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Biomedical subjects

L Baker

Publications and source records attributed to L Baker.

At least 163 records · Page 9Linked to original sources
PubMed1987

Psychiatric symptomatology in language-impaired children: a comparison.

This paper reports a detailed comparison of two groups of children from the same psychiatric clinic, one with a delay in language development and an age- and sex-matched control group with no such delay. The language-delay group was highly likely to have either a diagnosis of mental retardation or infantile autism. Very few psychiatric symptoms occurred more frequently in the language-delay group than in the comparison group, and those that did were characteristic of retarded or autistic children. The language-delay group was more likely to have other developmental abnormalities, hearing impairment, and evidence of central nervous system dysfunction.

Adolescent↗
PubMed1987

Clinical significance of childhood communication disorders: perspectives from a longitudinal study.

A group of 202 children who were referred for evaluation of communication disorders were also evaluated for psychiatric and learning disorders at two points in time. High rates of both psychiatric and learning disorders were found at initial evaluation, and even higher rates were found at follow-up 3 to 4 years later. Recovery from communication disorder occurred in approximately one fourth of the cases and varied widely depending on the type of disorder involved. Poor psychiatric outcome could be predicted by the presence and severity of initial disorders of language comprehension and expression, and by certain environmental factors (such as psychosocial stress). The high prevalence of linguistic, psychiatric, and development disorders at follow-up for the children in this study suggests the need for close monitoring of children with early communication impairments.

Attention Deficit Disorder with Hyperactivity↗
PubMed1987

Differential diagnosis of hyperactivity.

"Hyperactivity" is a common symptom presenting to pediatricians, child psychiatrists, child neurologists, and many others who deal with grade-school-age children. This paper discusses the differential diagnosis of hyperactivity. The diagnostic process in making the differential diagnosis of hyperactivity is outlined, and the relevant diagnostic tools are described. The psychiatric, developmental, physical, neurological, psychosocial, and environmental factors to be considered in making the differential diagnosis are reviewed.

Attention↗
PubMed1987

Detection of HIV antigen and specific antibodies to HIV core and envelope proteins in sera of patients with HIV infection.

The sera of well-characterized populations were examined for three markers of human immunodeficiency virus (HIV) infection; HIV antigen (HIV Ag), and antibodies to HIV envelope (gp41) and core (p24) proteins. Of 563 serum samples tested, 251 were from HIV-infected patients diagnosed as having AIDS manifested by opportunistic infections (AIDS-OI), AIDS-associated Kaposi's sarcoma (AIDS-KS), or AIDS-related complex (ARC). One hundred seventy-six specimens tested were from asymptomatic high-risk individuals, and 136 were from heterosexual control subjects or patients with non-AIDS-related disease. None of the 136 control individuals tested had HIV Ag or HIV antibodies to either p24 or gp41. Of the 427 HIV-seropositive individuals, 99% to 100% were positive for gp41 antibodies to HIV. In contrast, the seroprevalence of p24 antibodies to HIV varied from 23% to 83% and appeared to be inversely associated with the severity of the patients' clinical symptoms. When specimens were analyzed for the presence of HIV Ag, in seropositive individuals the prevalence rate for this marker was lowest (1.4%) in asymptomatic individuals and highest (50%) in the AIDS-OI diagnosed group. Also, 240 cases with AIDS-KS, AIDS-OI, and ARC and the group of asymptomatic high-risk individuals were analyzed for T helper/T lymphocytes (T4) cell number and T4/T8 ratio; only one (2.0%) HIV Ag-positive case showed a T4 cell number greater than 400 and a normal T4/T8 ratio. These studies appear to demonstrate a direct correlation between the presence of HIV Ag and the severity of clinical complications of HIV infection.

Antibodies, Viral↗
PubMed1987

Hypoglycemic syndrome in infancy and childhood. A surgeon's perspective.

