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Biomedical subjects

W A Miller

Publications and source records attributed to W A Miller.

At least 109 records · Page 6Linked to original sources

Amniotic fluid gel cholinesterase density ratios in fetal open defects of the neural tube and ventral wall.

Densitometry was used to measure gel acetyl- and pseudocholinesterase bands in a selection of amniotic fluid samples yielding positive alpha-fetoprotein and positive gel acetylcholinesterase results. The samples were associated with the following conditions: 28 anencephaly (10 stained with fetal blood), 20 open spina bifida (3 stained with fetal blood), 10 open ventral-wall defects (2 stained with fetal blood) and 5 unaffected pregnancies (all stained with fetal blood). In samples not visibly stained with fetal blood, the ratio of the acetylcholinesterase density to the pseudocholinesterase density distinguished between open ventral-wall defects and open neural-tube defects: the former group all had values less than 0.13, while the latter all had values greater than that. In amniotic fluid samples which were stained with fetal blood the acetylcholinesterase/pseudocholinesterase ratio did not offer useful diagnostic information; results from unaffected pregnancies overlapped with those from pregnancies with both ventral-wall defects and open neural-tube defects.

Acetylcholinesterase↗

Dysgenesis of testicular and streak gonads in the syndrome of mixed gonadal dysgenesis: perspective derived from a clinicopathologic analysis of twenty-one cases.

The clinical and pathologic aspects of 21 cases of mixed gonadal dysgenesis (MGD) were studied. The gonads in 15 patients consisted of a macroscopic testis and a streak gonad; six patients had variants, including two with bilateral testes and four with bilateral streak gonads or tumors. Functionally, the gonads were incompetent. Testes 1) failed to completely inhibit müllerian development, 2) failed to support full differentiation of mesonephric duct structures, 3) failed to adequately masculinize development of the external genitalia, or 4) often failed to mediate their own descent, resulting in asymmetry of the internal and external genitalia. None of the streak gonads mediated normal female adolescent development or fertility. Microscopic examination revealed that every gonad, regardless of its gross appearance, was morphologically abnormal. Although gonads with seminiferous tubules usually developed to a moderately advanced state, macroscopically resembling testes, the hilar zone remained architecturally disorganized; the cortex invariably lacked more than a rudimentary tunica albuginea or exhibited partial ovarian differentiation, sometimes even with a rare primordial follicle. Over time, the seminiferous tubules atrophied and hyalinized. Gonads that grossly resembled streak gonads were observed microscopically to be composed of a stroma resembling that of normal ovarian cortex. In patients more than several years of age, the entire complement of germ cells in streak gonads disappeared. It is suggested that patients with MGD be raised as females. Early removal of gonads will prevent the development of gonadoblastoma and dysgerminoma. If the uterus is retained and the patient is subsequently given exogenous estrogen, care should be taken to detect early any signs of the development of endometrial carcinoma or its precursor, to which these patients may be prone.

Adolescent↗

Cartilaginous sesamoid or nodule of the interphalangeal joint of the big toe.

Since 1971, a cartilaginous sesamoid or nodule has been identified in the plantar ligament of the interphalangeal joint of the big toe in 29 of the 58 patients (50%) from whom spurs of the plantar medical aspect of the adjacent phalanges were removed because of painful callouses. It is felt that the firm mass of the cartilaginous sesamoid may have contributed to the callous formation in many cases. These cartilaginous sesamoids have all been removed when found.

Adult↗

Role effectiveness of a pharmacist in the maintenance of patients with hypertension and congestive heart failure.

This study was designed to measure the role effectiveness of pharmacists in the management of patients with hypertension and congestive heart failure. Based on therapy protocols established by physicians and pharmacists prior to the study, the pharmacist was measured against the standard for providing primary care--i.e., the physician. The study showed that the pharmacist competently elected drug therapy and identified adverse drug reactions. As a group, the 20 study patients, whose therapy was determined by the pharmacist, were better managed than the 20 control patients (p less than 0.05). It is suggested that the pharmacist is effective in the role of managing patients with hypertension and congestive heart failure.

Clinical Competence↗

Histochemistry of lower vertebrate calcified structures. I. Enamel of the dogfish Squalus acanthius compared with mammalian enamel and homologous dentine.

The enameloid and dentine of Squalus acanthius have been compared histochemically with those of Bos taurus. Squalus enameloid is much less reactive to a variety of stains or reagents than dentine or bovine immature enamel but it does have positive reactions with picromethyl blue, Mallory's and Van Gieson's stains, and Alcian blue. It stains faintly with Biebrich scarlet, indicating some anionic groups. Specific reactions for tyrosine, tryptophane, lysine, histidine, arginine, and cysteine are negative. Bos immature enamel is positive for cationic, anionic, and aromatic reactive groups by all test procedures, and dentine was positive for the anionic components. Bovine maturing enamel, however, is more similar in terms of lack of reactivity to Squalus enameloid but differed because the bovine enamel was moderately positive for tyrosine; tryptophane, and anionic groups and negative with Mallory's picromethyl blue and Van Gieson's stains. A fibrous transitional area between Squalus dentine and enameloid has staining reactions characteristic of both collagen and keratins.

Animals↗

Atypical fibromuscular hyperplasia. Report of two cases.

Two cases of atypical fibromuscular hyperplasia of the internal carotid artery (ICA) are reported. These cases are unique because the changes involve the intima of the vessels without involvement of medial structures as seen in the more common form of fibromuscular hyperplasia. Case 1 is only the fourth report of a symptomatic fibromuscular stenosis at the origin of the ICA. Case 2 is the first report of fibromuscular hyperplasia involving the common carotid artery. Changes similar to those in Case 2 (an elongated area of tubular fibromuscular stenosis) have been reported in the ICA. These atypical or intimal forms of fibromuscular hyperplasia appear to be more common in males and blacks, and may be more often unilateral as well.

