Scavenger receptors, oxidized LDL, and atherosclerosis

Oxidized LDL (OxLDL) competes with oxidatively damaged and apoptotic cells for binding to mouse peritoneal macrophages, implying the presence of one or more common domains. However, the nature of the ligands involved has not been determined. Studies in this laboratory over the last several years provide evidence that oxidized phospholipids, present in OxLDL and also in the membrane of apoptotic cells, represent one such ligand. These oxidized phospholipids, either in the lipid phase of OxLDL or becoming attached covalently to apoprotein B during LDL oxidation, have been shown to play a major role in the binding of OxLDL to CD36 and to SR-B1 expressed in transfected cells. The lipid and protein moieties compete with each other to some extent, indicating that they are binding to at least one common site. A monoclonal antibody selected because of its reactivity with OxLDL proved to be an antibody against oxidized phospholipids (but not native phospholipids). This antibody (EO6) blocked the uptake of OxLDL by CD36 and by SR-B1 in transfected cells by as much as 80%; it also inhibited macrophage phagocytosis of apoptotic cells by about 40%. Thus, the persistence of receptors for OxLDL during evolution is probably accounted for by their role in recognition of ligands on the surfaces of oxidatively damaged or apoptotic cells. This has important implications in biology generally and specifically in atherogenesis, because apoptosis is a prominent feature of late lesions.

Human-derived anti-oxidized LDL autoantibody blocks uptake of oxidized LDL by macrophages and localizes to atherosclerotic lesions in vivo

Autoantibodies to oxidation-specific epitopes of low density lipoprotein (LDL), such as malondialdehyde-modified LDL (MDA-LDL), occur in plasma and atherosclerotic lesions of humans and animals. Plasma titers of such antibodies are correlated with atherosclerosis in murine models, and several such autoantibodies have been cloned. However, human-derived monoclonal antibodies to epitopes of oxidized LDL (OxLDL) have not yet been reported. We constructed a phage display antibody library from a patient with high plasma anti-MDA-LDL titers and isolated 3 monoclonal IgG Fab antibodies, which specifically bound to MDA-LDL. One of these, IK17, also bound to intact OxLDL as well as to its lipid and protein moieties but not to those of native LDL. IK17 inhibited the uptake of OxLDL by macrophages and also bound to apoptotic cells and inhibited their phagocytosis by macrophages. IK17 strongly immunostained necrotic cores of human and rabbit atherosclerotic lesions. When (125)I-IK17 was injected intravenously into LDL receptor-deficient mice, its specific uptake was greatly enriched in atherosclerotic plaques versus normal aortic tissue. Human autoantibodies to OxLDL have important biological properties that could influence the natural course of atherogenesis.

Renal biopsy in elderly patients: clinicopathological correlation in 117 Korean patients

AIM

In the elderly with renal disease, the clinical presentations are frequently inconsistent with the pathologic findings. We tried to clarify the differences in pathological findings between the young and the elderly, in Korea and in Western countries, and the usefulness of a percutaneous renal biopsy in the elderly with renal disease.

PATIENTS AND METHODS

We analyzed the clinical presentations and spectrums of renal histopathology by reviewing medical records and renal biopsy reports retrospectively in 117 Korean patients aged 60 years or more with renal disease.

RESULTS

85 patients had primary renal disease. The remaining 32 patients had renal diseases associated with systemic conditions. Out of the 85 patients with primary renal disease, 61 cases presented as idiopathic nephrotic syndrome. Compared with renal biopsy results of younger adult patients (age 15-59, n = 1,908), membranous nephropathy, crescentic glomerulonephritis, membranoproliferative glomerulonephritis, amyloidosis, light chain disease, and thrombotic thrombocytopenic purpura were more prevalent, but IgA nephropathy and lupus nephritis were less common in the elderly patients. In clinical presentation, nephrotic syndrome and rapidly progressive renal failure were more prevalent, but asymptomatic urinary abnormality was less common in elderly patients. The responsiveness to treatment was good in elderly patients with minimal-change lesion (complete remission in all patients) but poor in crescentic glomerulonephritis, IgA nephropathy, and membranoproliferative glomerulonephritis. From the above findings, the clinical presentation, patterns of histopathology and responsiveness to treatment of elderly Korean patients were similar to those of the younger Korean control group and the Western elderly group.

CONCLUSION

Percutaneous renal biopsy is a useful diagnostic aid and can be used as a therapeutic guideline even in elderly patients with renal disease.

12/15-lipoxygenase translocation enhances site-specific actin polymerization in macrophages phagocytosing apoptotic cells

The enzyme 12/15-lipoxygenase (12/15-LO) introduces peroxyl groups in a position-specific manner into unsaturated fatty acids in certain cells, but the role of such enzymatic lipid peroxidation remains poorly defined. Here we report a novel function for 12/15-LO in mouse peritoneal macrophages. When macrophages were coincubated with apoptotic cells, the enzyme translocated from cytosol to the plasma membrane and was more extensively concentrated at sites where macrophages bound apoptotic cells, colocalizing with polymerized actin of emerging filopodia. Disruption of F-actin did not prevent the 12/15-LO translocation. In contrast, inhibition of the 12/15-LO activity, or utilization of genetically engineered macrophages in which the 12/15-LO gene has been disrupted, greatly reduced actin polymerization in phagocytosing macrophages. Lysates of 12/15-LO-deficient macrophages had significantly lower ability to promote in vitro actin polymerization than the lysates of wild type macrophages. These studies suggest that the 12/15-LO enzyme plays a major role in local control of actin polymerization in macrophages in response to interaction with apoptotic cells.

