The distinction between arylsulphatases in chorionic villi

The relatively high activity of arylsulphatase C (ASC) in the placenta is a potential risk for the misdiagnosis of arylsulphatase A (ASA) or arylsulphatase B (ASB) deficiency in chorionic villus sampling when assayed by synthetic substrates. A clear distinction between these enzymes can be achieved in either the direct villi or the cultured villi cells. Interestingly, the activity of ASC differed significantly in cultured villi cells when prepared by two different methods, namely, minced villi versus treatment with trypsin and collagenase, while ASA and ASB were not affected by these treatments. Whether ASC was directly affected by one of these treatments or whether a selection of cells with different ASC levels was achieved is not yet clear, but this phenomenon clearly indicates the importance of precise definition of CVS preparations to correlate with the enzyme activity data.

The usefulness of open-lung biopsy in the pediatric bone marrow transplant population

From October 1976 to October 1986, 126 children had bone marrow transplants at the Children's Hospital of Philadelphia. The indications were acute lymphocytic leukemia (ALL) (30), nonlymphocytic leukemia (24), aplastic anemia (15), solid tumors (47), and miscellaneous conditions (10). Of these, 21 (17%) underwent 22 open-lung biopsies. Fourteen of these patients showed no causative microorganism. When a cause was found it was viral (usually cytomegalovirus [CMV]) in three, fungal in one, Pneumocystis carinii alone in two, both viral and pneumocystis in one, and a combination of viral, bacterial, and pneumocystis in one. Thirteen patients died due to continued deterioration after the biopsy. In only two patients was there a significant change in antimicrobial therapy as a result of the biopsy. Both had Pneumocystis (one in combination with virus and bacteria). One patient with chronic infiltrates showed a lymphocytic interstitial pneumonia, which responded well to steroids. Open-lung biopsy is currently of limited value in this patient population. Survival is dismal unless the patient has Pneumocystis. We believe that prospective studies should be set up to compare open-lung biopsy with empiric antimicrobial therapy. A major emphasis must be on prevention.

Selection in favor of lysosomal storage disorders?

Four examples of Israeli communities or large families in which high consanguinity is common are presented, with two different lysosomal storage disorders within each community. In each of the four cases the stored substances share common chemical structure, despite the different lysosomal hydrolases involved in each disease. A similar phenomenon is known among the Ashkenazi Jews, in whom four of the most frequent hereditary disorders are lysosomal storage disorders, which are characterized by storage of sphingolipid derivatives. Similar findings are reported in the literature in other communities. We suggest that this phenomenon indicates a selection in favor of lysosomal storage disorders of similar nature in certain populations. The selection forces leading to this phenomenon have not been identified yet, and it has not yet been determined whether these forces are the same in the different communities presented here.

Internalization of exogenous gangliosides in cultured skin fibroblasts for the diagnosis of mucolipidosis IV

The internalization of exogenous mixed brain gangliosides in ML IV cultured skin fibroblasts indicated an impairment of ganglioside catabolism in these cells. Incubation of ML IV, normal and various other lysosomal storage disorders cell lines for five days with exogenous tritium labelled GM3, GD1a or GT1 gangliosides allowed accurate quantitation of the retained gangliosides. This in vitro approach provides a reliable method for the diagnosis of ML IV.

Hunter syndrome among Ashkenazi Jews in Israel; evidence for prenatal selection favoring the Hunter allele

Analysis of Ashkenazi families with Hunter patients in Israel demonstrated the complete absence of new mutations among the probands' mothers. Furthermore, in these families a significant deviation of the segregation ratio between the Hunter gene and the normal allele was demonstrated among offspring of heterozygous mothers or siblings of affected children. This may be due to pre- or postzygotic prenatal selection, favoring the X chromosome carrying the Hunter gene among Ashkenazi Jews.

Ganglioside sialidase distribution in mucolipidosis type IV cultured fibroblasts

The subcellular distribution of ganglioside sialidase in Mucolipidosis IV (ML IV) cells was characterized by a series of Percoll gradients. Similar to normal cells, the enzyme cosedimented with plasma membrane markers, although this activity was reduced and exhibited decreased solubility in ML IV cells. Only trace amounts of ganglioside sialidase (less than 5%) was found in the lysosomes of normal cells. This activity was apparently reduced in ML IV cells but its minute activity in controls excluded further characterization of these differences. Plasma membranes on 6.7 and 5.6% Percoll gradients were biomodally distributed. Ganglioside sialidase in normal cells was found to be in both the heavier and the lighter membrane fractions, whereas the enzyme in ML IV cells was associated mainly with the denser membrane fraction. These data indicate that the enzyme in ML IV cells is characteristically different from normal in that it exhibits reduced activity and solubility and a different plasma membrane distribution.

