the way the ACL ruptures is limited, and this investigation is an attempt to understand the nature of the ruptures using the rabbit as a model. A total of 16 rabbit tibia-ACL-femur complexes were stretched in tension to complete rupture. Four specimens were stretched to failure at a displacement rate of 0.5 mm/min and 12 specimens at 10 mm/min. Acoustic emission (AE) transducers were placed on both the tibia and the femur, and stress wave signals generated during the tensile test were recorded. Fibre fractures produced the highest amplitude signals with a relatively longer rise time. Other failure modes such as matrix failure and debonding produced lower amplitude signals with shorter rise times. We also noted that few events were recorded during the initial period of tensile loading (the elastic phase). The activity then increased significantly after maximum load was reached. The location information provided by the acoustic emission system was consistent with the final site of rupture. We have shown that AE can be used to characterise ligament damage, with fibre pull-outs and fibre fracture producing the highest signal amplitudes.

The use of expandable metallic stents for acute tracheal stenosis in the growing lamb

PURPOSE

Expandable metallic stents (Palmaz stents) have been used in the treatment of tracheobronchial obstruction in children and adults. The authors investigated their utility in the management of acute airway stenosis in a growing animal model.

METHODS

A model for tracheal stenosis was developed in young lambs (mean age, 4 weeks; mean weight, 8.6 kg). Via an anterior tracheotomy, a circumferential mucosal injury to the trachea was produced with electrocautery in 31 lambs. In the control group (n = 10) no further intervention was used. In the treatment groups, either serial balloon dilatation of the stricture was performed (n = 6), or expandable metallic stents were inserted across the stricture (n = 15). All animals were monitored daily for signs of respiratory distress. Body weights, fluoroscopic airway measurements and rigid bronchoscopy were performed at least weekly.

RESULTS

The average weekly rate of airway growth was 8.2% +/- 5.5% of the tracheal cross-sectional area (CSA). All animals displayed severe stenosis (mean, 90.2% +/- 7.5% of CSA) within 13.1 +/- 4 days after the injury. All animals in the control group had severe respiratory distress, weight loss and died within 14.6 +/- 2.8 days after injury. Serial balloon dilatation of the stricture alone failed to relieve symptoms in all six animals in this group, who died within 20 +/- 1 days after the injury, despite two to three dilatations each. With placement of expandable metallic stents, only 3 of 15 lambs died (two of pneumonia, one of iatrogenic perforation). The remaining 12 remained symptom-free and gained weight during a 2-month follow-up period. However, fluoroscopic examination showed partial collapse of the stents in all of these animals (mean, 44.7% +/- 21.6% of CSA) requiring an average of 2 +/- 0.7 bronchoscopic dilatations. Pathological evaluation showed more pronounced granulation tissue in the stented animals.

CONCLUSIONS

The authors conclude that expandable metallic stents provide an effective tool in the management of acute tracheal stenosis. However, airway growth, tissue reaction, and the mechanical properties of the stent require close monitoring and stent adjustment.

Insulin-like growth factor-I gene expression in three models of accelerated lung growth

BACKGROUND/PURPOSE

We have learned previously that in utero tracheal ligation reverses the structural and physiological effects of surgically created congenital diaphragmatic hernia. In addition, we have discovered that postnatal lung growth similarly can be accelerated using liquid-based airway distension with perfluorocarbon. Another model of accelerated lung growth is that of compensatory growth seen after neonatal pneumonectomy. In all of these models, growth has occurred because of an increase in alveolar number rather than enlargement of preexisting alveoli. However, the molecular mechanisms underlying these processes remain unknown. The purpose of this study was to determine if gene expression could be altered by changes in physical forces in the prenatal and postnatal lung.

METHODS

The three models of accelerated lung growth studied were the following: (1) The prenatal group, consisted of fetal lambs (n = 12) that underwent the surgical creation of a left diaphragmatic hernia at 90 days' gestation. Six of these animals also underwent simultaneous tracheal ligation. (2) The PFC group consisted of five neonatal animals that underwent isolation of the superior segment of the right upper lobe, with intrabronchial distension with perfluorocarbon to 7 to 10 mm Hg pressure for a 3-week period. (3) The postpneumonectomy group consisted of four neonatal animals that underwent left pneumonectomy. In the fetal study, lungs were retrieved at term (130 days), and in the postnatal study, lungs were retrieved 3 weeks after initial intervention. In all cases, RNA was extracted from snap-frozen lung samples and Northern blot analysis performed.

RESULTS

Insulinlike growth factor-I, insulinlike growth factor-II, and vascular endothelial growth factor gene expression were analyzed by densitometry. Insulinlike growth factor-I gene expression was found to be decreased in association with experimental diaphragmatic hernia (P = .005), but restored to normal with tracheal ligation. Insulinlike growth factor-I gene expression was significantly increased in both postnatal models of accelerated lung growth (P = .022, P = .016). No significant differences were found in insulinlike growth factor-II or vascular endothelial growth factor gene expression.

