Interpretation of alpha-fetoprotein concentrations in cerebrospinal fluid of infants.

BACKGROUND: There are no published reference intervals for concentrations of alpha-fetoprotein (AFP) in the cerebrospinal fluid (CSF) of normal infants. The presence of abnormal concentrations of AFP in plasma or CSF may indicate the presence of a teratoma or a germ cell tumour with yolk sac elements. We measured CSF AFP in infants who did not have malignancy in order to determine its reference intervals. METHODS: AFP was measured in the CSF and/or plasma in 128 infants. Of these, 91 infants had CSF AFP measurements, 94 infants had plasma AFP measurements and in 60 infants AFP concentrations were determined in paired CSF and plasma samples. The patients ranged in age from 1 to 110 days. Both CSF and plasma AFP concentrations were measured by a microparticle enzyme immunoassay using an AxSYM analyser. RESULTS: Using ages corrected for prematurity, the median CSF AFP concentration for babies -69 to 31 days old was 61 kIU/L (5th-95th centile: 2-889 kIU/L), while the median CSF AFP concentration for infants 32 to 110 days was 1.2 kIU/L (5th-95th centile: 0.1-12.5 kIU/L). By age 6 weeks, the concentrations were close to those found in adult plasma and all CSF AFP concentrations from infants with a corrected age over 2 months were <3 kIU/L. CONCLUSION: We have defined reference intervals for CSF AFP concentrations in infants. These results may assist in the diagnosis of CNS tumours, particularly congenital CNS tumours containing yolk sac elements.

Preclinical evaluation of a prostate-targeted gene-directed enzyme prodrug therapy delivered by ovine atadenovirus.

Gene-directed enzyme prodrug therapy (GDEPT) based on the Escherichia coli enzyme, purine nucleoside phosphorylase (PNP), provides a novel strategy for treating slowly growing tumors like prostate cancer (CaP). PNP converts systemically administered prodrug, fludarabine phosphate, to a toxic metabolite, 2-fluoroadenine, that kills PNP-expressing and nearby cells by inhibiting DNA, RNA and protein synthesis. Reporter gene expression directed by a hybrid prostate-directed promoter and enhancer, PSMEPb, was assayed after plasmid transfection or viral transduction of prostate and non-CaP cell lines. Androgen-sensitive (AS) LNCaP-LN3 and androgen-independent (AI) PC3 human CaP xenografts in nude mice were injected intratumorally with an ovine atadenovirus vector, OAdV623, that carries the PNP gene under PSMEPb, formulated with cationic lipid for enhanced infectivity. Fludarabine phosphate was then given intraperitoneally for 5 days at 75 mg/m2/day. PNP expression was evaluated by enzymic conversion of its substrate using reverse phase HPLC. OAdV623 showed excellent in vitro transcriptional specificity for CaP cells. In vivo, expression of PNP persisted for > 6 days after OAdV623 injection and a single treatment provided 100% increase in tumor doubling time and > 50% inhibition of tumor growth for both LNCaP-LN3 and PC3 lines, with increased tumor necrosis and apoptosis and decreased tumor cell proliferation. OAdV623 significantly suppressed the growth of AS and AI human CaP xenografts in mice.

Small bowel perforation in the premature neonate: congenital or acquired?

To determine the potential aetiological factors of small bowel perforation in the premature neonate, we performed a retrospective chart review of those neonates with spontaneous intestinal perforation (SIP) of the small bowel seen in our tertiary paediatric hospital between January 1980 and December 2000. Data were collected on gestational feto-maternal health, medical interventions prior to perforation and the subsequent operative and laboratory findings. There were 23 patients with SIP of the small bowel over the 21-year review; 65% were male. There were 7 twin pregnancies but no cases linked to maternal drug abuse. The median gestational age was 27 weeks, the median birth weight 973 g, 19 neonates required ventilation, 15 steroids and 13 indomethacin. The median age at diagnosis was 7 days, heralded by rapid development of abdominal distension in 22 patients. Surgical intervention in addition to insertion of a peritoneal drain was required in 19 patients. Positive microbiological cultures of blood or peritoneal fluid at operation were documented in 8 patients; 5 grew Staphylococcus epidermidis and 4 Candida species. Perforations were located in the ileum in 20 and the jejunum in 1. Deficiency of the muscularis propria was found in 6 patients. Of the 6 deaths, 2 neonates had significant co-morbidity in addition to extreme prematurity. Small bowel SIP occurs in the premature neonate after the first week of life and usually presents with abdominal distension. Putative risk factors identified included twin gestation, neonatal ventilation, use of steroids and indomethacin, infection with Staphylococcus epidermidis and Candida species and deficiency of enteric smooth muscle.

