Fast algorithm for chirp transforms with zooming-in ability and its applications.

A general fast numerical algorithm for chirp transforms is developed by using two fast Fourier transforms and employing an analytical kernel. This new algorithm unifies the calculations of arbitrary real-order fractional Fourier transforms and Fresnel diffraction. Its computational complexity is better than a fast convolution method using Fourier transforms. Furthermore, one can freely choose the sampling resolutions in both x and u space and zoom in on any portion of the data of interest. Computational results are compared with analytical ones. The errors are essentially limited by the accuracy of the fast Fourier transforms and are higher than the order 10(-12) for most cases. As an example of its application to scalar diffraction, this algorithm can be used to calculate near-field patterns directly behind the aperture, 0 < or = z < d2/lambda. It compensates another algorithm for Fresnel diffraction that is limited to z > d2/lambdaN [J. Opt. Soc. Am. A 15, 2111 (1998)]. Experimental results from waveguide-output microcoupler diffraction are in good agreement with the calculations.

A placebo-controlled trial of the immune modulator, lentinan, in HIV-positive patients: a phase I/II trial.

Lentinan is a beta 1-->3 glucan isolated from Lentinus edodes (Shiitake mushroom) which has immune modulating properties. We have conducted two phase I/II placebo-controlled trials on a total of 98 patients. In one study at the San Francisco General Hospital (SFGH), ten patients each were administered 2, 5, or 10 mg of lentinan or placebo i.v. once a week for eight weeks. In the second study at the Community Research Initiative in New York (CRI), two groups of 20 patients each were administered 1 or 5 mg of lentinan i.v. twice a week for 12 weeks, and ten patients were administered placebo (vehicle containing mannitol plus dextran 40) i.v. twice a week. Entry criteria were an HIV positive test, CD4 levels of 200-500 cells, age 18-60 years, and without current opportunistic infections. This study confirms, in Caucasian subjects also, the good tolerability of lentinan observed in Japanese cancer patients. Side effects were mainly mild, especially when infusion was carried out over a 30-minute period. In the SFGH study, where administration was over a ten minute period, there were nine side effects severe enough to be reported to the FDA (one case each of anaphylactoid reaction, back pain, leg pain, depression, rigor, fever, chills, granulocytopenia and elevated liver enzymes) and there were four patients who discontinued therapy because of side effects. In the CRI study, where infusion was over a 30-minute period, there were no side effects reportable to the FDA and there were four dropouts due to side effects or personal preference. Most side effects resolved promptly after the discontinuation of medication, and all of them were relieved within 24 hours. Patients in the study have shown a trend toward increases in CD4 cells and in some patients neutrophil activity. Because of the small numbers, these values do not have statistical significance. Inasmuch as no side effects such as anemia, leukopenia, pancreatitis or neuropathy were seen, and in view of the positive effects of lentinan on certain surrogate markers (recognizing that these were small studies), we recommended a long-term clinical trial of lentinan in combination with didanosine (ddI) or zidovudine in HIV positive patients. Most patients in these trials did not have measurable p24 levels. In the CRI trials of ten patients with elevated p24 levels, eight on lentinan and two on placebo had decreased p24 levels. Of these decreases, those with lentinan and one with placebo were marked. These results were provocative and needed confirmation. Subsequent to this study, a trial of lentinan in combination with didanosine (ddI) showed a mean increase of 142 CD4 cells/mm3 over a twelve month period, in contrast to a decrease in CD4 cells in patients on ddI alone (Gordon et al. 1995).

Two controlled trials of rifabutin prophylaxis against Mycobacterium avium complex infection in AIDS.

BACKGROUND: Disseminated Mycobacterium avium complex infection eventually develops in most patients with the acquired immunodeficiency syndrome (AIDS). This infection results in substantial morbidity and reduces survival by about six months. METHODS: We conducted two randomized, double-blind, multicenter trials of daily prophylactic treatment with either rifabutin (300 mg) or placebo. All the patients had AIDS and CD4 cell counts < or = 200 per cubic millimeter. The primary end point was M. avium complex bacteremia as assessed monthly by blood culture. The secondary end points were signs and symptoms associated with disseminated M. avium complex infection, adverse events, hospitalization, and survival. RESULTS: In the first trial, M. avium complex bacteremia developed in 51 of 298 patients (17 percent) assigned to placebo and 24 of 292 patients (8 percent) assigned to rifabutin (P < 0.001). In the second trial, bacteremia developed in 51 of 282 patients in the placebo group (18 percent) and 24 of 274 patients in the rifabutin group (9 percent) (P = 0.002). Rifabutin significantly delayed fatigue, fever, decline in the Karnofsky performance score (by > or = 20 percent), decline in the hemoglobin level (by more than 10 percent), elevation in alkaline phosphatase, and hospitalization. The incidence of adverse events was similar with rifabutin and placebo. Overall survival did not differ significantly between the two groups, although there were fewer deaths with rifabutin (33) than with placebo (47) during the double-blind phase (P = 0.086). The distribution of minimal inhibitory concentrations of rifabutin among the isolates of M. avium complex did not differ significantly between the treatment groups. CONCLUSIONS: Rifabutin, given prophylactically, reduces the frequency of disseminated M. avium complex infection in patients with AIDS and CD4 counts < or = 200 per cubic millimeter.

