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Biomedical subjects

D Miller

Publications and source records attributed to D Miller.

At least 577 records · Page 32Linked to original sources
PubMed1985

Reversal of wound strength retardation by addition of insulin to corticosteroid therapy.

Corticosteroids are known to retard the healing of corneal stromal wounds as well as to have positive anti-inflammatory effects. This study was designed to see if the addition of insulin to dexamethasone, administered subconjunctivally bid, would maintain dexamethasone's anti-inflammatory effect without inhibiting the healing (as measured by the wound bursting pressure) of a laboratory-inflicted 3-mm through-and-through central incision in the rabbit cornea. The results of a study involving 43 animals (86 eyes) showed the wounds to be significantly stronger in the insulin/dexamethasone-treated eyes than in the dexamethasone-treated eyes. The same anti-inflammatory effect was achieved with either protocol. Its mechanism of action is undetermined.

Administration, Topical↗
PubMed1985

A new lid sign in seventh nerve palsy.

This paper describes a new lid sign in two patients with facial nerve paralysis. The facial nerve palsy was secondary to a pontine abscess in the first case and a complication of acoustic neuroma resection in the second patient. Both patients were found to have absence of the normal nasal twist of the lower lid during eyelid closure. The nasal twist is felt to help pump tears into the lacrimal drainage system. This paper will describe the absence of an important eyelid function in a patient with facial nerve paralysis. By way of background, Doane's slow motion movies have shown that during a normal blink, the upper lid moves both down and nasally, while the lower lid moves from 2 to 5 mm nasally. As the upper lid descends, the lower lid normally moves 2 to 5 mm in a horizontal and nasal direction. This motion of the lower lid helps produce a partial vacuum in the lacrimal system and is responsible for moving the fluid and debris in the tear mentiscus across the eye and into the lacrimal drainage system. The two cases of facial nerve paralysis to be presented demonstrate absence of tear drainage on the side of the lesion and a build-up and overflow of the tears on that side.

Abscess↗
PubMed1985

The effect of a 550 nm cutoff filter on the vision of cataract patients.

The effect on visual function of an optical filter which absorbs essentially all visible wavelengths below 550 nm has been studied in a group of patients with moderate stage cataracts. Using a Snellen-type visual acuity chart with a blue background and orange letters, under both glare and non-glare conditions, the visual acuity of these patients was determined. Improvement in acuity was more striking under glare conditions than under standard (non-glare) conditions; in the former case it reached levels as high as 300% in a few patients. The level of the improvement seemed to be related both to cataract type and stage of cataract progression.

Cataract↗
PubMed1985

Male homosexuality and sexual problems.

Homosexual men are increasingly seeking help with sexual problems. A few seek to change their orientation and there is evidence that, for some people at least, this is possible. However the major reason for seeking help is sexual dysfunction which is treatable in homosexual men in the same way as in heterosexuals.

Ejaculation↗
PubMed1985

A re-appraisal of the development of the anterior chamber.

The development of the anterior chamber passes through distinct well orchestrated phases. It is a dynamic transition from an embryonic cleft to the adult anterior chamber. The cornea, lens, tunica vasculosa lentis, the iris, the ciliary epithelium, and the trabecular meshwork all play important roles in the development of the anterior chamber. Apart from these morphological changes that occur, the hydrodynamics of the transudate (from the tunica vasculosa lentis) and the aqueous humor from the ciliary epithelium appear to be essential components in the maintenance of the integrity of the anterior and posterior chambers.

Anterior Chamber↗
PubMed1984

Subacute and chronic myelomonocytic leukemia in children (juvenile CML). Clinical and hematologic observations, and identification of prognostic factors.

