Diminished concentrations of insulin-like growth factor I in cystic fibrosis

Cystic fibrosis is frequently accompanied by a catabolic condition with low body mass index caused by a number of disease complications. Insulin-like growth factor-I (IGF-I) is an anabolic hormone and an important marker of nutritional status, liver function, and linear growth. Available data on IGF-I in cystic fibrosis are sparse and conflicting. From 1990-3, 235 of our 240 patients (114 males, 121 females, median age 16.2 years, ranged 0.1-44.0 years) had IGF-I measured once by radioimmunoassay. IGF-I was significantly reduced compared with a healthy Scandinavian control population: mean (-2 SD to +2 SD) IGF-I SD score was -0.97 (-3.7 to 1.7) in males and -0.67 (-3.2 to 1.9) in females. Height SD score was -0.95 (-3.3 to 1.4) in males and -0.81 (-3.2 to 1.6) in females. In patients who were still in the growth period a significant correlation of IGF-I SD score to height SD score (r = 0.28, p < 0.001) was found. The low IGF-I concentrations may reflect the catabolic state of many patients with cystic fibrosis and play a part in their abnormal growth pattern.     

Retinal hemangioblastoma in von Hippel-Lindau disease: a clinical and molecular study

PURPOSE: To assess the natural history of retinal manifestations in von Hippel-Lindau (VHL) disease and to study the genotype-phenotype correlation. METHODS: Data concerning 103 patients with VHL retinal manifestations and 108 patients without VHL retinal manifestations were extracted from the French VHL database. A retrospective study was performed by questionnaire. Patients were classified into three visual morbidity groups. Molecular analysis of the VHL gene was performed in 196 patients. RESULTS: The mean age of ocular manifestations detection was 24.8 years. In half of the cases, the ocular manifestations revealed the disease. Half of the cases had bilateral involvement. Visual morbidity was significantly associated with the retinal hemangioblastoma count but not with other ocular or general characteristics. One third of the patients were classified in the worst visual morbidity group at the end of follow-up. Mutations were detected in 81% of patients with retinal hemangioblastomas and in 71% of patients without retinal involvement. Using a Poisson model and a marginal approach, the number of hemangioblastomas, age-adjusted, was 2.1 times higher in patients who had a substitution than in patients with a truncation (95% CI, 1.05-4.44; P < 0.05). CONCLUSIONS: Visual loss remains one of the major complications of VHL disease, confirming the importance of early ophthalmologic screening. Visual morbidity was not related to the type of extraocular manifestation but appeared to be related to the type of germline mutation. However, only further genetic and clinical studies in a larger series of patients will clearly determine the genotype-phenotype relationship.     

Polymorphism of roxifiban

Roxifiban was found to exist in two polymorphic forms. The polymorphs were detected by X-ray powder diffraction and solid-state carbon nuclear magnetic resonance. A slight difference between the two polymorphs was also detected by isothermal microcalorimetry. However, no differences were observed by differential scanning calorimetry, infrared, or Raman spectroscopy. Solubility studies as a function of temperature in a discriminating solvent system permitted characterization of the thermodynamics of the polymorphs. The enthalpy of solution at 25 degrees C was 8.1 kcal/mol and 8.9 kcal/mol for Form I and Form II, respectively, and the thermodynamic transition point was 132 degrees C. The data confirm that the polymorphs are enantiotropic. Form II is the thermodynamically stable crystal form over the practical range of drug substance storage and handling and dosage form processing and storage. However, Form I has been kinetically stable after storage for more than 36 months at 25 degrees C/60% relative humidity with no conversion to Form II occurring.     

Respondent-Driven Sampling in a Study of Drug Users in New York City: Notes from the Field

Beth Israel Medical Center (BIMC), in collaboration with the Centers for Disease Control (CDC) and the New York State Department of Health (NYSDOH), used respondent-driven sampling (RDS) in a study of HIV seroprevalence among drug users in New York City in 2004. We report here on operational issues with RDS including recruitment, coupon distribution, storefront operations, police and community relations, and the overall lessons we learned. Project staff recruited eight seeds from a syringe exchange in Lower Manhattan to serve as the initial study participants. Upon completion of the interview that lasted approximately 1 h and a blood draw, each seed was given three coupons to recruit three drug users into the study. Each of the subsequent eligible participants was also given three coupons to recruit three of their drug-using acquaintances. Eligible participants had to have: injected, smoked or snorted an illicit drug in the last 6 months (other than marijuana), aged 18 or older, adequate English language knowledge to permit informed consent and complete questionnaire. From April to July 2004, 618 drug users were interviewed, including 263 (43%) current injectors, 119 (19%) former injectors, and 236 (38%) never injectors. Four hundred sixty nine (76%) participants were men, 147 (24%) were women, and two (<1%) were transgender. By race/ethnicity, 285 (46%) were black, 218 (35%) Hispanic, 88 (14%) white, 23 (4%) mixed/not specified, and four (<1%) native American. Interviews were initially done on a drop-in basis but this system changed to appointments 1 month into the study due to the large volume of subjects coming in for interviews. Data collection was originally proposed to last for 1 year with a target recruitment of 500 drug users. Utilizing RDS, we were able to recruit and interview 118 more drug users than originally proposed in one quarter of the time. RDS was efficient with respect to time and economics (we did not have to hire an outreach worker) and effective in recruiting a diverse sample of drug users.     

