In vivo sequence variability of human immunodeficiency virus type 1 envelope gp120: association of V2 extension with slow disease progression

According to the rate of depletion of CD4 cell counts, we grouped 12 cases of human immunodeficiency virus type 1 (HIV-1) infection as 6 rapid (21.0 to 33.8 cells per microl per month) and 6 slow (0.9 to 7.9 cells per microl per month) progressors and determined the individual viral quasispecies patterns by sequencing the genome region encoding the V1, V2, and V3 loops of envelope protein. Although the quasispecies structures varied widely from one individual to another, a strong correlation was observed between a low rate of disease progression and a high degree of genetic diversity of HIV-1. Furthermore, the V2 loop extension was observed specifically in individuals with slow or no disease progression, whereas basic amino acid substitutions in V3 characteristic of a viral phenotype shift from non-syncytium inducing to syncytium inducing were observed in patients with advanced stages of disease regardless of their rate of disease progression. Studies with recombinant viruses suggested that elongation of V2 potentially restricts the capacity of HIV-1 to replicate in macrophages. Thus, our results suggest the association of distinct sequence features of both V3 and V2 with particular patterns of disease progression. Elongation of the V2 loop may be a good predictor of slow disease progression, while basic substitutions of V3 without elongation of V2 are characteristic of rapid progression.

Sendai virus-based expression of HIV-1 gp120: reinforcement by the V(-) version

BACKGROUND

We have established a system for recovering Sendai virus (SeV), a nonsegmented negative strand RNA virus, entirely from cDNA at an extremely high rate, and have succeeded in creating a V(-) SeV whose gene expression was greatly enhanced by the deletion of the nonessential V gene. Because of its extreme medical importance, there has been a strong need for the establishment of a better system to express the gp120 envelope glycoprotein of the human immunodeficiency virus type 1 (HIV-1) in sufficient quantity and purity. It also remains to be established to produce gp120 in in vitro natural host cells for HIV-1 such as human primary blood mononuclear cells, macrophages or established T cell lines.

RESULTS

Using the above system, we created recombinant Sendai viruses expressing the gp120 in CV1 cells, a monkey kidney line. The expression level from the standard V(+) version has already reached 2.2/microg per 10(6) infected cells, which was readily purified from the culture fluid with a recovery rate of about 60%, and has so far appeared to be functionally and serologically authentic. The inserted gp120 gene was stably maintained during numerous passages of the recombinant virus. The V(-) version-based expression was even more robust, consistently reaching over 6.0 microg per 10(6) cells, a level that is one of the highest currently attainable for gp120 production in mammalian cells. Furthermore, a broad host range of SeV allowed gp120 production in all the three natural host cells for HIV-1 described above.

CONCLUSIONS

SeV-based expression serves as a novel choice for producing large quantities of HIV-1 gp120 and will greatly facilitate biochemical, biological and immunological studies of this important glycoprotein.

Infectivities of human and other primate lentiviruses are activated by desialylation of the virion surface

The envelope protein, gp120, of human immunodeficiency virus type 1 (HIV-1) is heavily glycosylated and sialylated. The heavy sialylation greatly affects the physical properties of the protein, as it resolves into a wide acidic pH range despite the basic pI value predicted for its polypeptide backbone (B. S. Stein and E. G. Engleman, J. Biol. Chem. 265:2640-2649, 1990). However, the functional significance of the heavy sialylation remains elusive. Here, we show that desialylation of HIV-1 with neuraminidase greatly augments the initial virus-cell interaction, leading to remarkably enhanced viral replication and cytopathogenicity. This enhancement appeared to be a direct result of the removal of negatively charged sialic acids but not of the exposure of galactose residues or complement activation. Complementing these results, studies with inhibitors of mannosidase I and mannosidase II showed that the processing of HIV-1 oligosaccharides into the complex type to acquire the terminal sialic acid residues impeded the full replication capacity of the virus and that its prevention also enhanced virus replication and cytopathogenicity. Enhancement of infection by desialylation was found widely, with HIV-1 laboratory strains of different cell tropisms and primary isolates as well as HIV-2 and simian immunodeficiency virus. Thus, the sialylation catalyzed by host cell pathways appeared to reduce the infectivity of human and nonhuman primate lentiviruses. Our results further suggested that desialylation would help increase the titers of HIV-based vectors.

