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Biomedical subjects

J Kaufman

Publications and source records attributed to J Kaufman.

At least 55 records · Page 3Linked to original sources

Parent-child bonding and family functioning in depressed children and children at high risk and low risk for future depression.

OBJECTIVE: To evaluate parent-child bonding and familial functioning in depressed children, children at high risk for depression, and low-risk controls. METHOD: Diagnoses of children and their relatives were obtained via structured interviews with all available informants. Depressed children (n = 54) received a diagnosis of current major depressive disorder (MDD). The high-risk children (n = 21) had no lifetime diagnoses of mood disorders, but at least one first-degree relative with a lifetime history of depression. The low-risk controls (n = 23) had no lifetime psychiatric disorders and no first-degree relative with a lifetime history of mood disorders. Parent-child bonding was evaluated with the child's report on the Parental Bonding Instrument (PBI). Familial functioning was evaluated with each parent answering the Family Assessment Device (FAD). RESULTS: Significant differences were found between the MDD and low-risk children on most parameters of the PBI and FAD. The children with MDD reported significantly elevated maternal overprotection, and their fathers scored significantly lower on the FAD scales of Behavioral Control and General Functioning, compared with the high-risk children. Mothers of high-risk children had significantly lower scores on the Roles and Affective Involvement dimensions of the FAD compared with mothers of low-risk children. Current maternal depression had a deleterious effect on the child's perception of maternal protection and paternal care, mother's report on all FAD scales, and father's report on most FAD scales, whether interacting with the child's depression or existing even if the child was not depressed. CONCLUSION: Maternal depression and its interaction with the child's depression appear to have negative consequences for parent-child bonding and family functioning.

Adolescent↗

Pharmacotherapy of early-onset depression. Update and new directions.

Although an increased recognition of depressive disorders in youth represents a positive conceptual change over the past decades, there still is a very limited amount of research on useful treatment interventions. The paucity of data is particularly keen for the use of psychotropic drugs. For example, by applying the criteria suggested by the International Psychopharmacology Algorithm Project, there barely are enough first-grade ("Level A," meaning at least two RCTs) data supporting the short-term efficacy of antidepressants (the SSRIs) in the treatment of juvenile depression. And yet, limited data have not translated into limited use in routine clinical practice. In fact, the use of antidepressant medications has increased exponentially over the last decade, a change that is especially conspicuous for individuals less than 18 years of age. The perceived safety of the SSRIs and other novel antidepressants is partly at the root of their increased popularity. Data regarding their safety are likewise quite limited, however, and essentially are nonexistent for longer-term use. Based on the reviewed data, a medication algorithm for the treatment of early-onset depression can be suggested (Fig. 1). The algorithm underscores the need for adequate evaluation and diagnostic assessment, with particular attention to comorbid conditions (such as a bipolar diathesis) that may dictate alternative treatment strategies. In general, psychotherapy is the initial approach to juvenile MDD, with medication use reserved for more severe cases or those not responding to psychotherapy alone. Given that only two types of psychotherapy and two SSRIs have adequate controlled short-term efficacy data, all but the initial steps must be undertaken guided by clinical judgment and an individualized risk-benefit analysis. An algorithm such as this one, based on the very limited efficacy and safety data available, may be viewed as setting priorities for a comprehensive research agenda, more than dictating rigid treatment guidelines. In closing, it can be suggested that future research on the pharmacotherapy of early-onset depressive disorder pay particular attention to the following three aspects: 1. Too many drugs, too few data: Rapid advances in drug development have led to a plethora of available antidepressant agents. It is clear that there are many more agents available than can be adequately studied at present. Because many such agents are mechanistically similar, if not identical, it may be wise to focus research efforts on truly novel agents, particularly those (such as the CRH receptor antagonists, or those affecting neurosteroidogenesis) whose action is based on preclinical and clinical pathophysiologic disease paradigms. 2. Longitudinal follow-up and maintenance studies: Essentially all reviewed treatment studies have been short-term trials. There is a marked paucity of longer-term follow-up data, or of naturalistic and "real-world" effectiveness studies. For example, one of the few studies addressing maintenance pharmacotherapy for early-onset depression has demonstrated surprisingly high recurrence rates, even for those subjects actively on maintenance medication. 3. Long-term safety: Clinicians and parents alike often face difficult decisions regarding the long-term exposure of antidepressant drugs on the developing brain. Although no definitive long-term safety data are likely to become available anytime soon, real risks, such as suicide, and potential sequelae of long-term exposure to the underlying illness itself need all to be part of any decision-making process. Preclinical studies have shown that brain-derived neurotrophic factor (BDNF) levels can be upregulated by antidepressants, and low BDNF factors have been associated with atrophic brain changes in recurrent forms of adult MDD. Although these observations require specific application to juvenile forms of the disorder, they raise the exciting prospect that the natural course of the illne

