Low’s syndrome

Other tubulopathies beyond the scope of this textbook include (1) hypomagnesemic hypercalciuric nephrocalcinosis ( congenital magnesium losing kidney ), (2) Gordon s syndrome (pseudohypoaldosteronism type II), (3) Lowe s syndrome (oculocerebral dystrophy), and (4) a series of disorders of the... 

Schoen, E. J.. Lowe s syndrome abnormalities in renal tubular function in combination with other congenital defects. Amcr. J. Med. 27, 781-792 (1959). 

Yoshida, H., Fukui, S., Yamashina, 1., Tanaka, T., Sakano, T., Usui, T., Shimotsuhi, T., Yabuuchi, H., Owada, M., and Kitagawa, T., Elevation of nucleotide pyrophosphatase activity in skin fibroblasts from patient with Lowe s syndrome. Biochem. Biophys. Res. Commun. 107, 1144-1150 (1982). 

Two hereditary diseases, Fanconi s syndrome and Lowe s syndrome, are associated with tubular acidosis. The Fanconi syndrome is a multiple proximal tubular defect including interference with amino acid, glucose, and phosphate reabsorption. In most cases there is also acidosis that is proximal in origin, but the mechanism of the acidosis is unknown. Lowe s syndrome, or oculocerebrorenal syndrome, is transmitted in a sex-linked recessive fashion. Affected patients have the Fanconi syndrome and also mental retardation, cataracts, glaucoma, and hypotonia. 

The urinary excretion, in cases of Lowe s syndrome, of undersulphated chondroitin 4-sulphate in the absence of other glycosaminoglycans has led to the suggestion that a disorder in the sulphation of glycosaminoglycans is etiologically implicated in this syndrome. ... 

Although rum ammonia levels are not routinely measured, it is a useful indicator of Reye s syndrome and should be monitored in newborns at risk of developing hyperammonemia Ammonia is produced in many analytically useful enzyme reactions and the ammonium ISE has been used as the base sensor in several enzyme electrodes (see next section). In addition to valinomycin, other antibiotics such as the nonactin homalogs and gramicidins also behave as ionophores. The nonactin homolo were originally studied for their ability to selectively bind potassiiun ions It was then discovered that ammonium ions were preferred over potassium ions, and the selectivity coefficient Knh+ = 0.12 was reported. Since ammonia is present at fairly low levels in serum, this selectivity is not sufficient to to accurately measure NH4 in the presence of K. An extra measure of selectivity can be gained by using a gas permeable membrane to separate the ammonia gas from the sample matrix... 

There is very little evidence relating to the role of ROMs in cholestatic liver disease. Serum selenium and glutathione peroxidase activity are decreased in humans with intrahepatic cholestasis of pregnancy (Kauppila et al., 1987). Low levels of vitamin E have been reported in patients with primary biliary cirrhosis, and in children with Alagille s syndrome or biliary atresia (Knight et al., 1986 Jeffrey etal., 1987 Lemonnier etal., 1987 Babin etal., 1988 Kaplan et al., 1988 Sokol etal., 1989). Serum levels of Mn-SOD are increased in patients with all stages of primary biliary cirrhosis compared with patients with other forms of chronic liver disease, although whether this causes or results from the disease process is unclear (Ono etal., 1991). 

Initial screening tests to confirm the presence of hypercorti-solism and differentiate Cushing s syndrome from conditions with similar presentations include 24-hour urinary free cortisol determination and overnight low-dose dexam-ethasone suppression test (DST) (Table 42-9). 

Arii T, Ohyanagi M, Shibuya J, Iwasaki T 1999 Increased function of the voltage-dependent calcium channels, without increase of Ca2+ release from the sarcoplasmic reticulum in the arterioles of spontaneous hypertensive rats. Am J Hypertens 12 1236-1242 Attree O, Olivos IM, Okabe I et al 1992 The Lowe s oculocerebrorenal syndrome gene encodes a protein highly homologous to inositol polyphosphate-5-phosphatase. Nature 358 239-242 Brading AF, Turner WH 1994 The unstable bladder towards a common mechanism. Br J Urol 73 3-8... 

C3. Chard, T., Lowings, C., etal, Alphafetoprotein and chorionic gonadotropin levels in relation to Down s syndrome. Lancet 2(8405), 750 (1984). 

Children with Tourette s syndrome and ADHD refractory to other ADHD medication (n = 29) were treated openly with an average deprenyl dose of 8 mg/ day (Jankovic, 1993). The vast majority of patients (26/29) reported clinical improvement with no serious adverse outcomes. Mild side effects that did not require discontinuation of the drug were noted in six patients. Two patients had exacerbations of their tics. A later controlled trial of low-dose selegiline (10 mg/day) did not demonstrate statistically significant improvement of ADHD symptoms in children with Tourette s syndrome (Feigin et ah, 1996). 

Preliminary studies suggest that MAOIs are effective in juvenile and adult ADHD. In a controlled trial of clorygline (MAOI-A) and tranylcypromine sulfate (mixed), Zametkin et al. (1985) reported a significant reduction in ADHD symptoms with minimal adverse effects. Eeigin et al. (1996) conducted a controlled trial of 10 mg of selegiline (which at low doses is a specific MAOI-B) in children with ADHD and Tourette s syndrome. Selegiline was well tolerated and was associated... 

Psychologically Normal People Charles Bonnet s Syndrome, Lancet, 347 794-797, March 1996. (Describes the research at the Low Vision Unit of the Department of Ophthalmology, University Hospital, Nijmegen, which shows that the Bonnet visions are sometimes comical, like two miniature policemen guiding a midget villain. )... 

The activity of the enzyme in cancer tissue has been measured,11 and changes in its activity in vaginal fluid have been examined as a possible diagnostic aid in cervical cancer.29 Low levels in human tissues have been associated with a storage disorder resembling Hurler s syndrome.18,183... 

Increased biosynthesis of prostaglandins has been associated with one form of Bartter s syndrome. This is a rare disease characterized by low-to-normal blood pressure, decreased sensitivity to angiotensin, hyperreninemia, hyperaldosteronism, and... 

Liddle s syndrome is an autosomal dominant form of hypertension. It is a disorder of the renal epithelial sodium channel, which has three subunits, a, j, and y, and mutations within the first two are associated with increased sodium channel activity [7, 36]. This causes excessive sodium absorption in the distal nephron of the kidney. It gives rise to hypoglycemia, low -renin, and low aldosterone. 

Iatrogenic Cushing s syndrome after a single low dose is exceptional (120). 

---