Introducing computer literacy skills for physicians

Computers are integral to medical practice, education, and research. While medical students learn computer skills during their training, many practicing physicians do not have the same computer experience. To familiarize this group with the exciting developments in medical informatics, the Himmelfarb Health Sciences Library and Department of Computer Medicine at the George Washington University Medical Center organized a workshop "Introducing Your Office Computer!" for attending physicians. The workshop featured a short lecture/video presentation on computer applications in medicine followed by a "computer fair" of five computer applications. Eleven physicians attended the workshop. Feedback was very positive; many called later to request more detailed instructions on using the programs demonstrated. It was a valuable experience for the staff, and new bridges were built between departments and clients.

Resolution-enhanced Fourier transform infrared spectroscopy study of the environment of phosphate ion in the early deposits of a solid phase of calcium phosphate in bone and enamel and their evolution with age: 2. Investigations in the nu3PO4 domain

Resolution-enhanced Fourier Transform Infrared (FTIR) spectra of early mineral deposits in enamel and bone show bands at 1020, 1100, 1110, 1125, and 1145 cm-1 in the nu3PO4 domain which do not belong to well crystallized stoichiometric hydroxyapatite. Bands at 1020 and 1100 cm-1 have been shown to occur in nonstoichiometric apatites containing HPO4(2-) ions and the weak band at 1145 cm-1 has been assigned to HPO4(2-) ions. Though the bands at 1110 and 1125 cm-1 have not been found in any well crystallized apatite, they are present in newly precipitated apatite. These latter bands disappear progressively during maturation in biological as well as synthetic samples, and partial dissolution of synthetic apatites shows that they belong to species that exhibit an inhomogeneous distribution in the mineral, and that are the first to be solubilized. Comparison of the FTIR spectra of biological apatites with those of synthetic, nonapatitic-containing phosphate minerals shows that the presence of these bands does not arise from nonapatitic, well-defined phases; they are due to the local environment of phosphate ions which may possibly be loosely related or perhaps unrelated to the phosphate groups present in the well-crystallized nonapatitic calcium phosphates. Resolution-enhanced FTIR affords a very precise characterization of the mineral phases which may be very useful in characterizing pathological deposits of Ca-P mineral phases.

A resolution-enhanced Fourier transform infrared spectroscopic study of the environment of the CO3(2-) ion in the mineral phase of enamel during its formation and maturation

A resolution-enhanced Fourier Transform Infrared (FTIR) Spectroscopic study of the CO3(2-) ion in pig enamel of increasing age and maturity has demonstrated the existence of four different, main carbonate locations. The major CO3(2-) site arises as a result of the substitution of CO3(2-) ions in the positions occupied by PO4(3-) ions in the apatitic lattice. In addition, two minor locations have been identified in positions in which the CO3(2-) ions substitute for OH- ions. The fourth carbonate group appears to be in an unstable location. Its concentration has been found to decrease with aging and maturation, during which there is a progressive increase in the amount of mineral deposited in the enamel. The distribution of the carbonate ions in the different apatitic sites varies randomly during the formation of the mineral phase in enamel and during its maturation. Although these changes have been shown to be related to changes in the composition of the mineral phase, a comparison of the parameters assessing the degree of crystallinity of the mineral phase from upsilon 2CO3(2-) and upsilon 4PO4(3-) infrared absorption data reveals a significant discrepancy related to the nonhomogeneous partition of the CO3(2-) ion in the mineral phase. After maximum mineralization is reached, the composition of the mature mineral phase is decidedly different than that of the initial mineral deposited; the changes affect principally the concentrations of Ca2+, OH-, and HPO4(2-) ions, but not the CO3(2-) ions.

Fourier transform infrared spectroscopic study of the carbonate ions in bone mineral during aging

The environment of CO3(2-) ions in the bone mineral of chickens of different ages and in bone fractions of different density have been investigated by resolution-enhanced Fourier Transform Infrared (FTIR) Spectroscopy. Three carbonate bands appear in the upsilon 2 CO3 domain at 878, 871, and 866 cm-1, which may be assigned to three different locations of the ion in the mineral: in monovalent anionic sites of the apatitic structure (878 cm-1), in trivalent anionic sites (871 cm-1), and in unstable location (866 cm-1) probably in perturbed regions of the crystals. The distribution of the carbonate ions among these locations was estimated by comparing the intensities of the corresponding FTIR spectral bands. The intensity ratio of the 878 and 871 cm-1 bands remains remarkably constant in whole bone as well as in the fractions obtained by density centrifugation. On the contrary, the intensity ratio of the 866 cm-1 to the 871 cm-1 band was found to vary directly and decreased with the age of the animal. In bone of the same age, the relative content of the unstable carbonate ion was found to be highest in the most abundant density centrifugation fraction. A resolution factor of the CO3(2-) band (CO3 RF) was calculated from the FTIR spectra which was shown to be very sensitive to the degree of crystallinity of the mineral. The crystallinity was found to improve rapidly with the age of the animal. The CO3 RF in the bone samples obtained by density centrifugation from bone of the same animal was found to be essentially constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Unintentional injuries to students at school

