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P C O'Brien

Publications and source records attributed to P C O'Brien.

At least 127 records · Page 7Linked to original sources
PubMed1997

A phase III double-blind randomised study of rectal sucralfate suspension in the prevention of acute radiation proctitis.

BACKGROUND AND PURPOSE: A limited number of studies have suggested that oral sucralfate reduces the acute and late gastro-intestinal side-effects of pelvic radiotherapy and sucralfate enemas ameliorate symptoms of chronic proctitis. Sucralfate may act via local bFGF at the mucosal level in promoting angiogenesis and reducing epithelial associated microvascular injury. This multi-institutional study was designed to test the hypothesis that sucralfate given as an enema would have a significant protective effect against acute radiation induced rectal injury by direct application to the mucosa. MATERIALS AND METHODS: Eighty-six patients having radiotherapy for localised carcinoma of the prostate were randomised in a double-blind placebo-controlled study to receive either 15 ml of placebo suspension or 3 g of sucralfate in 15 ml suspension, given as a once daily enema during and for 2 weeks following radiotherapy. Assessment was based on the EORTC/RTOG acute toxicity criteria and a patient self-assessment diary. RESULTS: There was no significant difference between placebo and sucralfate for peak incidences of EORTC/RTOG proctitis. For the placebo and sucralfate arms 95 and 88% (difference 7 +/- 11%) suffered some degree of proctitis, with 71 and 61% (difference 10 +/- 19%) reaching grade 2, respectively. The median period to onset of grade 2 proctitis was 33.5 and 36 days, with the median duration being 9.5 and 15 days, respectively, again these difference being non-significant. Thirty-five and 37% of patients rated the effect of radiotherapy on bowel habit as 'a lot' with a moderate or severe effect on normal daily living in 52 and 49%, respectively. CONCLUSION: This study suggests that sucralfate given as a once daily enema does not substantially reduce the incidence of symptoms associated with acute radiation proctitis and its routine clinical use cannot be recommended. This cohort of patients will be followed to determine if any difference develops in relation to late toxicity.

Acute Disease↗
PubMed1997

Assessing changes over time in temporal lobectomy: outcome by scoring seizure frequency.

Current methods of evaluating seizure outcome after anterior temporal lobectomy (ATL) have major limitations. We evaluated the usefulness of a recently proposed system in our study of the stability of seizure frequency after ATL in 184 patients with intractable epilepsy. Data collection by chart review was supplemented by an intensive program of follow-up by our survey research center through correspondence or phone calls according to a protocol approved by our Institutional Review Board. Seizure frequency during each 12-month period after ATL was scored for each patient. The only statistically significant change in seizure frequency scores during follow-up was between the third and the fourth years (means of 2.61 and 2.11; P < 0.045). Further assessment showed that the change was most likely due to an increase in the proportion of patients who achieved a score of 0 when they successfully stopped taking antiepileptic medications (9.1% in the third year and 22.5% in the fourth year; P < 0.05). There was no statistically significant difference between follow-up years in the proportion of patients achieving excellent outcome (i.e. scores of 0-4). Outcome remained unchanged when follow-up at each year was confined to the same patients throughout their postsurgical course. By using the Seizure Frequency Scoring System, we have demonstrated that seizure outcome remains stable after ATL. The scoring system facilitates the detection of subtle changes in the postoperative course. The advantages and the limitations of the system are discussed.

Adult↗
PubMed1997

Risk of Alzheimer's disease among elderly patients with anemia: population-based investigations in Olmsted County, Minnesota.