I.v. versus non-i.v. drug use and selected patient variables related to AIDS risk behaviors.

A sample of 206 drug users volunteered for a survey questionnaire of AIDS-related risk behaviors. The Risk Behavior Inventory (RBI) was used to elicit self-report information on risk behaviors including drug use, needle use, and sexual practices. Non-IV cocaine users reported less risk behaviors than patients involved in IV drug use. Nevertheless, non-IV users remained substantially at risk for HIV exposure because of sexual practices and sexual interaction with IV drug users. Multiple regression analysis indicated that method of drug administration (IV vs non-IV) was the major contributor of accountable variance in risk behaviors, while other patient variables, such as age, gender, educational level, employment, and marital status, did not contribute significantly to the explained variance.

Condom knowledge, history of use, and attitudes among chemically addicted populations.

The need for behavioral change of risky sexual practices has been of the highest priority since the onset of the AIDS epidemic. The major focus of education for safe sex has been emphasis on condom use. We surveyed 124 individuals applying to treatment for various chemical dependencies and 60 individuals applying for non-chemical-dependency medical treatment on various aspects of condom knowledge, history of use, and attitudes. Respondents reported that AIDS has motivated them to increase their use of condoms, however, only 13.9% always use them. Education is needed in the areas of increasing protection. Along with the use of a condom, the need for a reservoir tip and the risks associated with multiple sex partners should be stressed.

PIP: This report contains the findings of a survey designed to investigate the knowledge of condoms, history of use, and attitudes among chemically attitudes among chemically addicted populations. The study took place in the Division of Alcohol and Drug Dependence of the SUNY Health Science Center at Brooklyn, Department of Psychiatry, Kings Country Addictive Disease Hospitals. Researchers interviewed 124 individuals seeking treatment for chemical dependency, as well as 60 individuals applying for non-chemical dependency treatment to serve as controls. 25% of those interviewed reported intravenous injection as their primary route of drug administration, 25% reported smoking crack of sniffing cocaine, 17.4% cited alcohol abuse. The remaining 32.6% made up the control group. In a few instances, drug users scored better than the controls on condom knowledge, but overall, the survey found no significant differences in the level of knowledge about AIDS and condoms use among the drug, alcohol, and control groups. As expected, the survey found that those individuals who have a history of condom use scored higher on the knowledge quiz than those with less experience. Very few individuals in any of the groups mentioned monogamy as a strategy for risk reduction, or mentioned multiple sex partners as high-risk activity. While sensitivity and embarrassment did not play a significant role in condom use frequency, 26.1% of those interviewed agreed with the statement "If my partner doesn't mention using a condom neither will I." 32% of males and 57.1% of females reported having has a sex partner refuse to use a condom. These findings, the report explains, suggest the need to address sexually risky behavior within the chemically addicted populations.

AIDS-related risk behaviors among substance abusers.

Ninety-two substance abusers were surveyed about AIDS-related risk behaviors. The questionnaire administered elicited information on demographics, sexual practices, substance abuse, and risk behaviors involving the use of needles. Results indicated an appropriate base of prevention knowledge and patients' efforts to modify vulnerability to HIV exposure. Nevertheless, patients continue to engage in behaviors resulting in HIV exposure and transmission.

DMI-measured defenses and HIV-related risk behaviors in i.v. compared to non-i.v. substance abusers.

The Defense Mechanism Inventory (DMI) and The Risk Behavior Inventory (RBI) were administered to substance abusers hospitalized on a drug detoxification service. The groups were categorized on the basis of self-reported IV versus non-IV substance abuse. Significant between-group differences were obtained on the DMI and RBI. The non-IV group responded less often than the IV group with the Turning Against Object (TAO) response option, resulting in higher scores when Turning Against Self (TAS), Reversal (REV), Principalization (PRN) and Projection (PRO) were summed into a single score. Significant within-group differences were obtained for DMI response levels and defenses. Both groups relied less on TAO at the thought level and more on PRN and REV as primary defenses. The IV group reported twice as many risk behaviors as the non-IV group and risked HIV exposure through needle use and sexual transmission modes. Consideration was given to the role of principalization and denial within the addicted individual's defense structure and the relationship of these defenses to HIV-related risk behavior.

