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PubMed1983

Milk alkali syndrome. Does it exist and can it be differentiated from primary hyperparathyroidism?

Four patients with milk-alkali syndrome (MAS) presented with many of the characteristics of primary hyperparathyroidism including hypercalcemia, low or normal serum phosphorus levels, normal or increased urinary calcium levels, and inappropriately high or elevated serum parathyroid hormone levels. These laboratory findings differ from those classically described in MAS, i.e., hypercalcemia without hypercalciuria and a normal or high plasma phosphate level. Because the serum calcium level failed to return to normal after two weeks of hydration and a low calcium diet, and because of the inability to distinguish this syndrome from primary hyperparathyroidism, two of the four patients underwent neck exploration. Four normal parathyroid glands were histologically proven in each, and at autopsy in a third patient, there was no evidence of parathyroid hyperplasia or adenoma. Hypercalcemia eventually resolved in all patients with a low-calcium diet for as long as six months. Of the several features of MAS, hypercalcemia, alkalosis in the presence of azotemia, a history of increased calcium and alkali intake, and a response to dietary calcium restriction are helpful in differentiating this syndrome from primary hyperparathyroidism. Laboratory tests in patients with MAS may be confusing and the return to normocalcemia in response to a calcium deficient diet may be delayed.

Aged↗
PubMed1992

Subconjunctival injection of purified blood mononuclear cells into alkali-injured rabbit eyes.

Monocytes transform into tissue macrophages that scavenge necrotic debris from wounds but also release substances stimulatory to fibroblasts. In an effort to encourage the healing process, monocytes, purified from rabbit blood, were injected subconjunctivally 1 or 2 days and 6 or 7 days after alkali injury to the rabbit eye. The injected monocytes failed to alter the course of the alkali-injured eyes. Specifically, the incidence of corneal ulceration in the experimental group was not statistically different from that of the control group. A byproduct of this study was a presentation of the technique to purify platelet-free mononuclear leukocytes from rabbit peripheral blood.

Animals↗
PubMed2004

Milk-alkali syndrome in pregnancy.

BACKGROUND: Severe hypercalcemia, a potentially life-threatening medical emergency, is rare in pregnancy. CASE: We report a 32-year-old woman presenting early in the second trimester with severe hypercalcemia (total calcium 22 mg/dL), alkalosis, and acute renal insufficiency resulting from excessive ingestion of calcium carbonate-containing antacid for gastroesophageal reflux. The patient was treated with aggressive hydration and furosemide, and received 1 dose of intravenous etidronate, leading to short-term symptomatic hypocalcemia. To our knowledge, this is the third reported case of milk-alkali syndrome in pregnancy. CONCLUSION: Milk-alkali syndrome is an uncommon cause of hypercalcemia in pregnancy. Intravenous hydration with saline should be the cornerstone of treatment, reserving bisphosphonates for selected cases.

Acute Kidney Injury↗
PubMed2006

Milk-alkali syndrome presenting as acute renal insufficiency during pregnancy.

BACKGROUND: Gastroesophageal reflux is common during pregnancy. Hypercalcemia from overuse of antacids can lead to complications, including the milk-alkali syndrome. CASE: A multiparous patient, at 35 weeks of gestation, was admitted to evaluate an unexplained increase in her serum creatinine (0.6 mg/dL to 1.4 mg/dL). She was normotensive and asymptomatic. Her serum calcium was 16.2 mg/dL. She reported significant gastric reflux symptoms and was taking a calcium-based antacid at high doses. She was treated with aggressive hydration. Her calcium and renal function normalized with no further complications. CONCLUSION: Overuse of calcium-containing medications can cause milk-alkali syndrome. Vigorous hydration is generally adequate treatment, and education regarding calcium intake is important to prevent occurrence.

Antacids↗
PubMed1976

Isolation and composition of an alkali-soluble glucan from the cell walls of Saccharomyces cerevisiae.

An alkali-soluble glucan was obtained from the cell walls of Saccharomyces cerevisiae NCYC1109 and baker's yeast by extraction with cold, dilute sodium hydroxide under nitrogen. The glucan, which represented approximately 20% of purified glucan was homogeneous and was shown to be free from contamination by other cell-wall polysaccharides by ultracentrifuging, gel filtration and electrophoresis. In addition to glucose, the glucan contained traces of mannose and nitrogen, but no hexosamine. Structural analyses revealed the presence of 80-85% (1 leads to 3)-beta-D linkages, 8-12% (1 leads to 6)-beta-D linkages and 3-4% branched residues linked through C-1, C-3 and C-6. The molecular weight of the glucan was estimated to be about 250000. Electron-microscopic examination of the cell walls after alkali extraction showed that an amorphous surface layer had been removed revealing numerous bud scar structures.

