Antibody-drug conjugate as targeted therapeutics against hepatocellular carcinoma: preclinical studies and clinical relevance

An antibody-drug conjugate (ADC) is an advanced chemotherapeutic option with immense promises in treating many tumor. They are designed to selectively attack and kill neoplastic cells with minimal toxicity to normal tissues. ADCs are complex engineered immunoconjugates that comprise a monoclonal antibody for site-directed delivery and cytotoxic payload for targeted destruction of malignant cells. Therefore, it enables the reduction of off-target toxicities and enhances the therapeutic index of the drug. Hepatocellular carcinoma (HCC) is a solid tumor that shows high heterogeneity of molecular phenotypes and is considered the second most common cause of cancer-related death. Studies show enormous potential for ADCs targeting GPC3 and CD24 and other tumor-associated antigens in HCC with their high, selective expression and show potential outputs in preclinical evaluations. The review mainly highlights the preclinical evaluation of different antigen-targeted ADCs such as MetFab-DOX, Anti-c-Met IgG-OXA, Anti CD 24, ANC-HN-01, G7mab-DOX, hYP7-DCand hYP7-PC, Anti-CD147 ILs-DOX and AC133-vcMMAF against hepatocellular carcinoma and its future relevance.

Unusual causes of fungal rhinosinusitis: a study from a tertiary care centre in South India

PURPOSE

The frequency of mycotic infections of the nose and paranasal sinuses has been increasing over the past three decades. Apart from the common causes of fungal rhinosinusitis such as Aspergillus species and Penicillium species, there have been reports of rare and unusual fungi isolated from India and other countries.

OBJECTIVE

The objective of this study is to find out the prevalence of fungal infections of the nose and paranasal sinuses caused by unusual fungal isolates at a tertiary care teaching hospital in South India.

MATERIALS AND METHODS

Duration of the study period was from April 2009 to March 2010. Specimens were collected from the nose and paranasal sinuses of all clinically and radiologically diagnosed cases of rhinosinusitis. All the clinical specimens were processed by standard methods for fungal culture. This included initial screening by 10% potassium hydroxide, inoculation of the specimen onto Sabouraud dextrose agar and incubation at 25°C and 37°C, followed by slide culture and other special techniques wherever necessary. Histopathological examination was also performed for the specimens.

RESULTS

A total of 60 specimens were received for fungal culture from cases of rhinosinusitis during the period, out of which 45 showed no growth. There were nine cases of Aspergillus flavus, 1 each of Aspergillus fumigatus and Penicillium species. The rest four specimens grew rare fungal isolates, i.e. Acremonium sp., Scedosporium apiospermun, Cladosporium cladosporioides and Lasiodiplodia theobromae. Histopathological findings were also positive for these four cases.

CONCLUSION

Apart from the common causes, unusual fungal pathogens were isolated from cases of rhinosinusitis during the study period, which is in accordance with similar reports from other parts of India and some other countries.

Impact of nutrition education on knowledge and haemoglobin status of hill women in Uttarakhand State of India

INTRODUCTION

This study aimed to examine the impact of the use of single vs. combination of media on nutritional knowledge and haemoglobin status of women in a rural hill area in Uttarakhand State, India.

METHODS

Women from three villages were selected randomly and divided into three groups namely, print media group (n = 59), multimedia group (n = 53) and control group (n = 111). The print media group was exposed to nutrition education through the use of calendars on anaemia for 60 days; the multimedia group was given nutrition education through a combination of media including calendars, video films, and group discussions for 60 days.

RESULTS

At pre-exposure stage, 62.7% of the women in the print media group, 67.9% of the multimedia group, and 66.7% of the control group had a low nutrition knowledge level. After exposure, the print media group and the multimedia group showed a significant rise in nutrition knowledge, with the multimedia group scoring significantly higher than the print media group. Overall, 69.1% of the women were anaemic with mean haemoglobin concentration of 10.74 +/- 0.86 g/dl. A non-significant rise in mean haemoglobin concentrations in the experimental groups was found at post-exposure stage.

CONCLUSION

Calendars and video films are effective in increasing nutrition knowledge of illiterate hill women. Use of mass media programmes of longer duration should be encouraged to combat the nutritional problems of rural communities.

Assessment of correlation between CT angiographic clot load score, pulmonary perfusion defect score and global right ventricular function with dual-source CT for acute pulmonary embolism

OBJECTIVE

The purpose of this study was to prospectively investigate the correlation between CT angiographic clot load (CTACL) score, pulmonary perfusion defect (PPD) score and the global right ventricular function in the assessment of pulmonary embolism (PE) severity.

