[Clinical effectiveness and tolerance of acarbose in the treatment of insulin-dependent diabetic patients (type I)]

BACKGROUND

Acarbose is a reversible inhibitor of the intestinal alpha-glucosidases, the oral administration of which delays or diminishes the postprandial increase of glucose and insulin.

METHODS

A multicentric double-blind clinical trial (11 centers), controlled versus placebo, crossed and randomized, was carried out with 137 insulin-dependent diabetic type I patients treated with diet and insulin. During the first 3 months of the trial the patients received placebo or acarbose randomly. Following one month of wash out with placebo the patients received the inverse medication for 3 more months. During the first month of each phase the patients were given 50 mg three times per day of acarbose or placebo and the two following moths received 100 mg x 3/day.

RESULTS

Upon comparison of the two treatments significant statistical differences were found in HbA1 (p = 0.0005) and in postprandial glycemia (p = 0.007). There were differences, although not statistically significant, in the amounts of triglycerides, cholesterol and fasting glycemia. One hundred and two patients referred adverse events, most being gastrointestinal (flatulence, meteorism).

CONCLUSIONS

Acarbose may be useful in the treatment of insulin-dependent diabetic type I patients treated with insulin and diet since it reduces the levels significantly of HbA1 and postprandial glucose.

[Clinical efficacy and tolerance to acarbose in the treatment of non-insulin-dependent diabetic patients]

BACKGROUND

Acarbose is a pseudotetrasacaride which reversibly and competitively inhibits the intestinal alpha-glycosidases leading to a decrease in the increase of postprandial glycemia.

METHODS

A multicentric double-blind clinical trial (8 centers), controlled versus placebo, crossover and randomized was carried out in 90 non insulin dependent diabetic patients under treatment with diet or with diet and sulphonilureas. During the first three months of the trial the patients received placebo or acarbose randomly. Following one months of wash-out with placebo the patients received the inverse medication for 3 more months. During the first month of each phase the patients received 3 x 50 mg/day of acarbose or placebo and the following 2 months 3 x 100 mg/day.

RESULTS

Upon comparison of the two treatments significant statistical differences were observed in HbA1 (p = 0.0115) and in postprandial glycemia (p = 0.0001). There were differences, although not significant, in the levels of triglycerides, cholesterol, fasting glycemia, and postprandial insulinemia. Episodes of hypoglycemia appeared in 12 patients and 57 patients referred undesirable gastrointestinal effects.

CONCLUSIONS

The results of this trial indicate that acarbose may be useful in the treatment of non insulindependent diabetic patients since it significantly reduces the amount of postprandial glycemia and HbA1.

GH secretion status in myotonic dystrophy

Frequent endocrine alterations and abnormal growth hormone (GH) secretion have been reported in myotonic dystrophy (MD). To evaluate GH secretion status in MD, GH response to 100 micrograms of growth hormone releasing hormone (GHRH) with or without pyridostigmine pretreatment and its relation with insulin-induced hypoglycemia was investigated in MD patients and compared with normal controls. The mean peak plasma GH response to GHRH was 27.8 +/- 19.2 micrograms/l normal subjects and 11.4 +/- 8.7 micrograms/l in MD patients. In five of seven patients GH reached a mean peak of 12.6 +/- 4.2 micrograms/l after insulin-induced hypoglycemia, compared with 5 +/- 2.8 micrograms/l after GHRH. Conversely, in two patients GH reached a peak of 16.1 and 32 micrograms/l after GHRH, and only 2.5 and 5.3, respectively, after hypoglycemia. Pretreatment with pyridostigmine in nine patients tested potentiated GHRH-induced GH release with a peak of 17.6 +/- 12.5 micrograms/l, compared with 10.05 +/- 6.7 micrograms/l after GHRH alone; IGF-I levels were normal in all patients.

[Hypophyseal apoplexy: clinico-radiologic analysis and clinical course in 18 patients]

The period of time between clinical manifestations and admission of 18 patients with pituitary apoplexy (PA) was of a mean of 6 days with the exception of two cases. Distribution by age and sex, absence of previous endocrinal clinical manifestations in 38.8% of the patients was similar to that of larger series described. Headache constituted an almost constant symptom. The most affected cranial pairs were II (12 patients), III and IV, both in 8 cases. Following decompression surgery, great improvement was observed in visual acuteness in 5 of these patients, and in the ophthalmoplexy in 8. Alterations in the level of consciousness is less and less frequent in the context of PA thanks to the diagnosis of less severe clinical episodes. Similarly, a high rate of clinical suspicion and the use of new imaging techniques (NMR) have contributed notably with the most outstanding findings being resumed. Moreover, a case of PA with associated intracranial aneurysm verified by carotid angiography is described.

