Deficient Types Research Articles

Portreti manjkavog učeništva

This paper aims to explore the way the evangelist Matthew illustrates the deficiency of discipleship by sketching three portrayals of deficient discipleship. The section under scrutiny is that of chapter 8:18-27 from Matthew’s Gospel. The first portrayal is that of a disciple-to-be, described in terms of much enthusiasm without much understanding of the kind of teacher Jesus is (Matt 8:19-20). He is a proper illustration of the first type of deficient human attempt to follow Jesus, namely, discipleship without costs. The second portrayal, is that of an acknowledged disciple, described in terms of manifest hesitation that comes from an insufficient clarification of his existential priorities and of the kind of master Jesus is (Matt 8:21-22). This portrayal is a helpful illustration of the second type of deficient attempt to follow Jesus, namely, discipleship without commitment. The third portrayal is that of the called disciples, described in terms of fear that comes from the lack of understanding of the kind of Lord Jesus is (Matt 8:23-27). This portrayal is a realistic illustration of the third type of deficient human attempt to follow Jesus, namely, discipleship without hardships. Yet, in his answers in the encounters with the three categories of protagonists in the biblical text, Jesus offers corrections to all three types of deficient discipleship. And Matthew combines the revelation of the symptoms of the three deficient types of discipleship with the solution coming from Jesus’ answers, to make the recipient-audience of his Gospel understand that discipleship is costly, is based on commitment, and involves hardships.

Do infrastructure deserts exist? Measuring and mapping infrastructure equity: A case study in Dallas, Texas, USA

Neighborhood infrastructure, such as sidewalks, medical facilities, public transit, community gathering places, and tree canopy, provides essential support for safe, healthy, and resilient communities. This paper examines the presence and condition of neighborhood infrastructure and shows that “infrastructure deserts” exist, which are low-income neighborhoods with significantly more deficient infrastructure. A generalized data-driven framework is developed and implemented at the street-level for 12 types of neighborhood infrastructure in Dallas, Texas. The results show significant infrastructure inequities across income levels for most types of infrastructure. Statistical inference predicts (with 95 % confidence) that low-income neighborhoods are 2.0 to 3.5 times more likely to have highly deficient infrastructure (8 or more deficient infrastructure types) than high-income areas and 1.4 to 2.4 times more likely to have highly deficient infrastructure than middle-income neighborhoods. This paper addresses the methodological challenge of considering multiple infrastructure types and provides a guide for infrastructure investment prioritization.

BH4-deficient hyperphenylalaninemia in Russia.

A timely detection of patients with tetrahydrobiopterin (BH4) -deficient types of hyperphenylalaninemia (HPABH4) is important for assignment of correct therapy, allowing to avoid complications. Often HPABH4 patients receive the same therapy as phenylalanine hydroxylase (PAH) -deficiency (phenylketonuria) patients—dietary treatment—and do not receive substitutive BH4 therapy until the diagnosis is confirmed by molecular genetic means. In this study, we present a cohort of 30 Russian patients with HPABH4 with detected variants in genes causing different types of HPA. Family diagnostics and biochemical urinary pterin spectrum analyses were carried out. HPABH4A is shown to be the prevalent type, 83.3% of all HPABH4 cases. The mutation spectrum for the PTS gene was defined, the most common variants in Russia were p.Thr106Met—32%, p.Asn72Lys—20%, p.Arg9His—8%, p.Ser32Gly—6%. We also detected 7 novel PTS variants and 3 novel QDPR variants. HPABH4 prevalence was estimated to be 0.5–0.9% of all HPA cases in Russia, which is significantly lower than in European countries on average, China, and Saudi Arabia. The results of this research show the necessity of introducing differential diagnostics for HPABH4 into neonatal screening practice.

