Ifosfamide-induced subclinical nephrotoxicity and its potentiation by cisplatinum

Renal function was assessed in 72 children and adolescents 3.5 to 123 months after completion of chemotherapy employing ifosfamide (n = 39) or ifosfamide plus cisplatinum (n = 33). No patient had preexisting renal parenchymal disease. Whereas reduction in glomerular filtration rate was present in six of 69 patients (8.7%), impairment of tubular transport for phosphate, glucose, and amino acids was more frequent: 32.8% of the patients showed reduction in phosphate reabsorption, and glucose and amino acid reabsorption was lowered in 16.4% and 55.0%, respectively. Elevated sodium excretion was found only occasionally, and there was no evidence of renal tubular acidosis. Proximal tubular damage is related to ifosfamide chemotherapy, but correlation between ifosfamide dose and phosphate reabsorption was not linear. The most severe depletion of phosphate reabsorption was seen in patients treated with both ifosfamide and cisplatinum. On reexamination of phosphate reabsorption after a median interval of 8 months, the majority of patients with initially reduced values showed further deterioration of this function. © 1994 Wiley-Liss, Inc.     

Clinical features of the spinal form of multiple sclerosis

Out of a data pool of 1271 patients with Multiple Sclerosis (MS) a total of 109 cases are selected having a sole spinal symptomatology throughout the course of the disease. This group differs in three particular features from the non-spinal forms of MS: In this group there is a higher percentage of females, the age at onset of the disease is higher, and the course of the disease is more often chronic progressive from the beginning. After the mean duration of 11 years, the spinal and the non-spinal cases show the same grade of disability. The ability to work is slightly better for spinal cases; office workers are able to keep their jobs longer after the onset to the disease than patients with any other occupation. The spinal form of MS is discussed in respect to its relationship to the classical form of MS and as a differential diagnosis to other spinal processes.     

Renal failure and hypertension in Alagille syndrome with a novel JAG1 mutation

Renal failure and hypertension in Alagille syndrome with a novel JAG1 mutation: Alagille syndrome is an autosomal dominant disorder involving liver, heart, eyes, face, skeleton, and other organs. Various renal abnormalities have also been associated with Alagille syndrome, whereas renal vascular hypertension combined with renal insufficiency has been reported in several cases. We describe a patient with a novel frameshift mutation (c.1880_1881insA) in the JAG1 gene who presented with chronic renal failure and hypertension but without evidence of renal vascular or aortic stenosis. The patient's chronic renal failure had persisted for several years. His high blood pressure seemed to be due to renal parenchymal changes and was treated with ACE-inhibitors without worsening his renal function. This novel JAG1 mutation revealed great variability of the phenotype. The patient's daughter suffered from severe paucity of intrahepatic bile ducts and received a liver transplant at the age of two years. These findings are discussed including a review of the literature.     

Rapid genotyping of blood group antigens by multiplex polymerase chain reaction and DNA microarray hybridization

BACKGROUND: In the Netherlands, 500,000 blood donors are active. Blood of all donors is currently typed serologically for ABO, the Rh phenotype, and K. Only a subset of donors is typed twice for a larger set of red cell (RBC) and/or platelet (PLT) antigens. To increase the direct availability of typed RBCs and PLTs, a high-throughput technique is being developed to genotype the whole donor cohort for all clinically relevant RBC and PLT antigens. STUDY DESIGN AND METHODS: A multiplex polymerase chain reaction was developed to both amplify and fluorescently label 19 gene fragments of RBC and PLT antigens in one reaction. To test the setup of the genotyping method by microarray, a pilot study with human PLT antigen (HPA)-typed donor samples was performed. On each slide, 12 arrays are present containing 20 probes per PLT antigen system (28 for HPA-3). The allele-specific oligohybridization method was used to discriminate between two different alleles. RESULTS: Two blinded panels encompassing 94 donors were genotyped for HPA-1 through -5 and -15; no discrepancies were found compared to their serologic typing (HPA-1, -2, -3, -4, and -5) and genotyping (HPA-15; TaqMan, Applied Biosystems). CONCLUSION: This study shows that the HPA microarray provides a reliable and fast genotyping procedure. With further development an automated throughput for complete typing of large donor cohorts can be obtained.     

