Lithium induced changes in intracellular free magnesium concentration in isolated rat ventricular myocytes

We have examined the effect of exposing isolated rat ventricular myocytes to lithium while measuring cytosolic free magnesium ([Mg2+]i) and calcium ([Ca2+]i) levels with the fluorescent, ion sensitive probes mag-fura-2 and fura-2. There was a significant rise in [Mg2+]i after a 5 min exposure to a solution in which 50% of the sodium had been replaced by Li+, but not when the sodium had been replaced by bis-dimethylammonium (BDA). However, there were significant increases in [Ca2+]i when either Na+ substitute was used. The possibility that Li+, which enters the cells, interferes with the signal from mag-fura-2 was eliminated as Li+ concentrations up to 10 mM had no effect on the dye's fluorescence signal. A possible explanation for these findings is that Li+ displaces Mg2+ from intracellular binding sites. Having considered the binding constants for Mg2+ and Li+ to ATP, we conclude that Li+ can displace Mg2+ from Mg-ATP, thus causing a rise in [Mg2+]i. This work has implications for other studies where Li+ is used as a Na+ substitute.

Risk factors for detecting germline BRCA1 and BRCA2 founder mutations in Ashkenazi Jewish women with breast or ovarian cancer

We ascertained 184 Ashkenazi Jewish women with breast/ovarian cancer (171 breast and 13 ovarian cancers, two of the former also had ovarian cancer) in a self-referral study. They were tested for germline founder mutations in BRCA1 (185delAG, 5382insC, 188del11) and BRCA2 (6174delT). Personal/family histories were correlated with mutation status. Logistic regression was used to develop a model to predict those breast cancer cases likely to be germline BRCA1/BRCA2 mutation carriers in this population. The most important factors were age at diagnosis, personal/family history of ovarian cancer, or breast cancer diagnosed before 60 years in a first degree relative. A total of 15.8% of breast cancer cases, one of 13 ovarian cancer cases (7.7%), and both cases with ovarian and breast cancer carried one of the founder mutations. Age at diagnosis in carriers (44.6 years) was significantly lower than in non-carriers (52.1 years) (p<0.001), and was slightly lower in BRCA1 than BRCA2 carriers. Thirty three percent of carriers had no family history of breast or ovarian cancer in first or second degree relatives. Conversely, 12% of non-mutation carriers had strong family histories, with both a first and a second degree relative diagnosed with breast or ovarian cancer. The predicted values from the logistic model can be used to define criteria for identifying Ashkenazi Jewish women with breast cancer who are at high risk of carrying BRCA1 and BRCA2 mutations. The following criteria would identify those at approximately 10% risk: (1) breast cancer <50 years, (2) breast cancer <60 years with a first degree relative with breast cancer <60 years, or (3) breast cancer <70 years and a first or second degree relative with ovarian cancer.

Teaching medical mycology in the year 2000

Medical mycology is of increasing interest to the basic scientist, pathologist, microbiologist and clinician. This interest has been prompted by the rising number of immunosuppressed patients with opportunistic fungal infections, the expanding boundaries of the so-called endemic mycoses, the recognition of several major new endemic mycoses and a variety of other emerging fungal infections, and the development of potent, non-toxic antifungal drugs to treat these infections. The world of mycology is changing dramatically, especially in developing countries which have only limited resources to cope with the impact of the compromised host and the introduction of costly new antifungal drugs. Consequently, there is an urgent need to increase our effectiveness as teachers of medical mycology at all levels and in all regions of the world.