A behavioral measure of AIDS information seeking by drug and alcohol inpatients.

A nonreactive, observational research method was used to measure AIDS information-seeking behavior of patients on four drug and alcohol inpatient units at a large public hospital in New York City. Results showed only 23 inquiries from 271 male and female patients over a six-week interval. Possible explanations and implications of these results are discussed.

Auditory brainstem potentials in sons of alcoholic fathers.

With the use of event-related brain potentials we have observed sensory as well as cognitive deficits in abstinent alcoholics. By recording auditory brainstem potentials (BSP) from abstinent alcoholics we demonstrated significant delays in brainstem transmission time. We have also reported that P3 amplitudes are significantly reduced in abstinent alcoholics compared to control subjects. Although the neurophysiological deficits observed in abstinent alcoholics are presumed to be alcohol-related effects, it is possible that some of these deficits may exist prior to alcohol exposure, and may be present in subjects at high risk for alcoholism. We have recently observed significantly reduced P3 components in young sons of alcoholics similar to those observed in abstinent alcoholics. In the present study, we examined auditory BSPs in young boys at high risk for alcoholism and matched controls. We found no statistically significant difference in brainstem transmission time between high risk individuals and matched control subjects. These findings suggest that while some brain deficits observed in abstinent alcoholics may antecede the development of alcoholism (P3) and may represent a predisposing factor, other deficits (BSP) appear to be the consequence of alcohol and/or nutritional-related effects.

Event-related brain potentials to high incentive stimuli in abstinent alcoholics.

We have previously found that the P3 component of the event-related potential (ERP) is reduced in alcoholics in visual target-selection paradigms. P3 voltage depends on the "subjective significance" of the stimulus (e.g., task relevance, probability of occurrence, motivational factors). We were interested in assessing P3s in alcoholics to motivationally significant stimuli that did not differ with respect to other aspects of significance. Equiprobable, task-relevant visual stimuli with different acquired incentive values were presented to alcoholics under baseline and two incentive conditions. Alcoholics manifested similar lower P3 voltages without P3 latency delays to all stimuli, regardless of incentive values. Latency Corrected Averages indicated that these results were not due to latency jitter in the averages. These results suggest multiple system deficits in alcoholics, perhaps in involving frontal and/or medial temporal lobe, the brain sources implicated in the generation of P3. Our results perhaps reflect a deficit in motivational-cognitive systems in alcoholics, possibly affecting their ability to actively sustain information processing.

The N2 component of the event-related brain potential in abstinent alcoholics.

The latencies of the N2 component of the ERP and reaction time were manipulated in abstinent alcoholics and controls. The experimental design consisted of visual stimuli that differed in difficulty of discrimination. N2 latencies were found to be significantly delayed in alcoholics compared to controls, particularly for the easy discrimination. While controls manifested significantly earlier N2 latencies for the easy discrimination compared to the difficult discrimination, alcoholics did not manifest any significant difference in the latency of N2 as a function of the level of difficulty. There were no significant differences between groups in terms of RT or number of errors. In addition, alcoholics displayed significantly reduced P3 amplitudes to target stimuli compared to controls. These results suggest that match/mismatch processes are impaired in alcoholics and that they have difficulty evaluating the potential significance of a stimulus.

Event-related brain potentials in boys at risk for alcoholism.

Recent neurophysiological findings have demonstrated that abstinent chronic alcoholics manifest deficits in event-related brain potentials. To explore possible biological antecedents of alcoholism the present study examined boys at high risk for alcoholism. Event-related brain potentials were recorded from biological sons of alcoholic fathers and matched control boys. Differences in the P3 component of the potentials were obtained between the high-risk and control subjects.

Methadone maintenance treatment of narcotic addiction: a unit of medical care based on over 50,000 patient treatment years.

The experience with methadone maintenance treatment by two major New York City methadone maintenance treatment programs using the Dole-Nyswander philosophy is reviewed. After more than 56,000 person-years in treatment over a 10-year period of time, a unit of medical experience exemplified by these two programs is evident. There was a high degree of patient acceptance, a small amount of recognized residual illicit drug abuse, and steeply reduced criminal activities of those patients who remained in treatment. A wide variety of other methadone treatment programs are recognized. Many use methadone differently from those in the present study. The treatment results reported herein may represent a standard by which narcotic (methadone and other) treatment programs can be assessed.

Drug dependency: some etiological considerations.

In an effort to illuminate etiological aspects of drug dependency, some findings from genetics are examined for meaningful connections with psychological areas, particularly with regard to the contribution of Object Relations theory. The latter is described in some detail, using methadone maintenance treatment as an illustrative context. Connections between the two areas are described which increase an understanding of the relevance of each and which raise questions about the artificiality of the usual separation of biological and psychological approaches in this area.