Effect of Mutans streptococcal colonization on plaque formation and regrowth in young children--a brief commnunication.

OBJECTIVES: Visible plaque on the maxillary anterior teeth of young children has been identified as a risk indicator for early childhood caries. The present study examined whether this plaque is related to the colonization of children's teeth with Mutans streptococci (MS) or toothbrushing frequency. METHODS: Thirty-nine children, aged 12 to 36 months, had plaque scores, and plaque samples were taken from the labial surfaces of the maxillary incisors at baseline and repeated 3 days after suspended oral hygiene (plaque regrowth). RESULTS: A positive correlation was found between the baseline percent MS and regrowth plaque score and between baseline and regrowth plaque scores. Plaque scores of those that brushed zero to one time a day were not different from those who brushed two or more times a day. CONCLUSIONS: This study suggests that the presence of plaque on the anterior teeth of young children is consistent and related to MS colonization.     

Use of split-liver allografts does not impair pediatric recipient growth.

The use of split-liver (SL) allografts continues to be an excellent option for many pediatric recipients. Patient and graft survival with this graft type are comparable to patient and graft survival with whole organ grafts. Quality-of-life issues, specifically growth, for SL recipients have not been compared to those of recipients of more conventional whole-organ recipients. Pediatric recipients of SL and whole allografts at 2 institutions were identified. Height, z score, and delta z score were calculated for all recipients for each year after transplant. Between 1995 and 2004, 201 pediatric liver transplants were analyzed. Data were collected on 39 split-graft recipients and 36 whole-size recipients. Only subjects 3 years or younger were included in the study. Growth retardation was present in all recipients at transplant. Height z score post split and whole-size transplant were not statistically different at 1- (P = 0.65), 2- (P = 0.13), and 3-year (P = 0.32) anniversaries, respectively. Catch-up growth was present only in recipients of split grafts. In conclusion, the use of split grafts as opposed to whole-size grafts revealed no significant differences in terms of linear growth. Our report indicates that split-liver transplantation does not impair recipient growth.     

Pyruvate-modified perfadex improves lung function after long-term hypothermic storage.

BACKGROUND: Lungs harvested for transplantation are stored while inflated with oxygen, which can serve to support oxidative metabolism. However, strategies aimed at increasing graft metabolism during storage have received little attention. In this study, we added pyruvate to the preservation solution Perfadex and measured the effects on oxidative metabolism and reperfusion lung function. METHODS: Rat lungs were stored for 6 and 24 hours in low-potassium dextran solution at 10 degrees C containing either 5 mmol/liter uniformly carbon-13 (U-(13)C) labeled glucose (Perfadex), 32 mmol/liter 3-(13)C pyruvate (pyruvate), or both (combined). Oxidation of exogenous substrates was measured as the incorporation of (13)C into tricarboxylic acid cycle intermediates by magnetic resonance spectroscopy. Additional groups of lungs with each substrate modification were preserved for 6 or 24 hours and then reperfused. RESULTS: Enrichment of tricarboxylic acid cycle intermediates was low in the Perfadex group (9% at 6 hours and 32% at 24 hours of storage, respectively). In contrast, enrichment was significantly increased in both the pyruvate group (50% and 59%, respectively) and combined group (39% and 54%, respectively) compared with the Perfadex group (p<0.01). Graft function was excellent after 6-hour storage in all groups. All lungs stored for 24 hours exhibited inferior lung function, but oxygenation, pulmonary artery pressures, and airway pressures in the combined group were significantly improved compared with the Perfadex group (p<0.05). CONCLUSIONS: Preservation solution substrate composition influences graft metabolism during storage. The addition of pyruvate to Perfadex increases metabolism during storage and improves reperfusion lung function.     

Scale-up of Adhesive Transdermal Drug Delivery Systems

Pharmaceutical Research -     

Efficacy of a patient-training videotape on motor fluctuations for on-off diaries in parkinson's disease

Patient on-off diaries are used in clinical trials, but a method to assure agreement between patient and examiner has never been developed. We tested whether a patient-teaching tape increased the rate of agreement between patient diary ratings and simultaneous neurologic assessment by a trained professional. A total of 32 consecutive patients who had Parkinson's disease with motor fluctuations independently completed a 4-h on-off diary (nine ratings) at the same time as an examiner. Those with <80% agreement with the examiner (n = 20) were randomized to view either a training tape that showed motor fluctuations (experimental group) or another videotape of general patient educational material (control group). All patients then underwent the same 4-h assessment of motor fluctuations. To test for long-term retention, they returned 1 month later and, without reviewing the videotape, underwent a final 4-h correlation assessment. After the training tape, the experimental group showed significant improvement, whereas the control group showed no improvement. Furthermore, another month later, the improvement in the experimental group was retained. Based on these findings, we suggest that future clinical trials assessing motor fluctuations incorporate this tape into their basic methodology.     

