Controlled synthesis of dicalcium phosphate dihydrate (DCPD) from metastable solutions: insights into pathogenic calcification

Calcium phosphate (CaP) compounds may occur in the body as abnormal pathogenic phases in addition to their normal occurrence as bones and teeth. Dicalcium phosphate dihydrate (DCPD; CaPO₄·2H₂O), along with other significant CaP phases, have been observed in pathogenic calcifications such as dental calculi, kidney stones and urinary stones. While other studies have shown that polar amino acids can inhibit the growth of CaPs, these studies have mainly focused on hydroxyapatite (HAp; Ca₁₀(PO₄)₆(OH)₂) formation from highly supersaturated solutions, while their effects on DCPD nucleation and growth from metastable solutions have been less thoroughly explored. By further elucidating the mechanisms of DCPD formation and the influence of amino acids on those mechanisms, insights may be gained into ways that amino acids could be used in treatment and prevention of unwanted calcifications. The current study involved seeded growth of DCPD from metastable solutions at constant pH in the presence of neutral, acidic and phosphorylated amino acid side chains. As a comparison, solutions were also seeded with calcium pyrophosphate (CPP; Ca₂P₂O₇), a known calcium phosphate inhibitor. The results show that polar amino acids inhibit DCPD growth; this likely occurs due to electrostatic interactions between amino acid side groups and charged DCPD surfaces. Phosphoserine had the greatest inhibitory ability of the amino acids tested, with an effect equal to that of CPP. Clustering of DCPD crystals giving rise to a "chrysanthemum-like" morphology was noted with glutamic acid. This study concludes that molecules containing an increased number of polar side groups will enhance the inhibition of DCPD seeded growth from metastable solutions.

Preventing iatrogenic air embolism in the intensive care unit

Air embolism is a potentially fatal consequence of incorrect connection of endotracheal tube cuff inflator devices. Currently, air lines from these devices can be connected to indwelling cannulae without impediment. This possibility can be eliminated with a simple modification of the air line, as described here.

Comparison of three instruments in predicting accidental falls in selected inpatients in a general teaching hospital

Accidental patient falls are becoming a major cause of concern for hospitalized inpatients. It is well known that patients who fall once during their hospital stay are more likely to fall again and that fall rates tend to be higher in hospitalized elderly individuals. Concerned health care team personnel recognize that many accidental patient falls may be predicted and, thus, prevented. The best tool to predict falls has not been determined yet. The purpose of this study was to compare the abilities of the Morse Fall Scale (MFS), the Functional Reach (FR) test, and the nurses' clinical judgment in predicting those inpatients on a rehabilitation unit and a geriatric medical ward who were most likely to fall. A total of 98 patients were screened in a 3-month period, with each patient undergoing all three instruments the same day. The results showed that the two objective standardized tests (i.e., MFS, FR) were time consuming and often inconvenient and were no better at prediction than the clinical judgments made by the primary nurses.

Characterization of the calcium biomineral in the radular teeth of Chiton pelliserpentis

The radula in a group of molluscan invertebrates, the chitons (Polyplacophora), is a ribbon-like apparatus used for feeding and which bears a series of distinctive mineralized teeth called the major lateral teeth. While some chiton species deposit only iron biominerals in these teeth, many others deposit both iron and calcium. In this study, the calcium biomineral in the teeth of one of the latter types of species, the Australian east-coast chiton, Chiton pelliserpentis, has been isolated and examined for the first time. Spectroscopic and crystallographic techniques have identified the biomineral as a carbonate-substituted apatite with significant fluoride substitution also likely. Fourier-transform infrared and laser Raman spectroscopy indicated that the carbonate content was less than that of either bovine tibia cortical bone or human tooth enamel. X-ray diffraction analysis showed the biomineral to be poorly crystalline due to small crystal size and appreciable anionic substitution. The lattice parameters were calculated to be a = 9.382 A and c = 6.883 A, which are suggestive of a fluorapatite material. It is postulated that structural and biochemical differences in the tooth organic matrix of different chiton species will ultimately determine if the teeth become partly calcified or iron mineralized only.

What are the factors that influence learning in relation to nursing practice?

Although ongoing education is an expectation of all nurses in today's climate of increasing technology and patient acuity, little is known about the attitudes, beliefs, and values of the general staff nurse toward on-the-job learning. The authors detail the factors that influence the learning ability of nurses on general medical-surgical units in a teaching hospital in relation to their nursing practice. Findings of what promotes learning, what interferes with learning, and how learning is integrated into nursing practice are outlined. Implications for the future are discussed.

Predicting injection site muscle damage. I: Evaluation of immediate release parenteral formulations in animal models

PURPOSE

The current animal model generally accepted by the pharmaceutical industry and the FDA for assessment of muscle damage following intramuscular injection (IM) is the rabbit lesion volume model (RbLV). However, this model is resource intensive. The goal of this study was to find a resource sparing alternative to the rabbit lesion model for assessing injection site toleration in IM formulation screening.