Karyotype, phenotype and parental origin in 19 cases of triploidy.

The parental origin of triploidy in 19 cases was examined by inheritance of DNA microsatellites and by methylation patterns of SNRPN or PW71 (where parents' blood was unavailable). The fetal and placental morphology on these cases was reviewed. The phenotype of the fetuses with non-mosaic triploidy was assessed in relation to the two types described by McFadden and Kalousek. Of the diandric fetuses three of the six showed mild-to-moderate symmetrical growth retardation and the other three had growth characteristics in accordance with their gestational ages. This study would suggest the fetal triploid 'Type 1' definition be modified to 'well grown to moderate symmetrical IUGR' to allow for such variation. In the digynic fetuses (McFadden/Kalousek Type 2) there were poor growth characteristics with IUGR being more severe and asymmetrical. The diandric fetuses were as common as digynic fetuses in this series. The ratio of diandric to digynic specimens was 11:8 but if only fetal specimens (not embryos or mosaic children) were included the ratio was 6:5. Many diandric conceptions end as partial moles but later in gestation diandric fetuses may be well grown. It is proposed that there may be a survival barrier for diandric fetuses early in gestation (possibly based on the proportion of vascularised placental villi), although once this is passed the diandric fetuses are comparatively more viable and better grown than digynic fetuses. In the XXY triploid fetuses, 5/6 had hypoplastic or ambiguous external genitalia (two were recorded as of female phenotype) as has been reported previously. In these, the gonadal histology was testicular in all the diandrics but in the single digynic XXY case, sex reversal was complete with normal uterus and Fallopian tubes and the gonads were histologically ovaries. Two triploid/diploid mosaics were proven to be due to digyny. The probable cause is delayed incorporation of the second polar body into a blastomere and there was evidence of identical alleles from the same sperm being present in both diploid and triploid cells. In one of these triploid/diploid mosaics in which there was a termination of pregnancy (TOP) after prenatal karyotyping the diploid cell line had trisomy 16 which was not evident in the triploid line. This trisomy was probably of post-zygotic origin and we suggest the fetus was rescued by the prominence of the triploid line.

Bisphosphonates and nephrocalcinosis in a rabbit leg lengthening model: a histological and therapeutic comparison.

We performed a comparison of the effects of two bisphosphonates, pamidronate and zoledronic acid, on regenerate bone mineral content in distraction osteogenesis in an immature rabbit model. Single dose zoledronic acid was found to be 18 times more potent at producing an increase in bone mineral content than pamidronate per mg/kg of drug infused at surgery. Histological examination of all rabbit kidneys was performed at trial completion. Nephrocalcinosis was identified in 14 of 20 kidneys of rabbits infused with pamidronate, but was not detected in the 20 kidneys of those rabbits infused with zoledronic acid. A further 20 kidneys from rabbits given a second dose of zoledronic acid were also found to be free of signs of nephrocalcinosis. Three of 40 control kidneys exhibited signs of nephrocalcinosis. The increased potency of zoledronic acid allowed us to give one-tenth the dose of pamidronate, with increased therapeutic efficacy and no evidence of nephrocalcinosis.

Intravenous pamidronate reduces osteoporosis and improves formation of the regenerate during distraction osteogenesis. A study in immature rabbits.

We examined the effect on bone mineral density (BMD) of a single dose of 3 mg/kg of the bisphosphonate, pamidronate (Novartis) in distraction osteogenesis in immature rabbits. Seventeen rabbits (9 control, 8 given pamidronate) were examined by dual-energy x-ray absorptiometry. There was a significant increase in the BMD in the pamidronate group compared with the control animals. The mean areal BMD (g/cm2) in the bone proximal and distal to the regenerate was increased by 40% and 39%, respectively, compared with the control group (p < 0.05). The BMD of the regenerate bone was increased by a mean of 43% (p < 0.05). There was an increase of 22% in the mean area of regenerate formed in the pamidronate group (p < 0.05). Histological examination of bone in nine rabbits (5 control, 4 pamidronate) showed an increase in osteoblastic rimming and mineralisation of the regenerate, increased formation of bone around the pin sites and an increase in the cortical width of the bone adjacent to the regenerate in the rabbits given pamidronate. Pamidronate had a markedly positive effect. It reduced the disuse osteoporosis normally associated with lengthening using an external fixator and increased the amount and density of the regenerate bone. Further study is required to examine the mechanical properties of the regenerate after the administration of pamidronate.

Noncervicofacial atypical mycobacterial lymphadenitis in childhood.