Mental health reform: a practical approach

This paper outlines a practical and pragmatic approach to containing mental health costs, especially when caring for Medicaid recipients. The role of psychiatrists as primary care gatekeepers in the managed care system is also discussed. We conclude that a single-payor system seems to be the best alternative for timely and quality mental health care, and that early detection via education and screening for families predisposed to substance abuse/mental illness is also beneficial in controlling costs.

Alzheimer's disease: a new hope

Until recently, the diagnosis and treatment of Alzheimer's disease was limited. This article describes the outcome of new research and advances in the pharmacological treatment of this disease, especially the use of Cognex (tacrine). It also reports on a multicenter study of tacrine we participated in with patients at Raleigh Psychiatric Services, Inc. in Beckley.

Isolation of Vibrio cholerae O139 synonym Bengal from the aquatic environment in Bangladesh: implications for disease transmission

Currently, Bangladesh is experiencing an epidemic of acute watery diarrhea caused by Vibrio cholerae O139. Surface waters were collected and cultured for vibrious following enrichment. Twelve percent (11 of 92) of samples yielded V. cholerae O139, and all of them were positive for cholera toxin. The data suggest that V. cholerae O139 is easily culturable from surface water samples.

Competency assessment in the elderly

Although brain changes and functional capacity impairment occur in both normal and abnormal aging, it is the extent of change which determines competency status. Dementia to some degree afflicts 10 percent to 15 percent of 30 million Americans over age 65. History, age-normed neuropsychological testing, and laboratory investigations are essential to competency assessment since physical and personality dysfunctions may masquerade as dementia. Since competency decisions profoundly impact the lives of the elderly, our fastest growing segment of national population, psychiatrists, psychologists, family physicians, and lawyers will become increasingly involved in competency issues.

Use of the polymerase chain reaction and fluorescent-antibody methods for detecting viable but nonculturable Shigella dysenteriae type 1 in laboratory microcosms

Epidemiological studies of shigellosis in Bangladesh have demonstrated that surface-water sources can act as foci of infection. Studies of laboratory microcosms have shown that shigellae become nonculturable but remain viable when exposed to environmental samples of water. The present study was carried out to detect viable but nonculturable Shigella dysenteriae 1 from laboratory microcosms by the polymerase chain reaction and the fluorescent-antibody techniques. S. dysenteriae 1 was inoculated into laboratory microcosms consisting of water samples collected from ponds, lakes, rivers, and drains in Bangladesh. The survival of S. dysenteriae in microcosms was assessed by viable counting on MacConkey agar. After 2 to 3 weeks, S. dysenteriae 1 became nonculturable but remained viable. After 6 weeks, this nonculturable but viable S. dysenteriae 1 was detected by both the polymerase chain reaction and the fluorescent-antibody methods. The viable but nonculturable state of S. dysenteriae 1 demonstrated in this study may be important for understanding the epidemiology of shigellosis.

Growth and survival of Shigella flexneri in common Bangladeshi foods under various conditions of time and temperature

Survival and growth of Shigella flexneri were assessed in various foods, including boiled rice, lentil soup, milk, cooked beef, cooked fish, mashed potato, mashed brinjal, and raw cucumber. Growth at 25 and 37 degrees C and survival at 5 degrees C were observed by viable counts on MacConkey agar. The organism grew well in all tested foods and growth increased from 10(5) to 10(8) to 10(10) cells per ml or g within 6 to 18 h after inoculation at 25 and 37 degrees C.

Neuroleptic malignant syndrome

Neuroleptic malignant syndrome is a potentially life-threatening reaction to neuroleptic agents. Its symptoms develop rapidly and may occur at the initiation of the neuroleptics or after long-term use. The pathogenesis remains unclear. The authors reviewed 93 documented cases published in the literature over the past five years. Demographic and clinical features of the syndrome are identified. Diagnostic criteria are proposed along with recommendations for treatment and further research.

