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Biomedical subjects

H Lewis

Publications and source records attributed to H Lewis.

At least 127 records · Page 7Linked to original sources
PubMed1988

The effects of flosequinan and nifedipine on glucose tolerance in healthy volunteers.

The influence of flosequinan and nifedipine on glucose tolerance has been investigated in a placebo-controlled four-way crossover study in 12 healthy volunteers. There was no statistical difference between the glucose tolerance curves after placebo, a single dose of flosequinan, chronic treatment with flosequinan or nifedipine at steady state. Headache was more frequent in volunteers on flosequinan than after either nifedipine or placebo.

Adult↗
PubMed1988

Alcohol and treatment of diabetes.

The effects of alcohol on diabetic patients controlled on insulin are reviewed and the associated risks of hypoglycaemia, insulin resistance and ketosis are commented on. The impact of alcohol intake in patients with maturity onset diabetes is also considered and potential interactions with oral hypoglycaemic agents highlighted.

Alcohol Drinking↗
PubMed1988

Cephalosporin-induced changes in the ultrastructure of canine bone marrow.

Fourteen healthy dogs were given 540 to 840 mg/kg of cefazedone (Refosporen) intravenously for up to 4 months or until peripheral blood cell count were depressed. Within 6 to 10 weeks treated dogs developed pancytopenia (5/14), thrombocytopenia (11/14), moderate to severe neutropenia (8/14), and/or normocytic anemia with erythroblastemia (8/14). Ultrastructural changes in bone marrow of severely cytopenic dogs included mitochondrial damage in hematopoietic and nonhematopoietic cells, thickening of endosteal bone lining layers, increased adventitial coverage of vascular sinuses, and an increased number of active macrophages. Swollen, ruptured mitochondria were in erythroid, granulocytic, and megakaryocytic cells, and, to a lesser extent, in macrophages, reticular endothelial, and bone lining cells. Maturation arrest was evident in both erythroid and granulocytic cell lines. There was also evidence of ineffective erythropoiesis and granulopoiesis. None of these changes were observed in bone marrow of controls, treated dogs that did not develop cytopenia, or dogs allowed to recover after cessation of dosing.

Anemia↗
PubMed1988

Reproducible cloning assays for in vitro growth of canine hematopoietic progenitor cells and their potential applications in investigative hematotoxicity.

A variety of in vitro cloning assays have been used for studying hematopoiesis in mice and human beings. However, these techniques have had limited use in dogs, a species used extensively as a model for hematopoietic research, particularly hematotoxicity. We have adopted cloning assays for in vitro growth of canine colony-forming unit-erythroid (CFU-E) and colony-forming unit-granulocyte/macrophage (CFU-GM) progenitor cells, using modified microplasma clot and soft agar culture systems, respectively. Marrow mononuclear cells separated by density-gradient centrifugation were added to the aforementioned culture systems. Erythroid colonies were stimulated with sheep plasma erythropoietin and incubated at 37 C in 5% CO2 for 2 days. The CFU-E colonies were fixed with 5% glutaraldehyde, stained with benzidine, counted, and expressed as a mean of 8 replicates. The CFU-GM colonies were stimulated with pooled serum from endotoxin-treated dogs and incubated for 8 days at 37 C in 10% CO2. Using an inverted microscope, the CFU-GM colonies were counted and expressed as a mean of 6 replicates. The number of colonies was proportional to the plated cell concentrations. The addition of 10% autologous serum to CFU-GM cultures increased the number of colonies by 80 to 100%, but markedly reduced the size and number of CFU-E colonies. The marrow cloning capacity among dogs of comparable age was similar, and little variation was noticed when bone marrow cells from the same dogs were cultured repeatedly over a period of 3 to 4 months. We concluded that these cloning assays are fast, reliable, and reproducible and that they allow quantitative determination of canine hematopoietic progenitor cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Anterior hyaloidal fibrovascular proliferation after diabetic vitrectomy.

Vitrectomy was performed to treat 74 consecutive eyes for complications of diabetic retinopathy. Eight (13%) of 61 eyes followed up for an average of 12 months developed anterior hyaloidal fibrovascular proliferation. This was the most common postoperative complication, whose features included recurrent hemorrhages into the vitreous cavity or anterior vitreous, or both; vessels or fibrovascular tissue on the posterior lens capsule; anterior extraretinal vascularization extending toward the lens on the anterior hyaloid; traction detachment of the peripheral retina or ciliary body; and hypotony. Patients who developed this complication tended to be young males with severe retinal neovascularization and extensive retinal ischemia; traction retinal detachment as an indication for surgery; placement of a scleral buckle; postoperative rubeosis iridis, recurrent vitreous hemorrhages, and retinal detachment; and multiple surgeries. Four eyes progressed to atrophia bulbi. Early recognition followed by additional surgery in two patients and extensive additional photocoagulation in two other patients was successful in preserving good visual function.

Adult↗
PubMed1987

Clinicopathologic findings in anterior hyaloidal fibrovascular proliferation after diabetic vitrectomy.