Oxidized LDL reduces monocyte CCR2 expression through pathways involving peroxisome proliferator-activated receptor gamma

The CCR2-mediated recruitment of monocytes into the vessel wall plays an important role in all stages of atherosclerosis. In recent studies, we have shown that lipoproteins can modulate CCR2 expression and have identified native LDL as a positive regulator. In contrast, oxidized LDL (OxLDL), which is mainly formed in the aortic intima, reduces CCR2 expression, promotes monocyte retention, and may cause pathological accumulation of monocytes in the vessel wall. We now provide evidence that OxLDL reduces monocyte CCR2 expression by activating intracellular signaling pathways that may involve peroxisome proliferator-activated receptor gamma (PPARgamma). Receptor-mediated uptake of the lipoprotein particle was required and allows for delivery of the exogenous ligand to the nuclear receptor. The suppression of CCR2 expression by OxLDL was mediated by lipid components of OxLDL, such as the oxidized linoleic acid metabolites 9-HODE and 13-HODE, known activators of PPARgamma. Modified apoB had no such effect. Consistent with a participation of the PPARgamma signaling pathway, BRL49653 reduced CCR2 expression in freshly isolated human monocytes ex vivo and in circulating mouse monocytes in vivo. These results implicate PPARgamma in the inhibition of CCR2 gene expression by oxidized lipids, which may help retain monocytes at sites of inflammation, such as the atherosclerotic lesion.

Natural antibodies with the T15 idiotype may act in atherosclerosis, apoptotic clearance, and protective immunity

The immune response to oxidized LDL (OxLDL) may play an important role in atherogenesis. Working with apoE-deficient mice, we isolated a panel of OxLDL-specific B-cell lines that secrete IgM Abs that specifically bind to oxidized phospholipids such as 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphorylcholine (POVPC). These Abs block uptake of OxLDL by macrophages, recognize similar oxidation-specific epitopes on apoptotic cells, and are deposited in atherosclerotic lesions. The Abs were found to be structurally and functionally identical to classic "natural" T15 anti-PC Abs that are of B-1 cell origin and are reported to provide optimal protection from virulent pneumococcal infection. These findings suggest that there has been natural selection for B-1 cells secreting oxidation-specific/T15 antibodies, both for their role in natural immune defense and for housekeeping roles against oxidation-dependent neodeterminants in health and disease.

Natural antibodies with the T15 idiotype may act in atherosclerosis, apoptotic clearance, and protective immunity

The immune response to oxidized LDL (OxLDL) may play an important role in atherogenesis. Working with apoE-deficient mice, we isolated a panel of OxLDL-specific B-cell lines that secrete IgM Abs that specifically bind to oxidized phospholipids such as 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphorylcholine (POVPC). These Abs block uptake of OxLDL by macrophages, recognize similar oxidation-specific epitopes on apoptotic cells, and are deposited in atherosclerotic lesions. The Abs were found to be structurally and functionally identical to classic "natural" T15 anti-PC Abs that are of B-1 cell origin and are reported to provide optimal protection from virulent pneumococcal infection. These findings suggest that there has been natural selection for B-1 cells secreting oxidation-specific/T15 antibodies, both for their role in natural immune defense and for housekeeping roles against oxidation-dependent neodeterminants in health and disease.

Immunological responses to oxidized LDL

Considerable evidence now points to an important role for the immune system in experimental models of atherosclerosis. We have reviewed the growing body of evidence that oxidation of LDL generates a wide variety of neoself determinants that lead to cellular and humoral immune responses. In particular, we have demonstrated that at least some of the oxidation-specific epitopes generated on the oxidized LDL particle, such as oxidized phospholipid epitopes, are also generated on apoptotic cells and are also present on the surface of some bacteria. Many of these same epitopes serve as important ligands mediating the binding and clearance of oxidatively damaged lipoprotein particles and apoptotic cells, and the innate immune response to these epitopes can be seen as a concerted response to effect their removal. In addition, other epitopes of OxLDL also undoubtedly play a role in the immune activation that characterizes the progressive atherosclerotic plaque. It will be of great importance to define the importance of the role of these responses and to understand which are beneficial and which deleterious. Such information could lead one day to novel therapeutic approaches to inhibit atherogenesis that take advantage of the ability to manipulate the immune response.

Comparison of behavior therapy methods for urinary incontinence following prostate surgery: a pilot study

Americans are living longer. As a result, an increased number of pathologic prostates are being detected and treated. As a consequence of complications from surgical treatment, such as prostatectomy, urinary incontinence may occur. However, it is important to understand urinary continence in the male and the anatomic changes that result with prostatectomy. Having objective measures that are cost-effective and accessible can assist with equaling subjective and objective assessments of continence, as well as determining successful outcomes and the need for more complex behavioral treatments.