The clinical and hematologic characteristics of 38 children with subacute and chronic myelomonocytic leukemia (S & CMMOL) are described, and the prognostic significance of these characteristics as recorded at diagnosis is reported. The common and distinctive feature of these children was the excessive proliferation of cells of neutrophilic and monocytic series. The disease predominated in younger children, 95% were younger than 4 years, and boys were more affected than girls (22/16). The onset of the disease was heralded most often by acute or subacute symptoms. Splenomegaly was the most common physical finding at diagnosis. Leukocytosis was usually under 100 X 10(9)/l. Monocytosis and granulocytosis were often associated with normoblastosis, and, in some cases, with moderate blastosis (less than or equal to 30%). Severe anemia and marked thrombocytopenia were found in about one third of patients, increased fetal hemoglobin levels in 53%, and increased gamma-globulin levels in 50% of cases. The Philadelphia chromosome was absent in all blood and marrow cell karyotypes. Thirty-three of 38 patients were treated with moderate or intensive chemotherapy, and in all cases treatment never resulted in a complete remission. Terminal acute leukemia occurred in 11 cases. Of the 38 patients, 29 have died (median survival time, 16 months). Initial characteristics predicting a short survival (log-rank test) included: older age (greater than or equal to 2 years) (P less than 0.001), hepatomegaly (P less than 0.05), bleeding (P less than 0.001), thrombocytopenia (P less than 0.01), high counts of blasts and normoblasts in peripheral blood (P less than 0.01, P less than 0.01). Sex, infections, cutaneous manifestations, lymphadenopathy, degree of splenomegaly, hemoglobin levels, fetal hemoglobin, leukocyte counts, percent of blasts in bone marrow, and serum gamma-globulin levels were of no prognostic value. When survival was plotted on a semilogarithmic scale, a change in death rate was evident at the second year of survival suggesting that there may be two subgroups of patients with myelomonocytic picture, one with very rapid, and another with a slower rate of mortality. A stepwise discriminant-function analysis was performed in an attempt to distinguish between those children who lived less than or equal to 2 years and those who lived longer. A linear combination of variables which best discriminated between these two subgroups was found. Nearly all patients could be classified as a short-survivor or long-survivor on the basis of age and platelet, blast, and normoblast counts in peripheral blood.(ABSTRACT TRUNCATED AT 400 WORDS)

Bone Marrow Examination↗
PubMed1984

Effect of a sulfonium analog of dopamine on the depolarization-induced release of [3H]acetylcholine from mouse striatal slices.

P3 have synthesized a chemical analog or dopamine in which the amino group has been replaced by a charged dimethylsulfonium group. The dopaminergic activity of this drug was evaluated by determining its ability to inhibit the depolarization-evoked release of [3H]acetylcholine from mouse striatal slices. The slices were preincubated with [3H]choline (0.1 microM) and then superfused in physiological medium. [3H]Acetylcholine release was induced by exposure of the slices to a high potassium medium (12.5 mM) for 5 min. The sulfonium analog of dopamine, dopamine, and apomorphine inhibited the evoked [3H]acetylcholine release with IC50 values of approximately 10, 2.0, and 0.3 microM respectively. The inhibition by the sulfonium analog was reversed by fluphenazine (1 microM), suggesting that the inhibition of [3H]acetylcholine release was due to the activation of dopaminergic receptors. The sulfonium analog also inhibited the uptake of [3H]dopamine into striatal slices and caused the release of exogenously taken up [3H]dopamine from these slices. The release of [3H]dopamine by the sulfonium analog was inhibited by cocaine (3 microM), suggesting that the drug-induced release of [3H]dopamine was dependent on the carrier-mediated uptake of the sulfonium analog into dopaminergic neurons. The inhibition of the evoked [3H]acetylcholine release by high concentrations (30 and 60 microM) of the sulfonium analog did not appear to be mediated by endogenous dopamine release, since the analog still inhibited [3H]acetylcholine release from slices after reserpine-alpha-methyl-p-tyrosine treatment. However, the inhibitory effect of the sulfonium analog at 10 microM was reduced by reserpine-alpha-methyl-p-tyrosine treatment, suggesting that the inhibition at lower concentrations was mediated through endogenous DA release. These results suggest that a charged compound can act as a substrate for the dopamine carrier and can activate the dopamine receptor regulating acetylcholine release. They also indicate that the nitrogen on the dopamine molecule is not essential for dopamine agonist activity.

Acetylcholine↗
PubMed1984

Effect of 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) on monoamine neurotransmitters in mouse brain & heart.