Salivary testosterone as an index of antiandrogen therapy in hirsutism

The purpose of this study is to examine whether salivary testosterone (ST) in hirsute women treated with antiandrogen therapy can be considered a good parameter for the evaluation of clinical response. Twenty-three hirsute women, four with polycystic ovarian disease and 19 with idiopathic hirsutism were treated with cyproterone acetate and ethynyl-oestradiol with levonorgestrel in a reverse sequential regime for three months. Basal ST from hirsute women was 0.18 +/- 0.11 nmol/L (normal values 0.03-0.17) and a decrease to 0.11 +/- 0.06 was observed in the first month of treatment, to 0.1 +/- 0.059 after two months and to 0.11 +/- 0.06 after three months, all of them significantly different from basal values (p < 0.05). We found a relationship between ST decrease and the clinical response to antiandrogen therapy. On the basis of these results we suggest that ST values could be a good index for the follow-up of antiandrogen therapy in hirsute women.

Oxidative modification of lactate dehydrogenase by a non-enzymatic metal ion-catalyzed oxidation system

Exposure of lactate dehydrogenase from rabbit muscle to the Fe(III)/EDTA/ascorbate oxidation system leads to a time-dependent enzymatic inactivation (rate of inactivation of 7.35 x 10(-3) min-1), as well as to a spontaneous fragmentation of the protein. Fe(III) is the most important compound in this system, having the highest inactivating effects at concentrations above 10 microM. The substrate pyruvate and the products of the enzymatic reaction, when added at high concentration to the full mixture of the system, have a partial protective effect on the catalytic activity.

Inactivation of Phycomyces isocitrate lyase by thiol-reactive reagents. Evidence for an essential thiol group

Isocitrate lyase from the mycelium of Phycomyces blakesleeanus was inactivated with thiol-reactive reagents, 5,5'-dithiobis-(2-nitrobenzoic)acid, p-hydroxymercuribenzoic acid, N-ethylmaleimide or iodoacetate, at pH 6.8 and 25 degrees C. In all cases the inactivation is characterized by a biphasic kinetic profile. The rapid initial phase of inactivation does not increase linearly with increasing reagent concentration, but exhibits an apparent saturation effect, suggesting the formation of a reversible complex between the enzyme and the reagent prior to the inactivation step. Re-activation of the enzyme was observed under thiol excess treatment. The pH dependence of the initial phase of inactivation suggests that a group on the enzyme with pKa = 6.8 is being modified. The effect of ligands was tested on the inactivation reaction. Mg(2+)-Ds-isocitrate and Ds-isocitrate provided total protection, whereas Mg2+ ions, succinate and oxalate provided only partial protection of the enzyme against inactivation. On the basis of these results, we would suggest that the thiol-reactive reagents modify at least one thiol group crucial for the enzymatic activity and probably located in the interface between succinate and glyoxylate subsite.

Growth hormone response to thyrotropin-releasing hormone in acromegalic patients: reproducibility and dose-response study

The aim of the study was to analyze 14 consecutive patients with active acromegaly who had not undergone any therapy, the dose response of growth hormone (GH) to thyrotropin-releasing hormone (TRH), the existence of reproducibility of such response as well as to rule out the possibility of spontaneous fluctuations of GH which would mimic this response. On several nonconsecutive days, we investigated the GH response to saline serum, 100, 200 (twice) and 400 micrograms of TRH administration. We also studied both basal serum prolactin, serum prolactin after TRH administration and thyrotropin values. Our results show an absence of GH response after saline serum infusion, whereas after TRH doses, 36.3 42.8 and 45.4% positive responses were obtained, respectively. All GH responders were concordant to the different doses administered. The mean of GH concentrations of the different doses at different times did not reach significant differences. The response to the administration of the same dose brought about a significative increase, although it was not identical. It demonstrated a progressive increase of the area under the response curve, as did the means of increments after each TRH administration, albeit without reaching statistical significance. Between the GH-responding and GH-nonresponding groups there were no differences in either basal serum prolactin or serum prolactin and thyroid-stimulating hormone levels after TRH stimulation. The present study clearly shows that TRH elicits serum GH release from GH-secreting pituitary tumors. The response was reproducible in qualitative terms rather than quantitative, and no dose-response relationship was found between the TRH concentrations and the amounts of GH secreted.