PURPOSE: To evaluate the association, if any, between Alzheimer's disease (AD) and anemia among the elderly. METHODS: Both case-control and cohort methodologies were used to evaluate this association. The case-control study included all incident cases of AD whose onset occurred during 1980-1984 in Rochester, MN (n = 302). An age- and gender-matched control was selected from among Rochester residents seen for care at Mayo Clinic during the year of onset of the case. All community medical records for cases and controls were reviewed to identify women with hemoglobin levels of < 12 g/dL and men with hemoglobin levels of < 13 g/dL during the year of onset and the prior year for cases and during the index year and year prior for controls. Logistic regression was used to estimate odds ratios (OR). The retrospective cohort study used the 618 residents of Olmsted County, MN, who were > or = 65 years of age and whose anemia, as defined above, was newly recognized in 1986. Standardized incidence ratios (SIR) for AD were estimated by use of the person-years of follow-up in the cohort and the incidence rates of AD for this community. RESULTS: In the case-control study, an almost twofold increase in occurrence of AD was associated with anemia (OR, 1.88; 95% CI, 1.17-3.03). For men and women, respectively, the ORs were 1.81 (95% CI, 0.75-4.39) and 1.96 (95% CI, 1.11-3.47). The cohort study showed no overall increase in risk of AD (SIR, 0.98; 95% CI, 0.67-1.37). For men, the SIR was a comparable 1.49 (95% CI, 0.79-2.56), whereas for women the SIR was only 0.79 (95% CI, 0.49-1.23). CONCLUSIONS: Although anemia may be a risk factor for AD in the elderly, the mechanism by which anemia contributes to the pathogenesis of AD or to the unmasking of AD symptoms is unknown.

Aged↗
PubMed1997

Isolation of chromosome-specific paints from high-resolution flow karyotypes of the sheep (Ovis aries).

High-resolution bivariate flow karyotypes were obtained using fibroblast cell lines from a sheep with a normal karyotype (2n = 54), from sheep carrying Robertsonian translocation chromosomes and from sheep-hamster somatic cell hybrids. By taking advantage of the presence of chromosome polymorphisms, translocation chromosomes and sheep-hamster somatic cell hybrids, all sheep chromosomes were isolated by flow sorting. Chromosome-specific paints were generated from each sorted peak using degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR). The sheep chromosome present in each peak was identified by chromosome-specific microsatellite analysis of the DOP-PCR products and fluorescence in situ hybridization (FISH) onto DAPI-banded sheep metaphase chromosomes. The chromosome-specific DNA obtained in this study can be used for the production of genomic libraries and as a resource for mapping randomly cloned DNA sequences that will greatly aid the construction of genetic and physical maps in the sheep. The chromosome-specific paints will facilitate chromosome identification and contribute to the study of karyotype evolution in the sheep and related species.

Animals↗
PubMed1997

A reappraisal of the tandem fusion theory of karyotype evolution in Indian muntjac using chromosome painting.

We have tested the tandem fusion hypothesis of the origin of the Indian muntjac karyotype (2n = 6/7) by using reciprocal chromosome painting between the Indian muntjac, Chinese muntjac (n = 46) and brown brocket deer (2n = 70 + 3B) with chromosome-specific paint probes derived from flow-sorted chromosomes of these three deer species. Our results have shown that the euchromatic blocks of all chromosome arms of the brown brocket deer have been conserved apparently unchanged in number and content in the Indian muntjac. While confirming the conservation in toto of most of Chinese muntjac euchromatin in the karyotype of the Indian muntjac, we demonstrate that the synteny of chromosomes 1, 2, 3, 4 and 5 of the Chinese muntjac has been disrupted by chromosome rearrangements other than fusions. This indicates that the present karyotype of the Indian muntjac cannot be reconstructed from the hypothetical Chinese muntjac-like 2n = 46 ancestral karyotype exclusively by chromosome fusions. Furthermore, we have shown that the breakpoints of these rearrangements appear to have occurred near to the fusion points formed during the origin of the 2n = 46 karyotype of the Chinese muntjac from a 2n = 70 karyotype, which is believed to be ancestral for the family Cervidae. Moreover, we substantiate that on the Indian muntjac chromosomes, the C5 probe, which is derived from the centromeric satellite sequences of the Chinese muntjac, maps to the putative fusion points determined by comparative chromosome painting and presumably represents the remnants of ancestral centromeric sequences.

