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Biomedical subjects

H Schatz

Publications and source records attributed to H Schatz.

At least 91 records · Page 5Linked to original sources
PubMed1998

[Step-wise drug therapy in type 2 diabetes mellitus].

After diagnosis of type 2 diabetes mellitus, a careful education of the patient as well as diet consulting is necessary especially when body weight should be reduced. When these steps do not achieve an adequate metabolism, insulinotropic substances (sulphonyl urea or repaglinid) as well as biguanides and inhibitors of the disaccaridase (acarbose and meglitol) are available for further treatment. In the future, thiazolidindione may be applied which primarily increases the sensitivity for insulin. All these drugs may be combined with insulin application once or more often a day i.e. by the bolus principle. Mostly in older patients however, a conventional insulin therapy with a fixed daily rhythm has to be recommended when oral antidiabetic agents fail. When a patient asks for more flexibility, one should not hesitate to teach even the older patient the intensified insulin therapy.

Adult↗
PubMed1997

Deficiency of phosphofructo-1-kinase/muscle subtype in humans impairs insulin secretion and causes insulin resistance.

Non-insulin-dependent diabetes mellitus (NIDDM) is caused by peripheral insulin resistance and impaired beta cell function. Phosphofructo-1-kinase (PFK1) is a rate-limiting enzyme in glycolysis, and its muscle subtype (PFK1-M) deficiency leads to the autosomal recessively inherited glycogenosis type VII Tarui's disease. It was evaluated whether PFK1-M deficiency leads to alterations in insulin action or secretion in humans. A core family of four members was evaluated for PFK1-M deficiency by DNA and enzyme-activity analyses. All members underwent oral and intravenous glucose tolerance tests (oGTT and ivGTT) and an insulin-sensitivity test (IST) using octreotide. Enzyme activity determinations in red blood cells showed that the father (46 yr, body mass index [BMI] 22. 4 kg/m2) and older son (19 yr, BMI 17.8 kg/m2) had a homozygous, while the mother (47 yr, BMI 28.4 kg/m2) and younger son (13 yr, BMI 16.5 kg/m2) had a heterozygous PFK1-M deficiency. DNA analyses revealed an exon 5 missense mutation causing missplicing of one allele in all four family members, and an exon 22 frameshift mutation of the other allele of the two homozygously affected individuals. The father showed impaired glucose tolerance, and the mother showed NIDDM. By ivGTT, both parents and the older son had decreased first-phase insulin secretion and a diminished glucose disappearance rate. The IST showed marked insulin resistance in both parents and the older, homozygous son, and moderate resistance in the younger son. PFK1-M deficiency causes impaired insulin secretion in response to glucose, demonstrating its participation in islet glucose metabolism, and peripheral insulin resistance. These combined metabolic sequelae of PFK-1 deficiency identify it as a candidate gene predisposing to NIDDM.

Adult↗
PubMed1997

mRNA expression of ligands of the epidermal-growth-factor-receptor in the uterus.

Six different ligands of the epidermal-growth-factor receptor (EGFR) have been identified in the past. In some cervical squamous-cell carcinomas, an increased amount of proteins binding to the EGFR has been reported. In order to identify the mRNA of EGFR ligands (EGFRL), which might be overexpressed in cervical and endometrial cancers, we performed semi-quantitative reverse-transcription/polymerase chain reactions (RT-PCR) for all 6 EGFRL in RNA extracts of normal and malignant tissue samples of the human uterus. PCR products from RNA extracts of 83 patients were quantitated relative to the housekeeping gene and internal standard pyruvate dehydrogenase by analyzing the PCR kinetics of product synthesis. In extracts of normal cervix, the level of mRNA expression of the EGFRL was significantly higher than in endometrium. No significant difference was detected between normal cervix and cervical carcinomas. However, both in cervical and in endometrial cancers, mRNA expression was non-parametrically distributed and in some cervical cancers overexpression of transforming growth factor alpha (TGF-alpha), amphiregulin or EGF was observed. In endometrial cancers, mRNA levels of all EGFRL were higher than in normal endometrium. This increase was significant (p < 0.005) for TGF-alpha and amphiregulin. Thus, TGF-alpha mRNA is overexpressed in approximately 10% of cervical cancers and in the majority of endometrial cancers. Since TGF-alpha anti-sense therapy might represent a future strategy in such cancers, we also determined the absolute level of TGF-alpha mRNA expression by quantitative PCR using a cloned standard.

