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Biomedical subjects

H F Krous

Publications and source records attributed to H F Krous.

At least 55 records · Page 3Linked to original sources
PubMed1992

Congenital pulmonary alveolar proteinosis: failure of treatment with extracorporeal life support.

Pulmonary alveolar proteinosis, a rare disease in neonates, is characterized by the accumulation of insoluble amorphous material within the alveoli. We describe two pairs of siblings with pulmonary alveolar proteinosis in two otherwise unaffected families. All four patients were term neonates in whom severe pulmonary failure developed within hours after birth; three had mature lung profiles. Radiographic lung markings were characterized by an early granular pattern followed by lung opacification. All patients were treated with extracorporeal life support for periods of 212 to 381 hours, but none survived. Life spans ranged from 16 to 190 days. We speculate that pulmonary alveolar proteinosis in neonates results from a genetic defect in surfactant processing that may not be amenable to conventional or unconventional therapies, including extracorporeal life support.

Extracorporeal Membrane Oxygenation↗
PubMed1991

Carotid artery reconstruction following neonatal extracorporeal membrane oxygenation.

Although reconstruction of the right common carotid artery (RCCA) in neonatal extracorporeal membrane oxygenation (ECMO) patients is intuitively attractive, there is little known about prolonged arterial cannulation and how it may affect subsequent vascular repair. A histological study of RCCA segments from neonatal ECMO patients was performed, so that cannulation technique and catheter design could be optimized before proceeding with arterial reconstruction. Circumferential transmural necrosis (CTN) was found in 25 of 31 (80%) arteriotomy specimens in comparison with 2 of 9 (20%) more proximal carotid specimens; the remaining specimens in each group demonstrated either focal subintimal or focal transmural necrosis. CTN was more common in patients with longer ECMO runs (96 +/- 5.9 versus 75 +/- 5.6 hours, P = .009; arteriotomy site), but was independent of cannula size, birthweight, and gestational age. Eleven patients have undergone RCCA reconstruction. Doppler flow studies at 4 to 7 months of follow-up in five patients demonstrated slightly higher right-sided versus left-sided peak systolic, end-diastolic, and mean flow velocities. No neurological or developmental problems could be attributed to vascular reconstruction. In conclusion, RCCA reconstruction is technically feasible, but due to the high prevalence of CTN at the arteriotomy site, excision of this segment is recommended at the time of arterial repair.

Carotid Arteries↗
PubMed1990

Hepatoblastoma characterized by trisomy 20 and double minutes.

Karyotypic study of two hepatoblastomas revealed trisomies for chromosome 20 and the presence of double minutes (dmin). These cases are the second and third examples of trisomy 20 in hepatoblastoma and are the first examples of dmins in this rare childhood tumor.

Carcinoma, Hepatocellular↗
PubMed1990

Germ cell neoplasms of head and neck soft tissues: a pathologic spectrum of teratomatous and endodermal sinus tumors.

Germ-cell neoplasms, in particular teratomas with immature and mature somatic type tissues, are some of the most commonly found tumors in children. Approximately 5% of these neoplasms appear in one of several extracranial sites in the head and neck region. This study reports the clinical, pathologic and immunohistochemical findings in six germ-cell neoplasms occurring in the neck and facial areas. A mass was recognized at birth in five children, and the sixth patient was 2 1/2 years old at diagnosis. Four of the six neoplasms contained one or another element of endodermal sinus tumor; two of these had a mixed pattern of endodermal sinus tumor and teratoma. The other two cases were purely teratomas. The serum alpha-fetoprotein was known to be elevated in three children whose tumors had endodermal sinus elements; it returned to normal level in two of the children, but remained high in the one fatal case. Placental alkaline phosphatase and alpha-fetoprotein were demonstrated immunohistochemically in two of the three cases, with available tissue containing endodermal sinus tumor. Teratomatous metastases in ipsilateral cervical lymph nodes were found in one patient with a pure teratoma; that patient is disease-free one year after surgery. Only nine previous examples of endodermal sinus tumor have been reported in the head and neck region, exclusive of the central nervous system. There is one other case in the literature of a congenital cervicothyroidal teratoma with metastatic disease. These six neoplasms illustrate the clinical and pathologic spectrum in this nosologically homogeneous, but morphologically diverse, category of tumors.

Alkaline Phosphatase↗
PubMed1990

Do angiomas of the nasal septum exist?

Juvenile nasopharyngeal angiofibromas (JNA) by definition originate in the nasopharynx. Vascular tumors arising in the nasal cavity can easily be mistaken for JNA, when the correct diagnosis is hemangioma or angiofibromatous polyp. We present a case that illustrates this problem, an 11-year-old boy with a unilateral anterior nasal cavity mass associated with recurrent epistaxis. At surgery, the mass was found to arise from the anterior nasal septum and was removed easily with minimal bleeding. The initial pathologic interpretation was JNA. After extensive review of the specimen, however, the diagnosis of hemangioma was made. Similar tumors have been reported as being JNA that have been simple to remove with minimal blood loss. JNA is associated with more severe blood loss, is more difficult to expose surgically and has a higher risk of recurrence than other nasal tumors. Therefore, JNA needs to be distinguished from anterior nasal cavity masses.