Animals↗
PubMed1997

No evidence for axonal atrophy in human diabetic polyneuropathy.

In rats with streptozin-induced diabetes mellitus, the caliber of distal myelinated fiber (MF) axons in relation to the number of myelin lamellae is smaller than in controls. This finding usually has been attributed to axonal atrophy, but shrinkage or maldevelopment has also been considered. For human diabetic polyneuropathy (DP), axonal atrophy has been assumed by some investigators, but convincing evidence has not been demonstrated. We morphometrically evaluated transverse sections of 33 sural nerves from carefully evaluated diabetic patients > or = 30 years old without (8 patients) or with (25 patients) DP and compared them with 24 nerves from healthy subjects > or = 30 years old. Nerves from diabetic patients and controls were obtained under identical conditions and processed and evaluated in the same way, using an observer blind to the disease condition. Using computer digitization of electron micrographs, we evaluated the axonal area, perimeter, index of circularity, number of myelin lamellae, and frequency of adaxonal sequestration of 50.4 (mean) +/- 5.8 (SD) MF per sural nerve for healthy subjects and diabetic patients > or = 30 years old. The regression lines of the natural log (In) of axonal area on number of myelin lamellae of diabetic patients (with or without DP) were not significantly different from the regression lines of nerves of healthy subjects for large MFs-the most reliable group in which to recognize atrophy. Likewise, the regression lines of index of circularity (IC) (an index that is decreased with atrophy or shrinkage) on number of myelin lamellae for large fibers was not significantly different between the disease and control groups. The rate of adaxonal sequestration was not significantly higher in DP than in healthy subjects. These results do not support the hypothesis that axonal atrophy occurs in human DP. For small MF, or all MF, some significant differences in regression lines of In axonal area or IC on number of lamellae were found, but these changes are probably explained by events of remyelination and axonal regeneration, which can affect these relationships and are known to occur in DP.

Adult↗
PubMed1997

Factors associated with work outcome after anterior temporal lobectomy for intractable epilepsy.

PURPOSE: Whereas the effect of anterior temporal lobectomy on seizure frequency is well recognized, less is known about its impact on work status. METHODS: One hundred thirty-four of 190 consecutive patients with temporal lobectomy participated in this study. Eligibility criteria were developed to ensure that only patients with the potential of achieving specific outcomes were included in the corresponding analyses. RESULTS: After surgery, significantly more patients were independent in activities of daily living (p < 0.001) or able to drive (p < 0.001). Income from work also increased (p < 0.01). Nearly one fifth of the patients who were eligible for analysis had either a gain (8%) or a loss (11%) of full- or of part-time work. Univariate analyses revealed the following factors to be associated with full-time work after surgery: student or full-time work within a year before surgery, full-time work experience before surgery, full- or part-time employment experience before surgery, no disability benefits before surgery, low postsurgical seizure frequency, improved postsurgical seizure control, excellent postsurgical seizure control, driving after surgery, and further education after surgery (p < 0.05). Significant factors on multivariate analysis were being a student or having full-time work within a year before surgery [odds ratio, 16.2 (95% CI, 4.3-60.5)], driving after surgery [15.2 (3.2-72.0)], and obtaining further education after surgery [9.2 (2.2-53.0)]. CONCLUSIONS: Anterior temporal lobectomy for intractable epilepsy improves activities of daily living and the ability to drive. Work outcome of this surgery is influenced by presurgical work experience, successful postsurgical seizure control especially to allow driving, and obtaining further education after surgery.

Activities of Daily Living↗
PubMed1997

Hippocampal transverse relaxation times in patients with Alzheimer disease.

