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Biomedical subjects

H Pollack

Publications and source records attributed to H Pollack.

At least 19 recordsLinked to original sources
PubMed1992

Cell-mediated and humoral immune responses in children infected with human immunodeficiency virus during the first four years of life.

OBJECTIVES: To determine whether cell-mediated and humoral immune responses to recall antigens develop in children infected with the human immunodeficiency virus (HIV) and, if so, whether these responses are retained. METHODS: Children infected with HIV and uninfected children born to mothers infected with HIV were compared with respect to lymphoproliferative responses to recall antigens and protective levels of antibody to bacterial toxoids during the first 4 years of life. RESULTS: Children infected with HIV who were enrolled in a prospective study of the natural history of the infection were relatively normal (1) in their lymphoproliferative responses to diphtheria toxoid, tetanus toxoid, and Candida, and (2) in their ability to make protective diphtheria and tetanus antitoxins during the first 2 years of life. During the next 2 years, attrition was noted in both lymphoproliferative and humoral responses. Attrition in response was not necessarily correlated with declining numbers of helper T cells. CONCLUSIONS: These results suggest that both cellular and humoral immune responses develop early in life in most children infected with HIV, while they remain relatively well both clinically and immunologically. Previously reported severe immune deficits in these children were probably attributable to advanced clinical disease when they were first studied.

Age Factors↗
PubMed1992

Early diagnosis of human immunodeficiency virus infection in children less than 6 months of age: comparison of polymerase chain reaction, culture, and plasma antigen capture techniques.

Three techniques were evaluated for their ability to detect human immunodeficiency virus (HIV) in infants from birth to 6 months of age. Polymerase chain reaction (PCR) and HIV cocultivation were of comparable sensitivity, detecting 90% of all positive specimens. Both techniques found positive results in approximately 5% of samples from seroreverting children. Both assays detected HIV in only half of infected newborns, suggesting that this fraction of children was infected during gestation. Plasma p24 antigen was detected in three-fourths of all samples tested but in only half of infected children during the first 2 months of life and 88% of samples from children during the next 4 months. The specificity of p24 antigen detection was 100%.

Cells, Cultured↗
PubMed1992

Delayed recognition of human immunodeficiency virus infection in preadolescent children.

Thirty-two (18%) of 181 children cared for at our institution who were infected with the human immunodeficiency virus type 1 (HIV-1) were first seen, and HIV was diagnosed, when they were 4 years of age and older. Initial complaints or diagnoses for these children included the following: hematologic disorders (5) (3 idiopathic thrombocytopenic purpura, 1 neutropenia, 1 anemia); recurrent bacterial infections (10); Pneumocystis carinii pneumonia (3); developmental delay (1); skin disorders (2) (1 genital wart, 1 chronic zoster); weight loss (3); malignancy (1); and nephropathy (1). Eight children were referred for evaluation because of maternal HIV-1 infection. The risk factors for HIV-1 infection included maternal/perinatal exposure (22), perinatal blood transfusion (6), blood transfusion during infancy (2), and sexual abuse (2). Ten (31%) of the 32 children have subsequently died. The longest survival from perinatal infection was 12 years. HIV-1 infection in children can result in a prolonged clinical latency and can masquerade as other pathologic conditions. The absence of clinical symptoms in older children at risk for HIV-1 infection should not deter HIV testing.

Child↗
PubMed1992

Thrombocytopenia in children infected with human immunodeficiency virus: long-term follow-up and therapeutic considerations.

Among 180 children infected with human immunodeficiency virus (HIV-1), 14 (8%) developed thrombocytopenia during the course of the disease and have been followed for an average period of 18.8 months. Eight of 14 patients had clinical signs of bleeding. Increased levels of anti-platelet IgG antibodies were detected in 86% of patients tested and did not correlate with severity of disease. Eight patients were treated initially with intravenous immunoglobulins (IVIG) and responded with a transient increase in the platelet count of at least 30 x 10(9)/L. Sustained remission could not be achieved in the patients treated with IVIG alone. Corticosteroids were used in 6 patients who became refractory to IVIG and resulted in sustained remission in only one patient. Spontaneous remission of thrombocytopenia occurred in one patient. Ten patients were treated with zidovudine (ZVD) for a period of 3-20 months. Sustained improvement in the platelet counts occurred in only three of the children treated with ZVD.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Lack of correlation between maternal antibodies to V3 loop peptides of gp120 and perinatal HIV-1 transmission. The NYC Perinatal HIV Transmission Collaborative Study.

Recent reports have suggested that maternal antibodies to specific epitopes of the variable region 3 (V3 loop) of gp120 of HIV-1 might protect against perinatal transmission. In an attempt to confirm these findings, sera from 34 HIV-1-seropositive mothers, representing 13 episodes of mother-to-infant transmission and 23 episodes of non-transmission (two mothers had two pregnancies each during the study period), were tested for the presence of antibodies to various regions of the gp120 V3 loop. Synthetic peptides were generated from HIV-1MN. Of the four peptides tested by enzyme-linked immunosorbent assay (ELISA), only antibody to the C53 peptide (Env310-322, principal neutralizing determinant) was present in maternal sera. Antibody to the C53 sequence was present in 11 specimens from transmitting mothers and 21 from non-transmitting mothers (84.6 and 91.3%, respectively, P = 0.6). No reactivity was detected against the C51, C57, or C58 peptide sequences, located on the sides of the V3 loop. In an antigen-limited ELISA, only two specimens from transmitting mothers and two specimens from non-transmitting mothers had detectable 'high-affinity' antibodies to C53 at low antigen concentrations (15.4 and 8.7%, respectively; P = 0.6). Our results do not support previous reports that epitope-specific antibodies to the V3 loop peptides protect against perinatal transmission. Further research is required to determine whether any specific maternal humoral response might influence HIV-1 perinatal transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Disseminated fungal infections in children infected with human immunodeficiency virus.

