Striatal size and relative glucose metabolic rate in schizotypal personality disorder and schizophrenia

BACKGROUND

Schizotypal personality disorder (SPD) shares social deficits and cognitive impairment with schizophrenia, but is not typically characterized by frank psychosis. Because striatal size and functional activity have both been shown to be associated with psychotic symptoms, we carried out the first study of SPD to assess the caudate and putamen for comparison with findings in schizophrenia.

METHODS

Patients with SPD (n = 16), schizophrenic patients (n = 42), and age- and sex-matched normal control subjects (n = 47) were assessed with magnetic resonance imaging. All of the patients with SPD and subsamples of the schizophrenic patients (n = 27) and control subjects (n = 32) were also assessed with positron emission tomography using fluorodeoxyglucose F-18.

RESULTS

The relative size of the putamen in controls was significantly larger than in patients with SPD and significantly smaller than in schizophrenic patients, while the relative size of the caudate was similar in all 3 groups. Compared with control values, relative glucose metabolic rate in the ventral putamen was significantly elevated in patients with SPD and reduced in schizophrenic patients. When subsamples of schizophrenic patients (n = 10) and patients with SPD (n = 10) both of whom never received medication were compared, this pattern was more marked, with the highest value for the putamen being found in patients with SPD for the ventral slice and the lowest value for the right dorsal putamen.

CONCLUSIONS

Patients with SPD showed reduced volume and elevated relative glucose metabolic rate of the putamen compared with both schizophrenic patients and controls. These alterations in volume and activity may be related to the sparing of patients with SPD from frank psychosis.

Temporal lobe volume determined by magnetic resonance imaging in schizotypal personality disorder and schizophrenia

The volumes of the whole temporal lobe, the superior temporal gyrus and the corpus callosum were measured on magnetic resonance images from 13 patients with schizotypal personality disorder (SPD), 27 patients with schizophrenia, and 31 age- and sex-matched controls. Temporal lobe structures were traced on consecutive 1.2mm thick SPGR images. Both patient groups had smaller temporal lobes than normal volunteers, a difference that was more marked for the area outside the superior temporal gyrus than for the STG. Correcting for brain volume diminished differences between normal subjects and schizophrenia patients, but the differences between normal subjects and SPD patients remained. Normal volunteers and SPD patients showed significant correlations between the sagittal section area of the posterior portion of the corpus callosum, which carries temporal interhemispheric connections, and the white matter volume of the temporal lobe. While the sample size is modest, taken together, these results suggest that the psychopathological symptoms of SPD may be related to temporal gray matter loss with relatively intact white matter connectivity, while the cognitive and psychotic symptoms of schizophrenia may be related to temporal gray loss combined with disruption of normal patterns of white matter development.

Physostigmine and cognition in schizotypal personality disorder

There is evidence that reduced cholinergic activity may play a role in the pathophysiology of cognitive impairment in the schizophrenia spectrum. We tested the effects of physostigmine, an anticholinesterase inhibitor, on visuospatial working memory as evaluated by the Dot test, and on verbal learning and recall as measured by a serial learning task in patients with schizotypal personality disorder. Physostigmine tended to improve the Dot test, but not serial verbal learning performance in these patients.

Influenza surveillance in England and Wales: October 1999 to May 2000

The period of increased influenza activity in England and Wales in the winter of 1999/2000 was associated with considerable morbidity and mortality and well-publicized pressure on hospital services. The influenza activity coincided with the regular annual increase in respiratory syncytial virus infections and the Christmas and New Year holiday period. Consultation rates with general practitioners for influenza-like illness did not reach 'epidemic' levels but were higher than seen in many winters and comparable with those seen in two out of the previous three winters. In common with those winters, attack rates for influenza-like illness and acute bronchitis were especially high in elderly people among whom complications of acute infection and hospital admissions increased. Excess mortality due to influenza during this period appeared to be substantial but was not as high as seen in the last epidemic (1989/90).