Adolescent↗

A case-crossover analysis of fine particulate matter air pollution and out-of-hospital sudden cardiac arrest.

Numerous recent epidemiologic studies report increases in the daily incidence of cardiovascular disease mortality and morbidity related to increases in daily levels of fine particulate matter (PM)* air pollution. This study sought to evaluate the possible association between the occurrence of out-of-hospital sudden cardiac arrest (SCA) and daily PM levels in the Seattle metropolitan area. The underlying hypothesis was that PM exposure may act as a cardiovascular trigger for SCA. A case-crossover study was conducted among 362 SCA cases identified by paramedics from October 1988 through June 1994. Cases were King County WA residents who were married, aged 25 to 74 years at the time of their SCA, with no prior history of clinically recognized heart disease or other life-threatening comorbid conditions. Daily averages of regional PM monitoring data for nephelometry measures of PM (reported in units of bsp, referred to as coefficient of light scattering) and PM10 (particulate matter 10 microm or smaller in aerodynamic diameter) from three monitoring sites were used as indicators of exposure. In the case-crossover analysis, PM levels during index times of cases within the five days preceding an SCA were compared with PM levels at referent days, defined as the same days of the week during the month of SCA occurrence. Lag periods for index days of 0 to 5 days were investigated. The estimated relative risk (RR) at a lag of 1 day for an interquartile range (IQR) change in nephelometry (0.51 bsp) was 0.893 (95% confidence interval [CI] 0.779-1.024). Varying the lag period had only minimal change on the observed association. The estimated relative risk at a lag of 1 day for an IQR change of PM10 (19.3 microg/m3) was 0.868 (95% CI 0.744-1.012). There was no evidence of confounding by ambient daily exposures to carbon monoxide or sulfur dioxide. Analysis of effect modification by individual-level variables, including age, cigarette smoke exposure, physical activity, and other risk or protective factors for cardiovascular disease did not reveal any susceptible subgroups. The null results of this study may be due to several factors; these include: the highly selected nature of this SCA case series; the fact that cases were free of prior clinically recognized heart disease or major life-threatening comorbidity; and the possibility that PM exposures at the relatively low levels seen in the Seattle metropolitan area do not trigger cardiovascular toxic mechanisms that culminate in SCA.

Adult↗

The chicken B locus is a minimal essential major histocompatibility complex.

Here we report the sequence of the region that determines rapid allograft rejection in chickens, the chicken major histocompatibility complex (MHC). This 92-kilobase region of the B locus contains only 19 genes, making the chicken MHC roughly 20-fold smaller than the human MHC. Virtually all the genes have counterparts in the human MHC, defining a minimal essential set of MHC genes conserved over 200 million years of divergence between birds and mammals. They are organized differently, with the class III region genes located outside the class II and class I region genes. The absence of proteasome genes is unexpected and might explain unusual peptide-binding specificities of chicken class I molecules. The presence of putative natural killer receptor gene(s) is unprecedented and might explain the importance of the B locus in the response to the herpes virus responsible for Marek's diseases. The small size and simplicity of the chicken MHC allows co-evolution of genes as haplotypes over considerable periods of time, and makes it possible to study the striking MHC-determined pathogen-specific disease resistance at the molecular level.

Amino Acid Sequence↗

Biophysical and functional characterization of full-length, recombinant human tissue inhibitor of metalloproteinases-2 (TIMP-2) produced in Escherichia coli. Comparison of wild type and amino-terminal alanine appended variant with implications for the mechanism of TIMP functions.

