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Biomedical subjects

T Hadley

Publications and source records attributed to T Hadley.

At least 19 recordsLinked to original sources
PubMed2000

A prospective cohort study of genetic and perinatal influences in the etiology of schizophrenia.

In this study, we examined whether fetal hypoxia and other obstetric complications (OCs) are related to risk for adult schizophrenia; whether such effects are specific to cases with an early age at onset; and whether the obstetric influences depend on, covary with, or are independent of familial risk. Subjects were 72 patients with schizophrenia or schizoaffective disorder; 63 of their siblings not diagnosed with schizophrenia; and 7,941 nonpsychiatric controls, whose gestations and births were monitored prospectively with standard research protocols as part of the National Collaborative Perinatal Project. Adult psychiatric morbidity was ascertained via a longitudinal treatment data base indexing regional public health service utilization, and diagnoses were made by review of all pertinent medical records according to DSM-IV criteria. We found that the odds of schizophrenia increased linearly with increasing number of hypoxia-associated OCs and that this effect was specific to cases with an early age at onset/first treatment contact. There were no relationships between schizophrenia and birth weight or other (prenatal/nonhypoxic) OCs. Siblings of patients with schizophrenia were no more likely to have suffered hypoxia-associated OCs than were nonpsychiatric cohort controls. Because the majority of individuals exposed to fetal hypoxia did not develop schizophrenia, such factors likely are incapable of causing schizophrenia on their own. Together, these findings suggest that hypoxia acts additively or interactively with genetic factors in influencing liability to schizophrenia. We propose a model in which the neurotoxic effects of fetal hypoxia may lead to an earlier onset of psychosis because of premature pruning of cortical synapses.

Adult↗
PubMed2000

Childhood neuromotor dysfunction in schizophrenia patients and their unaffected siblings: a prospective cohort study.

Neuromotor dysfunction is a consistent finding in high-risk and archival studies of schizophrenia, but the sources of this dysfunction and its role in the developmental course of the disorder remain poorly understood. This study examined childhood motor predictors of adult psychiatric outcome in a birth cohort sample (72 patients with schizophrenia or schizoaffective disorder, 63 unaffected siblings, and 7,941 nonpsychiatric controls), evaluated prospectively with neurologic examinations at 8 months, 4 years, and 7 years of age. Deviance on motor coordination measures at 7 years was associated with both adult schizophrenia and unaffected sibling status, suggesting that a cofamilial (and perhaps genetic) factor underlies motor coordination deficits in schizophrenia. Unusual movements at ages 4 and 7 predicted adult schizophrenia but not unaffected sibling status, indicating that these deficits may be specific to those who will develop the clinical phenotype. None of the motor precursors were confined to patients with an early age at first treatment contact. Fetal hypoxia predicted unusual movements at 4 but not 7 years among the preschizophrenia subjects, suggesting neurodevelopmental dependence of its functional effects. Neither prenatal complications nor birth weight were associated with motor dysfunction in preschizophrenia subjects or their unaffected siblings at any age. Finally, preschizophrenia children did not show the expected developmental decline in unusual movements, perhaps reflecting aberrant functional maturation of cortical-subcortical pathways.

Adult↗
PubMed2000

Childhood cognitive functioning in schizophrenia patients and their unaffected siblings: a prospective cohort study.