Clinical and psychological approaches to the diagnosis of children with autism spectrum disorders

IntroductionThe importance of clinical diagnosis of autism spectrum disorders (ASD) in childhood is due to the timely detection of ASD and the appropriate early start of patient care, depending on the form of ASD. The experience of multidisciplinary collaboration between medical psychologists and clinicians in child psychiatric practice allows us to more accurately determine the depth and severity of autistic manifestations, determine the dynamics of child development, and provide personalized effective care.ObjectivesDevelop diagnostic, clinical and psychological approaches to the diagnosis of ASD.MethodsClinical-psychopathological, clinical-dynamic, clinical-catamnestic, and psychological methods were used. 254 patients aged 4-17 years (average – 7.3 years) with different forms of ASD were examined.Results From the clinical and pathopsychological positions, profiles of six main forms of ASD are identified. Each of the selected profiles corresponds to a specific type of cognitive dysontogenezis. A distorted view of cognitive dysontogenezis in Asperger’s syndrome (F84. 5) and childhood autism dysontogenetic (F84.0). Distorted or deficient types of cognitive dysontogenezis in children’s psychosis (F84. 02). Deficient type of cognitive dysontogenezis in Kanner syndrome (F84. 01). Defecating type of cognitive dysontogenezis in atypical autism syndromal (F84. 11), deficient and regressive-defecating types of cognitive dysontogenezis in atypical child psychosis (F84.12).ConclusionsA three-dimensional model is obtained that allows the most accurate diagnosis of various forms of ASD and the development of personalized routes for patient care and rehabilitation, taking into account the type of cognitive dysontogenezis and based on the zone of the child’s immediate development.

Aqueous deficiency is a contributor to evaporation-related dry eye disease

Dry eye disease aetiologies can be classified dichotomously into aqueous deficient and evaporative types although many cases involve combinations of both. Differential diagnosis can be confounded by some features of dry eye disease being common to both aetiologies. For example, short tear break-up times are prime diagnostic findings of tear instability due to lipid and/or mucin deficiencies, but thin tear layers in aqueous deficient eyes also shorten tear break-up times, even at normal range rates of evaporation in eyes without lipid and/or mucin deficiencies. Because tear instability and short tear film break-up times due to thin tear layers can be independent of lipid and/or mucin deficiency, aqueous deficiency can be another form of evaporation-related dry eye. Conversely, tear layers which are thickened by punctal occlusion can be less susceptible to tear break-up. An inflamed lacrimal gland producing reduced quantities of warmer tears can be a basis for thin tear layers and tear instability demonstrated by shorter tear break-up times. Commonly used clinical tests for aqueous deficiency can be unreliable and less sensitive. Consequently, failure to detect or confirm aqueous deficiency as a contributor to short tear break-up times could result in too much weight being given to a diagnosis of meibomian gland deficiency. Less successful treatment outcomes may be a consequence of failing to detect aqueous deficiency. Refining disease classification by considering aqueous deficiency as a contributor to, or even a form of evaporation-related dry eye, could be the basis for more comprehensive and appropriate treatment strategies. For example, some treatment methods for evaporation-related dry eye might be appropriate for aqueous and mucin-deficient as well as lipid-deficient dry eyes. Anti-inflammatory treatment for the lacrimal gland as well as the conjunctiva, may result in increased aqueous production, reduced tear temperature, tear instability and evaporation rates as well as lower osmolarity.

Analysis of DNA mismatch repair (MMR) and clinical outcome in stage III colon cancers from patients (pts) treated with adjuvant FOLFOX +/- cetuximab in the PETACC8 and NCCTG N0147 adjuvant trials.

3506 Background: The prognostic impact of deficient (d) MMR, including sporadic and familial types, in stage III colon cancer pts receiving standard adjuvant FOLFOX therapy remains unknown. We exam...