BACKGROUND/PURPOSE: Atypical mycobacterial (AM) lymphadenitis is common in children but rarely occurs outside the cervicofacial region. The authors report their experience in the diagnosis and management of noncervicofacial AM lymphadenitis. METHODS: A retrospective review was conducted of cases diagnosed at our institution between January 1976 and December 1999, based on positive culture of atypical mycobacteria or consistent histology with supportive skin testing. RESULTS: Thirty-seven patients were identified over the 23-year review period. The median age was 4.3 years (range, 8 months to 13 years and 5 months), with 19 boys and 17 girls. The median duration of symptoms was 4 weeks, and the most commonly affected sites were the inguinal region (n = 17), axilla (n = 8), and lower limb (n = 6). Preceding local trauma was described in 10 patients and a viral illness in 4. Laboratory culture for atypical mycobacteria was positive in 22, and skin testing suggestive in 21 and equivocal in 2. Treatment was by excision in 28 and drainage with or without curettage in 9. At a median follow-up of 19.7 months, disease had recurred in 4 patients, none of whom had been treated initially by excision. CONCLUSIONS: Atypical mycobacterial infection is an uncommon cause of noncervicofacial lymphadenitis in children. It typically presents with a 4-week history of painless regional lymphadenopathy that may follow penetrating trauma. If untreated, the overlying skin becomes involved with a violaceous discoloration, and ulceration may occur. Definitive treatment involves complete surgical excision, preferably before suppuration extending beyond the involved lymph nodes.

Anterior horn cell disease and olivopontocerebellar hypoplasia.

To date, fewer than 30 cases of anterior horn cell disease with associated olivopontocerebellar hypoplasia have been reported. We describe five patients and review the literature on this uncommon disorder. In addition to a syndrome of progressive spinal muscular atrophy similar to that seen in Werdnig-Hoffmann disease, this disorder is characterised by hypoplasia of the olivary nuclei, pons, and cerebellum. Additional clinical features may include dysmorphism, abnormal eye movements, stridor, congenital joint contractures, and enlarged kidneys. Pontocerebellar hypoplasia may be associated with posterior fossa cystic malformations, cerebral atrophy, and a demyelinating neuropathy.

Catalytic differences between porcine blastocyst and placental aromatase isozymes.

Two isozymes of porcine aromatase, the placental and the blastocyst forms, were expressed in CHO cells using the mammalian cell transfection method. Using an 'in-cell' assay (a 3H-water release method), catalytic parameters of the porcine placental aromatase were found to be very similar to those of the human enzyme; however, the activity of the blastocyst isozyme was found to be one-thirtieth that of the placental isozyme. Product isolation assay (using testosterone as the substrate) revealed that the major steroid products were 17beta-estradiol and 19-nortestosterone. The product ratio of estradiol/19-nortestosterone was found to be 94 : 6 for the porcine placental form, 6 : 94 for the porcine blastocyst form, and 92 : 8 for the human wild-type aromatase. Therefore, the porcine blastocyst aromatase isozyme catalyzes mainly androgen 19-desmethylation rather than aromatization. In addition, inhibition profile analyses on the placental and blastocyst isozymes were performed using three steroidal inhibitors [4-hydroxyandro-stenedione (4-OHA), 7alpha-(4'-amino)phenylthio-1, 4-androstandiene-3,17-dione (7alpha-APTADD), and bridge (2, 19-methyleneoxy) androstene-3,17-dione (MDL 101,003)], and four nonsteroidal inhibitors [aminoglutethimide (AG), CGS 20267, ICI D1033, and vorozole (R83842)]. While the two isozymes of porcine aromatase share 93% amino-acid sequence identity, our results indicate that the two porcine aromatase isozymes have distinct responses to various aromatase inhibitors.

Laparoscopic bladder 'wrap' technique for repair of vesicoureteric reflux in a porcine model.

PURPOSE: The aim of this study was to determine if vesicoureteric reflux (VUR) can be successfully corrected laparoscopically by a bladder "wrap" technique in a pig model. METHODS: In 15 female piglets (mean weight, 22.5 kg) bilateral VUR was created by an open technique (11 grade 3, 2 each of grades 2 and 4). Eight weeks later (range, 4to 16 weeks) VUR was confirmed by fluoroscopic cystogram, and unilateral laparoscopic correction was performed. The contralateral ureter was used as a control. The bladder was emptied, and a 3F ureteric catheter was inserted on the repair side. Four 11-mm ports were inserted transperitoneally. The ureter was dissected to the ureterovesical junction (UVJ). Commencing at the UVJ, 2 (n = 9) or 3 (n = 6) black silk sutures were placed through the bladder muscle on either side of the ureter creating a bladder wrap around the distal 2 to 4 cm of ureter. At a mean of 16 weeks (range, 4 to 24 weeks) cystograms were repeated. The animals were killed the bladder and ureters underwent histopathology examination. RESULTS: VUR was corrected in 12 animals (80%). There was persistence of VUR in 2 and ureteric obstruction in 1. The wrap was intact in all animals. CONCLUSIONS: Laparoscopic correction of VUR by the bladder wrap technique is successful in pigs. Long-term follow-up studies will determine if this will be a satisfactory alternative surgical treatment for correction of VUR in children.

