Dual hormonal replacement therapy with insulin and recombinant human insulin-like growth factor (IGF)-I in insulin-dependent diabetes mellitus: effects on the growth hormone/IGF/IGF-binding protein system

Patients with insulin-dependent diabetes mellitus (IDDM) exhibit abnormalities in the GH/insulin-like growth factor (IGF) axis, including GH hypersecretion, low serum IGF-I and IGF-binding protein-3 (IGFBP-3) levels, and elevated IGFBP-1 levels. We recently demonstrated that in IDDM, dual hormonal replacement therapy with insulin plus recombinant human IGF-I (rhIGF-I) improves glycemic control better than insulin alone. To determine whether the addition of rhIGF-I therapy to insulin therapy also corrects GH/IGF/ IGFBP abnormalities, we examined the effects of chronic combined rhIGF-I/insulin therapy on key components of the somatotropin axis. Forty-three pediatric IDDM patients were randomly assigned to groups receiving daily, fasting subcutaneous injections of placebo or rhIGF-I (80 micrograms.kg.day) for 28 days, while continuing to receive splitmix insulin therapy and intensive outpatient management. rhIGF-I therapy corrected IGF-I deficiency, suppressed IGFBP-1 levels (P < 0.01), and induced a trend toward lower circulating GH levels throughout the study. rhIGF-I therapy also induced an approximate 50% decrease in IGF-II levels (P < 0.001) and an approximate 70% increase in IGFBP-2 levels (P < 0.05). Serum IGFBP-3 levels, normal before treatment, remained normal during rhIGF-I administration. All effects were apparent during the first week of rhIGF-I therapy and persisted throughout treatment. Because improvements in the GH/ IGF axis abnormalities and in glycemic control were greater in subjects receiving combined rhIGF-I and insulin, these data strongly support the concept that dual hormonal replacement in IDDM may offer distinct therapeutic advantages over insulin monotherapy.

Dual hormonal replacement with insulin and recombinant human insulin-like growth factor I in IDDM. Effects on glycemic control, IGF-I levels, and safety profile

OBJECTIVE

To examine if dual replacement with insulin and rhIGF-I, recombinant human insulin-like growth factor I (rhIGF-I) may be safe and result in improved metabolic control and reduced insulin usage.

RESEARCH DESIGN AND METHODS

Forty-three patients with IDDM were randomized to receive a daily injection of rhIGF-I (80 mcg/kg s.c.) or placebo while on conventional insulin therapy for 4 weeks. Insulin was adjusted in the attempt to achieve predetermined goal glycemic values. Free and total IGF-I, four daily blood glucoses, and HbA1c were measured.

RESULTS

Before randomization, placebo and rhIGF-I groups exhibited low plasma levels of free and total IGF-I, which increased toward normal levels during the treatment period only in the rhIGF group. The regression curve obtained from the average of daily blood glucose measurements indicated that the glycemic profile, overlapping in the lead-in period, exhibited a downward trend in the rhIGF-I group during the treatment period. Mean blood glucose level during the last 10 days of treatment was lower in the rhIGF-I groups (174 +/- 37 vs. 194 +/- 32 mg/dl). HbA1c level was reduced by more than one-half percent more in the rhIGF-I group (-1.85%) than in the control group (-1.3%). The dose of regular insulin was significantly lower in the rhIGF-I group (0.2 +/- 0.1 vs. 0.28 +/- 0.1 U. kg-1. 10 days-1 in the placebo group; P < 0.05).

CONCLUSIONS

rhIGF-I in combination with conventional insulin treatment ameliorated the low plasma total and free IGF-I levels and was well tolerated in IDDM. There was a trend toward improved glycemic control, while the regular insulin dose was significantly decreased.

Depression, delusions, and hallucinations in Alzheimer's disease: no relationship to apolipoprotein E genotype

The apolipoprotein E (APOE) locus on chromosome 19 has been shown to modify risk, and age at onset, of Alzheimer's disease (AD). The authors hypothesized that the phenotypic expression of different psychiatric symptoms in patients with AD would be associated with variability in APOE locus. Neuropsychiatric and genetic testing of 120 probable AD patients revealed 28% had major depression, 17% had minor depression, 30% had delusions, and 14% had hallucinations; 69% were carriers of at least one APOE E4 allele (14% homozygous E4/E4, 49% heterozygous E3/E4, 6% heterozygous E2/E4, 29% homozygous E3/E3, 2% heterozygous E2/E3). Prevalence of the various psychiatric disturbances did not differ significantly in AD patients with different APOE genotypes. Apolipoprotein E does not appear to modify the risk of developing AD-associated psychiatric symptomatology.

