Scanning electron microscopic study of the surface finish of the round sections of preformed arches of NiTi (orthodontic wires made of nickel/titanium

The authors indicate the advantageous characteristics of NiTi wire, focusing the attention on finishing surface accuracy. Every surface damage can become the start of a fracture.     

Kinetics and mechanism of the interaction between human serum albumin and monomeric haemin

Previous studies showed hyperre-sponsiveness to human growth hormone (hGH) in men with myotonic or limb girdle dystrophies (MMD or LGD). Because polyamines may mediate some actions of hGH, we have now investigated polyamine metabolism in these and other dystrophies. Under metabolic balance study conditions, serum and urine levels of putrescine (Pu), spermidine (Sd), spermine (Sm), and cadaverine (Cd) were measured in six normal men (36-44 yr), four men with MMD (38-44 yr), and three men with LGD (30-36 yr), before and during treatment with 0.532 U/kg body wt ((3/4)/d) of hGH. Daily balances of N, P, and K were also monitored. In the normal subjects, hGH did not influence elemental balances or serum and urine polyamines. In MMD, hGH caused significant retention of N, P, and K (P < 0.005). Basal levels of Sm and Cd were significantly elevated above normal (P < 0.005), and Pu, Sm, and Cd increased two- to fourfold above basal during hGH treatment (P < 0.005). In LGD, hGH also caused retention of N, P, and K. Basal levels of nearly all the polyamines (not serum Pu) were significantly above normal in serum and urine (P < 0.05). During hGH treatment, all four polyamines rose significantly above basal (P < 0.005). Serum and urine polyamine levels in five boys with Duchenne muscular dystrophy, age 8-13, did not differ from those in five age-matched normal boys. Skeletal muscle polyamines were measured in five men (31-40 yr) without muscle disease and in three men with LGD (30-38 yr). Average concentrations of Pu, Sd, Sm, and Cd were 46, 306, 548, and 61 nmol/g wet wt in LGD and 1, 121, 245, and 14 in the normal subjects, respectively (P < 0.05 in each instance). Polyamines were determined in skeletal muscle, liver, kidney, and brain of male mice with hereditary muscular dystrophy and in age- and sex-matched normal controls. Pu, Sd, Sm, and Cd levels were two to three times higher than normal in muscle, but did not differ in liver, kidney, and brain. Similar findings were made in male hamsters with hereditary dystrophy and in their controls. The abnormality in hamster muscle polyamines appeared between 1 and 6 wk of age and persisted or intensified until 30 wk. These data reveal abnormalities of polyamine metabolism in men with MMD, in men with LGD, and in mice or hamsters with hereditary muscular dystrophy. The polyamine disorder could be related to dystrophic patients' hyperresponsiveness to hGH.     

Socio-familial characteristics of black male heroin addicts and their nonaddicted friends

To determine whether family, peer, and school variables are associated with divergent heroin-use patterns or career outcomes, we interviewed 183 black male heroin addicts, experimenters, and non-heroin users from Chicago's south side. While subgroup differences on socio-familial variables generally were not statistically significant, we did observe a number of trends in the expected direction. For example, addicts were more likely than experimenters or nonusers to come from broken homes, to have friends who were involved in serious types of drug use and other illegal activities, and to drop out of high school. At the same time, the pervasiveness of some of our measures of "social disharmony" across the sample suggest that, at least in some inner-city black neighborhoods, these patterns are perhaps becoming the norm.     

Clozapine in the treatment of a young adolescent with schizophrenia

Although recent reports have suggested that clozapine may be efficacious in the treatment of adolescents with schizophrenia, few studies have examined the use of clozapine in patients younger than 17 years of age. We describe highly successful trials of clozapine conducted in a 13-year-old girl and her cousin, both of whom developed severe symptoms of schizophrenia, which were refractory to neuroleptic medication, at the ages of 11 and 13 years, respectively. The pharmacology of and clinical experience with clozapine are reviewed.     