While it is known that children of schizophrenia parents perform more poorly on tests of cognitive functioning than children of normal parents, less certain is the degree to which such deficits predict schizophrenia outcome, whether cognitive functioning deteriorates during childhood in preschizophrenia individuals, and whether nongenetic etiologic factors (such as obstetric complications) contribute to these deficits. In the present study, 72 patients with schizophrenia or schizoaffective disorder, 63 of their siblings not diagnosed with schizophrenia, and 7,941 controls with no diagnosis were ascertained from a birth cohort whose members had been evaluated with standardized tests of cognitive functioning at 4 and 7 years of age. Adult psychiatric morbidity was ascertained via a longitudinal treatment data base indexing regional public health service utilization, and diagnoses were made by review of all pertinent medical records according to DSM-IV criteria. Both the patients with schizophrenia and their unaffected siblings performed significantly worse than the nonpsychiatric controls (but did not differ from each other) on verbal and nonverbal cognitive tests at 4 and 7 years of age. Preschizophrenia cases and their siblings were increasingly overrepresented across decreasing quartiles of the performance distributions. There was not significant intra-individual decline, and there were no significant relationships between obstetric complications and test performance among the preschizophrenia subjects. These results suggest that during the period from age 4 to age 7 years, premorbid cognitive dysfunction in schizophrenia represents a relatively stable indicator of vulnerability deriving from primarily genetic (and/or shared environmental) etiologic influences.

Adult↗
PubMed2000

A prospective cohort study of childhood behavioral deviance and language abnormalities as predictors of adult schizophrenia.

Language and behavioral deviance in early childhood in preschizophrenia individuals suggests that the pathologic processes predisposing to schizophrenia are present from early in life. However, the etiologic antecedents of such impairments, and the degree to which they predict adult schizophrenia, have not been conclusively demonstrated. To address this, we examined language and behavioral predictors of adult psychiatric outcome in a population cohort (72 individuals with schizophrenia or schizoaffective disorder, 63 of their unaffected siblings, and 7,941 with no diagnosis) evaluated prospectively with behavioral examinations and a speech and language evaluation at 8 months, 4 years, and 7 years of age. Psychiatric outcome was ascertained via adult treatment contacts, and diagnoses were made by chart review according to DSM-IV criteria. Social maladjustment at age 7 was found to predict adult schizophrenia, and focal deviant behaviors (e.g., echolalia, meaningless laughter) at ages 4 and 7 were significantly associated with both schizophrenia and sibling status. Unintelligible speech at age 7 was a highly significant predictor of adult schizophrenia (odds ratio = 12.7), and poor expressive language ability predicted both schizophrenia and unaffected sibling outcome. Early behavioral and language dysfunction did not differentially characterize preschizophrenia subjects with a history of fetal hypoxia or an early age of first treatment contact. Given that unaffected siblings show similar signs of deviance, such problems may indicate genotypic susceptibility to the disorder, or shared environmental influences, or both.

Adult↗
PubMed1999

A prospective cohort study of neurodevelopmental processes in the genesis and epigenesis of schizophrenia.

A number of lines of evidence converge in implicating neurodevelopmental processes in the etiology and epigenesis of schizophrenia. In this study we used a prospective, longitudinal design to examine whether adverse obstetric experiences predict schizophrenia and whether there is a deviant functional-developmental trajectory during the first 7 years of life among individuals who manifest schizophrenia as adults. The 9,236 members of the Philadelphia cohort of the National Collaborative Perinatal Project were screened for mental health service utilization in adulthood, and chart reviews were performed to establish diagnoses according to DSM-IV criteria. The risk for schizophrenia increased linearly with the number of hypoxia-associated obstetric complications but was unrelated to maternal infection during pregnancy or fetal growth retardation. Preschizophrenic cases (and their unaffected siblings who were also cohort members) manifested cognitive impairment, abnormal involuntary movements and coordination deficits, and poor social adjustment during childhood. There was no evidence of intraindividual decline in any domain, but preschizophrenic cases did show deviance on an increasing number of functional indicators with age. Together, these findings suggest that both genetic and obstetric factors participate in creating a neural diathesis to schizophrenia, the phenotypic expressions of which are age dependent, probably reflecting the maturational status of a number of interconnected brain systems.

Adult↗
PubMed1998

Evaluating the quality of clinical guidelines. Linking decisions to medical evidence.