METHODS

Short term animal model alternatives to RbLV for evaluating IM formulations were examined. In addition to RbLV, myeloperoxidase (MPO), p-nitrophenyl N-acetyl-beta-glucosaminide (NA beta G) and/or plasma creatine phosphokinase (CK) activities were determined in rabbits (Rb) and rats (Rt) after injection of formulations (digoxin, azithromycin and danofloxacin). The edema from these formulations 24 hr after subcutaneous injection into the rat footpad (RFE) was also determined.

RESULTS

MPO and NA beta G were not considered very useful as biochemical predictors of muscle damage for these formulations. Histology generally correlated with RbLV values. Compared to saline, RbLV was marked for all formulations within 1-3 days of injection. After day 3, lesions quickly resolved, and no significant differences were found. For these formulations, all CK animal models and RFE were generally predictive of RbLV. A formulation with RtCK > 1000 U/L or RbCK > 3000 U/L, was predicted to be poorly, tolerated.

CONCLUSIONS

Due to ease, number of animals, time and intrinsic mechanism, we concluded that for most formulations, 2 and 4 hr RtCK data alone should be reasonably predictive of muscle damage.

Predicting injection site muscle damage. II: Evaluation of extended release parenteral formulations in animal models

PURPOSE

The goal of this study was to find a resource sparing alternative to the rabbit lesion model (RbLV) for assessing injection site toleration in extended release (ER) intramuscular (IM) formulation screening.

METHODS

ER formulations (danofloxacin oily and aqueous suspensions) were evaluated in RbLV, rat and rabbit plasma creatine phosphokinase (CK), and rat foot edema (RFE) models as described in the companion article.

RESULTS

None of the short term models could consistently predict acute and chronic effects of the. For example, RFE predicted little muscle damage from aqueous vehicle (0.03 +/- 0.03 g) and 60 mg/ml (0.08 +/- 0.03 g) formulation; while RbLVdays1-3 was marked and greater (p < 0.05) for 60 mg/ml (6.0 +/- 3.1) than vehicle (2.2 +/- 2.9) formulations. Furthermore, RbLVdays 1-3) for vehicle (6.5 +/- 7.5) and 60 mg/ml (4.9 +/- 4.6) danofloxacin oily formulations were worse (p < 0.05) than oil alone (1.4 +/- 2.2); an observation not predicted by CK models, since they apparently reflected only the acute muscle damage of formulation components immediately available to surrounding tissue at the time of injection.

CONCLUSIONS

The CK models may be useful to screen those ER formulations with unacceptable acute damage due to immediately available components. However, to evaluate potential delayed effects from ER formulations, the long-term model RbLV was still recommended.

Stingray hickey

A large number of injuries from stingrays are reported each year in the United States. Usually these injuries are inflicted by the stingray's tail, after the resting stingray is stepped on. The tail has a stinger that can cause puncture wounds with envenomation. We report a case in which an injury from a stingray was due to its bite.

Changes in biologic phenotype of human immunodeficiency virus during treatment of patients with didanosine

Progression to AIDS in patients harboring human immunodeficiency virus type-1 (HIV-1) isolates expressing a syncytium-inducing (SI) phenotype is faster than in those in whom the virus expresses a non-SI (NSI) phenotype. Zidovudine monotherapy does not appear to alter this outcome. To examine the role of didanosine (ddI) monotherapy in phenotype expression, HIV-1 isolates from 73 patients receiving ddI for up to 72 weeks were analyzed. After 12 weeks, the number of isolates expressing an NSI phenotype was 29% higher than at the start of treatment. Patients receiving high-dose ddI (375 mg twice daily) were significantly more likely to express the NSI phenotype at 12 weeks than patients who received low-dose ddI (100 mg twice daily), even after adjustment for phenotype and CD4 cell count at baseline, suggesting that ddI may be selective against the faster-replicating virus. ddI at 375 mg twice daily significantly increases the probability of an NSI phenotype over the short term in patients with advanced HIV disease.

Primary structure of the V3 region of gp120 from sequential human immunodeficiency virus type 1 isolates obtained from patients from the time of seroconversion

V3 loop sequences were compared from 5 human immunodeficiency virus type 1 (HIV-1)-infected patients over time. Three patients remained asymptomatic and 2 became symptomatic with large decrease in CD4 cell counts. The patient isolates were previously evaluated for phenotypic and antigenic properties and had different sensitivities to serum neutralization and changes in phenotype. This study showed a number of amino acid changes for the 2 symptomatic patients, each of whom progressed to AIDS during the study. The only amino acid substitution consistently associated with reduced CD4 cell counts, cytopathic effect, and progression to AIDS was Arg at position 11. Specific amino acid changes could not be correlated with increasing serum neutralization resistance or cytotropism changes. Increased loop charge was associated with a switch from macrophage to T cell tropism and a decrease in the number of CD4 cells. The study shows the importance of naturally occurring mutations in the V3 loop in controlling the biologic properties of HIV-1.

