Prevalence of violence victimization among patients seen in an urban public hospital walk-in clinic

OBJECTIVES

To study the prevalence of serious physical interpersonal violence and to identify the types of perpetrators, the frequency of occurrence, the time since the violence occurred, the risk profiles, and other factors related to victimization.

METHODS

One-week survey of all consecutively registered patients and their visitors in an urban public hospital adult walk-in clinic, using an anonymous self-administered questionnaire.

RESULTS

Of the 1,504 patients, 1,041 (69.2%) completed the questionnaire. The reported experience of serious physical violence victimization for the whole study population, both patients (n = 1,041) and visitors (n = 155), was 47.9% (573/1,196). A violence victim was more likely to be male [odds ratio (OR) = 1.41, 95% confidence interval (CI): 1.11, 1.78], African-American (OR = 1.27, 95% CI: 0.98, 1.63), aged 45 years or younger (OR = 1.55, 95% CI: 1.19, 2.03), and single (OR = 1.47, 95% CI: 1.16, 1.86). Alcohol use and drug use were clearly associated with violence victimization, with prevalence ORs of 2.26 (95% CI: 1.80, 2.85) for alcohol and 3.68 (95% CI: 2.66, 5.09) for drugs.

CONCLUSION

A history of serious physical violence victimization is common in inner-city hospital walk-in clinic patients. Walk-in clinics in urban areas of high violence, therefore, may prove to be important places for intervention and prevention of violence.

Imaging of individual normal and regenerating optic fibers in the brain of living adult goldfish

Retinal arbors in the tectum of living adult goldfish were imaged to determine whether the structural remodelling and refinement that occurs during development continues in adulthood. Individual optic fibers were labelled by making small injections of the lipophilic fluorescent dye DiI into ventral retina and viewing the exposed tectum through a fluorescence microscope equipped with a cooled CCD camera. Arbors were imaged in the living fish every 30-60 minutes for up to 7 hours. Normal adult goldfish showed no evidence of arbor remodelling during this period, though dynamic movements of varicosities present along axon segments were observed. For comparison, regenerating optic fibers were similarly imaged in fish that had undergone optic nerve crush 2-6 weeks previously. In these fish, dynamic structural changes were seen, including branch remodelling, extension and retraction of growth cones, and movement of varicosities.

Community-based perinatal care for disadvantaged adolescents: evaluation of The Resource Mothers Program

This study compared the effects of a community-based lay home visiting initiative for pregnant adolescents, the Norfolk Resource Mothers Program, with the effects of a more traditional clinic-based program. The Resource Mothers Program (RMP) supports disadvantaged teens through the use of para-professional home visitors who are similar to the teens in race and socio-economic status. In addition to recruiting teens into the program and encouraging early prenatal care, the Resource Mothers Program provides teen mothers and their families with practical help and increases community awareness regarding infant mortality and adolescent pregnancy. When compared with a traditional clinic-based multi-disciplinary program (MDP) using health professionals, the Resource Mothers Program reached a higher percentage of high-risk adolescents (e.g., 75.5% RMP vs. 45.6% MDP clients aged 17 years old or under), promoted a higher level of prenatal care (e.g., 53.1% RMP vs. 32.6% MDP clients beginning prenatal care before the fourth month of pregnancy), and resulted in pregnancy outcomes that favored the MDP but were comparable (e.g., 89.8% RMP vs. 93.5% MDP client babies were over 2500 grams at birth).

Further characterization of an amsacrine-resistant line of HL-60 human leukemia cells and its topoisomerase II. Effects of ATP concentration, anion concentration, and the three-dimensional structure of the DNA target

The characterization of type II topoisomerases from amsacrine-sensitive (HL-60) and amsacrine-resistant (HL-60/AMSA) human leukemia cells was extended. The intercalator resistance and etoposide sensitivity of the HL-60/AMSA cells themselves were confirmed, and the stability of this pharmacologic phenotype over many hundreds of cell generations was demonstrated. Prolonging exposure of HL-60/AMSA cells to amsacrine did not alter their sensitivity relative to that of HL-60 cells. Improved methods of immunoblotting allowed clear demonstration that the topoisomerase II within these cells exhibited sensitivity and resistance characteristics that mirrored those of the cells and the isolated enzymes themselves. Additional biochemical characterization of the type II topoisomerases indicated that both enzymes relaxed supercoiled DNA in a distributive fashion and that the ATP concentrations at which optimal catalytic activity of the two enzymes was exhibited were identical. The enzymes differed, however, in their activity optima in buffers of various type and ionic strength. Furthermore, the inability of the HL-60/AMSA enzyme to exhibit enhanced DNA cleavage in the presence of amsacrine could be overcome if the DNA target molecule contained a bend cloned into its polylinker region. By contrast, a bend in a DNA plasmid containing no polylinker was resistant to amsacrine-enhanced cleavage in the presence of HL-60/AMSA topoisomerase II, as was a plasmid containing a polylinker with no bend. This suggests that an unusual DNA conformation (a bend) in a specific DNA context (a polylinker) may be a favored site for topoisomerase II action. It also suggests a mechanism by which the sites and extent of topoisomerase II activity can be controlled in cells.

