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Biomedical subjects

H F Krous

Publications and source records attributed to H F Krous.

At least 37 records · Page 2Linked to original sources

Decreased kainate receptor binding in the arcuate nucleus of the sudden infant death syndrome.

The human arcuate nucleus is postulated to be homologous to ventral medullary surface cells in animals that participate in ventilatory and blood pressure responses to hypercarbia and asphyxia. Recently, we reported a significant decrease in muscarinic cholinergic receptor binding in the arcuate nucleus in victims of the sudden infant death syndrome compared with control patients that died of acute causes. To test the specificity of the deficit to muscarinic cholinergic binding, we examined kainate binding in the arcuate nucleus in the same database. We assessed 3H-kainate binding to kainate receptors with tissue receptor autoradiography in 17 brainstem nuclei. Analysis of covariance was used to examine differences in binding by diagnosis, adjusted for postconceptional age (the covariate). Cases were classified as SIDS, 47; acute control, 15; and chronic group with oxygenation disorder, 17. (Acute controls are infants who died suddenly and unexpectedly and in whom a complete autopsy established a cause of death). The arcuate nucleus was the only region in which there was a significant difference in the age-adjusted mean kainate binding between the SIDS group (37+/-2 fmol/mg tissue) and both the acute controls (77+/-4 fmol/mg tissue) (p < 0.0001) and the chronic group (69+/-4 fmol/mg tissue) (p < 0.0001). There was a positive correlation between the density of muscarinic cholinergic and kainate binding in the SIDS cases only (R = 0.460; p = 0.003). The neurotransmitter deficit in the arcuate nucleus in SIDS victims involves more than one receptor type relevant to carbon dioxide and blood pressure responses at the ventral medullary surface.

Arcuate Nucleus of Hypothalamus↗

Correlation of renal biopsy and radionuclide renal scan differential function in patients with unilateral ureteropelvic junction obstruction.

To understand better the relationship among radionuclide renal scan differential function, renal histology and the outcome of pyeloplasty we performed ipsilateral renal biopsies in a series of patients undergoing primary pyeloplasty. A total of 17 consecutive patients with unilateral ureteropelvic junction obstruction underwent renal biopsy at the time of pyeloplasty. Biopsies were examined systematically after sections were stained with hematoxylin and eosin, periodic acid, Schiff, Jones modified silver or Masson trichrome stains, and they were reviewed by 1 pathologist. Biopsy results were correlated with preoperative and postoperative radionuclide renal scan differential functions. Patient age ranged from 1 month to 7 years (mean 19.8 months). Renal biopsy was abnormal in 6 kidneys, of which 5 had a preoperative differential function of less than 33%. None of these kidneys had evidence of postoperative improvement in renal function on followup scans despite a technically successful result. All remaining 11 kidneys had normal biopsies and a preoperative differential function of greater than 44%. We conclude from these data that patients with ureteropelvic junction obstruction with a differential function of less than 35% have a high probability of significant histological changes on biopsy and a low probability of postoperative improvement in differential function.

Biopsy↗

Molecular identification of viruses in sudden infant death associated with myocarditis and pericarditis.

A subset of infants dying suddenly and unexpectedly have myocarditis with or without pericarditis found at autopsy. To address whether viruses known to cause infantile myocarditis and pericarditis might be present in such infants, we examined myocardium, liver and skeletal muscle for the presence of genomic sequences from adenovirus, cytomegalovirus, enterovirus and echovirus 22/23 in infants enrolled in a comprehensive evaluation protocol. We studied eight infants who died suddenly and unexpectedly with histologic evidence of myocarditis and/or pericarditis detected at postmortem examination. One infant with myocarditis and pericarditis had adenovirus genome detected in the myocardium. In an additional infant with severe pericarditis alone, enterovirus genome was detected in the liver. Although echovirus 22/23 has been associated with myopericarditis in young infants, no previous studies have used molecular methods to search for the genomic sequences of these viruses in clinical samples. No echovirus 22/23 genome was detected in the patients reported here. The significance of enterovirus and adenovirus genome in the tissues of two patients dying suddenly and unexpectedly remains speculative but raises the possibility that pathogenic viruses may cause little or no clinical symptoms and yet be contributory to sudden death in young infants.

Adenoviridae↗

Fertility index analysis in cryptorchidism.