Pediatric renal transplantation under tacrolimus-based immunosuppression

BACKGROUND

Tacrolimus has been used as a primary immunosuppressive agent in adult and pediatric renal transplant recipients, with reasonable outcomes. Methods. Between December 14, 1989 and December 31, 1996, 82 pediatric renal transplantations alone were performed under tacrolimus-based immunosuppression without induction anti-lymphocyte antibody therapy. Patients undergoing concomitant or prior liver and/or intestinal transplantation were not included in the analysis. The mean recipient age was 10.6+/-5.2 years (range: 0.7-17.9). Eighteen (22%) cases were repeat transplantations, and 6 (7%) were in patients with panel-reactive antibody levels over 40%. Thirty-four (41%) cases were with living donors, and 48 (59%) were with cadaveric donors. The mean donor age was 27.3+/-14.6 years (range: 0.7-50), and the mean cold ischemia time in the cadaveric cases was 26.5+/-8.8 hr. The mean number of HLA matches and mismatches was 2.8+/-1.2 and 2.9+/-1.3; there were five (6%) O-Ag mismatches. The mean follow-up was 4.0+/-0.2 years.

RESULTS

The 1- and 4-year actuarial patient survival was 99% and 94%. The 1- and 4-year actuarial graft survival was 98% and 84%. The mean serum creatinine was 1.1+/-0.5 mg/dl, and the corresponding calculated creatinine clearance was 88+/-25 ml/min/1.73 m2. A total of 66% of successfully transplanted patients were withdrawn from prednisone. In children who were withdrawn from steroids, the mean standard deviation height scores (Z-score) at the time of transplantation and at 1 and 4 years were -2.3+/-2.0, -1.7+/-1.0, and +0.36+/-1.5. Eighty-six percent of successfully transplanted patients were not taking anti-hypertensive medications. The incidence of acute rejection was 44%; between December 1989 and December 1993, it was 63%, and between January 1994 and December 1996, it was 23% (P=0.0003). The incidence of steroid-resistant rejection was 5%. The incidence of delayed graft function was 5%, and 2% of patients required dialysis within 1 week of transplantation. The incidence of cytomegalovirus was 13%; between December 1989 and December 1992, it was 17%, and between January 1993 and December 1996, it was 12%. The incidence of early Epstein-Barr virus-related posttransplant lymphoproliferative disorder (PTLD) was 9%; between December 1989 and December 1992, it was 17%, and between January 1993 and December 1996, it was 4%. All of the early PTLD cases were treated successfully with temporary cessation of immunosuppression and institution of antiviral therapy, without patient or graft loss.

CONCLUSIONS

These data demonstrate the short- and medium-term efficacy of tacrolimus-based immunosuppression in pediatric renal transplant recipients, with reasonable patient and graft survival, routine achievement of steroid and anti-hypertensive medication withdrawal, gratifying increases in growth, and, with further experience, a decreasing incidence of both rejection and PTLD.

Comparison of one week of oral terbinafine (250 mg/day) with four weeks of treatment with clotrimazole 1% cream in interdigital tinea pedis

Treatment of interdigital tinea pedis often involves long-term therapy with topically applied preparations. Effective oral preparations, such as the allylamine terbinafine (Lamisil), taken over a shorter period, could provide a useful therapeutic alternative. A total of 269 patients from five centres with clinically diagnosed interdigital tinea pedis were entered into this double-blind, randomized, double-dummy, parallel-group study comparing oral terbinafine 250 mg once daily for 1 week with 1% clotrimazole (Canesten) cream applied twice daily for 4 weeks. Of these, 137 patients were evaluable for efficacy (confirmed dermatophyte infection by microscopy and culture): 63 terbinafine and 74 clotrimazole. At week 4, the mycological cure rates (negative culture at week 1 and negative results on microscopy and culture at week 4 onwards) were very similar (71% for clotrimazole and 72% for terbinafine). There was a faster response rate in the terbinafine group with respect to signs and symptoms at week 1. Both treatments were equally well tolerated; adverse events occurred equally in the two groups. In conclusion, oral terbinafine in a single daily dose of 250 mg for 1 week is as effective and as well tolerated as 1% clotrimazole cream applied twice daily for 4 weeks in the treatment of interdigital tinea pedis.