Temporal profile and significance of metabolic failure and trophic changes in the canine cerebral arteries during chronic vasospasm after subarachnoid hemorrhage

To investigate the pathogenetic significance of metabolic failure observed in spastic cerebral arteries after subarachnoid hemorrhage (SAH), the temporal profile of alterations in the arterial content of high-energy phosphates was studied. A canine model of double hemorrhage was used. Constriction of the basilar artery was measured angiographically on Days 3, 5, 7, and 14 after SAH in separate groups of animals. Adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), guanosine triphosphate (GTP), guanosine diphosphate, creatine phosphate (CrP), and creatine (Cr) levels in the arteries were assayed using high-performance liquid chromatography. A time-dependent development of angiographic spasm was confirmed. A mild vasospasm was seen in the group studied 3 days after SAH, progressed in the Day 5 group, remained comparably severe in the Day 7 group, and resolved partially in the Day 14 group. The content of high-energy phosphates (ATP, GTP, and CrP) declined rapidly over the course of the study, and a significant reduction in ATP, GTP, and CrP was observed in the Day 3 group. Levels of ATP and CrP decreased further in the Day 5 and 7 groups. The decrement in GTP was completed in the early phase; a significant reduction took place in the Day 3 group, with no progression thereafter and no recovery through Day 14. Total adenylate (ATP + ADP + AMP) and total creatine (Cr + CrP) content diminished markedly over the course of the study. These results indicate that metabolic failure and trophic disturbance in the cerebral artery occurs with a rapid onset following SAH and progresses in close association with the development of vasospasm, suggesting a significant causal relationship with the pathogenesis.

Polarized secretion of thrombospondin is opposite to thyroglobulin in thyroid epithelial cells

In addition to thyroglobulin, primary thyrocytes secrete into the culture medium significant quantities of p500, a protein so named because of its M(r) > or = 500,000. Epithelial monolayers cultured on porous filters serve as a useful model system in which to study protein secretion. From these monolayers, thyroglobulin, the precursor in thyroid hormonogenesis, was released with apical predominance, while p500 was found mostly in the basolateral medium. Thyrocyte exposure to thyrotropin augmented selectively thyroglobulin but not p500 production. By contrast, exposure to cycloheximide actually augmented p500 production, a response observed for immediate-early proto-oncogenes. Using thyrocyte conditioned medium, the p500 protein was purified to homogeneity. Peptide sequencing of tryptic fragments of purified p500 showed identity to thrombospondin. Immunoprecipitation of thrombospondin from media bathing primary thyrocytes and the FRTL5 cell line quantitatively recovered p500, confirming its identity and indicating an epithelial origin. Gel filtration of secreted thrombospondin eluted at a high molecular weight, suggesting complexation with components of the extracellular matrix. Further, immunofluorescence showed cellular codistribution of thrombospondin and thyroglobulin, although thrombospondin exhibited predominantly an extracellular, basolateral deposition. It seems likely that thrombospondin production by thyrocytes plays a role in the growth or development of the thyroid epithelium.

High-energy phosphate levels in the cerebral artery during chronic vasospasm after subarachnoid hemorrhage

High-energy phosphate levels were measured in the canine cerebral artery during chronic vasospasm. Subarachnoid hemorrhage and vasospasm were induced by percutaneous injections of autologous venous blood into the cisterna magna. Narrowing of the artery was confirmed by angiography 7 days later. Levels of adenosine phosphates (adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP)), guanosine phosphates (guanosine triphosphate (GTP) and guanosine diphosphate (GDP)), and creatine phosphate (CrP) in the basilar artery were quantified using high-performance liquid chromatography. The total creatine (Crtotal) content was measured by a spectrophotometric method after acid hydrolysis of CrP. Levels of ATP, GTP, and CrP were markedly reduced in the spastic arteries, and ratios of ATP:ADP, GTP:GDP, and CrP:Crtotal were significantly decreased. The results indicate a serious disturbance in the energy metabolism that takes place in the cerebral artery during chronic vasospasm.