Cell Fractionation↗
PubMed2002

Magnetic slowing down of spin relaxation due to binary collisions of alkali-metal atoms with buffer-gas atoms.

We report the first studies of magnetic decoupling of the spin relaxation of alkali-metal atoms due to binary collisions with buffer gases. When binary collisions are the dominant relaxation mechanism, the relaxation and its magnetic decoupling are well described by the S-damping rate Gamma(SD) due to the spin-rotation interaction gammaN.S, the spin exchange rate Gamma(EX) for collisions between alkali atoms, and a new "Carver rate" Gamma(C), due to the pressure-shift interaction deltaAI.S, which can substantially broaden the magnetic decoupling curve while having no influence on the zero-field rates.

Journal Article↗
PubMed2002

Cation mass dependence of the nearly constant dielectric loss in alkali triborate glasses.

Electrical ac conductivity measurements on alkali triborate glasses ( M2O x 3B2O3, M = Li, Na, K, and Rb) were performed at temperatures down to 8 K and frequencies up to 1 GHz. All samples show a nearly constant dielectric loss (NCL), at the limit of high frequencies and/or low temperatures. The magnitude of the NCL is found to decrease as m(-1/3) with increasing alkali ion mass m. This quantitative result for the NCL, closely related to the mean-square displacement of ions, indicates that the origin of the NCL might be related to vibrational relaxation of the ions in the anharmonic potentials that cage them, and the cage is decaying very slowly with time.

Journal Article↗
PubMed2003

New mixed alkali effect in the ac conductivity of ion-conducting glasses.

We have determined the first wide-range conductivity spectra of a mixed alkali glass system, extending from 10(-3) Hz to 1.3 THz. We report on a new mixed alkali effect in the ac conductivity that is evident even if the low-frequency contributions (linked to hopping motions of the mobile cations) are removed from the experimental spectra. From our results we conclude that the nonhopping contributions to the ac conductivity involve both the mobile ions and the glassy network.

Journal Article↗
PubMed2005

Internal friction and vulnerability of mixed alkali glasses.

Based on a hopping model we show how the mixed alkali effect in glasses can be understood if only a small fraction c(V) of the available sites for the mobile ions is vacant. In particular, we reproduce the peculiar behavior of the internal friction and the steep fall ("vulnerability") of the mobility of the majority ion upon small replacements by the minority ion. The single and mixed alkali internal friction peaks are caused by ion-vacancy and ion-ion exchange processes. If c(V) is small, they can become comparable in height even at small mixing ratios. The large vulnerability is explained by a trapping of vacancies induced by the minority ions. Reasonable choices of model parameters yield typical behaviors found in experiments.

Journal Article↗
PubMed2006

"Textbook" adsorption at "nontextbook" adsorption sites: halogen atoms on alkali halide surfaces.

Density-functional theory and second order Møller-Plesset perturbation theory calculations indicate that halogen atoms bond preferentially to halide substrate atoms on a series of alkali halide surfaces, rather than to the alkali atoms as might be anticipated. An analysis of the electronic structures in each system reveals that this novel adsorption mode is stabilized by the formation of textbook two-center three-electron covalent bonds. The implications of these findings to, for example, nanostructure crystal growth, are briefly discussed.

Journal Article↗
PubMed1967

Sodium absorption by barley roots: its mediation by mechanism 2 of alkali cation transport.

When barley roots absorb Na(+) at concentrations ranging from 1 to 50 mm, in the presence of low concentrations of Ca(2+) and K(+), absorption of Na(+) is mediated by carrier mechanism 2 of alkali cation transport, mechanism 1 being unavailable for Na(+) transport under these conditions. The absorption isotherm depicting the rate of Na(+) absorption as a function of the external Na(+) concentration, over the 1 to 50 mm range of concentrations, shows several inflections. This stepwise response occurs whether Cl(-) or SO(4) (2-) is the counterion, but actual rates of Na(+) absorption are lower in the latter case.When the concentration of Na(+) is 50 mm, and the concentration of either K(+) or Ca(2+) is increased from nil to 50 mm, the rate of absorption of Na(+) is diminished not as a smooth function of increasing concentrations of the interfering ions but stepwise. Similarly, when the concentration of K(+) is 50 mm, and the concentration of either Na(+) or Ca(2+) is increased from nil to 50 mm, the rate of absorption of K(+) is diminished not as a smooth function of increasing concentrations of the interfering ions but stepwise.Together, this evidence supports the previous conclusion to the effect that mechanism 2 of alkali cation transport possesses a spectrum of carrier sites with different ionic affinities.When both K(+) and Na(+) are presented at equivalent concentrations over the 1 to 50 mm range, mechanism 2 transports Na(+) almost exclusively, and mechanism 1 K(+) almost exclusively. These findings support previous conclusions to the effect that the active sites of mechanism 2 have higher affinity for Na(+) than for K(+), whereas the reverse is true for mechanism 1.