Productive in vitro infection of human umbilical vein endothelial cells and three colon carcinoma cell lines with HIV-1

The objective of this study was to assess the ability of HIV-1 to establish an in vitro infection of primary human umbilical vein endothelial cells (HUVEC). The HUVEC and colon carcinoma cell lines were inoculated with different isolates of HIV-1 (HIV-1SF2, HIV-1Mck and HIV-1LAI) and productive viral infection was assessed by both the detection of p24 core antigen in the culture supernatants and the presence of specific spliced HIV mRNA. The infection which was detected in the inoculated HUVEC and all the colon carcinoma cell lines could not be blocked using an antibody targeted against the CD4 receptor. Furthermore, the HIV-inoculated HUVEC secreted elevated levels of IL-6 and this increase was found to be proportional to the size of the viral inoculum. No changes in the production of IL-1 beta, TNF-alpha, IFN-alpha and IFN-gamma were detected following HIV infection. The colon carcinoma cells, however, did not secrete increased levels of these cytokines following HIV-1 inoculation. These results confirm that non-CD4 expressing cells, such as endothelial cells and certain colon epithelial cells, serve as targets and reservoirs for HIV. Moreover, the production of IL-6 by HIV-infected endothelial cells may be a contributing factor to the aberrant immunoregulation associated with HIV infection in vivo.

Neutralizing antibodies against sequential autologous human immunodeficiency virus type 1 isolates after seroconversion

The emergence of human immunodeficiency virus type 1 (HIV-1) variants with different sensitivities to serum neutralization and biologic phenotype was studied for 2-5 years after primary HIV-1 infection in 5 subjects. In 3 subjects, the initial virus isolate from seroconversion could be neutralized by autologous serum, but isolates obtained at two subsequent times exhibited reduced sensitivity to serum neutralization, decreased replication in primary macrophages, and increased ability to induce syncytia. Two of these 3 subjects progressed to AIDS and died. Sequential virus isolates from the other 2 subjects showed variability in sensitivity to serum neutralization or biologic features. These patients remained relatively stable in clinical status. Thus, viruses isolated at seroconversion appear to be either non-syncytium-inducing, strong macrophage-tropic, serum neutralization-sensitive phenotypes with stable clinical status or to have escaped neutralization by autologous sera over time, have reduced macrophage tropism and increased syncytia formation, and be associated with disease progression.

Pseudofolliculitis barbae associated with an unusual hair whorl

Descriptions of hair direction in the literature have emphasized unusual patterns of the scalp and associated developmental brain defects. We present the case of a white patient with unilateral pseudofolliculitis barbae associated with a hair whorl in the inframandibular region. To our knowledge, this is the first reported case of pseudofolliculitis barbae associated with a hair whorl.

Black and white differences: narrowing the gap in cancer medicine

Excess mortality is a complex problem involving multiple sub-problems including culture, economics, lifestyle, issues related to cancer biology, and access to medical care among other issues. Consideration has to be given to the multiple influences that lead to this discrepancy in survival related to cancer and the increased incidence of certain tumors. Increased availability of state-of-the-art cancer treatment to the population as a whole will upgrade the level of care by those that participate in clinical trials; the physicians and finally even those patients who are not entered into the trials. Upgrading the access to information about prevention and control of cancer is of equal importance. There are those tumors with possible biological explanations for increases in cancer incidence in the Black population, in particular, multiple myeloma and prostate cancer. There are tumors which are increasing in incidence in this population with no explanation but which must relate to biological factors.

Calcium biomineralization in the radular teeth of the chiton, Acanthopleura hirtosa

A method has been devised for isolating the calcium biomineral from the iron biominerals and organic components present in the major lateral teeth of the chiton Acanthopleura hirtosa. Fourier-transform infrared spectroscopy of the calcium biomineral indicated that it was an apatite material containing carbonate and fluoride ions. Carbonate was not found to be present as a separate phase. The apatite was further separated into low and high density fractions, both of which showed crystallinity intermediate between that of bovine tibia cortical bone and human tooth enamel, as indicated by powder X-ray diffraction analysis. The calcified region of the major lateral teeth was also studied in situ using transmission electron microscopy and electron diffraction analysis, revealing a close spatial relationship between the mineral apatite phase and underlying organic matrix. It is suggested that the architectural arrangement of apatite biomineral and fibrous organic constituents imparts specialized mechanical properties to the tooth making it ideally suited for the task of obtaining food from hard surfaces.