Child↗
PubMed1990

Cervicofacial mycobacterial adenitis in children: endemic to San Diego?

Nontuberculous mycobacteria (NTM) are an important cause of cervicofacial lymphadenitis in children. A dramatic increase has been seen in confirmed cases of NTM lymphadenitis in San Diego in the past few years. This report encompasses a span of 2 years 9 months, during which 22 children had confirmed NTM infection and another 14 had necrotizing granulomatous lymphadenitis in whom the specific diagnosis of NTM could not be made. This apparent increase in the prevalence of NTM as compared to previous reports in the literature suggests a possible endemic risk for NTM in the San Diego area. These cases are reviewed and our diagnostic and surgical approach to possible NTM infection is described. We also discuss possible explanations for the increasing occurrence of NTM in the San Diego area.

California↗
PubMed1988

Detection of testicular torsion by magnetic resonance imaging in a rat model.

Testicular torsion is one of the most common pediatric urological emergencies. Incorrect or delayed diagnosis contributes significantly to morbidity. We previously have shown that magnetic resonance displays scrotal contents with great detail using hydrogen concentration weighted and T2 weighted images. Sprague-Dawley rats underwent either unilateral 720-degree testicular torsion or a sham procedure. Magnetic resonance images were obtained at intervals with a 3 or 5-inch surface coil. Scans after surgical torsion showed a characteristic spiral distortion of the fascial planes of the spermatic cord, not seen in the sham animals, as well as a decrease in testicular size with prolonged torsion.

Animals↗
PubMed1988

Pathological considerations of sudden infant death syndrome.

The definition of sudden infant death syndrome (SIDS) states the necropsy examination fails to show a cause of death. Nevertheless, continuing pathologic investigation of the infant who dies suddenly and unexpectedly is of paramount importance in order to (1) establish a diagnosis of SIDS with certainty, (2) assist in delineating mechanisms of death in such circumstances, and (3) determine whether other entities, some of which are genetic, are present. In SIDS, the necropsy provides the positive finding of intrathoracic petechiae in a high percentage of cases. It is suggested these hemorrhages are an important clue to terminal upper airway obstruction in SIDS which may be a result of disordered neuroregulatory control of respiration during sleep by the brainstem, and the unique anatomy of the infant's pharynx and surrounding structures. The so-called 'hypoxic tissue markers' suggesting SIDS victims may have suffered prolonged or recurrent apnea have not been confirmed in more recent carefully controlled pathologic studies employing sophisticated methods of histometric analysis.

Autopsy↗
PubMed1987

Magnetic resonance imaging of the cryptorchid testis.

Magnetic resonance imaging was used to evaluate seven patients with undescended testes. In six patients the presence or absence of testicular tissue was predicted correctly prior to surgery. Spermatic cord structures, if present, were accurately visualized in all patients.

Cryptorchidism↗
PubMed1986

Progressive ascending paralysis following administration of intrathecal and intravenous cytosine arabinoside. A Pediatric Oncology Group study.

Two childhood acute myelogenous leukemia (AML) patients receiving intrathecal (IT) and intravenous (IV) cytosine arabinoside (Ara-C) developed progressive ascending paralysis, resulting in death in one patient. Necropsy findings on this patient included spinal cord demyelination characteristic of Ara-C neurotoxicity. An unusual aspect of these two cases was the delay between cessation of IT therapy and the onset of neurologic symptoms. These patients received relatively low total doses of IT Ara-C and standard doses of IV Ara-C. Previous studies have shown that Ara-C equilibrates readily between serum and cerebrospinal fluid; this implies that total IV and IT doses of Ara-C may be additive in relation to development of neurotoxicity. For these reasons, use of IV and IT Ara-C in childhood AML must be approached with greater caution, especially if neurologic abnormalities develop during or after therapy.

Acute Disease↗
PubMed1985

Developmental morphometry of the vagus nerve in the opossum.

Developmental morphology of the vagus nerve has been described for placental but not marsupial mammals such as the opossum which undergo even greater postnatal maturation. In the present study, the cervical vagus nerve of opossums from the seventh postnatal day to the adult were compared after 3% glutaraldehyde immersion, postfixation in osmium tetroxide and staining with uranyl acetate and lead citrate. At 7 days of age, axons were unmyelinated. Only 4 myelinated axons were present at the 25th postnatal day and by 50 days of age only 11% of adult values were reached. The number of Schwann cells increased from 105 at age 7 days up to 640 in the adult. The number of myelin lamellae surrounding the largest axons increased from 9 at 25 days up to 102 +/- 9 at adulthood. In the newborn kitten and rabbit, the number of myelinated vagal fibers comprised 10% (n = 326) and 18% (n = 653), respectively, of that reached in the adult animal. Comparable values are not obtained in the opossum until the 50th postnatal day.