METHODS

49 patients with acute PE, who underwent dual-source CT scan, were included in the study. CT angiography and perfusion imaging were performed. Data from electrocardiogram-gated coronary angiography scanning protocol were used for right ventricular function analysis. Two readers evaluated the CTACL and PPD scores using the Qanadli and Chae methods, respectively.

RESULTS

The PPD score had a strong positive correlation with the CTACL score (r=0.72, p<0.001) and both scores in turn had a strong positive correlation with the right ventricular/left ventricular (RV/LV) diameter ratio (r=0.60, r=0.62, p<0.001). However, the PPD score had a strong negative correlation with ejection fraction (EF) (r=-0.63, p<0.001) while the CTACL score had a low negative correlation with EF (r=-0.33, p=0.02). Between the RV/LV<1 group (n=35) and the RV/LV >1 group (n=14), the PPD score, CTACL score, pulmonary artery trunk diameter, EF and reflux of inferior vena cava were significantly different, all with p<0.001. The end-systolic volume (p=0.01) was significantly different but the end-diastolic volume (p=0.11) and stroke volume (p=0.08) showed no statistically significant difference between the two groups.

CONCLUSION

Therefore, considering PPD scores, CTACL scores and cardiovascular manifestations together may be helpful in the evaluation of PE severity.

Simultaneous pedicled flaps for coverage of complex blast injuries to the forearm and hand (with supplemental external fixation to the iliac crest for immobilization)

The technique of two simultaneous pedicled flaps to a single extremity has recently proven useful in the care of war-injured military personnel. We present two cases of combat-injured Marines who underwent upper extremity reconstruction using simultaneous pedicled flaps. These cases illustrate a simple and successful alternative to free tissue transfer in providing coverage to complex soft tissue defects of the hand and forearm. Good outcomes were obtained in circumstances where free tissue transfer was not indicated.

Fatal cellulitis caused by Apophysomyces elegans

A case of cellulitis of the left lateral side of the face caused by the zygomycete Apophysomyces elegans in a healthy male following a road traffic accident is reported. The contaminated soil was the source of fungus. Broad aseptate fungal hyphae were seen in the necrosed tissues. Extensive tissue debridement and treatment with amphotericin B were not successful in controlling the rapid invasion of the tissues by the fungus. Patient developed angioinvasion, severe cellulitis and finally succumbed to the infection three weeks after admission.

Biofilm formation by a biotechnologically important tropical marine yeast isolate, Yarrowia lipolytica NCIM 3589

Biofilm formation by Yarrowia lipolytica, a biotechnologically important fungus in microtitre plates, on glass slide surfaces and in flow cell was investigated. In microtitre plates, there was a short lag phase of adhesion followed by a period of rapid biofilm growth. The fungus formed extensive biofilms on glass slides, whereas in flow-cells a multicellular, three-dimensional microcolony structure was observed. The isolate formed biofilms in seawater and in fresh water media at neutral pH when grown in microtitre plates. The carbon sources differentially affected formation of biofilms in microtitre plates. Lactic acid, erythritol, glycerol, glucose and edible oils supported the formation of biofilms, while alkanes resulted in sub-optimal biofilm development. A variation in the morphology of the fungus was observed with different carbon sources. The results point to the possible existence of highly structured biofilms in varied ecological niches from where the yeast is isolated.

Biofilm formation by a biotechnologically important tropical marine yeast isolate, Yarrowia lipolytica NCIM 3589

Biofilm formation by Yarrowia lipolytica, a biotechnologically important fungus in microtitre plates, on glass slide surfaces and in flow cell was investigated. In microtitre plates, there was a short lag phase of adhesion followed by a period of rapid biofilm growth. The fungus formed extensive biofilms on glass slides, whereas in flow-cells a multicellular, three-dimensional microcolony structure was observed. The isolate formed biofilms in seawater and in fresh water media at neutral pH when grown in microtitre plates. The carbon sources differentially affected formation of biofilms in microtitre plates. Lactic acid, erythritol, glycerol, glucose and edible oils supported the formation of biofilms, while alkanes resulted in sub-optimal biofilm development. A variation in the morphology of the fungus was observed with different carbon sources. The results point to the possible existence of highly structured biofilms in varied ecological niches from where the yeast is isolated.

Familial truncus arteriosus: a possible autosomal-recessive trait

Truncus arteriosus is a relatively uncommon congenital malformation. It accounts for approximately 1% of congenital heart diseases. The defect occurs sporadically but 22q11 deletion is frequently noted in such patients with conotruncal defects. We studied six cases of TA in four closely related families. Analysis of karyotypes in these cases was normal. Family 1 has one affected male infant who was born in 1998. Family 2 has two affected children (one male and one female) who were born in 1989 and 1995, respectively. They have four other normal children. Family 3 has two affected children (one male and one female) who were born in 1981 and 1984, respectively. They have three other normal children. Family 4 has one affected male born in 1998 and another healthy child. All parents of all affected children are double cousins. The data in this study are compatible with an autosomal-recessive inheritance, but multifactorial inheritance may also play a role.