High-dose chemotherapy with bone marrow rescue for treatment of Hodgkin's disease

Between December 1st 1984 and July 1st 1991, 20 patients, 11 males and 9 females, median age 36 years (range 14-54) with Hodgkin's disease were treated with high dose chemo-radiotherapy followed by autologous bone marrow rescue. At the time of autologous bone marrow transplantation, 8 patients were in complete remission, 9 in sensitive relapse and 3 were resistant to conventional treatments. There were 3 early procedure-related deaths: 1 cardiac failure due to cyclophosphamide treatment, 1 veno-occlusive disease, and 1 patient died from CMV interstitial pneumonitis, 4 months after ABMT. Of the 17 other patients, 15 are alive, 12 in complete remission, 2 in relapse and 1 patient is not evaluable due to short-follow-up follow-up. Disease free survival is 65% at 20 months with a follow-up of 60 months. There is a trend for a better disease-free survival in patients in complete remission at the time of autologous bone marrow transplantation vs patients in sensitive relapse, although it does not reach statistical significance (80% vs 37%).

Presenting features and prognosis of chronic lymphocytic leukemia in younger adults

We have analyzed 117 younger patients with chronic lymphocytic leukemia (CLL) (mean age, 44.5 years; SD, 4.8; range, 19 to 49; male/female ratio, 2.08) with three main objectives: (1) to see whether these patients have distinctive presenting clinical features; (2) to investigate the impact of the disease on survival; and (3) to analyze whether already well-known prognostic factors are also useful when applied to these patients. As compared with an older age population (greater than or equal to 50 years), there were no major differences in presenting features except for an increased proportion of males (2.08 v 1.21; P less than .025) and a higher hemoglobin level (13.47 +/- 2.70 g/dL v 12.84 +/- 2.77 g/dL; P less than .05) in the younger group. Median survival is 12.3 years (expected median from a control group, 31.2 years). Clinical stages, bone marrow patterns, blood lymphocyte counts, and its doubling time are all useful to separate different risk groups of patients. Whereas patients with favorable prognostic factors have a survival probability of about 80% 14 years after diagnosis, those with poor prognostic features have a median survival of less than 3 years. It is concluded that CLL in younger adults has no major distinctive presenting features and that known prognostic factors are useful to separate different risk groups of patients. These results should be of help in planning therapy for younger persons with CLL.

Age, sex and ICA influence on beta-cell secretion during the first year after the diagnosis of type 1 diabetes mellitus

We studied the independent influence of sex, age and islet-cell antibodies (ICA) on residual beta-cell secretion and metabolic control during the first year after the diagnosis of type 1 diabetes mellitus in 40 consecutive newly diagnosed patients. Glucagon-stimulated C-peptide secretion was measured after 5-10 days and 3, 6 and 12 months of diagnosis. ICA (JDF units) and complement-fixing ICA (CF-ICA) were determined at diagnosis and after 12 months. The influence of sex, age and ICA was analyzed in a multivariate analysis of variance of 3 factors (age, sex and ICA) for repeated measures over time. ICA and CF-ICA were positive in 75.0% and 35.0% of patients at diagnosis and in 48.7% and 20.5% of patients one year later. Persistence of ICA positivity was higher in females (p. less than 0.001) and in CF-ICA+ patients (p less than 0.01), but did not involve a different evolution of C-peptide secretion. Males had a lower C-peptide secretion than females (p = 0.023) during the first year after the diagnosis of type 1 diabetes, independently of the age and ICA status of the patients. Adult patients (greater than or equal to 18 years-old) had lower HbA1 values than younger patients (p = 0.006) and ICA+ patients with a moderate or high value (greater than 10 JDF units) had a lower C-peptide secretion over time (p = 0.031 at 6 months, p = 0.067 at 12 months) and higher HbA1 values (p = 0.056) than younger patients. HbA1 was significantly explained by ICA and C-peptide values in a stepwise multiple regression analysis (p = 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Mitochondrial F1-ATPase moiety from Phycomyces blakesleeanus: purification, characterization, and kinetic studies

Mitochondrial F1-ATPase was purified from the mycelium of Phycomyces blakesleeanus NRRL 1555(-) and its kinetic characteristics were studied. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the enzyme reveals five bands (alpha, beta, gamma, delta, and epsilon) characteristic of the F1 portion with apparent molecular weights of 60,000, 53,000, 31,000, 25,000, and 21,000, respectively. The molecular weight of the native F1-ATPase from Phycomyces blakesleeanus was in agreement with the stoichiometry alpha 3 beta 3 gamma delta epsilon. The MgATP complex is the true substrate for ATPase activity which has a Km value of 0.15 mM. High concentrations of free ATP or free Mg2+ ions inhibit the ATPase activity. ADP appears to act as a negative allosteric effector with regard to MgATP hydrolysis, with the apparent Vmax remaining unchanged.

