Normal pH Values Research Articles

Photosynthetic carbon acquisition in Sargassum henslowianum (Fucales, Phaeophyta), with special reference to the comparison between the vegetative and reproductive tissues.

The photosynthetic oxygen evolution characteristics were examined in both vegetative (blade) and sexual reproductive (receptacle) tissues of Sargassum henslowianum (Fucales, Phaeophyta) from the Shenao bay of Nanao Island, China, to establish the mechanism of photosynthetic acquisition of inorganic carbon (Ci) in this species. In natural seawater (pH 8.1, ca. 2.2 mM Ci), irradiance-saturated net photosynthetic rate (NPR) was greater by 25.3% in blade than receptacle, whereas dark respiratory rate (DR) was 2-fold higher in receptacle than blade. NPR at pH 8.1 was nearly saturated with the 2.2 mM Ci for both blade and receptacle. However, the values of the half-saturation constant for Ci were sharply increased at pH 9.0. NPR was significantly affected, but DR was remained unchanged, with the variation of the pH values in seawater. The data from the final pH value derived from the pH-drift experiments and the comparison between the measured and theoretically estimated photosynthetic rates suggested that both blade and receptacle were capable of acquiring HCO(3)(-) in seawater. The inhibitors experiments showed that a HCO(3)(-) dehydration mechanism mediated by external carbonic anhydrase activity occurred in both the blade and receptacle tissues of S. henslowianum. The proton buffer TRIS had no inhibitory effect on NPR at normal pH value in natural seawater (pH 8.1), but it significantly depressed NPR at pH 9.0. This suggested that proton transport occurred at the outside of the plasma membrane facilitated the operation of the carbon acquisition at pH 9.0. It was proposed that the strategy of photosynthetic carbon acquisition at higher pH would prevent the alga from the damage of over-excitation and photoinhibition in case of sunshine and calm water. We concluded that the blade and receptacle tissues of S. henslowianum have similar mechanism of acquisition of exogenous Ci from seawater to drive photosynthesis; yet they are differentiated more or less with the photosynthetic properties.

Formation and stability of oil-in-water nanoemulsions containing rice bran oil: in vitro and in vivo assessments

BackgroundNanoemulsions have practical application in a multitude of commercial areas, such as the chemical, pharmaceutical and cosmetic industries. Cosmetic industries use rice bran oil in sunscreen formulations, anti ageing products and in treatments for skin diseases. The aim of this study was to create rice bran oil nanoemulsions using low energy emulsification methods and to evaluate their physical stability, irritation potential and moisturising activity on volunteers with normal and diseased skin types.ResultsThe nanoemulsion developed by this phase diagram method was composed of 10% rice bran oil, 10% surfactants sorbitan oleate/PEG-30 castor oil, 0.05% antioxidant and 0.50% preservatives formulated in distilled water. The nanoemulsion was stable over the time course of this study. In vitro assays showed that this formulation has a low irritation potential, and when applied to human skin during in vivo studies, the nanoemulsion improved the skin's moisture and maintained normal skin pH values.ConclusionThe results of irritation potential studies and in vivo assessments indicate that this nanoemulsion has potential to be a useful tool to treat skin diseases, such as atopic dermatitis and psoriasis.

In vivo31P and13C NMR investigations ofRhodococcus rhodochrousmetabolism and behaviour during biotransformation processes

The strain Rhodococcus rhodochrous OBT18 was isolated from a water treatment plant used to decontaminate industrial effluents containing benzothiazole derivatives. Aims of the work are to study the central metabolism of this strain and more specifically its behaviour during biodegradation of 2-aminobenzothiazole. In vivo(13)C and (31)P NMR experiments showed that this strain contains storage compounds such as polyphosphates, glycogen and trehalose and produces biosurfactants containing trehalose as sugar unit. Trehalose can be synthesized after reversion of the glycolytic pathway. In vivo(31)P NMR experiments showed that energy metabolism markers such as the intracellular pH and the ATP concentration did not change during biotransformation processes when R. rhodochrous was exposed to potentially toxic compounds including iron complexes and (* )OH radicals. Also R. rhodochrous recovers the normal values of ATP and pH after anoxia/reoxygenation cycle very quickly. Rhodococcus rhodochrous carbon and energy metabolism is well adapted to different stresses and consequently to live in the environment where conditions are constantly changing. The results of this study can be used to understand the behaviour of this bacterium in natural environments but also in water treatment plants where iron and UV light are present.