CONCLUSIONS

The authors conclude from these preliminary data that (1) insulin like growth factor-I gene expression is reduced in experimental fetal diaphragmatic hernia and restored to normal by tracheal ligation, and (2) insulinlike growth factor-I gene expression is increased in both the liquid-based airway distension and postpneumonectomy models of accelerated postnatal lung growth. The authors speculate that all of these manipulations exploit a natural pathway essential for normal lung growth.

Long-term effect of perfluorocarbon distension on the lung

BACKGROUND/PURPOSE

We have demonstrated previously that postnatal lung growth can be accelerated by continuous intrapulmonary distension with perfluorocarbon (PFC). The purpose of this study was to examine the effect of PFC distension on long-term lung function and to determine if shorter periods of lung distension would be sufficient to stimulate growth.

METHODS

Eight neonatal lambs underwent a right thoracotomy. The superior segment of the right upper lobe of the experimental group (n = 5) was isolated and distended with PFC to an intrabronchial pressure of 7 to 10 mm Hg. The inferior segment was removed. After a 7-day distension period (the maximum period of exposure currently allowed for humans), the experimental animals underwent removal of the intrabronchial catheter and surgical closure of the bronchial stump. Control animals (n = 3) underwent right upper lobe inferior segmentectomy alone. Animals were allowed to breathe spontaneously and reach 3 to 6 months of age. Before death, all animals were evaluated by chest radiographs and ventilation-perfusion scans. Pulmonary venous blood gas levels were obtained. Lungs were harvested and airway fixed for morphometric analysis.

RESULTS

Chest radiographs of the experimental group showed variable amounts of intrapleural and interstitial PFC but were otherwise normal. Results of ventilation/perfusion (VQ) scans of all experimental animals were normal. On retrieval, the right upper lobe of experimental animals appeared slightly hyperinflated compared with controls. Right upper lobe pulmonary vein PaO2 to left pulmonary vein PaO2 ratio was comparable in experimental and control animals (1.2 +/- .41 v 0.92 +/- .15). DNA to protein ratios were slightly higher in the right upper lobes of experimental animals, however, the difference was not statistically significant (.64 +/- .11 v .42 +/- .03). On histological evaluation, the airway epithelium and alveoli of the right upper lobe of experimental animals appeared normal. Lung morphometry results showed no statistically significant differences in alveolar number between experimental and control animals.

CONCLUSIONS

From these preliminary data we conclude that (1) lung architecture is preserved in juvenile animals subjected to intrapulmonary PFC distension as neonates, (2) lung function is preserved in the lobar segment after PFC distension, and (3) intrapulmonary PFC distension appears to be safe at 3 to 6 months follow-up. However, 7 days of PFC distension is insufficient to promote lung growth.

Enteric duplications of the pancreatic head: definitive management by local resection

BACKGROUND/PURPOSE

Enteric duplications can occur throughout the entire alimentary tract. When they occur in the pancreatic head, they present a formidable challenge in both diagnosis and treatment. Surgical management has ranged from simple drainage to local excision or radical resection (eg, Whipple procedure). The authors propose that with identification of the local anatomic relationships, definitive management can be achieved by complete local resection of the cyst mucosa.

METHODS

The authors have treated four patients, ages 13 months to 4 years for enteric duplication cysts within the pancreatic head.

RESULTS

Clinical presentations were quite varied, including pancreatitis (n = 2), gastritis (secondary to increased production of gastrin), and recurrent pleural effusion with high amylase content. Two of the four cysts had been drained initially using Roux-en-Y cystenterostomies. Our preoperative imaging studies included abdominal ultrasonography, endoscopic retrograde cholangiopancreatography (ERCP), angiography, computerized tomography (CT) or magnetic resonance imaging (MRI) scanning. When necessary intraoperatively, ultrasonography was used for cyst localization and transduodenal pancreatography to define precise ductal relationships. All four duplication cysts were completely excised, including two that communicated directly with the main pancreatic duct. One of the latter extended into the pleural cavity and required a thoracotomy for complete excision. Pathological exam of the excised cysts demonstrated gastric, duodenal, or respiratory mucosa. All four patients have remained entirely asymptomatic during a follow-up of 2 to 7 years postoperatively.

CONCLUSION

The authors conclude that complete local resection of enteric duplication cysts in the pancreatic head can be performed for definitive management, avoiding the complications of more radical procedures.

Bcl-2 expression in Langerhans' cell histiocytosis

Langerhans' cell histiocytosis (LCH) is an abnormal accumulation of dendritic histiocytes of unknown pathogenesis. It has recently been shown to be a clonal process. Bcl-2 is a proto-oncogene whose protein product is known to inhibit apoptosis. The overexpression of bcl-2 has been demonstrated in a number of neoplasms, presumably prolonging the survival of the neoplastic cells. We examined the expression of bcl-2 in normal Langerhans' cells in the skin and in LCH by immunohistochemistry for protein and in situ hybridization for mRNA to see if it could be implicated in the pathogenesis of this disorder. Additionally, we performed Southern analysis to determine if genomic rearrangement of the bcl-2 gene occurs in cases of LCH. Bcl-2 was not detected in normal skin Langerhans' cells. Eleven of thirteen cases of LCH demonstrated bcl-2 protein expression in the cytoplasm of the Langerhans' cells by immunohistochemistry, while 12 of 13 cases had evidence of bcl-2 mRNA by in situ hybridization. Southern analysis revealed a germline configuration of the bcl-2 gene in the five cases studied. These findings suggest that bcl-2 expression is present and up-regulated in pathologic Langerhans' cells, however, this overexpression does not appear to be due to genomic rearrangement.