Adult vaccination

Experience with a urological waiting list initiative is presented, wherein a list of 231 non-urgent cases was cleared over a 5 month period by a single operator. Some patients had waited 10 years for surgery. Following a postal request, the waiting list was validated; 31.2% of patients wished to be removed. The remaining 68.8% desired surgery and consisted of 51 requiring minor surgical procedures and 108 who needed more major surgery mostly for the relief of bladder outflow obstruction. Minor cases received dates for surgery; however, only 68.2% of this group attended despite being given more than one date for admission. Major cases were reviewed in a pre-admission clinic. General and urological condition was assessed, improved where necessary and surgery booked or delayed accordingly. A small number of patients did not attend or only attended to be reassured that surgery was not needed. Following clinical review, 18.5% of this group did not require operation. The long urological waiting list is a unique situation where patients listed may no longer require surgery. Reviewing these patients not only reduces numbers but also markedly increases percentage attendance for surgery.     

Long-term effect of lovastatin on lipoprotein profile in patients with primary nephrotic syndrome

Eight patients with biopsy-proven primary nephrotic syndrome were included in an open, prospective, two-year study of lovastatin. One patients was withdrawn after 6 months due to an asymptomatic rise in creatinine phosphokinase, which was rapidly reversed after interruption of lovastatin. In the remaining patients, treatment was well-tolerated and produced no side effects. After 2 years of treatment, these 7 patients had decreases in total cholesterol from 446 +/- 165 to 250 +/- 57 mg/dl (p < 0.001), LDL cholesterol from 343 +/- 121 to 174 +/- 49 mg/dl (p < 0.001), Apo B lipoprotein from 162 +/- 60 to 108 +/- 42 mg/dl (p < 0.05), triglycerides from 336 +/- 273 to 182 +/- 71 mg/dl (p < 0.04). There was no change in HDL cholesterol. The LDL/HDL cholesterol and the total/HDL cholesterol ratios fell from 15.0 +/- 12.1 and 19.1 +/- 17.2 mg/dl before the study to 4.4 +/- 1.2 and 6.3 +/- 1.6 mg/dl, respectively, at 2 years. A decrease in proteinuria from 8.6 +/- 4.6 to 5.0 +/- 3.7 g/24 h (p < 0.02) was noted in 4 patients on concomitant ACE inhibitor therapy. Renal function remained stable in all patients throughout the study, except for one whose moderate impairment progressed to end-stage renal failure requiring dialysis 3 months poststudy. We conclude that long-term lovastatin in patients with primary nephrotic syndrome is an effective and generally safe treatment for accompanying dyslipidemia.     

Chromogranin A(210-301) is the major form of pancreastatin-like material in human gut extracts and endocrine tumors

A radioimmunoassay of human pancreastatin was developed using a rabbit antiserum that selectively recognized the C-terminal amidated end of the peptide, and it was used for the identification of the molecular forms of pancreastatin in human gut (stomach, duodenum, small intestine, colon) and endocrine tumor extracts (liver metastasis of a gastrinoma and a medullary carcinoma of thyroid, one nonsecreting pancreatic tumor, one recurrence of a gut carcinoid, one vipoma and one insulinoma). In all gut extracts, a gel filtration chromatography revealed the presence of three peaks of pancreastatin-like immunoreactivity. The predominant form eluted with an apparent molecular weight higher than that of pancreastatin. This form was also predominant in the endocrine tumors analyzed, except in the insulinoma, where a lower molecular weight form predominated. The high molecular form was further purified from a liver metastasis of a gastrinoma. The pancreastatin-like immunoreactivity eluted in all the chromatographical systems (reverse-phase, ion exchange) as a single peak that was finally purified to homogeneity and sequenced. The sequence of the first 29 N-terminal amino acids was obtained unambiguously and corresponded to the sequence 210-238 of chromogranin A. Considering the selectivity of the assay used for peptide identification, this major form was identified as the fragment 210-301 of chromogranin A. It is likely that the predominant form of pancreastatin in human gut extracts and noninsular tumors is a 92 amino acid peptide.     

Clinical applications of fusion imaging in oncology

Recent developments in tumor imaging, made possible by advances in instrumentation and radiopharmaceuticals, has led to an increasing need for accurate anatomic correlation of single photon emission computed tomography (SPECT) and positron emission tomography (PET) images. Fusion imaging permits the functional strengths of SPECT and PET to be combined with the anatomic resolution of computed tomography (CT) and magnetic resonance imaging (MRI). Clinical applications of fusion imaging include the evaluation of brain tumors, lymphoma, hepatic lesions and monoclonal antibody studies. The continued development of these techniques will eventually allow fusion imaging to become a routine part of nuclear medicine practice.