The validity and applicability of recommendations in clinical medicine are dependent on the design of studies upon which recommendations are based. Large prospective randomized controlled trials (RCT) generally provide the most reliable data to help guide our treatment decisions. However, analysis of decision-making in the field of hematologic malignancies indicates that only 24% of decisions can be based on randomized controlled trials. This lack of high-quality data to support many decisions in the treatment of malignant disorders underscores the need to evaluate the evidence that forms the backbone of guidelines themselves. As physicians are encouraged to conform to clinical guidelines, it is important that information be made available regarding the quality of data upon which these guidelines are based. We propose the development and use of a guideline quality score based on the quality of evidence supporting each decision in a guideline. By linking the quality of evidence with specific recommendations, physicians will be in a better position to understand the strengths and weaknesses of practice guidelines. This linkage will also help physicians to streamline their efforts to obtain a new line of evidence when an existing one is not satisfactory.

Decision Making↗
PubMed1996

Safety and efficacy of purified factor IX concentrate and antifibrinolytic agents for dental extractions in hemophilia B.

This study evaluated the safety and efficacy of combined treatment with epsilon-aminocaproic acid or tranexamic acid and monoclonal antibody purified factor IX (MAb factor IX) for prophylaxis against bleeding in eight hemophilia B patients undergoing nine dental extraction procedures. All patients achieved excellent hemostasis without clinical evidence of thrombosis. There were no significant changes in hemoglobin or hematocrit or in markers of hemostatic system activation (prothrombin fragment F1+2, fibrinopeptide A, and fragment B beta 15-42) after surgery. Thus, a highly purified factor IX concentrate and antifibrinolytic therapy can be effectively and safely combined in hemophilia B patients undergoing dental extractions.

Adult↗
PubMed1996

The Duffy antigen receptor for chemokines: structural analysis and expression in the brain.

The Duffy antigen receptor for chemokines (DARC) is expressed in human erythrocytes and on endothelial cells lining postcapillary venules in kidney and spleen. DARC is a promiscuous chemokine receptor and a binding protein for the malarial parasite Plasmodium vivax. The expression of DARC by subsets of endothelial cells and neurons in discrete anatomic sites in the brain suggests that this enigmatic receptor may have multiple roles in normal and pathological physiology. Conservation of this promiscuous chemokine binding function is evident from the similarity in nucleotide sequence of DARC homologues from multiple species, as well as the high-affinity binding of human chemokines to murine and avian erythrocytes. Analysis of the functional domains of DARC using chimeric receptors and and monoclonal antibodies to multiple extracellular domains localized chemokine binding to structures in the amino terminal extracellular domain (E1). Scatchard analysis demonstrated that a chimeric DARC receptor, composed of the E1 domain of DARC and the predicted hydrophobic helices and loops of interleukin-8RB (IL-8RB), bound IL-8, and MGSA with KD values almost identical to the wild type receptors and bound a repertoire of C-X-C and C-C chemokines characteristic of DARC. Although numerous reports have demonstrated that chemokines such as IL-8 are expressed in the brain, presumably by glial cells, little insight into the nature of their role in normal or pathological physiology in the nervous system has developed because the target cells that express the corresponding receptors have not yet been identified. Northern blotting experiments suggest that mRNA encoding DARC are expressed in the central nervous system, however, interpretation of this is unclear because of the ubiquitous expression of DARC lining postcapillary venules. This study provides direct evidence to localize expression of DARC in the central nervous system. Immunohistochemical examination of human archival sections of the brain with monoclonal antibodies specific for DARC localize expression of DARC to cell bodies and processes of Purkinjie cells in the cerebellum. The immunohistochemical findings were supported by analysis of chemokine binding and radioligand crosslinking with membranes made from various brain fractions. The hierarchical expression of DARC in neurons in the cerebellum suggest that chemokines may play an important role in the modulation of neuronal activity by glial cells.

Animals↗
PubMed1995

Phase II trial of 5-fluorouracil, folinic acid, and N,N1,N11-triethylenethiophosphoramide (thiotepa) in patients with advanced breast cancer.