Unintentional injuries at school have been identified as a significant public health problem. A major barrier to the development of injury prevention policy has been the absence of national data on the circumstances of injuries to students which occur at school. This study sought to determine the incidence, nature, and circumstances of injuries which resulted in death or hospitalization. Fatalities were identified from national mortality data for 1977-86 inclusive. Coroners' files were then examined to obtain details of the circumstances of injury. Hospitalization cases were identified from the national hospital discharge summary for 1986. Fifteen fatalities were identified. The circumstances of the deaths were diverse with the most frequent event being a fall (n = 4). A total of 1013 first admissions to hospital were identified, giving an overall incidence rate of 152/100,000 students/year. Injury rates declined with increasing age, and males had higher rates than females for all ages. Fractures of the upper and lower limbs and intracranial injury represented more than three-quarters of all injury. The two leading causes of injury, falls, and incidents involving striking against or being struck by a person or object, represented 89% of all incidents. The use of playground equipment and involvement in sporting activity were two of the more common aspects of many injury events. The results suggest that prevention policy should place emphasis on those in their first 2 years of schooling, falls from playground equipment, provision of protective equipment for sporting activities, sporting activities designed to minimize physical contact, establishment of standardized injury referral procedures, first-aid training, and a standardized injury reporting system.

Colorectal cancer in the north and south of Ireland 1950-1984

STUDY OBJECTIVE

Northern Ireland has the highest standardised mortality ratios for colon cancer in the United Kingdom and the Republic of Ireland has some of the highest mortality rates for cancer in the world. The aim of the study therefore was to investigate trends in colorectal cancer in the north and south of Ireland over the period 1950 to 1984.

DESIGN

The study was a cohort analysis of deaths from colorectal cancer for ages 35-74 years by five year age groups, divided by sex.

SETTING

This was a population study involving all cases reported to the Registrar General of Northern Ireland and the Eire Vital Statistics and Central Statistical Office during the study period.

MEASUREMENTS AND MAIN RESULTS

As in mainland Britain, rectal cancer mortality declined in the north and the south during the study period, but the fall began sooner for males than females. Colon cancer mortality fell in the late 1950s but subsequently rose to its previous high levels.

CONCLUSIONS

The observation that there were declines in mortality in the north and south of Ireland in the late 1950s does not support the hypothesis that altered diet due to war rationing in Great Britain and Northern Ireland underlay the fall in British colon cancer mortality after the war. The very high standardised mortality ratios for colon cancer in Northern Ireland highlight a continuing major public health problem in the region.

Recent experiences in the management of visual impairment in albinism

One hundred patients with albinism seen within two years in the Low Vision Clinic at Moorfields Eye Hospital are reviewed. They are predominantly young people within the definition of 'Partially-sighted' rather than blind. Clinical methods are described and the distribution of alternative types of appliance loaned surveyed. Emmetropia and low ametropia are rare in the group. Most patients are using telescopic lenses for distance vision, tending to select binocular devices. Over half are able to read print of newsprint size in a clinical situation without extra magnification, but often elect to use extra magnification for some tasks. The need for near vision aids increases with age.

Resolution-enhanced Fourier transform infrared spectroscopy study of the environment of phosphate ions in the early deposits of a solid phase of calcium-phosphate in bone and enamel, and their evolution with age. I: Investigations in the upsilon 4 PO4 domain