Matrix metalloproteinases (MMPs) function in the remodeling of the extracellular matrix that is integral for many normal and pathological processes. The tissue inhibitor of metalloproteinases family, including tissue inhibitor of metalloproteinases-2 (TIMP-2), regulates the activity of these multifunctional metalloproteinases. TIMP family members are proteinase inhibitors that contain six conserved disulfide bonds, one involving an amino-terminal cysteine residue that is critical for MMP inhibitor activity. TIMP-2 has been expressed in Escherichia coli, folded from insoluble protein, and functionally characterized. The wild type protein inhibited gelatinase A (MMP-2), whereas a variant with an alanine appended to the amino terminus (Ala+TIMP-2) was inactive. Removal of amino-terminal alanine by exopeptidase digestion restored protease inhibitor activity. This confirms the mechanistic importance of the amino-terminal amino group in the metalloproteinase inhibitory activity, as originally suggested from the x-ray structure of a complex of MMP-3 with TIMP-1 and a complex of TIMP-2 with MT-1-MMP. The Ala+TIMP-2 variant exhibited conformational, pro-MMP-2 complex formation and fibroblast growth modulating properties of the wild type protein. These findings demonstrate that Ala+TIMP-2 is an excellent biochemical tool for examining the specific role of MMP inhibition in the multiple functions ascribed to TIMPs.

Escherichia coli↗

The crystal structure of the SIV gp41 ectodomain at 1.47 A resolution.

Cell membrane fusion by human (HIV) and simian (SIV) immunodeficiency viruses is mediated by the envelope glycoproteins gp120 and gp41. Although the precise mechanism of the fusion process is unknown, the ectodomain of gp41 is thought to undergo dramatic rearrangement from its prefusogenic state. To elucidate this process further, the crystal structure of the SIV gp41 ectodomain (residues 27-149) was determined at 1.47 A resolution and is reported herein. It is the most accurate and complete structure of a retroviral gp41 ectodomain determined to date. The rod-like trimeric structure of SIV gp41 comprises three parallel N-terminal alpha-helices assembled as a coiled coil in the center with three antiparallel C-terminal alpha-helices packed on the outside connected by highly flexible loops. Portions of the loops in all three monomers are crystallographically disordered and could not be accurately modeled. The core of the structure is similar (but not identical) to those of smaller HIV/SIV gp41 segments previously determined by X-ray crystallography with root mean square deviations in main chain atoms of less than 1.0 A. The crystal structure differs more substantially from the reported NMR solution structure of the identical SIV construct. The mechanisms of viral fusion and the inhibition by peptides are discussed in the context of the three-dimensional structure.

Amino Acid Sequence↗

Renal hemorrhage in polyarteritis nodosa: diagnosis and management.

We report a patient with biopsy-proven polyarteritis nodosa with massive hemorrhage from presumed interlobar artery rupture. The use of interventional radiology techniques such as embolization are discussed in the acute management of such patients. Embolization by interventional radiology should be considered a useful alternative to surgery in these patients. The utility of angiography as a diagnostic and therapeutic tool is demonstrated in this case.

Aneurysm, Ruptured↗

The distribution and mortality impact of chronic energy deficiency among adult Nigerian men and women.

OBJECTIVE: To determine the prevalence of chronic energy deficiency (CED) and associated mortality risk in a cohort of adult Nigerians followed from 1992 to 1997. RESEARCH METHODS AND PROCEDURES: The data for this investigation were derived from an international collaborative study on chronic diseases in populations of the African diaspora. Body mass index (BMI) was used to define three grades of CED in 4061 men and women aged 25 years and older: Grade I (mild CED) as BMI 17.5-18.4, Grade II (moderate CED) as BMI 16.0-17.4, and Grade III (severe CED) as BMI < 16.0 and BMI > or = 18.5 was considered normal. The odds of mortality associated with differing grades of CED was estimated with logistic regression analysis. RESULTS: The prevalence of CED (BMI < 18.5) increased from 14.3% in 1992 to 19.6% in 1997, both genders combined. The prevalence of CED was similar for both sexes in 1992 (14%) but increased to 22.4% in men and 17.4% in women by 1997. The prevalence of CED was 8.5%, 7.6 and 3.4 for Grades I, II and III, respectively. Two hundred and seven deaths occurred during the follow-up period. The mortality rate for the 5.5 y of follow-up was 5.1% (207/4061). The odds ratios (95% CIs) for all cause mortality were 1.4 (0.5, 3.8), 2.4 (1.2, 4.9) and 2.5 (1.0, 6.2), respectively, for CED grades I, II and III adjusting for age and sex. CONCLUSION: Under nutrition is an increasing problem in Nigerian men and women. The economic reforms (structural adjustment program (SAP)) introduced in 1986 in combination with the continued economic woes brought on by political instability, corruption and nepotism have been advanced by several investigators as the main factors in the growing problem of inadequate calorie intake. Intervention strategies both at the government and private sectors are urgently needed to increase food availability.

