Useful panel of antibodies for the classification of acute leukemia by immunohistochemical methods in bone marrow trephine biopsy specimens

To evaluate the feasibility of acute leukemia typing on routinely processed bone marrow biopsy specimens, 72 cases of previously established acute leukemia covering the spectrum of 17 known subtypes were studied immunohistochemically. Most leukemic myeloblasts were positive for myeloperoxidase in 16 (84%) of 19 cases of acute myeloid leukemia, M1-M4, and M6. Most leukemic cells in 11 of 12 M4 and M5 cases were positive for CD68 (PG-M1). All six M6 cases stained with hemoglobin. Leukemic megakaryoblasts in three of four M7 cases were positive for factor VIII-related antigen. Almost all leukemic cells of 8 T-lineage acute lymphoblastic leukemia (ALL) and 19 B-lineage ALL cases were positive for CD3 and CD79a (HM57), respectively. Staining with CD20 (L26) was positive in the more differentiated B-lineage ALL cases and strongest in L3. Immunohistochemical typing of acute leukemia is possible for most types using this panel of cell lineage-specific antibodies.

Field programmable gate array in a fast 256-channel data acquisition system

We describe an FPGA (Field Programmable Gate Array) controlled fast data acquisition system with 256 channels suitable for high resolution electrocardiographic (ECG), electrogastrographic (EGG) and late potential (LP) recordings. The A/D converter provides 800ns conversion time with 12 bits. The S11W, a 16 bit, parallel, I/O interface, is used to connect the data acquisition device to a portable SPARC-compatible computer. With only one A/D converter, we have achieved 2 kHz sampling rate for each channel and more than 1MB/s overall by using an overlapping delay technique. Channel parameters can be selected independently from one of eight gains ranging from 50 to 10,000, and one of three filters ("ECG" 0.05-120Hz, "EGG" 0.001-1Hz and "LP" 60-1kHz). There are eight programmable sampling frequencies from 2Hz to 2kHz. The system is fully battery operated and protected from the defibrillation high voltages to meet the safety requirements. The acquisition system can be widely used in medical research and clinical applications.

Patterns of recovery in the Guillain-Barre syndromes

Clinical, electrodiagnostic, and pathologic studies indicate that the Guillain-Barre syndromes (GBSs) include both primary demyelinating and primary axonal forms. The axonal forms are usually thought to have a poorer prognosis, with less chance for rapid or complete recovery. In northern China, epidemics of one axonal form, acute motor axonal neuropathy (AMAN), occur annually in the summer. Autopsy studies in some fatal cases have demonstrated wallerian-like degeneration of motor roots and motor fibers in the peripheral nerves. Recovery of such patients would require axonal regeneration along the entire length of the nerve fiber. In a 2-year prospective study of GBS at a single hospital in northern China, 42 patients were classified as having either AMAN (32 patients), acute inflammatory demyelinating polyneuropathy (AIDP) (8 patients), or as undetermined (2 patients) by electrodiagnostic criteria. Their recoveries were monitored clinically. The recovery times of AMAN and AIDP patients were similar: the median time to regain the ability to walk 5 meters with assistance was 31 days for patients classified as having AMAN and 32 days for those classified as having AIDP. These rapid recovery times are incompatible with severe wallerian degeneration of the ventral roots and motor nerve fibers. The rapid recoveries observed in AMAN patients could be explained by relatively quickly reversible immune-mediated changes at nodes of Ranvier in motor fibers, by degeneration and regeneration of intramuscular motor nerve terminals, or both.

Bone marrow granulomas associated with chronic natural killer cell lymphocytosis

Two patients with chronic natural killer cell lymphocytosis (CNKL) and associated bone marrow granulomas (BMGs) are described. The increases in the peripheral blood of both the proportion (64 and 74%) and absolute number (2,000/microL and 4,700/microL) of NK cells have persisted for more than 1 and 3 years. One patient was asymptomatic with thrombocytopenia and neutropenia, and the other presented with fever of unidentified origin, which has since responded to a nonsteroidal anti-inflammatory agent. Bone marrow examination in both patients showed loose aggregates of epithelioid histiocytes similar to the noncaseating granulomas seen in other diseases. An unusual feature, however, was the presence of many scattered, large mononuclear histiocytes that were morphologically similar to atypical megakaryocytes. Extensive clinical and laboratory studies did not reveal an established cause for the BMGs. BMGs may be associated with CNKL, with the unusual feature of scattered, atypical mononuclear histiocytes.