PURPOSE: To determine whether hippocampal relaxation times in magnetic resonance (MR) imaging differ between patients with probable Alzheimer disease and elderly control subjects with normal cognition. MATERIALS AND METHODS: MR imaging relaxation times were measured in the head and body of the right and left hippocampi in 123 subjects: 62 patients with Alzheimer disease (44 women, 18 men; age range, 65-89 years) and 61 elderly control subjects without cognitive impairment (39 women, 22 men; age range, 65-89 years). Hippocampal relaxation times were correlated with clinical status (patient vs control subject), age, sex, laterality (right vs left), and location within the hippocampus (body vs head). The hippocampal T2 value was correlated with the severity of disease in the patients. RESULTS: No statistically significant difference in the relaxation times was found between the two clinical groups for the analysis of the right versus left hippocampi and the hippocampal head versus body. In both patients and control subjects, no correlation was found between T2 measurements and age or sex. Twenty-seven patients had a clinical dementia rating (CDR) score of 0.5 (very mild dementia), 21 patients had a CDR score of 1.0 (mild dementia), and eight patients had a CDR score of 2.0 (moderate dementia). The CDR score was not available in six patients. No statistically significant association between T2 values and severity of disease was observed. CONCLUSION: MR relaxation time measurements in the hippocampus are not useful for the detection of Alzheimer disease.

Aged↗
PubMed1997

Evolution of the black muntjac (Muntiacus crinifrons) karyotype revealed by comparative chromosome painting.

The black muntjac (Muntiacus crinifrons) has an unusual karyotype of 2n = 8 in females and 2n = 9 in males. We have studied the evolution of this karyotype by hybridising chromosome-specific paints derived from flow-sorted chromosomes of the Chinese muntjac (M. reevesi, 2n = 46) to chromosomes of the black muntjac. The hybridisation pattern allowed us to infer chromosomal homologies between these two species. Tandem and centromeric fusions, reciprocal translocations, and insertions are involved in the reduction of the diploid number from 2n = 46 to 2n = 8, 9. The painting patterns further show complex chromosomal rearrangements in the male black muntjac which involve more than half the karyotype, including both sex chromosomes. Since early meiosis is reported to be normal without any visible inversion loops of the synaptonemal complex, the observed chromosomal rearrangements would lead to heterosynapsis and, therefore, leave a large fraction of the male black muntjac karyotype balanced between the two sexes.

Animals↗
PubMed1997

Conservation of human vs. feline genome organization revealed by reciprocal chromosome painting.

We employed fluorescence in situ hybridization (FISH) with probes established by flow sorting metaphase chromosomes of the domestic cat (Felis cattus, 2n = 38) to "paint" homologous segments on human chromosomes and, reciprocally, using human chromosome paints on feline metaphase preparations. The results revealed, by direct microscopic observation, widespread conservation of genome organization between the two mammalian orders and confirmed 90% of the homologous genes mapped to both species. Fourteen of 23 human chomosomes were hybridized with single cat probes, and 9 of 19 cat chromosomes were entirely labeled by a single human probe. All other chromosomes were labeled with only two or, at most, three probes of the respective species. Y-chromosome probes gave no signals. Approximately 30 syntenic segments were identified, and the number of translocations could be estimated to be on the order of one new translocation per 10 million years in the phylogenetic lines leading to human and cat. Using the principle of maximum parsimony, the primitive vs. derived human chromosome segments were identified by comparison to the feline, cattle, and pig genomes, a first step in reconstructing the evolutionary heritage of the mammalian radiations. The results suggest that reciprocal chromosome painting will help reconstruct the history of genomic changes by determining the polarity of chromosomal rearrangements and establishing the ancestral karyotype for each principle branching point in mammalian evolution.

Animals↗
PubMed1997

Reciprocal chromosome painting between human and prosimians (Eulemur macaco macaco and E. fulvus mayottensis).