Adult↗

Monomer-trimer equilibrium of the ectodomain of SIV gp41: insight into the mechanism of peptide inhibition of HIV infection.

The monomer-trimer equilibrium of the ectodomain of SIV gp41 (residues 27-149, e-gp41) has been characterized by analytical ultracentrifugation, circular dichroism (CD), and NMR spectroscopy. Based on analytical ultracentrifugation experiments performed at different rotor speeds and protein concentrations, the equilibrium association constant for the SIV e-gp41 trimer is 3.1 x 10(11) M(-2). The presence of intermolecular nuclear Overhauser effects in a mixture of 12C and 13C-labeled e-gp41 prepared under nondenaturing conditions unambiguously demonstrates that there is a dynamic equilibrium between the monomer and trimer. The CD spectra taken as a function of SIV e-gp41 concentration suggest that the helical content of the monomeric state does not change significantly relative to that of the trimeric state. The relevance of the monomer-trimer equilibrium is discussed with respect to gp41 function and the inhibitory properties of gp41 peptides.

Anti-HIV Agents↗

Gene organisation determines evolution of function in the chicken MHC.

Some years ago, we used our data for class I genes, proteins and peptide-binding specificities to develop the hypothesis that the chicken B-F/B-L region represents a "minimal essential MHC". In this view, the B locus contains the classical (highly expressed and polymorphic) class I alpha and class II beta multigene families, which are reduced to one or two members, with many other genes moved away or deleted from the chicken genome altogether. We found that a single dominantly expressed class I gene determines the immune response to certain infectious pathogens, due to peptide-binding specificity and cell-surface expression level. This stands in stark contrast to well-studied mammals like humans and mice, in which every haplotype is more-or-less responsive to every pathogen and vaccine, presumably due to the multigene family of MHC molecules present. In order to approach the basis for a single dominantly expressed class I molecule, we have sequenced a portion of the B complex and examined the location and polymorphism of the class I (B-F) alpha, TAP and class II (B-L) beta genes. The region is remarkably compact and simple, with many of the genes expected from the MHC of mammals absent, including LMP, class II alpha and DO genes as well as most class III region genes. However, unexpected genes were present, including tapasin and putative natural killer receptor genes. The region is also organised differently from mammals, with the TAPs in between the class I genes, the tapasin gene in between the class II (B-L) beta genes, and the C4 gene outside of the class I alpha and class II beta genes. The close proximity of TAP and class I alpha genes leads to the possibility of co-evolution, which can drive the use of a single dominantly expressed class I molecule with peptide-binding specificity like the TAP molecule. There is also a single dominantly expressed class II beta gene, but the reason for this is not yet clear. Finally, the presence of the C4 gene outside of the classical class I alpha and class II beta genes suggests the possibility that this organisation was ancestral, although a number of models of organisation and evolution are still possible, given the presence of the Rfp-Y region with non-classical class I alpha and class II beta genes as well as the presence of multigene families of B-G and rRNA genes.

Animals↗

A study of field-based methods for diagnosing reproductive tract infections in rural Yunnan Province, China.