The lost endotracheal tube--a rare complication of accidental esophageal intubation

Endotracheal intubation is a discreet skill for the management of compromised airway. Various complications associated with this procedure have been described. Here, we would like to present a pediatric patient suffering from cerebellar atrophy, who was intubated in a local clinic due to seizure with cyanosis and loss of consciousness. Unfortunately, due to inadvertent esophageal intubation and bad management, the patient swallowed the endotracheal tube together with two detached loose teeth. This irrational and iatrogenic medical misconduct as exemplified in this accident calls forth the need of educating and disciplining the nonanesthetic physicians for acute management of airway, particularly of those who would likely come across difficult airway problems.

Residential exposure to 60-Hertz magnetic fields and adult cancers in Taiwan

We conducted a case-control study, using matching on date of birth, sex, and date of diagnosis, in northern Taiwan to evaluate the risks of adult leukemia, brain tumors, and female breast cancers in relation to residential exposure to 60-Hertz (Hz) magnetic fields. Cases were persons with newly diagnosed cancers reported to the cancer registry between 1987 and 1992, and controls were persons with cancers sites other than those previously suspected of being associated with magnetic fields. Magnetic fields in the residences occupied by the study subjects at the time of diagnosis were estimated from high-voltage transmission lines. The results were based on the separate analysis of 870 cases of leukemia, 577 brain tumors, and 1,980 female breast cancers. We estimated the risk of leukemia among those exposed to magnetic fields of > 0.2 microtesla (microT), relative to the risk among those exposed to fields of < 0.1 microT; the odds ratio was 1.4 [95% confidence interval (CI) = 1.0-1.9]. For distance < 50 meters relative to > or = 100 meters, the relative risk was 2.0 (95% CI = 1.4-2.9). For brain tumors and female breast cancers, the odds ratios were close to unity.

Mortality among benzene-exposed workers in China

A large cohort of 74,828 benzene-exposed and 35,805 nonexposed workers employed between 1972 and 1987 in 12 cities in China was followed to determine mortality from all causes. Benzene-exposed study subjects were employed in a variety of occupations including coating applications, and rubber, chemical, and shoe production. Mortality was slightly increased among workers with greater cumulative exposure to benzene (ptrend < 0.05), but this excess was largely due to cancer deaths (ptrend < 0.01). Deaths due to lymphatic and hematopoietic malignancies (ptrend = 0.01) and lung cancer (ptrend = 0.01) increased with increasing cumulative exposure to benzene. Investigations continue to relate benzene exposure to specific lymphatic and hematopoietic malignancies and other causes of death.

Clinical features of hematopoietic malignancies and related disorders among benzene-exposed workers in China. Benzene Study Group

Previous occupational cohort studies of benzene-exposed workers have for the most part used only death certificates to validate diagnoses of workers developing leukemia and other hematopoietic and lymphoproliferative malignancies and related disorders (HLD). In a follow-up study of 74,828 benzene-exposed workers and a comparison group of 35,805 nonexposed workers from 12 cities in China, we sought to characterized clinicopathologically and to confirm diagnoses of all cases of HLD. Using medical records, laboratory hematology results, and histopathology, U.S. and Chinese expert hematopathologists, blinded to exposure status, carried out a detailed review using standardized evaluation forms. Key among the findings were a notable diversity of malignant and nonneoplastic hematopoietic and lymphoproliferative disorders, documentation of excess myelodysplastic syndromes among benzene workers, and widespread dyspoiesis involving all hematopoietic cell lines. As sophisticated clinicopathologic characterization and corresponding classification schemes for HLD become increasingly widespread, it is recommended that future epidemiologic investigations of benzene workers incorporate similarly detailed morphologic evaluation. In extending follow-up of this cohort of young workers, we will continue to use all available clinical, laboratory hematology, and pathology data as well as cytogenetic and biochemical markers to characterized various HLD outcomes. These careful surveillance mechanisms should also provide additional insight into carcinogenic mechanisms of benzene and allow comparison of the molecular pathogenesis of HLD induced by benzene versus chemotherapy, radiation, or other exposure.