We used fluorescence in situ hybridisation to delineate the homology between the human karyotype and those of two lemur species (Eulemur macaco macaco and E. fulvus mayottensis). Human and lemur chromosome-specific probes were established by bivariate fluorescence-activated flow sorting (FACS) and subsequent degenerate oligonucleotide-primed PCR (DOP-PCR). Reciprocal painting of human probes to lemur chromosomes and vice versa allowed a detailed analysis of the interchromosomal rearrangements that had occurred during the evolution of these species. The results indicate that the genomes of both species have undergone only a few translocations during more that 45 million years of lemur and human evolution. The synteny of homologs to human chromosomes 3, 9, 11, 13, 14, 17, 18, 20, 21, X, and Y was found to be conserved in the two lemur species. Taking non-primate mammals as the outgroup for primates, ancestral conditions for various primate chromosomes were identified and distinguished from derived forms. Lemur chromosome painting probes were also used for cross-species hybridization between the two lemur species. The results support an earlier assumption, made on the basis of chromosome banding, that the karyotypes of the two species have evolved exclusively by Robertsonian transformations. All probes derived from E. f. mayottensis chromosomes specific for homologs involved in rearrangements in E. m. macaco exclusively painted entire chromosome arms. The results further indicate that E. f. mayottensis most probably has a more ancestral karyotype than E. m. macaco. Probes derived from prosimians will be useful in comparing the karyotypes of other lower primates, which will improve our understanding of early primate genome evolution.

Animals↗
PubMed1997

Intradermal recombinant human nerve growth factor induces pressure allodynia and lowered heat-pain threshold in humans.

Nerve growth factor (NGF) plays a biologic role in the development and maintenance of sympathetic and small sensory neurons. Because it facilitates nerve fiber regeneration, lowers heat-pain threshold (hyperalgesia), and prevents or improves nerve dysfunction in experimental neuropathy, it is being considered as a putative treatment for certain human polyneuropathies. In 16 healthy subjects, we tested whether intradermal injection of minute doses of recombinant human NGF (1 or 3 micrograms) compared with saline induces hyperalgesia or alters cutaneous sensation (at the site of injection) as measured by symptom scores, clinical examination, or quantitative sensory testing with Computer Assisted Sensory Examination (CASE IV). Most subjects had, as their only symptom, localized tenderness of the NGF-injected site and only when the site was bumped or compressed. Slight discomfort developed in volar wrist structures (with flexion of fingers) or tenderness of deep structures to palpation over the bicipital groove or supraclavicular region. The Neuropathy Symptoms and Change questionnaire indicated that pressure allodynia was significantly localized to the NGF-injected side from 3 hours to 21 days after injections. Light stroking of the skin did not induce tactile allodynia. Compression of injected sites induced pressure allodynia that occurred more frequently and significantly on the NGF-injected side after 3 hours and was maintained for several weeks. No abnormality of vibratory or cooling detection threshold developed from NGF injection. By contrast, heat-pain threshold (HP 0.5, p = 0.003) and an intermediate level of heat-pain (HP 5.0, p < 0.001) were significantly lowered 1, 3, and 7 days (and in some cases at 3 hours and 14 and 21 days) after NGF injection. The time course of pressure allodynia and heat-pain hyperalgesia is too rapid to be explained by uptake of NGF by nociception terminals, retrograde transport, and upregulation of pain modulators. Local tissue mechanisms appear to be implicated. It remains to be tested whether recombinant human NGF prevents, stabilizes, or ameliorates small fiber human neuropathies.

Adolescent↗
PubMed1997

Longitudinal assessment of diabetic polyneuropathy using a composite score in the Rochester Diabetic Neuropathy Study cohort.