Several CD4 domains can play a role in human immunodeficiency virus infection in cells

The human immunodefiency virus (HIV) uses the human CD4 glycoprotein as a receptor for infection of susceptible cells. Cells expressing a series of mutated forms of the CD4 gene have shown a variability in their ability to support replication of three HIV type 1 (HIV-1) and three HIV-2 strains. Moreover, when different stages of virus production were examined by a variety of assays, a consistent delay was observed in all cell lines containing CD4 mutants compared with those with intact full-length CD4. Cells expressing the CD4.415 mutant (modified at the serine 415 corresponding to a phosphorylation site of the cytoplasmic domain) showed only a minimal effect on virus replication. Cells expressing CD4.403 and CD4.401 mutants (lacking the whole cytoplasmic domain) manifested a moderate delay in production of virus progeny. The most substantial effect on HIV replication was observed in cells expressing a chimeric hybrid containing sequences corresponding to the first 177 residues of the N-terminal CD4 fused to CD8 sequences encoding the hinge, transmembrane, and cytoplasmic domains of the human CD8. Furthermore, in a cell-to-cell contact assay, fusion was absent when the CD4 proximal membrane domain was replaced by the CD8 counterpart. In addition, a strong correlation between the down-modulation of the surface CD4 and HIV expression was observed. These observations suggest that in addition to the known binding region, other domains of CD4 could play an important role in regulating HIV entry of cells.

Culture and properties of cells derived from Kaposi sarcoma

We describe the establishment of four continuous cell cultures isolated from pleural or peritoneal fluid of patients with Kaposi sarcoma (KS) and show evidence that these cells are derived from vascular endothelium. Although provision of an extracellular matrix (fibronectin, laminin, or matrigel) was essential, the cell cultures were not dependent on exogenously added growth factors (platelet-derived growth factor, epidermal growth factor with or without heparin) for continuous culture. Specific staining for endothelial cell (EC) markers (factor VIII, Ulex europaeus type 1 lectin) and the secretion of endothelin, a vascular EC product, were demonstrated. The KS cells secreted large amounts of cytokines (granulocyte-macrophage-CSF, TNF-alpha, IL-1 beta, and especially IL-6). Conditioned media from the KS cells caused normal capillary EC to proliferate. The KS cells synthesized fibroblast growth activity in amounts sufficient to induce the proliferation of normal EC and fibroblasts. These data support the existence of a paracrine pathway of EC proliferation in KS and suggest that KS cells could sustain their own growth via an autocrine mechanism.

Culture and properties of cells derived from Kaposi sarcoma

We describe the establishment of four continuous cell cultures isolated from pleural or peritoneal fluid of patients with Kaposi sarcoma (KS) and show evidence that these cells are derived from vascular endothelium. Although provision of an extracellular matrix (fibronectin, laminin, or matrigel) was essential, the cell cultures were not dependent on exogenously added growth factors (platelet-derived growth factor, epidermal growth factor with or without heparin) for continuous culture. Specific staining for endothelial cell (EC) markers (factor VIII, Ulex europaeus type 1 lectin) and the secretion of endothelin, a vascular EC product, were demonstrated. The KS cells secreted large amounts of cytokines (granulocyte-macrophage-CSF, TNF-alpha, IL-1 beta, and especially IL-6). Conditioned media from the KS cells caused normal capillary EC to proliferate. The KS cells synthesized fibroblast growth activity in amounts sufficient to induce the proliferation of normal EC and fibroblasts. These data support the existence of a paracrine pathway of EC proliferation in KS and suggest that KS cells could sustain their own growth via an autocrine mechanism.

Biologic heterogeneity of human immunodeficiency virus type 2 (HIV-2) strains

Seven HIV-2 isolates recovered from peripheral blood mononuclear cells (PBMC) of patients from the Ivory Coast have been biologically characterized. All seven strains replicated well in primary human lymphocyte and macrophage cultures and in established human T cell lines. They showed differences in infectivity and replicating ability in primary PBMC cultures from chimpanzees, rhesus macaques, and baboons. Moreover, variations in levels of virus replication in PBMC from 13 seronegative donors were observed. Four strains (UC2, UC3, UC7, and UC8) were highly cytopathic and caused extensive surface CD4 antigen depletion in acutely infected PBMC and SupT1 cells. Two strains (UC1 and UC6) showed minimal or no cytopathology, no CD4 down-modulation, and much lower levels of virus protein expression in SupT1 cells. These findings reflect the heterogeneity of HIV-2 strains and suggest that these biological properties could influence pathogenesis in the host.