Activation of the calcium receptor by a calcimimetic compound halts the progression of secondary hyperparathyroidism in uremic rats

The secondary hyperparathyroidism that develops in rats with chronic renal insufficiency (CRI) can be totally prevented by activation of the parathyroid Ca(2+) receptor with a calcimimetic compound, when treatment is initiated before parathyroid cell hyperplasia and increased circulating parathyroid hormone levels develop. In clinical practice, however, secondary hyperparathyroidism is usually manifest by the time CRI is diagnosed. This study examined the effects of daily oral gavage or continuous subcutaneous infusion for 8 wk of the calcimimetic NPS R-568 on the progression of established mild or moderate-to-severe secondary hyperparathyroidism in rats with CRI induced by 5/6 nephrectomy. Both oral and infused NPS R-568 completely prevented further hyperplasia but did not reduce total parathyroid cell number below that present at the initiation of treatment. This prevention of cellular proliferation occurred despite increases in plasma phosphate and decreases in Ca(2+) and 1, 25-dihydroxyvitamin D levels, and supports the view that the Ca(2+) receptor is the dominant regulator of parathyroid cell hyperplasia in addition to parathyroid hormone secretion. The clinical implications of these findings suggest that controlling Ca(2+) receptor activity with calcimimetic compounds could be sufficient to manage secondary hyperparathyroidism in CRI.     

Can cancer cells transform normal host cells into malignant cells?

A human prostate tumour cell line, LNCaP C4-2, when injected into athymic male nude mice, produced tumours containing: (1) only human cancer cells similar to those injected; (2) only murine stromal cells containing abnormal chromosome constitutions; or (3) both human prostate cancer cells similar to those injected and the transformed murine stromal cells with altered chromosome constitutions. Karyotypic analysis of murine metaphases from all the host-derived tumours showed mostly pseudodiploid chromosome constitutions, with multiple copies (amplification) of mouse chromosome 15 and the absence of a typical Y chromosome. Fluorescence in situ hybridization analysis of these murine cells, using a biotin-labelled total human DNA painting probe, further demonstrated the absence of human DNA and the presence of only mouse metaphase and interphase cells in these transformed stromal cells. These results suggest that cancer cells are capable of inducing neoplastic transformation in stromal cells of the host organ by some, as yet unknown, epigenetic mechanism(s).     

Physiological anticoagulants and activated protein C resistance in childhood stroke

Immunological and functional protein S, protein C and antithrombin III levels and anticoagulant responses to activated protein C were measured in 24 patients with stroke in childhood. No hereditary deficiencies were found. The protein S levels in healthy controls of younger age did not differ from the adult levels. For optimal screening of protein S deficiency, measurements using functional as well as immunological assays are recommended. Appropriate criteria for the diagnosis of the deficiencies must be carefully applied if unnecessary anxiety and inappropriate treatment of children are to be avoided.     

Evaluation of attempted prevention of unexpected infant death in very high-risk infants by planned health care

Three hundred and ninety-six babies born in Sheffield between 1982 and 1990 identified as being at "very high risk" of unexpected infant death by means of a scoring system, received an intensive programme of health care including a case discussion between a paediatrician, the GP and the health visitor held in the family doctor's surgery, weekly visits from the health visitor and informal hospital admission. Significantly fewer sudden unexpected infant deaths occurred in this group than were expected by logistic regression anlysis or occurred in the best available control group with comparable scores ( p = 0.024). Problems in evaluation include identification of an adequate control population, ethical difficulties in introducing a controlled study when the programme is already perceived as effective, and the calculation of "expected death rates". The results of this study indicate that very energetic programmes of intervention may prevent some deaths in vulnerable infants.     

BRCA1 promoter region hypermethylation in ovarian carcinoma: a population-based study

There is a clear association between germ-line BRCA1 mutations and inherited ovarian cancer; however, the association between BRCA1 mutations and sporadic ovarian cancer remains ambiguous. The frequency of BRCA1 promoter hypermethylation as an epigenetic means of BRCA1 inactivation was determined for a large, population-based cohort of ovarian cancer patients. BRCA1 promoter hypermethylation was determined by methylation-specific restriction digestion of tumor DNA, followed by Southern blot analysis and confirmed by methylation-specific PCR. BRCA1 promoter hypermethylation was observed in 12 of 98 ovarian tumors. BRCA1 methylation status of the primary tumor was conserved in six recurrent tumors after interim chemotherapy. None of the 12 tumors with BRCA1 promoter hypermethylation demonstrated BRCA1 protein expression by immunohistochemistry. BRCA1 methylation was only seen in ovarian cancer patients without a family history suggestive of a breast/ ovarian cancer syndrome. Therefore, the 12 BRCA1 methylated tumors represented 15% (12 of 81) of the sporadic cancers analyzed in this study. Although the clinical significance of BRCA1 promoter hypermethylation is yet to be determined, promoter hypermethylation may be an alternative to mutation in causing the inactivation of the BRCA1 tumor suppressor gene in sporadic ovarian cancer.     

Fibromatosis of bone in children

Radiographs, computed tomograms, and radionuclide bone scans were obtained preoperatively in three children with fibromatosis involving the bones and soft tissues of the extremities. Two of the children had identical scar-like bone lesions of the proximal tibia, which, to the authors' knowledge, have not been reported before in this disease. The lesions recurred in two children.