Aged↗

Acetylcholinesterase and fetal malformations: modified qualitative technique for diagnosis of neural tube defects.

A single-blind study involving amniotic-fluid samples from 214 pregnancies of known outcome confirms that an electrophoretically distinct isoenzyme of acetylcholinesterase is associated with fetal open neural tube defects. Furthermore, only one of 13 amniotic-fluid samples with false-positive results for alpha-fetoprotein showed the characteristic isoenzyme, indicating that qualitative acetylcholinesterase assessment can decrease the proportion of false positives from the alpha-fetoprotein assay. We have also identified this characteristic isoenzyme in amniotic fluids from pregnancies in which other serious fetal defects occurred. A detailed electrophoresis protocol for identifying this characteristic isoenzyme is described.

Acetylcholinesterase↗

Three metronidazole-resistant strains of Trichomonas vaginalis from the United States.

Trichomonas vaginalis isolates were obtained in the United States from three women with trichomoniasis refractory to routine treatment with metronidazole. Cure was obtained in these cases with increased dosage of metronidazole. In experimental mouse infections, all three strains showed a significantly (about 10 to 20 times) lower susceptibility to metronidazole than did a number of control strains. In vitro, the lowered susceptibility could be detected only in an aerobic assay but not in the routine anaerobic assay. The conclusion is that T. vaginalis strains with lowered metronidazole susceptibility do exist. Such strains might be responsible for a certain, but as yet entirely unknown, number of failures in routine metronidazole therapy of human trichomoniasis.

Adult↗

Dental root abnormalities and gingival overgrowth in epileptic patients receiving anticonvulsant therapy.

Forty-six mentally retarded epileptic patients being treated with phenytoin and phenobarbital were studied to determine the root/crown length ratios. Forty-five mentally retarded patients not receiving anticonvulsant drugs provided the controls. Further, because serum phenytoin levels have been related to severity of gingival hyperplasia, efforts were made to determine if the hyperplasia was associated with dental root abnormalities and also whether these abnormalities could be related to epilepsy per se. Results showed that in certain teeth there was a smaller root/crown ratio in the patients taking anticonvulsant medication. The male patients were more affected than the female. The unusually short roots were not necessarily related to high serum phenytoin but the severity of gingival overgrowth was. Histologic study of teeth from patients taking anticonvulsants revealed developmental abnormalities and resorption.

Adolescent↗

Enamel matrix proteins in normal and abnormal amelogenesis.

Histochemical techniques have been used to study three stages of enamel maturation in normal (fetal calf, newborn human, adult human) and abnormal amelogenesis (odontodysplasia, fluorosis, a compound-complex odontome, and an invaginated odontome). The amount of Type I matrix secreted decreases as amelogenesis progresses. Pockets of Type II matrix may be left at the dentino-enamel junction after maturation of enamel to Type III. Fluorosed enamel contains pockets which may extend the width of the enamel. All stages of enamel maturation may be seen in the compound-complex odontoma.

Amelogenesis↗

Audit of anticoagulant therapy of pulmonary embolus, deep vein thrombosis and thrombophlebitis.

The use of heparin sodium and warfarin sodium in the treatment of pulmonary embolus (PE), deep vein thrombosis (DVT) and thrombophlebitis (TP) was studied by a hospital pharmacy department. During a four-month period, the charts of 26 patients were audited for anticoagulant dosages used; laboratory test monitoring of anticoagulant dosage used; laboratory test minitoring of anticoagulant therapy; complications of, contraindications to, and patient compliance with anticoagulant therapy. These variables were evaluated on the basis of compliance with a written anticoagulant protocol. Initial doses of heparin sodium and warfarin sodium were acceptable in 43% of patients. Maintenance dosing with heparin sodium was acceptable in 89% of patients. Activated partial thromboplastin times (APTT) were ordered correctly for 65% of patients. APTTs were within therapeutic ranges in 31% of patients. The duration of heparin-warfarin overlap was possibly to definitely acceptable in 71% of patients. Prothrombin times were properly monitored in 50% of patients. Complications of anticoagulant therapy were evident in only one patient. There were a number of potentially serious diversions from the protocol. The pharmacy department planned to issue bulletins designed to correct the problems.

Adult↗

The relationship of the accessory navicular to the development of the flat foot.

The Kidner procedure has been the most frequently recommended form of surgical treatment for the painful accessory navicular. This formal relocation of the posterior tibial tendon is said to restore the dynamic balance to the foot which is lost when the posterior tibial tendon gives an abnormal insertion into the accessory ossicle. The literature was reviewed to ascertain what is known or what is believed about the accessory navicular and the role of the posterior tibial tendon in the support of the longitudinal arch of the foot. Eighteen patients who had simple excision of the accessory navicular were reviewed to assess the success of such a procedure. In follow-up they all had very satisfactory results. A second group of 208 patients with non-traumatic foot complaints were reviewed to determine the incidence of accessory navicular and its association with the flat foot. Twenty-nine cases of previously undetected accessory navicular were identified in this group giving us a total of 179 patients without accessory navicular and 49 patients with accessory navicular available for study. There was no significant difference between the arch in these 2 groups of patients. Based on the findings in this study, the accessory navicular plays no role in the development of a flat foot. Simple excision of the prominent ossicle seems to be the surgical procedure of choice when conservative means of management fail.

Adult↗