Assessment of blood lactate: practical evaluation of the Biosen 5030 lactate analyzer

PURPOSE

The aim of this study was to assess the validity and reliability of the Biosen 5030 lactate analyzer compared with a YSI 2300 lactate analyzer and a Kodak Ektachem DTII in a practical laboratory study context.

METHODS

To assess validity, 144 triplicate capillarized blood samples, across a range of values, were analyzed using the three analyzers. To assess reliability a further 665 samples were repeat analyzed. Temporal stability was determined by the reanalysis of resting and maximal exercise blood samples, after a period of storage ranging from 7 to 20 h, at room temperature. To measure inter- and intra-investigator reliability, 20 resting samples were taken from three different subjects by different investigators and a coefficient of variation was determined.

RESULTS

There were strong relationships between the Biosen, the YSI (r2 = 0.97), and the Kodak Ektachem (r2 = 0.91). An analysis of Biosen compared with YSI revealed a positive bias of 0.37 mmol x L(-1) (95% limits of agreement, -0.85 to 1.59 mmol x L(-1)). The test-retest reliability correlation was significant (r2 = 0.99, P < 0.05), but a paired t-test revealed a small (0.03 mmol x L(-1), P < 0.05) significant difference. The coefficient of variation from the three investigators across the 20 samples ranged from 1.3 to 3%. Blood lactate concentration in resting blood samples did significantly increase in value (0.2 mmol x L(-1), P < 0.05) after 7-h exposure to the air, whereas there was no change in maximal exercise blood lactate values after 20-h exposure to the air.

CONCLUSIONS

In a practical context, the Biosen 5030 lactate analyzer was comparable to the other analyzers giving fast reliable measures of blood lactate concentrations over the full range of values, which remained stable over extended periods at room temperature.

Effects of amphetamine on visuospatial working memory performance in schizophrenia spectrum personality disorder

Our objective was to determine if amphetamine improves visuospatial working memory, which is impaired in the schizophrenia spectrum and may be modulated by dopamine in prefrontal cortex. To this end, oral amphetamine (30 mg) was administered to 12 patients with schizophrenia spectrum personality disorders and 13 patients with other, nonschizophrenia-related personality disorders. Visuospatial working memory was assessed using the Dot test; a test in which subjects are asked to memorize and reproduce the position of a dot on a sheet of paper. Patients with schizophrenia spectrum personality disorders performed significantly worse than the comparison group in the placebo condition and showed significantly greater improvement after amphetamine, as compared to a nonschizophrenia-related personality disorder comparison group. Patients with greatest impairment at baseline improved most. Amphetamine tended to improve negative symptoms; whereas, positive symptoms remained unchanged. Amphetamine may improve visuospatial working memory in schizophrenia spectrum patients.

Influenza activity in England and Wales: October 1998 to June 1999

Influenza activity in England and Wales in the winter of 1998/1999 reached the highest weekly levels seen since the epidemic of 1989/1990. Activity peaked at Christmas and the New Year, adding to the winter pressures on general practitioner and hospital services. Adults aged 65 years and over consulted with general practitioners at the highest rates. Outbreaks of influenza or flu-like illness occurred in several schools and nursing homes and, in June 1999, on a British cruise ship in the Mediterranean. Deaths from all causes reached a higher peak in week 1 of 1999 than occurred in the peak week of the influenza epidemic of 1989/90.

Association between periodontitis and hyperlipidemia: cause or effect?

BACKGROUND

Epidemiological studies suggest a relationship between periodontitis and coronary artery disease, but the mechanism has not been established. Recent studies in animals indicate that low dose endotoxin, as in a gram-negative infection, can induce hyperlipidemia and myeloid cell hyperactivity. The association between periodontitis, systemic exposure to Porphyromonas gingivalis, lipopolysaccharides (LPS), and hyperlipidemia has not been examined in humans.