Heterogeneity and clinical relevance of the intensity of CD20 and immunoglobulin light-chain expression in B-cell chronic lymphocytic leukemia

In a prospective study, peripheral lymphocytes of 93 previously untreated patients with B-cell chronic lymphocytic leukemia (B-CLL) were evaluated with flow cytometry for the intensity of CD20 and surface immunoglobulin (sIg) light-chain (LC) expression. Molecules of equivalent soluble fluorescence were used to classify intensity of surface antigen expression as "strong," "moderate," or "weak." Despite reproducible morphological consistency with B-CLL, variability in intensity of CD20 and sIg light chain expression was substantial. CD20 intensity was classified as weak in 62% of patients, moderate in 12%, and strong in 26%. Expression of sIg light chain was weak in 76% and strong in 24%. The patients were followed up for a median of 3.1 years. Intensity of expression of CD20 and sIg light chain was not correlated with any presenting feature at the time of phenotyping, including clinical stage and degree of lymphocytosis or organomegaly. Similarly, clinical course of the disease, time to progression, response to therapy, and overall and treatment-free survival were not predictable from the intensity of CD20 or sIg light chain expression. In conclusion, bright expression of CD20 or sIg light chain is not an unusual feature in B-CLL and may not influence clinical presentation or short-term prognosis.

The premortem recognition of systemic senile amyloidosis with cardiac involvement

PURPOSE

To recognize systemic senile amyloidosis involving the heart and to determine outcome.

PATIENTS AND METHODS

All patients with the diagnosis of amyloidosis at the Mayo Clinic from January 1, 1984 through May 1, 1992, were reviewed. Amyloid was confirmed histologically by sulfated alcian blue and alkaline Congo red staining. The labeled streptavidin-biotin immunoperoxidase method was used with antisera against A kappa, A lambda, AA, transthyretin, and beta 2-microglobulin. Anti-P-component and antisera to albumin were used as controls. Chest radiographs, electrocardiograms, transthoracic echocardiograms, and cardiac catheterization data of all patients were reviewed. Serum and urine were examined with immunoelectrophoresis and immunofixation for the presence of a monoclonal protein. Lymphocyte DNA was examined for transthyretin mutations associated with familial amyloidosis.

RESULTS

We identified 18 patients with myocardial tissue that stained positive for amyloid with sulfated alcian blue and Congo red and with transthyretin antisera. Congestive heart failure was present at diagnosis in 17 of the 18 patients. Atrial fibrillation was found in 11 patients. No monoclonal protein was found in the serum or urine. The echocardiographic findings were consistent with infiltrative cardiomyopathy due to amyloidosis in 16 patients. Right heart pressures were elevated in all 7 patients who had right-side heart catheterization. No transthyretin mutations were found in the leukocyte DNA from 12 patients. The actuarial median survival was 5 years; in contrast, the median survival was 5.4 months in 147 patients with primary amyloidosis (AL) who presented with congestive heart failure.

CONCLUSION

Patients with cardiac amyloid and no monoclonal protein in the serum or urine must have immunohistochemical staining for kappa and lambda light chains and transthyretin to distinguish between systemic senile amyloidosis, familial amyloidosis, and AL. Patients with systemic senile amyloidosis should not be treated with alkylating agents. Their survival is much longer than that of patients with AL (60 versus 5.4 months).

Acute motor axonal neuropathy: an antibody-mediated attack on axolemma

The acute motor axonal neuropathy (AMAN) form of the Guillain-Barre syndrome is a paralytic disorder of abrupt onset characterized pathologically by motor nerve fiber degeneration of variable severity and by sparing of sensory fibers. There is little demyelination or lymphocytic inflammation. Most cases have antecedent infection with Campylobacter jejuni and many have antibodies directed toward GM1 ganglioside-like epitopes, but the mechanism of nerve-fiber injury has not been defined. In 7 fatal cases of AMAN, immunocytochemistry demonstrated the presence of IgG and the complement activation product C3d bound to the axolemma of motor fibers. The most frequently involved site was the nodal axolemma, but in more severe cases IgG and C3d were found within the periaxonal space of the myelinated internodes, bound to the outer surface of the motor axon. These results suggest that AMAN is a novel disorder caused by an antibody- and complement-mediated attack on the axolemma of motor fibers.