Inhibition by excess of free ATP, and free Mg2+ ions of the mitochondrial F1-ATPase moiety from Phycomyces blakesleeanus

High concentrations of either Mg-ATP complex, free ATP, or free Mg2+ ions were inhibitors of the mitochondrial F1-ATPase moiety from Phycomyces blakesleeanus. Free Mg2+ acts as a linear competitive inhibitor with regard to Mg-ATP hydrolysis with a Ki value of 2.8 mM. The inhibition by free ATP was markedly biphasic and thus simple competitive inhibition alone is not sufficient to explain the inhibitory effect. From these results conclusions were drawn about the binding of the substrate, Mg-ATP complex, to the enzyme.

Thyroid stimulating antibodies in patients with Graves' ophthalmopathy

The possible pathogenetic role of thyroid stimulating antibodies (TSAb) was studied in 24 patients. The TSAb were measured by their ability to stimulate concentration of cAMP in human thyroid slices incubated in vitro with the immunoglobulins of these patients. The patients were divided in two groups: Group I, 16 patients with eye disease and hyperthyroidism and Group II, eight patients with eye disease but without hyperthyroidism. TSAb, were found to be high in 15 patients of the Group I (3.22 +/- 1.74 pmol cAMP/mg of wet tissue, mean +/- S.E.M.) whilst were normal in six patients of the Group II (0.98 +/- 0.53 pmol cAMP/mg of wet tissue, mean S.E.M.) (p < 0.001). These findings indicate that TSAb is not a marker of the Graves' ophthalmopathy and support the concept that hyperthyroidism and exophthalmos are two separate disorders.

[Pituitary apoplexy: analysis of endocrine function in 17 cases]

BACKGROUND

From a neurological standpoint, pituitary apoplexy (PA) is a well defined syndrome. There are few systematic studies addressing pituitary hormone secretion after a PA episode. The aim of the present study was to assess the frequency and degree of endocrine dysfunction due to PA.

METHODS

In 17 consecutive patients, the secretion of growth hormone (GH), the pituitary-adrenal axis status, thyrotropin (TSH), prolactin and gonadotropins (LH, FSH) were evaluated after the administration of insulin, thyrotropin releasing hormone (TRH) and gonadotropin-releasing hormone (LHRH) after an episode of PA. 20-90 days after surgery the measurements were repeated. Antidiuretic hormone (ADH) was measured by plasma/urine osmolality after water deprivation and, in some cases, by administration of hypertonic saline.

RESULTS

The most commonly found deficiency was that of GH (84%), which in two cases resulted in cure of acromegaly, followed by that of LH (78%). Pituitary-adrenal dysfunction was improved in two patients after surgery. In all cases except one there was a reduced secretion of at least two hormones. If serum prolactin was reduced, the rest of pituitary function was usually impaired. In one case, permanent diabetes insipidus developed after PA. The prevalence of PA in pituitary adenomas was 9%.

CONCLUSIONS

Pituitary hormone secretion after a PA episode is almost invariably impaired. This impairment may be reversed after surgery. Hypoprolactinemia is an indicator of pituitary hypofunction.

[Limitations of joint mobility in patients with type 1 diabetes mellitus]

BACKGROUND

To assess limitation of joint mobility in patients with type I diabetes mellitus and to evaluate its relation with retinopathy, joint mobility was prospectively assessed in 96 diabetic patients and 68 healthy controls.

METHODS

Joint mobility was explored with the praying maneuver and the measurement in mobility degrees of the third and fifth metacarpophalangeal joints, wrists and elbows. The degree of metabolic control was assessed with the mean glycosylated hemoglobin in the last two years. Retinopathy was investigated with direct funduscopy. The results were statistically evaluated with chi-square and Student's t tests and the linear coefficient.

RESULTS

A reduced joint mobility was found in 41 diabetics and 5 controls (p less than 0.0001). The reduction in joint mobility was related with the patients' age but not with the degree of metabolic control. 85% of diabetics with joint involvement had retinopathy of some degree.