Urinary measurement of transforming growth factor-beta and type IV collagen as new markers of renal injury: application in diabetic nephropathy

Urinary samples were concentrated rapidly and efficiently and were used to develop several protein assays that may be of value in monitoring individuals with progressive renal disorders. Transforming growth factor-beta1 (TGF-11) and retinol binding protein (RBP) were measured with modification of commercially available methods used to assay serum specimens; type 3 collagen (T3C) was measured with a new immunonephelometric assay. The precision characteristics of these assays are comparable with those reported for microalbuminuria. The clinical utility of measuring a panel of these markers was demonstrated in urine samples from 16 control subjects and from 46 individuals with insulin-dependent diabetes mellitus (IDDM) with various albumin excretion rates (AERs). TGF-beta1 and T3C were used as markers of cytokine expression and of the renal fibrogenic process, whereas RBP excretion served as a marker of tubular injury or dysfunction. Compared with controls, T3C excretion was significantly increased in 18 normoalbuminuric and further increased in 13 microalbuminuric (AER 20 < or = 200 microg/min) IDDM subjects. RBP excretion was increased in macroalbuminuric IDDM subjects (AER >200 microg/min, overt nephropathy). Significant correlations were also found between AER and RBP in all but macroalbuminuric individuals, whereas TGF-beta1 correlated with T3C excretion in controls and in normoalbuminuric diabetic subjects. Urinary RBP but not AER was an excellent predictor of diabetic nephropathy as defined by serum creatinine (P = 0.0001). This underscores the importance of an early tubulopathy in the subsequent development of glomerulopathy and overt nephropathy. The data suggest that longitudinal monitoring of a panel of urinary markers such as that used in the current study may better define their relevance in progressive glomerulosclerosis and may also provide greater insight into the mechanisms underlying such process.

Identification of missense and truncating mutations in the BRCA1 gene in sporadic and familial breast and ovarian cancer

The cloning of the breast and ovarian cancer susceptibility gene, BRCA1, allows direct estimation of the proportion of these cancers in the general population which can be attributed to germline mutations in this gene. We have used a combination of SSCP, heteroduplex analysis, and chemical cleavage of mismatch to screen the BRCA1 gene for mutations in the germline of 42 patients with breast or ovarian cancer who either have a moderate family history of these cancers, or have no family history of malignancy but a very early onset of the disease. A total of 30 sequence variants were observed, eight of which have not been described previously. Three sequence changes detected by chemical cleavage or heteroduplex analysis were missed by SSCP. The variants included 13 missense mutations, which were assessed for their pathogenic implications. Two of these (M18T and A1708E) are nonconservative substitutions which are located in evolutionarily conserved regions of the gene: M18T lies just upstream of the RING finger motif, and A1708E abolishes the transcriptional transactivation activity of the carboxy-terminal region of BRCA1. Mutations were observed in eight patients overall (19.0%), and protein-truncating mutations occurred in five of 27 (18.5%) families with 1-3 cases of breast or ovarian cancer. The data suggest that a significant proportion of patients with a modest or no family history of these cancers may carry germline mutations in BRCA1.

Aortic and renal artery thrombosis in a neonate: recovery with thrombolytic therapy

This report describes a neonate with acute renal failure associated with extensive aortic and bilateral renal artery thrombosis attributed to inadequate breastfeeding and severe dehydration. Dialytic and general supportive care, together with concurrent anticoagulation, and continuous aggressive intrathrombic instillation of urokinase for 5 days resulted in near-complete thrombolysis. Renal functional recovery began 11 days after the onset of anuria. Despite ischemic atrophy of the left kidney, renal function and blood pressure were normal on follow-up. Thus, in neonates thrombolytic therapy may positively impact survival and recovery of renal function even in the setting of prolonged ischemic renal injury.

Cumulative glycemic exposure and microvascular complications in insulin-dependent diabetes mellitus. The glycemic threshold revisited

BACKGROUND

The development of microvascular insulin-dependent diabetes mellitus (IDDM) complications has been shown to be related to both duration of diabetes and the degree of glycemic exposure. However, controversy exists as to whether there is a threshold of glycemic exposure, below which there is minimal risk. Furthermore, there are few data describing the relationship of total glycemic exposure (duration x degree) to complications rates-a potentially useful research and clinical tool.

