Hereditary endotheliopathy with retinopathy, nephropathy, and stroke (HERNS)

We describe a Chinese American family with a hereditary syndrome consisting of retinopathy, nephropathy, and stroke, affecting 11 members spanning three generations. Ophthalmologic evaluations revealed macular edema with capillary dropout and perifoveal microangiopathic telangiectases. Several members had renal abnormalities with proteinuria and hematuria. Initial manifestations were visual impairment and renal dysfunction; neurologic deficits occurred in the third or fourth decade of life. Symptoms included migraine-like headache, psychiatric disturbance, dysarthria, hemiparesis, and apraxia. Neuroimaging consistently demonstrated contrast-enhancing subcortical lesions with surrounding edema. Ultrastructural studies showed distinctive multilaminated vascular basement membranes in the brain and in other tissues, including the kidney, stomach, appendix, omentum, and skin. Genetic analysis ruled out linkage to the CADASIL locus on chromosome 19. Distinct from CADASIL, hereditary endotheliopathy with retinopathy, nephropathy, and stroke (HERNS) is an autosomal dominant multi-infarct syndrome with systemic involvement.

Dietary calcium attenuates platelet aggregation and intracellular Ca2+ mobilization in spontaneously hypertensive rats

Spontaneously hypertensive rats (SHR) are known to be blood pressure sensitive to dietary calcium. The effects of dietary calcium on platelet aggregation and intracellular Ca2+ mobilization were assessed by turbidimetric methods and fura-2 methods, respectively, in washed platelets of SHR. Ca2+ ATPase activity was examined in aortic membrane fractions. Six weeks of dietary calcium supplementation attenuated the increase of systolic blood pressure (SBP 199 +/- 16 v 170 +/- 9 mm Hg, P < .001) and thrombin-induced platelet aggregation (84.5 +/- 3.7 v 73.7 +/- 7.4%, P < .004) at 9 weeks of age. The ionomycin-induced intracellular calcium ([Ca2+]i) peak in the absence of external Ca2+, which reflects [Ca2+]i storage size, and thrombin-evoked [Ca2+]i release from [Ca2+]i storage were decreased by 2.0% Ca diet (472 +/- 55 v 370 +/- 23 nmol/L, P < .001, 339 +/- 29 v 278 +/- 33 nmol/L, P < .002). In addition, SBP was positively correlated with platelet aggregation (r = 0.703, P = .0088), thrombin-evoked [Ca2+]i (r = 0.739, P = .0044), and ionomycin-induced [Ca2+]i (r = 0.591, P = .0415), respectively. However, there was no significant effect of dietary calcium on Ca2+-ATPase activity in aortic membranes. These results suggest that dietary calcium supplementation had a beneficial effect on platelets of SHR by attenuating [Ca2+]i mobilization from [Ca2+]i storage. The hypotensive effect of dietary calcium might be associated with attenuated [Ca2+]i mobilization in SHR.

Familial episodic ataxia: clinical heterogeneity in four families linked to chromosome 19p

We describe the clinical and oculographic findings in 4 families with episodic ataxia and interictal nystagmus (EA-2) linked to chromosome 19p. Episodes varied from pure ataxia to combinations of symptoms suggesting involvement of the cerebellum, brainstem, and cortex. Some affected individuals exhibited a progressive ataxia syndrome phenotypically indistinguishable from the dominantly inherited spinocerebellar ataxia (SCA) syndromes. About one-half of the affected individuals had migraine headaches and several had episodes typical of basilar migraine. Oculographic findings were localizing to the vestibulocerebellum and posterior vermis. Additional genetic and environmental factors must account for the marked clinical heterogeneity in these families with an abnormal gene on chromosome 19p.

Familial migraine with vertigo and essential tremor

We report a family with dominantly inherited migraine headaches, episodic vertigo, and essential tremor. All symptoms improved with the use of acetazolamide. Linkage analysis ruled out linkage to markers on chromosome 19p, known to be linked to the genetic defect in families with the clinically similar syndromes of hemiplegic migraine and periodic ataxia. This genetic heterogeneity of migraine syndromes could result from defects in a family of genes coding proteins with similar properties.