Dietary omega-3 fatty acids and endothelium-dependent responses in porcine cerebral arteries

PURPOSE

We sought to determine the effect of dietary omega-3 polyunsaturated fatty acids on cerebrovascular endothelium-dependent responses in studies performed on isolated porcine basilar arteries.

METHODS

Male Yorkshire pigs (6-8 weeks old) were kept for 4 weeks on a standard diet (control group, n = 12) or on chow supplemented with polyunsaturated fatty acids (eicosapentaenoic acid, 3.5 g/day, or docosahexaenoic acid, 1.5 g/day; treated group, n = 12). Isometric tension recording of the basilar artery was carried out and responses were compared between the two groups.

RESULTS

The regimen resulted in a decrease in the plasma arachidonic acid level and an increase in eicosapentaenoic acid. Endothelium-dependent relaxations induced by bradykinin and adenosine diphosphate were augmented in the basilar arteries of the treated group. Incubation with indomethacin (10(-5) M) prevented the augmentation of the relaxations induced by bradykinin, but not those caused by adenosine diphosphate. The indomethacin-sensitive, endothelium-dependent contractions to arachidonic acid remained comparable in the two groups, indicating that the activity of cyclooxygenase was not affected by the diet.

CONCLUSIONS

Dietary supplementation with omega-3 polyunsaturated fatty acids enhances endothelium-dependent relaxations in the basilar artery by two mechanisms: 1) replacement of endogenous arachidonic acid and suppression of the concomitant release of vasoconstrictor prostaglandins from the endothelium, and 2) enhancement of the release of endothelium-derived relaxing factor.

Reduced production of cGMP underlies the loss of endothelium-dependent relaxations in the canine basilar artery after subarachnoid hemorrhage

Endothelium-dependent relaxations are inhibited during chronic vasospasm after subarachnoid hemorrhage in the canine basilar artery, although the luminal release of endothelium-derived relaxing factor (EDRF) is maintained. The present study investigated the mechanisms underlying the impaired vascular reactivity and in particular whether the loss of responsiveness of the smooth muscle to EDRF is due to an impaired production of cGMP. Bradykinin and nitric oxide evoked concentration-dependent relaxations in isolated canine basilar arteries with and without endothelium, respectively, which were reduced in the subarachnoid hemorrhage group. Relaxations evoked by M&B22,948 (an inhibitor of cGMP phosphodiesterases) were smaller, but those evoked by the lipophilic cGMP analogue 8-bromo-cGMP were potentiated slightly in the subarachnoid hemorrhage group. The resting levels of cGMP in rings with endothelium (reflecting the effect of spontaneous release of EDRF) and those evoked by bradykinin in rings with endothelium and by nitric oxide in rings without endothelium were diminished in the subarachnoid hemorrhage group. These data indicate that the altered endothelium-mediated relaxations of the smooth muscle after subarachnoid hemorrhage is due, at least in part, to an impaired activation of soluble guanylate cyclase leading to a reduced production of cGMP in the smooth muscle.

Endothelium-dependent relaxations and chronic vasospasm after subarachnoid hemorrhage

Endothelium-dependent relaxations are abolished in the canine basilar artery after subarachnoid hemorrhage. However, the release of endothelium-derived relaxing factor (EDRF) toward the lumen is not reduced. These findings suggest that the responsiveness of the smooth muscle to EDRF is impaired during chronic vasospasm after subarachnoid hemorrhage.

Surgery of spinal nerve schwannoma. Risk of neurological deficit after resection of involved root

When surgically removing a spinal nerve schwannoma, preservation of the involved root is attempted and may be feasible. However, in large tumors, sacrifice of the nerve root is often required to achieve total removal of the tumor, and the resection does not always result in postoperative neurological deficit. The present study was designed to determine the incidence and extent of neurological deficit as correlated with resection of the root, performed between 1976 and 1987 in 86 cases at the time of total removal of spinal schwannoma. Thirty-one patients underwent sacrifice of a root critical for the function of the upper (C5-T1, 14 cases) or the lower extremities (L3-S1, 17 cases). This report is limited to these 31 cases. Only seven patients (23%) developed detachable motor or sensory deficits postoperatively. All deficits were no more than partial loss of strength or sensation. Fifteen of the 31 patients had large tumors with extradural components, which necessitated sacrifice of the entire motor and sensory radix; however, 11 (76%) of these 15 did not develop any deficits referrable to the involved myotome or dermatome. Six cases showed histological characteristics of "neurofibroma," with axons intermingled in the tumor, and none developed a postoperative deficit. Preoperative electromyography was performed in 23 cases. Of 13 patients with findings of denervation, five developed deficits after surgery; the other 10 patients showed no evidence of denervation, and none had deficits after surgery. These results indicate that the spinal roots giving origin to schwannoma are frequently nonfunctional at the time of surgery, and risks of causing disabling neurological deficit after sacrificing these roots are small.