Monoclonal antibodies against oxidized low-density lipoprotein bind to apoptotic cells and inhibit their phagocytosis by elicited macrophages: evidence that oxidation-specific epitopes mediate macrophage recognition

Apoptosis is recognized as important for normal cellular homeostasis in multicellular organisms. Although there have been great advances in our knowledge of the molecular events regulating apoptosis, much less is known about the receptors on phagocytes responsible for apoptotic cell recognition and phagocytosis or the ligands on apoptotic cells mediating such recognition. The observations that apoptotic cells are under increased oxidative stress and that oxidized low-density lipoprotein (OxLDL) competes with apoptotic cells for macrophage binding suggested the hypothesis that both OxLDL and apoptotic cells share oxidatively modified moieties on their surfaces that serve as ligands for macrophage recognition. To test this hypothesis, we used murine monoclonal autoantibodies that bind to oxidation-specific epitopes on OxLDL. In particular, antibodies EO6 and EO3 recognize oxidized phospholipids, including 1-palmitoyl 2-(5-oxovaleroyl) phosphatidylcholine (POVPC), and antibodies EO12 and EO14 recognize malondialdehyde-lysine, as in malondialdehyde-LDL. Using FACS analysis, we demonstrated that each of these EO antibodies bound to apoptotic cells but not to normal cells, whereas control IgM antibodies did not. Confocal microscopy demonstrated cell-surface expression of the oxidation-specific epitopes on apoptotic cells. Furthermore, each of these antibodies inhibited the phagocytosis of apoptotic cells by elicited peritoneal macrophages, as did OxLDL. In addition, an adduct of POVPC with BSA also effectively prevented phagocytosis. These data demonstrate that apoptotic cells express oxidation-specific epitopes-including oxidized phospholipids-on their cell surface, and that these serve as ligands for recognition and phagocytosis by elicited macrophages.

Mechanical properties of biodegradable polymers and composites proposed for internal fixation of bone

The mechanical properties of biodegradable polymers and composites proposed for use in internal fixation (in place of stainless steel) are crucial to the performance of devices made from them for support of healing bone. To assess the reported range of properties and degradation rates, we searched and reviewed papers and abstracts published in English from 1980 through 1988. Mechanical property data were found for poly(lactic acid), poly(glycolic acid), poly(epsilon-caprolactone), polydioxanone, poly(ortho ester), poly(ethylene oxide), and/or their copolymers. Reports of composites based on several of these materials, reinforced with nondegradable and degradable fibers, were also found. The largest group of studies involved poly(lactic acid). Mechanical test methods varied widely, and studies of the degradation of mechanical properties were performed under a variety of conditions, mostly in vitro rather than in vivo. Compared to annealed stainless steel, unreinforced biodegradable polymers were initially up to 36% as strong in tension and 54% in bending, but only about 3% as stiff in either test mode. With fiber reinforcement, reported highest initial strengths exceeded that of stainless steel. Stiffness reached 62% of stainless steel with nondegradable carbon fibers, 15% with degradable inorganic fibers, but only 5% with degradable polymeric fibers. The slowest-degrading unreinforced biodegradable polymers were poly(L-lactic acid) and poly(ortho ester). Biodegradable composites with carbon or inorganic fibers generally lost strength rapidly, with a slower loss of stiffness, suggesting the difficulty of fiber-matrix coupling in these systems. The strength of composites reinforced with (lower modulus) degradable polymeric fibers decreased more slowly. Low implant stiffness might be expected to allow too much bone motion for satisfactory healing. However, unreinforced or degradable polymeric fiber reinforced materials have been used successfully clinically. The key has been careful selection of applications, plus use of designs and fixation methods distinctly different from those appropriate for stainless steel devices.

Evaluation of absorbable poly(ortho esters) for use in surgical implants

Recent reports describe an unfavorable noninfective inflammatory response to acidic degradation products in clinical applications of bone fixation devices fabricated from bulk hydrolyzing polyglycolides and polylactides (PGA and PLA). The work described here suggests that poly(ortho esters) (POEs) offer an alternative. By comparison, hydrophobic POEs degrade predominately via surface hydrolysis, yielding first a combination of nonacidic degradation products, followed by alcoholic and acidic products gradually over time. POE specimens proved acutely nontoxic in United States Pharmacopeia tests of cellular, intracutaneous, systemic, and intramuscular implant toxicity. Hot-molded specimens degraded slowly in saline, retaining 92% initial stiffness (1.6 GPa flexion) and retaining 80% initial strength (66 MPa flexion) in 12 weeks. Degradation was almost unaffected by decreasing saline pH from 7.4 to 5.0. This demonstrated the relative hydrophobicity of POEs, since incorporation of small amounts of acid within the polymer markedly increases the degradation rate. Degradation rates were increased substantially by dynamic mechanical loading in saline. This may be true for other degradable polymers also, but no data could be found in the literature. Presumably, tensile loading opens microcracks, allowing water to enter. Solvent cast POE films were strong in tension (30 + MPa tensile yield) and reasonably tough (12-15% elongation to yield). Higher molecular weight films (41-67 kDa) showed no degradation in mechanical properties after 31 days in physiological buffer at body temperature. A 27-kDa film offered similar initial strength and stiffness but began showing mechanical degradation at 31 days. The films showed a decrease in weight with exposure time but no change in either molecular weight or water absorption at 31 days, further supporting the observation that POE degrades by surface hydrolysis rather than by bulk hydrolysis.

