Failure of short-term mannose therapy of patients with carbohydrate-deficient glycoprotein syndrome type 1A.

Carbohydrate-deficient glycoprotein syndrome type 1A (CDGS1A) is an inherited disorder with multisystemic abnormalities resulting from failure to generate sufficient lipid-linked oligosaccharide precursor or to transfer the sugar chain to many glycoproteins. Cultured fibroblasts from these patients have reduced incorporation of mannose into glycoproteins which can be corrected by adding D-mannose to the culture medium. Providing dietary mannose to elevate mannose concentrations in vivo therefore might remedy some of the underglycosylation in the patients. Five children with CDGS1A aged 15 months to 14 y completed a protocol of enteral supplementation with D-mannose 100 mg/kg every 3 h for 9 d. The mean S-mannose level increased from 32 microM (range 22-42 microM) to a trough value of 72 microM (range 39-103 microM). No serious side effects were observed. Surprisingly, the mean serum concentration of four glycoproteins (transferrin, alpha1-antitrypsin, antithrombin, and thyroxine-binding globulin) tended to decrease, and the mean serum concentration of carbohydrate-deficient transferrin (CDT) increased. Furthermore, the initially present abnormal isoforms of these glycoproteins and of protein C became more prominent and/or additional abnormal isoforms appeared. This short-term trial does not support a benefit of mannose to the deficient glycosylation of CDGS1A patients.

Khat-chewing during pregnancy-effect upon the off-spring and some characteristics of the chewers.

In a study of 1,141 consecutive deliveries at delivery centres in the Yemen Arab Republic, the effects of khat (catha edulis) upon the offspring have been studied. The leaves of the shrub khat contain euphorizing compounds and are chewed often, even daily, by many inhabitants. Non-users of khat (n = 427) had significantly fewer low birth-weight babies (less than 2,500 gram) compared to occasional users (n = 223) and regular users (n = 391). The khat-chewing mother was older, of greater parity and had more surviving children than the non-chewers. Significantly more khat-chewers had concomitant diseases. There was no difference in rates of stillbirth or congenital malformations.

Cerebral function of the guinea pig neonate after chronic intrauterine exposure to khat (Catha edulis Forsk.).

Cerebral function in normoxia and its reactions to standard periods of hypoxia of increasing severity were studied in 30 newborn guinea pigs less than 3 days old. Intrauterine growth retardation was induced either by uterine artery ligation at midgestation or by feeding the female in late gestation with khat leaves, an amphetamine-like stimulant chewed by men and women in several countries in eastern Africa and Arabia. After spontaneous delivery, the neonates were anesthetized and ventilated. Cardiovascular, metabolic, and neurophysiologic (somatosensory evoked potentials) parameters were monitored. Under normoxia, the khat-exposed group showed prolonged latency of the primary response of the somatosensory evoked potentials and a reduced amount of secondary components. Under hypoxia, this group also has a greater reduction of amplitude of the somatosensory evoked potentials. It is concluded that khat exposure during fetal life has an impact on the cerebral function during the neonatal period (at least up to 3 days of age) which is not solely explained by the concomitantly produced growth retardation.

Effect of khat on maternal food intake, maternal weight gain and fetal growth in the late-pregnant guinea pig.

Khat chewing is a widespread male social habit in countries around the southern shore of the Red Sea and in eastern Africa and is also practiced by women, even during pregnancy and lactation. In order to study the potentially adverse effects of khat chewing during pregnancy, guinea pigs were fed 2.2 g/kg of khat leaves daily throughout the third trimester. Control animals were given aspen leaves. Maternal daily food intake was significantly reduced during the first 10 days of feeding and maternal weight gain was slightly lower in the khat group. Khat feeding of the mother significantly reduced the mean birth weight of the offspring by 7% without any effect on litter size or length of gestational period. Since low birth weight is a well-established risk factor for both perinatal and young infant death, khat chewing during pregnancy may be one of the factors contributing to infant mortality.

Effect of khat on uteroplacental blood flow in awake, chronically catheterized, late-pregnant guinea pigs.

In order to investigate effects of khat chewing on uteroplacental blood flow, eight awake, chronically catheterized guinea pigs were fed 2.2 g khat leaves/kg in late pregnancy and regional blood flows were measured with the microsphere technique. Seven animals fed with aspen leaves in the same amounts served as controls. The mean concentration of (+)-norpseudoephedrine in urine 3 h after the end of the feeding was 4.6 micrograms/ml in the khat-fed group with no detectable amounts in the controls. Placental blood flow was reduced by 10% 75 min and by 24% 180 min after khat feeding. Since the khat dose used gave urinary concentrations of (+)-norpseudoephedrine of the same magnitude as those reported in khat chewing women, khat chewing in pregnancy may reduce placental blood flow and impair fetal growth.

Use of khat in lactating women: a pilot study on breast-milk secretion.

Nor-pseudoephedrine, one of the active ingredients of khat (Catha edulis), was found to be excreted in breast-milk in several lactating women who were chewing the leaves of the shrub according to the local customs. The compound could be traced in the urine of one breast-fed infant. It is concluded that the use of khat during lactation should be discouraged until further research has clearly elucidated the potential health hazards.

Effect of the khat alkaloid (+)norpseudoephedrine on uteroplacental blood flow in the guinea pig.

In order to investigate effects of khat chewing on uteroplacental blood flow (+)norpseudoephedrine (NPE) infusions were given to 11 anesthetized guinea pigs in late pregnancy (62-66 days) after unilateral uterine artery ligation at days 30-32. Regional blood flows were determined with radioactive microspheres. Mean arterial blood pressure increased with 25% and heart rate with 9% during NPE infusion. Myoendometrial blood flow was reduced by 31%. Placental vascular resistance (PVR) increased by 56% in the control horn (17 fetuses) and by 82% in the ligated horn (17 fetuses). This vasoconstriction was counteracted by the systemic vasopressor response since placental blood flow remained unchanged. When considering only the 13 growth-retarded fetuses, however, PVR increased by 98% and a 19% reduction of placental blood flow could be demonstrated. These results suggest that the placenta of the growth-retarded fetus may be more sensitive to adrenergic stimulation than the normal placenta. Furthermore, since one of the active constituents of khat, (+)norpseudoephedrine, causes vasoconstriction in the uteroplacental vascular bed it is possible that khat chewing could reduce placental blood flow and, as a consequence, impair fetal growth.

The influence of khat-chewing on birth-weight in full-term infants.

The leaves of the shrub Catha edulis (khat) are widely chewed as part of social life in several countries around the Red Sea and in East Africa. The leaves possess stimulant properties and are also used by pregnant women. The effect of khat on birth-weight has been studied, It was found that healthy full-term, singletons, born after uneventful pregnancies and deliveries, had a significantly lower average birth-weight when the mothers were khat-chewers, either habitually or occasionally (P less than 0.001). Khat-chewing appears to be one of several maternal practices adverse to the fetus.