Exhaled Breath Condensate pH in Adult Croatian Population Without Respiratory Disorders: How Healthy a Population Should Be to Provide Normative Data?

The aim of this study was to obtain preliminary exhaled breath condensate (EBC) pH values for healthy adult Croatian subjects, and to evaluate criteria for defining respiratory health of population providing normal EBC pH values in epidemiologic studies. In 109 adults without a history of lower airway symptoms (AS), four groups were described by narrowing the definition of "health" down to 1) without lower AS; 2) without lower and upper AS; 3) without AS, with normal FEV(1) and bronchial normoreactivity; 4) without AS, with normal FEV(1), bronchial normoreactivity, normal total IgE, and with negative skin prick test. Median EBC pH values did not differ between the groups (7.72, 7.73, 7.73, 7.73), but as health criteria got stricter, we observed a slight, nonsignificant increase in minimal pH values (6.95, 7.10, 7.20, 7.37). Median EBC pH values with interquartile range in the total sample (7.72; 7.63 to 7.76) were within the range previously reported by other authors. They did not differ regarding sex, smoking habit and atopic status, and were not associated with age, FEV(1) or total IgE. The non-significant trend in EBC pH observed with stricter criteria of respiratory health and atopic status indicates the need for further research on criteria for defining healthy population in a larger sample.

Chemical composition, palatability and physical characteristics of venison from farmed deer

ABSTRACTThe quality of venison from farmed deer were evaluated based on chemical composition, palatability scores, W‐B shear force, ultimate pH, and color. The samples of venison were derived from javan rusa (Cervus timorensis russa), moluccan rusa (Cervus timorensis moluccensis), sambar (Cervus unicolor brookei), fallow (Dama dama) and imported red deer (Cervus elaphus). Moluccan rusa and red deer were fed grass. Javan rusa, sambar and fallow deer were fed concentrate. The venison obtained from grazing deer (grass‐fed) gave higher moisture content (75.3%) than concentrate‐fed or confinement‐raised deer (74.4%) and imported venison (70.62%). Fat content in venison shows some differences between muscles and species. The concentrate‐fed animals had a higher (P < 0.05) fat content in the venison than the grazing deer. Temperate deer (fallow and red deer) showed higher (P < 0.05) fat content than tropical deer (rusa and sambar deer). Venison obtained from concentrate‐fed deer showed normal ultimate pH values (pH ≤ 6.0) and more reddish in color than grass‐fed deer. The concentrate‐fed venison produced slightly higher (P > 0.05) palatability scores than grass‐fed venison. Feeding regimens (grass‐fed vs. concentrate‐fed) significantly (P < 0.05) influenced fat composition in the venison of farmed deer in this study.

Meat quality and intramuscular fatty acid composition of Sanfratellano and Haflinger foals

The goal of the trial was to evaluate meat quality, with an emphasis on intramuscular fatty acid composition, of Sanfratellano foals, compared to that from Haflinger foals,both slaughtered at 18 months of age. Thirty foals, half of Sanfratellano breed and half of Haflinger breed, naturally weaned at 7–8 months, were divided into two homogeneous groups at 15 months of age and fed a finishing diet based on polyphite hay and concentrate. The finishing period lasted three months. Sanfratellano foals showed higher slaughter weight ( P < 0.05) as well carcass weight ( P < 0.05) compared to Haflinger foals. Meat physical and proximate analyses did not discriminate the two groups. Normal pH values (5.6–5.7) measured at 4–6 day post mortem were recorded in meat from both groups. Shear force values accounted (range 55–58 N) for a favourable tenderness in both groups. The intramuscular fat level was low in both groups (<2.5%) supporting the healthy image of this meat. The proportion of linolenic acid was higher ( P < 0.01) in Haflinger meat than in Sanfratellano one, thus causing a higher ( P < 0.05) total n−3 fatty acid content. Overall meat from both groups showed a favourable repartition among saturated (36–37% total FAME’s), monounsaturated (33% total FAME’s) and polyunsaturated fatty acids (30–31% total FAME’s).