We report on 226 male patients with cryptorchidism 6 months to 16 years old who underwent open testis biopsy at orchiopexy or orchiectomy at Children's Hospital and Health Center from 1986 to 1990. A total of 355 specimens was obtained. Tissues were preserved in Bouin's solution and examined on light microscopy for fertility index measurements. Several biopsies prepared using Bouin's preserved paraffinized tissue and glutaraldehyde preserved semi-thin cut tissue were found to have comparable fertility index measurements. Of 184 patients with unilateral undescended testes 87 also underwent biopsy on the contralateral descended testis. A total of 42 patients had bilateral undescended testes. Age matched comparisons were made between fertility index measurements of the undescended testes and those previously reported of normal testes. Additional case matched comparisons of fertility indexes were made in those children who underwent biopsy of the undescended testis and its descended mate. Statistical analysis was performed using the independent Student t-test. When comparing undescended to descended testes, there was no significant difference in the fertility index of patients 1 year old or younger but fertility index differences were statistically significant in all of the other age groups. Fertility index measurements were significantly decreased from normal expected values in all age groups with unilateral cryptorchidism and in all but the 13 to 18-month-old group with bilateral cryptorchidism. The fertility index in the descended testis was similar to previously reported normal testis measurements in boys between 13 months and 6 years old. Our data suggest that potential fertility in the cryptorchid testis may be significantly impaired compared to normal testicular fertility regardless of patient age at the time of discovery of the undescended testis. The fertility index of the descended mates of unilateral undescended testes may also be somewhat impaired in certain age groups. Orchiopexy in the first year of life may be indicate to preserve available fertility potential.

Adolescent↗

Female infant with oncocytic cardiomyopathy and microphthalmia with linear skin defects (MLS): a clue to the pathogenesis of oncocytic cardiomyopathy?

A infant girl had red stellate skin lesions on the cheeks and neck, and mildly short palpebral fissures. Her skin abnormality was typical of microphthalmia with linear skin defects (MLS), a newly recognized syndrome consisting of congenital linear skin defects and ocular abnormalities in females monosomic for Xp22. She died suddenly and unexpectedly at age 4 months; the cause of death was ascribed to oncocytic cardiomyopathy. Oncocytic cardiomyopathy occurs only in young children, who present with refractory arrhythmias leading to cardiac arrest. The coexistence of two rare conditions, one of which is mapped to the X chromosome, and an excess of affected females with oncocytic cardiomyopathy, make it likely that oncocytic cardiomyopathy is also X-linked, with Xp22 being a candidate region. Overlapping manifestations in the two conditions (ocular abnormalities in cases of oncocytic cardiomyopathy and arrhythmias in MLS) offer additional support for this hypothesis.

Abnormalities, Multiple↗

Esthesioneuroblastoma presenting as an orbital mass in a young child.

A 3-year-old boy presented with uniocular proptosis and ophthalmoplegia. Investigation revealed a mass involving the right orbit with extension into the left orbit and paranasal sinuses, and intracranial extension involving both frontal lobes. Biopsy of an enlarged cervical node and the intranasal mass revealed esthesioneuroblastoma. This tumor has been reported rarely in a child this age, and only 12 case reports document patients under 10 years of age. The presentation as an orbital mass is previously unreported and must now be considered in the differential diagnosis of proptosis in childhood. The usual clinical, radiological, and pathological features of olfactory esthesioneuroblastoma are reviewed.

Child, Preschool↗

Pulmonary vasculitis with hemorrhage in anaphylactoid purpura.

We report a 14-year-old female with anaphylactoid purpura (AP) who developed pulmonary hemorrhage with acute vasculitis on lung biopsy. She improved with pulse methylprednisolone, daily prednisone and ventilatory assistance. Pulmonary vasculitis is a rare but serious manifestation of AP.

Adolescent↗

Adenovirus myocarditis: retrospective diagnosis by gene amplification from formalin-fixed, paraffin-embedded tissues.

Understanding the pathogenesis of viral myocarditis is linked to the availability of sensitive assays to detect viruses in clinical material. Recent advances in molecular techniques permit direct detection of viral-specific nucleic acid in tissue samples. This report describes a protocol for DNA extraction and amplification of adenovirus genome from formalin-fixed, paraffin-embedded human tissues that detects as little as 10 copies of viral genome in a background of 0.5 micrograms of human DNA. This sensitive assay permitted the examination of archived tissues to establish a retrospective diagnosis of adenoviral myocarditis in two pediatric patients.

Adenovirus Infections, Human↗

Presence or absence of trisomy 11 is correlated with histologic subtype in congenital mesoblastic nephroma.

Fluorescence in situ hybridization utilizing a probe for the alpha satellite repeat sequence on chromosome 11 was used to detect variations in the number of chromosomes 11 in 24 formalin-fixed, paraffin-embedded congenital mesoblastic nephromas. Evidence of trisomy 11 was found in nearly half of the tumors. More importantly, the presence of trisomy 11 was associated with the cellular histologic variant of this tumor.

Chromosomes, Human, Pair 11↗

Molecular and phenotypic variability in the congenital alveolar proteinosis syndrome associated with inherited surfactant protein B deficiency.