METHODS

Sera were obtained from 26 adult periodontitis patients and 25 healthy control (C) subjects selected from patients and staff. Serum antibodies against Porphyromonas gingivalis and its LPS were analyzed by enzyme-linked immunosorbent assay (ELISA) and Western blotting, respectively. Serum triglycerides (TG) and cholesterol (CHOL) were assayed by a commercial laboratory. The associations between AP and blood levels of TG, CHOL, and anti-P. gingivalis whole cells and LPS were examined by logistic regression analysis. Peripheral blood polymorphonuclear leukocytes (PMNs) from 6 healthy fasted donors were incubated with purified TG (0.1 mg/ml) for 2 hours at 37 degrees C, stimulated with 100 ng/ml P. gingivalis LPS, and the release of IL-1beta measured by ELISA.

RESULTS

The presence of periodontitis was significantly associated with age (odds ratio = 3.5, P = 0.04), elevated TG levels (odds ratio = 8.6, P = 0.0009), elevated CHOL levels (odds ratio = 7, P = 0.004), elevated ELISA titer (odds ratio = 35, P = 0.003) and reactivity with P. gingivalis LPS (odds ratio = 41, P = 0.001). PMNs from all 6 healthy patients released modest levels of IL-1beta (10 to 60 pg/ml) when stimulated with 100 ng/ml P. gingivalis LPS. Addition of TG resulted in a significant increase (P <0.05) in IL- 1beta secreted that ranged from 7 to 150% over LPS alone. No IL-1beta was elicited by TG or vehicle alone.

CONCLUSIONS

The results of this study indicate the presence of a significant relationship between periodontitis, hyperlipidemia, and serum antibodies against P. gingivalis LPS that warrants further examination in a larger patient population. Furthermore, these studies indicate that elevated triglycerides are able to modulate IL-1beta production by PMNs stimulated with P. gingivalis LPS.

The relationship between the interleukin-1 periodontal genotype and implant loss. Initial data

BACKGROUND

This study investigated the relationship of the interleukin-1 (IL-1) genotype, smoking status, and the patient's age to the survival of osseointegrated dental implants.

METHODS

Twenty-seven patients with 33 implants that had been lost or who had at least 50% bone loss on radiographs were compared to a group of 38 patients who had experienced no bone or implant loss. All lost implants in a private practice were included in the data, except those that had fractured with no previous bone loss.

RESULTS

Smoking was demonstrated to increase the risk of implant failure by a factor of almost 2.5.

CONCLUSIONS

Statistical testing failed to provide evidence of an increased risk for implant failure for patients who are positive for the IL-1 genotype. There was no apparent relationship between the patient's age at the time of placement and implant loss. This study raises several questions concerning the etiology of implant loss and the comparative biology of tissues surrounding implants when compared to those surrounding natural teeth.

d,l-fenfluramine response in impulsive personality disorder assessed with [18F]fluorodeoxyglucose positron emission tomography

Reduced serotonergic activity has been associated with impulsive aggression in personality disordered patients in metabolite and pharmacologic challenge studies. This study used positron emission tomography to explore whether reduced serotonergic function occurs in critical brain regions such as orbital frontal and cingulate cortex that, may play a role in modulating aggression. Six impulsive-aggressive patients and five healthy volunteers were evaluated for changes in regional glucose metabolism after administration of the serotonergic releasing agent d,l-fenfluramine (60 mg, p.o.) or placebo. Volunteers demonstrated increases in orbital frontal and adjacent ventral medial frontal cortex, cingulate, and inferior parietal cortex, whereas impulsive-aggressive patients showed no significant increases in glucose metabolism after fenfluramine in any region. Compared with volunteers, patients showed significantly blunted metabolic responses in orbital frontal, adjacent ventral medial and cingulate cortex, but not in inferior parietal lobe. These results are consistent with reduced serotonergic modulation of orbital frontal, ventral medial frontal, and cingulate cortex in patients with impulsive-aggressive personality disorders.