Association between pancreatic cystadenocarcinoma, malignant liver cysts, and polycystic disease of the kidney

Polycystic kidney disease is an autosomal dominant disease that may be associated with cystic disease of the liver. In women, the cysts may develop early and be more troublesome than in men. Cystadenocarcinoma of the pancreas is uncommon, comprising 1% of primary pancreatic malignancies. This case report is the first to describe a familial association between polycystic kidney disease and cystadenocarcinoma of the pancreas and liver in the English medical literature. A patient with autosomal dominant polycystic kidney disease (ADPKD) and multiple hepatic cysts developed cystadenocarcinoma of the pancreas with multiple malignant liver cysts. The patient's mother, sister, and niece had ADPKD, and the patient's sister also died of pancreatic cystadenocarcinoma. We believe that the development of these two disease entities in which the primary pathology is cyst formation has a genetic association. (Gastroenterology 1997 Jun;112(6):2104-7)     

Preliminary investigation of respiratory self-gating for free-breathing segmented cine MRI.

Segmented cine MRI generally requires breath-holding, which can be problematic for many patients. Navigator echo techniques, particularly successful for free-breathing coronary MRA, are incompatible with the acquisition strategies and SSFP pulse sequences commonly used for cine MRI. The purpose of this work is to introduce a new self-gating technique deriving respiratory gating information directly from the raw imaging data acquired for segmented cine MRI. The respiratory self-gating technique uses interleaved radial k-space sampling to provide low-resolution images in real time during the free-breathing acquisition that are compared to target expiration images. Only the raw data-producing images with high correlation to the target images are included in the final high-resolution reconstruction. The self-gating technique produced cine series with no significant differences in quantitative image sharpness to series produced using comparable breath-held techniques. Because of the difficulties associated with breath-holding, the respiratory self-gating technique represents an important practical advance for cardiac MRI. , Inc.     

Repair of DNA lesion O 6-methylguanine in hepatocellular carcinogenesis

Evidence from both experimental carcinogenesis and studies in human cirrhotic liver suggest that defective repair of the promutagenic DNA base lesion, O ⁶-methylguanine, is a factor in the multistep process of hepatocellular carcinogenesis. Ubiquitous environmental alkylating agents such as N-nitroso compounds can produce O ⁶-methylguanine in cellular DNA. Unrepaired, O ⁶-methylguanine can lead to the formation of G ? A transition mutations, a known mechanism of human oncogene activation and tumour suppressor gene inactivation. Combined treatment of rodents with an agent producing O ⁶-methylguanine in DNA, and an agent promoting cell proliferation, leads to development of hepatic nodules and hepatocellular carcinoma (HCC), cell division, hence DNA replication, being required for the propagation of tumorigenic mutation(s) in hepatocyte DNA. The paramount importance of O ⁶-methylguanine in hepatocellular carcinogenesis is indicated by the observation that transgenic mice engineered to have increased hepatic levels of repair enzyme O ⁶-methylguanine-DNA methyltransferase (MGMT) are significantly less prone to hepatocellular carcinogenesis following alkylating agent treatment. Cirrhosis is a universal risk factor for development of human HCC, and a condition that is characterized by increased hepatocyte proliferation as a result of tissue regeneration. Levels of the human repairing enzyme for O ⁶-methylguanine were found to be significantly lower in cirrhotic liver than in normal tissue. In accord with findings from animal models, this suggested a mechanism in which persistence of O ⁶-methylguanine due to defective DNA repair by MGMT, together with increased hepatocyte proliferation, might lead to specific gene mutation(s) and hepatocellular carcinogenesis. Screening for the presence and persistence of O ⁶-methylguanine in human DNA presently involves formidable technical difficulty. Indications are that such limitations might be overcome by the use of an ultrasensitive method such as immuno-polymerase chain reaction (PCR). This approach should allow parallel measurement of DNA adduct and repair enzyme in routine liver biopsy samples. It might also enable investigation of O ⁶-methylguanine in human genes specifically associated with hepatocellular carcinogenesis. Given the wide variation in human MGMT levels observed between individuals, tissues, and cells, this technology should be adapted to permit the ultrasensitive localisation and measurement of adducts and repairing enzyme in liver biopsy tissue sections. Ability to ultrasensitively measure O ⁶-methylguanine, and its repair enzyme, should prove valuable in the risk assessment of cirrhotic patients for developing hepatocellular carcinoma. Received for publication on July 6, 1998; accepted on Aug. 12, 1998