Animals↗
PubMed1985

Diphenylhydantoin-induced hypersensitivity reaction with interstitial nephritis.

A 10-year-old black girl had an episode of diphenylhydantoin(DPH)-induced exfoliative dermatitis, lymphadenopathy, hepatitis, peripheral eosinophilia, and transient renal failure. The findings of specific lymphocyte sensitization of DPH, a clinically typical delayed hypersensitivity reaction, multinucleated histiocytes in the renal interstitium, and negative renal immunofluorescence studies for immune reactants indicate that the child's renal injury was at least partially cell-mediated.

Autoantigens↗
PubMed1985

Vasoactive intestinal polypeptide in cardiac myxoma.

A case of left atrial myxoma is reported in which tumor tissue was found to contain high levels of vasoactive intestinal polypeptide. This finding further supports the concept that myxomas are true neoplasms and may explain some of the poorly understood clinical manifestations of this tumor.

Female↗
PubMed1985

Effect of sleep state and position on the incidence of obstructive and central apnea in infants.

Sixty-four infants with a history of apnea were studied to determine the effects of sleeping position and sleep state (rapid eye movement [REM]) v (non-rapid eye movement [NREM]) on the occurrence of central and obstructive apneas. All-night polysomnographic studies were conducted on each infant, and the spontaneous occurrence of central and obstructive apneic events was determined in the prone, supine, and side positions. Sleeping position did not significantly affect the rate or duration of central or obstructive apneas. Furthermore, neither central nor obstructive apneic episodes were significantly altered by sleep state. These data suggest that, in spite of an ostensible predisposition to upper airway obstruction in the supine position and during rapid eye movement sleep, neither sleeping position nor sleep state appears to affect the rate of duration of apneic events.

Age Factors↗
PubMed1984

Norepinephrine-induced pulmonary petechiae in the rat: an experimental model with potential implications for sudden infant death syndrome.

Autonomic nervous system abnormalities have been implicated in infants dying of or considered at high risk of sudden infant death syndrome (SIDS). In a rat model, norepinephrine (0.02 mg/kg) caused systemic hypertension and numerous pulmonary petechiae, the latter a common finding in SIDS. Petechiae were not seen below the diaphragm. The animals were killed by tracheal occlusion 5 min after the intravenous administration of norepinephrine. The number of pulmonary petechiae was greatly reduced by alpha-adrenergic blockade (phentolamine) and dopaminergic blockade (haloperidol) but not by beta-adrenergic blockade (timolol). A significantly greater reduction of peak mean systemic arterial pressure occurred after alpha-adrenergic blockade than with other blocking agents. It is conceivable that hypoxia-induced endogenous catecholamine release contributes to the pathogenesis of pulmonary petechiae found at necropsy of SIDS victims.

Animals↗
PubMed1984

Sudden infant death syndrome: pathology and pathophysiology.

Sudden infant death syndrome is the most common cause of infant death between the ages of 1 week and 1 year of age and accounts for approximately 50 percent of the deaths of infants between the ages of 2 and 4 months. The unique age distribution and its relationship to sleep particularly characterize SIDS; however, there are other factors, such as maternal smoking, male sex, prematurity or low birth weight, which place an infant at higher risk of SIDS. Intrathoracic petechiae with characteristic microscopic topography are the most frequent pathologic finding. However, pulmonary congestive edema and minor microscopic inflammatory infiltrates are often seen. Stenotic lesions within the coronary arteries supplying the conduction system have been identified in a few SIDS victims; however, current evidence favors respiratory dysfunction as the primary mechanism of death in most SIDS babies. Based upon pathologic, experimental, and clinical observations, an argument can be made that upper airway obstruction, e.g., secondary to obstructive sleep apnea, is one, if not a common, cause of death in SIDS. There are cases in which subtle morphologic evidence suggests SIDS represents the termination of a chronic hypoxic/hypoxemic disorder such as recurrent apnea.

Humans↗
PubMed1984

Epidemiology of sudden infant death syndrome in American Indians.

A 7-year retrospective study of sudden infant death syndrome in Oklahoma Indians failed to support previous observations of a markedly elevated rate among the American Indians compared with the white population. The rate of sudden infant death syndrome in Oklahoma Indians was 2.32/1,000 live births. The rates of sudden infant death syndrome among white infants (1.8/1,000) and black infants (3.11/1,000) were similar to those reported in previous studies. Males had consistently higher rates of sudden infant death syndrome regardless of race.

Black or African American↗