Development of a large-scale biocalorimeter to monitor and control bioprocesses

Calorimetry has shown real potential at bench-scale for chemical and biochemical processes. The aim of this work was therefore to scale-up the system by adaptation of a standard commercially available 300-L pilot-scale bioreactor. To achieve this, all heat flows entering or leaving the bioreactor were identified and the necessary instrumentation implemented to enable on-line monitoring and dynamic heat balance estimation. Providing that the signals are sufficiently precise, such a heat balance would enable calculation of the heat released or taken up during an operational (bio)process. Two electrical Wattmeters were developed, the first for determination of the power consumption by the stirrer motor and the second for determination of the power released by an internal calibration heater. Experiments were designed to optimize the temperature controller of the bioreactor such that it was sufficiently rapid so as to enable the heat accumulation terms to be neglected. Further calibration experiments were designed to correlate the measured stirring power to frictional heat losses of the stirrer into the reaction mass. This allows the quantitative measurement of all background heat flows and the on-line quantitative calculation of the (bio)process power. Three test fermentations were then performed with B. sphaericus 1593M, a spore-forming bacterium pathogenic to mosquitoes. A first batch culture was performed on a complex medium, to enable optimization of the calorimeter system. A second batch culture, on defined medium containing three carbon sources, was used to show the fast, accurate response of the heat signal and the ability to perfectly monitor the different growth phases associated with growth on mixed substrates, in particular when carbon sources became depleted. A maximum heat output of 1100 W was measured at the end of the log-phase. A fed-batch culture on the same defined medium was then carried out with the feed rate controlled as a function of the calorimeter signal. A maximum heat output of 2250 W was measured at the end of the first log-phase. This work demonstrates that real-time quantitative calorimetry is not only possible at pilot-scale, but could be readily applied at even larger scales. The technique requires simple, readily available devices for determination of the few necessary heat flows, making it a robust, cost-effective technique for process development and routine monitoring and control of production processes.

Familial hypodigoxinemic membrane Na(+)-K(+) ATPase upregulatory syndrome - relation between digoxin status and cerebral dominance

A family with coexistence of hypotension, recurrent respiratory infection, motor tics, obsessive compulsive disorder, major depressive disorder, early onset osteoporosis, low body mass index, bulimia nervosa and healthy aging with longevity is described. The family members had hyposexual behavior, less tendency for spirituality, had no insomnia but a tendency towards increased somnolence, no addictive behaviour, had more bonding and affectionate behavior and were less creative with an average IQ. There was no vascular thrombosis, systemic neoplasm and neuronal degeneration in the index family. All members of the family were left hemispheric dominant. The level of serum digoxin, HMG CoA reductase activity and dolichol was found to be decreased in all with a corresponding increase in RBC Na(+)-K(+) ATPase activity and serum ubiquinone magnesium level. There was increase in tyrosine catabolites and a reduction in tryptophan catabolites in serum. Total and individual glycosaminoglycan fractions, carbohydrate residues of glycoproteins, glycolipids, activity of GAG degrading enzymes and glycohydrolases were decreased in serum. The concentration of RBC membrane total GAG and carbohydrate residues of glycoproteins increased while cholesterol : phospholipid ratio of membrane decreased. The activity of free radical scavenging enzymes were increased while the concentration of free radicals decreased significantly. The same biochemical patterns were observed in left hemispheric dominance as opposed to right hemispheric dominance. The significance of these findings in the pathogenesis of these disorders is discussed.

Inhibition of membrane Na+-K+ ATPase activity: a common pathway in central nervous system disorders

OBJECTIVES

The study was conducted to assess the role of hypothalamic digoxin in neuropsychiatric and systemic disorders. A hypothesis regarding the central role of hypothalamic digoxin in neuroimmunoendocrine integration is proposed.

METHODOLOGY

Blood samples from patients of CNS glioma, multiple sclerosis, systemic lupus erythematosis, subacute sclerosing panencephalitis, primary generalized epilepsy, Parkinson's disease, Down syndrome, AIDS dementia with neuropsychiatric features, syndrome X with multiple lacunar state, senile dementia, familial group (a family with familial coexistence of schizophrenia, Parkinson's disease, primary generalized epilepsy, malignant neoplasia, rheumatoid arthritis and syndrome X over three generations), schizophrenia and manic depressive psychosis were analysed for RBC membrane Na+-K+ ATPase, levels of digoxin and Mg++.