Normal 24-hour Ambulatory Esophageal pH Values in Koreans

Twenty-four-hour ambulatory esophageal pH monitoring is considered the gold standard for diagnosing gastroesophageal reflux disease. The aim of this study was to quantify normal distal esophageal acid parameters in healthy Koreans. Thirty healthy adults who were not on medication and were free from gastrointestinal symptoms were analyzed. Ambulatory esophageal acid (pH <4) exposure parameters were recorded at 5 cm above the lower esophageal sphincter. The 95th percentiles for reflux parameters assessed in the distal esophagus were as follows: percentage of total time with pH <4, 5.10%; percentage of upright time with pH <4, 7.88%; percentage of supine time with pH <4, 4.00%; number of reflux episodes, 62.7; number of reflux episodes with pH <4 for >5 minutes, 5.3; and the longest single acid-exposure episode, 21.3 minutes. Physiological gastroesophageal reflux occurs frequently in healthy Koreans. These data provide a reference range that could be utilized in studies involving Korean subjects.

Electrochemical microsensors for cutaneous surface analysis: Application to the determination of pH and the antioxidant properties of stratum corneum

Potentiometry and cyclic voltammetry were proposed as simple, reliable and non invasive methods for the simultaneous determination of pH and antioxidant properties of skin. Experiments were performed with microelectrodes just deposited on skin surface without any gel or water added. pH was measured by means of the zero current potential of a tungsten W/WO 3 sensor. A nerstian response was recorded in pH range 4 to 6 corresponding to the normal skin pH values. The global antioxidant capacity was deduced from the anodic charge passed during the plotting of cyclic voltammograms on platinum or gold microelectrodes. Comparing the half wave or peak potentials of these curves with those recorded for experiments performed in aqueous solution, the main hydrophilic antioxidants species were detected, i.e. ascorbic acid, uric acid and glutathione. This relatively easy-to-use analytical method made it possible to follow in real time the efficiency of topic treatment as well as to study the influence of oxidative stress.

Severe hyperlactatemia with normal base excess: a quantitative analysis using conventional and Stewart approaches.

IntroductionCritically ill patients might present complex acid–base disorders, even when the pH, PCO2, [HCO3-], and base excess ([BE]) levels are normal. Our hypothesis was that the acidifying effect of severe hyperlactatemia is frequently masked by alkalinizing processes that normalize the [BE]. The goal of the present study was therefore to quantify these disorders using both Stewart and conventional approaches.MethodsA total of 1,592 consecutive patients were prospectively evaluated on intensive care unit admission. Patients with severe hyperlactatemia (lactate level ≥ 4.0 mmol/l) were grouped according to low or normal [BE] values (<-3 mmol/l or >-3 mmol/l).ResultsSevere hyperlactatemia was present in 168 of the patients (11%). One hundred and thirty-four (80%) patients had low [BE] levels while 34 (20%) patients did not. Shock was more frequently present in the low [BE] group (46% versus 24%, P = 0.02) and chronic obstructive pulmonary disease in the normal [BE] group (38% versus 4%, P < 0.0001). Levels of lactate were slightly higher in patients with low [BE] (6.4 ± 2.4 mmol/l versus 5.6 ± 2.1 mmol/l, P = 0.08). According to our study design, the pH, [HCO3-], and strong-ion difference values were lower in patients with low [BE]. Patients with normal [BE] had lower plasma [Cl-] (100 ± 6 mmol/l versus 107 ± 5 mmol/l, P < 0.0001) and higher differences between the changes in anion gap and [HCO3-] (5 ± 6 mmol/l versus 1 ± 4 mmol/l, P < 0.0001).ConclusionCritically ill patients may present severe hyperlactatemia with normal values of pH, [HCO3-], and [BE] as a result of associated hypochloremic alkalosis.