OBJECTIVES

To determine a cumulative glycemic exposure variable that combines the effect of both degree and duration of hyperglycemia and to evaluate this variable in terms of its relation to microvascular complications. The association between cumulative glycemic exposure and complication risk was also examined to evaluate whether there was a threshold effect.

METHODS

A total of 353 patients with IDDM who had completed the first 6 years of follow-up in the Pittsburgh Epidemiology of Diabetes Complications Study were included in this analysis. These subjects had a mean age of 27.9 years, and the mean duration of the disease was 19.4 years. Subjects were examined at baseline (cycle 1) and then biennially (cycle 2, cycle 3, and cycle 4) for diabetes complications. Total glycosylated hemoglobin (HbA1) was measured at each cycle. A cumulative glycemic exposure variable, named A1months, was calculated by multiplying the number of HbA1 units above normal at each cycle by the number of months between the midpoints of the preceding and succeeding cycle intervals.

RESULTS

The mean number of A1months experienced at the time of diagnosis of proliferative retinopathy (914), microalbuminuria (952), overt nephropathy (1043), and distal symmetrical polyneuropathy (1043) did not vary by duration of diabetes. Thus, approximately 1000 A1months were needed (on average) for the advanced complications to develop. Although the risk for developing proliferative retinopathy rose gradually as A1months increased, a more abrupt increase in the risk was seen (again at approximately 1000 A1months) for microalbuminuria (odds ratio, 6.9; 95% confidence interval, 2.5-19.1), overt nephropathy (odds ratio, 6.5; 95% confidence interval, 2.0-21.7), and distal symmetrical polyneuropathy (odds ratio, 6.5; 95% confidence interval, 2.4-17.8). Nonetheless, complications developed in the majority of cases at glycemic exposures below 1000 A1months. The cumulative glycemic exposure variable A1months does not predict complications any better than its component variables (duration and HbA1). Furthermore, formal statistical testing failed to show a definitive threshold for any complication.

CONCLUSIONS

Although A1months does not enhance prediction of complications, it may be a useful summary measure of glycemic exposure for both patients and physicians. However, although subjects with 1000 A1months or more appear to be at increased risk of developing most microvascular complications, because the majority of complications arise in subjects with less than this exposure, this threshold value should only be considered a minimal goal. For example, our data suggest that for most microvascular complications to develop, it would take, on average, 83 years with an HbA1 unit at 1% above normal, 42 years at 2% above normal, 28 years at 3% above normal. 21 years at 4% above normal, and 18 years at 5% above normal.

Do tissue plasminogen activator-plasminogen activator inhibitor-1 complexes relate to the complications of insulin-dependent diabetes mellitus? Pittsburgh Epidemiology of Diabetes Complications Study

The purpose of this study was to examine the potential relationship of tissue plasminogen activator-plasminogen activator inhibitor-1 (tPA-PAI-1) complexes and diabetic complications in individuals with insulin-dependent diabetes mellitus (IDDM). To address this issue, data from the third follow-up visit of participants in the Epidemiology of Diabetes Complications (EDC) study were examined. There were 454 participants, aged 32 +/- 8 years, with duration of IDDM of 23 +/- 8 years. Higher levels of tPA-PAI-1 complexes were seen for both men and women with IDDM complications. Specifically, statistically significant differences were seen in men with neuropathy (1.81 +/- 0.9 versus 1.42 +/- 0.8 ng/mL, p < 0.01), microalbuminuria (1.77 +/- 1.1 versus 1.35 +/- 0.6 ng/mL, p < 0.01), retinopathy (1.67 +/- 0.9 versus 1.43 +/- 0.8 ng/mL, p < 0.05), and lower extremity arterial disease (1.93 +/- 0.7 versus 1.50 +/- 0.9 ng/mL, p < 0.05) versus men without the particular complication. In women, higher complex levels were shown for those with retinopathy (1.51 +/- 0.8 versus 1.29 +/- 1.1 ng/mL, p < 0.01). Potential mechanisms for the relationship of higher complex levels and diabetic complications include an altered fibrinolytic response and/or insulin resistance. Because the results are cross sectional, it cannot be established whether the higher concentration of complexes is a result of the presence of complications or are antecedent. Prospective follow-up will be required to determine if tPA-PAI-1 complexes are predictive of the development of IDDM complications.