In order to investigate the possible existence in biological and poorly crystalline synthetic apatites of local atomic organizations different from that of apatite, resolution-enhanced, Fourier transform infrared spectroscopy studies were carried out on chicken bone, pig enamel, and poorly crystalline synthetic apatites containing carbonate and HPO4(2-) groups. The spectra obtained were compared to those of synthetic well crystallized apatites (stoichiometric hydroxyapatite, HPO4(2-)-containing apatite, type B carbonate apatite) and nonapatitic calcium phosphates which have been suggested as precursors of the apatitic phase [octacalcium phosphate (OCP), brushite, and beta tricalcium phosphate and whitlockite]. The spectra of bone and enamel, as well as poorly crystalline, synthetic apatite in the upsilon 4 PO4 domain, exhibit, in addition to the three apatitic bands, three absorption bands that were shown to be independent of the organic matrix. Two low-wave number bands at 520-530 and 540-550 cm-1 are assigned to HPO4(2-). Reference to known calcium phosphates shows that bands in this domain also exist in HPO4(2-)-containing apatite, brushite, and OCP. However, the lack of specific absorption bands prevents a clear identification of these HPO4(2-) environments. The third absorption band (610-615 cm-1) is not related to HPO4(2-) or OH- ions. It appears to be due to a labile PO4(3-) environment which could not be identified with any phosphate environment existing in our reference samples, and thus seems specific of poorly crystalline apatites. Correlation of the variations in band intensities show that 610-615 cm-1 band is related to an absorption band at 560 cm-1 superimposed on an apatite band. All the nonapatitic phosphate environments were shown to decrease during aging of enamel, bone, and synthetic apatites. Moreover, EDTA etching show that the labile PO4(3-) environment exhibited a heterogeneous distribution in the insoluble precipitate.

Thyroid and adrenal function tests in adult male ferrets

Effects of thyroid-stimulating hormone (TSH) and thyrotropin-releasing hormone (TRH) on plasma concentrations of thyroid hormones, and effects of ACTH and dexamethasone on plasma concentrations of cortisol, were studied in adult male ferrets. Thirteen ferrets were randomly assigned to test or control groups of eight and five animals, respectively. Combined (test + control groups) mean basal plasma thyroxine (T4) values were different between the TRH (1.81 +/- 0.41 micrograms/dl, mean +/- SD) and TSH (2.69 +/- 0.87 micrograms/dl) experiments, which were performed 2 months apart. Plasma T4 values significantly (P less than 0.05) increased as early as 2 hours (3.37 +/- 1.10 micrograms/dl) and remained high until 6 hours (3.45 +/- 0.86 micrograms/dl) after IV injection of 1 IU of TSH/ferret. In contrast, IV injection of 500 micrograms of TRH/ferret did not induce a significant increase until 6 hours (2.75 +/- 0.79) after injection, and induced side effects of hyperventilation, salivation, vomiting, and sedation. There was no significant increase in triiodothyronine (T3) values following TSH or TRH administration. Combined mean basal plasma cortisol values were not significantly different between ACTH stimulation (1.29 +/- 0.84 micrograms/dl) and dexamethasone suppression test (0.74 +/- 0.56 micrograms/dl) experiments. Intravenous injection of 0.5 IU of ACTH/ferret induced a significant increase in plasma cortisol concentrations by 30 minutes (5.26 +/- 1.21 micrograms/dl), which persisted until 60 minutes (5.17 +/- 1.99 micrograms/dl) after injection. Plasma cortisol values significantly decreased as early as 1 hour (0.41 +/- 0.13 micrograms/dl), and had further decreased by 5 hours (0.26 +/- 0.15 micrograms/dl) following IV injection of 0.2 mg of dexamethasone/ferret.(ABSTRACT TRUNCATED AT 250 WORDS)

The carbonate environment in bone mineral: a resolution-enhanced Fourier Transform Infrared Spectroscopy Study

The environment of carbonate ions in bones of different species (rat, rabbit, chicken, cow, human) was investigated by Fourier Transform Infrared Spectroscopy (FTIR) associated with a self-deconvolution technique. The carbonate bands in the v2 CO3(2-) domain show three components which were identified by using synthetic standards and different properties of the apatitic structure (ionic affinity for crystallographic locations, ionic exchange). The major component at 871 cm-1 is due to carbonate ions located in PO4(3-) sites (type B carbonate). A band at 878 cm-1 was exclusively assigned to carbonate ions substituting for OH-ions in the apatitic structure (type A carbonate). A band at 866 cm-1 not previously observed was shown to correspond to a labile carbonate environment. The intensity ratio of type A to type B carbonate appears remarkably constant in all bone samples. The 866 cm-1 carbonate band varies in its relative intensity in different species.