Cloning, Molecular↗
PubMed1997

Acute multifocal retinitis.

PURPOSE: To describe the clinical presentation, ophthalmoscopic and fluorescein angiographic findings, and natural history of 14 eyes in nine otherwise healthy, young-to-middle-age adults with idiopathic, acute, multifocal retinitis. METHODS: A retrospective review of the clinical and photographic records of nine patients. RESULTS: Five of the nine patients reported a flu-like illness 1 to 2 weeks before the onset of visual symptoms. Ophthalmoscopic findings included mild vitritis (11 of 14), mild optic nerve edema (seven of 14), macular star (two of 14) or localized neurosensory retinal detachment (two of 14) caused by adjacent focus of retinitis, and small branch-artery occlusion (two of 14). Fluorescein angiography showed early blocking hypofluorescence with late staining hyperfluorescence of all areas of retinitis. In patients with optic nerve edema, the disk showed late leakage. Specific tests for collagen vascular disorders, as well as systemic syphilis and toxoplasmosis titers, were negative in all patients. Five of six patients with histories of cat exposure tested negative for systemic Bartonella henselae antibodies. One patient with a history of cat exposure refused testing. Clinical courses were self-limited, with complete return of vision without treatment in all but one eye, which developed a juxtafoveal scar and localized traction retinal detachment in an area of prior retinitis. CONCLUSIONS: Idiopathic acute multifocal retinitis should be considered in any otherwise healthy, young-to-middle-age adult with acute loss of vision in the presence of multifocal retinitis, particularly when accompanied by an antecedent flu-like illness. Patients with idiopathic acute multifocal retinitis usually have favorable clinical course.

Acute Disease↗
PubMed1997

Indocyanine green videoangiography after acute retinal pigment epithelial tears in age-related macular degeneration.

PURPOSE: To determine the features of combined fluorescein and indocyanine green videoangiography after acute retinal pigment epithelial tears associated with age-related macular degeneration. METHODS: We performed combined fluorescein and indocyanine green videoangiography in three eyes of three patients 2 days to 2 months after the development of tears of the retinal pigment epithelium. RESULTS: The area of exposed choroid in a retinal pigment epithelial tear shows intense hyperfluorescence in fluorescein videoangiography; in contrast, this area demonstrates near-normal choroidal fluorescence on an indocyanine green videoangiogram. The folded and retracted flap of retinal pigment epithelium in a retinal pigment epithelial tear discloses marked hypofluorescence on the fluorescein videoangiogram; in contrast, this flap of retinal pigment epithelium displays varying degrees of hyperfluorescence on the indocyanine green videoangiogram. CONCLUSIONS: The angiographic differences between fluorescein and indocyanine green result from the distinct biophysical properties of these two dyes as well as from the differential penetration of their fluorescence through such pigmented structures as retinal pigment epithelium. Compared with fluorescein videoangiography, indocyanine green videoangiography allows better visualization of choroidal neovascular membranes within the rolled-up and retracted flap of the retinal pigment epithelial tear.

Acute Disease↗
PubMed1997

Grid laser photocoagulation for macular edema in bilateral juxtafoveal telangiectasis.

OBJECTIVE: The purpose of the study is to report the efficacy of laser photocoagulation treatment for macular edema in bilateral juxtafoveal telangiectasis (BJT). DESIGN: The study design was a retrospective, clinical study. PARTICIPANTS: The authors observed 14 patients with BJT, studying the visual acuities and retinal changes of treated and untreated eyes. MAIN OUTCOME MEASURES: Visual acuity, presence of macular edema, and associated retinal findings were measured. RESULTS: Of 28 eyes, 10 (8 patients) received 15 laser photocoagulation treatments for macular edema. Neither treated nor untreated eyes had visual improvement of two or more lines. After treatment, five eyes (50%) had increased retinal vascular distortion develop, three (30%) had new draining retinal venules, five (50%) had intraretinal fibrovascular tissues, and four (40%) had retinal and preretinal hemorrhages develop. CONCLUSIONS: Grid laser photocoagulation therapy for macular edema in patients with BJT appears to neither improve nor stabilize long-term visual acuity. In addition, treatment is associated with retinal pigment epithelial changes, increased postoperative retinal vascular distortion, postoperative vascularized retinal scars, and postoperative retinal hemorrhages. These changes, however, do not appear to cause a further loss of vision.