Arthroscopic microdiscectomy: comparison of preoperative and postoperative imaging studies

Forty-three patients with symptomatic lumbar disc herniations underwent paralumbar arthroscopic disc extraction by a uniportal or biportal approach and postoperative imaging studies. Thirty-one patients were subjected to immediate postoperative computed tomography (CT) at the operative site. The other 12 underwent magnetic resonance imaging (MRI at varying times postoperatively. Images obtained before and after surgery were magnified; the herniation area (H) and the spinal canal area (C) were measured by computerized digitization. The H/C ratio was calculated, and the percentage of canal clearance was obtained in each case. Immediate postoperative CT imaging in 16 of 18 patients with subligamentous and extraligamentous nonmigrated herniation showed a significant change in the external geometry of the annulus and canal clearance (75% to 100% canal clearance). Less compelling change in the postoperative CT images was unexpectedly seen with extraforaminal and foraminal herniations. This result may be attributable to limitations in our study methodology and not to inadequate decompression. Follow-up MRI on these patients within 8 weeks postoperatively did eventually show significant change in two cases that were initially not significant. This study confirms that the arthroscopic microdiscectomy technique effectively extracts herniated disc fragments and alters posterior annular contour, including removal of sequestered pieces.

Minimally invasive disc surgery. Nucleotomy versus fragmentectomy

There is continued debate as to the optimum surgical management of a herniated disc with sciatica. There are proponents of conventional microdiscectomy as well as those who advocate minimally invasive approaches, including central disc decompression or nucleotomy as well as arthroscopic lumbar microdiscectomy and fragmentectomy. In this controversy (I), Dr. Gary Onik takes the position that central disc decompression is both safe and efficacious and may be the procedure of choice for recurrent disc herniations (II). Dr. Parvis Kambin takes the opposing position and advocates arthroscopically assisted fragmentectomy as the procedure of choice.

Blood lactate threshold and type II fibre predominance in patients with exertional heatstroke

OBJECTIVES

Severe damage to skeletal muscle is usually seen in patients with exertional heatstroke. Thirty seven young military recruits with exertional heatstroke in Taiwan from 1992 to 1995 were studied to evaluate changes in muscle pathology and blood lactate with exercise.

METHODS

A biopsy sample of the vastus lateralis was taken from recruits within 10 days of the initial presentation. Results were compared with those from 15 controls matched for age and sex. During the recovery period, 90-150 days after exertional heatstroke, 29 patients participated in a constant work load test on the treadmill to assess their blood lactate threshold, and a second biopsy sample was taken. Each biopsy was examined histologically for pathology, distribution of fibre types, and fibre diameter.

RESULTS

Twenty four of the 37 patients with exertional heatstroke developed rhabdomyolysis and 18 of these had type II fibre predominance in their muscle biopsy. The patients with type II fibre predominance had a higher tendency to develop rhabdomyolysis (chi 2 = 6.84, P < 0.01). The time required to reach a blood lactate threshold during a constant treadmill work load after recovery was significantly shorter in the patients with exertional heatstroke who had type II fibre predominance (P < 0.01). There was a positive correlation between the highest value of blood lactate and the percentage of type II fibres in all tested subjects (r = 0.82, P < 0.01).

CONCLUSION

Patients with type II fibre predominance are more susceptible to exertional heatstroke and tend to have a higher blood lactate concentration and a shorter time to reach blood lactate threshold under a treadmill load test.

[Study on the stability of Japanese encephalitis vaccine--development of freeze-dry dosage form]

In order to prolong shelf-life and improve the quality of the vaccine product, not only an effective stabilizer but also a more proper dosage form has been sought. The stability of a Japanese encephalitis (JE) vaccine produced from mouse brain along with a variety of stabilizers and lyophilization protocols was evaluated. Without any stabilizers added, almost 90% of the antigenicity would vanish after freeze-drying process. Comparative studies of various compounds, including carbohydrates, amino acids, peptides and medium 199, on both antigenicity preservation and thermostability of the vaccine were carried out. The results indicated that the best reconstituted vaccines were prepared with two stabilizer formulations, sucrose and sucrose/gelatin. They were further examined by accelerated stability test at room and higher temperatures. The sucrose-added lyophilized vaccine can retain its original antigenicity for more than 60 days both at 37 degrees C and 45 degrees C. We conclude the thermostability efficiency of each of the stabilizers tested is as that follows: sucrose > sucrose/gelatin > gelatin/medium > gelatin.

Hemiballism-hemichorea: clinical study in 23 Chinese patients

BACKGROUND

Hemiballism-hemichorea, a well documented movement disorder, is not uncommon in the clinic. However, systematic analysis of the condition in ethnic Chinese on clinical grounds, is still inexplicably lacking.

METHODS

This study focused on 23 Chinese patients with hemiballism-hemichorea in Taiwan. The general data, clinical pictures, blood biochemistries, past histories of systemic disease, neuroradiological imaging, methods of treatment, and prognoses of these patients were analyzed retrospectively.

RESULTS

The study revealed that ischemic stroke (44%) is the leading cause of this movement disorder, and the metabolic disorder (22%) is also one of the common etiologies of dyskinesia in Chinese patients. In addition to those patients whose condition was caused by non-ketotic hyperglycemia, blood sugar had also obviously increased in patients where the cause was infarction. Pathological lesions contributed to hyperkinesia were found not only in the contralateral basal ganglion but also in the thalamus and subcortical areas. The characteristics of those patients where the cause was infarction and non-ketotic hyperglycemia were: age at onset greater than 60 years, and predominantly in women. Etiologies contributing to this movement disorder in younger patients differ from those in the older. Prognosis of the movement disorder in this study was favorable.