Alterations of mechanical properties in canine basilar arteries after subarachnoid hemorrhage

The purpose of this study was to examine the hypotheses that structural stiffening of the arterial wall contributes to chronic cerebral vasospasm, and that alteration in properties of smooth muscle takes place after subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage and subsequent chronic vasospasm were induced in dogs by two cisternal injections of autologous blood (on Day 0 and Day 2). Vasospasm was confirmed by angiography performed on Day 0 and Day 7. Animals in the control group underwent angiography only. On Day 8, the mechanical properties of the basilar arteries were studied in vitro. Passive compliance, measured under total inhibition of spontaneous myogenic tone with diltiazem (10(-4) M) plus papaverine (10(-4) M) was smaller in the SAH group. The length-contraction curve was shifted to the left and the optimum length for maximum contraction (Lmax) was significantly shorter in the spastic blood vessels. The spontaneous myogenic tone was augmented in the SAH group, resulting in an increase in resting tension at each length. By contrast, the maximum contractions in response to KCl and uridine 5'-triphosphate were markedly reduced in the SAH group, without changes in sensitivity to these agents. These differences in mechanical properties were observed in rings both with and without endothelium. The results indicate that, in chronic vasospasm, stiffening of the noncontractile component of the vasculature takes place as well as alterations in the contractile component, both of which presumably contribute to the shift in resting length-tension relationship and length-contraction relationship of the artery. The decreased distensibility, the increase in resting tension, and the shortening of the Lmax all favor a smaller diameter of the artery after SAH, possibly contributing to vasospasm.

Monocyte/macrophage procoagulant activity as a measure of immune responsiveness in Lewis and brown Norway inbred rats. Discordance with lymphocyte proliferative assays

In vitro lymphocyte proliferative assays were performed using Lewis (Lew) and Brown Norway (BN) rats, and compared to induction of monocyte/macrophage procoagulant activity (PCA) in a mixed lymphocyte culture and by endotoxin (LPS) (E. Coli 0111:B4). Splenic mononuclear cells from Lew rats had significantly greater mitogen-induced proliferation to concanavalin A (P = .002) and phytohemagglutinin (P = 0.007). The Lew cells also showed greater allogeneically induced proliferation by BN cells in a one-way MLC in comparison to the reciprocal BN proliferative response (P less than 0.04). PCA induction in peripheral blood mononuclear cells (PBM) by allogeneic stimulation in MLC or total content PCA by LPS did not vary significantly between the 2 strains (P greater than 0.5). Induction of PCA by LPS was rapid, with a moderate rise over basal activity at 3 hr and maximal activity at 6 hr. Two-way allogeneic induction of PCA in PBM from BN and Lew rats resulted in PCA elevation by 3 hr, which became maximal at 18 hr. One-way MLC with Lew or BN cells as responders resulted in moderate increases in PCA by 3-6 hr, with equivalent maximal activities recorded at 18 hr. Viable PCA accounted for 26-32% of total content PCA in both Lew and BN rats. Maximal allogeneic PCA induction by MLC was 14-18% of PCA induced by LPS and required a longer incubation for its expression. Our results indicate that in vitro PCA expression by Lew and BN PBM following allogeneic or endotoxin stimulation shows little interstrain variability in comparison to lymphocyte proliferative responses. Thus PCA appears to more closely reflect the observed in vivo responses of these strains to allogeneic challenge.

