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Biomedical subjects

T R Smith

Publications and source records attributed to T R Smith.

At least 19 recordsLinked to original sources
PubMed1992

Actinomycosis of the distal colon and rectum.

Actinomycosis of the colon has rarely been reported; two such cases are presented. A predisposing factor appears to be the presence of a pre-existing intrauterine device (IUD). This history was present in one case in which there was perisigmoid abscess, local extension, and fistulous tract or the anterior abdominal wall. A second patient had anorectal involvement which resembled Crohn's disease, and was found to be HIV positive. There was mucosal irregularity, wall thickening, reactive adenopathy, perirectal fascial thickening, and a sinus tract, which responded well to penicillin. It is unclear if there is an increased incidence of clinical actinomycosis in the HIV positive population, as it has not to our knowledge been previously reported.

Actinomycosis↗
PubMed1992

Guaiac testing in the diagnosis of rectal trauma: what is its value?

Rectal examination with guaiac testing is a standard part of the emergency department evaluation of acutely traumatized patients. Its major role is in the recognition of occult bowel injury. We questioned its efficacy in detecting occult rectal injury in patients with penetrating trauma. We reviewed the charts of 19 patients with suspected rectal injury. Ten injuries were to the abdomen, nine to the buttock, and three to the thigh. Guaiac testing was 69% (11/16) sensitive and 33% (1/3) specific. Rigid sigmoidoscopy was 100% (12/12) sensitive and 67% (2/3) specific. Sensitivity was 100% (8/8) when the two were combined. Our findings suggest that guaiac testing is not accurate enough to rule out the presence of occult rectal injury. The result of guaiac testing must not influence the decision to further evaluate patients with high-risk injuries.

Adult↗
PubMed1992

Plasticity of the human otolith-ocular reflex.

The eye movement response to earth vertical axis rotation in the dark, a semicircular canal stimulus, can be altered by prior exposure to combined visual-vestibular stimuli. Such plasticity of the vestibulo-ocular reflex has not been described for earth horizontal axis rotation, a dynamic otolith stimulus. Twenty normal human subjects underwent one of two types of adaptation paradigms designed either to attenuate or enhance the gain of the semicircular canal-ocular reflex prior to undergoing otolith-ocular reflex testing with horizontal axis rotation. The adaptation paradigm paired a 0.2 Hz sinusoidal rotation about a vertical axis with a 0.2 Hz optokinetic stripe pattern that was deliberately mismatched in peak velocity. Pre- and post-adaptation horizontal axis rotations were at 60 degrees/s in the dark and produced a modulation in the slow component velocity of nystagmus having a frequency of 0.17 Hz due to putative stimulation of the otolith organs. Results showed that the magnitude of this modulation component response was altered in a manner similar to the alteration in semicircular canal-ocular responses. These results suggest that physiologic alteration of the vestibulo-ocular reflex using deliberately mismatched visual and semicircular canal stimuli induces changes in both canal-ocular and otolith-ocular responses. We postulate, therefore, that central nervous system pathways responsible for controlling the gains of canal-ocular and otolith-ocular reflexes are shared.

Adaptation, Physiological↗
PubMed1991

Evidence for genetic mediation of alcoholism in women.

This review focuses on the etiology of alcoholism in women, examining the role of genetic vulnerability. The review is organized with respect to (1) the genetic epidemiology of alcoholism in women; (2) genetic models that take gender into account; (3) further discussion of the genetic heterogeneity of alcoholism as it relates to gender; and (4) presentation of data obtained from the Pittsburgh family study. This review concludes that, although much evidence remains to be gathered concerning the question of whether or not alcoholism is genetically mediated to the same degree in women as it is in men, there is no reason to rule out this possibility at the present time.

Alcohol Drinking↗
PubMed1991

Risk markers for alcoholism in high-density families.

This review summarizes the efforts of our research program to identify markers for alcoholism risk, which broadly fall within the domain of temperament and those which may be described as attentional or information-processing capacities. Analyses of three-generation pedigrees that include minor children at higher risk of becoming alcoholic indicate that event-related potential characteristics differ between high- and low-risk children. Newer results concerning cardiac responsivity both in minor children and adult high-risk individuals are presented. These results suggest a relationship between personality or temperament on the one hand, and cardiac responsivity on the other. Additional neurobehavioral markers are addressed including static ataxia. Recent segregation analyses and linkage to particular DNA segments are also included.