CONCLUSIONS

A limited joint mobility is a common complication of type I diabetes mellitus. The demonstration of this abnormality in diabetic patients might represent a first and simple marker of microangiopathy.

Allogeneic bone marrow transplantation in chronic lymphocytic leukemia: 17 cases. Report from the EBMTG

Allogeneic bone marrow transplantation (BMT) was performed in 17 patients with chronic lymphocytic leukemia (CLL): 15 resistant and two untreated forms. There were 12 males and five females with a mean age of 40 years (32-49). The conditioning regimens and graft-versus-host disease (GVHD) prophylaxis varied. Successful engraftment was obtained in 15 evaluable cases. Lymphocytosis and clinical symptoms subsided in all but one case. All 15 evaluable patients developed acute GVHD. Among the 17 patients grafted, one early death was observed at the 15th day post-BMT, and one refractory patient died 2 months after BMT. Of the remaining 15 patients in complete remission (CR), four died from GVHD, hemorrhage and graft failure, and two relapsed at 7 and 54 months after BMT and died. Nine patients are alive in CR with a mean follow-up of 25.6 months (4-48). Chimerism was complete in eight patients and partial in the two T cell-depleted cases. In one case, an immunoglobulin gene rearrangement study showed no residual disease. These results suggest that allogenic BMT might be an alternative and possible curative therapy for refractory CLL in young patients when performed relatively early in the disease.

[Thyroid dysfunction induced by amiodarone in Catalonia. Prevalence and characteristics]

The purpose of this study was to review the epidemiological aspects and the characteristics of the thyroid disfunction produced by amiodarone in Catalonia, an area with type I endemic goiter. For this purpose, three groups of patients have been studied: 1) 102 patients with prolonged amiodarone treatment, out of whom 6 (5.9%) presented hyperthyroidism, and 2 (1.9%) hypothyroidism. 2) 909 patients with hyperthyroidism of any origin out of which 42 (4.6%) were produced by amiodarone. 3) 203 patients presenting primary hypothyroidism of any origin out of which 11 (3.8%) were induced by amiodarone. Out of the 48 patients with amiodarone induced hyperthyroidism, 16 presented multinodular goiter, 2 toxic thyroid goiter and 7 Graves Basedow disease. Thyroid uptake of 131I was studied in 10 cases being normal or increased in six of them, all with a underlaying thyroid pathology. Out of the 13 patients with amiodarone induced hypothyroidism, 3 presented diffuse goiter; thyroid uptake of 131I was studied in 5 patients, being normal or increased in 4 cases, 2 of which with thyroid pathology. Amiodarone administration very often produces thyroid disfunction, specially hyperthyroidism. These patients with hyperfunctional thyroids usually present underlying thyroid pathologies in which thyroid uptake of 131I are frequently not suppressed as well as in those patients in whide amiodarone induced hypothyroidism.

Hysteretic behaviour and GSSG substrate inhibition shown by glutathione reductase from Phycomyces blakesleeanus

Phycomyces blakesleeanus glutathione reductase shows hysteretic behaviour under experimental conditions, when GSSG substrate inhibition is observed. The progress curves for the reaction show an acceleration phase. The degree of hysteresis varied inversely as the enzyme concentration. It increased when GSSG or NADPH concentration increased, whereas the addition of GSH or NADP+ to the initial reaction mixture prevented it from occurring. In addition, hysteresis was dependent on pH, ionic strength and temperature, decreasing as any of these parameters increased. The parallel effects of pH and ionic strength on the GSSG substrate inhibition and hysteretic behaviour suggest a relationship between these two mechanisms. From the overall results reported in this paper, we propose that the hysteretic behaviour shown by Phycomyces glutathione reductase could be due to a process of time-dependent accumulation of reaction products rather than to a slow conformational change.

Isocitrate lyase from Phycomyces blakesleeanus. The role of Mg2+ ions, kinetics and evidence for two classes of modifiable thiol groups

Isocitrate lyase was purified from Phycomyces blakesleeanus N.R.R.L. 1555(-). The native enzyme has an Mr of 240,000. The enzyme appeared to be a tetramer with apparently identical subunits of Mr 62,000. The enzyme requires Mg2+ for activity, and the data suggest that the Mg2(+)-isocitrate complex is the true substrate and that Mg2+ ions act as a non-essential activator. The kinetic mechanism of the enzyme was investigated by using product and dead-end inhibitors of the cleavage and condensation reactions. The data indicated an ordered Uni Bi mechanism and the kinetic constants of the model were calculated. The spectrophotometric titration of thiol groups in Phycomyces isocitrate lyase with 5.5'-dithiobis-(2-nitrobenzoic acid) gave two free thiol groups per subunit of enzyme in the native state and three in the denatured state. The isocitrate lyase was completely inactivated by iodoacetate, with non-linear kinetics. The inactivation data suggest that the enzyme has two classes of modifiable thiol groups. The results are also in accord with the formation of a non-covalent enzyme-inhibitor complex before irreversible modification of the enzyme. Both the equilibrium constants for formation of the complex and the first-order rate constants for the irreversible modification step were determined. The partial protective effect of isocitrate and Mg2+ against iodoacetate inactivation was investigated in a preliminary form.