RESULTS

Inhibition of RBC membrane Na+-K+ ATPase activity was observed in most cases along with increase in the levels of serum digoxin and decrease in the level of serum Mg++.

CONCLUSION

The decreased Na+-K+ ATPase activity can be due to increased digoxin, which is a potent inhibitor of this enzyme. The inhibition of Na+-K+ ATPase can contribute to increase in intracellular calcium and decrease in magnesium, which can result in 1) defective neurotransmitter transport mechanism, 2) neuronal degeneration and apoptosis, 3) mitochondrial dysfunction, 4) defective golgi body function and protein processing dysfunction, 5) immune dysfunction and oncogenesis. The mechanism of how increased intracellular calcium and decreased magnesium can contribute to the above effects is discussed.

A hypothalamic digoxin mediated model for conscious and subliminal perception

The isoprenoid pathway and its metabolites--digoxin, dolichol and ubiquinone were assessed in schizophrenia. There was an upregulation of the isoprenoid pathway as evidenced by elevated HMG CoA reductase activity. Digoxin, an endogenous Na+-K+ ATPase inhibitor secreted by the hypothalamus was found to be elevated and RBC membrane Na+-K+ ATPase activity was found to be reduced in schizophrenia. Membrane Na+-K+ ATPase inhibition can result in increased intracellular Ca2+ and reduced magnesium levels. Hypothalamic digoxin can modulate conscious and subliminal perception and its dysfunction may lead on to schizophrenia. Digoxin can also preferentially upregulate tryptophan transport over tyrosine resulting in increased levels of depolarising tryptophan catabolites--serotonin and quinolinic acid (NMDA agonist), and decreased levels of hyperpolarising tyrosine catabolites--dopamine and noradrenaline contributing to membrane Na+-K+ ATPase inhibition. NMDA excitotoxicity could result from hypomagnesemia induced by membrane Na+-K+ ATPase inhibition and quinolinic acid, an NMDA agonist acting on the NMDA receptor. Hypomagnesemia and increased dolichol level can affect glycoconjugate metabolism and membranogenesis leading on to disordered synaptic connectivity in the limbic allocortex and defective presentation of viral antigens and neuronal antigens contributing to autoimmunity and viral persistance important in the pathogenesis. Membrane Na+-K+ ATPase inhibition can produce immune activation, a component of autoimmunity. Mitochondrial dysfunction consequent to altered calcium/magnesium ratios and reduced ubiquinone levels can result in increased free radical generation and reduced free radical scavenging & defective apoptosis leading on to abnormal synaptogenesis. Schizophrenia can thus be considered as a syndrome of hypothalamic digoxin hypersecretion consequent to an upregulated isoprenoid pathway.

Changes in the isoprenoid pathway in syndrome X

This study assessed the changes in digoxin and some other metabolites of the isoprenoid pathway in metabolic syndrome X presenting with multiple lacunar state. There was an increase in plasma HMG CoA reductase activity with a consequent increase in serum digoxin, which caused a reduction in RBC membrane Na+-K+ ATPase activity. There was an increase in serum tryptophan and its metabolites and a decrease in tyrosine and its metabolites. Serum magnesium was decreased with consequent alteration in the metabolism of glycosaminoglycans and glycolipids. Increase in dolichol, another product of the isoprenoid pathway resulted in alteration in glycoprotein metabolism. Changes in the composition of membrane glycosaminoglycans, glycoproteins and cholesterol:phospholipid ratio were also observed in this disorder leading to decreased lysosomal stability. Decrease in ubiquinone, another isoprenoid metabolite resulted in alteration in the free radical generation. Membrane Na+-K+ ATPase inhibition due to digoxin, altered membrane structure, increased tryptophan catabolites and decreased tyrosine catabolites can lead on to increased intracellular calcium and reduced intracellular magnesium which can account for the symptoms of syndrome X.

Hypothalamic digoxin and irritable bowel syndrome

BACKGROUND

The hypothalamus produces an endogenous membrane Na+-K+ ATPase inhibitor digoxin that can modulate neurotransmitter transport and may play a role in hemispheric dominance. It can also modulate glycoconjugate synthesis and thus affect synaptic connectivity in the bowel wall. Digoxin could play a role in the genesis of irritable bowel syndrome (IBS).

AIM

To study digoxin status in IBS and to correlate it with hemispheric dominance.

METHODS

The isoprenoid pathway, tryptophan/tyrosine catabolic patterns and glycoconjugate metabolism were assessed in patients with IBS and in right hemispheric dominant/left hemispheric dominant/bihemispheric dominant individuals.