A retrospective review of charts of 156 human immunodeficiency virus-infected children cared for during a 7.5-year period revealed 11 episodes of disseminateed candidiasis (DC) occurring in 11 patients (7%). All 11 patients developed the fungal infection in the context of advanced human immunodeficiency virus infection. All but one were hospital-acquired, occurring at a mean of 2.3 months after admission. Ten patients had been febrile for more than 14 days before diagnosis. Previous oral thrush and central venous catheters (73 and 82% of patients) represented major predisposing factors for development of DC. Neutropenia (2 of 11 patients) did not represent a major risk factor for DC. Candida albicans was isolated in 9 patients, Rhodotorula minuta in 1 patient and 1 fungal isolate could not be identified. Sources of isolation were blood (8 of 11 patients), central venous catheters (3 of 11) and urine (2 of 11). Lungs (6 of 11 patients), esophagus (5 of 11) and brain, heart and kidneys (3 patients each) were the organs most often involved in DC. Antemortem diagnosis was achieved in only 7 (64%) patients; none of the 4 patients with DC diagnosed postmortem had been treated before death. Seven patients were treated with amphotericin B; 6 of them died but only 3 were treated for more than 7 days of therapy. The overall mortality was 90% (10 of 11 patients). In all 20% of the 50 human immunodeficiency virus-infected children who died at our hospital during the study period had an episode of DC in close proximity to their death. DC was considered the direct cause of death in 4 of 10 children.

Child↗
PubMed1988

Microbiological and clinical significance of a new property of defective lysis in clinical strains of pneumococci.

A pneumococcal isolate that caused relapsing meningitis in a patient infected with human immunodeficiency virus (HIV) was found to display an unusual response to penicillin--rapid death but a striking lack of cellular lysis. This lytic defect was also detected in all four pneumococcal isolates from three additional HIV-infected patients and in more than half of the clinical isolates from patients with bacteremia. In a rabbit model of meningitis, the lysis-defective strain remained cryptic, with a delay of 5 h in the onset of leukocytosis in cerebrospinal fluid. A marked burst of leukocytosis was associated with ampicillin-induced lysis of a lysis-sensitive strain but not of a lysis-defective strain. Pneumococcal clinical isolates have different lytic responses to penicillin; defective lysis may adversely affect the course of meningitis, an observation suggesting that autolysins play a role in modulating infectious diseases.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Localization and protection of kidneys in radiation treatment planning using computed tomography.

Irradiation treatment portals of the upper abdomen must limit the dose to the kidneys. Sparing one-third of the parenchyma of each kidney will prevent late clinical sequelae. One hundred CT scans of the abdomen were studied to evaluate using the vertebrae as landmark for treatment planning. In lateral fields, using the anterior border of the vertebral column as a landmark for the posterior high isodose line will limit treatment to less than 60% (mean 22%) of a single kidney. Placing the edge of an anterior/posterior field 2 cm lateral to the vertebral column will limit the dose to less than 44% of a single kidney (mean 11%).

Adult↗
PubMed1983

NMR imaging of the abdomen at 0.12 T: initial clinical experience with a resistive magnet.

Forty-five patients with a variety of abdominal abnormalities and five normal volunteers were imaged on a 0.12 T resistive nuclear magnetic resonance system. Scans were obtained with saturation-recovery technique and short repetition times. The images reflected both proton density and T1 information. A variety of neoplastic and nonneoplastic disease processes involving the abdomen were imaged. Results suggest that clinically useful images clearly may be obtained at 0.12 T. In addition, saturation-recovery imaging with short repetition rates can detect a wide range of abdominal abnormalities.

Abdomen↗
PubMed1979

Bilateral complete ureteral obstruction secondary to an abdominal aortic aneurysm with perianeurysmal fibrosis: diagnosis by computed tomography.

The sixteenth case of bilateral ureteral obstruction with anuria secondary to an abdominal aortic aneurysm with perianeurysmal fibrosis is presented. The details of this case clearly indicate the need for a combined vascular and urologic approach to patients with this disorder. A complete preoperative evaluation, including excretory urography, retrograde pyeloureterography, aortography and, when indicated, venacavography, may determine renal and vascular abnormalities that will allow a more definitive and successful management of this difficult problem. Furthermore, we believe that the use of computed tomography is an invaluable tool to define this retroperitoneal disease process and its precise relationship to the ureters.

Aged↗
PubMed1978

Liver metastases discovered during high-dose excretory urography.

Liver metastases were discovered in 4 adults during high-dose excretory urography with upper abdominal tomograms. Previous reports in the English literature have noted incidental discovery of hepatic cysts or abscesses during urography, but no documented cases of liver metastases were found. All metastases were visualized as round, lucent, hepatic filling defects during total body opacification. Radiologists performing high dose excretory urography with tomography should routinely scrutinize the hepatogram, because metastases, cysts, or abscesses may be visualized. Final diagnosis of these masses usually depends on additional diagnostic modalities.

Contrast Media↗