Age at onset, initial symptomatology and the course of multiple sclerosis

Analysis of the initial symptomatology, age at onset and course as factors influencing the prognosis of multiple sclerosis (MS) revealed that the rate of deterioration in a sample of 1,571 patients - registered during a neurological examination in a standardized way - was slower for patients with optic neuritis as the initial sign, for patients with an age at onset of under 39 years and for patients with a remissive course of disease.
The progression index, obtained by dividing the present disability by the duration of the disease was used as a measure for the rate of progression.
The course of the disease was responsible for 13% and age at onset for 1.6% of the total variation in the progression index.
Endogenous or exogenous factors may modify the appearance and dynamics of MS which might be a syndrome rather than a disease entity.     

TRPV1 regulators mediate gentamicin penetration of cultured kidney cells

Transient receptor potential (TRP) receptors are, typically, calcium-permeant cation channels that transduce environmental stimuli. Both kidney epithelial and inner ear sensory cells express TRPV1, are mechanosensors and accumulate the aminoglycoside antibiotic gentamicin. Recently, we showed that Texas Red-conjugated gentamicin (GTTR) enters kidney cells via an endosome-independent pathway. Here, we used GTTR to investigate this non-endocytotic mechanism of gentamicin uptake. In serum-free buffers, GTTR penetrated MDCK cells within 30 s and uptake was modulated by extracellular, multivalent cations (Ca2+, La3+, Gd3+) or protons. We verified the La3+ modulation of GTTR uptake using immunocytochemical detection of unconjugated gentamicin. Membrane depolarization, induced by high extracellular K+ or valinomycin, also reduced GTTR uptake, suggesting electrophoretic permeation through ion channels. GTTR uptake was enhanced by the TRPV1 agonists, resiniferatoxin and anandamide, in Ca2+-free media. Competitive antagonists of the TRPV1 cation current, iodo-resiniferatoxin and SB366791, also enhanced GTTR uptake independently of Ca2+, reinforcing these antagonists' potential as latent agonists in specific situations. Ruthenium Red blocked GTTR uptake in the presence or absence of these TRPV1-agonists and antagonists. In addition, GTTR uptake was blocked by RTX in the presence of more physiological levels (2 mM) of Ca2+. Thus gentamicin enters cells via cation channels, and gentamicin uptake can be modulated by regulators of the TRPV1 channel.     

Macrocephalic mental retardation associated with a novel C-terminal <Emphasis Type="Italic"> MECP2</Emphasis> frameshift deletion

We report a novel C-terminal MECP2 frameshift deletion (1135_1142delCCCGTG CC) in a 19-year-old woman with mental retardation and epilepsy. Preservation of language capabilities, purposeful hand use and sufficient locomotion implied an atypical variant of Rett syndrome (OMIM 312750). Occipito-frontal head circumference was large at birth (36 cm; SDS 1.7) and increased until adulthood (58.5 cm; SDS 2.3). Conclusion: Our observation indicates that head size and head growth are of limited reliability in the diagnosis of MECP2-associated phenotypes.     

Relationship between allopregnanolone and negative mood in postmenopausal women taking sequential hormone replacement therapy with vaginal progesterone

OBJECTIVE: To compare severity of negative mood and physical symptoms between women with different progesterone, allopregnanolone, and pregnanolone plasma concentrations during sequential Hormone Replacement Therapy (HRT) with vaginal progesterone suppositories. DESIGN: A randomized, placebo-controlled, double-blind, crossover study. METHOD: Postmenopausal women (n=36) with climacteric symptoms were treated with 2mg estradiol daily during three 28-day cycles. Vaginal progesterone suppositories with 400, 800 mg/day or placebo were added sequentially for 14 days per cycle. Daily symptom ratings using a validated rating scale were kept. Blood samples for progesterone, allopregnanolone, and pregnanolone radioimmunoassays were collected during each treatment cycle. RESULTS: Women were divided into three groups (low, medium, and high) based on plasma allopregnanolone concentration during progesterone treatment. The concentration of allopregnanolone in the medium group corresponds to the concentration seen during the mid luteal phase of the menstrual cycle. Within women with medium allopregnanolone concentration significantly more negative mood and physical symptoms were rated during progesterone treatment compared to treatment with unopposed estrogen or placebo. Between women significantly more negative mood symptoms were seen during progesterone treatment cycles with medium allopregnanolone concentration compared to cycles with low concentration. Plasma progesterone, allopregnanolone, and pregnanolone concentrations increased with increasing progesterone dose. Progesterone and allopregnanolone plasma concentrations increased 2h after vaginal administration of progesterone at 400 and 800 mg/day. CONCLUSION: Vaginal progesterone in sequential HRT causes negative mood, most likely mediated via allopregnanolone.