Adolescent↗
PubMed1990

Comparison of computed tomography and contrast enema evaluation of diverticulitis.

A total of 31 patients with diverticulitis were analyzed who had both computed tomography and contrast enema. There was almost equal sensitivity to abnormality of approximately 90 percent. Contrast enema produced a specific diagnosis of diverticulitis in 61 percent, using stringent positive criteria, and an additional 29 percent with suggestive findings. Comparative computed tomography specific diagnoses in those 31 cases was made in 65 percent, and suggestive in 23 percent. Computed tomography was particularly useful diagnostically in cases of retrograde obstruction on contrast enema. The authors conclude that contrast enema should be the primary mode of approach, while computed tomography can be a valuable follow-up when the diagnosis is still in doubt, or if it is possible that patient management might be altered by additional information.

Barium Sulfate↗
PubMed1990

Nonmucosal predominantly serosal eosinophilic enteritis. A case report.

A unique case of eosinophilic enteritis with predominant serosal involvement and mucosal sparing, ascites and abdominal adenopathy is reported with computed tomography (CT) and barium study correlation. The clinical presentation may mimic lymphoma or granulomatous disease, (e.g. tuberculosis) but peripheral eosinophilia is a strong differentiating point.

Adult↗
PubMed1990

Regulation of bovine adipose tissue metabolism during lactation. 6. Cellularity and hormone-sensitive lipase activity as affected by genetic merit and energy intake.

Subcutaneous adipose tissue cell size and density and hormone-sensitive lipase activity were determined during late pregnancy and first lactation in Holstein heifers. Animals were daughters of bulls with either +791 (high line) or +390 (low line) kg Predicted Difference (1974 base) for milk. Each line consumed either a 71%: 29% (high energy) or a 36%:63% (low energy) barley concentrate and alfalfa hay diet from 0 to 140 d lactation. Heifers fed the low energy ration ate 33% less NE1 and produced 20% less milk with 52.7% greater milk fat percentage during 28 to 140 d of lactation than heifers fed the high energy ration. Prepartum, animals of the high line had similar adipocyte volume and density to low line animals. However, during early lactation, high line animals had a greater decrease in volume and a larger increase in density than low line animals. There was a delayed recovery of volume in high line, compared with low line animals in late lactation. Adipocyte volume also was decreased by dietary energy restriction. Hormone-sensitive lipase activity was similar in both genetic lines prepartum and increased in all groups at 60 d postpartum. Animals of high line or fed low energy rations had increased activity per gram during early, but not later, lactation. Activity per cell and per milligram cytoplasm protein increased in all groups in early lactation and were highest in high line animals fed the low energy ration.

Adipose Tissue↗
PubMed1989

Formation of cyclic 1,N2-propanodeoxyguanosine and thymidine adducts in the reaction of the mutagen 2-bromoacrolein with calf thymus DNA.

The interaction of the mutagen 2-bromoacrolein (2BA) with DNA and thymidine was studied in vitro by reaction of [3-3H]2BA with thymidine, RNA, single-stranded DNA, and double-stranded DNA in phosphate buffer (pH 7.4). After purification of the nucleic acids, they were incubated at alkaline pH to convert any (hydroxybromo)propano(deoxy)-guanosine adducts to their dihydroxy analogues. After acid or enzymatic hydrolysis, the hydrolysates were analyzed by reversed-phase high-performance liquid chromatography. At a concentration of 1.6 mM, the fraction of 2BA that became covalently bound to DNA was 2.3% of the amount added. Only 3% of the radioactivity bound to DNA after extensive purification could be accounted for as cyclic 1,N2-(6,7-dihydroxy)-propanoguanine adducts. More 2BA became covalently bound to single-stranded DNA and RNA as compared with double-stranded DNA. However, high-performance liquid chromatographic analyses showed that formation of cyclic 1,N2-(6,7-dihydroxy)propanoguanine adducts was also a minor reaction with these macromolecules. Because these data showed that other type(s) of reaction(s) are more important in the reaction of 2BA with nucleic acids, we have investigated the reaction of 2BA with other nucleosides. It was found that 2BA reacted well with thymidine in vitro, and the major product was identified by 500 MHz 1H and 75.43 MHz 13C nuclear magnetic resonance and thermospray mass spectrometry as 3-(2"-bromo-3"-oxopropyl)thymidine. This adduct was unstable and decomposed upon storage. After enzymatic hydrolysis of [3H]2BA-modified double-stranded DNA and subsequent analysis of the hydrolysate by high-performance liquid chromatography, 22% of the covalently bound radioactivity to DNA coeluted with decomposition products of the 3-(bromooxypropyl)thymidine adduct. This indicates that reaction of 2BA with this nucleotide in DNA is a major reaction.