Journal Article↗
PubMed1988

A novel human myosin alkali light chain is developmentally regulated. Expression in fetal cardiac and skeletal muscle and in adult atria.

We have isolated cDNA recombinant phages encoding the embryonic isoform of the myosin alkali light chain (MLC1emb) from a human fetal skeletal muscle library. The cDNA clones were detected by their weak cross-hybridization to a human MLC1F and MLC3F cDNA clone. Nucleotide sequence analysis of the complete cDNA (GT14) revealed an open reading frame for 197 amino acids. The derived protein sequence constitutes the first structural information on this myosin isoform of any organism. Remarkable structural similarities to other alkali MLC polypeptides, particularly to those of the slow-muscle type, are evident. Under conditions of high stringency, the GT14 clone hybridized to an abundant mRNA species in fetal ventricular muscle and adult atrial muscle, whereas in fetal skeletal muscle only a very weakly hybridizing mRNA component was detected. These mRNAs were indistinguishable by size and the thermal stability of their hybrids formed with the DNA insert of clone GT14. We therefore conclude that identical mRNA is expressed in these tissues, presumably transcribed from the same gene. According to its pattern of mRNA expression, the novel MLC isoform described here was designated as "embryonic and atrial myosin light chain" (MLC1emb/A) in reference to its developmental stage-specific and tissue-specific appearance in embryonic skeletal muscle, fetal ventricle and adult atrium.

Adult↗
PubMed2004

Efficacy of early systemic betamethasone or cyclosporin A after corneal alkali injury via inflammatory cytokine reduction.

PURPOSE: To evaluate the effects of early systemic administration of betamethasone or cyclosporin A (CsA) on inflammatory cytokine expression and corneal damage after alkali injury. METHODS: Sixty-five Wistar rat corneas injured with 1N NaOH were divided into three groups: untreated, betamethasone-treated and CsA-treated. Both agents were administered systemically and daily during the first 7 days after injury. Interleukin (IL)-1alpha, -6 and -8 concentrations in the injured corneas were measured with ELISA at 2, 4 and 7 days after injury. Corneal damage was evaluated by scoring clinical findings. RESULTS: In untreated injured corneas, IL-1alpha, -6 and -8 were markedly elevated during the 7-day period following injury. Both betamethasone and CsA significantly suppressed IL-1alpha and IL-8 at day 4. Only betamethasone significantly suppressed IL-6 at days 4 and 7. Both agents significantly reduced corneal opacity at day 4. CONCLUSION: Early systemic administration of betamethasone or CsA after alkali injury may be of benefit by suppressing inflammatory cytokine expression in the cornea.

Animals↗
PubMed2005

Effect of different irrigating solutions on aqueous humour pH changes, intraocular pressure and histological findings after induced alkali burns.

PURPOSE: To evaluate the effects of hypo-osmolar tap water and isotonic saline solution on the intracameral pH, intraocular pressure and histological changes in alkali burned rabbit eyes. METHODS: Four groups of four rabbit corneas each were burned with 2 N sodium hydroxide, and then rinsed with 0.5 l or 1.5 l of saline solution or tap water, respectively. Changes in pH were monitored with an intracameral microelectrode. Intraocular pressure (IOP) was monitored by a transducer placed in the vitreous cavity. After enucleation, histology was performed. RESULTS: The pH increased after 1.5 min following alkali application. Irrigation with different solutions affected the maximum pH levels reached. Following the tap water rinse, the maximum rise was significantly lower than after the saline solution rinse. The maximum rise following rinsing with 1.5 l of tap water showed a significant delay. The increase in IOP was 23 +/- 10 mmHg without differences between the groups; the original pressure was recovered after 18 +/- 9 min. Histology of the eyes revealed a significant oedema in all corneas. Other ocular structures appeared unchanged. CONCLUSIONS: The hypo-osmolarity of tap water led to remarkable corneal oedema. Enlargement of the diffusion barrier and intracorneal dilution inhibit elevated intracameral pH levels. The difference in maximum pH levels reached may influence the degree of subsequent intraocular structure injury. Therefore, the use of iso-osmolar saline solution proves to be less efficacious than tap water as an irrigation agent for ocular burns.