Antibody-dependent cellular cytotoxicity is directed against both the gp120 and gp41 envelope proteins of HIV

To define the target antigens for antibody-dependent cellular cytotoxicity (ADCC), assays were performed using affinity-purified human immunoglobulin (Ig) or polyclonal rabbit sera directed against specific proteins of HIV. ADCC was not found using affinity-purified anti-core (p25) human Ig or sera obtained from rabbits hyper-immunized with recombinant p25. However, when affinity-purified human Ig or rabbit antisera specific for the envelope glycoproteins, gp120 or gp41, were used in ADCC assays, killing of HIV-infected cells was observed. These results indicate that antibodies in the infected individual that mediate ADCC are directed against both the gp120 and gp41 HIV envelope proteins and not against the viral core protein.

Simultaneous isolation of HIV-1 and HIV-2 from an AIDS patient

Two distinct human immunodeficiency viruses, HIV-1SF480 and HIV-2UC2 were isolated simultaneously from the blood of an Ivory Coast patient with AIDS. The HIV subtypes were segregated by their differential ability to infect established human cell lines and by the cell surface expression of type-specific viral antigens. The viruses could be distinguished by both immunoblot and Southern blot analyses. The results indicate that an individual can be infected by both HIV subtypes.

Characterization of a noncytopathic HIV-2 strain with unusual effects on CD4 expression

A new isolate of the human immunodeficiency virus type 2, designated HIV-2UC1, was recovered from an Ivory Coast patient with normal lymphocyte numbers who died with neurologic symptoms. Like some HIV-1 isolates, HIV-2UC1 grows rapidly to high titers in human peripheral blood lymphocytes and macrophages and has a differential ability to productively infect established human cell lines of lymphocytic and monocytic origin. Moreover, infection with this isolate also appears to involve the CD4 antigen. However, unlike other HIV isolates, HIV-2UC1 does not cause cytopathic effects in susceptible T cells nor does it lead to loss of CD4 antigen expression on the cell surface. These results indicate that HIV-2 may be found in individuals with neurologic symptoms and that the biological characteristics of this heterogeneous subgroup can differ from those typical of HIV-1.

Human immunodeficiency virus recovery from bronchoalveolar lavage fluid in patients with AIDS

We cultured bronchoalveolar lavage fluid for the human immunodeficiency virus (HIV) from 23 consecutive patients with acquired immunodeficiency syndrome (AIDS) and pulmonary symptoms. We also included a nonconsecutive AIDS patient with recent worsening of respiratory symptoms who had had lymphocytic interstitial pneumonitis (LIP) diagnosed six months earlier. Infectious HIV was present in the cellular fraction from two of the 23 consecutive patients and in the patient with LIP. No virus was isolated from the cell-free portion of the centrifuged fluids. The patients from whom HIV was cultured were not distinguishable from other patients by clinical, radiographic, or laboratory data, and their subsequent course did not appear to differ. One patient with a positive HIV culture had organizing pneumonia without evidence of LIP at autopsy three weeks after lavage. This study demonstrates that HIV can be cultured from cells obtained by bronchoalveolar lavage and suggests that its presence is not associated with a single specific pulmonary histologic pattern.

Identification of human immunodeficiency virus subtypes with distinct patterns of sensitivity to serum neutralization

The human immunodeficiency virus (HIV) type 1 displays a high degree of genetic variation, especially in the glycoprotein (gp120) domain of the envelope gene. To determine whether this genomic heterogeneity leads to the expression of independent HIV subtypes, 12 sera from HIV type 1 antibody-positive individuals were tested for their ability to neutralize 20 HIV isolates of various origins. Four distinct HIV subtypes with different sensitivity to serum neutralization were identified. These results suggest that a finite number of HIV subtypes exist and that the combined use of selected HIV isolates representing several subtypes may be necessary for the development of an effective vaccine.

Human monoclonal antibody directed against gag gene products of the human immunodeficiency virus

Tonsillar B lymphocytes from an asymptomatic individual infected with HIV were transformed with EBV. A cloned lymphoblastoid cell line was obtained that secreted human mAb (IgG4 subtype) against the known gag gene products of 55,000 and 25,000 Da and a protein of 40,000 Da. The latter p40 protein appears to be a HIV gag-related gene product that is also recognized immunologically by individuals infected by HIV. Although the mAb detects infection of cells by different HIV isolates, it does not neutralize HIV or show activity in an antibody-dependent cytotoxicity assay.

Human monoclonal antibody directed against gag gene products of the human immunodeficiency virus

Tonsillar B lymphocytes from an asymptomatic individual infected with HIV were transformed with EBV. A cloned lymphoblastoid cell line was obtained that secreted human mAb (IgG4 subtype) against the known gag gene products of 55,000 and 25,000 Da and a protein of 40,000 Da. The latter p40 protein appears to be a HIV gag-related gene product that is also recognized immunologically by individuals infected by HIV. Although the mAb detects infection of cells by different HIV isolates, it does not neutralize HIV or show activity in an antibody-dependent cytotoxicity assay.