Persistent, severe hypoglycemia due to inappropriate or excessive insulin secretion is an infrequent but devastating metabolic emergency in infancy and childhood. The primary therapeutic goal is to normalize blood glucose levels and to prevent the catastrophic sequelae of permanent brain damage and mental retardation due to refractory hypoglycemia. Overall, the use of diazoxide, the mainstay of medical treatment, has proved disappointing and has led to the reevaluation of aggressive, early surgical intervention. Currently, subtotal (80% to 90%) pancreatectomy is the most widely used operative procedure in the treatment of hyperinsulinism. It is, however, still associated with a relatively high failure rate, particularly in neonates or during early infancy when either nesidioblastosis or islet cell hyperplasia-both diffuse proliferative beta-cell disorders-is the most common cause of inappropriate insulin secretion. In these cases, "total" or "near-total" pancreatectomy may be necessary to control the hypoglycemic crisis.

Child↗
PubMed1987

Attention-deficit disorder in children: the role of the nurse practitioner.

Attention-deficit disorder is a relatively common syndrome; it is probably the behavior disorder of childhood that primary care practitioners most frequently see. This article describes 1) the clinical picture, subtypes and possible etiologic factors involved in the disorder; 2) the diagnostic evaluation of the child who presents with symptoms suggestive of this syndrome; 3) the natural history of the disorder and its relationship to other disorders of childhood, adolescence and adult life; and 4) the management of the disorder. The nurse practitioner can play a major role in evaluating these children, in designing a proper multimodality treatment program, in making referrals for appropriate types of intervention and in monitoring the results of this multimodality therapeutic program over time.

Attention Deficit Disorder with Hyperactivity↗
PubMed1987

Chronic severe constipation. Prospective motility studies in 25 consecutive patients.

The purpose of this study was to determine the patterns of gastrointestinal and anal sphincter motility in 25 consecutive patients with severe constipation. Three patterns of abnormal motility were observed in 68% of the patients: (a) isolated anal sphincter dysfunction (20%), (b) a generalized disorder of gastrointestinal motility (24%), and (c) rectosigmoid dysfunction (24%). The remaining patients had either a previously unrecognized primary disorder leading to constipation or the irritable bowel syndrome. Duration of symptoms, laxative usage, or other historical features failed to distinguish each of the groups. Anal sphincter dysfunction was diagnosed by demonstrating impaired sphincter relaxation during rectal distention. Generalized motor disorders were diagnosed by demonstrating impaired colonic and esophageal function together with an abnormality in gastric emptying. Rectosigmoid dysfunction was manifest by an impaired rectosigmoid motor response to feeding without evidence of other organ dysfunction. These studies indicate that a high percentage of patients with more severe degrees of constipation have a serious but sometimes treatable disorder of bowel function, rather than the irritable bowel syndrome.

Adult↗
PubMed1986

Superoxide-mediated modification of low density lipoprotein by arterial smooth muscle cells.

Extracellular superoxide was detected in cultures of monkey and human arterial smooth muscle cells as indicated by superoxide dismutase inhibitable reduction of cytochrome c. Superoxide production by these cells in the presence of Fe or Cu resulted in modification of low density lipoprotein (LDL). The degree of LDL modification was directly proportional to the rate of superoxide production by cells. Superoxide dismutase (100 micrograms/ml), and the general free radical scavengers butylated hydroxytoluene and butylated hydroxyanisole (50 microM), inhibited Fe- and Cu-mediated modification of LDL by monkey smooth muscle cells, while catalase (100 micrograms/ml) and mannitol (25 mM) had no effect. The chelators desferrioxamine and diethylenetriamine pentaacetic acid completely inhibited Fe- and Cu-promoted modification of LDL, while EGTA had no inhibitory effect. EDTA stimulated Fe-promoted modification in the 1-100 microM range while inhibiting Cu-mediated modification of LDL. LDL modified by smooth muscle cells in the presence of 10 microM Fe or Cu stimulated [14C]oleate incorporation into cholesteryl ester by human macrophages and murine J774 cells to a degree comparable to that produced by acetylated LDL. LDL incubated with smooth muscle cells and metal ions in the presence of superoxide dismutase failed to enhance macrophage cholesteryl ester accumulation. Thus, arterial smooth muscle cells in culture generate superoxide and modify LDL by a superoxide-dependent, Fe or Cu catalyzed free radical process, resulting in enhanced uptake of the modified LDL by macrophages. Neither hydroxyl radicals nor H2O2 are likely to be involved. Superoxide-dependent lipid peroxidation may contribute to biological modification of LDL, resulting in foam cell formation and atherogenesis.

