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Biomedical subjects

H J Hoffman

Publications and source records attributed to H J Hoffman.

At least 19 recordsLinked to original sources
PubMed1992

A randomized controlled trial of perioperative rifampin/trimethoprim in cerebrospinal fluid shunt surgery.

A randomized, double-blind, placebo-controlled trial of perioperative rifampin-trimethoprim was undertaken at the Hospital for Sick Children from March 1984 to October 1987, in which 243 patients undergoing 300 cerebrospinal fluid (CSF) shunting procedures were randomized into groups including treatment with rifampin/trimethoprim and placebo, and then followed for a minimum of 2 years. Patients were stratified prior to randomization into those with and those without meningo-myeloceles having first insertions of their shunts, and those having revisions. Patients could be entered into the study more than once, but always received the same treatment regimen once allocation had taken place. Among the patients receiving antibiotics there was an infection rate of 12%, versus 19% among patients receiving placebo. Among the surgical procedures, the rates were 9% and 15%, respectively. Because these rates of infection were a substantial increase over the rate of 7.5% overall for the few years prior to implementation of the study, and well over any acceptable rate of infection, the study was stopped before statistical significance was reached. However, had the study continued, and the proportions of patients becoming infected remained constant, we would have been able to achieve a statistically significant difference in rates of infection, and therefore demonstrate a benefit of rifampin/trimethoprim as prophylaxis against shunt infection. Methodological problems encountered in this and other studies of prevention of CSF shunt infection will be discussed.

Adolescent↗
PubMed1992

Maternal alpha-2-macroglobulin levels and fetal growth in Guatemala.

Maternal serum alpha-2-macroglobulin (alpha 2M) levels were measured at the time of delivery in 244 women in the central highlands of Guatemala. Significantly higher alpha 2M levels were found in thin women and in poor women. In multiple regression analysis controlling for gestational age, race, sex, maternal triceps skinfold thickness and socioeconomic status, high alpha 2M levels were significantly associated with decreased birthweight. These findings agree with those in a predominantly black population in the United States and extend the relationship between alpha 2M and decreased birthweight to a developing country.

Biomarkers↗
PubMed1992

Brain tumors in children and adolescents--III. Effects of radiation and hormone status on intelligence and on working, associative and serial-order memory.

The effects on intelligence and memory of two post-surgical conditions (radiation treatment, hormone deficiency and supplementation) were explored in 46 children and adolescents with tumors in a variety of brain sites. Verbal intelligence, but not non-verbal intelligence, varied positively with age at radiation treatment. Memory for word meanings was unrelated to either radiation history or to hormone status. Severe deficits in serial position memory occurred with impaired hormone function and an older age at tumor onset. Severe deficits in working memory were associated with a history of radiation and a principal tumor site that involved thalamic/epithalamic brain regions. Radiation treatment and hormone status affect later cognitive function in children and adolescents with brain tumors. Although the greater vulnerability of the verbal intelligence of the younger radiated child and the serial order memory of the child with later tumor onset and hormone disturbances remain to be explained, and although the form of the relationship between radiation and tumor site is not fully understood, the data highlight the need to consider the cognitive consequences of pediatric brain tumors according to a set of markers that include maturational rate, hormone status, radiation history, and principal site of the tumor.

Adolescent↗
PubMed1992

Detection and management of gangliogliomas in children.

Forty-two children treated for gangliogliomas were reviewed to identify the best methods of detection and management. Thirty-two of the tumors were supratentorial, four infratentorial, and six were in the spinal cord. Twenty-five patients presented with seizures; the mean duration of symptoms was 5 years in contrast to 1 year in non-seizure patients. Of 31 children studied by computed tomography (CT), calcification in the tumor lesion was found in 19. Magnetic resonance imaging (MRI) showed abnormal high-signal intensity on T2 imaging in six of eight patients. All patients underwent surgical resection and were diagnosed pathologically. Twenty-four patients had total resection, and 14 underwent temporal lobectomies including hippocampectomy. The management of this tumor remains surgical resection without the need for any adjuvant therapy.

Adolescent↗
PubMed1992

Elevated levels of midtrimester maternal serum alpha-fetoprotein are associated with preterm delivery but not with fetal growth retardation.