A new use for focus groups--building and empowering a culturally diverse team

BACKGROUND

The success of a cultural diversity training program in an acute care health facility was due in large part to the use of the focus group method.

METHOD

This method enabled us to identify sensitive issues to be addressed in educational programs for staff. Some of the criteria for successful use of the focus group method applied to our situation.

RESULT

We found that much of the traditional wisdom did not necessarily apply in a diversity program.

CONCLUSION

Several additional benefits such as ethnic group empowerment and the enhancement of a more team-oriented approach made use of the focus group method a very worthwhile venture for this project.

Children's methods of coping with stress: a twin study of genetic and environmental influences

The relative importance of environmental and hereditary factors in how children cope with stress was examined. Emotion-focused, problem-focused, and additional coping variables were assessed in 44 monozygotic (MZ) and 30 dizygotic (DZ) twin pairs, aged 9-16 years. The effects of heritability, shared environment, and unshared environment were examined in structural modelling analyses. Genetic factors accounted for a majority of the reliable variance in four of seven coping variables, while effects of twins' shared environment were negligible for all but one coping variable. Environmental factors important to individual differences in coping strategies were primarily unique to each child (unshared between the twins), highlighting the importance of individual experiences in shaping coping behaviors.

Identification and antitumor activity of a reduction product in the murine metabolism of pyrazoloacridine (NSC-366140)

PURPOSE

Pyrazoloacridine (PZA) is a newly developed anticancer agent currently undergoing clinical trials. Its mode of action has not been elucidated but the presence in its chemical structure of a 5-nitro functional group and its activity against oxygen-deficient cancerous cells argue in favor of enzymatic nitro reduction as a possible pathway for its antitumor activity. In order to assess the involvement of the nitro functionality in PZA activity, as well as to determine other metabolic products, a pharmacological and chemical study of PZA was designed.

METHODS

Urine and stool samples were collected from mice before and after treatment with PZA. Samples were fractionated using chromatographic methods and then evaluated using mass spectrometry (MS). One of the characterized metabolites was synthesized and tested in vitro and in vivo for anticancer activity.

RESULTS

One major fraction from mouse stool was initially characterized by MS as the 5-aminopyrazoloacridine (5-APZ). This compound was chemically synthesized by catalytic hydrogenation of PZA was stabilized as the hydrochloride salt. 5-APZ was marginally cytotoxic in vitro and was inactive in vivo against a tumor cured by PZA (Panc 03).

CONCLUSIONS

Bioreduction of the nitro group to an amine compound from PZA represents a pathway in the metabolic sequence of PZA. The inactivity of the chemically generated amine product does not provide conclusive evidence that this pathway is not involved in the cytotoxicity of PZA because other intermediates in the nitro reduction pathway may have a role in the activity of PZA. In particular, the hydroxylamine derivative of PZA could give answers to the involvement of this pathway in PZA cytotoxicity.

Diabetes mellitus affects prostaglandin E2 levels in mouse embryos during neurulation

The arachidonic acid cascade leading to prostaglandins has been implicated in diabetic embryopathy. Both arachidonic acid and prostaglandin E2 reverse the teratogenic effects of high glucose concentrations on neural tube development in mouse embryos in culture. Arachidonic acid supplementation also protects against diabetes-induced neural tube defects in vivo. In the present study, prostaglandin E2 was measured directly in embryos from normal and diabetic mice. In normal mice a clear developmental pattern was seen. Prostaglandin E2 levels were high during early formation of the cranial neural folds (day 8), declined during convergence and fusion of the cranial neural folds to form the neural tube (day 9), and were low after neurulation was complete (days 10 and 11). In addition, evidence in this study indicates that embryos have cyclooxygenase activity capable of generating prostaglandin E2 during a brief developmental period preceding neural tube closure. In embryos from mice made diabetic (> 13.9 mmol/l glucose) with streptozotocin, prostaglandin E2 levels were significantly lower than normal during early development of the cranial neural folds (day 8), but similar to normal after the cranial neural tube had closed (late day 9 and day 10). The findings suggest that diabetes mellitus, as ascertained by high blood glucose, promotes cranial neural tube malformations by causing a functional deficiency of prostaglandin E2 during early neurulation. Whether the altered PGE2 pattern in the embryo indicates a diabetic effect on the arachidonic acid-prostaglandin cascade in cells of the embryo or in cells of extraembryonic or maternal tissues is uncertain.