Abstract 1713: PDK1 and hexokinase 2 are downstream effectors of PTEN loss and regulate response to targeted therapies in multiple tumor types

Abstract Recent advances in molecular profiling of many human tumor types has enabled the development and clinical use of molecularly-targeted therapies in patients. Many tumors exhibit inactivation of PTEN which is predicted to sensitize tumor cells to PI3 kinase or AKT inhibitor therapy. However, clinical responses to PI3 kinase or AKT inhibitors are variable and not curative. Furthermore, these responses in patients do not correlate uniformly with PTEN inactivation. Therefore, we investigated whether PTEN inactivation could lead to dependence on signaling pathways and components that function independently of PI3K or AKT and that could serve as novel therapeutic targets in PTEN deficient tumors. Using multiple human tumor models including lung adenocarcinoma, lung squamous, renal cell carcinoma, and prostate adenocarcinoma that express or lack PTEN and Gene Set Enrichment Analysis, we identified alterations in numerous metabolic regulatory genes in response to PTEN inactivation, including hexokinase 2 (HK2) and pyruvate dehydrogenase kinase 1 (PDK1). We found that in PTEN-deficient tumor cells HK2 is upregulated and selectively localizes to the mitochondria, where it enhances glycolytic flux and inhibits apoptosis. Furthermore, we found that PDK1 is also upregulated upon PTEN inactivation and suppresses oxidative phosphorylation, upregulating glycolysis and the production of lactate. Thus, we uncovered a novel role for HK2 and PDK1 in the metabolic reprogramming that occurs as a consequence of PTEN inactivation in tumor cells. Furthermore, we found that overexpression of either HK2 or PDK1 confers resistance to targeted therapies against PI3K and other oncogenic drivers more broadly. Conversely, genetic or pharmacological suppression of HK2 or PDK1 enhances response to targeted therapy in multiple tumor cell types. Together, our data identify HK2 and PDK1 as novel molecular biomarkers and promising therapeutic targets in multiple PTEN deficient tumor types. Citation Format: Evangelos Pazarentzos, Trever G. Bivona. PDK1 and hexokinase 2 are downstream effectors of PTEN loss and regulate response to targeted therapies in multiple tumor types. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1713. doi:10.1158/1538-7445.AM2014-1713

Perturbed Hematopoiesis In Mice Lacking ATMIN (an ATM co-Factor)

ATM (Ataxia telangiectasia mutated) kinase plays important roles in hematopoiesis. Two co-factors participate in ATM activation in a signal-dependent manner: NBS1 during ionising radiation induced DNA damage and ATMIN under hypotonic stress or chloroquine treatment, presumably due to changes in chromatin structure. Such artificial treatments might not have a genuine biological significance. However, we have recently shown a potential role for ATMIN in B cells. CD19-Cre mediated deletion of Atmin led to impaired class switch recombination, greatly increased genomic instability and consequently the development of B cell lymphomas. Considerable (but not total) overlap in phenotypes was found in ATM and ATMIN deficient B cells suggesting that ablation of ATMIN alters ATM function. As Atm-/- HSCs have impaired quiescence, maintenance and reconstitution capacity due to elevated reactive oxygen species, we sought to investigate if the absence of ATMIN would affect the primitive hematopoietic compartment. We used a Vav-Cre approach to delete Atmin to test ATMIN's functions in the hematopoietic system (simply referred as AtminΔ/Δ).At steady state, AtminΔ/Δ mice have ∼75% reduction in total splenocytes as compared to control mice. This is mainly due to reduced B cell, but also T cell, numbers. However, AtminΔ/Δ mice do not develop B cell lymphomas but they present differentiation block at the pre-B cell and at the immature/mature re-circulating B (IgM+/hi) cell stages with more than a 2-fold increase in apoptosis in these cell fractions compared to controls. The lack of lymphoma development in these mice suggests that the lack of ATMIN would also affect the more primitive compartment (e.g. CLP), not allowing tumorigenic clones to accumulate. Indeed, in the bone marrow (BM), a ∼40% reduction in total cellularity was observed in ATMIN deficient mice compared to littermate controls at 8-12 wks of age. This reduction in total cellularity is reflected across the board, from LT-HSCs (LSK/CD34-/lo/Flt3-) to the more mature cells and, more evidently, B cells. Apart from a similar B cell maturation block seen in the spleen, the frequency of CMPs (LS-K/IL7R-/CD34+/FcγR−) and GMPs (LS-K/IL7R-/CD34+/FcγR+) were reduced by 3- and 2-fold, respectively, in ATMIN deficient mice. The frequencies of other primitive compartments were not different in ATMIN deficient mice vs controls, including the CLP (LS-Klo/IL7R+) fraction. This reduction in CMP and GMP fractions translated into a ∼50% reduction in CFU capacity. Interestingly, only LT-HSCs, ST-HSCs and MPPs were found to be more cycling in the absence of ATMIN, suggesting a compensatory mechanism due to the reduction in some of the compartments downstream of LSK. Unlike in B cells, no increase in apoptosis was found in any other ATMIN deficient BM cell types, implying that the function of ATMIN is dependent on the context of the cell.When transplanting similar numbers of ATMIN or control LT-HSCs, the regenerative capacity of AtminΔ/Δ-Vav-Cre cells was reduced by ∼16-fold in peripheral blood at 16 wks post-transplantation, with an early pronounced ∼10-fold reduction in B220+ cell production that was maintained over time. We found a steady decline in the production of myeloid cells over time, reaching a ∼13-fold difference between AtminΔ/Δ-Vav-Cre and control transplanted cells. However, in secondary recipients transplanted with a similar number of LSK cells, the regenerative capacity of AtminΔ/Δ-Vav-Cre cells was only further reduced to ∼24-fold as compared to control cells at 16 wks post-transplant. Interestingly, when transplanting ST-HSCs, the regenerative capacity of this fraction was even more drastically reduced, reaching ∼51-fold difference between AtminΔ/Δ-Vav-Cre and control cells.Contrary to our predictions, oxidative stress does not seem to play any evident role in reducing CMP and GMP fractions. Interestingly, however, we observed a mild but significant phosphorylation of H2AX and a specific ATM substrate, KAP1, in only these myeloid progenitors suggesting activation of ATM signaling. Further studies are on going to test whether this to due to replicative stress.Overall, our studies highlight that ATMIN appears to have different roles in different cells and potential novel ATM-independent functions. Certainly, in the absence of ATMIN, hematopoiesis is severely altered, directly and/or indirectly affecting the function of LT-HSCs. Disclosures:No relevant conflicts of interest to declare.