Animals↗
PubMed1986

Impaired chemotaxis and neutrophil (polymorphonuclear leukocyte) function in glycogenosis type IB.

Polymorphonuclear leukocyte (PMN) function was investigated in two patients with glycogen storage disease type IB and neutropenia. Glycogen storage disease type IB was documented by liver biopsy and a normal amount of latent glucose-6-phosphatase activity. Patient A had stomatitis, skin infections, and septicemia; patient B had respiratory infections, periodontitis, and oral candidiasis. Absolute neutrophil counts ranged from 114 to 2580/mm3. Diminished and delayed migration of PMN into a skin "window" occurred in B. Random and directed PMN migration under agarose toward f-Met-Leu-Phe, pepstatin A, and zymosan-activated serum were severely diminished in both patients. At 10(-7) M f-Met-Leu-Phe, mean random and directed migration were 52 and 23% (A, n = 3) and 48 and 13% (B, n = 4) of controls. These results were independent of incubation time and chemoattractant concentration. Patients' PMN had diminished quantitative nitroblue tetrazolium reduction compared to controls. B had a significant defect in PMN bactericidal activity with Escherichia coli with less than 0.2 log killing at 2 h. These results further characterize the defect in PMN migration reported by Beaudet et al. (J Pediatr 97:906, 1980). The finding of other abnormalities of PMN function suggests a metabolic defect in the neutrophil which may be related to the microsomal membrane defect in hepatocytes in glycogen storage disease type IB.

Adolescent↗
PubMed1986

Paramagnetic enhancement of cerebral lesions with gadolinium-DTPA.

Magnetic resonance imaging (MRI) was performed on 30 patients with cerebral symptoms before and after intravenous gadolinium-DTPA (Gd-DTPA) administration. T1 and T2 weighted images were obtained in all patients. Fifty abnormalities were found in 27 patients. The post-contrast images revealed lesions not seen on pre-contrast scans in 6 patients. Also, the post-contrast images showed a change in morphology of the lesions in 15 that provided additional information for assessing the abnormality. The Gd-DTPA did not obscure any of the lesions seen on pre-contrast scans. Gd-DTPA improves conspicuity, helps characterize and delineate the extent of lesions and increases the sensitivity for detection of cerebral abnormalities.

Adult↗
PubMed1986

The combination measles, mumps, rubella and varicella vaccine in healthy children.

A clinical trial was conducted to compare the combination measles, mumps, rubella, varicella vaccine (MMRV) and the standard measles, mumps, rubella vaccine and subsequent varicella vaccine (MMR + V) in 15 to 17 month old healthy children. Both the MMRV and MMR + V schedules stimulated virtually 100% seroconversion for all component viruses. Mean antibody titers were similar for each virus component in the two vaccine groups. Clinical reactivity post immunization was also similar with 25-29% morbilliform rashes, 12-25% mild papulovesicular (varicella) rashes, and 12.5-18% temperature elevations above 101 degrees F. Antibodies to measles, mumps, and rubella viruses were persistent in 8/10 originally seronegative MMRV vaccinees and 5/5 MMR + V recipients tested. On MMRV recipient had a household exposure to chickenpox during the year postvaccination that resulted in a subclinical boost in varicella antibody titer. Two children in the MMR + V group had close varicella exposures: one developed mild varicella (20 lesions). There were no known exposures to natural measles, mumps, or rubella. Three of four MMRV vaccinees with low titer antibody to varicella prior to immunization had greater than four-fold rises in antibodies. The combination measles, mumps, rubella, varicella vaccine is an immunogenic, safe and cost effective approach to varicella immunization of healthy children.