The effect of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was studied on dopamine (DA), norepinephrine (NE), serotonin (5HT) and gamma-aminobutyric acid (GABA) neurons in mouse brain and on NE neurons of mouse heart. MPTP (45 mg/kg) was administered s.c. to mice twice daily for 2 consecutive days. This dosage regimen produced a decrease in the forebrain concentrations of DA and NE at 7 and 20 days after injection. In contrast, the forebrain concentrations of 5HT and GABA were not significantly decreased at either time. MPTP administration also produced a marked decrease in the uptake of 3H-DA into striatal slices and 3H-NE into cerebral cortical slices. In contrast, the uptake of 3H-NE into hypothalamic slices and the uptake of 3H-5HT into slices from several brain regions were not altered. MPTP initially reduced the concentration of NE in the heart, but unlike the persistent decreases in the forebrain concentrations of NE and DA, the NE concentration in the heart returned to control levels at approximately 20 days after MPTP administration. These results, showing that MPTP can produce a long lasting and selective decrease in the forebrain concentrations of NE and DA and in the uptake of radioactive DA and NE into brain slices, suggest that MPTP can cause the destruction of catecholamine neurons in mouse brain. In contrast, MPTP administration does not appear to produce long term changes in either 5HT or GABA neurons.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1984

Reutilization of phosphatidylcholine analogues by the pulmonary surfactant system. The lack of specificity.

Five specific 14C-labelled analogues of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, (L-alpha-DPPC) including 1-palmitoyl-sn-glycero-3-phosphocholine, (L-alpha-lysoPC) and 2,3-dipalmitoyl-sn-glycero-1-phosphocholine (the D isomer of DPPC) were individually mixed with L-alpha-[3H]DPPC and unlabelled natural surfactant isolated from 3-day-old rabbits. The mixtures were injected intratracheally into 3-day-old rabbits which were then killed at preset times up to 72 h after injection. Phosphatidylcholine was isolated from the alveolar wash and from lamellar body fraction from each rabbit and was analyzed for the ratio of 3H-to-14C counts/min. These ratios were plotted against the time the rabbits were killed to determine whether a difference existed in the rates of reutilization of the analogues relative to L-alpha-DPPC. By 60 h L-alpha-lysoPC was reutilized at 42% of the efficiency of the L-alpha-[3H]DPPC with which it was injected. That part of the L-alpha-lyso which was reutilized had been converted to [14C]phosphatidylcholine. Each of the other four analogues was reutilized by the surfactant system as efficiently as L-alpha-DPPC. These results are most consistent with a process of bulk uptake of surfactant from the alveolar space by the Type II cell with subsequent processing for resecretion which involves minimal specificity for molecular structure.

Animals↗
PubMed1984

Shear flow characteristics of sodium hyaluronate. Relationship to performance in anterior segment surgery.

In this study, methods were developed for the in vitro evaluation of the surgical performance characteristics of viscoelastic fluids, such as sodium hyaluronate (Healon). Sodium hyaluronate exhibited superior surgical performance to chondroitin-6-sulfate. The superior performance of sodium hyaluronate resulted in part from its high viscosity, which is 20 times greater than that of chondroitin-6-sulfate at shear rates on the order of 10 s-1. The gel-like character of sodium hyaluronate as evidenced by the creep flow behavior, was greater than that of chondroitin-6-sulfate and was important for maintaining depth in the anterior chamber. It was shown that a threshold of 80 poise for the shear viscosity (at approximately 10 s-1 was needed for useful performance in surgery. It was also shown that 0.42 USP units of hyaluronidase per 1.0 mg sodium hyaluronate produces a 90% decrease in the shear viscosity (at approximately 10 s-1) within approximately 2 1/2 hours. Use of sodium hyaluronate in conjunction with hyaluronidase would allow sodium hyaluronate to remain highly viscous during surgery, but would gradually become less viscous to facilitate aqueous outflow after surgery.

Animals↗
PubMed1984

Clinical performance of a disability glare tester.

A glare tester was described previously and was found, in the presence of cataracts, to be almost twice as predictive as was Snellen measurement for determining visual acuity outdoors. The current study tests the reproducibility of glare test scores and the influence of refractive error and contrast sensitivity on such scores when used in a clinical environment. Although the effects of visual acuity and impaired contrast sensitivity were found to be statistically significant components of glare test scores, the magnitudes of their effects were found to be clinically insignificant. Sequential retesting of physiologically stable eyes or, in the case of progressive cataracts, within intervals short enough to preclude discernible lenticular changes indicated that, for the most part, reproducibility of glare testing was comparable to that of visual acuity testing.