Natural occurrence of black-pigmented Bacteroides species in the gingival crevice of the squirrel monkey

The objective of this study was to determine whether the squirrel monkey (Saimiri scuireus) is indigenously colonized with black-pigmented bacteroides (BPB) resembling human Bacteroides gingivalis and Bacteroides intermedius (suspected periodontal pathogens) and to determine the usefulness of the squirrel monkey as an in vivo model for studying colonization by putative pathogens. We assayed the subgingival plaques of 138 monkeys of various ages and in four different colonies for the presence of anaerobic BPB microorganisms. We also tested half the animals for the presence of Actinobacillus actinomycetemcomitans. Clinical indices and levels of serum antibody to B. gingivalis were recorded. We detected BPB in 50% of the animals and A. actinomycetemcomitans in 69% of the animals. The presence of BPB was generally associated with increased age, increased gingival index, presence of calculus, and increased levels of serum antibody. These data indicate that the squirrel monkey may be a good model for studying the parameters of natural infection of the gingival crevice with suspected periodontopathogenic BPB microorganisms.

Tarsal coalitions. A new surgical procedure

Coalition is a congenital fusion of two or more tarsal bones. Symptoms, if present, usually begin in early adolescence. The typical symptom complexes are aching pain in the rearfoot exacerbated by activity, progression of the flatfoot deformity, decreased tarsal motion, and sometimes peroneal spasm. When patients are asymptomatic, no treatment is necessary. If symptoms begin, the individual should be treated conservatively. If that fails, surgical intervention should be undertaken. Calcaneonavicular coalitions respond well to excision with extensor digitorum brevis interposition. Talocalcaneal middle facet coalitions have responded well to resection with implant arthroplasty. When degenerative changes are present in the subtalar and midtarsal joints, triple arthrodesis is still the procedure of choice.

Surgical correction of transverse plane deformities at the lesser metatarsophalangeal joints

In this paper the authors discuss transverse plane deformities at the lesser metatarsophalangeal joints and propose a new surgical procedure for correcting these deformities. The results have been encouraging because the procedure does not interfere with function and there have been no recurrences.

Serologic and immunopathologic findings in temporal arteritis

In 104 patients undergoing biopsies for temporal arteritis, lymphocyte characterization identified both T4 helper/inducer and T8 cytotoxic/suppressor lymphocytes in approximately equal numbers. B lymphocytes were absent. Deposition of IgM and IgG was observed in three of 16 positive biopsy specimens. Antinuclear antibodies were present in ten of 16 biopsy-proven cases of temporal arteritis compared with 19 of 55 in the control group with negative biopsy specimens. Anti-smooth-muscle, anti-DNA, and antimitochondrial antibodies were not useful in distinguishing between the two groups.

Syntheses and adrenergic agonist properties of ring-fluorinated isoproterenols

2-Fluoro-, 5-fluoro-, and 6-fluoroisoproterenol were synthesized by reduction of the Schiff base formed between the corresponding ring-fluorinated 3,4-bis(benzyloxy)phenethanolamine and acetone, followed by reductive debenzylation in the presence of oxalic acid to yield crystalline neutral oxalates. The apparent beta-adrenergic potencies were determined in the isolated guinea pig atria. 2-Fluoro- and 5-fluoroisoproterenol were equipotent with (+/-)-isoproterenol, while 6-fluoroisoprotenol was virtually inactive. No alpha-adrenergic agonist activity (guinea pig aorta) was shown by any of the fluoroisoproterenols. Displacement of alpha- and beta-specific radioligands from isolated membrane preparations from rat brain by the fluoroisoproterenols were in agreement with the responses of the organ preparations. Thus, the apparent fluorine-induced specificity is due to specificity at the receptor binding site. The effects of fluorine substitution are discussed with regard to the apparent negative influence of the 6-fluoro substituent on the beta-agonist properties of isoproterenol, the lack of any increase in potency due to the 2-fluoro substituent, and the possibility of fluorine-induced changes in the electron density of the aromatic ring as a possible rational for the fluorine-induced specificity of both the fluoroisoproterenols and the fluoronoirepinephrines.

Toxicological procedures for assessing the carcinogenic potential of agricultural chemicals

Pesticides and other agricultural chemicals are now widely used throughout the world as a means of improving crop yields in order to meet the increasing demands being placed upon the global food supply. In Canada, the use of such chemicals is controlled through government regulations established jointly by the Department of Agriculture and the Department of National Health & Welfare. Such regulations require a detailed evaluation of the toxicological characteristics of the chemical prior to its being cleared for use. In this paper, procedures for assessing the carcinogenic potential of agricultural and other chemicals are discussed. Consideration is given to both the classical long-term in vivo carcinogen bioassay in rodent or other species and the more recently developed short-term in vitro tests based on genetic alterations in bacterial and other test systems.