CONCLUSIONS

Hemiballism-hemichorea is predisposed to occur in older Chinese women, and metabolic disorder is an important etiology of the movement disorder. When the dyskinesia is encountered in the clinic, the metabolic disorders must be first ruled out as the problem may be rapidly resolved by achieving metabolic control.

Preliminary effects of in vitro lipid exposure on absorbable poly(ortho ester) films

Bioabsorbable films show promise in preventing postoperative interfacial tissue adhesion. Absorbable polymers in film form are generally more sensitive to chemical environments, due to their large surface area to volume ratio. The in vivo environment contains lipids such as cholesterol, triglycerides, and phospholipids, which are known to affect the degradation of permanent and absorbable polymeric biomaterials. Preliminary investigations of in vitro lipid exposure of bioabsorbable poly(ortho ester) (POE) films for implant use are described. POE has been studied previously for use in controlled drug delivery and fracture fixation. Six-week in vitro exposure of 65:35 POE films to a cholesterol emulsion (1 g/L) showed no apparent difference in hydrolytic degradation rates of mechanical properties or mass loss compared to deionized water exposed films. Decreases of 28 and 6% in inherent viscosity were observed after 5 weeks for cholesterol and deionized water exposed films, respectively, suggesting cholesterol may have some effect. Further examination of the data, due to sample variation, revealed that clear, uniform films showed only minor changes in mass loss and mechanical properties after 6 weeks in either of the in vitro media. But slightly cloudy films possessing microscopic bubbles showed accelerated degradation in both media, indicating the effect of cholesterol was inconclusive due to sample variation. Control of the microbubble formation process could have utility in controlling hydrolytic degradation of POE films.

[The effects of anticonvulsants on the epileptiform discharges--study by 24-hour ambulatory cassette EEG system]

Thirty-three epileptic children who had epileptiform discharges in conventional 16 channel EEG study were enrolled in this study. The patients have never been treated with medication at first visit. Then patient were put on ambulatory monitoring EEG with the Oxford Medilog 9-channel cassette EEG system, which included six symmetrical scalp leads, one EOG, one Chin EMG and one channel for time signal. The EEG record was processed under the rule of the international standard method in terms of 10-20 system. The 24 hours EEG cassettes which recorded before and after antiepileptic drugs therapy were reviewed by an experienced electroencephalographer on a video play back unit. The number and duration of spikes or spike wave discharges were calculated. Among those 22 cases who had studied completed, there are 11 cases with generalized spike waves (5 with irregular spike waves, 3 with regular 3 hz spike waves, 1 with multiple spike waves, 1 with slow sharp waves and 1 with abortive spike waves), and 11 cases with focal spike activities (5 with bilateral central or centrotemporal spikes, 4 with temporal spikes and 2 with occipital spike discharges). After anticonvulsants therapy, 9 cases (82%) out of those 11 cases with generalized spike waves, the spike waves were disappeared; 2 cases (18%) revealed no significant change in spike rate and duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemiballism-hemichorea and non-ketotic hyperglycaemia

Three patients with hemiballism-hemichorea caused by non-ketotic hyperglycaemia are presented, two of whom had hyperosmolar non-ketotic hyperglycaemic syndrome. In two of the three patients, the hyperkinesia was the initial presenting symptom of their diabetes mellitus. The hypersensitivity of the postmenopausal dopamine receptor, decreased gamma-aminobutyric acid in the brain in non-ketotic hyperglycaemia, coexisting lacunar infarct in the basal ganglion, and pre-existing metabolic dysfunction in the basal ganglion may all have played a part in the pathogenesis of this movement disorder.

Compressive radial nerve palsy induced by military shooting training: clinical and electrophysiological study

Ten recruited soldiers developed acute left wrist drop and numbness on the back of the thumb after a three hour military shooting training. Neurological examination disclosed decreased muscle power (0-2/5) of left wrist dorsiflexion, hypalgesia and hypaesthesia on the radial side of the left hand, and diminished brachioradialis reflex. Electrophysiological studies showed prolonged distal latency, reduced amplitude and slowness of left radial nerve motor conduction velocity between the axilla and elbow. Electromyography (EMG) revealed fibrillation potentials at rest, polyphasic motor unit and an incomplete interference pattern at volition over the extensor digitorum communis and brachioradialis. Nine patients recovered completely clinically and electrophysiologically between nine and 12 weeks after the onset of the palsy. Sensation recovered faster than the weakness. One patient failed to recover after three months, possibly because of the longer duration of nerve compression. Longer nerve compression time and sustained, decreased muscle power with signs of active denervation in EMG are indicators of poor prognosis.

Evolution of a bladder behavior clinic for patients after prostatectomy

The authors describe the ongoing development of a nurse-managed incontinence clinic that focuses on patient responses, adaptions, and goals. They discuss four stages patients must experience when pursuing their goal of continence. Case studies are presented.