Two young patients (27 and 30 years old, respectively) with long-standing diabetes mellitus underwent vitreoretinal surgery for traction retinal detachment and vitreous hemorrhage. The postoperative course in each was characterized by early recurrence of the hemorrhage into the vitreous cavity, hypotony, and severe visual loss. Histopathologic examination of both operated on eyes showed anterior extraretinal fibrovascular proliferation extending along the anterior hyaloid to the posterior lens surface, causing traction detachments of the peripheral retina and ciliary body. The vessels originated from the anterior retina. There was no evidence of excess fibrous tissue at the well-healed sclerotomy wounds.

Adult↗
PubMed1987

Young women's reproductive health survey.

A survey of reproductive health issues was conducted on 15 year old Hutt Valley secondary school girls by means of a self-administered anonymous questionnaire. The prevalence of sexual intercourse in the sample was 29%. Sixteen percent of the sexually active respondents used no method of contraception. Knowledge of reproductive health facts and contraception was poor both amongst sexually experienced and inexperienced respondents. Twenty-six percent relied on peers for this information, with mothers, teachers and books being other important sources cited. Respondents requested more information on sexually transmitted diseases, contraception and sexual relationships. Most would like this information more readily accessible. Preferred sources of information mentioned were: parents, books, films/videos, family planning clinics and friends.

Adolescent↗
PubMed1987

Intrusion of retinal tacks.

We examined nine patients in whom retinal tacks intruded into the eye and lodged in the subretinal space, preretinal space, vitreous cavity, or anterior chamber. Complications included retinal pigment epithelium atrophy; retinal phlebitis; vitreous hemorrhage; focal corneal, iris, and retinal injury; and corneal edema. The intrusion of the retinal tacks did not apparently cause, but was associated with retinal redetachment in five patients. Factors associated with intrusion of the retinal tacks included absence of a barb at the end of the tack to anchor it to the sclera, absence of a groove in the tack, a short shaft, incomplete penetration of the retina, choroid, and sclera by the tack, self-inflicted trauma to the eye, placing a scleral buckle after inserting the tacks, and reproliferation of periretinal membranes. In four patients the intruded tacks did not cause any complications. In four patients the intruded tacks were removed without complications and in the remaining five patients, they were left in the eye.

Adolescent↗
PubMed1987

Management of fibrin pupillary-block glaucoma after pars plana vitrectomy with intravitreal gas injection.

After pars plana vitrectomy and fluid-gas exchange, two patients developed fibrin membranes across the pupillary space resulting in pupillary block and subsequent glaucoma. In one case the angle was closed; in the second case the angle was open because of gas in the anterior chamber. In both cases the argon laser made permanent openings in the fibrin pupillary membrane that relieved the pupillary block.

Adult↗
PubMed1987

Laser photocoagulation in the acute retinal necrosis syndrome.

Acute retinal necrosis (ARN) is a syndrome of fulminant necrotizing vaso-occlusive retinitis associated with a high incidence of retinal detachment due to retinal breaks and vitreous traction. We performed argon or krypton laser photo-coagulation to demarcate areas of active retinitis as prophylaxis against retinal detachment in five patients with ARN. Patients were concomitantly treated with antiviral agents, systemic steroids, and antiplatelet therapy. One patient required multiple additional treatments as retinal necrosis progressed. The retinas remained attached in all five patients over a mean follow-up period of 15 months. By creating a chorioretinal adhesion in areas of potential retinal break formation, laser photocoagulation may be an effective prophylaxis against retinal detachment in ARN.

Acute Disease↗
PubMed1987

A prospective study of cystoid macular edema after neodymium: YAG laser posterior capsulotomy.

To establish the clinical and angiographic incidence of cystoid macular edema (CME) after neodymium:YAG (Nd:YAG) laser capsulotomy, the authors have prospectively studied 136 patients who underwent Nd:YAG laser discission for secondary opacification of the posterior capsule after extracapsular cataract extraction. In all patients, fluorescein angiography was obtained before the laser discission. Of the 136 patients, 78 (57%) were followed for at least 6 months, and fluorescein angiography was repeated 4 to 8 weeks after the procedure. CME did not develop in any of the patients in this series.

Adult↗
PubMed1987

Abolition of Holter monitor-detected silent myocardial ischemia after percutaneous transluminal coronary angioplasty.

Twenty-four hour Holter ambulatory electrocardiographic recordings were obtained before and after successful coronary angioplasty in 36 patients. Twenty-five patients had one vessel, 10 had two vessel and 1 had three vessel coronary artery disease. Holter monitor-detected myocardial ischemia, defined as ST segment depression or elevation greater than or equal to 1 mm, was present in 10 patients (28%). These 10 patients had a total of 39 ischemic episodes of 3 to 144 minutes' duration, with a total cumulative duration of 398 minutes. None of the 10 had Holter monitor-detected ischemia after successful angioplasty (p less than 0.01). Treadmill exercise duration increased by 29% after coronary angioplasty (p less than 0.01), and peak exercise heart rate-systolic blood pressure product increased by 27% (p less than 0.01). Thus, Holter monitor-detected myocardial ischemia is a relatively uncommon finding in patients with predominant single vessel coronary artery disease undergoing coronary angioplasty. When such ischemia is present, it is eliminated by successful coronary angioplasty.

Adult↗