p120 Ras GTPase-activating protein interacts with Ras-GTP through specific conserved residues

Previous structural studies of RasGAP have failed to clearly localize sites of Ras interaction to individual amino acids. Hypothesizing that sites of interaction with Ras-GTP would be conserved, 11 of the most highly conserved amino acid residues of RasGAP were changed by mutation. Each mutant protein was purified as a glutathione S-transferase catalytic domain fusion and analyzed for protein stability, Ras GTPase stimulating activity, affinity for Ras-GTP, and when possible, secondary structure. The majority of conserved positions were found to be important structurally but with no direct role in Ras interactions. However, Arg786, Lys831, and Arg925 were observed to be essential for binding to Ras-GTP but not for protein structure. RasGAP residues 890-902 (block 3A) were observed to be homologous to residues 1540-1552 of the yeast adenylyl cyclase with amino acid substitutions in both regions resulting in increased affinity for Ras. This is the first example of a conserved Ras interaction motif in distinct Ras effector proteins. Our data are supportive of a model for GAP/Ras-GTP association in which the conserved, positively charged Arg786, Lys831, and Arg925 residues form salt bridges with the conserved, negatively charged residues in the Ras effector loop.

Social contact, social attitudes, and twin similarity

The nature of the relationship between social contact and attitude similarly between twins was investigated using longitudinal data from a sample of Australian twins. Earlier research has suggested that social attitudes are not explained solely by shared environment; rather there are both genetic and environmental components that explain variance in social attitudes. Using three types of analyses we investigated the magnitude of the relationship and the direction of causation between attitude similarity and social contact. Longitudinal analysis of within-pair variance by level of contact suggests that attitude similarity leads to contact among the females and that similarity is both genetically and environmentally based. Analyses using a crosslag regression model suggest that similarity causes contact among MZ females. Biometrical analyses indicate differences in direction of causation for males and females. Among females, both genetic and shared environmental parameter estimates could be equated across contact groups, suggesting little relationship between contact and similarity. Among males, findings of smaller estimated heritability in the high-contact group suggest that similarity causes contact. However, an increased estimate of the contribution of shared environmental variance in the high-contact males could additionally suggest that contact leads to similarity.

Critical care of the patient with hematologic malignancy

Patients with leukemia, lymphoma, or multiple myeloma are prone to critical illness because of the diffuse nature of their disease and the disruption of protective mechanisms. Despite high morbidity rates, a number of these patients have an excellent probability of long-term remission if supported through a crisis. Complications that cause critical illness can be categorized as related to disease or those caused by therapy. Those with unique features or management strategies for the hematologic malignancy patient and are included in this discussion include: leukostasis, disseminated intravascular coagulation, tumor lysis syndrome, respiratory failure, and typhlitis. A case study of an acutely ill, newly diagnosed patient with several of these oncologic emergencies is used to exemplify typical clinical finds and management strategies.

Selective trafficking of KNOTTED1 homeodomain protein and its mRNA through plasmodesmata

Plasmodesmata are intercellular organelles in plants that establish cytoplasmic continuity between neighboring cells. Microinjection studies showed that plasmodesmata facilitate the cell-to-cell transport of a plant-encoded transcription factor, KNOTTED1 (KN1). KN1 can also mediate the selective plasmodesmal trafficking of kn1 sense RNA. The emerging picture of plant development suggests that cell fate is determined at least in part by supracellular controls responding to cellular position as well as lineage. One of the mechanisms that enables the necessary intercellular communication appears to involve transfer of informational molecules (proteins and RNA) through plasmodesmata.

Physician-patient communication in managed care

The quality of physician-patient communication affects important health care outcomes. Managed care presents a number of challenges to physician-patient communication, including shorter visits, decreased continuity, and lower levels of trust. Good communication skills can help physicians create and maintain healthy relationships with patients in the face of these challenges. We describe 5 communication dilemmas that are common in managed care and review possible solutions suggested by recent literature on physician-patient communication. We also describe ways that managed care plans can promote more effective communication between physicians and patients.