Regulation of mTOR Complex 2 Signaling in Neurofibromatosis 2–Deficient Target Cell Types

Inactivating mutations in the neurofibromatosis 2 (NF2) tumor suppressor gene results in the development of schwannomas and meningiomas. Using NF2-deficient meningioma cells and tumors, together with the normal cellular counterparts that meningiomas derive, arachnoid cells, we identified merlin as a novel negative regulator of mTOR complex 1 (mTORC1). We now show that merlin positively regulates the kinase activity of mTORC2, a second functionally distinct mTOR complex, and that downstream phosphorylation of mTORC2 substrates, including Akt, is reduced upon acute merlin deficiency in cells. In response to general growth factor stimulation, Akt signaling is attenuated in merlin RNA interference-suppressed human arachnoid and Schwann cells by mechanisms mediated by hyperactive mTORC1 and impaired mTORC2. Moreover, Akt signaling is impaired differentially in a cell type-dependent manner in response to distinct growth factor stimuli. However, contrary to activation of mTORC1, the attenuated mTORC2 signaling profiles exhibited by normal arachnoid and Schwann cells in response to acute merlin loss were not consistently reflected in NF2-deficient meningiomas and schwannomas, suggesting additional genetic events may have been acquired in tumors after initial merlin loss. This finding contrasts with another benign tumor disorder, tuberous sclerosis complex, which exhibits attenuated mTORC2 signaling profiles in both cells and tumors. Finally, we examined rapamycin, as well as the mTOR kinase inhibitor, Torin1, targeting both mTOR complexes to identify the most efficacious class of compounds for blocking mTOR-mediated signaling and proliferation in merlin-deficient meningioma cells. These studies may ultimately aid in the development of suitable therapeutics for NF2-associated tumors.