Effect of rearing system and mixing at loading on transport and lairage behaviour and meat quality: comparison of outdoor and conventionally raised pigs

The effect of raising pigs outdoors or conventionally in a barren environment was investigated with respect to behaviour during a 3 to 4 h journey and a 2 h lairage, blood chemistry at slaughter and meat quality characteristics. Pigs were either kept in farm pen groups or were mixed at loading and kept in the groups, so formed, until slaughter. Non-mixed outdoor pigs settled more quickly during transport and lay down to a greater extent at the end of the journey and lairage period compared with conventionally raised pigs. Mixing led to fewer pigs sitting and lying during transport for conventionally raised pigs, where nearly 80% were still standing at the end of the journey. Mixing had no effect on pig posture in the lairage. Outdoor pigs were less aggressive than conventionally raised pigs especially during lairage and had a lower frequency of unacceptable skin damage in the rear and shoulder area. Aggressive interactions were almost exclusively confined to mixed groups and occurred mainly between pigs from different farm pens, i.e. between unfamiliar animals. Mixing at loading led therefore to higher levels of unacceptable skin damage. Cortisol concentrations in slaughter blood were not affected by rearing system or mixing, but mixed, conventionally raised pigs had higher plasma creatine kinase (CK) activities than non-mixed ones (1132 v. 761 U/l, respectively, P < 0.05). Outdoor pigs had similar CK activities, irrespective of mixing (682 and 771 U/l for mixed and non-mixed, respectively). Muscle pH early post mortem was highest in outdoor pigs and muscle temperature lower, but no pig showed pH values below 6.0. Ultimate pH values were both higher (Semimembranosus (S)) and lower (Semispinalis capitis (SC)) than in conventionally raised pigs, and outdoor pigs tended to have a lower frequency of higher than normal pH values. Internal reflectance (MQM) values in Biceps femoris (BF) were highest in outdoor pigs but the incidence of pale, soft and exudative (PSE) meat was low, varying between 0% and 1% for experimental groups. In general, the effects of rearing system and mixing on meat quality measurements taken early post mortem or the day after slaughter were slight, but the trends seen support the CK results, and show that conventionally raised pigs may have found mixing pre-slaughter to be more physically stressful than outdoor pigs did.

Normal Ambulatory 24-Hour Esophageal pH Values in Koreans -A Multicenter Study-

Ambulatory 24-hr esophageal pH monitoring is considered the gold standard for diagnosing gastroesophageal reflux disease. The aim of this study was to establish normal values for gastroesophageal acid exposure in healthy Koreans. Fifty healthy volunteers (24 males and 26 females; mean age, 45 yr) without reflux symptoms and without reflux esophagitis or hiatal hernia on upper endoscopy underwent ambulatory 24-hr esophageal pH monitoring after esophageal manometry. The 95th percentiles for the reflux parameters were: the percent total time pH <4, 3.7%; the percent upright time pH <4, 5.7%; the percent supine time pH <4, 1.0%; the number of reflux episodes with pH <4, 76.5; the number of reflux episodes with pH <4 for >5 min, 1.5; the duration of the longest episode, 12.5 min; and the composite score, 14.2. Age and gender were not associated with any of the pH parameters. In conclusion, physiological gastroesophageal reflux occurs in healthy Koreans. These normal esophageal pH values will provide reference data for clinical and research studies in Korea.