Mechanism of hormone-stimulated lipolysis in adipocytes: translocation of hormone-sensitive lipase to the lipid storage droplet

Hormone-sensitive lipase activity (HSL), which is found in the supernatant of centrifuged homogenates of lipolytically quiet isolated rat adipocytes, was greatly reduced in or absent from the supernatant of lipolytically stimulated cells. The lipase was purified 100- to 250-fold from the supernatant of lipolytically quiet cells to 10-20% purity by a single passage over phenyl-Sepharose resin with high (greater than 70%) activity yields. Western blotting of adipocyte homogenate fractions with polyclonal antiserum raised against HSL showed that the enzyme shifted quantitatively from the supernatant of control cells to the floating "fat cake" of lipolytically stimulated cells. A similar shift to the fat cake was observed when cells were disrupted by hypotonic lysis and centrifugation rather than by homogenization. We propose that upon lipolytic activation of adipocytes and phosphorylation of HSL by cAMP-dependent protein kinase, the critical event is not an increase in catalytic activity (i.e., turnover number) but a translocation of the lipase to its substrate at the surface of the lipid storage droplet.

Brachial plexus neuropathy associated with scrub typhus: report of a case

We report on a 20-year-old man who had scrub typhus with the unusual neurologic complication of brachial plexus neuropathy. The clinical features of fever, headache, pneumonitis, eschar, high Weil-Felix OX-K agglutination and Rickettsia tsutsugamushi immunofluorescence titers confirmed the diagnosis of scrub typhus. Brachial plexus neuropathy was proven by an electrophysiologic examination. He had a nearly complete recovery after adequate medical treatment.

Control of endogenous phosphorylation of the major cAMP-dependent protein kinase substrate in adipocytes by insulin and beta-adrenergic stimulation

In isolated, 32Pi-loaded, rat adipocytes, we have examined phosphorylation of the major cAMP-dependent protein kinase (A-kinase) substrate, a protein that appears to be associated with the lipid storage droplet and migrates in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a 65-67-kDa doublet. In control cells, a strong phosphorylation signal is detected as the (+/- cAMP) A-kinase activity ratio ranges from approximately 0.1 to approximately 0.3-0.4 with increasing isoproterenol concentrations. By contrast, insulin-treated cells exhibiting A-kinase activity ratios over the range of 0.1-0.25 contain less 32P in the 65-67-kDa protein than control cells exhibiting identical A-kinase activity ratios. At higher activity ratios (greater than 0.3), this reduction in phosphorylation of the 65-67-kDa protein by insulin disappears. It is concluded that insulin stimulates a phosphatase activity that acts on the 65-67-kDa protein. Insulin actions aside, these studies reveal two interesting phenomena. 1) Whereas elevated, steady-state A-kinase activities are established rapidly (1-2 min) upon isoproterenol stimulation, phosphorylation of the 65-67-kDa substrate proceeds through a burst, followed by a decline to a steady-state level by 10-12 min. An "adaptation" mechanism, providing for a constant response to a constant stimulus, may underlie this lack of parallelism between the time course of phosphorylation and A-kinase activity. 2) Removal of [32Pi] orthophosphate immediately before isoproterenol stimulation leads to a rapid (t approximately 10 min) loss in labeling of the 65-67-kDa protein, whereas the phosphorylation state of other phosphoproteins are not changed. These data suggest that elevation of A-kinase activity leads to a rapid exchange of external Pi with an ATP pool that is used by A-kinase.

Aortic and pulmonary input impedance in patients with cor pulmonale

The hydraulic load of the right and left ventricles and the clinical effects of nifedipine were evaluated in 8 normal subjects (mean age: 55 years) and 8 patients with cor pulmonale secondary to chronic obstructive lung disease (mean age: 57 years). It was found that there were differences in the right ventricular resistance (174.62 +/- 25.96 vs 468.57 +/- 178.81 dyne/sec/cm-5), first zero crossing frequency (3.62 +/- 0.34 vs 6.07 +/- 3.56 Hz), steady power (218.95 +/- 32.25 vs 359.44 +/- 37.46 mW) and total power of right ventricle (275.81 +/- 36.18 vs 440.46 +/- 85.16 mW) between the normal and cor pulmonale patients, respectively. However, no significant changes in characteristic impedance, pulsatile power or aortic impedance were observed in the right pulmonary artery. After administration of nifedipine to patients with cor pulmonale, there were significant changes in resistance (468.57 +/- 178.81 vs 256.36 +/- 178.56 dyne/sec/cm-5), steady power (359.44 +/- 37.46 vs 225.51 +/- 114.64) and total power (440.46 +/- 85.16 vs. 289.27 +/- 50.85) of the pulmonary artery, respectively. Otherwise there were no significant changes in aortic input impedance or characteristic impedance of right pulmonary artery and pulsatile power. In conclusion, we found that: 1) the hydraulic vascular load in the right ventricle was higher in patients with cor pulmonale, 2) characteristic impedance that was not increased in cor pulmonale patients may be due to a dilated pulmonary artery, 3) there was no impedance mismatch between left ventricle and systemic arterial system in patients with cor pulmonale, and 4) by reducing the pulmonary vascular resistance through nifedipine administration, the total external right ventricular power might be reduced, without affecting the proximal pulmonary arterial compliance.