Experimental Campylobacter jejuni infection in the chicken: an animal model of axonal Guillain-Barré syndrome

OBJECTIVE

To develop and characterise an animal model of paralytic neuropathy after Campylobacter jejuni infection. Campylobacter infection precedes development of many cases of Guillain-Barré syndrome and is particularly associated with cases having prominent axonal degeneration. Understanding the pathogenesis of Guillain-Barré syndrome after C jejuni infection has been slowed by the lack of animal models.

METHODS

A spontaneous paralytic neuropathy is described that developed in chickens from the farms of four patients with Guillain-Barré syndrome. The production of paralytic neuropathy in chickens experimentally fed Campylobacter jejuni isolated from one of these patients is reported. The sciatic nerves of the spontaneously paralysed chickens were examined pathologically in teased fibres, in plastic embedded sections, and by electron microscopy. Two large groups of chickens were then fed cultures of a C jejuni (Penner type O:19) isolated from one of these patients.

RESULTS

The chickens with spontaneous paralysis had pathologically noninflammatory neuropathy. Pathology in the sciatic nerves ranged from no detectable changes to severe Wallerian-like degeneration. In the experimentally inoculated groups, an average of 33% of the chickens became paralysed. The median time after inoculation to paralysis was 12 days. The lesions found in the first few days of paralysis included nodal lengthening and paranodal demyelination. In those animals that survived for several days after onset of weakness, the pathology was dominated by extensive Wallerian-like degeneration. Animals that survived for weeks with no clinically apparent neuropathy had paranodal remyelination in some teased nerve fibres, reflecting earlier paranodal demyelination.

CONCLUSION

Experimental inoculation with C jejuni may provide a new model for understanding some forms of Guillain-Barré syndrome.

Estimation of the optimal concentrations of residual sugar and cell growth rate for a fed-batch culture of Saccharomyces cerevisiae

Estimation of the optimal concentrations of residual sugar in medium for a fed-batch culture of Baker's yeast has been studied and practiced. The concentrations, however, depended on different species and targets of the biomass, which was expected to be made. Kinetic changes of the residual phosphate salt in the medium conformed to a logarithmic process until the fourth hour during an 11-h culture. The parabolic method (see ref. 9 later in article) might be qualified to maintain the concentrations of residual sugar around 0.15 g/L. It was demonstrated that cell growth followed a sigmoid process during a fed-batch culture, because the cells consumed the nutrient with two metabolic pathways, one was for cell conversion and another was for non-cell conversion. With the parabolic method, we can estimate kinetics of cell growth and cell growth rate during the culture.

Abrogation of P53 function by transfection of HPV16 E6 gene does not enhance resistance of human tumour cells to ionizing radiation

Suppression of wild-type p53 expression has been shown to enhance the radiation resistance of human diploid fibroblasts, but results concerning the role of p53 expression in the sensitivity of human tumour cells have been conflicting. In order to address this question, we transfected four human tumour cell lines with the human papilloma virus 16 E6 gene and compared the radiosensitivity of subclones expressing E6 with that of subclones transfected with the neo gene alone. E6 binds to wild-type p53 promoting its degradation and abrogating its function. Two of these cell lines, one derived from a squamous cell carcinoma and the other an osteogenic sarcoma, expressed wild-type p53. The other two cell lines were of similar origins and histologies but expressed mutant or no p53 (null). Insertion of E6 into the cell was accomplished by two techniques: (1) to-transfection of plasmid vectors containing neo and E6; (2) infection with a retroviral vector containing neo and E6. Multiple transfected subclones were examined for each cell line. Transfection with E6 and abrogation of p53 function had no significant influence on the radiosensitivity of any of the cell lines tested. In particular, there was no evidence that loss of wild-type p53 function increased the resistance of these human tumour cell lines to ionizing radiation.