Adult↗
PubMed1984

Advanced squamous carcinoma of the head and neck. A preliminary report of neoadjuvant chemotherapy with cisplatin, bleomycin, and methotrexate.

Between Oct 1, 1979 and Aug 1, 1982, 93 patients with advanced squamous carcinoma of the head and neck were given neoadjuvant treatment with cisplatin, bleomycin sulfate, and methotrexate before standard local treatment. Ninety-three patients were evaluable for response. The response rates were as follows: complete response, 24%; partial response, 64%; and no response, 12%. Differences in primary tumor site, performance status at presentation, histologic grade, and tumor size did not correlate with response to this chemotherapy. For patients achieving notable tumor reduction to 2 cm or less, standard local treatment with either surgery plus radiotherapy or high-dose radiotherapy alone was effective in controlling local disease. For patients with larger tumor masses following neoadjuvant chemotherapy, surgical resectability appeared to improve local control rates. In our series, patients not receiving maximal standard local treatment often had relapse of local disease despite favorable responses to chemotherapy.

Adolescent↗
PubMed1984

Ventricular arrhythmias during ergonovine-induced episodes of variant angina.

Of 95 consecutive patients with active variant angina who underwent ergonovine testing in the coronary care unit while off treatment, 24 (25%) developed serious ventricular arrhythmias: ventricular tachycardia in eight, bigeminy in seven, pairs in five, and frequent ventricular extrasystoles in four. Ergonovine-induced arrhythmias were observed more often in patients with anterior than inferior ST segment elevation (p less than 0.05). ST segment elevation was significantly higher (10.3 +/- 8.1 vs 3.1 +/- 2.1 mm) in patients who developed arrhythmias. All ventricular arrhythmias began within 3 minutes after the onset of ST segment elevation. The intravenous administration of nitroglycerin eliminated arrhythmias in 22 of 24 cases; in only two patients did ventricular arrhythmias develop after the administration of nitroglycerin. Serious ventricular arrhythmias were found during spontaneous variant angina attacks in 14 of 24 patients with ergonovine-induced arrhythmias compared to 16 of 71 patients without ergonovine-induced arrhythmias (p less than 0.001). We conclude that arrhythmias during ergonovine testing are most often caused by ischemia and not reperfusion. Patients with arrhythmias during ergonovine-induced attacks are more likely to have arrhythmias during spontaneous attacks.

Adult↗
PubMed1984

High-speed photographic evaluation of intraocular lens movements.

Iridodonesis and pseudophakodonesis were examined in detail with a high-speed camera capable of picture rates up to 500/sec. Tilting, or "wobble," of iris-supported intraocular lenses was extreme, with a tilt of nearly 24 degrees with respect to the visual axis of the globe being documented, even with a moderate speed of globe rotation. Oscillations of the lens continued for several cycles after the globe stopped its rotation. Such lenses can, in some instances, tilt sufficiently to contact the endothelial surface of the cornea. In the case of some anterior chamber intraocular lenses, the iridodonesis is sufficient to cause constant rubbing of the iris on the posterior surface of the lens and its haptics , suggesting that vault, finish, haptic configuration, and placement of the lens may be critical factors in anterior chamber intraocular lens design.

Cataract Extraction↗
PubMed1984

Early reconstruction of Poland's syndrome using autologous rib grafts combined with a latissimus muscle flap.

The complex chest wall deformity of Poland's Syndrome may require intervention in early childhood for missing ribs and paradoxical movement of the involved anterior chest with lung herniation. To stabilize the chest wall, we have used autologous rib grafts and prosthetic fabric to replace absent endothoracic fascia. While physiologically sound, this method does nothing for the cosmetic defect which consists of absence of the pectoralis minor and one half to two thirds of the pectoralis major muscles. Silastic implants are not satisfactory in childhood and have complications from recurrent trauma and mobility in young adults. We have had recent experience in three patients (ages 10, 14, and 16 years) with an original technique which results in chest wall stabilization and immediate cosmetic reconstruction without prostheses. The operation utilizes simultaneous rib grafts and a rotational latissimus muscle flap. The muscle not only produces a near-normal contour, but also maintains sensation and contractile function. We propose this technique as a method of choice for the correction of Poland's Syndrome and suggest that it may have wider application in children and teenagers who need soft tissue and muscle replacement of the chest wall for other reasons.

Adolescent↗