Breakpoint cluster region, immunoglobulin, and T-cell receptor gene rearrangement analysis in juvenile chronic myelogenous leukemia

Juvenile chronic myelogenous leukemia (JCML) is a heterogeneous disorder composed of Philadelphia chromosome-positive (Ph+) CML, which is similar to CML in adults, and Ph-negative (Ph-) CML, a childhood myelodysplasia resembling chronic myelomonocytic leukemia in adults. These two disorders are not always readily separable by leukocyte alkaline phosphatase (LAP) scoring and by karyotyping, yet they have different courses and outcomes. We compared the results of breakpoint cluster region (bcr) gene rearrangement analysis with LAP score and karyotype in these patients. In addition, analysis for immunoglobulin and T-cell receptor gene rearrangement was done to investigate the possibility of mixed myeloid and lymphoid lineage, which has been shown to occur in childhood acute myelogenous leukemia and CML in blast crisis. Peripheral blood and bone marrow samples from six patients with JCML aged 5 to 19 yr were analyzed. One case was Ph+, and five were Ph- by karyotyping. Two samples showed LAP scores of 5 and 11 (one Ph+ and one Ph-); others were normal. All were digested with EcoRI, HindIII, and BamHI for immunoglobulin heavy and light chains and T-cell receptor beta-chain analysis and, in addition, with BglII for bcr analysis. Samples were hybridized with probes to JH, JK, CT beta, and bcr (Oncor). A bcr rearrangement was shown in the Ph+ sample; all others, including one with a very low LAP score, were negative. No JH, JK, or CT beta rearrangements were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood conservation and autotransfusion in cardiac surgery

Blood conservation techniques of withdrawal of blood just before surgery, intraoperative blood salvage with Solcotrans (Solco Basle [UK] Ltd.), and profound hemodilution were used in 14 patients undergoing open heart surgery (group I) and compared with equally matched 14 patients who had profound hemodilution only during cardiopulmonary bypass (CPB) and acted as controls (group II). Group I patients required a mean of 255 mL of homologous blood per patient to achieve a target hemoglobin of 8 g/dL compared to group II patients who required a mean of 1,011 mL per patient (p = 0.0001). By using autologous blood there was a marked reduction in homologous blood exposure. Eight patients in group I and two patients in group II required no homologous blood. No adverse events occurred. In the process of conservation of blood in open heart surgery, we found the combination of the above techniques used in Group I patients to be safe and effective.

Alterations in hepatic microsomal mixed-function oxidase system during different levels of food restriction in adult male and female rats

Wistar strain adult male and female rats were given 25, 50 and 75% less food than an ad libitum-fed group of rats for 45 d and the effects of food restriction on hepatic drug metabolizing enzymes, microsomal electron transport components, NADPH-dependent lipid peroxidation and glutathione-S-transferase activities were studied. Compared to ad libitum-fed controls, the cytochrome P-450 levels were higher in food restricted male rats, while they were lower in food restricted females. The activities of NADPH cytochrome c reductase were lower in food restricted females than in ad libitum-fed controls. The activities of drug metabolizing enzymes, aminopyrine N-demethylase and acetanilide hydroxylase were higher in food restricted males, whereas in food restricted females these activities were lower than in respective groups fed ad libitum. Microsomal, NADPH-dependent lipid peroxidation was higher in 25 and 50% food restricted females while in 50 and 75% food restricted males it was lower than in ad libitum controls of the same sex. The cytosolic glutathione-S-transferase activities were lower in food restricted rats of both the sexes than in the same sexed controls. Another group of male and female rats were given 75% less food than the ad libitum-fed rats and refed for 3 d prior to killing. Here also, the effects of restriction were different between sexes. It is concluded that hepatic microsomal mixed-function oxidase system (MFOS) is altered due to feed restriction and food restriction followed by refeeding, in a sex-related manner.

Effect of ampicillin on hepatic microsomal mixed-function oxidase system in male mice

The effect of ampicillin [(D)-alpha-aminobenzyl penicillin] administration on the hepatic mixed-function oxidase (MFO) system was studied in male mice. Ampicillin (100 mg/kg, i.p., 3 days) decreased the levels of cytochrome P-450, aminopyrine N-demethylase, acetanilide hydroxylase and cytochrome c-reductase activity significantly. In carbon tetrachloride (CCl4)-pretreated mice, ampicillin increased acetanilide hydroxylation compared with CCl4 treatment alone; however, all other parameters of the MFO system remained unchanged. Ampicillin exhibited type II binding with microsomes (trough at 388 nm, peak at 430 nm). Thus ampicillin acts as an inhibitor of the MFO system.