Antibodies, Viral↗
PubMed1986

Combination measles, mumps, rubella and varicella vaccine.

A comparative clinical trial was conducted in 15- to 17-month-old healthy children to compare an investigational combination measles, mumps, rubella, varicella (MMRV) vaccine v standard measles, mumps, rubella vaccine followed 6 weeks later with the varicella (MMR + V) vaccine. Both the MMRV and MMR + V vaccine schedules stimulated virtually 100% seroconversion for all component viruses. Mean antibody titers were similar for each virus component in the two vaccine groups. Clinical reactivity postimmunization was also similar with 25% to 29% morbilliform rashes, 12% to 25% mild papulovesicular (varicella) rashes, and 12.5% to 18% temperature elevations above 38.3 degrees C (101 degrees F). Antibodies to measles, mumps, and rubella viruses were persistent at 1 year of follow-up in both groups. Varicella antibody was persistent in 8/10 originally seronegative MMRV vaccinees and 5/5 MMR + V vaccine recipients tested. One MMRV vaccine recipient had a household exposure to chickenpox during the year postvaccination that resulted in a subclinical boost in varicella antibody titer. Two children in the MMR + V vaccine group had close varicella exposures; mild varicella (20 lesions) developed in one. There were no known exposures to natural measles, mumps, or rubella. Three of four MMRV vaccinees with low titer antibody to varicella prior to immunization had greater than fourfold increases in antibodies after vaccination. The combination MMRV vaccine is an immunogenic, safe, and cost-effective approach to varicella immunization of healthy children. Continued work is needed to select the appropriate dose of varicella component, to assure higher persistence rate of varicella antibody.

Antibodies, Viral↗
PubMed1985

Genomic heterogeneity of AIDS retroviral isolates from North America and Zaire.

In an analysis of the genomic variation of AIDS retroviral isolates from patients living in New York, Alabama, and Zaire, restriction maps were constructed by using seven enzymes, each known to cleave the proviral DNA more than once, in conjunction with Southern blot analysis. The maps of LAV, HTLV-III, and ARV-2 as deduced from their published nucleotide sequences were included in this analysis. The results demonstrated that (i) several "signature" restriction sites were common to all isolates; (ii) with the exception of LAV and HTLV-III, the North American and European isolates were all different from one another and showed no geographical specificity; (iii) the African isolates as a group were more diverse than those from North America and Europe; and (iv) the genomic variability was concentrated within the env gene.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Exercise as a provocative test in early renal disease in type 1 (insulin-dependent) diabetes: albuminuric, systemic and renal haemodynamic responses.

The value of exercise as a provocative test for early renal disease in Type 1 (insulin-dependent) diabetes was re-evaluated. Three carefully characterized groups of males were studied: 10 non-diabetic controls, 16 diabetic patients (group 1) with normal urinary albumin excretion (less than 15 micrograms/min) and 14 Albustix-negative diabetics (group 2) with increased urinary albumin excretion (15-122 micrograms/min). Assignment to a study group was made on the basis of three 24-h urine collections, and the groups were well matched for age, weight, height, and serum creatinine concentration. The two diabetic groups were similar with regard to duration of disease (13 +/- 6 versus 16 +/- 3 years), metabolic control (HbA1c: 8.4 +/- 1.4 versus 8.7 +/- 1.3%) and degree of diabetic complications (beat-to-beat variation and retinopathy). An exercise protocol of 450 and 600 kpm/min workloads was employed. In the resting state group 2 patients had elevated systolic blood pressure compared with the normal subjects (132 +/- 13 versus 119 +/- 9 mmHg), and their glomerular filtration rate was significantly reduced compared with group 1 (123 +/- 19 versus 138 +/- 15 ml/min per 1.73 m2, p less than 0.05). During exercise the urinary albumin excretion rate increased significantly in all three groups (normal subjects: 6 +/- 0.7 to 8 +/- 1.3 (microgram/min); group 1: 6 +/- 0.6 to 9 +/- 1 microgram/min and group 2: 48 +/- 10 to 113 +/- 23 micrograms/min), the relative increase being higher in group 2 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Radioimmunoassay and enzyme-linked immunoassay of antibodies directed against lymphadenopathy-associated virus (LAV) proteins larger than the core protein (P24).