Because there are little satisfactory data on change in severity of diabetic polyneuropathy (DP) over time from study of population-based cohorts of diabetic patients in epidemiologic surveys of DP, it is difficult to predict outcome or morbidity or to identify risk factors; it is also difficult to estimate statistical power for use in controlled clinical trials. In this longitudinal study of almost 200 patients from the Rochester Diabetic Neuropathy Study (RDNS) cohort, we assess which symptoms, clinical examinations, tests, or combinations of examinations and tests (composite scores) are best used as minimal criteria for the diagnosis of DP and as a quantitative measure of severity of DP. An abnormality (> or = 97.5th percentile) of a composite score that included the Neuropathy Impairment Score of the lower limbs plus seven tests (NIS(LL)+7 tests), was a better minimal criteria for DP than clinical judgment alone or previously published minimal criteria. First, it provided a more comprehensive assessment of neuropathic impairment. Second, it avoided the overestimated frequency of DP when the minimal criteria for DP was any one or two abnormalities from multiple measurements. Minimal criteria using nerve conduction and reduced heart beat response to deep breathing identified approximately twice as many patients with DP than did clinical examination and vibration detection threshold using CASE IV. This difference could be used to subclassify state 1 DP. Although various individual measures of DP, for example, vibration detection threshold (as evaluated by CASE IV and the 4, 2, and 1 stepping algorithm [see text]), were good measures of worsening, the composite score NIS(LL)+7 tests (assessing neuropathic impairment) was much better at showing monotone worsening. Using this composite score, the average diabetic patient in the RDNS worsened by 0.34 points per year, whereas patients with diabetic polyneuropathy worsened by 0.85 points per year. On the assumption that a therapeutic agent may prevent worsening of DP but not cause improvement, controlled clinical trials of patients with DP would need to be conducted for a period of 3 years to achieve a meaningful change of 2 NIS points (the level of abnormality considered by a Peripheral Nerve Society consensus group to be clinically meaningful).

Adult↗
PubMed1997

Medial temporal atrophy on MRI in normal aging and very mild Alzheimer's disease.

Magnetic resonance imaging (MRI)-based volumetric measurements of medial temporal lobe (MTL) structures can discriminate between normal elderly control subjects and patients with Alzheimer's disease (AD) of moderate to advanced severity. In terms of clinical utility, however, a more important issue concerns the ability of the technique to differentiate between normal elderly control subjects and AD patients with the very mildest form of the disease. We performed MRI-based volumetric measurements of the hippocampus, parahippocampal gyrus, and amygdala in 126 cognitively normal elderly control subjects and 94 patients with probable AD. The diagnosis of AD was made according to NINDS/ADRDA criteria, and disease severity was categorized by Clinical Dementia Rating (CDR) scores. Patients with CDR 0.5 were classified as very mild, CDR 1 as mild, and CDR 2 as moderate disease severity. Volumes of each structure declined with increasing age in control subjects and did so in parallel for men and women. The volume of each measured MTL structure also declined with age in patients with AD. The volume of each MTL structure was significantly smaller in AD patients than control subjects (p < 0.001). Of the several MTL measures, the total hippocampal volumetric measurements were best at discriminating control subjects from AD patients. The mean hippocampal volumes for AD patients relative to control subjects by severity of disease were as follows: very mild AD (CDR 0.5) -1.75 SD below the control mean, mild AD (CDR 1) -1.99 SD, and moderate AD (CDR 2) -2.22 SD. Age- and gender-adjusted, normalized MRI-based hippocampal volumetric measurements provide a sensitive marker of the MTL neuroanatomic degeneration in AD early in the disease process.

Aging↗
PubMed1997

Approaches to improve epidemiological studies of diabetic neuropathy: insights from the Rochester Diabetic Neuropathy Study.

The quality of the epidemiological data on diabetic neuropathies remains poor for a variety of reasons. They include variability in 1) ascertainment of diabetes, 2) the clinical varieties of diabetic patients studied, 3) characterization of neurological dysfunction, 4) abnormal limits for neurological examinations and tests, 5) minimal criteria for neuropathy, 6) correct attribution of nondiabetic neurological disease, 7) correct attribution of type of neuropathy, 8) estimating neuropathy from use of multiple tests, and 9) estimating severity of polyneuropathy. We have tried to remedy these short-comings in the Rochester Diabetic Neuropathy Study (RDNS). It was not possible to adequately characterize and quantitate diabetic polyneuropathies using only one or two clinical or test abnormalities. To estimate severity of diabetic polyneuropathy, the results of the neurological examination and abnormalities of nerve conduction, quantitative sensory tests, and quantitative autonomic tests were combined into a composite score. One begins by scoring a standard test of neurological deficits (impairments) of the lower limbs (NIS[LL]) and adds to this transformed numbers for percentile abnormality of seven good functional tests. This NIS(LL)+7 tests score appears to provide a much more comprehensive and stable numeric score by which to diagnose and grade severity of diabetic polyneuropathy than does the use of individual clinical or test results. This test score should be useful as a measure of change in diabetic polyneuropathy for purposes of medical practice, epidemiology studies, and controlled clinical trials. The staging approach that we introduced previously continues to provide an important measure of overall severity of diabetic polyneuropathy, taking into account both symptoms and impairments.