Krabbe disease: increased incidence in a highly inbred community

Krabbe disease (globoid cell leukodystrophy) was found with very high incidence (6/1,000 live births) in a large Druze kindred in Israel. The clinical data on 12 of the affected children demonstrated clinical variability even though these children are homozygous for the same mutation by descent from a common ancestor.

Prenatal diagnosis of Krabbe disease using a fluorescent derivative of galactosylceramide

A fluorescent substrate 12-(N-methyl-N(7-nitro-2-oxa-1,3-diazol-4-yl) aminododecanoyl sphingosyl beta-D-galactoside ('NBD galactocerebroside') was synthesized and used for the detection of galactocerebrosidase activity. The enzyme determinations using this substrate were found to be extremely sensitive yielding unambiguous results. This substrate was used for the prenatal diagnosis of a fetus affected with Krabbe disease; the diagnosis was later confirmed in the aborted fetus.

Infantile lethal neuraminidase deficiency (sialidosis)

An infant suffering from failure to thrive, hepatosplenomegaly, developmental retardation and early infantile death is described. The proposita demonstrated a type 2 early infantile sialidosis with onset at birth, and death at 4 months. A culture of the proband's fibroblasts showed neuraminidase deficiency, and low activity of the enzyme was found in the lymphocytes of both parents. A previous female child, born prematurely, died 6 h after birth and had hepatosplenomegaly and foam cells in the placenta. There is strong evidence that the inheritance of the disease is autosomal recessive.

Cellular localization of neuraminidases in cultured human fibroblasts

The cellular localization of glycoprotein and ganglioside sialidases in normal and I-cell-disease cultured fibroblasts has been investigated. Cellular organelles have been separated on a colloidal silica gradient. The subcellular distribution of these enzymes indicated that the glycoprotein sialidase is mainly a lysosomal hydrolase, whereas the ganglioside sialidase is primarily located in the plasma membranes. The latter isoenzymes is tightly bound to these membranes and thus could not be extracted by homogenization in the presence of Triton X-100. The interpretation of this finding and its relation to the pathochemistry of sialidase-deficient disorders is discussed.

Biochemical investigations of cultured amniotic fluid cells in mucolipidosis type IV

Biochemical abnormalities similar to those observed in cultured fibroblasts of patients with mucolipidosis type IV were demonstrated in cultured amniotic fluid cells of two fetuses affected with mucolipidosis IV. Increased gangliosides and acid mucopolysaccharides were observed in the affected cultures when compared to two normal controls. Both GM3 (monosialo) and GD3 (disialo) gangliosides accumulated in the affected cells: the latter showing a three-fold and the former a two-fold increase over controls. The major mucopolysaccharide components were dermatan sulfate and heparan sulfate, both increased approximately four-fold. A partial, but significant deficiency of soluble ganglioside sialidase was observed in the two affected cultures, while this activity was normal in a culture of a non-affected fetus of the same mother in a third pregnancy. Non-soluble membrane-bound and neuraminlactose sialidase was not affected.

Nortriptyline hydrochloride in urology

Forty female patients suffering for long periods from frequency, urgency, and dysuria without any definite organic cause received nortriptyline chloride for three weeks. In 75 percent there was either considerable improvement or total disappearance of urinary complaints. At the same time the in vitro effects of the drug were tested using the isometric muscle contraction technique. Nortriptyline was found to have anticholinergic properties. The importance of this effect in the clinical study and the possible mode of action of the drug are discussed.

Adrenergic and cholinergic receptors in the human prostate, prostatic capsule and bladder neck

The adrenergic and cholinergic receptors of the human prostatic capsule, prostatic "adenoma", and bladder neck, were investigated by the in-vitro isometric technique. The prostatic capsule was found to be very rich in both alpha-adrenergic receptors and cholinergic receptors. The prostatic adenoma was moderately rich in alpha-adrenergic receptors, but cholinergic receptors were absent. Beta-adrenergic receptors were absent in the prostatic adenoma, and there was an equivocal response in less than half the specimens of the prostatic capsule. An attempt was made to distinguish between the trigonal component at the posterior bladder neck, and the true bladder neck muscle both posteriorly and antero-laterally. The results indicat that the "posterior bladder neck" seen at operation is predominantly trigonal muscle, and is poor in cholinergic receptors. The adrenergic response is variable in the true bladder neck muscle, but is present and strong in the trigonal muscle. This response is characteristically gradual in its development. In view of the findings in this investigation, it is suggested that certain instances of acute retention of urine in prostatic patients are due to over-stimulation of the alpha-adrenergic receptors, particularly those in the prostatic capsule. Similarly, the accepted clinical contraindication to the use of cholinergic drugs for retention in the prostatic patient is supported by the distribution of the cholinergic receptors in the tissues examined.