RESULTS

The isoprenoid pathway was upregulated in IBS, with increased HMG CoA reductase activity (0.8 [0.07] vs 0.4 [0.06] in controls; p<0.01), serum digoxin (14.8 [1.0] vs 29.0 [1.2] ng/dL; p<0.01) and dolichol levels (63.8 [3.0] vs 120.3 [3.6] mg/dL; p<0.01). RBC membrane Na+-K+ ATPase activity (3.0 [0.2] vs 1.0 [0.1] microg/p/mg protein; p<0.01), serum magnesium (1.7 [0.1] vs 1.0 [0.1] mg/dL; p<0.01) and ubiquinone (86.4 [5.9] vs 39.8 [1.2] microg/dL; p<0.01) were reduced. There was increase in tryptophan catabolites and reduction in tyrosine catabolites. Serum total glycosaminoglycan and carbohydrate component of glycoproteins were increased in IBS. The activity of glycosaminoglycan degrading enzymes and glycohydrolases were increased. This pattern correlated with those obtained in right hemispheric chemical dominance.

CONCLUSION

Hypothalamic digoxin and right hemispheric dominance could play a role in the genesis of irritable bowel syndrome.

Membrane Na+ K+ ATPase inhibition related dyslipidemia and insulin resistance in neuropsychiatric disorders

There are several reports in literature implicating cholesterol metabolism in the pathogenesis of neuronal degenerations, oncogenesis, functional neuropsychiatric disorders and multiple sclerosis. Biosynthesis of cholesterol takes place by the isoprenoid pathway, which also produces digoxin, an inhibitor of membrane Na(+)-K+ ATPase. Inhibition of this enzyme results in intracellular Mg++ deficiency which can influence cholesterol metabolism. Digoxin also influences transport of tryptophan and tyrosine which are precursors of various neurotransmitters. Alterations in digoxin, membrane Na(+)-K+ ATPase and also in neurotransmitters have been reported in the disorders mentioned above. In view of this, serum lipid profile, activity of plasma HMG CoA reductase (the major rate limiting step in the isoprenoid pathway), RBC membrane Na(+)-K+ ATPase activity, serum Mg++ concentration, concentration of digoxin and concentration of serum neurotransmitters were studied in some neuropsychiatric disorders. The serum serotonin level was increased while that of serum dopamine and noradrenaline was reduced. Serum digoxin levels were high and RBC membrane sodium-potasium ATPase activity and serum magnesium were reduced. There was a reduction in HDL cholesterol and increase in plasma triglycerides (pattern similar to insulin resistance and syndrome X) in most of the disorders studied. The HMG CoA reductase activity was high, the serum total cholesterol was increased while RBC membrane cholesterol was reduced in most of the cases. The significance of increased digoxin with consequent inhibition of membrane Na(+)-K+ ATPase in relation to changes in cholesterol metabolism and insulin resistance type of dyslipidemia is discussed in this paper.

Ribonuclease Rs from Rhizopus stolonifer: lowering of optimum temperature in the presence of urea

RNase Rs showed an approx. 2-fold increase in its activity when incubated in the presence of 2 M urea at 37 degrees C. The increase in its activity, in the presence of urea, was comparable to the activity at its optimum temperature, i.e. 45 degrees C. Compared to the native enzyme at 37 degrees C, the K(m) and V(max) of RNase Rs at 45 degrees C and in the presence of 2 M urea at 37 degrees C showed an increase while k(cat)/K(m) decreased. Arrhenius plots in the presence and absence of urea showed a decrease in the activation energy in the presence of urea. Though there was no change in the secondary structure of the protein in the presence of urea, minor changes were observed in the tertiary structure. Hence, the increase in the activity of RNase Rs, in the presence of 2 M urea at 37 degrees C, is due to the lowering of the activation energy as a result of changes in the microenvironment of the active site.

Active site characterization of the single endo-polygalacturonase produced by Fusarium moniliforme NCIM 1276

Fusarium moniliforme NCIM 1276 isolated from a tropical mangrove ecosystem produces a single extracellular endo-polygalacturonase with an M(r) of 38 kDa and a carbohydrate content of 4%. It has an alkaline pI of 8.1. The K(m) is 0.12 mg.mL(-1), V(max) is 111.1 micromol.min(-1).mg(-1) and the kcat is 4200 min-1. It has a pH optimum of 4.8. Kinetic and fluorescence data show that tryptophan is involved in binding. An arginine residue at or near the active site may be involved in extended binding of the substrate. A carboxylate and a histidine residue are involved in catalysis. These data are discussed with reference to current literature.