Consequences of Intrauterine Acidosis for Early Morbidity of Term Newborn Infants

The study was designed to evaluate early morbidity of term newborn infants according to the umbilical artery pH and umbilical artery base excess. The study was based on the 1 173 infants who were born at term in the study period in 1997 with a UA-pH below 7.20. A retrospective review was carried out of maternal and infant records during the study period. All data were evaluated using SPSS for windows. Apgar-values and UA-pH correlated closely, the rate of 1-minute Apgar scores < 7 increased with decreasing UA-pH. The rate of 5-minute Apgar score < 7 increased strongly with UA-pH below 7.00. The study showed how closely UA-pH values are related to UA-BE values. Of newborns with UA-BE values of 0 to - 9 mmol / l 7 % had 1-minute Apgar scores < 7, 53 % of cases with UA-BE </= - 17 mmol / l were recorded with 1-minute Apgar scores < 7. It was demonstated that low Apgar scores - as well as treansfer rates - increase if UA-pH falls below 7.1 and the base excess at the same time is below - 10 mmol / l. The aim of modern obstetrics should be to promote the birth of vital children with normal pH values.

“SMART” Drug Delivery Systems: Double-Targeted pH-Responsive Pharmaceutical Nanocarriers

To develop targeted pharmaceutical carriers additionally capable of responding to certain local stimuli, such as decreased pH values in tumors or infarcts, targeted long-circulating PEGylated liposomes and PEG-phosphatidylethanolamine (PEG-PE)-based micelles have been prepared with several functions. First, they are capable of targeting a specific cell or organ by attaching the monoclonal antimyosin antibody 2G4 to their surface via pNP-PEG-PE moieties. Second, these liposomes and micelles were additionally modified with biotin or TAT peptide (TATp) moieties attached to the surface of the nanocarrier by using biotin-PE or TATp-PE or TATp-short PEG-PE derivatives. PEG-PE used for liposome surface modification or for micelle preparation was made degradable by inserting the pH-sensitive hydrazone bond between PEG and PE (PEG-Hz-PE). Under normal pH values, biotin and TATp functions on the surface of nanocarriers were "shielded" by long protecting PEG chains (pH-degradable PEG(2000)-PE or PEG(5000)-PE) or by even longer pNP-PEG-PE moieties used to attach antibodies to the nanocarrier (non-pH-degradable PEG(3400)-PE or PEG(5000)-PE). At pH 7.4-8.0, both liposomes and micelles demonstrated high specific binding with 2G4 antibody substrate, myosin, but very limited binding on an avidin column (biotin-containing nanocarriers) or internalization by NIH/3T3 or U-87 cells (TATp-containing nanocarriers). However, upon brief incubation (15-30 min) at lower pH values (pH 5.0-6.0), nanocarriers lost their protective PEG shell because of acidic hydrolysis of PEG-Hz-PE and acquired the ability to become strongly retained on an avidin column (biotin-containing nanocarriers) or effectively internalized by cells via TATp moieties (TATp-containing nanocarriers). We consider this result as the first step in the development of multifunctional stimuli-sensitive pharmaceutical nanocarriers.

Acid–base metabolism: implications for kidney stosne formation

The physiology and pathophysiology of renal H+ ion excretion and urinary buffer systems are reviewed. The main focus is on the two major conditions related to acid-base metabolism that cause kidney stone formation, i.e., distal renal tubular acidosis (dRTA) and abnormally low urine pH with subsequent uric acid stone formation. Both the entities can be seen on the background of disturbances of the major urinary buffer system, NH3+ <--> NH4+. On the one hand, reduced distal tubular secretion of H+ ions results in an abnormally high urinary pH and either incomplete or complete dRTA. On the other hand, reduced production/availability of NH4+ is the cause of an abnormally low urinary pH, which predisposes to uric acid stone formation. Most recent research indicates that the latter abnormality may be a renal manifestation of the increasingly prevalent metabolic syndrome. Despite opposite deviations from normal urinary pH values, both the dRTA and uric acid stone formation due to low urinary pH require the same treatment, i.e., alkali. In the dRTA, alkali is needed for improving the body's buffer capacity, whereas the goal of alkali treatment in uric acid stone formers is to increase the urinary pH to 6.2-6.8 in order to minimize uric acid crystallization.