Clinical and pathologic studies of twenty-six patients with penetrating foreign body injury to the joints, bursae, and tendon sheaths

Foreign body synovitis has been neglected in the rheumatology literature. We describe 26 patients in whom arthritis, bursitis, or tenosynovitis appeared within 1 day to 7 years after an initial injury by a penetrating foreign body. Twenty-two patients presented with acute synovitis, which was followed by chronic or recurrent inflammation mimicking septic arthritis, osteomyelitis, monarticular juvenile rheumatoid arthritis, bone tumor, or apatite deposition disease. Foreign bodies were not seen in 5 inflammatory synovial fluids studied, but were seen in the synovium or periarticular tissues of 17 patients. Excisional biopsy was required in most patients for precise diagnosis and treatment.

[Peripheral T-cell lymphoma. Morphologic, immunophenotypic and immunogenotypic studies of 10 cases]

We describe the histopathology, immunophenotype and immunogenotype of 10 cases of peripheral T-cell lymphoma. The majority of patients showed disseminated disease at the time of diagnosis. From a histopathological view point the cases were classified into 5 types: T zone lymphoma (4 cases); Lennert lymphoma (2 cases); pleomorphic lymphoma, small all type (2 cases); pleomorphic lymphoma of medium-sized cell type (1 case); pleomorphic lymphoma of large cell type (1 case). In most of them the neoplastic cells demonstrated a mature T-cell phenotype: CD3+, CD4+, CD8-, CD43+, CD45RO+, CD45RA-, CD20- and surface immunoglobulins. All cases studied displayed gene rearrangements for the T-cell receptor beta chain while the immunoglobulins genes remained in germinal configuration. Antibodies against the human T-cell lymphotropic virus type I were not found in the 9 samples studied.

The influence of insulin antibodies on metabolic deterioration after interruption of continuous subcutaneous insulin infusion

To evaluate the influence of insulin antibodies (IA) on metabolic deterioration after interruption of continuous subcutaneous insulin infusion (CSII), we studied two groups of type I diabetic patients without residual insulin secretion: group 1 (5 patients) with insulin-binding antibodies below 10% and group 2 (8 patients) with insulin-binding antibodies above 10%. We investigated the changes in blood glucose, plasma non-esterified fatty acids (NEFA), bicarbonate and glucagon after stopping insulin infusion between 08.00 h. and 14.00 h. Insulin infusion cessation resulted in: 1) a similar increase in blood glucose in both groups after 2 hours of interruption (group 1: 9.45 +/- 1.28 mmol/L versus basal levels of 6.94 +/- 0.96 mmol/L, p less than 0.05; group 2: 8.11 +/- 2.87 mmol/L versus 5.75 +/- 2.17 mmol/L, p less than 0.02) and a greater increase in blood glucose in group 1 than group 2 after 4 hours (p less than 0.05) and after 6 hours (p less than 0.05); 2) a progressive increase in NEFA in group 1 throughout the study period (08.00 h.: 0.51 +/- 0.28 mmol/L; 14.00 h: 1.44 +/- 0.45 mmol/L, p less than 0.05) that was significant after 4 and 6 hours of CSII interruption; there were no changes in NEFA in group 2; 3) plasma level of IA correlated inversely with final glycemia (r = -0.67, p less than 0.01) and final NEFA (r = -0.56, p = 0.02). We conclude that IA may play a role in slowing metabolic deterioration after CSII interruption.

