Biomedical subjects
Publications and source records attributed to J R Hall.
Recurrent parotid sialadenitis due to isolated parotid duct stenosis is an uncommon condition and poses a difficult management problem. Conventional surgical practice carries with it a potentially high morbidity for what is a benign condition. We present three cases where parotid duct stenosis has been treated by balloon dilatation and propose that this is a safe, quick and repeatable method for dealing with this problem.
The routine use of arteriography for evaluating penetrating extremity injuries is undergoing reevaluation in the adult literature. Its role in children is less clear. Eighty-seven children treated for penetrating extremity trauma over a 5-year period were studied retrospectively to define the usefulness of arteriography. The ages ranged from 2 to 16 years. Twenty-four arteriograms were performed. Twelve were for patients who exhibited physical signs of vascular injury (diminished pulse, distal ischemia, expanding hematoma, or bruits/thrills over the wound). The other 12 were performed on asymptomatic children with wounds in proximity to major vessels. Two other patients with ongoing hemorrhage were taken directly to the operating room. Of the 12 arteriograms performed for abnormal physical signs, eight (67%) showed vascular injuries. None of the studies performed for proximity alone had abnormal results (P < .01). Ten of 10 patients with vascular injuries had abnormal physical findings, whereas only four of 77 patients without vascular injuries had abnormal findings (sensitivity 100%, specificity 95%). Eighty-five percent of patients have had follow-up in the pediatric surgery clinic, and no missed injuries or complications have been discovered. Timely diagnosis and repair is the cornerstone for successful management of vascular injuries. While the arteriogram is an important adjunct in patients who have abnormal physical findings, proximity to major vessels alone fails to identify patients at risk for significant injuries. Angiography may not be warranted in patients whose physical examination results are normal. Noninvasive modalities such as B-mode ultrasound and Doppler may have future application in the evaluation of these cases.
A randomized prospective trial was undertaken on 196 consecutive patients referred for double-contrast barium enema examination to assess the relative efficacy of three colon cleansing regimes: Citramag (2 sachets), Picolax and Picolax with a preliminary cleansing enema. Each of the regimes was preceded by a 5 day low residue diet. The radiographs from the examinations were assessed on a double-blind basis. The quality of bowel preparation was significantly poorer (P < 0.001) in the group receiving the preliminary cleansing enema, notably with respect to mucosal coating, compared with the other two groups. The quality of the preparation was slightly better in the group receiving Picolax alone than in the Citramag group (P < 0.01), the difference being most apparent in the proximal colon. The laxatives were equally well tolerated. The study has formed the basis of a departmental audit. As a result, the bowel preparation has been standardized to a 5 day period of dietary restriction followed by 2 Picolax sachets. This measure has improved efficiency within the department with no sacrifice in quality.
This study was conducted to determine the extent of blood contamination of anesthesia equipment and monitoring equipment in clinical use in operating rooms. The study employed a catalytic-test method, which is used in forensic medicine, to detect blood contamination of anesthesia equipment and monitoring equipment. Nineteen definable surfaces were sampled in 22 operating rooms. Thirty-three percent of surfaces were contaminated with blood. Contaminated equipment included surfaces that are in continuous contact with patients, e.g., blood pressure cuffs and pulse oximeter probes. Visual inspection was not a reliable means of detecting blood contamination. Whether this blood contamination represents an infection risk was not determined. Nevertheless, improved cleaning and disinfection procedures are probably needed. Equipment design needs to focus on reducing the potential for blood contamination and enhancing capability for cleaning and disinfection.