HIV heterogeneity and viral pathogenesis

HIV research in the past year has elucidated many questions relevant to strategies for treatment and control. For instance, there is a greater understanding of the diversity of HIV isolates as well as the wide range of potential cells sensitive to infection. The search for a safe, effective vaccine now calls for more caution in the light of the discovery of neutralization-resistant variants and antibody-mediated enhancement of infection. Efforts to control HIV must take into account the various mechanisms of virus entry into host cells, and the processes involved in cytopathic effects. Moreover, the role of cells of the mononuclear phagocyte system as reservoirs for HIV particles should be recognized. Together with new information about cytokine induction of HIV, the concept of latent infection of monocytes and macrophages has profound implications for virus persistence and dissemination, especially in the seronegative individual. While many factors about HIV have been uncovered in the past year, several questions remain unanswered and new ones have arisen. For instance, in how many ways does the virus kill in host cell? What causes latency and why does it occur in some but not all hosts? How can virus-filled macrophage vesicles be reached by therapeutic agents or prevented from releasing HIV? What surveillance mechanisms allow some productively infected hosts (cells as well as individuals) to survive beyond expectation? These and other questions should provoke future research on this presently complex and challenging pathogen.

Differential ability of human immunodeficiency virus isolates to productively infect human cells

Isolates of HIV showed distinct differences in the ability to replicate in continuous human hematopoietic cell lines. Moreover, although all PMC cultures obtained from healthy individuals could be infected with HIV, considerable variation in the amount of virus released from different PMC cultures was observed. These biological properties of HIV could not be correlated with clinical state, binding properties of the virus isolates to target cells, or differences in target cell CD4 antigen expression. Some isolates of HIV that could not directly infect the HUT-78 cell line showed productive infection when PMC infected with these viruses were added to this human T cell line. These observations emphasize the importance of cell to cell contact in the spread of virus. The results demonstrate for the first time the differences in the host range specificity of HIV isolates in several individual PMC cultures, and indicate that the optimal isolation of HIV is achieved with normal human PMC rather than established human cell lines.

Differential ability of human immunodeficiency virus isolates to productively infect human cells

Isolates of HIV showed distinct differences in the ability to replicate in continuous human hematopoietic cell lines. Moreover, although all PMC cultures obtained from healthy individuals could be infected with HIV, considerable variation in the amount of virus released from different PMC cultures was observed. These biological properties of HIV could not be correlated with clinical state, binding properties of the virus isolates to target cells, or differences in target cell CD4 antigen expression. Some isolates of HIV that could not directly infect the HUT-78 cell line showed productive infection when PMC infected with these viruses were added to this human T cell line. These observations emphasize the importance of cell to cell contact in the spread of virus. The results demonstrate for the first time the differences in the host range specificity of HIV isolates in several individual PMC cultures, and indicate that the optimal isolation of HIV is achieved with normal human PMC rather than established human cell lines.

Effects of ion transport inhibition on rat mandibular gland secretion

The effects of substituting gluconate for extracellular Cl, and of treatment with various ion transport blockers, on cytosol pH (pHi) and secretion by the acetylcholine stimulated rat mandibular gland were studied in vitro. Gluconate replacement increased pHi from 7.12 +/- 0.02 to 7.27 +/- 0.04, caused secretory rate to fall by 75%, and increased salivary HCO3 from 14 +/- 0.9 mmol/L to 67 +/- 1.5 mmol/L. Furosemide (1 mmol/L), which blocks Na-K-2Cl symports and Cl-HCO3 antiports, had effects similar to those of gluconate replacement, except that secretion was reduced only by 59%. Bumetanide (1 mmol/L), which blocks only Na-K-2Cl symports, caused a 67% reduction in secretion rate, but it had little effect on pHi and caused only a small rise in salivary HCO3 concentration. SITS (1 mmol/L), which blocks Cl-HCO3 antiports, increased pHi to 7.26 +/- 0.03 and induced a small rise in the secretory rate. Methazolamide and acetazolamide (1 mmol/L), both of which inhibit carbonic anhydrase and may also block anion channels, increased pHi to 7.43 +/- 0.02 and 7.20 +/- 0.03, respectively, but had no effect on secretory rate, and reduced salivary HCO3 slightly. Ba (3 mmol/L), tetraethylammonium (10 mmol/L), and decamethonium (5 mmol/L) all caused marked but reversible reductions in secretory rate, consistent with the known actions of these agents on K channels. Ba, however, also appeared to act as a Ca antagonist, an action that it seemed to share with Mn ions (5 mmol/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Intracellular pH in the rat mandibular salivary gland: the role of Na-H and Cl-HCO3 antiports in secretion