Mechanisms of calcium's effects on blood pressure

Manipulations of dietary calcium have been repeatedly shown to alter blood pressure in animal models of human essential hypertension. Supplemental dietary calcium lowers blood pressure, whereas restricted calcium diets tend to elevate blood pressure. The mechanisms responsible have not been identified, but numerous possibilities have been proposed. Many of the proposals have attempted to relate dietary calcium to calcium metabolism in vascular smooth muscle and altered vascular tone. Other proposals have focused on neural, hormonal, and renal effects of dietary calcium. In this article, mechanisms through which elevations in extracellular calcium levels might influence intracellular calcium levels are explored. Also examined are the potential roles of calcium regulating hormones, sympathetic nervous system, and electrolyte interactions in modifying blood pressure.

White matter lesions and disequilibrium in older people. I. Case-control comparison

OBJECTIVE

To investigate the relationship between subcortical white matter lesions identified on magnetic resonance imaging and gait and balance problems in older people.

DESIGN

Magnetic resonance imaging scans of the brain in 27 community-dwelling older patients (> 75 years of age) who had subjective and objective abnormalities of gait and balance of unknown cause were compared with those of 27 age- and sex-matched control subjects. The T2-weighted intense lesions of the subcortical white matter were graded on a scale of 0 to 2.

SETTING

Outpatient clinic.

RESULTS

The patient had significantly (P < .01, chi 2) more severe subcortical white matter hyperintensities on magnetic resonance imaging than did the control group. Patients fell more frequently than did the control subjects and had slower motor responses and prolonged reaction times compared with the control subjects.

CONCLUSIONS

Subcortical white matter lesions identified on magnetic resonance imaging are associated with gait and balance dysfunction in ambulatory older people. These lesions probably interfere with central processing of sensorimotor signals leading to impaired postural responses.

The linear vestibulo-ocular reflex in normal subjects and patients with vestibular and cerebellar lesions

We measured the horizontal linear vestibulo-ocular reflex (LVOR) in normal human subjects and patients with abnormal angular vestibulo-ocular reflexes (AVOR) and abnormal smooth pursuit. Eye movements were induced by sinusoidal linear acceleration along the interaural axis (0.8 Hz, 0.5 g peak acceleration) on a parallel swing. Horizontal movement of each eye was recorded with an infrared limbus tracking device. Normal subjects increased LVOR sensitivity as real or imagined targets moved closer. Perceived target distance was more important than the vergence angle since changing the vergence angle alone with prisms resulted in only a slight change in LVOR sensitivity. Subjects suppressed the LVOR with real or imagined head-fixed targets. Patients with decreased horizontal AVOR responses had decreased horizontal LVOR responses with imagined earth-fixed targets in the dark. They were able to generate normal velocity LVOR responses with real earth-fixed targets. Patients with increased AVOR responses and poor smooth pursuit due to cerebellar atrophy had low LVOR responses that were minimally affected by real or imagined earth-fixed or head-fixed targets. We conclude that the smooth pursuit system and the cerebellum are critical for generating the eye movements required as subjects fixate a near target during translational head movements.

Rearranged taxoids from Taxus yunnanensis

Two rearranged 2(3-->20)abeotaxanes were isolated from the leaves and stems of Taxus yunnanensis, and designated as taxin B and 2-deacetyltaxin B. The structure of taxin B with a unique 6/10/6 skeleton was deduced on the basis of 1H-NMR, 13C-NMR, 1H-1H COSY, DEPT, NOE, and mass spectra and confirmed by X-ray crystallographic analysis. The structure of 2-deacetyltaxin B is elucidated by analog.

Persistent direction-changing positional nystagmus: another variant of benign positional nystagmus?

Positional nystagmus that does not fatigue, persists as long as the position is held, and changes direction in different head positions has typically been attributed to central vestibular lesions. We recently studied three patients who presented with positional nystagmus having these features but almost certainly of benign peripheral origin. All three had an initial history typical of benign positional vertigo and, in two, the persistent direction-changing positional nystagmus occurred after the patient underwent a maneuver to remove debris from the posterior semicircular canal. The positional nystagmus profile and clinical course are consistent with the debris leaving the posterior semicircular canal and becoming attached to the cupula of the horizontal semicircular canal.