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OBJECTIVE: Trauma is the leading cause of death in children older than 1 year in the United States. We performed an analysis of the causes of death due to trauma in children in a large urban community to suggest means of prevention in such communities. We also examined data obtained before and after the designation of pediatric trauma centers to determine whether this has made a difference. DATA SOURCES: Records of the Medical Examiner, Cook County, Illinois, from 1983 through 1988. STUDY SELECTION: The admitting log was reviewed for all children before their 16th birthday. During the 6-year study period, 3121 autopsies were performed on children, 36.1% of whom died due to traumatic injuries. We reviewed the records of those children who died secondary to these injuries. DATA EXTRACTION: Record review on pediatric trauma deaths as to cause of death, time of death, age, sex, and any other pertinent information. RESULTS: Of all trauma deaths, fire was the most common cause of death, followed by motor vehicle-related injuries, homicides, drownings, and falls. These findings differ from national statistics. Improvement in outcome was seen following the designation of general trauma centers, with further improvement seen following the designation of specific pediatric trauma centers. CONCLUSIONS: Identification of causes of pediatric trauma death enables us to suggest methods of prevention. The centralized care of seriously injured children through the establishment of trauma centers and, specifically, pediatric trauma centers might help to prevent these deaths. Further study of pediatric trauma deaths, including hospital and ambulance records, is needed to improve medical care.
Medical educators and credentialing organizations recently have called attention to the long hours that some house staff are required to spend in the hospital during training. To determine the average duration of in-hospital work hours of anesthesiology residents, 148 residents at seven, university-affiliated training programs kept daily logs of their activities for one week. Residents in clinical anesthesia years 1, 2, and 3 spent an average of 66, 65, and 64 hours per week, respectively, in the hospital with a range of 43 to 104 hours per week. Although there was not a difference in in-hospital work time among years of training, there was a statistical difference between two of the seven programs studied. The largest portion of the in-hospital time was devoted to patient care activities in the operating room. Residents had time for educational activities, conferences, and reading while in the hospital. The overall work hours of the residents in the anesthesiology training programs included in this survey appeared to be within current guidelines.
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To compare catchments of possible acidified waters in Britain an extensive database was compiled for nearly 600 catchments of lakes and streams for which chemical data were available. Information on the database included map-derived data, pollutant deposition estimates and hydrological characteristics. To stratify the catchment database a randomly selected subset of 328 catchments was used to derive eight classes of catchments using the classification program TWINSPAN. Several classifications were generated by this method using an increasing number of catchment parameters. TWINSPAN classes were defined on the basis of some catchment parameters (indicators) but were shown to be associated with other variables. A general linear model (GLM) analysis of the available chemical data was used to test the different classifications. A TWINSPAN classification which excluded soil and geology characteristics gave the best GLM model because soil and geology types were poorly correlated with other catchment parameters. However, because of the recognized importance of soils and geology in acidification processes, these parameters were introduced into the GLM model as separate GLM classes. The resulting three-class model (TWINSPAN class, soil type, geology type) proved superior to both the one-class model and to two-class models which included either soil or geology. It was demonstrated that the TWINSPAN classes were associated with particular geographical areas and particular monitoring programmes. The TWINSPAN classification was used to evaluate a set of catchments selected as long-term monitoring sites for Britain. In general, the set covered a wide range of catchment types as defined by the classification. It was possible to identify minor shortfalls in classes of catchment selected and suggest possible additions to the sampling programme. Whilst the classification procedure has been applied to possible acidified waters, the method is of general relevance to all catchments and waters of more diverse nature.
Biliary obstruction was caused by viscid mucus in two patients with congenital bile duct abnormalities. In one patient this produced a progressive dilatation and obstruction of the common bile duct which eventually led to the patient's death; in the other there was a progressive segmental dilatation of the biliary tree which was surgically resected. We wish to emphasize that bile duct mucus has a characteristic appearance on cholangiography but is difficult to recognize on ultrasound and CT scans.
Type 1 or insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease of the insulin-producing pancreatic beta-cells which is determined by both genetic and environmental factors. The major histocompatibility complex and the insulin gene region (INS) on human chromosomes 6p and 11p, respectively, contain susceptibility genes. Using a mostly French data set, evidence for linkage of INS to IDDM was recently obtained but only in male meioses (suggesting involvement of maternal imprinting) and only in HLA-DR4-positive diabetics. In contrast, we find evidence for linkage in both male and female meioses and that the effect of the susceptibility gene(s) in the INS region is not dependent on the presence of HLA-DR4.