Effectiveness of a sonic toothbrush in maintenance of dental implants. A prospective study

This study assessed the efficacy of a sonic and a manual toothbrush in reducing plaque and gingivitis around dental implants. Subjects were randomly assigned to either sonic (n = 16) or manual (n = 15) study groups. Groups were balanced according to baseline levels of plaque and gingivitis. The plaque (PI), gingival (GI), and bleeding (BI) indices as well as probing depths were determined at baseline, and at 4, 8, 12, and 24 week follow-up visits. Mean scores per person were calculated for each clinical parameter. Oral hygiene habits, compliance and acceptance were also evaluated over the study period. Within group comparisons from baseline throughout the study, as well as between group comparisons (i.e., sonic versus manual), were determined. Overall, plaque, gingival, and bleeding indices in both groups were lower at each follow-up visit when compared to the baseline. Within group comparisons demonstrated that both the sonic toothbrush subjects and the manual toothbrush subjects had significantly lower PI, GI, and BI scores at each post-baseline visit (4, 8, 12, and 24 weeks) than at baseline (p<0.005). In addition, the sonic toothbrush subjects also had significantly lower probing depths at each post-baseline visit than at baseline (p < 0.005). Between group comparisons demonstrated that the sonic toothbrush subjects over time had significantly lower PI and BI scores around dental implants than the manual toothbrush subjects (Repeated measures MANOVA; PI, p = 0.01; BI, p = 0.017). The sonic toothbrush subjects had lower GI scores and reduced probing depths over time when compared to manual toothbrush subjects but these scores were not statistically significant (GI; probing depth, p > 0.05). No implant problems (e.g., loose screws) were attributable to the sonic toothbrush. Relevant to oral hygiene habits, subjects in both groups demonstrated a high level of compliance with their assigned toothbrush. Overall, the results of this study demonstrated that sonic toothbrushing significantly reduced plaque, gingival inflammation and bleeding, and probing pocket depths around implants over the 6-month trial period. It is concluded that sonic brushing is an effective means of dental implant maintenance.

Tetracycline fibers plus scaling and root planing versus scaling and root planing alone: similar results after 5 years

This paper presents 5-year data pertaining to a subgroup of patients from a previous investigation who were treated with scaling and root planing plus tetracycline fibers. The parent study demonstrated that 6 months after therapy, scaling and root planing plus tetracycline fiber therapy was significantly better at reducing probing depth and gaining clinical attachment than scaling and root planing alone. However, the long-term data presented here show a regression from the original gains in clinical attachment levels in the fiber group. Ultimately, the use of fibers provided no significant advantage with regards to probing depth reduction or clinical attachment gain. Within the power of this study, which would have required 1.78 mm of change in clinical attachment to show a difference, there was no significant difference between the treatments at 5 years. This study underscores the need for additional long-term evaluation of this mode of therapy.

The effect of directly observed therapy on the rates of drug resistance and relapse in tuberculosis

BACKGROUND

Tuberculosis has reemerged as an important public health problem, and the frequency of drug resistance is increasing. A major reason for the development of resistant infections and relapse is poor compliance with medical regimens. In Tarrant County, Texas, we initiated a program of universal directly observed treatment for tuberculosis. We report the effect of the program on the rates of primary and acquired drug resistance and relapse among patients with tuberculosis.

METHODS

We collected information on all patients with positive cultures for Mycobacterium tuberculosis in Tarrant County from January 1, 1980, through December 31, 1992. Through October 1986, patients received a traditional, unsupervised drug regimen. Beginning in November 1986, nearly all patients received therapy under direct observation by health care personnel.

RESULTS

A total of 407 episodes in which patients received traditional treatment for tuberculosis (January 1980 through October 1986) were compared with 581 episodes in which therapy was directly observed (November 1986 through December 1992). Despite higher rates of intravenous drug use and homelessness and an increasing rate of tuberculosis during this 13-year period, the frequency of primary drug resistance decreased from 13.0 percent to 6.7 percent (P < 0.001) after the institution of direct observation of therapy, and the frequency of acquired resistance declined from 14.0 percent to 2.1 percent (P < 0.001). The relapse rate decreased from 20.9 percent to 5.5 percent (P < 0.001), and the number of relapses with multidrug-resistant organisms decreased from 25 to 5 (P < 0.001).