Acrolein↗
PubMed1989

Promotion of patient appointment compliance in indigent pediatric medical care by use of a microcomputer.

A computerized system for appointment scheduling, medical record keeping, medical billing, patient tracking, and epidemiologic data generation was developed and applied in an indigent pediatric otologic clinic. Functions used to augment appointment compliance are 1) notifying the referring physicians, agencies, and health department coordinators of failed appointments and sending medical information on the attended appointments, 2) listing patients who failed appointments, 3) production of mailings for failed appointments, 4) automatic rescheduling of failed appointments, and 5) automatic calculation of patient attendance ratios. The attendance ratio can be used to help identify patients for referral to social service workers and to implement rewards designed to promote medical compliance. The automatic rescheduling of failed appointments resulted in 21% of new patients and 30% of return patients above controls returning for a medical visit. The recalled had much lower economic status than our average clinic patient, ie, the system was effective in reaching the target population.

Ambulatory Care Information Systems↗
PubMed1987

CT demonstration of a giant colonic diverticulum.

A case of giant sigmoid colonic diverticulum (GCD) is presented in which plain films showed an unchanging persistent large gas collection that did not opacify on barium enema. The computed tomographic scan revealed the GCD in close apposition to the adjacent sigmoid diverticulosis. Its walls were thin and more irregular than noted on plain films, and there was a suggestion of intraluminal contrast within it.

Aged↗
PubMed1979

Intraocular reticulum cell sarcoma: a case report and literature review.

A 66-year-old white woman with a confusing spectrum of central nervous system signs and symptoms had a diagnostic enucleation of her blind left eye showing retinal infiltration. Histopathologic examination showed reticulum cell sarcoma involving the retina. The patient died one month later and autopsy revealed diffuse central nervous system reticulum cell sarcoma along with right eye and systemic involvement. A review of the literature indicates intraocular reticulum cell sarcoma to be an apparently uncommon occurrence, although ocular examination may be frequently overlooked.

Aged↗
PubMed1979

Late diagnosis of choroidal malignant melanomas in eyes with clear media and low visual acuity.

Five patients seen in a one-year period with advanced malignant melanoma of the choroid in eyes with low visual acuity and clear media are reported. The low visual acuity appeared clinically to be antecedent to the malignant tumor; although in certain cases it may have been related to the occult melanoma, this was not appreciated clinically. Because of the low visual acuity, these patients did not have vision symptoms referable to the melanoma, and the malignancy was diagnosed late in its course. All five cases had extrascleral extension of the tumor at the time of surgical treatment; three are dead of metastatic disease, and two have undergone orbital exenteration with only brief follow-up periods. This experience suggests that eyes with clear media and low vision owing to presumably unrelated causes should undergo periodic examination to rule out the presence of a growing malignant melanoma and to prevent its late diagnosis.

Abdominal Neoplasms↗
PubMed1979

Vascular basophilia in ocular and orbital tumors.

The occurrence of vascular basophilia in ocular tumors has been a selective histologic feature of retinoblastomas. We recently observed a metastatic oat-cell carcinoma to the choroid which also demonstrated such a vascular hematoxyphilia. Histologic review of a variety of ocular and orbital metastatic carcinomas failed to yield a similar basophilic pattern. Examination of 100 consecutive retinoblastomas for vascular basophilia revealed an incidence of 6.0%. Similar material was not seen in any of 125 melanomas, including 10 with areas of necrosis. Histochemical studies showed the basophilic material to be DNA, and electron microscopy revealed the nuclear debris of pyknotic tumor cells to be continuous with identical material surrounding the adjacent blood vessels. The pathogenesis of vascular deposition of DNA in these two ocular tumors remains unclear. This finding most likely represents a form of tumor activity requiring comparatively healthy blood vessels to adequately precipitate liberated nucleic acids being filtered from the necrotic and degenerating tumor tissue.

Basophils↗