Essential tremor: clinical, electromyographical and pharmacological studies in 146 Chinese patients

From February 1984 to February 1988, 258 cases of various kinds of tremor were seen in our movement disorder clinic. Among them, 146 cases (57%) were diagnosed as essential tremor, and of these, 96 (65.8%) were males and 50 (34.2%) were females, ranging in age from 14 to 89 years (mean: 36 years). The main tremor occurred in the hands (100%), and in a few cases were combined with head, leg, lip, voice and neck tremors. A familial tendency was obvious in 47 cases (32%). The surface electromyographic (EMG) study of essential tremor revealed two patterns, one of synchronous type (73%) and the other of alternating type (27%). Its frequency was between 5 and 9Hz. The burst duration was short (50-100 msec) and the amplitude was low (less than 200 mu v). All cases were divided into two groups to received propranolol therapy, 78 cases with high dosages (120-240 mg/day) and 68 with low dosages (60-80 mg/day). The higher dose was better in effect than the lower one (p less than 0.01). Propranolol also had effect on tremors of alternating type (p less than 0.01), which is different from previous reports.

[Sensory action potentials of ring finger in the diagnosis of carpal tunnel syndrome]

Amplitudes and latencies of sensory action potentials (SAPs) recorded over the index, middle, little and ring fingers by antidromic stimulation of the median or ulnar nerve at wrist were measured in 65 normal adults and 78 patients with clinically and electrophysiologically verified carpal tunnel syndrome. In the normal adults, there was no significant difference among the SAP latencies of the index, middle, ring and little fingers. Among these 65 normal adults, the difference between median and ulnar SAPs of ring finger was less than 0.4 msec in 64 subjects, but 0.7 msec in one. In the patient group, the median distal sensory latency of the ring finger was significantly longer than that of the ulnar nerve which was recorded over the ring and little fingers. Six cases (7.7%) of 78 patients diagnosed as CTS by conventional electrophysiological studies was false negative by using the ring finger sensory action potential study. It is suggested that the SAP study of the ring finger by stimulation of the median and ulnar nerves at the wrist can not replace the conventional electrodiagnostic methods for the diagnosis of carpal tunnel syndrome.

In vitro metabolism of 25-hydroxyvitamin D3 by human trophoblastic homogenates, mitochondria, and microsomes: lack of evidence for the presence of 25-hydroxyvitamin D3-1 alpha- and 24R-hydroxylases

In vitro studies were performed to assess the ability of term human trophoblastic tissue to metabolize 25-hydroxyvitamin D3 (25OHD3) and to compare this metabolism to that occurring in porcine renal mitochondria and microsomes. Human trophoblastic homogenates, containing a NADPH-generating system, were able to produce 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] at a rate of 225 pg/mg protein.h, but did not produce detectable quantities (less than 20 pg/mg protein.h) of 24,25-dihydroxyvitamin D3 [24,25-(OH)2D3]. Similarly, mitochondria and microsomes isolated from term human trophoblastic tissue produced 1,25-(OH)2D3 [249 +/- 156 and 199 +/- 82 (mean +/- SD) pg/mg protein.h, respectively] in the presence of an NADPH-generating system, but failed to produce detectable quantities (less than 200 pg/mg protein.h) of 24,25-(OH)2D3. The production of 1,25-(OH)2D3 from the trophoblastic mitochondria and microsomes could be increased by adding 140,000 x g trophoblastic cytosol to the subcellular incubation tubes. This treatment had no effect on the production of 24,25-(OH)2D3. The component(s) present in trophoblastic cytosol responsible for the increased 1,25-(OH)2D3 production by trophoblastic mitochondria and microsomes was shown to be heat labile, trypsin resistant, and less than 1000 mol wt in size. Comparing characteristics of the porcine renal 1 alpha- and 24R-hydroxylase systems with those of the human trophoblastic system revealed that 1) 1,2-dianilinoethane and EDTA totally blocked synthesis of 1,25-(OH)2D3 in trophoblastic mitochondria and microsomes, but had no effect on the synthesis of 1,25-(OH)2D3 by renal mitochondria; and 2) ketoconazole greatly inhibited the synthesis of 1,25-(OH)2D3 and 24,25-(OH)2D3 by renal mitochondria, but had no effect on the production of 1,25-(OH)2D3 by trophoblastic mitochondria or microsomes. Finally, production of 24,25-(OH)2D3 could not be demonstrated in trophoblastic homogenates, mitochondria, or microsomes, while the production of this compound was readily evident in renal mitochondria, but not microsomes. The results of this study question the existence of the 25-hydroxyvitamin D3-1 alpha- and 24R-hydroxylase systems in the trophoblastic portion of the human placenta. This study also suggests that 1,25-(OH)2D3 can be produced in vitro by a mechanism other than enzymatic 1 alpha-hydroxylation. The possibility exists that the mechanism involves the insertion of oxygen at the 1 position of 25-(OH)D3 by free radical chemistry.