Intracellular pH (pHi) in the perfused rat mandibular gland was determined from the distribution of DMO (5,5-dimethyl-2,4-oxazolidinedione). In unstimulated glands, pHi averaged 7.12 +/- 0.02. Stimulation with a "standard" (submaximal) concentration (0.3 mumol/l) of acetylcholine (ACh) caused a fall in pHi to 6.81 +/- 0.06 over 60 min, but a maximal concentration (1.0 mumol/l) caused an initial rise in pHi to 7.60 +/- 0.02, followed by a fall to 7.45 +/- 0.02 over 60 min. After replacement of perfusate Cl with gluconate, the standard ACh concentration caused a rise in pHi to 7.50 +/- 0.02 followed by a fall to 7.27 +/- 0.04 after 60 min, concomitant with a 76% fall in secretory rate and a rise in salivary HCO3 concentration from 14 +/- 0.9 to 67 +/- 1.5 mmol/l. Furosemide (1 mmol/l) had a similar effect to gluconate replacement except that secretory rate fell only by 60%. Bumetanide (1 mmol/l), which inhibited secretion by 67%, did not cause pHi to rise following ACh stimulation but prevented the fall seen with ACh alone. Acetazolamide and methazolamide (1 mmol/l) had no effect on the salivary secretory response to ACh but they caused pHi to rise, respectively, to 7.20 +/- 0.03 and 7.43 +/- 0.02. Bumetanide and methazolamide together caused pHi to rise to 7.58 +/- 0.02 and reduced the secretory response to ACh by 91%. The disulfonic stilbene, SITS, caused pHi to rise to 7.26 +/- 0.03. Ouabain and amiloride both caused resting pHi to fall closer to equilibrium and largely abolished the gland's responsiveness to ACh.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of AIDS-associated retrovirus from genital secretions of women with antibodies to the virus

The AIDS-associated retrovirus (ARV) was isolated from vaginal and/or cervical secretions from 4 out of 8 women whose sera contained antibodies to the virus. The quantity of virus recovered initially was so low that identification of ARV was accomplished only after passage of the isolates to cultured mitogen-stimulated normal human peripheral blood mononuclear cells. The results indicate that the vaginal canal under certain conditions could be a source of transmission of ARV.

Intraepithelial current flow in rat pancreatic secretory epithelia

To assess the importance for transepithelial salt secretion of current flow across the baso-lateral membrane, we studied the effects of ouabain (1 mmol/l), Ba (3 mmol/l) and tetraethylammonium (TEA: 10 mmol/l) on secretion by the acinar (caerulein stimulated) and ductal (secretin stimulated) epithelia of the perfused rat pancreas. Within 10 min, ouabain caused a 79% inhibition of acinar secretion which was resolvable into two exponentials with half-times, respectively, of 0.24 min +/- 0.19 (S.D.) and 6.40 +/- 0.46 min. In contrast, it caused only a monoexponential inhibition of ductal secretion (61% in 10 min) with a half-time of 5.08 +/- 0.26 min. Ba caused a monoexponential inhibition of acinar secretion (70% in 10 min) with a half-time of 1.82 +/- 0.27 min, but it had no inhibitory effect on ductal secretion. The action of TEA was similar to that of Ba: it caused monoexponential inhibition of acinar secretion (26% in 10 min) with a half-time of 1.82 +/- 0.03 min, and it too had no effect on ductal secretion. For comparison, we also studied the effect of these drugs on the more rapidly secreting rat mandibular gland (stimulated with acetylcholine). All three drugs were strongly inhibitory: within 10 min, ouabain caused a 95%, Ba an 89% and TEA an 83% inhibition. The decay curves appeared to be monoexponential with half-times, respectively, of 1.49 +/- 0.12, 0.51 +/- 0.3 and 0.56 +/- 0.02 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Patient requests: correlates and therapeutic implications for Hispanic, black, and Caucasian patients

A patient's reason for coming to a psychiatric outpatient clinic (his/her request for service) should be the focal point as a therapist develops an appropriate therapeutic plan for that patient. Data have been collected on 173 Hispanic, Black and Caucasian patients with regard to their reasons for coming to the clinic and selected demographic and process/outcome variables. A factor analysis of the patient request data generated three conceptual factors, which account for 13 reasons for coming to the clinic. The relationship of these factors with selected demographic and therapy outcome variables was tested statistically, and implications for therapy with low income and minority patients are discussed.