CONCLUSIONS

The administration of therapy for M. tuberculosis infection under direct observation leads to significant reductions in the frequency of primary drug resistance, acquired drug resistance, and relapse.

Detection of amplified HTLV-I/-II viral sequences using time-resolved fluorometry

Since its discovery, the polymerase chain reaction (PCR) has been used for different purposes in the field of DNA research. We tested the PCR for the diagnosis of HTLV-I/-II infections. PCR was used to amplify 141- and 149-base pair regions from the HTLV-I and HTLV-II virus genomes, respectively. The annealing temperature in the PCR amplification was optimized using 20% polyacrylamide gels and silver staining. Even a slight change (3 degrees C) in the annealing temperature had an effect on the specificity of the reaction. The PCR products were detected with biotin and Eu-labeled oligonucleotide probes in a solution hybridization format. The linearity of the assay was tested with serial dilutions of purified chromosomal DNA containing integrated HTLV-II sequences. The linearity was found to be dependent on the number of cycles used in the PCR amplification. The best linearity, at a target level of a few copies, was achieved using a low number of cycles. The specificity of the assay was tested using HTLV-I and HTLV-II-infected lymphocytes from the cell lines Hut102 and MO480, respectively. No cross reactivity between these analytes was observed.

Nucleotide sequence and expression of the human gene encoding apolipoprotein H (beta 2-glycoprotein I)

Human apolipoprotein H (ApoH), also called beta 2-glycoprotein I, is a 50-kDa serum glycoprotein whose function is not clearly defined. We have cloned and sequenced ApoH cDNAs both from human liver and from a human hepatoma cell line (HepG2). Both cDNA sequences predict a protein 345 amino acids (aa) in length. This sequence includes a 19-aa hydrophobic, N-terminal signal sequence which is not present in the mature protein [Lozier et al., Proc. Natl. Acad. Sci. USA 81 (1984) 3640-3644]. It differs from this previously reported aa sequence at two positions, both of which strengthen the conservation among the four short consensus repeats within the ApoH molecule. COS-1 cells transiently transfected with the ApoH cDNA in a eukaryotic expression vector produced a single species of ApoH mRNA and secreted in the ApoH protein. The level of ApoH mRNA expressed by HepG2 cells is downregulated by incubation with inflammatory mediators, implying that ApoH is a negative acute-phase protein.

New sensitive and specific assay for human immunodeficiency virus antibodies using labeled recombinant fusion protein and time-resolved fluoroimmunoassay

A new, rapid method for the detection of human immunodeficiency virus type 1 (HIV-1) antibody by time-resolved fluoroimmunoassay (TR-FIA) was developed. In this assay format, microtitration strips were coated with a recombinant fusion protein, and the same protein was labeled with europium and added into the wells simultaneously with the test specimens. The recombinant fusion protein contained the HIV-1 p24 gag protein sequence that carried an insertion, near the carboxyl terminus, of a 23-amino-acid sequence from a highly conserved region of the HIV-1 gp41 envelope protein. This recombinant antigen enabled the detection of antibodies to both gag and env gene products. When this assay was compared with a commercially available recombinant enzyme-linked immunoabsorbent assay (ELISA) by using four quality-control panels, the TR-FIA detected all 20 positive specimens, while the recombinant ELISA detected only 16 of them. This increased sensitivity could be demonstrated directly by the assay of dilution series of HIV-1-positive sera. The analysis of two seroconversion panels by TR-FIA and six ELISAs showed that TR-FIA allowed detection of antibody in infected individuals 16 days earlier than the other assays did. In addition to being highly sensitive, the assay was highly specific; of the 57 samples shown to be repeatedly positive by ELISA but known to be HIV-1 negative by Western immunoblot analysis, only 1 sample reacted positively in this assay. The specificity of the assay was 99.9% when 1.054 random serum specimens were tested.