Epidemiological appraisal of studies of residential exposure to power frequency magnetic fields and adult cancers

OBJECTIVES

To appraise epidemiological evidence of the purported association between residential exposure to power frequency magnetic fields and adult cancers.

METHODS

Literature review and epidemiological evaluation.

RESULTS

Seven epidemiological studies have been conducted on the risk of cancer among adults in relation to residential exposure to power frequency magnetic fields. Leukaemia was positively associated with magnetic fields in three case-control studies. The other two case-control studies and two cohort studies did not show such a link. Brain tumours and breast cancer have rarely been examined by these studies. Based on the epidemiological results, the analysis of the role of chance and bias, and the criteria for causal inferences, it seems that the evidence is not strong enough to support the putative causal relation between residential exposure to magnetic fields and adult leukaemia, brain tumours, or breast cancer. Inadequate statistical power is far more a concern than selection bias, information bias, and confounding in interpreting the results from these studies, and in explaining inconsistencies between studies.

CONCLUSIONS

Our reviews suggested that the only way to answer whether residential exposure to magnetic fields is capable of increasing the risks of adult cancers is to conduct more studies carefully avoiding methodological flaws, in particular small sample size. We also suggested that the risk of female breast cancer should be the object of additional investigations, and that future studies should attempt to include information on exposure to magnetic fields from workplaces as well as residential exposure to estimate the effects of overall exposure to magnetic fields.

Spectrum of diseases associated with increased proportions or absolute numbers of peripheral blood natural killer cells

In a retrospective review of 1501 lymphoid flow cytometric studies of peripheral blood, we identified an increased proportion of natural killer cells in 125 cases (8%), 49 (3%) of which had a concomitant increase in absolute number of natural killer cells. Of the latter, the most frequent associated disorder was chronic natural killer cell lymphocytosis. Substantial quantitative increases in natural killer cells were also observed in some patients with lymphoma, leukaemia, immune thrombocytopenic purpura, or myelodysplastic syndrome. Our study provides incidence figures and clinical associations of an increased number of natural killer cells in the peripheral blood.

Solubilization of retinoids by bile salt/phospholipid aggregates

PURPOSE

The capacity and specificity of bile salt (BS)/ phosphatidylcholine (PC) mixed lipid aggregated systems in solubilizing four structurally related retinoids, etretinate, motretinid, fenretinide and N-ethyl retinamide, were determined.

METHODS

Excess solid drug was dispersed into sodium taurocholate (NaTC)/egg PC systems at lipid ratios of 10:0, 10:2 and 10 mM:10 mM in isotonic HEPES buffer, pH 6.5. A sensitive HPLC method was used to quantify the amount solubilized. The melting point and associated enthalpy change as well as the aqueous solubilities were also measured.

RESULTS

The retinoids had aqueous solubilities of less than 25 nM. The predicted aqueous solubility was less than 0.01 nM. The amount of retinoid in 10 mM NaTC was increased from three to four orders of magnitude relative to the aqueous solubility. Further increases in the amount solubilized were observed in the 10:10 mixed micelle dispersion. Fenretinide and N-ethyl retinamide were particularly well solubilized by BS and BS/PC aggregated systems which may be related to the presence of a cyclohexenyl ring.

CONCLUSIONS

The discrepancy between the observed and predicted aqueous solubility may be due to self-association of the retinoids. Micellar/aqueous distribution ratios appear to be dominated by the hydrophobic effect, although specific interactions also are important. In considering intestinal absorption, the large increase in solubilization with BS/PC micelles would be capable of dramatically increasing the bioavailability in spite of the smaller effective diffusivity of the solubilized retinoid.