Advances in controlling hypertension in low-income patients

Since hypertension is the foremost problem in minority and low-income populations treated in our community health centers, in 1976 we introduced a protocol that standardized diagnostic criteria and a step-care approach to the treatment of hypertension. In 1980, we modified the original protocol with guidelines for dietary management and an outline for improving physician-patient communication and health education. We hypothesized that implementing the protocol (and later modifications) would be associated with improved identification and control of hypertension. We conducted a cross-sectional study of hypertensive patients' charts in three community health centers in 1973, 1978, and 1982, and determined the status of blood pressure (BP) control of those patients by the end of the year. In 1973 (before protocol), 4 percent of hypertensives were undiagnosed and untreated, and 20 percent were lost to follow-up. Among those who remained under care, only 33 percent were under control (BP less than 160/95 mm Hg). In 1978, two years after the protocol was introduced, there were fewer undiagnosed and untreated patients (2 percent), but the number lost to follow-up increased to 31 percent. The proportion of hypertensives under control increased to 70 percent. In 1982, two years after the modifications to the protocol were introduced, the proportion of patients lost to follow-up decreased to 28 percent, and the proportion of patients with controlled blood pressure increased to 79 percent. The improved level of control was statistically significant at p less than .0001 (chi-square test).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of the HSV-2 early AG-4 antigen

Genital herpes simplex virus type 2 (HSV-2) infections can be distinguished from present or past HSV-1 infections by an AG-4 antigen complement fixation assay. The assay which utilizes a 4 hour HSV-2 infected cell extract prepared at a multiplicity of infection (MOI) of 1.0 PFU/cell, appears to consist of several viral proteins. Studies using monoclonal antibodies, polyclonal rabbit hyperimmune serum, HSV-1 X HSV-2 intertypic recombinant viruses and polyacrylamide gel electrophoresis suggest that ICP 8 may be one of the major antigens involved in the complement fixing reaction. It is probable that the success of the assay is not due to a true type specificity but rather a threshold phenomenon in which HSV-2 extracts contain more early viral antigens (including ICP 8) and sera from HSV-2 patients contain more complement fixing antibody to these antigens.

Self-reported psychiatric symptoms among black, Hispanic, and white outpatients

Examined ethnic differences among black, Hispanic, and white applicants for outpatient psychotherapy, using symptoms self-reported on the Symptom Checklist 90-Revised (SCL 90-R). The relationship between self-reported severity of symptoms and therapist-reported severity of psychiatric diagnoses also was examined in order to assess the utility of SCL 90-R as a predictor of diagnostic severity for these ethnic groups. One hundred sixty-five patients completed the SCL 90-R. The patients were predominantly in the low-income social classes. A significant ethnic effect was found on several symptom dimensions, with black patients less likely to report symptoms than Hispanic or white patients. Hispanic patients were found to report the highest symptom levels on 8 of 11 measures. While, overall, therapist diagnostic severity was related significantly to self-reported symptomatology, the relationship was strongest for white patients, significant but less strong for Hispanic patients, and not significant for black patients.

Orienting therapists about patients' needs to increase patient satisfaction

Twenty-nine psychotherapists received orientation about patients' cultural background, expectations, and therapeutic needs. They treated 98 patients before orientation and 73 afterward, and a follow-up interview was conducted 4-6 weeks after completion of therapy. The patients seen after therapist orientation were more satisfied with the services, felt better able to handle problems, were more likely to seek therapy for future problems, and felt more strongly that their needs for clinic services had been met than the patients seen by therapists before orientation. Analyses of therapist experience, patients' ethnicity, and patients' orientation to psychotherapy showed no significant interactions with patient satisfaction.

Orienting psychotherapists to better serve low income and minority patients

As a part of a larger NIMH study, 29 psychotherapists who were beginning training at a large urban psychiatric outpatient clinic participated in a special orientation program. The orientation program had the following objectives: First, to increase the therapists' knowledge about low income and minority patients; second, to increase the therapists' sensitivity to minority patients' requests and problems; and, third, to increase the effectiveness of the therapeutic encounter. The majority of therapists acted as their own controls; they saw patients before and then after participating in the orientation program. Data indicated that therapists improved significantly in knowledge, sensitivity, and effectiveness as a result of the special therapist orientation program.

Preparing low-income hispanic, black, and white patients for psychotherapy: evaluation of a new orientation program

Examined the effectiveness of a new orientation program designed to prepare low-income white and ethnic minority outpatients for psychotherapy. Sixty-two Hispanic, 51 black, and 60 white psychiatric outpatients in a large public psychiatric clinic participated prior to their first psychotherapy interview. Patients were presented with one of two experimental conditions; the oriented patients saw an audiovisual program that instructed them about psychotherapy, and the control patients saw a program that was neutral with regard to psychotherapy. The patients' knowledge and attitudes toward psychotherapy were assessed with two questionnaires. Results indicated that patients who were oriented were more knowledgeable about psychotherapy and more positive in their attitudes toward psychotherapy than were patients who had not been oriented. The role and utility of brief orientation programs for low-income and ethnic minority outpatients in public mental health facilities are discussed.

Compliance with chemotherapy: theoretical basis and intervention design

An experimental chemotherapy compliance enhancement program has been developed based on theory and findings from social psychology and learning theory. The essential ingredients are individualized instruction, behavior shaping and enhancement of social and environmental supports. The differential effects of these interventions upon compliance, as measured both by patient self-reports and by objective pharmacokinetic assays, are being tested.