A total of 35 women with advanced, metastatic breast cancer were treated with combination chemotherapy consisting of folinic acid 500 mg/m2 over 2 hours administered with 600 mg/m2 of 5FU at the midpoint of the folinic acid infusion weekly for 6 weeks, plus 60 mg/m2 of thiotepa on day 1 and day 28. The cycle was repeated every 8 weeks. Patients were evaluated for toxicity weekly. Response was evaluated at the end of each 8-week cycle. The median age was 55 years (range: 34-67). Prior to this study 30 patients had received chemotherapy; 13 had 1 regimen; 17 had 2 or more regimens; 8 had 5FU treatment. The overall response rate was 40% (1 complete and 13 partial); median duration of response was 4 months. Four of 8 patients with prior 5FU responded. Hematologic toxicity was significant; nadir WBC count: < 1,000/mm3 (10 patients); 1,000-1,999/mm (13 patients); nadir platelet count: < 20,000/mm3 (8 patients): 20,000-49,000/mm3 (8 patients); 50,000-99,000/mm3 (10 patients). We conclude that the combination of thiotepa, 5FU, and leucovorin had significant myelotoxicity and do not recommend its routine use in the treatment of metastatic breast cancer.

Adult↗
PubMed1993

High-dose chlorambucil and dexamethasone for relapsed non-Hodgkin's lymphomas.

Twenty patients with relapsed or refractory non-Hodgkin's lymphoma were treated with high-dose chlorambucil (14 mg/m2 every 6 hours for 6 doses) and dexamethasone (40 mg/day for 5 days). There was a 45% response rate with 17% complete responses. The median duration of complete response was 7 months. The regimen was well tolerated and had minimal toxicity.

Adult↗
PubMed1992

Residual mediastinal mass after treatment of Hodgkin's disease: a decision analysis.

A residual mediastinal mass after completion of initial treatment for Hodgkin's disease is a frequent clinical problem. Investigators have suggested three possible approaches to this important problem: 1) observation, 2) additional diagnostic tests with subsequent action based upon test results, or 3) immediate treatment for high-risk patients. The method of decision analysis was applied to determine the optimal management for residual mediastinal abnormalities following treatment of Hodgkin's disease with combined modalities of MOPP chemotherapy and radiation therapy. The three parameters of the importance for making the best decision were: 1) the probability that the mass is truly active disease, 2) the salvage success rate using MOPP or ABVD treatment and 3) the specificity of the gallium scan. The analysis favored the gallium imaging strategy as an initial management choice when the probability was greater than 3% that the residual mass represented active disease and the specificity of gallium imaging was greater than 56%. This strategy proved to be the most cost effective, as well. Additional chemotherapy was favored only when there was a greater than 99% probability that the mass represented active disease. A nomogram has been constructed combining all three parameters of importance for graphically determining the best decision.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Occurrence of high-grade T-cell lymphoma in a patient with Philadelphia chromosome-negative chronic myelogenous leukemia with breakpoint cluster region rearrangement: case report and review of the literature.

In this report, we describe a patient with Philadelphia chromosome-negative chronic myelogenous leukemia (CML) with breakpoint cluster region gene rearrangement who developed T-cell lymphoblastic lymphoma. The occurrence of T-cell lymphoblastic lymphoma coincided with the appearance in the bone marrow of the cytogenetic abnormality, trisomy 22q11.2----22qter. This is the first report of high-grade T-cell lymphoma in a patient with documented CML.

Adult↗
PubMed1991

GM-CSF in the treatment of Felty syndrome.

Many therapeutic agents have been tried with variable success in the treatment of Felty neutropenia, but the reports are anecdotal. We now describe the second trial of recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF), in a splenectomized, infected patient with Felty syndrome.

Felty Syndrome↗
PubMed1991

A new algorithm for the diagnosis of polycythemia.

A new algorithm for the diagnostic evaluation of erythrocytosis is presented. This algorithm is based on principles of decision-making analysis and on the pathophysiology of erythrocytosis. The initial task is to identify smokers, because of the high probability that they have "smoker's" polycythemia. The current diagnostic criteria for polycythemia vera may be insufficient when the probability of disease is low but may be too rigorous when the probability of disease is high.

Algorithms↗