Three-dimensional characteristics of rhesus monkey vestibular nystagmus after velocity steps

In rhesus monkeys we have investigated 3-dimensional orientations of angular eye velocity vectors during vestibular step responses about an earth-vertical axis. Monkey body position with respect to the rotation axis was systematically changed between upright, 90 degrees ear-down, and supine positions to induce oblique eye movements with horizontal, vertical, and torsional components, respectively. Angular eye velocity axes deviated from stimulus axes due to two types of anisotropies in the vestibulo-ocular reflex, that is, gain anisotropy and velocity-storage anisotropy. Deviations of eye velocity vectors from stimulation axes at peak slow-phase velocity could well be predicted by vectorial summation of gains obtained for the cardinal directions (horizontal, vertical, and torsional). During nystagmus decay, time constants after oblique velocity steps showed a tendency to be similar in participating components. However, this adjustment of time constants was incomplete for horizontal-torsional and horizontal-vertical-down vestibular responses, leading to an orientation change of eye rotation axes during slow-phase velocity decay with a bias toward the horizontal eye movement component.

[Effect of ma-xin-shi-gan tang on the immune function in children with acute lower respiratory tract infection]

This paper reported the effect of Ma-Xin-Shi-Gan tang (Decoction of Herba Ephedrae, Semen Armeniacae Amarum, Radix Glycyrrhizae and Gypsum Fibrosum) on the immune function of the children with acute lower respiratory tract infection (ALRTI). 64 cases of ALRTI children were chosen for clinical observation. Laboratory researches including 7 immune indexes: blood OKT3+ cell, OKT4+ cell, OKT8+ cell and OKT4+/OKT8+ cell ratio, serum IgG, IgA, IgM. Some tests in experimental mice were also made. The results showed: (1) Before treatment, the blood OKT3+ cell, OKT4+ cell and OKT4+/OKT8+ cell ratio of the ALRTI children were lower, OKT8+ cell was higher than that of the normal group, which indicated lowered function of cell mediated immunity (CMI) in ALRTI children. Furthermore, IgM content in serum of the ALRTI children was significantly higher than that of the normal group, which indicated a hyperhumoral immunity (HI). (2) Blood OKT4+ cell and OKT4+/OKT8+ cell ratio in children after treatment with the Decoction were higher than those before treatment, which suggested the Decoction can regulate the cell ratio of OKT4+ and OKT8+, and relieve the functional inhibition of CMI in ALRTI children, while comparing with the western medicine (WM) group, the blood OKT3+ cell, OKT4+ cell and serum IgG content in the Decoction group after treatment were higher. In the WM group, the serum IgG and IgA contents were lower than those of the normal group, which indicated inhibited function of HI after treatment. (3) In experimental mice, the Decoction can increase the phagocytic index of the macrophage, the spleen index and the level of serum hemolysin. It can also enhance the skin delayed allergic reaction of the mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucuronidation of codeine and morphine in human liver and kidney microsomes: effect of inhibitors

Glucuronidation of codeine was detected and compared with that of morphine in microsomes from human livers and kidneys. Vmax values for codeine-6-glucuronide (C6G) were 0.54 +/- 0.24 and 0.74 +/- 0.35 nmol/mg/min. in the livers and 0.10 and 0.13 nmol/mg/min. in the kidney, respectively, when codeine and UDP-glucuronic acid (UDPGA) were incubated with microsomal preparation. The corresponding Km values were 2.21 +/- 0.68 and 1.41 +/- 0.36 mM in the livers and 6.69 and 4.12 mM in the kidney. The average codeine glucuronyltransferase (GT) activity was 14-fold lower in the six kidneys than in the 11 livers. Higher GT activities were observed in liver microsomes from patients who had been exposed to enzyme inducers. Rates of glucuronide formation from morphine correlated significantly with those from codeine in both human liver and kidney microsomes. Morphine, amitriptyline, diazepam, probenecid and chloramphenicol inhibited codeine glucuronidation with Ki values of 3.6, 0.13, 0.18, 1.7 and 0.27 mM, respectively.