Disruption of the SLC26A3-mediated anion transport is associated with male subfertility

Male subfertility in congenital chloride diarrhea (CLD) was possible after identification of expression of an epithelial Cl-/HCO3- exchanger SLC26A3 in the male reproductive tract and by the observation that adult men with CLD had very few children. A prospective clinical and laboratory study among eight adult Finnish men with CLD revealed constant oligoasthenoteratozoospermia but normal spermatogenesis, high chloride and low pH in seminal plasma, and three spermatoceles, suggesting that male subfertility is a clinical manifestation of CLD and could be caused by an analogous defect in the epithelial Cl-/HCO3- and water transport, as described for the CLD intestine.

The association of renal tubular acidosis and cyanotic congenital heart disease

Although late survival has been occasionally reported for patients with cyanotic congenital heart disease (CCHD), the complexity of the cardiac malformations and the complications of cyanosis prove often lifethreatening at an early age. 1 It has been documented that chronic cyanosis affects renal glomerular structure and function, causing progressive glomerulopathy with eventual proteinuria. 2,3 Adverse effects of chronic hypoxia on renal tubular function have been less frequently documented. 4,5 Secondary renal tubular acidosis (sRTA) seems to be an acquired complication in patients with chronic cyanosis. The aim of this study was to evaluate the association of CCHD and renal tubular acidosis in a Guatemalan population. Patients and Methods Seventy-three of 110 patients with cyanosis (study group) with congenital heart disease were selected on the basis of an arterial oxygen saturation less than 80%. In these patients, arterial pH and blood gas values, as well as plasma anion gap (PAG) and urinary anion gap (UAG) were measured to evaluate the origin of metabolic acidosis. Patients with diarrhea in the previous 15 days or receiving prolonged treatment with diuretics or laxatives were also excluded. The diagnosis of sRTA should be suspected in all patients with a normal PAG and hyperchloremic metabolic acidosis. Differentiation of sRTA from other metabolic disorders is facilitated by the determination of the UAG. A UAG greater than 0 is indicative of an acidification defect at the distal tubular level (distal sRTA), whereas a UAG less than 0 suggests the presence of gastrointestinal or renal loss of bicarbonate (proximal sRTA). Fifty-six of the 73 patients included in the study (77%) had metabolic acidosis (plasma bicarbonate 22 mmol/L); of these, 48 (86%) also had a normal PAG (sRTA group). The remaining 17 patients (23%) had normal arterial pH and blood gas values (reference group). Metabolic acidosis originated from the distal renal tubule (UAG 0) in 39 patients (81%, distal sRTA) and from the proximal tubule (UAG 0) in 9 patients (19%, proximal sRTA; Figure 1 and Table 1). Patients with distal renal tubular acidosis were significantly older than patients in th e reference group (P .05). Differences in other variables analyzed in this study, such as patient nutritional status, altitude (meters above sea level), and renal function, were not significant. Ten patients with sRTA who underwent surgical repair of their congenital heart disease with elimination of cyanosis (mean postoperative arterial oxygen saturation increased from 70.3% 7.94% to 95.3% 3.19%) were evaluated at 48 postoperative hours. They had a normal arterial pH and blood gas profile .

Laktobazillen-Schutzsystem bei Schwangeren - effiziente Vermeidung von Frühgeburten durch Früherkennung von Störungen

The most frequent cause of preventable early premature births (< 32 + 0 gestational weeks) is urogenital tract infection (UTI). Screening for UTI and Chlamydia are now standard examinations. Detection of ascending genital infections, especially bacterial vaginosis, plays an ever-increasing role. Lactobacilli, which produce, e. g., lactic acid, H2O2, biosurfactants and coaggregation molecules, are particularly important for the vaginal biosystem. Some evaluations suggest that early diagnosis and therapy within this "lactobacilli-protection system" apparently leads to better results in the prevention of prematurity. Our screening recommendations for the pregnant patient comprise vaginal pH measurements both at the regular prenatal care visits and particularly the self measurement within the framework of our Self-Care Program. 140 participating women were questioned for a second time. The data were compiled by the patients themselves. Due to elevated pH values, 21% of the women consulted their physician earlier than foreseen. Diagnoses: In 46% there was a disturbance of the vaginal milieu, in 4% bacterial vaginosis, in 33% Candida infection and in 21% "everything was OK". In spite of self-measured normal pH values in 25% of the patients the physician diagnosed the following: 25% disturbance of the vaginal milieu, 7% bacterial vaginosis, 32% infection with other bacteria (mainly Streptococci) and 50% Candida infection. Elevated pH values (measured by the patient) seem to indicate much more often a disturbance of vaginal milieu rather than an already existing bacterial vaginosis. Further investigations are necessary. The chances to treat vaginal disturbances--before a concrete infection is diagnosed--seem to be better for participants in the Self-Care Program.