Phase I clinical trial of pyrazoloacridine NSC366140 (PD115934)

The pyrazoloacridine (PZA) analogue NSC366140 (PD115934) entered clinical trial based on unique preclinical characteristics including solid tumor selectivity in vitro, marked antitumor activity in vivo against murine solid tumors, selectivity against noncycling cells, and activity against multidrug-resistant tumor cells. After identification of the pre-clinical efficacy and an acceptable toxicity profile, a Phase I study of PZA was carried out. A total of 28 patients was entered and received a total of 67 treatment courses. The drug was administered via a 1-h infusion every 21 days. The starting dose was 30 mg/m2 with 2-fold dose escalations through 480 mg/m2. The next dose escalation was 50%, to 720 mg/m2. Grade I through grade IV toxicities were observed. Since no dose-limiting toxicities were observed at 480 mg/m2, and up to grade IV toxicities were observed at 720 mg/m2, an intermediate dose, 600 mg/m2, was evaluated. Dose-limiting toxicities at 720 mg/m2 were hematological (grade III and IV neutropenia) in four of six patients and neurological (up to grade III cerebral toxicities, including restlessness, dizziness, agitation/anxiety, personality changes, and nightmares, as well as myoclonus) in three of six patients treated. The pharmacokinetic parameters which helped predict these toxicities included area under the curve and peak plasma level. Pharmacokinetic studies showed interpatient variations in all parameters studied. The mean area under the curve levels of PZA at the highest two dose levels in patients were near the level detected in mice at their maximum tolerated total dose. The recommended starting dose for Phase II trials using this schedule is 600 mg/m2.

Impaired glucose tolerance and increased weight gain in transgenic rats overexpressing a non-insulin-responsive phosphoenolpyruvate carboxykinase gene

The effects of an overexpressed, non-insulin-responsive gluconeogenic enzyme, phosphoenolpyruvate carboxykinase (GTP) (PEPCK; EC 4.1.1.32), on glucose homeostasis were investigated. Transgenic rats harboring a metallothionein-driven PEPCK gene (lacking the entire PEPCK upstream-regulatory region) expressed transgene PEPCK mRNA in the key gluconeogenic tissues, liver and kidney. Female transgenic rats, studied at 10 weeks of age, showed mild fasting hyperglycemia (6.9 +/- 0.2 vs. 5.9 +/- 0.1 mM P = 0.002 n = 6), hyperinsulinemia (92.2 +/- 4.0 vs. 54.0 +/- 6.6 pM, P = 0.001, n = 6), impaired glucose tolerance and increased weight gain (178.3 +/- 3.2 vs. 153.4 +/- 2.5 g, P = 0.001, n = 16 and n = 13 transgenic and control rats, respectively). Despite hyperinsulinemia at this age, kidneys of transgenic rats maintained a significant 20% elevation of total PEPCK enzyme activity, while total liver PEPCK activity was not reduced. This study suggests that an insulin-resistant step in the gluconeogenic pathway can lead to glucose intolerance and an increase in weight. These rats offer the unique opportunity to study the metabolic consequences of chronic, mild excess glucose supply, as seen in non-insulin-dependent diabetes.

Carotid steal syndrome: a case study

The progression of subclavian arterial stenosis and the subsequent formation of collateral pathways serve to alter the pressure gradients in subclavian steal syndrome, altering ipsilateral vertebral artery flow from its normal state to "latent," "transient," and "continuous" steals. A similar altered flow in the carotid arteries can be observed with stenosis of the proximal common or innominate artery. A 59-year-old man was seen in the vascular laboratory for evaluation of symptomatic peripheral arterial disease. An incidental asymptomatic stenosis of the right innominate and left proximal subclavian artery was found. Further cerebral vascular evaluation displayed a continuous right subclavian steal and a latent steal in the right internal carotid artery. Transcranial Doppler examination displayed "transient" steal in the terminal right internal carotid artery. Combining duplex and transcranial Doppler evaluations allows sequential evaluation of the progression of arterial disease and its effect on the flow patterns in the cerebral vasculature.