Alterations of OprD in Carbapenem-Intermediate and -Susceptible Strains of Pseudomonas aeruginosa Isolated from Patients with Bacteremia in a Spanish Multicenter Study

We investigated the presence of OprD mutations in 60 strains of metallo-ß-lactamase-negative Pseudomonas aeruginosa intermediately susceptible (IS [n = 12]; MIC = 8 μg/ml) or susceptible (S [n = 48]; MICs ≤ 1 to 4 μg/ml) to imipenem and/or meropenem that were isolated from patients with bacteremia in order to evaluate their impact on carbapenem susceptibility profiles. The presence of mutations in oprD was detected by sequencing analysis. OprD expression was assessed by both outer membrane protein (OMP) analysis and real-time PCR (RT-PCR). Fourteen (23%) isolates had an OprD identical to that of PAO1, and OprD modifications were detected in 46 isolates (77%). Isolates were classified as OprD "full-length types" (T1 [n = 40, including both wild-type OprD and variants showing several polymorphisms]) and OprD "deficient types" (T2 [n = 3 for OprD frameshift mutations] and T3 [n = 17 for premature stop codons in oprD]). RT-PCR showed that 5 OprD type T1 isolates presented reduced transcription of oprD (0.1- to 0.4-fold compared to PAO1), while oprD levels increased more than 2-fold over that seen with PAO1 in 4 OprD type T1 isolates. A total of 50% of the isolates belonging to OprD "deficient types" were susceptible to both carbapenems, and 40% were susceptible to meropenem and intermediately susceptible to imipenem. Only one isolate (5%) within this group was intermediately susceptible to both carbapenems, and one (5%) was susceptible to imipenem and intermediately susceptible to meropenem. We concluded that OprD inactivating mutations in clinical isolates of P. aeruginosa are not restricted only to carbapenem-resistant isolates but are also found in isolates with imipenem or meropenem MICs of only 0.06 to 4 μg/ml.

Ataxia telangiectasia-mutated protein and DNA-dependent protein kinase have complementary V(D)J recombination functions

Antigen receptor variable region exons are assembled during lymphocyte development from variable (V), diversity (D), and joining (J) gene segments. Each germ-line gene segment is flanked by recombination signal sequences (RSs). Recombination-activating gene endonuclease initiates V(D)J recombination by cleaving a pair of gene segments at their junction with flanking RSs to generate covalently sealed (hairpinned) coding ends (CEs) and blunt 5'-phosphorylated RS ends (SEs). Subsequently, nonhomologous end joining (NHEJ) opens, processes, and fuses CEs to form coding joins (CJs) and precisely joins SEs to form signal joins (SJs). DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activates Artemis endonuclease to open and process hairpinned CEs before their fusion into CJs by other NHEJ factors. Although DNA-PKcs is absolutely required for CJs, SJs are formed to variable degrees and with variable fidelity in different DNA-PKcs-deficient cell types. Thus, other factors may compensate for DNA-PKcs function in SJ formation. DNA-PKcs and the ataxia telangiectasia-mutated (ATM) kinase are members of the same family, and they share common substrates in the DNA damage response. Although ATM deficiency compromises chromosomal V(D)J CJ formation, it has no reported role in SJ formation in normal cells. Here, we report that DNA-PKcs and ATM have redundant functions in SJ formation. Thus, combined DNA-PKcs and ATM deficiency during V(D)J recombination leads to accumulation of unjoined SEs and lack of SJ fidelity. Moreover, treatment of DNA-PKcs- or ATM-deficient cells, respectively, with specific kinase inhibitors for ATM or DNA-PKcs recapitulates SJ defects, indicating that the overlapping V(D)J recombination functions of ATM and DNA-PKcs are mediated through their kinase activities.