Aged↗
PubMed1997

Outpatient postoperative fluid-gas exchange after early failed vitrectomy surgery for macular hole.

BACKGROUND: Vitrectomy surgery with fluid-gas exchange and prone positioning has been shown to close macular holes and improve vision. In those eyes that have failed surgery, repeat vitrectomy has been advocated. As an alternative, the authors performed an outpatient postoperative fluid-gas exchange on eyes when the macular hole failed to close after vitrectomy surgery. METHODS: The authors reviewed all cases of failed vitrectomy surgery for macular holes that underwent a postoperative fluid-gas exchange. Eyes were considered to have failed initial surgery if a rim of subretinal fluid surrounded an open full-thickness macular hole. RESULTS: Twenty-three consecutive eyes underwent outpatient fluid-gas exchange 1 week to 8 weeks after vitrectomy surgery. In 17 eyes (74%), fluid-gas exchange resulted in flattening and closure of the macular hole. In all 17 eyes, visual acuity improved 2 or more lines, with 8 (35%) of the 23 eyes achieving 20/50 or better visual acuity. CONCLUSIONS: Postoperative fluid-gas exchange may achieve successful closure of macular holes and improve vision in eyes that have failed surgery for full-thickness macular holes and should be considered as a cost-effective alternative to repeat vitrectomy.

Aged↗
PubMed1997

Circulating tumor necrosis factor alpha is elevated in male but not in female patients with type II diabetes mellitus.

The cytokine tumor necrosis factor alpha (TNF alpha) was proposed to mediate obesity related insulin resistance upon production in fat cells and to participate in tissue remodelling leading to vascular complications upon being released by macrophages. To assess its putative role in diabetes we determined plasma levels of TNF alpha in 105 adult humans. Male nondiabetic subjects had significantly lower TNF alpha levels than female controls (4.4 +/- 0.3, n = 17 vs. 6.6 +/- 1.0 pg/ml, n = 13; p = 0.049). Men with NIDDM had elevated TNF alpha (6.7 +/- 0.6 pg/ml, n = 34) compared to nondiabetic subjects (4.4 +/- 0.3 pg/ml, n = 17; p = 0.012). Such a difference was not apparent in women. Levels of TNF alpha were correlated with serum triglyceride levels in male controls (r2 = 0.64; p = 0.007) but not in NIDDM. Neither body mass index nor glycosylated hemoglobin correlated with TNF alpha in any of the groups. The presence of retinopathy (p = 0.046) but not of neuropathy or nephropathy or macroangiopathy was associated with significantly elevated plasma TNF alpha. We conclude that plasma levels of TNF alpha are sex-dependent and that increased TNF alpha occurs in male but not female NIDDM and may participate in the development of diabetic complications.

Aged↗
PubMed1997

Ring retinal pigment epithelial window defect of the macula in central serous chorioretinopathy.

PURPOSE: Central serous chorioretinopathy is usually a benign disorder, in which resolution of serous subretinal fluid and return to a visual acuity of 20/40 or better is the normal outcome. In unusual cases of central serous chorioretinopathy, chronic subretinal fluid can lead to permanent retinal pigment epithelial depigmentation. In this report, we describe a ring-like (bull's eye) pattern of retinal pigment epithelial atrophy associated with central serous chorioretinopathy. METHODS: We examined eight patients (nine eyes) with central serous chorioretinopathy in whom retinal pigment epithelial window defects encircling the fovea developed. RESULTS: The average duration of symptoms before recognition of a circular window defect was 6 years. Visual acuity at the time of documentation of the ring-like window defect was 20/40 or worse in seven of nine (77%) eyes. Although laser photocoagulation treatment was performed in six of the nine eyes, vision improved two or more lines in only one eye (17%). CONCLUSION: Chronic central serous chorioretinopathy can cause a ring-like (bull's eye) pattern of retinal pigment epithelial window defects encircling the fovea. This pattern of retinal pigment epithelial window defect when seen in patients with central serous chorioretinopathy may indicate that a patient has a more severe form of central serous chorioretinopathy.

Adult↗