Human fructose-1,6-bisphosphatase gene (FBP1): exon-intron organization, localization to chromosome bands 9q22.2-q22.3, and mutation screening in subjects with fructose-1,6-bisphosphatase deficiency

Fructose-1,6-bisphosphatase (EC 3.1.3.11) is a key regulatory enzyme of gluconeogenesis that catalyzes the hydrolysis of fructose-1,6-bisphosphate to generate fructose-6-phosphate and inorganic phosphate. Deficiency of fructose-1,6-bisphosphatase is associated with fasting hypoglycemia and metabolic acidosis because of impaired gluconeogenesis. We have cloned and characterized the human liver fructose-1,6-bisphosphatase gene (FBP1). FBP1, localized to chromosome bands 9q22.2-q22.3 by fluorescence in situ hybridization, consists of seven exons that span > 31 kb, and the six introns are in the same position as in the rat gene. FBP1 was screened for mutations in two subjects with fructose-1,6-bisphosphatase deficiency. Four nucleotide substitutions were identified, two of which were silent mutations in the codons for Ala-216 (GCT-->GCC) and Gly-319 (GGG-->GGA). The other substitutions were in intron 3, a C-->T substitution 7 nucleotides downstream from the splice donor site, and in the promoter region, an A-->T substitution 188 nucleotides upstream from the start of transcription. These nucleotide substitutions were also found in normal unaffected subjects and thus are not the cause of fructose-1,6-bisphosphatase deficiency in the two subjects studied. The molecular basis of hepatic fructose-1,6-bisphosphatase deficiency in these subjects remains undetermined but could result from unidentified mutations in the promoter that decrease expression or from mutations in another gene that indirectly lead to decreased fructose-1,6-bisphosphatase activity.

Diabetes-like renal glomerular disease in Fanconi-Bickel syndrome

The Fanconi-Bickel syndrome is a rare inherited disorder of metabolism characterized by hepatic glyconeogenesis, galactose intolerance, renal Fanconi syndrome with nephromegaly, and glycogen accumulation in proximal renal tubular cells. An 8-year-old patient with this disease and severe rickets due to medically resistant hypophosphatemia was found to have the previously unrecognized complication of renal glomerular hyperfiltration, microalbuminuria, and diffuse glomerular mesangial expansion. Similar to patients with glucose-6-phosphatase deficiency, the glomerular disease in this patient resembles incipient diabetic nephropathy. The Fanconi syndrome may be due to the defective transport of glucose at the proximal tubular basolateral membrane, which results in accumulation of glucose and secondarily glycogen within tubular cells. Since the metabolic defect, as evidenced by glycogen accumulation, selectively involves proximal renal tubular cells in the kidney of patients with Fanconi-Bickel syndrome and glucose-6-phosphatase deficiency, the abnormalities in renal glomerular hemodynamics and mesangial construct in these rare diseases are likely due to renal tubular factors, if the mechanism originates in the kidney. A delineation of these phenomena may further our understanding of the pathogenesis of diabetic nephropathy.

"Is this man your daddy?" suggestibility in children's eyewitness identification of a family member

Studies of natural language development suggest that overextension of family memberships terms, such as daddy or papa, occurs in children in the second year of life, but rarely persists thereafter. However, in British Courts it is common for the testimony of 3- and even 4-year-olds to be dismissed on the grounds that these children may not be reliably identifying their father or stepfather when they claim that daddy was the perpetrator of abuse. This study examined whether 3-year-olds could be persuaded to confirm that a stranger who was labelled as daddy was their own father. A mock interview with experienced disclosure interviewers was conducted. Five of the 17 children--all from blue-collar families--misidentified a photograph of their own father when an identification question was repeated. Rather than undermining the validity of all preschoolers testimony, it is suggested that the responses of some children to apparently mundane questions of fact are influenced by contextual factors, including repetition of the question and the perceived omniscience of the interviewer.

Twin-twin transfusion syndrome: intraamniotic pressure measurement in the assessment of volume reduction at serial amniocenteses

Two cases of severe twin-twin transfusion syndrome are described. In both, serial amniocenteses were followed by resolution of the disordered inter-twin haemodynamics with 4 intact term survivors. In all reports to date of aggressive reduction with or without successful outcome, volume reduction has been dictated by subjective or semiquantitative ultrasonic estimates of liquor volume. With the use of intraamniotic pressure estimation we describe a more rational basis for the removal of these large volumes of amniotic fluid.