Cross-Sectional Studies↗
PubMed1997

The classification of diabetes by clinical and C-peptide criteria. A prospective population-based study.

OBJECTIVE: To evaluate both the concordance in the classification of diabetes by clinical and C-peptide criteria and, prospectively, the consistency of the classification by C-peptide. RESEARCH DESIGN AND METHODS: Individuals with diabetes who were enlisted in the prospective epidemiological study of diabetic neuropathy (Rochester Diabetic Neuropathy Study [RDNS]) were classified clinically by National Diabetes Data Group (NDDG) criteria to IDDM and NIDDM at entry to the study. In addition, C-peptide response to 1 mg glucagon was measured at entry for the classification to IDDM (basal C-peptide, < 0.17 pmol/ml; increment above basal, < 0.07 pmol/ml) and NIDDM (all other responses) and for concordance with the clinical classification made. The consistency of the C-peptide response was assessed every 2 years for up to 8 years. RESULTS: Among 346 individuals with diabetes, 84 were classified as IDDM and 262 as NIDDM by clinical algorithm. COncordance with the C-peptide response occurred in 89% of the patients and remained consistent during 8 years of follow-up. Among the 37 patients with discordant clinical and C-peptide classification, those considered clinically to have NIDDM had a consistent IDDM C-peptide response during follow-up, and most of those considered to have IDDM clinically eventually showed an IDDM C-peptide response during follow-up. CONCLUSIONS: Clinical criteria for the classification of diabetes are highly correlated with the assessment of insulin secretory reserve. A small number of individuals considered to have NIDDM clinically or by C-peptide have or develop an IDDM peptide response.

Adolescent↗
PubMed1997

Dermal interstitial glucose as an indicator of ambient glycemia.

OBJECTIVE: Using a novel minimally invasive (< or = 1.4 mm) technique to sample minuscule (0.5 microliter) amounts of dermal interstitial fluid (ISF), we assessed the accuracy of its glucose concentrations in predicting concurrently measured venous plasma and capillary plasma glucose concentrations. RESEARCH DESIGN AND METHODS: A total of 67 adult (37 male and 30 female) volunteers (57 with and 10 without diabetes) with venous plasma glucose levels from 1.6 to 28.4 mmol/l underwent forearm ISF, antecubetal venous, and fingertip capillary sampling. RESULTS: Rank correlations were 0.974 for ISF 1 vs. 2, 0.954 for ISF vs. venous, 0.935 for ISF vs. capillary, and 0.987 for venous vs. capillary. Median absolute differences were 0.53 mmol/l for ISF 1 vs. 2, 1.33 mmol/l for ISF vs. venous, 1.06 mmol/l for ISF vs. capillary, and 0.56 mmol/l for capillary vs. venous. Equations expressing ISF glucose as a function of venous and capillary glucose and equations expressing capillary glucose as a function of venous glucose had slopes of 0.995, 0.936, and 1.021, respectively (none significantly different from unity), and intercepts of 1.03 mmol/l (P = 0.024), 0.94 mmol/l (P = 0.131), and 0.56 mmol/l (P = 0.041), respectively. Error grid analysis of ISF vs. venous glucose and of capillary vs. venous glucose showed that 97% of the measurements fell within grids A and B. CONCLUSIONS: Dermal ISF sampling is a bloodless minimally invasive technique that provides a medium for glucose measurement, the concentrations of which closely reflect ambient glycemia to a degree comparable with that of capillary glucose measurements.

Adult↗