Role of expression of FIP200 protein in progression of hepatocellular carcinoma

e22147 Background: FIP200 protein is a newly identified protein, and recent report has shown that FIP200 interacts with p53 and inhibit progression and proliferation. Although expression of FIP200 has been confirmed in normal liver,the expression and function in human HCC is completely unknown. In this study, we examined expression of FIP200 in HCC cell lines and investigated the involvement of FIP200 in proliferation and apoptosis. We also examined expression of FIP200 using HCC tissues and the correlation between FIP200 expression and clinical outcome. Methods: The study was conducted using HCC cell lines (HepG2, HuH7, and Hep3B). P53 status in HepG2, HuH7 and Hep3B are wild type, mutant type and deficient types respectively. Expression of endogenous FIP200 was assessed by western blotting. To investigate antitumor function, we carried out BrdU incorporation assay with transfected FIP200. TUNEL was carried out for identification of apoptosis. We also reviewed 14 patients who had undergone initial liver resection for HCC. Immunohistochemistry analysis for FIP200 was performed and we investigated the FIP200 expression levels according to differentiation degree of HCC tissues. Results: Endogenous FIP200 was detected in all cell lines, and those expression levels were different among cell lines. Overexpression of FIP200 significantly decreased BrdU incorporation in HepG2 and HuH7 but not Hep3B. In the study of TUNEL, apoptosis was observed for p53 wild HepG2 transfected with FIP200. In Hep3B, there was no significant difference observed. As for clinical samples, FIP200 were detected in all HCC and non-HCC tissues. FIP200 expression levels in HCC tissues were decreased compared to non-HCC tissues. Furthermore, as differentiation degree poored, those expression levels were decreased in the same tissue as well as in the different tissue. Conclusions: Endogenous FIP200 was expressed in all cell line. Those expression levels were different according to p53 status. Our study demonstrated that FIP200 inhibit proliferation in HCC expressed p53, and induce apoptosis in p53 wild HCC but not p53 deficient HCC. Furthermore, the FIP200 expression levels were significantly associated with differentiation degree. These data suggest that FIP200 plays an important role in promoting tumor progression in HCC. No significant financial relationships to disclose.

Clinical Summaries

Clinical Summaries

Deficiency in the Catalytic Subunit of DNA-Dependent Protein Kinase Causes Down-Regulation of ATM

Previous reports have suggested a connection between reduced levels of the catalytic subunit of DNA-dependent protein kinases (DNA-PKcs), a component of the nonhomologous DNA double-strand breaks end-joining system, and a reduction in ATM. We studied this possible connection in other DNA-PKcs-deficient cell types, and following knockdown of DNA-PKcs with small interfering RNA, Chinese hamster ovary V3 cells, lacking DNA-PKcs, had reduced levels of ATM and hSMG-1, but both were restored after transfection with PRKDC. Atm levels were also reduced in murine scid cells. Reduction of ATM in a human glioma cell line lacking DNA-PKcs was accompanied by defective signaling through downstream substrates, post-irradiation. A large reduction of DNA-PKcs was achieved in normal human fibroblasts after transfection with two DNA-PKcs small interfering RNA sequences. This was accompanied by a reduction in ATM. These data were confirmed using immunocytochemical detection of the proteins. Within hours after transfection, a decline in PRKDC mRNA was seen, followed by a more gradual decline in DNA-PKcs protein beginning 1 day after transfection. No change in ATM mRNA was observed for 2 days post-transfection. Only after the DNA-PKcs reduction occurred was a reduction in ATM mRNA observed, beginning 2 days post-transfection. The amount of ATM began to decline, starting about 3 days post-treatment, then it declined to levels comparable to DNA-PKcs. Both proteins returned to normal levels at later times. These data illustrate a potentially important cross-regulation between the nonhomologous end-joining system for rejoining of DNA double-strand breaks and the ATM-dependent damage response network of pathways, both of which operate to maintain the integrity of the genome.

Efficient retrovirus-mediated PIG-A gene transfer and stable restoration of GPI-anchored protein expression in cells with the PNH phenotype