Congenital alveolar proteinosis (CAP) is an often fatal cause of respiratory failure in term newborn infants, which has been associated with a genetic deficiency of surfactant protein B (SP-B) as a result of a frameshift mutation (121ins2) in a family with three affected siblings. In the index cases the deficiency of SP-B was associated with qualitative and quantitative abnormalities of the surfactant proteins A and C. Immunostaining for lung surfactant proteins and a search for the 121ins2 mutation by restriction enzyme analysis of DNA extracted from paraffin-embedded lung tissue was performed for 7 additional affected infants from 6 families, bringing to 10 the total number of patients with CAP who have been studied. In six infants, the surfactant protein immunostaining pattern was similar to that of the index cases. Of these, three patients were homozygous for the 121ins2 mutation; one was a compound heterozygote with the 121ins2 in one allele and a different mutation in the other; and three patients lacked the mutation in both alleles. One infant had an abundance of SP-B, suggesting phenotypic heterogeneity in CAP. Lung ultrastructural abnormalities, such as a reduced number of lamellar bodies, absent tubular myelin, and basal secretion of surfactant lipids and proteins, suggest a significant derangement of surfactant metabolism. The phenotypic heterogeneity in infants with CAP raises the possibility that variable degrees of SP-B deficiency may be more common than previously suspected.

Female↗

Unbalanced translocation resulting in the loss of the chromosome 17 short arm in an osteoblastoma.

We report results of the first cytogenetic study of an osteoblastoma. Cells from the tumor were characterized by a three-way unbalanced translocation involving chromosomes 15, 17, and 20. As a consequence of the translocation, most of one chromosome 17 short arm appears to have been lost. This loss suggests the possibility that loss of 17p DNA sequences may be involved in early changes leading to neoplastic proliferation of osteoblasts.

Bone Neoplasms↗

Fibrous hamartoma of infancy presenting as a perspiring neck mass.

An unusual case of fibrous hamartoma of infancy is reported. This lesion presented as a gradually enlarging, perspiring left neck mass in an eight month old male. Histologic examination revealed the characteristic features of this entity, with the additional finding of eccrine gland hyperplasia. In a review of the literature, we found no other reports of this unique histologic finding or clinical presentation.

Hamartoma↗

Mammalian epithelial cell line kit for detection of Clostridium difficile toxin.

The performance characteristics of a mammalian epithelial (MEP) cell line kit (Cytotoxi Test; Advanced Clinical Diagnostics, Toledo, Ohio) for the detection of Clostridium difficile toxin was compared with that of conventional tissue culture assays with human embryonic lung (HEL) cells in shell vials and human foreskin fibroblasts (HFFs) in test tubes. One hundred forty-nine stool samples were tested. The MEP cells were at least as sensitive as the HEL cells for use in C. difficile toxin detection. Results for the MEP cells were also obtained considerably more rapidly than those for HEL cells when the cells were examined at 4 and 24 h and then every 24 h for up to 5 days. Approximately one-third of all positive MEP cells were detected at 4 h and 95% were detected by 48 h. In comparison, in the HEL shell vial monolayers, only 6% of the positive cells were detectable at 4 h and 76% were detectable at 48 h. The times for C. difficile toxin-induced cytotoxicity in HFF cells were similar to those in HEL cells. Shell vials carrying HEL cell monolayers (ViroMed Laboratories Inc., Minnetonka, Minn.) are a sensitive and reliable commercial source for the detection of C. difficile toxin, although they cannot detect C. difficile as rapidly as the Cytotoxi test with the MEP cell monolayers.

Bacterial Proteins↗

Common pulmonary vein atresia: the role of extracorporeal membrane oxygenation.

Common pulmonary vein atresia is a rare form of cyanotic congenital heart disease in which the pulmonary veins join to form a blind confluence that does not communicate with the heart or the major systemic veins. Twenty-one cases have been reported since the lesion was first described in 1962; only two patients with this lesion have survived. Over a 4-year period, common pulmonary vein atresia was diagnosed in five newborns referred to the San Diego Regional Extracorporeal Membrane Oxygenation Program. All five improved dramatically as a result of venoarterial bypass. Congenital heart disease was diagnosed at autopsy in the initial case and by cardiac ultrasound and/or catheterization in the others. Surgical repair was attempted in three neonates; all three required continued extracorporeal membrane oxygenation support postoperatively because of pulmonary hypertension and severe pulmonary parenchymal disease. One infant died of respiratory insufficiency at 3 months of age. The other two survived and were discharged from the hospital. The diagnostic and therapeutic dilemmas posed by this lesion and the life-saving potential for extracorporeal membrane oxygenation in this rapidly fatal cardiac anomaly are the bases of this report.

Apgar Score↗

A review of sudden infant death syndrome.

This chapter defines sudden infant death syndrome (SIDS) and provides a brief review of the history, current knowledge, pathology, and possible mechanisms of death. The authors conclude with considerations of other selected causes of sudden, unexpected infant death.

Cause of Death↗

Second report of a translocation involving 19q13.4 in a mesenchymal hamartoma of the liver.

Cytogenetic study of a mesenchymal hamartoma of the liver detected a balanced translocation between chromosomes 11 and 19 in a 6-month-old male whose constitutional karyotype was normal. The chromosome 19 breakpoint, 19q13.4, appears to be identical to one of the breakpoints identified in the only other mesenchymal hamartoma studied with cytogenetic methods.

Chromosome Banding↗