Thalidomide: a novel therapy for microsporidiosis

BACKGROUND & AIMS

Microsporidiosis is a common cause of chronic diarrhea in human immunodeficiency virus (HIV)-seropositive individuals and often does not respond to treatment. Fecal tumor necrosis factor alpha (TNF-alpha) is elevated in microsporidiosis; therefore, thalidomide, an anti-TNF-alpha agent, was used as therapy.

METHODS

Eighteen subjects with chronic diarrhea caused by Enterocytozoon bieneusi that had not responded symptomatically to albendazole and 1 untreated subject with Encephalitozoon intestinalis received 1 month of thalidomide, 100 mg nocte. Clinical response was assessed by stool frequency and body weight, histological response by light microscopy with villus height/crypt depth ratios and electron microscopy, and immunologic response by fecal TNF-alpha level.

RESULTS

Seven subjects with chronic diarrhea due to E. bieneusi had a complete clinical response, and 3 had a partial response to thalidomide. There was a significant decrease in stool frequency from 5.3 to 3.1 per day (P = 0.001), and weight increased significantly by 1.2 kg (P < 0.02). Thalidomide significantly increased the villus height/crypt depth ratio (1.95 to 2.07; P = 0.045) and number of abnormal forms of microsporidia (P < 0.01). Fecal TNF-alpha level nonsignificantly decreased from 17.9 to 8.9 U/mL. There was apparent disruption of all stages of the life cycle of E. intestinalis.

CONCLUSIONS

Thalidomide may be an effective therapy for diarrhea and weight loss from E. bieneusi.

The Arabidopsis NIM1 protein shows homology to the mammalian transcription factor inhibitor I kappa B

The NIM1 (for noninducible immunity) gene product is involved in the signal transduction cascade leading to both systemic acquired resistance (SAR) and gene-for-gene disease resistance in Arabidopsis. We have isolated and characterized five new alleles of nim1 that show a range of phenotypes from weakly impaired in chemically induced pathogenesis-related protein-1 gene expression and fungal resistance to very strongly blocked. We have isolated the NIM1 gene by using a map-based cloning procedure. Interestingly, the NIM1 protein shows sequence homology to the mammalian signal transduction factor I kappa B subclass alpha. NF-kappa B/I kappa B signaling pathways are implicated in disease resistance responses in a range of organisms from Drosophila to mammals, suggesting that the SAR signaling pathway in plants is representative of an ancient and ubiquitous defense mechanism in higher organisms.

The Arabidopsis NIM1 protein shows homology to the mammalian transcription factor inhibitor I kappa B

The NIM1 (for noninducible immunity) gene product is involved in the signal transduction cascade leading to both systemic acquired resistance (SAR) and gene-for-gene disease resistance in Arabidopsis. We have isolated and characterized five new alleles of nim1 that show a range of phenotypes from weakly impaired in chemically induced pathogenesis-related protein-1 gene expression and fungal resistance to very strongly blocked. We have isolated the NIM1 gene by using a map-based cloning procedure. Interestingly, the NIM1 protein shows sequence homology to the mammalian signal transduction factor I kappa B subclass alpha. NF-kappa B/I kappa B signaling pathways are implicated in disease resistance responses in a range of organisms from Drosophila to mammals, suggesting that the SAR signaling pathway in plants is representative of an ancient and ubiquitous defense mechanism in higher organisms.