Immune attack on the Schwann cell surface in acute inflammatory demyelinating polyneuropathy

The localization, mode of action, and roles of complement in the Guillain-Barre syndrome have been controversial. We used high-resolution immunocytochemistry to localize complement activation products in early stages of the acute inflammatory demyelinating polyneuropathy (AIDP) pattern of Guillain-Barre syndrome. Three AIDP subjects who were autopsied had had symptoms for 3 to 9 days at the time of death. Immunocytochemistry was performed on etched, epoxy resin-embedded sections, and the next thin section was compared by electron microscopy (thick/thin sections). Many fibers had a rim of the complement activation marker C3d and the terminal complement complex neoantigen C5b-9 along the outer surface of the Schwann cells. Ultrastructural analysis of these C3d-positive fibers showed mild vesicular changes of the outermost myelin lamellae. Vesicular degeneration was seen before the invasion of macrophages into the myelin, and was the predominant change in the subject with symptoms for 3 days. C3d staining was not found on myelin membranes. The results suggest that at least some forms of AIDP are complement mediated. We speculate that complement is activated by antibody bound to epitopes on the outer surface of the Schwann cell and that the resulting complement activation initiates the vesiculation of myelin.

A study of patients' acceptance towards vaginal birth after caesarean section

Patients' acceptance towards vaginal birth after Caesarean section (VBAC) was studied in 99 women with previous Caesarean section. Their attitude was strongly related to the chance of success of VBAC. Only 53.3% of patients would accept VBAC if they were told that the chance of success was 70%. A history of vaginal delivery and a negative feeling towards previous operation were positively associated with acceptance of VBAC (p < 0.01), while convenience of elective Caesarean section and fear of vaginal delivery (even although most of them had had no vaginal delivery before) were the commonest reasons for refusal. The major caused of a negative feeling towards the previous Caesarean section were postoperative pain and a long recovery period. There was no significant negative effect on acceptance of VBAC if the previous Caesarean section was performed as an emergency operation for slow progress of labour or cephalopelvic disproportion.

Diffusivity of bile salt/phospholipid aggregates in mucin

PURPOSE

The objective of this study is to evaluate the effect of the mucous layer on the transport of the drug-solubilizing bile salt/phosphatidylcholine (BS/PC) aggregates.

METHODS

The self-diffusion coefficient of BS/PC aggregates in bovine submaxillary mucin (BSM) was measured by Fourier-transform pulsed-field gradient spin-echo (FT-PGSE) 1H NMR spectroscopy.

RESULTS

In spite of the complexity of the mixture, the FT-PGSE technique allowed the unambiguous determination of the diffusivity of PC and 1H2HO (HDO, natural abundance in D2O). With a series of BS/PC total lipid concentrations ranging from 1 to 7 g/dl, a progressive decrease in the effective diffusivity of HDO was observed with an increase in the both the BSM and total lipid concentration. The effective diffusivity of PC decreased with increasing lipid concentrations in the presence of mucin, while in the controls it increased. After correcting the effective diffusivity of PC for the obstruction effect of mucin, the size of the BS/PC mixed micelle was assessed. It appears that PC associates with BSM resulting in a decrease in the available PC for micellization. This reduces the average size of the mixed micelle within the mucous layer.

CONCLUSIONS

The aggregation state of BS/PC micelle is altered by the presence of mucin which would have a direct impact on the transport of dietary lipid and solubilized drug through the aqueous boundary layer of the intestinal tract.

A cohort study of cancer among benzene-exposed workers in China: overall results

A large cohort study of 74,828 benzene-exposed and 35,805 unexposed workers employed between 1972 and 1987 in 12 cities in China were followed to determine mortality from all causes and the incidence of lymphohematopoietic malignancies and other hematologic disorders. Benzene-exposed study subjects were employed in a variety of occupations, including painting, printing, and the manufacture of footwear, paint, and other chemicals. All-cause mortality was similar in the benzene-exposed and unexposed comparison group. Statistically significant excess deaths were noted among benzene-exposed subjects for leukemia (RR = 2.3, 95% CP 1.1-5.0), malignant lymphoma (RR = 4.5, 95% CI: 1.3-28.4), and nonneoplastic diseases of the blood (RR = 95% CP 2.5-infinity), and a marginally significant excess was noted for lung cancer (RR = 1.4, 95% CI: 1.0-2.0). Risk was significantly elevated for the incidence of all lymphohematopoietic malignancies (RR = 2.6, 95% CI: 1.5-5.0), malignant lymphoma (RR = 3.5, 95% CI: 1.2-14.9), and leukemia (RR = 2.6, 95% CI.. 1.3-5.7). Among the leukemia subtypes, only acute myelogenous leukemia (AML) incidence was significantly elevated (RR = 3.1, 95% CI: 1.2-10.7), although nonsignificant excesses were also noted for chronic myelogenous leukemia (CML) (RR = 2.6, 95% CI: 0.7-16.9) and lymphocytic leukemias (RR = 2.8, 95% CI.. 0.5-54.5). Significant excesses were found for aplastic anemia (RR = infinity, 95% CI: 2.2-co) and myelodysplastic syndrome (RR = infinity, 95% CI: 1.7-infinity). Employment in benzene-associated occupations in China is associated with a wide spectrum of myelogenous and lymphocytic malignant diseases and related disorders. Investigations continue to assess the nature of these associations.