OBJECTIVE: Our objective was to determine if the low birth weight associated with unexplained elevations of midtrimester maternal serum alpha-fetoprotein levels is due to prematurity or to fetal growth retardation. STUDY DESIGN: Rates of preterm delivery and fetal growth retardation were analyzed according to incremental maternal serum alpha-fetoprotein levels in 5555 women, predominantly white, who were screened for neural tube defects (group 1) and 843 women, predominantly black, with risk factors for low birth weight (group 2). Statistical methods included chi 2, t tests, analysis of variance, and regression analysis. RESULTS: In both groups increasing levels of maternal serum alpha-fetoprotein are significantly associated with preterm delivery but not with fetal growth retardation. The preterm delivery rate increased in each group from 8% at levels less than 0.5 multiples of the median to 18.1% (p less than 0.001) at levels greater than or equal to 2.5 multiples of the median in group 1 and 28.1% (p = 0.01) in group 2. CONCLUSIONS: Women with unexplained elevations of maternal serum alpha-fetoprotein are at increased risk for preterm delivery but not fetal growth retardation. Because of the wide availability of maternal serum alpha-fetoprotein screening, women at increased risk for preterm delivery can be identified in the midtrimester of pregnancy.

Black People↗
PubMed1992

Blood pressure, growth retardation, and preterm delivery.

The effect of various levels of both diastolic and systolic blood pressure at various times during pregnancy on the rates of intrauterine growth retardation (IUGR) and preterm delivery (PTD) were determined. Low systolic and diastolic pressures were associated with both IUGR and PTD, as were high pressures. Low pressures tended to be associated with spontaneous preterm deliveries, whereas high pressures were associated with more indicated preterm deliveries.

Blood Pressure Determination↗
PubMed1992

Maternal serum folate and zinc concentrations and their relationships to pregnancy outcome.

To evaluate the relationship between folate and zinc, and its effect on pregnancy outcome, maternal serum folate and zinc concentrations were determined at 18 and 30 wk gestation in a defined population of 285 pregnant women as part of a large-scale study to identify risk factors for fetal growth retardation (FGR). These results were correlated with birth weight and Apgar scores of newborn infants and with maternal infections during the perinatal period. A weak linear relationship was observed between maternal serum folate and zinc concentrations at 30 wk gestation. Folic acid supplementation had favorable effects on birth weight and Apgar scores of newborns, and reduced prevalence of FGR and maternal infections. No significant correlation was found between serum zinc concentration and birth weight of infants. The concept that folic acid supplementation has an adverse effect on maternal zinc nutriture and pregnancy outcome was not supported.

Adult↗
PubMed1992

Neuroimaging for investigation of seizures in children.

In patients with structural abnormalities of the brain with poor seizure control by medication, epilepsy surgery becomes a very important tool for seizure control. Numerous radiological imaging studies are being used for studying the abnormality in order to aid in the planning of surgery. Included in the radiological imaging modalities are CT, MR, and Xenon CT, SPECT and PET. In future, perfusion and diffusion MR as well as MEG mapping will become part of the investigative tool. The following paper is a summary and discussion of the usefulness of different modalities in different disease entities with a proposal for the method of investigation.

Brain Damage, Chronic↗
PubMed1992

Focal midbrain tumors in children.

The clinical and neuroradiological features of focal midbrain tumors in 12 children are described, and the results of their surgical management are presented. Patients with a focal midbrain tumor usually exhibit either symptoms and signs of raised intracranial pressure caused by an obstructive hydrocephalus (50%) or symptoms and signs caused by pressure on the tegmentum and cerebral peduncles. The lesions are confined to the tectal plate or tegmentum with possible extension upward to the thalamus and downward to the pons, displacing but not invading these structures. The edges of the tumor are well defined, and the large majority have a solid consistency with intense regular enhancement after intravenous contrast. Radical resection is hardly ever feasible in brain stem tumors, but in this series, significant reduction of the tumor mass was obtained in 75% of the patients, with no surgical mortality and minimal surgical morbidity and with the majority of patients showing clinical improvement postoperatively. All tumors were nonpilocytic, low-grade astrocytomas. Six patients received adjunctive radiotherapy. The mean follow-up period is 2.5 years, and all patients are alive and doing well. We conclude that focal midbrain tumors in children appear to be a distinct subgroup of brain stem tumors and are very amenable to surgical resection with an excellent long-term prognosis.

Adolescent↗
PubMed1992

Sudden infant death syndrome and maternal smoking.

Data from Missouri for the period 1980 to 1985 suggest a dose-response relationship between smoking during pregnancy and the incidence of sudden infant death syndrome (SIDS). However, data from the National Institute of Child Health and Human Development SIDS Cooperative Epidemiological Study did not support a dose-response relationship. Neither the Missouri data nor the Cooperative Study data support a relationship between the age of occurrence of SIDS and smoking during pregnancy.

Age Factors↗
PubMed1992

The lowest birth-weight infants and the US infant mortality rate: NCHS 1983 linked birth/infant death data.