The acquired immunodeficiency syndrome (AIDS) may be transmitted by blood transfusions and by blood products from donors who have been infected with the lymphadenopathy-associated virus (LAV). Such donors may generally be identified on the basis of a positive test for antibodies-against LAV proteins. We have already described an anti-LAV assay based on the use of crude virus-infected tissue culture medium, which avoids elaborate, expensive and potentially hazardous virus purification steps. This test was operationally specific for antibodies to the approximately 24 kD core protein of the virus (P24; Neurath et al. J. Virol. Methods 11, 75, 1985). Molecular exclusion chromatography of crude LAV antigen preparations allows separation of most of P24 from larger proteins of LAV (PL). PL and 125I- or beta-lactamase-labeled anti-LAV were used as reagents for radioimmunoassay (RIA)--or enzyme-linked immunoassay (ELISA)--inhibition tests to detect antibodies directed predominantly against PL (anti-PL). Among 257 individuals belonging to groups at high risk of developing AIDS, 117 (45.5%) were positive for anti-PL and 108 (42%) for anti-P24, respectively. The 2 individuals among 600 random blood donors found to be anti-P24-positive in the preceding study also had anti-PL in their serum. Sera from 500 additional blood donors were screened for anti-PL and 1 of these was positive. The implication of these findings for screening of blood donors is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Radioimmunoassay and enzyme-linked immunoassay of antibodies to the core protein (P24) of human T-lymphotropic virus (HTLV III).

Human T-cell lymphotropic viruses designated HTLV III or LAV are considered to represent the causative agent(s) of the acquired immunodeficiency syndrome (AIDS). Individuals who have been infected with these viruses may generally be identified on the basis of a positive serological test for antibodies against the protein components of these viruses. Purified viruses or viral proteins have been utilized for developing such tests. Since AIDS may be transmitted by blood transfusion and by blood products, screening of donors for antibodies to HTLV III/LAV has become a necessity. Such screening may be facilitated by the application of assays based on the use of crude virus-infected tissue culture media avoiding elaborate, expensive and potentially hazardous virus purification steps. Serum specimens were mixed with an appropriate dilution of an HTLV III-infected tissue culture-derived fraction, obtained by precipitation with polyethylene glycol 6000 and treatment with Tween 80 and tri-n-butylphosphate (to disrupt virus particles), and incubated with polystyrene beads coated with antibodies to HTLV III/LAV (anti-HTLV III). Subsequently, washed beads were incubated with either 125I- or beta-lactamase-labeled anti-HTLV III. The radioactivity or enzymatic activity associated with the beads was proportionate to the quantity of HTLV III antigen originally added to the beads. The presence of anti-HTLV III in serum specimens resulted in decreased antigen binding and thus in decreased radioactivity or diminished beta-lactamase activity associated with the beads. The test was specific for antibodies to the approximately equal to 24 kDa core protein of HTLV III. The prevalence of these antibodies (given in parentheses) in distinct populations was as follows: random blood donors (0.33%); hemophiliacs (36.4%); random homosexual males (25.1%); homosexual males preselected on the basis of positive markers for infection with hepatitis B virus (50%); and those with persistent lymphadenopathy (70%).

Acquired Immunodeficiency Syndrome↗