Peptide mapping on HIV polypeptides expressed in Escherichia coli. Quality control of different batches and identification of tryptic fragments containing residues of aromatic amino acids or cysteine

Peptide mapping was used for the quality control of different batches of the recombinant HIV proteins p24 core and p24-gp41, expressed in Escherichia coli. These proteins comprise gag and env region polypeptides of the virus and may serve as suitable components in the diagnosis of HIV infections. The proteins were digested with trypsin and the mixtures were subjected to peptide mapping to prove batch equivalence of p24-gp41 and to isolate fragments of the p24-gp41 digest that differ from those of the p24 core digest. The proteins were reduced with dithiothreitol and the cysteine residues were derivatized by addition of 4-vinylpyridine. Peptide mapping was performed by means of reversed-phase high-performance liquid chromatography. Batch equivalence was proved by comparison of the maps. Peaks present in one map but not in the other were considered to be due to sequence differences or variability in digestion.

Avian erythroblastosis virus E26: nucleotide sequence of the tripartite onc gene and of the LTR, and analysis of the cellular prototype of the viral ets sequence

An intact 5.7-kb provirus of the avian erythroblastosis virus E26 has been molecularly cloned for comparisons with avian myeloblastosis virus (AMV) and other avian tumor viruses. E26 and AMV transform hemopoietic cells exclusively. Both cause myeloblastosis, but E26 also causes erythroblastosis. Sequence analysis of the proviral DNA showed that: The tripartite transforming gene of E26 forms a contiguous reading frame of 1046 codons, including 272 gag, 283 mybE, and 491 ets codons. No subgenomic ets-specific mRNA was detected in E26-infected cells. By contrast, the onc gene of AMV consists almost entirely of a mybA sequence expressed via subgenomic mRNA that extends over the 5' and 3' ends of mybE. mybE is only slightly diverged from the mybA homolog of AMV and even less from the cellular proto-myb sequence with no characteristic mutation that sets apart the two viruses from proto-myb. The U5 region of the long terminal repeat (LTR) of E26 and AMV are colinear and differ only in scattered point mutations. The U3 region of the E26 LTR is different from that of AMV but is colinear and closely related with that of avian carcinoma virus MH2 and also with that of Prague Rous sarcoma virus (RSV), except for an unexpected 16-nucleotide substitution of 22 RSV nucleotides. Upstream of the 3' LTR, the c region of E26 appears to be the same as that of RSV for 70 nucleotides and very similar to those of AMV and MH2 for about 20 to 30 nucleotides. Since the U3s of E26, MH2 and RSV are very closely related and neither MH2 nor RSV show a particular erythroblast tropism, it is possible that the U3 does not play a critical role in the erythroblast tropism of E26. Electrophoretic size analyses of chicken DNA digested with restriction enzymes indicate that DNA fragments totaling over 50 kb hybridize with viral ets DNA.

Complete env gene deletions of three replication-defective strains of Rous sarcoma virus and a model for the origin of their genetic structures

Replication-defective deletion mutants of Rous sarcoma virus (RSV) have been described which transform cells in culture and elaborate envelope (-) defective particles. The env deletions of two clonal variants of the Bryan strain of RSV, RSV(-)3, and RSV(-)16, and of a replication-defective variant of Schmidt-Ruppin RSV (SRN8) were analyzed by fingerprinting oligonucleotides hybridized by a molecularly cloned env DNA probe that spans from near the 3' end of pol to the 3' end of env. It was observed that all three replication-defective RSV strains are essentially complete env deletions but retain the 3' end of pol. Based on a common pol-src junction oligonucleotide that may reflect a homologous sequence repeated at both ends of env in nondefective RSV, the env deletions of RSV(-)3 and 16 appear to be isogenic. The original deletion may have involved recombination between these sequences. The absence of this oligonucleotide in SRN8 indicates that the env deletion of SRN8 has different borders and represents an independent env deletion of nondefective RSV. All three defective RSVs have the genetic structure gag-pol-src. This genetic structure is consistent with the need for a complete gag to make a particle and with the assumption that an independent src gene rather than a gag- or gag-pol-src hybrid gene functions in transformation. It is suggested that a complete pol is not necessary for, but may assist, virus particle formation.