A study of the kinetic mechanism followed by glutathione reductase from mycelium of Phycomyces blakesleeanus

An investigation of the reaction mechanism of glutathione reductase isolated from the mycelium of Phycomyces blakesleeanus NRRL 1555(-) was conducted. The enzyme showed GSSG concentration-dependent substrate inhibition by NADPH and pH-dependent substrate inhibition by GSSG. At pH 7.5, the kinetic data were consistent with a basic scheme corresponding to the branching mechanism, involving a ping-pong with formation of a dead-end F.NADPH complex and an ordered sequential mechanism. Both pathways have in common the step in which NADPH binds to the free oxidized form (E) of the glutathione reductase. At low concentrations of GSSG the ping-pong mechanism prevails, whereas at high concentrations the ordered mechanism appears to dominate. The data were analyzed on the basis of the limiting ping-pong mechanism with F.NADPH complex formation and of the hybrid mechanism, and the kinetic constants of the model were calculated. The data obtained at acidic pH values do not rule out the possibility that the kinetic model may be more complicated than the basic scheme studied.

[Treatment of resistant or relapsing Hodgkin's disease with high doses of chemotherapy followed by autologous bone marrow transplant]

Eleven patients with Hodgkin's disease were treated with high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT). Four patients were resistant to initial therapy and 7 patients had relapsed but were progressing under second or third line therapy. The median time from initial diagnosis to transplantation was 44 months (range, 16 to 82). In 9 patients pre-ABMT consisted on high-dose CVB cyclophosphamide, etoposide and carmustine) chemotherapy, one patient was treated with BACT protocol (carmustine, cytosine arabinoside, cyclophosphamide and thioguanine) and other patient was treated with high-dose of busulfan and melphalan. In 8 patients complete remission (CR) was achieved, in one the remission was partial, one failed to respond and one case was not evaluable due to early death. Among CR patients, 2 died from late toxicity, and the other 6 remain in CR off therapy, one of them more than 33 months after ABMT. High-dose therapy produce severe myelosuppression in all patients. There were 3 treatment related death: one early death due to hemorrhagic myocarditis, one veno-occlusive disease of the liver and one due to cytomegalovirus sepsis. The high complete response rate in these heavily pretreated patients suggests that there may be an indication for high-dose therapy and ABMT in earlier resistant Hodgkin's disease. Moreover under such conditions, treatment related morbidity would be expected to be lower.

Different lymphocyte activity in patients with polycythaemia vera versus secondary polycythaemia and healthy blood donors

On comparing lymphocyte patterns in patients with polycythaemia vera (PV) versus healthy blood donors (NC) and patients with secondary polycythaemia (SP), we observed an altered CD4/CD8 ratio (p less than 0.01) mainly due to the decreased CD8 subpopulation in PV. We found an increased lymphocyte activity in PV patients when compared with both SP and NC: the interleukin 2 (IL-2) production was significantly higher (p less than 0.001) as was the lymphoproliferative response both to phytohaemagglutinin (p less than 0.001) and IL-2 (p less than 0.005). No significant differences were found between NC and SP. None of the PHA-stimulated PBMC samples from PV, SP or NC produced erythropoietin (EPO)-like or EPO-inhibitory activity. Our findings suggest an altered lymphoid lineage in PV patients.

Immunophenotype of blast cells in acute myelofibrosis

The immunophenotype of peripheral blood blast cells from six patients with acute myelofibrosis was studied using a panel of monoclonal antibodies directed against granulocytic, erythroid, megakaryocytic and lymphoid antigenic determinants. In all patients most of the blast cells were labeled with anti-HLA-DR and with the early myelomonocytic antibodies My7 (CD13), My9 (CD33) and B1-3C5 (CD34) (3/3). In three cases, platelet antibodies Edu3 (CD41) and GPIIIa (CD61) reacted with about 30% of blast cells. TdT was positive in two out of six samples studied. Lymphoid markers T3 (CD3), Leu9 (CD7), J5 (CD10), B4 (CD19) and B1 (CD20) were negative in all cases. These results suggest that blast cells are mainly of immature myelocytic origin. However, the coexistence of megakaryoblasts cannot be ruled out in the cases with a proportion of cells that are positive with Edu3 and GPIIIa antibodies.

ATP inhibition of Phycomyces pyruvate kinase: a kinetic study of the inhibitory effects on the allosteric kinetics shown by the enzyme

Studies on ATP effects on the allosteric kinetics shown by pyruvate kinase from Phycomyces blakesleeanus NRRL 1555 (-) are reported. Phosphoenolpyruvate showed an allosteric ATP-dependent substrate inhibition. The results supported the existence of spatially distinct catalytic binding sites and the inhibitory binding sites for phosphoenolpyruvate, and ATP showed opposite heterotropic effects with respect to these two types of binding site. With respect to Mg2+ ions, ATP caused a negative heterotropic effect. The global inhibitory effect of ATP was in agreement with the predictions postulated by the two-state concerted-symmetry model of Monod, Wyman and Changeux.