Reproductive tract infections are a significant cause of poor health among rural Chinese women. This study assesses the accuracy of simple, field-based methods of diagnosing five reproductive tract infections (trichomonas, candida, bacterial vaginosis, gonorrhea, and chlamydia) in two rural Chinese counties, using "gold standard" laboratory diagnosis as the reference. Self-reported symptoms and clinical examination proved inadequate for making accurate diagnoses, because many infected women show no symptoms or are infected with two or more conditions. The use of simple tests such as KOH staining, wet mount, Gram's stain, and pH of discharge greatly improved diagnostic accuracy, especially for candida and trichomonas, the two most common infections. Promoting the use of such diagnostic approaches by rural Chinese medical and family planning health providers would reduce the prevalence and severity of these preventable and easily treated infections.

Adolescent↗

Use of streamline chelating for capture and purification of poly-His-tagged recombinant proteins.

Expression of recombinant proteins with poly-histidine tags enables their convenient capture and purification using immobilized metal affinity chromatography (IMAC). The 6 x His-tagged protein binds to a chelating resin charged with metal ions such as Ni2+, Cu2+ or Zn2+, and can therefore be separated from proteins which have lower, or no, affinity for the resin. Two recombinant proteins, a malaria transmission-blocking vaccine candidate secreted extracellularly by S. cerevisiae and a modified diphtheria toxin produced intracellularly by E. coli, were expressed with 6 x His tags and could therefore be purified using IMAC. In an effort to further simplify the initial capture of these proteins, an expanded bed adsorption technique using a chelating resin (Streamline Chelating) was introduced. It was possible to capture the intracellular diphtheria protein from E. coli directly after cell lysis, without prior centrifugation or filtration. The extracellular malaria vaccine candidate was also directly captured from a high cell density yeast culture. Detailed information on the experimental work performed, and the capture processes developed, is provided.

Adsorption↗

Serotonergic functioning in depressed abused children: clinical and familial correlates.

BACKGROUND: The goal of this study was to examine serotonergic functioning and concomitant clinical and familial correlates in depressed abused children. METHODS: L-5-Hydroxytryptophan (L-5-HTP) (0.8 mg/kg) was administered intravenously to 10 depressed abused (MDD-AB), 10 depressed nonabused (MDD-NA), and 10 normal control nonabused (NC-NA) children. The children in the two nonabused cohorts represent a small matched subset of children from a larger interlocking study of the psychobiology of depression. Blood samples for prolactin and cortisol were collected from 30 min before to 2.5 hours after L-5-HTP infusion. RESULTS: The MDD-AB children secreted significantly more prolactin post-L-5-HTP than the children in the other two groups. There were no differences in baseline prolactin or any of the cortisol measures. Total prolactin post-L-5-HTP was significantly correlated with clinical ratings of aggressive behavior (rho = .48). In addition, children with a family history positive for suicide attempt (MDD-AB: n = 7; MDD-NA: n = 5; NC-NA: n = 2) secreted significantly more prolactin post-L-5-HTP than children with no family history of suicide. CONCLUSIONS: Dysregulation in the serotonergic system in abused children appears to be related to both familial and experiential factors.

5-Hydroxytryptophan↗

Three-dimensional solution structure of the 44 kDa ectodomain of SIV gp41.

The solution structure of the ectodomain of simian immunodeficiency virus (SIV) gp41 (e-gp41), consisting of residues 27-149, has been determined by multidimensional heteronuclear NMR spectroscopy. SIV e-gp41 is a symmetric 44 kDa trimer with each subunit consisting of antiparallel N-terminal (residues 30-80) and C-terminal (residues 107-147) helices connected by a 26 residue loop (residues 81-106). The N-terminal helices of each subunit form a parallel coiled-coil structure in the interior of the complex which is surrounded by the C-terminal helices located on the exterior of the complex. The loop region is ordered and displays numerous intermolecular and non-sequential intramolecular contacts. The helical core of SIV e-gp41 is similar to recent X-ray structures of truncated constructs of the helical core of HIV-1 e-gp41. The present structure establishes unambiguously the connectivity of the N- and C-terminal helices in the trimer, and characterizes the conformation of the intervening loop, which has been implicated by mutagenesis and antibody epitope mapping to play a key role in gp120 association. In conjunction with previous studies, the solution structure of the SIV e-gp41 ectodomain provides insight into the binding site of gp120 and the mechanism of cell fusion. The present structure of SIV e-gp41 represents one of the largest protein structures determined by NMR to date.

Amino Acid Sequence↗