The effect of intravenous captopril on the left ventricular function-an acute study by hemodynamics and radionuclide angiography

Acute hemodynamic effects of intravenous captopril were measured, and left ventricular function was analyzed by radionuclide angiography in 11 patients with moderate to severe hypertension. All subjects received 1 mg captopril bolus injection initially, and followed in 10 minutes intervals by 2 mg or 5 mg injections according to their blood pressure response. Eight patients experienced an acute reduction of blood pressure; three patients remained unresponsive. The onset of action occurred within 5 minutes with peak effect at 5 to 10 minutes and a duration of action of 20 to 30 minutes. The hemodynamic effects were characterized by arteriolar dilation (reduced systemic vascular resistance P less than 0.01), and apparent venous dilatation (reduced right atrial, pulmonary wedge pressure P less than 0.05 & 0.01 respectively). Pulmonary vascular resistance was not altered. Ejection fraction remained unchanged. Isovolumic relaxation period lengthened (109 +/- 20.1 vs 137.39 +/- 21.15 msec, P less than 0.05) and coronary perfusion pressure gradients dropped (113.8 +/- 5.6 vs 101.1 +/- 11.3 mmHg P less than 0.001) following intravenously administered captopril. Intravenous captopril may reduce arterial pressure by inducing arterial dilatation with minimal adverse effect. The prolongation of isovolumic relaxation period should mainly attribute to the decrease of coronary filling load.

[Neuronal heterotopia with hemidystonia]

The vast majority of the patients with dystonia have obscure causes. We present 2 cases of neuronal heterotopia in the basal ganglia, who developed contralateral hemi-dystonia and other nervous system abnormalities in early childhood. The first case was a premature female infant who developed involuntary twist movements of the left arm, persistent plantar flexion and eversion of the left foot at age of 7 months. All of the symptoms disappeared during sleep. Delayed motor milestones were also noted. She was still not able to stand or sit steadily at the age of 17 months. The CT scan of brain revealed a nodular lesion at the margin of right lateral ventricle, which was not enhanced by contrast medium suggesting neuronal heterotopia. Besides, smooth cortical surface, poorly recognizable cortical sulci, agenesis of corpus callosum and dilatation of lateral ventricles were also noted. The second case was a 21-year-old man with involuntary movements of left side body and limbs since his early childhood. He had persistent twist and intermittent jerky movements of the left limbs and torticollis. The patient also showed dysarthria and mild mental retardation. The CT scan of brain showed a heterotopic nodule at the margin of right lateral ventricle. The 2 cases reported here suggest that the early onset of hemi-dystonia with multiple nervous system disorders and the abnormal neuronal migration in human embryonic stage are related.

[Isoniazid therapy in severe cerebellar, postural and kinetic tremor]

In the routine analysis of patients with tremors, we have the routine analysis of patients with tremors, we have encountered three patients with severe cerebellar postural & kinetic tremors. Surface EMG study revealed alternating activity in antagonistic muscles with low frequency (3-5 cps) and wide duration (over 125msecs). They were different to typical essential tremor & parkinson's tremor in the clinical manifestation and tremogram. The tremor did not respond to high dose of propranolol (120-160mg/day), but responded to high dose of isoniazid (800-1200mg/day). Patients were evaluated before & after INH therapy with videotaping, surface EMG quantitative recording. One patient had transient side effects (abnormal liver function) in the beginning of treatment possibly because he was a "slow acetylator". The possible mechanism of effort of INH was discussed.

Selection and implementation of Dr. Martha Rogers' nursing conceptual model in an acute care setting

The Nursing Service of the San Diego Veteran's Administration Medical Center identified the need to implement a nursing conceptual model as a basis for practice. The process of choosing and implementing Dr. Martha Rogers' conceptual model is discussed and examples of clinical application are included.

A tandem chromatographic column method for assaying cAMP-dependent protein kinase and protein kinase C with synthetic peptide substrates

A method was devised for assaying protein kinases that phosphorylate either Kemptide, such as cAMP-dependent protein kinase, or a glycogen synthase peptide, which is an excellent substrate for protein kinase C. Upon sequential processing of reaction mixtures through tandem columns of cation and anion exchange resins, radioactivity in background samples is nearly nil and the yield of phosphorylated peptides is high. This method reduces labor, radioactivity, enzyme requirements, and costs of assaying protein kinases.

Herpes zoster: epidemiology, clinical features, and management

Herpes zoster is a commonly encountered infectious disease primarily affecting the elderly and immunosuppressed. The natural history and complications of the disease and the principles of management are often not appreciated by clinicians in a variety of disciplines who may see the patient during the acute phase. Recent literature has furthered our understanding of the virology of herpes zoster and the roles of corticosteroid and antiviral therapy. We review the clinical features, diagnostic principles, and management controversies of herpes zoster.

Pseudothrombophlebitis syndrome in the arthropathy of granulomatous colitis

A case of pseudothrombophlebitis syndrome occurred in a young man with colitic arthropathy who was seen because of a swollen leg. The salient features of this syndrome, the difficulty in differentiating it clinically from true deep venous thrombosis, and the importance of correct diagnosis are stressed, particularly in light of the fact that patients with inflammatory bowel disease are predisposed to occlusive venous disease.

Some Effects of Actinomycin D, Cycloheximide and Puromycin on Cell Adhesion

The metabolic inhibitors cycloheximide, puromycin and actinomycin D, increased the rate of adhesion of Ehrlich ascites tumour cells to coverslips and plastic surfaces, over periods of up to 2 h in vitro. Among a number of possible explanations of this effect is a decreased production of hypothetical anti-adhesion factor(s). It is suggested that the difference between the increased rate of adhesion observed by us, and the decrease or lack of effect of the drugs observed by others, is related to prior trypsin-treatment of cells by the other observers.