AbstractParoxysmal nocturnal hemoglobinuria (PNH) is a clonal hematopoietic stem cell disorder characterized by complement-mediated hemolysis due to deficiencies of glycosylphosphatidylinositol-anchored proteins (GPI-APs) in subpopulations of blood cells. Acquired mutations in the X-linked phosphatidylinositol glycan–class A (PIG-A) gene appear to be the characteristic and pathogenetic cause of PNH. To develop a gene therapy approach for PNH, a retroviral vector construct, termed MPIN, was made containing the PIG-A complementary DNA along with an internal ribosome entry site and the nerve growth factor receptor (NGFR) as a selectable marker. MPIN transduction led to efficient and stable PIG-A and NGFR gene expression in a PIG-A–deficient B-cell line (JY5), a PIG-A–deficient K562 cell line, an Epstein-Barr virus–transformed B-cell line (TK-14−) established from a patient with PNH, as well as peripheral blood (PB) mononuclear cells from a patient with PNH. PIG-A expression in these cell lines stably restored GPI-AP expression. MPIN was transduced into bone marrow mononuclear cells from a patient with PNH, and myeloid/erythroid colonies and erythroid cells were derived. These transduced erythroid cells restored surface expression of GPI-APs and resistance to hemolysis. These results indicate that MPIN is capable of efficient and stable functional restoration of GPI-APs in a variety of PIG-A–deficient hematopoietic cell types. Furthermore, MPIN also transduced into PB CD34+ cells from a normal donor, indicating that MPIN can transduce primitive human progenitors. These findings set the stage for determining whether MPIN can restore PIG-A function in multipotential stem cells, thereby providing a potential new therapeutic option in PNH.

Alcoholism and Carcinoma Change the Intracellular PH and Activate Platelet Na+/H+‐Exchange in Men

The occurrence of carcinoma in chronic alcoholics exceeds that of the general population. Cytoplasmic alkalinization, due to the influence of different factors on the transmembrane Na+/H+ exchange (NHE), has been put forward as a triggering event in cell growth and division. In accordance with these findings, the carcinogenic potential of NHE deficient cell types is reported to be diminished. The aim of this study was to investigate whether the intracellular pH and the NHE activity is altered in chronic alcoholics. Seventy-two Caucasian males were assigned to one of four groups: non-alcoholics without carcinoma, chronic alcoholics without carcinoma, non-alcoholics with carcinoma and chronic alcoholics with carcinoma. Alcoholism was diagnosed according to DSM-III-R. The groups did not differ in relation to basic patient characteristics, such as age and blood pressure. Intracellular calcium, pH and NHE in platelets were determined by spectrofluorometry before and after thrombin stimulation. In chronic alcoholics with carcinoma, the intracellular pH was significantly more alkaline and the NHE activity was elevated. In contrast, a decrease in intracellular pH associated with an increased activity of NHE and a more acidic set point was found in chronic alcoholics without carcinoma. Basal and thrombin stimulated intracellular Ca2+ did not differ between groups except in chronic alcoholics with carcinoma in whom a thrombin-induced increase of Ca2+ due to liberation of Ca2+ from intracellular stores was demonstrated. In chronic alcoholics with carcinoma, cytoplasmic alkalinization was observed and this may be an indication of an increase in cell proliferation. The possibility that the increased incidence of carcinomas in chronic alcoholics is related to the increased activity of NHE and whether this may be prevented by NHE inhibitors requires further investigation.

Characterization of the three genotypes of low Km aldehyde dehydrogenase in a Japanese population

A deficiency in low Km aldehyde dehydrogenase (ALDH2) is regarded as the main factor responsible for "Oriental flushing" and other symptoms due to alcohol sensitivity. In this study, the relationship of the ALDH2 genotype to alcohol-associated symptoms and drinking behavior was investigated in 524 Japanese workers, using a new, rapid, and nonisotopic polymerase chain reaction (PCR) method. Differences in the frequency of alcohol-associated manifestations between the normal homozygote and the other deficient types were apparent. In addition, among the ALDH2-deficient individuals, the atypical homozygote was obviously more hypersensitive to alcohol than the heterozygote, judging from the frequency of flushing or other drinking-associated manifestations with a small dose of alcohol. Drinking frequency also apparently decreased in the following order: typical homozygote, heterozygote, atypical homozygote. Similarly, mean amounts of alcohol consumption also decreased in the same order, although considerable variation existed within the typical homozygote and the heterozygote group. In contrast, neither the manifestations nor the drinking behavior were, in general, influenced by polymorphism of the alcohol dehydrogenase beta-subunit (ADH2) gene in males. These findings further indicate the important contribution of the ALDH2 genotype to alcohol sensitivity in Orientals.