Hypothalamic digoxin and neural regulation of blood pressure and vascular thrombosis

The isoprenoid pathway produces three key metabolites--digoxin (membrane sodium-potassium ATPase inhibitor and regulator of neurotransmitter/aminoacid transport), dolichol (regulates N-glycosylation of proteins) and ubiquinone (free radical scavenger). This was assessed in patients with essential hypertension, familial hypotension, acute coronary artery disease and acute thrombotic strokes. The pathway was also assessed in patients with right hemispheric, left hemispheric and bihemispheric dominance for comparison. In patients with acute coronary artery disease, acute thrombotic stroke, essential hypertension and right hemispheric dominance, there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels and low ubiquinone and high free radical levels. There was also an increase in tryptophan catabolites, reduction in tyrosine catabolites, increase in cholesterol-phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in this group of patients as well as in those with right hemispheric dominance. In patients with familial hypotension and left hemispheric dominance, the patterns were reversed. The role of a dysfunctional isoprenoid pathway and endogenous digoxin in the pathogenesis of essential hypertension and familial hypotension and in thrombotic vascular disease in relation to hemispheric dominance is discussed.

Transfer of interferon alfa into human breast milk

Originally assumed to be antiviral substances, the efficacy of interferons in a number of pathologies, including malignancies, multiple sclerosis, and other immune syndromes, is increasingly recognized. This study provides data on the transfer of interferon alfa (2B) into human milk of a patient receiving massive intravenous doses for the treatment of malignant melanoma. Following an intravenous dose of 30 million IU, the amount of interferon transferred into human milk was only slightly elevated (1551 IU/mL) when compared to control milk (1249 IU/mL). These data suggest that even following enormous doses, interferon is probably too large in molecular weight to transfer into human milk in clinically relevant amounts.

Surfactant protein-A: new insights into an old protein--II

Pulmonary surfactant is a lipoprotein substance that lines the lungs and helps reduce surface tension. Surfactant associated protein-A (SP-A) is the most abundant non-serum protein in pulmonary surfactant. This complex glycoprotein aids in the synthesis, secretion and recycling of surfactant phospholipids, and facilitates the reduction of surface tension by surfactant phospholipids. Recent evidence has highlighted the role of SP-A in the innate immune system present in the lung. SP-A may play a major role in defense against pathogens by interacting with both infectious agents and the immune system. Factors that affect fetal lung maturation, e.g. gestational age and hormones regulate SP-A gene expression. Mediators of immune function also regulate SP-A levels. A number of lung disorders, including infectious diseases and respiratory distress syndrome are associated with abnormal alveolar SP-A levels. SP-A can no longer be called a lung-specific protein, since it has recently been detected in other tissues. In most species, SP-A is encoded by a single gene, however in humans it is encoded by two, very similar genes. Models for the structure of the human SP-A protein molecule have been proposed, suggesting that the mature alveolar SP-A molecule is composed of both gene products. The study of SP-A may provide information helpful in understanding disease processes and formulating new treatment modalities.

Thermodynamics of ligand (substrate/end product) binding to endoxylanase from Chainia sp. (NCL-82-5-1): isothermal calorimetry and fluorescence titration studies

The binding of xylo-oligosaccharides to Chainia endoxylanase resulted in a decrease in fluorescence intensity of the enzyme with the formation of 1:1 complex. Equilibrium and thermodynamic parameters of ligand binding were determined by fluorescence titrations and titration calorimetry. The affinity of xylanase for the oligosaccharides increases in the order X2<X3<X4</=X5. Contributions from the enthalpy towards the free energy change decreased with increasing chain length from X2 to X4, whereas an increase in entropy was observed, the change in enthalpy and entropy of binding being compensatory. The entropically driven binding process suggested that hydrophobic interactions as well as hydrogen bonds play a predominant role in ligand binding.

SP-A2 gene expression in human fetal lung airways

In the present study, we characterized surfactant protein (SP)-A messenger RNA (mRNA) in mid-trimester human fetal trachea and bronchi. SP-A protein was localized by immunocytochemistry to scattered epithelial cells in the airway surface epithelium and in submucosal glands of the fetal trachea and bronchi. SP-A mRNA (2.2 kb) was detected by Northern blot analysis in human fetal trachea, as well as in primary and more distal bronchi. The levels of detectable SP-A mRNA were highest in the upper airways and were decreased in smaller bronchi in comparison. SP-A mRNA was barely detectable in the distal fetal lung tissue. In contrast, SP-A mRNA was abundant in cultured explants of distal human fetal lung tissue. SP-A1 and SP-A2 mRNA were detected by primer extension analysis in adult human lung tissue and in cultured human fetal lung explants. Only SP-A2 mRNA was detected in RNA isolated from human fetal trachea and bronchi. SP-A mRNA was localized by in situ hybridization in the fetal trachea and bronchi in scattered cells in the surface epithelium and, most prominently, in submucosal glands. Our results suggest that SP-A2, and not SP-A1, is produced in the human fetal tracheal and bronchial epithelium and in submucosal glands.