Transient hypothyroidism after iodine-131 treatment of Graves' disease

One hundred twenty six patients with Graves' disease, 26 with toxic multinodular goiter, and 18 with toxic adenoma were treated with 131I (3-15 mCi), and followed at monthly intervals for six months. Transient hypothyroidism occurred at two months in 22 patients with Graves' disease. In this state TSH levels became elevated in seven patients, but were normal or suppressed in seven. In 17 patients T4 and T3 levels returned to normal without T4 replacement. Five patients developed recurrent thyrotoxicosis, and required repeated doses of 131I. The possibility of transient hypothyroidism in the early months after 131I therapy in Graves' disease should be borne in mind.

Effect of glucose on isocitrate lyase in Phycomyces blakesleeanus

Repression of the synthesis of isocitrate lyase by glucose and/or induction of the synthesis of isocitrate lyase by acetate in Phycomyces blakesleeanus were demonstrated. Both glycerol and ethanol failed to induce isocitrate lyase activity. Furthermore, glucose appeared to cause an in vivo catabolite inactivation of the derepressed enzyme. Isocitrate lyase was inactivated both reversibly and irreversibly by glucose.

A kinetic study of the pH effect on the allosteric properties of pyruvate kinase from Phycomyces blakesleeanus

This paper reports the pH-dependence of the allosteric kinetics of Phycomyces blakeseeanus pyruvate kinase with phosphoenol pyruvate and Mg2+ ions in the presence and in the absence of fructose 1,6-bisphosphate (allosteric activator) and L-alanine (allosteric inhibitor). Hydrogen ions increase the affinity of the inhibitory binding sites for phosphoenol pyruvate and Mg2+ ions. Assuming partial conformational states of high and low affinity for inhibitory binding sites, the data presented are in good agreement with the predictions postulated by the two-state concerted-symmetry model of Monod, Wyman, and Changeux. Fructose-1,6-bisphosphate and L-alanine show opposite effects on the interactions of phosphoenol pyruvate and Mg2+ ions with their respective catalytic and inhibitory binding sites. At pH 6.0, the regulation of the Phycomyces pyruvate kinase activity by the concentrations of phosphoenol pyruvate and Mg2+ ions is controlled mainly by L-alanine.

Use of monoclonal anti-actin as a megakaryocyte marker in paraffin wax embedded bone marrow biopsy specimens

Monoclonal anti-actin was used as a marker of megakaryocytes in Zenker's fixed, paraffin wax embedded bone marrow tissue, using an immunoperoxidase staining method. Twenty bone marrow samples were studied, including controls, and different myeloproliferative and myelodysplastic syndromes. The results were compared with those obtained using factor VIII related antigen (F VIII RAg) immunolabelling. Anti-actin is as good a marker for megakaryocytes as anti-FVIIIRAg and is potentially clinically useful when morphological identification is difficult, when bone marrow aspiration is unsuccessful, or when quantitative evaluation of tissue sections is required.

Islet-cell antibodies: markers of a more severe insulin-dependent diabetes mellitus?

The aim of the present study was to analyze if an association exists between metabolic condition, C-peptide secretion and islet-cell antibody (ICA) presence in insulin-dependent diabetes mellitus (IDDM) at the clinical onset of the disease. Two hundred and nine IDDM patients were studied at diagnosis. 89% of the subjects showed residual C-peptide secretion that correlated inversely with blood glucose and glycosylated hemoglobin at diagnosis and with insulin requirement at discharge. Islet-cell antibodies were detected in 68.6% of the patients, complement-fixing ICA in 30% and insulin autoantibodies in 17.3%. Islet-cell antibody positive patients had a lower glucagon stimulated C-peptide than ICA negative subjects (0.41 +/- 0.22 versus 0.54 +/- 0.25 nmol/l, p = 0.005). However patients with high titers of ICA expressed in JDF units (JDF greater than 20) showed similar C-peptide secretion than ICA positive patients with a low level of JDF (JDF less than 20). When acid-base condition was analyzed patients on ketoacidosis at diagnosis had significant higher insulin requirement, lower C-peptide secretion and higher prevalence of ICA compared to patients that were not ketotic at diagnosis. Our findings suggest that residual beta-cell secretion plays a role on metabolic condition at diagnosis of IDDM and that ICA may be the markers of a more severe form of IDDM.

Non-secretory lambda multiple myeloma

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