Release of endothelium-derived relaxing factor after subarachnoid hemorrhage

The purpose of this study was to determine the cause of the loss of endothelium-dependent relaxation observed in chronic cerebral vasospasm. A bioassay system was developed to measure the release of endothelium-derived relaxing factor (EDRF) from canine basilar arteries. Subarachnoid hemorrhage (SAH) was induced in dogs by two injections of autologous blood into the cisterna magna. Angiograms were performed on the 7th day after SAH to check the presence of chronic vasospasm. The animals were sacrificed on the 8th day, and in vitro experiments were performed on rings harvested from the basilar artery. These confirmed loss of endothelium-dependent relaxation in response to bradykinin and arginine vasopressin in the group with SAH. The basilar arteries were perfused with modified Krebs-Ringer solution. The perfusate was bioassayed with a ring of coronary artery without endothelium (bioassay ring). The release of the EDRF was detected by relaxation of the bioassay ring contracted with prostaglandin F2 alpha. Arginine vasopressin and bradykinin added to the perfusate upstream of the basilar artery caused concentration-dependent release of the EDRF. The direct effect of these peptides on the smooth muscle of the bioassay ring was to cause contraction. The release of the EDRF was identical in basilar arteries from the control and the SAH groups. These results indicate that the release of the EDRF is not impaired during chronic vasospasm, and thus that the loss of the endothelium-dependent relaxation is due to a decreased transfer of the EDRF or a reduced responsiveness of the smooth muscle to the factor.

Systemic lipopolysaccharide and pokeweed mitogen increase quinolinic acid content of mouse cerebral cortex

The effects of lipopolysaccharide and pokeweed mitogen on brain L-tryptophan and quinolinic acid (QUIN) concentrations were investigated in C57BL/6NCR mice. Twenty-four hours after an intraperitoneal injection of lipopolysaccharide (5 micrograms from Salmonella abortus equii) or pokeweed mitogen (500 micrograms), cortical QUIN concentrations were increased by 81 +/- 6% and 182 +/- 15%, respectively. Plasma QUIN was increased 175 +/- 7% of control in pokeweed-mitogen treated mice only. Brain L-tryptophan concentrations were increased, whereas plasma L-tryptophan concentrations were decreased. The consequences of increased QUIN concentrations during endotoxin and mitogen exposure remain to be determined.

Endothelium-dependent relaxation to aggregating platelets in isolated basilar arteries of control and hypercholesterolemic pigs

The role of the endothelium was examined in the response to aggregating platelets in cerebral arteries from normal and hypercholesterolemic animals. Male Yorkshire pigs were fed either a normal diet or a 2% high-cholesterol diet for 10 weeks. Endothelium-dependent responses were examined in vitro. In rings of basilar arteries from control animals aggregating platelets caused endothelium-dependent relaxations, which were significantly inhibited by apyrase, an adenosine diphosphatase and triphosphatase, but were augmented by methiothepin, a combined S1- and S2-serotonergic blocker. In quiescent rings platelets induced contractions that were inhibited by the presence of the endothelium; these contractions were significantly inhibited by methiothepin, but not by ketanserin (an S2-serotonergic blocker) or dazoxiben (a thromboxane-synthetase blocker) in the presence or absence of SQ29548 (a thromboxane-receptor blocker). Adenosine diphosphate but not serotonin caused endothelium-dependent relaxations. In cholesterol-fed animals the endothelium-dependent relaxations in response to aggregating platelets and adenosine diphosphate were impaired. These experiments indicate that 1) the endothelium inhibits the vasoconstrictor effect of aggregating platelets in porcine cerebral arteries; 2) platelet-induced relaxations are achieved mainly by a purinergic mechanism, while platelet-induced contractions are mediated by activation of S1-serotonergic receptors with little contribution of thromboxanes; and 3) hypercholesterolemia impairs the endothelium-dependent relaxations in response to aggregating platelets due to the impaired responses to adenosine diphosphate.

Alterations in endothelium-dependent responsiveness of the canine basilar artery subarachnoid hemorrhage

To investigate the alteration of endothelium-dependent responses in chronic vasospasm after subarachnoid hemorrhage (SAH), experiments were carried out in the double-hemorrhage canine model. After the presence of vasospasm was confirmed by cerebral angiography on Days 0 and 7, pharmacological studies on the basilar artery were conducted in vitro on Day 8. In the SAH group, endothelium-dependent relaxation was abolished in response to arginine vasopressin and was significantly reduced in response to thrombin. Endothelium-independent relaxation in the SAH group was preserved in response to papaverine and was minimally reduced in response to sodium nitroprusside. Endothelium-dependent contraction in response to arachidonic acid, acetylcholine, the calcium ionophore A23187, adenosine diphosphate, mechanical stretching, and hypoxia persisted in the SAH group. The maximal contraction to KCl and uridine triphosphate, which is endothelium-independent, was diminished in the SAH group, but not changes in sensitivity were noted in the concentration-response relationships. A significant correlation was observed between the degree of vasospasm determined angiographically and the loss of endothelium-dependent relaxation. The loss of endothelium-dependent relaxation and the persistence of endothelium-dependent contraction suggest that the deterioration in the endothelium-dependent responses may be an important component in the pathogenesis of cerebral vasospasm.