Once-a-day drug regimen for psychiatric patients

Patient compliance can be improved by reducing the complexity of drug dosage and by better labeling, packaging and informational exchange. Single bedtime doses not only increase compliance but also decrease side effects. The once-a-day regimen can reduce drug automatism and thus decrease acute confusional states, especially in the elderly.

Reversible toxic psychosis

Psychotropic medications may produce a toxic confusional state, especially in elderly patients. Tricylcic antidepressants particularly, and the phenothiazines to a lesser extent, may induce these behavioral changes by their anticholinergic activity. The situation may be compounded by the use of more than one psychotropic drug or the addition of an antihistamine or a belladonna alkaloid. Physostigmine can reverse the anticholinergic effects and clear the mental state.

Three cases of manic-depressive illness in mentally retarded adults

The authors point out that manic-depressive illness is often not diagnosed in mentally retarded patients because they are already regarded as "different." They discuss the use of lithium carbonate as a prophylactic agent in the treatment of manic-depressive illness in mentally retarded patients and present three case histories illustrating some of the difficulties encountered in diagnosing mania or hypomania in such patients. They provide a number of suggestions to help physicians recognize and treat these disorders.

Psychogenic fever: entity or nonentity?

A review of the literature suggests that body temperature may rise when a person is under emotional stress. The term "psychogenic fever" has been applied to this phenomenon. A study of temperature and pulse rate of psychiatric patients diagnosed predominantly as neurotic in a university teaching hospital was undertaken. Changes in pulse rate indicated that the period before ward rounds was more stressful than other times of the day. However, psychogenic fever in these patients was not found. One case of factitious fever was uncovered during the study.

Primary anorexia nervosa (weight phobia) in males

Ten cases of primary anorexia nervosa (weight phobia) in males (as against 196 females) have been treated in the United Birmingham Hospitals over 19 years. A discrete syndromes appears to exist with much to support the view that it is the counterpart of primary anorexia nervosa in the female. Six illustrative case histories are described briefly. The heavy loading with consistent abnormalities of psychiatric interest makes it very probable that weight phobia is primarily a psychiatric disorder.

Fast-track Cardiac Surgery in Children: Feasibility in Bangladeshi Setting

Background: Fast-track recovery protocols in cardiac surgery is gaining worldwide popularity and have contributed to significant reductions in the postoperative hospital stay and cost without any increase in postoperative mortality and morbidity. The aim of this study was to find out the feasibility of fast track paediatric cardiac surgery in Bangladeshi setting. Method: It was a prospective study conducted in National Institute of Cardio-vascular Diseases, Dhaka, from July 2009 to June 2010. All patients, between 3 to 18 years, underwent surgical closure of atrial or ventricular septal defect under cardio-pulmonary bypass. 20 patients from our unit served as fast track group and 30 patients from other units of the same hospital served as conventional group. Fast track patients were extubated in less than 6 hours after surgery, shifted from ICU in less than 24 hours and geared up to discharge home within 3 days of surgery. Result: 18 (90%) of the 20 patient of the fast track group were discharged within 3 days of surgery, 2 patients cannot be discharged within this time frame. Mean post operative hospital stay for study group was 3.1 days, whereas the mean hospital stay in the control group was 7.5 days. Follow-up was 100% complete at 30 days. There was no major in-hospital or out-of-hospital complications in either group. No patient was readmitted at our centre or elsewhere for any complication arising from this process. Conclusion: Fast tracking is feasible and safe in low-risk paediatric open-heart surgery in Bangladeshi scenario. A multidisciplinary approach with a set protocol is required to achieve this goal in a safe and reproducible manner. Keywords: Cardiac surgery; Congenital heart disease; Fast track; Hospital discharge. DOI: 10.3329/cardio.v3i1.6427Cardiovasc. j. 2010; 3(1): 50-54