Surfactant protein-A: new insights into an old protein--Part I

Pulmonary surfactant is a lipoprotein substance that lines the lungs and helps reduce surface tension. Surfactant associated protein-A (SP-A) is the most abundant non-serum protein in pulmonary surfactant. This complex glycoprotein aids in the synthesis, secretion and recycling of surfactant phospholipids, and facilitates the reduction of surface tension by surfactant phospholipids. Recent evidence has highlighted the role of SP-A in the innate immune system present in the lung. SP-A may play a major role in defense against pathogens by interacting with both infectious agents and the immune system. Factors that affect fetal lung maturation, e.g., gestational age and hormones, regulate SP-A gene expression. Mediators of immune function also regulate SP-A levels. A number of lung disorders, including infectious diseases and respiratory distress syndrome are associated with abnormal alveolar SP-A levels. SP-A can no longer be called a lung-specific protein, since it has recently been detected in other tissues. In most species, SP-A is encoded by a single gene, however in humans it is encoded by two, very similar genes. Models for the structure of the human SP-A protein molecule have been proposed, suggesting that the mature alveolar SP-A molecule is composed of both gene products. The study of SP-A may provide information helpful in understanding disease processes and formulating new treatment modalities.

O2 regulates surfactant protein A mRNA transcription and stability in human fetal lung in vitro

The effect of O2 on surfactant protein (SP) A mRNA transcription and half-life was determined in midtrimester human fetal lung tissue cultured in either 20 (control) or 70% O2. Incubation of tissues in 70% O2 resulted in a 133% increase in SP-A mRNA transcription rate compared with control tissues. The SP-A mRNA half-life was increased by 54% in lung tissues cultured in 70% O2 vs. control tissues. Western blot analysis indicated a threefold increase in SP-A in the 70% O2 condition, demonstrating that O2 regulation of SP-A mRNA levels results in corresponding changes in SP-A levels. Primer extension assays were performed to determine whether the observed increase in SP-A mRNA levels is secondary to the preferential expression of one of the human SP-A genes, SP-A1 or SP-A2. Transcripts of both the SP-A1 and SP-A2 genes were increased approximately 100% in tissues maintained in 70% O2 compared with control tissues. These data demonstrate that O2 regulates human SP-A mRNA levels by both transcriptional and posttranscriptional mechanisms. Furthermore, because there is no differential effect of O2 on the expression of SP-A1 vs. SP-A2 mRNA, the properties of these genes that mediate regulation by O2 must be conserved between the two genes.

Differential regulation of SP-A1 and SP-A2 genes by cAMP, glucocorticoids, and insulin

In the human fetal lung, surfactant protein A (SP-A) is encoded by two highly similar genes, SP-A1 and SP-A2, which are developmentally and hormonally regulated. Using primer extension analysis, we evaluated the levels of SP-A1 and SP-A2 mRNA transcripts in human fetal lung explants and in a human adult lung adenocarcinoma cell line (H441 cells) cultured in the absence or presence of either dibutyryladenosine 3',5'-cyclic monophosphate (DBcAMP, 1 mM), dexamethasone (10(-7) M), or insulin (2.5 micrograms/ml). In the human fetal lung explants, the content of SP-A1 mRNA was approximately four times that of SP-A2 mRNA. DBcAMP increased SP-A1 mRNA levels by 100% and SP-A2 mRNA levels by 500%, thus reducing the ratio of SP-A1 mRNA to SP-A2 mRNA to approximately 1:1. Dexamethasone inhibited all of the SP-A1 and SP-A2 mRNA transcripts to the same extent, by approximately 70%, whereas insulin inhibited all SP-A mRNA transcripts by approximately 60%. The ratio of SP-A1 to SP-A2 mRNA in dexamethasone- or insulin-treated explants was the same as the ratio observed in controls. In the H441 cells, SP-A1 mRNA levels were approximately 1.5 times that of SP-A2 mRNA levels. DBcAMP increased both SP-A1 and SP-A2 mRNA levels by 100%. Dexamethasone inhibited SP-A1 mRNA levels in the cell line by 60%, whereas SP-A2 mRNA levels were not significantly affected. Insulin inhibited SP-A1 mRNA levels in the cell line by 40% without affecting SP-A2 mRNA levels. These findings suggest that the two human SP-A genes are regulated differently in the two model systems.

Histiocytosis-X of fronto-ethmoid region

Histiocytosis-X is a rare disease. It occurs mostly in children. Aetiology is unknown. Treatment is by surgery, Radiotherapy and Chemotherapy, either singly or in combination. Prognosis depends on the degree of involvement. One such case is reported and discussed.