The adaptation of Plasmodium falciparum to oxidative stress in G6PD deficient human erythrocytes.

It has recently been found that growth of P. falciparum in human G6PD deficient red cells is impaired in vitro; however, the inhibition is overcome after two or three growth cycles. There is evidence to suggest that the parasite can produce its own G6PD enzyme which may compensate for the lack of host enzyme and could account for the resumption of normal growth in G6PD deficient host cells. It is unclear whether the parasite enzyme can enable the host cell to resist oxidative stress as normal cells do. To answer this question, P. falciparum was grown in vitro in: (a) normal red cells, (b) G6PD deficient red cells for one growth cycle only, (c) G6PD deficient cells for a minimum of five cycles. All groups were then challenged with acetylphenylhydrazine (APH) which served as an oxidative stress. Both G6PD (A-) and Mediterranean deficient types were studied. The results show a two-fold increase in resistance to oxidative stress by parasites adapted to G6PD-Mediterranean deficient host cells as compared to unadapted ones, but the parasite-red cell system remains 4 times more sensitive to APH than normal infected cells. In parasitized G6PD (A-) red cells, evidence of adaptation could be seen in the growth curves, but no detectable increase in resistance to APH was found in adapted parasites. It is concluded that the role of the parasite G6PD is not likely to be mainly related to oxidative stress resistance and therefore other functions of this enzyme should be investigated.

Effects of iron-, manganese-, or magnesium-deficiency on the growth and morphology of Euglena gracilis.

Iron-, manganese-, or magnesium-deficiency has been induced in Euglena gracilis. Each arrests cell proliferation, decreases the intracellular content of the deficient metal, and increases that of several other metals. Light and electron microscopy of stationary phase cells reveal that Fe-deficient (-Fe) cells are similar in size and shape to control organisms. Magnesium-deficient (-Mg) cells, however, are larger, and approximately 14% are multilobed, containing 2 to 12 lobes of equal size emanating from a central region. Individual (-Mg) cells and each lobe of multilobed cells contain a single nucleus. Manganese-deficient (-Mn) organisms are morphologically more heterogeneous than (-Fe) or (-Mg) cells. Most are spherical and larger than controls. Approximately 15% are multilobed but, unlike (-Mg) cells, contain lobes of unequal size with either zero, one, or several nuclei present in each. Nuclei of (-Mn) cells differ in size and shape from those of control, (-Fe), or (-Mg) cells. All three deficient cell types accumulate large quantities of paramylon. Other cytoplasmic structures, however, appear normal. Addition of Fe, Mn, or Mg to the respective deficient stationary phase cultures reverses growth arrest and restores normal morphology. The results suggest that Fe-, Mn-, and Mg-deficiencies affect different stages of the E. gracilis cell cycle.

The hydrogeology of the Gombe subcatchment, Benue Valley, Nigeria

The area of study, which is about 90 km 2, is underlain by five major stratigraphic units of Paleocene to Cretaceous age except for the Precambrian Basement Complex inlier which forms about 2.7% of the rocks present. Results of our investigation show that the Kerri-Kerri Formation is of aquifer type material but dry in the surveyed area. The Gombe Formation with its high percentages of silts is slightly permeable, whilst the Pindiga and Yolde Formations are essentially aquicludes, although the latter has scattered water-bearing horizons. Chemical analyses of borehole water indicate good quality water despite the differences in depth of sampling. Two groups of water emerged—sodium bicarbonate rich and sodium bicarbonate deficient types. Results of isotope hydrology suggest that the sodium deficient type water has similar characteristics to the waters from the middle zone aquifer of the Chad basin and deep aquifer of the Sokoto basin. The highest computer transmissivity value ( T) of 432 m 2/d and storage coefficient ( S) of 2.3 × 10 −3 in the subcatchment were for the Bima Formation. The Bima Formation is thus the best aquifer in the subcatchment. Since the available data show that the aquifer of the Bima Formation is gradually being over-developed, and the observed characteristics of a few boreholes in the Pindiga and Yolde Formations are encouraging, a detailed hydrogeological assessment of the other Formations in the Gombe subcatchment is recommended.