Lymphopoietic cancer and other major causes of death among petrochemical researchers: an update.

This study updates lymphopoietic cancer (LHC) mortality statistics and other major causes of death through 1992 for 13,188 petrochemical researchers employed between 1964 and 1986. Significant deficits of deaths were observed for all causes, all cancers, ischaemic heart disease and all external causes. The subcategory of 'all other LHC' was elevated among males in an exposure class containing scientists and engineers. This finding was statistically significant based on national but not state comparison rates. Poisson regression analyses showed that increasing exposure classes were not associated with LHC, but a relationship was noted for total years worked. A non-significant increase in breast cancer among females was also observed but was concentrated among the lowest exposure class. This study and other similar investigations suggest various subcategories of LHC deaths are marginally elevated among chemical researchers and engineers. Evidence for a work-related LHC hazard for this population, however, has not been identified.

Functional characterization of 102-amino acid-deleted form of human aromatase (delta102-aromatase).

A truncate form of human aromatase cDNA that corresponds to the recently identified rat cortical type aromatase mRNA variant (Yamada-Mouri et al., J. Steroid Biochem. Molec. Biol., 60: 325-329, 1997) has been generated, and the amino-terminus deleted form of the enzyme has been expressed in CHO cells. The resulting product lacking 102 residues from the N-terminus of aromatase (i.e. 102-aromatase) showed an extremely low enzyme activity using an 'In-cell' assay. A strong aromatase activity, however, was observed for the delta102-aromatase using an in vitro method on the solublized preparations. The in vitro activity was dependent on both incubation time and NADPH concentration as well as inclusion of NADPH-cytochrome P450 reductase in the assay mixture. The average turnover rate of aromatization of the reconstituted delta102-aromatase was 6.8 min(-1). The results of the immunosuppression assay suggested that delta102-aromatase still holds the epitope interactive to MAb3-2C2, a monoclonal antibody raised agaist human placental aromatase P450. Furthermore, the IC50 values of MAb3-2C2 were determined to be 24 and 23 microg/ml for the whole homogenate and the 105,000 x g precipitate fractions prepared from the truncated aromatase expressing cells, respectively, whereas an IC50 of 1.3 microg/ml was shown for the full-length human aromatase. These results indicate that the delta102-aromatase P450 can be expressed and is catalytically competent as the full-length enzyme, but the epitope structure for the monoclonal antibody MAb3-2C2 is altered from that of the native enzyme. In addition, the intracellular distribution of delta102-aromatase may be different from that of the wild-type enzyme, explaining why very low activity was measured using an 'In-cell' assay.

Testicular and paratesticular tumours in children: 30 years' experience.

BACKGROUND: Testicular or paratesticular tumours in children are rare, making it difficult to achieve the best management for these life-threatening diseases. The aim of this study is to review patients during a 30-year period with these tumours and assess clinical aspects to improve management. METHODS: The records of 68 patients from 1967 to 1996 were reviewed with respect to age at diagnosis, affected sites, presentation, clinical diagnosis, operation, pathology and prognosis. RESULTS: The most common presentation was a painless scrotal mass (84%). The most common testicular tumour was mature teratoma (n = 27) followed by yolk sac tumour (n = 17). Thirteen patients had paratesticular rhabdomyosarcoma. Two teratocarcinomas, three leydig cell tumours, two sertoli cell tumours, one granulosa cell tumour, one fibroma, one gonadoblastoma, and one secondary tumour from acute myeloid leukaemia were found also. Testis-sparing surgery was performed in 21 of 33 patients with benign tumours (27 teratoma, three leydig cell tumours, two sertoli cell tumours, one fibroma), which caused no recurrence. Only two patients with rhabdomyosarcoma and one with mixed germ cell tumour died of their disease. CONCLUSION: Recent combined therapy with surgery and chemotherapy against primary testicular and paratesticular tumours has improved prognosis. Testis-sparing surgery should be considered for benign tumours.