Early nodal changes in the acute motor axonal neuropathy pattern of the Guillain-Barré syndrome

The axonal patterns of Guillain-Barré syndrome, associated in many cases with antecedent Campylobacter jejuni infection, are now recognized as frequent causes of acute flaccid paralysis in some regions of the world. This study examined ultrastructurally the PNS of seven cases of the acute motor axonal neuropathy form of Guillain-Barré syndrome. In this disorder previous studies of advanced cases have found Wallerian-like degeneration of motor fibres in the spinal roots and peripheral nerves, with little lymphocytic inflammation or demyelination. The present study was focused on identifying early changes and establishing the sequence of changes. By electron microscopy the earliest and mildest changes consisted of lengthening of the node of Ranvier with distortion of the paranodal myelin, and in some instances with breakdown of the outermost myelin terminal loops. At this stage many nodes had overlying macrophages which extended their processes through the Schwann cell basal lamina covering the node and apposed the axolemma. Macrophage processes then extended beneath the myelin terminal loops, and the whole macrophage entered the periaxonal space at the paranode. Macrophage processes dissected the axon from the adaxonal Schwann cell plasmalemma and the macrophages advanced into the internodal periaxonal space, where they typically surrounded a condensed-appearing axon. At this stage the adaxonal Schwann cell cytoplasm regularly degenerated and disappeared, so that the periaxonal space was bounded by the innermost myelin lamella, and the axolemma of many fibres could not be seen. The internodal myelin sheath and the abaxonal Schwann cell cytoplasm remained normal. This arrangement appeared to be stable for some time, but in many fibres the axon subsequently underwent Wallerian-like degeneration. By interfering with impulse conduction, these nodal and periaxonal changes may explain paralysis in some pathologically mild cases. In addition, at early stages, these changes may be reversible, thus explaining the rapid recovery of some patients who become paralysed with acute motor axonal neuropathy. These observations, taken together with previous studies, suggest that acute motor axonal neuropathy is an antibody- and complement-mediated disorder in which the relevant epitopes are present on the nodal and internodal axolemma.

[Quantitative study on the effect of osthole on proximal tibiae in ovariectomized (OVX) rats]

Thirty-one 3-month-old Female Sprague-Dawley rats were randomly divided into 5 groups, basal control (group 1, killed at the begining), aging control (group 2), ovariectomized (OVX, group 3), OVX with nilestriol treatment group (group 4) and OVX with osthole treatment group (group 5). Group 2 and group 3 ig with water 5 ml.kg-1 and group 5 ig with osthole 6.7 mg.kg-1, all once a day for 6 d; group 4 ig with nilestriol 1 mg.kg-1, once a week. After 12 weeks, all rats were killed. The proximal tibiae of rats were processed to undecalcified sections at 20 microns thickness for histomorphometric analysis. OVX was shown to reduce markedly the trabecular bone mass (%Tb. Ar-59%) due to increase of bone turnover with the result that bone resorption exceeded bone formation, as compared with aging controls. In contrast, treatment of OVX rats with Osthole and nilestriol increased significantly the trabecular area (increased 68% and 27.1% compared with that of OVX respectively). Our results indicate that osthole and nilestriol treatment provides protection against osteoporosis in OVX rats. The protective mechanism of osthole and nilestriol involves supression of bone turnover, but the effects of osthole is lower than that of nilestriol (trabecular area decreased 55% more in osthole group than that with nilestriol treatment). Our finding may provide theoretical evidence for the clinical use of osthole or nilestriol for treatment and prevention of osteoporosis.