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Two genes, Idd-3 and Idd-4, that influence the onset of autoimmune type 1 diabetes in the nonobese diabetic mouse have been located on chromosomes 3 and 11, outside the chromosome 17 major histocompatibility complex. A genetic map of the mouse genome, analysed using the polymerase chain reaction, has been assembled specifically for the study. On the basis of comparative maps of the mouse and human genomes, the homologue of Idd-3 may reside on human chromosomes 1 or 4 and Idd-4 on chromosome 17.
A general conceptual framework has been developed as an aid to discussions of alternative approaches to fire risk analysis. The purpose is to show how each alternative seeks to address a few common concerns. Basic concepts and key elements--notably scenario structures, appropriate probability functions, and security and outcome measures--are defined and discussed, as are types of modeling approaches. A number of diverse examples are then presented using the framework to illustrate its value in making comparisons.
Over a 4-year period, 1,237 children under 16 years of age were managed at our level-I pediatric trauma center, of which 24 (1.9%) had zone-II penetrating neck injuries. Six of these 24 children (25%) were explored surgically with positive findings in four and negative findings in two neck explorations; five children (21%) underwent radiologic or endoscopic studies and were observed; 13 (54%) were observed only and did not require studies or exploration. Nonoperative observation of penetrating zone-II neck injuries is safe and the procedure of choice if active observation can be performed and the facilities for immediate operative intervention are available.
A prospective randomized study was undertaken to compare the use of the combination of gentamicin and clindamycin with single agent, cefoxitin, in the treatment of perforated appendicitis in the pediatric patient. In a 3-year period from 1986 to 1989, 56 patients with perforated appendicitis were randomized. Twenty-nine patients received cefoxitin, and 27 patients received gentamicin and clindamycin. Antibiotics were started before operation and continued for a minimum of 6 days after operation. Skin and subcutaneous tissues were left open at surgery and closed secondarily after day 3, if they appeared to be clean. Wounds were considered infected if they developed increased purulence with positive wound cultures. Age range was similar in both groups, with a mean of 9 years (range, 1 to 17 years); 28 were boys and 28 were girls. No changes in antibiotics were required for reasons of susceptibility. No adverse drug reactions occurred in either group. The most common organisms were Escherichia coli in 35 cases (62%) and Bacteroides species in 26 cases (46%). No difference was noted in infection complications in the two groups nor in length of hospital stay. Therefore, no difference is evident in the use of cefoxitin versus gentamicin and clindamycin in the treatment of perforated appendicitis in terms of disease or drug-related complications.
Natural sequence variation of the thrombospondin related anonymous protein (TRAP) gene of Plasmodium falciparum has been investigated by DNA analysis following the polymerase chain reaction amplification, and this shows the gene to be highly polymorphic. The region containing the sequence motif Trp-Ser-Pro-Cys-Ser-Val-Thr-Cys-Gly (WSPCSVTCG), common to TRAP, the circumsporozoite protein, properdin, and thrombospondin, was invariant. Elsewhere in the molecule, over 50 amino acid substitutions are described including the insertion of an in-frame, small-variable tandemly repeating motif between amino acid residues 352 and 353. Only one silent mutation was observed. Most nucleotide changes that occur in the first two codon positions result in conservative amino acid changes. Restriction fragment length polymorphism (RFLP) analysis was used to examine inheritance of TRAP in a cross between the HB3 and 3D7 clones of P. falciparum. Out of nine progeny examined, four possessed the HB3 gene and five the 3D7 gene. The TRAP gene hybridized to chromosome 13. Previous work has shown that a subtelomeric region of chromosome 13 from the 3D7 parent (marked by the HRP-III gene) was favoured strongly in this cross. The TRAP gene, however, is over 1 Mb away from this subtelomeric region and exhibits no such linkage because of chromosome crossovers. Five geographically separate isolates shared the same TRAP sequence as well as the same variant of the Th2R/Th3R region from the circumsporozoite protein. The correlation between independent markers in these isolates suggests that they have a common provenance.