Animals↗
PubMed1989

Convex curvatures of alkaline elution profiles of DNA from human cells irradiated with 405 nm UVA: evidence for induction of slowly developing alkali-labile sites.

The alkaline (pH 12.1) elution profiles of DNA from human P3 cells exposed to monochromatic 405 nm UVA radiation deviate from exponential: on a logarithmic plot of eluted fraction of DNA vs time of elution, the rate of elution accelerates for the first 6 h. Following this period, the profiles become exponential. In contrast, the elution profiles of DNA after 520 nm green light or ionizing radiation exposures (x- and gamma rays, and fission spectrum neutrons) are always strictly exponential, evidence that the convex profiles were not due to an artifact caused by elution technique. Holding the DNA at pH 12.1 for 6 h after 405-nm exposures before initiating elution resulted in profiles that were close to exponential, with slopes similar to the final slopes observed following the 6-h elution period in the original experiments. This is evidence that some DNA breaks develop slowly during the first 6 h of elution, as a result of exposure to alkali. Therefore, the DNA lesions induced by 405-nm light as measured by the alkaline elution technique are apparently heterogeneous and include a major class of alkali-labile sites that develop slowly during incubation at pH 12.1. Convex profiles also occur following exposure of the cells to visible light at 434 and 512 nm.

DNA Damage↗
PubMed1987

The behaviour of corneal epithelium following a standardized alkali wound.

The short and long-term healing of the rabbit corneal epithelium was studied after a standardized alkali wound. The wound was inflicted by applying a round filter paper, 5.5 mm in diameter, soaked in 1 N NaOH, for 60 seconds on the central cornea. The wound size and intensity was chosen not to cause melting and perforation, and not to cause vascular ingrowth. n-Heptanol corneal wounds of the same size were used as control. The eyes were followed for 8 weeks. Two phases of epithelial healing were discerned. The initial healing phase lasted 48 h during which the would was completely resurfaced. In spite of the more extensive tissue damage caused by alkali, the initial epithelial healing rate was faster than in n-heptanol wounds. The late healing phase consisted of recurrent epithelial break down, sometimes seen preceded by epithelial blister formation. Four weeks after trauma the state of epithelial healing was at its worst.

Alcohols↗
PubMed1975

Renal function in sheep during infusion of alkali metal ions into the renal artery.

1. The effect on renal function of 1 M solutions of LiCl, NaCl, KCl, RbCl and CsCl and 3 M-NaCl infused close-arterially to the kidney for 10 min at 0-7ml./min has been studied in nine experiments on four unilaterally nephrectomized sheep. The levels of flow, electrolyte concentration and electrolyte excretion in the urine were measured before, during and for 50 min after the infusions. 2. The infusion of 1-M-NaCl produced little change in urine flow and composition whereas 3 M-NaCl resulted in relatively small increases in urine flow and sodium excretion. 3. The infusion of lithium, potassium, rubidium and caesium resulted in marked increases in urine flow, urinary sodium concentration and excretion, urinary potassium excretion and osmolal clearance while the urinary potassium concentration decreased. 4. Changes in urine flow and urinary pH during the infusions of all the alkali ions except sodium were consistent with increased urinary bicarbonate excretion. 5. The osmolal clearance was increased by the infusion of lithium, potassium, rubidium and caesium, but equivalent increases in the rate of solutefree water reabsorption did not occur. 6. The infusion of caesium resulted in a depression of the glomerular filtration rate (G.F.R.) which was not observed when the other alkali ions were infused. 7. The effects of lithium, potassium and rubidium on urine flow and composition were rapid in onset and the residual effects on these ions, on cessation of infusion, were relatively short. The effects on caesium were slow in onset and prolonged in duration. 8. It was concluded that lithium, potassium, rubidium, and caesium altered urine flow and electrolyte excretion by acting upon common mechanisms which were predominantly intra-renal and located in the proximal segment of the nephron.

Aminohippuric Acids↗
PubMed1996

Photoinduced Chemical Dynamics of High-Spin Alkali Trimers

Nanometer-sized helium droplets, each containing about 10(4) helium atoms, were used as an inert substrate on which to form previously unobserved, spin-3/2 (quartet state) alkali trimers. Dispersed fluorescence measurements reveal that, upon electronic excitation, the quartet trimers undergo intersystem crossing to the doublet manifold, followed by dissociation of the doublet trimer into an atom and a covalently bound singlet dimer. As shown by this work, aggregates of spin-polarized alkali metals represent ideal species for the optical study of fundamental chemical dynamics processes including nonadiabatic spin conversion, change of bonding nature, and unimolecular dissociation.

Journal Article↗