A fatal case of angiostrongyliasis in an 11-month-old infant.

An 11-month-old boy developed flaccid quadriparesis after two months in Fiji, and was transferred to Australia, where a diagnosis of postinfectious myelitis was made. Despite peripheral blood eosinophilia, eosinophils were not detected in the cerebrospinal fluid, and an infective aetiology was not identified. The patient died of progressive bulbar dysfunction. At autopsy, numerous nematodes, identified as Angiostrongylus cantonensis, were seen in vessels of the lungs, brain and spinal cord, associated with pulmonary abscesses and eosinophilic meningitis. A notable feature was the presence of adult nematodes in the lung.

Localized microcystic lymphatic malformations--ultrasound diagnosis.

Microcystic lymphatic malformations present with a wide variety of clinical manifestations that may make diagnosis difficult. We present four patients with microcystic lymphatic malformations that have been confirmed by both histology and ultrasound appearance. Five further cases of microcystic lymphatic malformations with unusual presentations, in which ultrasound was used to support the diagnoses, are then presented. The use of ultrasound as a tool to aid in the diagnosis of microcystic lymphatic malformations is then discussed and compared with other investigative techniques.

Planning a scientific session.

A long-time member of the California Dental Association Council on Scientific Sessions explains what goes into planning the educational program at a major scientific meeting--from the selection of speakers to on-site arrangements and the role of staff.

Fatal granulomatous amoebic encephalitis caused by Balamuthia mandrillaris.

Granulomatous amoebic encephalitis caused by Balamuthia mandrillaris is rare (63 human) cases reported worldwide) and fatal. We report a case in a five-year-old boy who had previously been well. For 18 months, he had had a slowly progressive, granulomatous mid facial lesion, but despite extensive investigation definitive diagnosis was made only with the acute onset of neurological signs in the last two weeks of life, when a brain biopsy specimen revealed amoebic trophozoites and cysts. Infection with B. mandrillaris should be considered in the differential diagnosis of chronic skin lesions with non-specific granulomatous histopathology and negative microbiological test results.

A maternally transmitted lethal neonatal progeroid syndrome with prominent genitourinary and gastrointestinal features.

Twin brothers and their maternal uncle with a previously undescribed neonatal progeroid syndrome are presented. In addition to progeroid features, they had pseudo-obstruction of the urinary and gastrointestinal tracts, severe leucocytosis, liver dysfunction, and low complex III and IV in muscle but not in liver. Previously described neonatal progeroid syndromes and syndromes featuring pseudo-obstruction are discussed. The two most likely aetiological mechanisms are an X linked single gene disorder or a mitochondrial disorder. The evidence for these possibilities is presented.

Diverse function of aromatase and the N-terminal sequence deleted form.

The diverse function of human placental aromatase including estradiol 6alpha-hydroxylase and cocaine N-demethylase activity are described, and the mechanism for the simultaneous metabolism of estradiol to 2-hydroxy- and 6alpha-hydroxyestradiol at the same active site of aromatase is postulated. Comparison of aromatase activity is also made among the wild type and N-terminal sequence deleted forms of human aromatase which are recombinantly expressed in Escherichia coli. Aromatase cytochrome P450 was reconstituted and incubated with [6alpha,7alpha-(3)H2,4-(14)C]estradiol, 7-ethoxycoumarin, and [N-methyl-(3)H3]cocaine. 6Alpha-hydroxy[7alpha-(3)H,4-(14)C]estradiol was isolated as the metabolite of estradiol and the 3H-water release method based on the 6alpha-3H label was established. The initial rate kinetics of the 6alpha-hydroxylation gave Km of 4.3 microM, Vmax of 4.02 nmol min(-1) mg(-1), and turnover rate of 0.27 min(-1). Testosterone competed dose-dependently with the 6alpha-hydroxylation and showed the Ki of 0.15 microM, suggesting that they occupy the same binding site of aromatase. The deethylation of 7-ethoxycoumarin showed Km of 200 microM, Vmax of 12.5 nmol min(-1) mg(-1) and turnover rate of 1.06 min(-1). The N-demethylation of cocaine was analysed by the 3H-release method, giving Km of 670 microM, Vmax of 4.76 nmol min(-1) mg(-1), and turnover rate of 0.49 min(-1). All activity was dose-responsively suppressed by anti-aromatase P450 monoclonal antibody MAb3-2C2. The N-terminal 38 amino acid residue deleted form of aromatase P450 was expressed in particularly high yield giving a specific activity of 397 +/- 83 pmol min(-1) mg(-1) (n = 12) of crude membrane-bound particulates with a turnover rate of 2.6 min(-1).