The National Center for Health Statistics Linked Birth and Infant Death Data Set, 1983 birth cohort, shows that infants weighing less than 750 g, comprising only 0.3% of all births, account for 25% of deaths in the first year of life and for 41% of deaths in the first week. If interventions had prevented the death of these very small babies, the infant mortality rate would have been 8.3 per 1000 live births instead of 10.9, and the Black/White mortality differential would have been reduced by 25%.

Black or African American↗
PubMed1992

Aggressive surgical management of craniopharyngiomas in children.

The cases of 50 patients with craniopharyngioma operated on at The Hospital for Sick Children in Toronto between January, 1975, and December, 1989, are reviewed. All patients were under 18 years of age (mean 9.39 years). Headaches, endocrine deficiencies, and visual deficits were the most common symptoms on admission. Forty-five patients underwent what was considered by the surgeon to be total excision of their tumor, and five had subtotal excision. Tumors recurred in 17 patients (mean time of recurrence 32.6 months after surgery). One patient died in the postoperative period and three have been lost to follow-up study. Of the remaining 46 patients, 28 are leading a normal or nearly normal life, although all are receiving endocrine replacement and some have required help to overcome mild deficits in memory or visual acuity. Twelve patients are able to function reasonably well and attend school despite being hampered by intellectual or visual deficits or problems with weight control; four have a significant handicap, and two have died.

Actuarial Analysis↗
PubMed1992

Long-term results after lateral canthal advancement for unilateral coronal synostosis.

The procedure of lateral canthal advancement was carried out to correct unilateral coronal synostosis in 39 consecutive patients at The Hospital for Sick Children during a 20-year period. Thirty-seven children were available for follow-up study, and results were considered to be good or excellent in 81% of them. Liberation of the supraorbital margin and release of stenotic skull base sutures are crucial for a successful result. The severity of the process and the age of the patient were not restrictive factors in regard to indication for this procedure. Some patients showed a continuous improvement with time. Morbidity was minimal. It is suggested that lateral canthal advancement is the procedure of choice for unilateral coronal synostosis.

Child↗
PubMed1992

Surgical decompression for symptomatic Chiari II malformation in neonates with myelomeningocele.

Between January, 1981, and July, 1991, 17 infants under 1 month of age were admitted to The Hospital for Sick Children with the signs and symptoms of a Chiari II malformation. These patients' presentation included swallowing difficulty (71%), stridor (59%), apneic spells (29%), aspiration (12%), weakness of cry (18%), and arm weakness (53%). Decompression of the Chiari II malformation was performed in all patients, with a time interval between onset of symptoms and surgery ranging from 1 to 121 days. Fifteen patients (88%) remain alive, all of whom have shown a complete recovery. The mean follow-up period in this group of patients was 65 months. Two patients died, one due to respiratory arrest 8 months after decompression and the other because of shunt infection and peritonitis 7 years after decompression. These results support the concept that compressive forces, rather than a primary intrinsic disorder of the brain-stem nuclei, play a crucial etiological role in the development of a symptomatic Chiari II malformation. Early recognition of the symptoms of Chiari II malformation should be followed by immediate decompressive laminectomy in order to promote a prompt and full neurological recovery.

Arnold-Chiari Malformation↗
PubMed1992

Suprasellar and sellar tumors in childhood and adolescence.

Suprasellar and sellar region tumors in children constitute a diverse group of lesions. We advocate an aggressive surgical approach to these tumors for diagnostic and therapeutic purposes. With detailed knowledge of the microneurosurgical anatomy of this region, the neurosurgeon can choose from a number of operative approaches on the basis of tumor size and location. The benefits of radiation therapy for craniopharyngiomas and optic chiasmatic/hypothalamic tumors must be carefully weighted against the substantial long-term risks associated with irradiation of the developing brain in this region. During the next decade, the role of primary chemotherapy for germinoma and adjuvant chemotherapy for optic pathway gliomas will be determined. Also, the role of stereotactic radiation therapy, of great value to some children with recalcitrant tumors in the suprasellar region, may be better defined.

Adolescent↗
PubMed1992

Epidemiology of the sudden infant death syndrome: maternal, neonatal, and postneonatal risk factors.

Infants dying of sudden infant death syndrome (SIDS) constitute the single largest component of postneonatal infant mortality. Many different scientific approaches and hypotheses have been pursued in research studies over the past two decades. The field of epidemiology provides a comprehensive view of risk factors for SIDS with which theories of underlying physiologic defects or other putative causes should conform. Epidemiologic research has a vital role to play in assessing hypotheses derived from other types of studies.

Female↗