Anthropometric and clinical nutrition status of workers in some Indian factories

Anthropometric and clinical nutritional status of 195 male factory workers was assessed in Nainital, North India. Relationships between anthropometry and clinical scores and between nutritional status and either education or income were evaluated. Mean ± standard deviation values were: height 161.3 ± 6.0 cm, weight 52.7± 7.6 kg, BMI 20.2 ± 2.4 and MUAC 24.0 ± 2.3 cm. For BMI, 57% of the subjects were below 20, a value below which FAO predicts that there will be increased risk of work performance. Values corresponding to chronic energy undernutrition (below 18.5 BMI) were found in about 20% of workers. Clinical signs of nutritional deficiencies were found to be 10.76% for vitamin B complex, 2.05% for ascorbic acid and 2.05% for iron. Clinical scores and anthropometric values were negatively correlated with each other, indicating that clinical signs of nutritional deficiencies increased with decreasing anthropometric values. Education and per capita income appeared to have a positive influence on nutritional status.

Analyzing and modeling fractal intensity point processes

Fractal intensity point processes--doubly stochastic point processes with a fractal waveform intensity process--are required to describe the discharge patterns recorded from the auditory and visual systems. The Fano factor--the ratio of the variance of the number of events in an interval to the mean of this number--captures the self-similar characteristics of the intensity via two quantities: fractal dimension and fractal time. The fractal dimension is the exponent of the asymptotic power law behavior of the Fano factor with interval duration. The fractal time delineates long-term fractal behavior from short-term characteristics of the data. The average rate and self-similarity parameter of the intensity process, absolute and relative refractory effects, and serial dependence all modify the fractal time. To generate fractal intensity point processes, stochastic fractal processes are derived by applying memoryless, nonlinear transformations to fractional Gaussian noise. The intensity's amplitude distribution in combination with the Fano factor form criteria to choose the transformation that best describes data.

Infant growth in relation to feeding practices in low income families

A survey of feeding practices and measurements of weight, length and chest circumference of infants upto the age of 12 months and belonging to low income families of some selected villages at Pantnagar was carried out during 1987-88. The study revealed that as many as 83% of infants were exclusively breast fed up to the age of 6 months. In addition to being breast fed, 77% of infants between 9 and 12 months were also receiving semi-solids. Very small quantities of cereals, pulses, biscuits and fruits were reported to be the supplementary foods fed to infants. Animal milk diluted to varying degrees was fed as a supplement by some mothers and as a substitute by a few. Growth patterns of various feed types in terms of the anthropometric measurements were not found significantly different in different feeding practices. With reference to International standards (NCHS), it was seen that weight of only 25% of male and 55% of female infants fell in the normal range at the age of 3 months and this percentage declined from 3rd month to 12th month of age. Though the percentage falling in normal range was higher for length, the pattern of decline with the advancement in age was similar. This unsatisfactory growth performance of even those who received other foods along with breast milk is indicative of the fact that the quantity/quality of supplementary foods (along with other factors) were not sufficient to promote normal growth.

Rate fluctuations and fractional power-law noise recorded from cells in the lower auditory pathway of the cat

The noise properties of the sequence of action potentials recorded from adult-cat auditory nerve fibers and lateral superior olivary units have been investigated under various stimulus conditions. Large fluctuations exhibited by the spike rate, and spike clusters evident in the pulse-number distribution, both indicate an unusual underlying sequence of neural events. We present results demonstrating that (i) the firing rate calculated with different averaging times can exhibit self-similar behavior; (ii) the pulse-number distribution remains irregular even for large numbers of samples; (iii) the spike-number variance-to-mean ratio increases with the counting time T in fractional power-law fashion for sufficiently large T; and (iv) the exponent in the power law generally depends on the stimulus level. The results obtained in our laboratories support the notion that all auditory-nerve and LSO units exhibit fractal neural firing patterns, as indicated earlier by Teich (IEEE Trans. Biomed. Eng. 36, 150-160, 1989).

Phase II study of procarbazine, CCNU, and vincristine combination chemotherapy in the treatment of malignant brain tumors

Forty-eight patients with primary or metastatic malignant tumors of the central nervous system (CNS) were treated with combination chemotherapy, consisting or procarbazine (100 mg/m2 X 14 days), CCNU (75 mg/m2), and vincristine (1.4 mg/m2 X 2, 1 week apart) (PCV) every 4 weeks. Most patients had undergone initial resection of primary tumors, postoperative radiotherapy, and a post irradiation interval of 3 months or more. Other patients harbored unbiopsied, newly-discovered primary or metastatic tumors. All patients were deteriorating neurologically when treatment began. Overall response rate for PCV combination therapy was 44%, no better than results obtained with single agent procarbazine or BCNU, the most effective drugs used alone in previous brain tumor chemotherapy studies.