Hereditary demyelinating neuropathy of infancy. A genetically complex syndrome

Nine cases are described of a demyelinating peripheral neuropathy that had an onset in infancy. The clinical features conformed to those of type III hereditary motor and sensory neuropathy or Dejerine-Sottas disease. All showed a severe neurological deficit and had profoundly reduced nerve conduction velocities. Amongst these cases we identified four novel point mutations in the peripheral myelin protein 22 (PMP22) gene. These were Ser72Trp, Ser76lle and Leu80Pro. The Ser72Trp mutation was dominantly inherited by a mother and son, both severely affected. Two novel mutations in the gene for P0 myelin protein were also detected. These were Ile134Thr in exon 3, and a complex rearrangement in exon 4. The remaining three patients had presumed autosomal recessive inheritance. In these, no abnormality for the PMP22 and P0 genes was detected and a mutation at another locus or loci seems probable. On nerve biopsy the final two cases were shown to be examples of hereditary neuropathy with focally folded myelin sheaths. One showed both bulbar and diaphragmatic involvement. It is concluded that hereditary demyelinating neuropathy of infancy is genetically heterogeneous. Mutational screening for the PMP22 and P0 genes and nerve biopsy are therefore merited in patients with a childhood demyelinating neuropathy that is more severe than usual and in whom a chromosome 17 duplication is not present.

Estrangement, interventions, and male violence toward female partners

The primary objective of this paper is to integrate three relatively distinct lines of research on male violence towards intimate female partners. First, the relation between conjugal violence and estrangement is examined. We found them to be positively associated, but they can vary independently. Second, we examined the association between estrangement and interventions. Estrangement was found to be associated with private, private/public and mainly public interventions depending upon the level of estrangement. High levels of estrangement are strongly but not invariably associated with ending the relationship. Third, we reviewed the link between interventions and violence. Interventions which empower battered female partners are most effective in ending male partner violence. Taken together, the findings tend not to support hypotheses derived from the theory of male proprietariness. Implications for social policy are discussed in the final segment.

Tacrolimus in pediatric renal transplantation

Tacrolimus was used as the primary immunosuppressive agent in 69 pediatric renal transplantations between December 17, 1989, and June 30, 1995. Children undergoing concomitant or prior liver and/or intestinal transplantation were excluded from analysis. The mean recipient age was 10.3+/-5.0 years (range, 0.7-17.5 years). Seventeen (24.6%) children were undergoing retransplantation, and six (8.7%) had a panel reactive antibody level of 40% or higher. Thirty-nine (57%) cases were with cadaveric kidneys, and 30 (43%) were with living donors. The mean donor age was 28.0+/-14.7 years (range, 1.0-50.0 years), and the mean cold ischemia time for the cadaveric kidneys was 27.0+/-9.4 hr. The antigen match was 2.7+/-1.2, and the mismatch was 3.1+/-1.2. All patients received tacrolimus and steroids, without antibody induction, and 26% received azathioprine as well. The mean follow-up was 32+/-20 months. One- and 4-year actuarial patient survival rates were 100% and 95%. One- and 4-year actuarial graft survival rates were 99% and 85%. The mean serum creatinine level was 1.2+/-0.8 mg/dl, and the calculated creatinine clearance was 82+/-26 ml/min/1.73 m2. The mean tacrolimus dose was 0.22+/-0.14 mg/ kg/day, and the level was 9.5+/-4.8 ng/ml. The mean prednisone dose was 2.1+/-4.9 mg/day (0.07+/-0.17 mg/kg/day), and 73% of successfully transplanted children were off prednisone. Seventy-nine percent were not taking any antihypertensive medications. The mean serum cholesterol level was 158+/-54 mg/dl. The incidence of delayed graft function was 4.3%. The incidence of rejection was 49%, and the incidence of steroid-resistant rejection was 6%. The incidence of rejection decreased to 27% in the most recent 26 cases (January 1994 through June 1995). The incidence of new-onset diabetes was 10.1%; six of the seven affected children were able to be weaned off insulin. The incidence of cytomegalovirus disease was 13%, and that of posttransplant lymphoproliferative disorder was 10%; the incidence of posttransplant lymphoproliferative disorder in the last 40 transplants was 5% (two cases). All of the children who developed posttransplant lymphoproliferative disorder are alive and have functioning allografts. Based on this data, we believe that tacrolimus is a superior immunosuppressive agent in pediatric renal transplant patients, with excellent short- and medium-term patient and graft survival, an ability to withdraw steroids in the majority of patients, and, with more experience, a decreasing rate of rejection and viral complications.