Reversal by testosterone of atrophy of accessory genital glands of castrated male sheep. A histologic and morphometric study

The histologic features of male accessory genital glands of entire sheep (group I), castrated sheep (group II), castrated sheep treated with 40 daily intramuscular injections of 50 milligrams testosterone propionate (group III), and castrated sheep treated with 600 milligrams testosterone propionate 72 hours before death (group IV) were compared. Sheep were castrated at 3 months old and all sheep were killed when 15 months old. Volume fractions of glandular tissue, intralobular fibromuscular tissue and perilobular fibromuscular tissue of the seminal vesicles and Cowper's glands fluctuated significantly (P less than 0.05) during postcastration atrophy and after repeated testosterone treatment. Atrophy in sheep in group II was least in the prostate but greatest in Cowper's glands, seminal vesicles and ampullae of vasa deferentia. Seminal vesicle plexi, whose cytons had a statistically significant (P less than 0.05) degree of shrinkage, also were atrophied. After treatment with testosterone the postcastration atrophy of plexal neurons was almost reversed in sheep in group III. There also was hypertrophy of epithelial cells but the testosterone treatment failed to reduce to normal the fibromuscular volume fraction of the accessory genital glands. Testosterone propionate treatment of sheep in group IV failed to elicit appreciable morphologic changes. These results are compared with our previous findings on the content and uptake of zinc by the accessory genital glands. It is suggested that accumulation of zinc in the accessory genital glands of sheep is not necessarily closely linked to normal histologic appearance.

Reducing auditory feedback and the acquisition of motor response timing

Three groups of subjects (n=10) attempted to move a lever 50 cm along a track in 1.50 sec under one of three auditory feedback conditions: Fully augmented increasing auditory feedback (FAF) in which a constant level of velocity-related auditory feedback was provided for all 25 learning trials, reducing auditory feedback (FAF) in which the level of feedback was progressively reduced over the learning trials, and no auditory feedback (NAF). All subjects performed 10 trials with no auditory feedback after a 10-min rest interval. The hypothesis that acquisition of the criterion task would be facilitated under RAF compared to FAF derived partial support. It was concluded that there is sufficient evidence to justify further investigation of reducing auditory feedback as a technique of motor skill acquisition.

Hexachlorobenzene residues and effects on esterase activities in pre-weanling rats after a reciprocal transfer between HCB-treated and control dams

Female Wistar rats were divided into two groups. One group was fed ad libitum powdered rat chow containing 80 ppm hexachlorobenzene (HCB) and the other was fed HCB-free diet 2 weeks before mating until the termination of the experiment. Immediately after parturition, the pups were randomly culled to 10 per litter and 5 pups were reciprocally transferred between HCB and control dams. All pups within same paired litters were sacrificed on the 16th to 17th day and on the 20th to 23rd day after birth. Liver esterase activity toward indophenyl, thiophenyl, and p-nitrophenyl acetates was determined. The liver to body weight ratio, liver esterase activity and HCB residues were significantly higher in pups nursed by HCB-fed dams than in those nursed by control dams. The HCB residue in the liver, kidney, spleen, heart and brain was analyzed by gas-liquid chromatography. At about the weaning time, the HCB residue levels in pups transferred after parturition from HCB fed to control dams were similar to those in pups which remained with the control dams. The results demonstrated that HCB in tissues at about weaning time was obtained largely through milk. In addition, transmission of HCB through milk had greater effects on esterase activities in suckling pups than placental transmission. The pups born to HCB-treated dams and nursed by the control dams were similar to the pups born and nursed by the same control dams.

Cardioplegia without fibrillation or defibrillation in cardiac surgery

A group of 176 patients undergoing cardiac surgery utilizing a technique of rapid core hypothermic cardioplegia with a hyperosmotic solution is presented. A cold, 2 to 4 degrees C hyperosmotic (396 mOsm) perfusate, injected under pressure, induced cardiac arrest without fibrillation within 2 to 4 seconds in every instance. At the end of each procedure, flushing of the cold solution out of the coronary system re-establishes spontaneous normal sinus cardiac rhythm in 96% (119 of 124) of coronary surgical procedures, 69% (11 of 16) of aortic valve replacements, 62% (10 of 16) of mitral valve replacements, 55% (five of nine) of aortic valve replacements combined with multiple coronary grafting, 57% (four of seven) of mitral valve replacement combined with multiple coronary grafting, and in 50% (two of four) of double valve replacements. Combined core and topical hypothermia with ice slush used in valve replacements and combined valve with coronary operations allowed periods of total ischemia up to 134 minutes without signs of detectable myocardial damage.