The Role of Esophageal pH Monitoring in Symptomatic Patients on PPI Therapy

Ambulatory pH monitoring while on therapy is often recommended in gastroesophageal reflux disease (GERD) patients with continued symptoms. However, to date, little data exist to justify this indication. To assess the role of pH monitoring in symptomatic patients despite aggressive therapy with typical or extra esophageal GERD. Retrospective review of 2,291 ambulatory pH tracings (1999-2003) identified subgroup of studies performed on proton pump inhibitor (PPI) therapy. Patients with prior fundoplication or Barrett's esophagus were excluded. Patients grouped on predominant presenting GERD symptoms: typical (heartburn and regurgitation) or extra esophageal (chest pain, cough, hoarseness, sore throat, shortness of breath, asthma). The distribution of abnormal pH parameters in each group calculated and univariate analyses assessed the probability of abnormal pH in each group. Abnormal cutoff values traditionally used in clinical practice and more stringent cutoff values used to determine distribution of abnormality as a function of cutoff values. A total of 250 patients (mean age 54.3 yrs, 59% female) underwent pH monitoring on either daily (b.i.d.) or twice daily (q.d.) on PPI therapy: 115 (46%) with extra esophageal and 135 (54%) with typical GERD symptoms. Extra esophageal GERD patients were more likely to undergo pH monitoring on b.i.d. PPIs (OR = 2.7; 95% CI = 1.6-4.4; p < 0.01). 52 (93%) of typical and 74 (99%) of extra esophageal GERD patients on b.i.d. PPIs tested normal. The odds of a normal pH values were 11 times higher for patients on b.i.d. PPIs (OR = 11.4; 95% CI = 4.3-30.1, p < 0.01) than those on q.d. PPIs. 1) The likelihood of an abnormal esophageal pH for symptomatic GERD patients on b.i.d. PPI is very small. 2) In this group of patients failing b.i.d. PPIs causes other than GERD should be sought.

Limited Role of pH Monitoring in Nonresponders to Twice-Daily PPI Therapy

Proton-pump inhibitors (PPIs) have revolutionized our approach to both the diagnosis and treatment of gastroesophageal reflux disease (GERD). Although a trial of empirical PPI therapy has become standard for patients with suspected GERD or related extraesophageal complications, an emerging subset of patients are nonresponders. In this retrospective analysis, researchers examined the value of pH monitoring in 250 symptomatic patients at Cleveland Clinic who underwent pH monitoring while taking a PPI (once or twice daily). Normal pH values were defined according …

AMANTADINE IN CHRONIC GRANULOMATOUS DISEASE

Chronic granulomatous disease (CGD) is a rare genetically determined immunodeficiency. Neutrophils from CGD patients show a defective killing of phagocytosed fungi and bacteria, due not only to an impairment in oxidative burst, but also to absence of normal pH value within phagocytic vacuole following phagocytosis. Because a weak base such as amantadine could potentially reverse these pH abnormalities, the authors used this drug to treat 2 CGD patients. They observed modifications of both phagosomal pH and killing activity on their neutrophils compared to those of healthy controls. Since the drug has been employed, the patients have not developed new infections, suggesting a role of amantadine as a part of CGD prophylactic regimen. These results suggest the opportunity of testing the drug in larger studies.