Scanning tunneling microscopy of the enzymes of muscle glycogenolysis

Scanning tunneling microscopy (STM) has been used to examine the structures of the skeletal muscle enzymes phosphorylase and phosphorylase kinase. The interaction of these two proteins represents the last step in the process of signal transduction which results in muscle glycogen being converted into metabolic energy for use in muscle contraction. Phosphorylase b has a molecular weight of 97,000 and the dimer is seen by STM to have dimensions of 11 X 5.7 nm. Phosphorylase b has a tendency to form linear arrays of dimers on the graphite surface used as the support for STM imaging. Phosphorylase kinase is imaged as a butterfly-like object with lateral dimensions of 36 X 27 nm. The molecular thicknesses given by scanning tunneling microscopy for these two non-conducting molecules is significantly less than expected. The height measurement in STM is dependent not only on the surface topology of the object being imaged, but also on the electronic work function of the object compared to that of the graphite surface on which it lies. In addition to the individual proteins, a complex between phosphorylase and phosphorylase kinase has been observed by scanning tunneling microscopy.

Adequacy of disposable biopsy forceps for gastrointestinal endoscopy: a direct comparison with reusable forceps

Disposable plastic biopsy forceps were compared prospectively to reusable stainless steel forceps. Thirty consecutive patients underwent a total of 249 biopsies, 124 with the disposable forceps, and 125 with reusable forceps. Biopsy locations included the esophagus, stomach, small intestine, colon, and common bile duct. Specimens were compared microscopically to determine overall surface area, depth, adequacy, and diagnostic result. The disposable biopsy forceps yielded specimens which were 37% smaller when compared with the reusable forceps. In five of the comparisons, minor differences in histological findings were noted between the two groups of biopsy specimens, but these differences did not alter the pathological diagnosis. However, in three cases in which superficial specimens were obtained, an underlying carcinoma was missed with the disposable forceps. Our study documents the utility of disposable biopsy forceps for mucosal lesions. In addition, there were 11 mechanical failures in 38 biopsy attempts with the plastic biopsy forceps. These forceps appear to be limited in their capacity to obtain adequate specimens from firm tissue or when submucosal biopsy samples are required, and they will require refinements in design to duplicate specimen quality obtained by traditional reusable forceps. Disposable forceps are particularly suitable for biopsy of mucosal lesions in patients with possible communicable disease, and they should help to reduce cross-contamination in the gastroenterology laboratory.

[Clinical analysis of 418 patients with Wilson's disease in traditional Chinese medicine and Western medicine therapy]

From 1974 to 1988, 418 cases of Wilson's disease were treated with TCM-WM in our hospital. 147 cases were of Wilson's type; 149 cases were of pseudosclerosis type; 40 cases were of abdominal and hepatocerebral type; 21 cases were of choreoathetosis type and 21 cases of other types. After a course of treatment for 3 to 6 months, 103 patients showed marked improvement and 286 made some improvement, but no effect was found in 22 patients and 7 deaths were observed. The results were as follows: (1) The mortality in the severe and moderate groups were significantly higher than the mild (P less than 0.05) and the marked effective rate was less than the latter (P less than 0.01). (2) The marked effective rate was lower in abdominal and hepatocerebral type, and no significant difference was found in recovery rate between Wilson's type and pseudosclerosis type.

Radioimmunotherapy in the multimodality treatment of hepatocellular carcinoma with reference to second-look resection

Experimental study using nude mice human hepatocellular carcinoma (HCC) xenograft indicated that the combination treatment with iodine 131 (131I)-anti-human HCC isoferritin (131I-isoFtAb), cisplatin, and mixed bacterial vaccine (MBV) yielded better inhibition rate as compared with double combination or 131I-isoFtAb alone. Based on these findings, 25 patients with surgically proven nonresectable and pathologically proven HCC have been treated by radioimmunotherapy using 131I-isoFtAb intrahepatic arterial infusion as a part of multimodality treatment. Of the 25 patients, seven (28.0%) received second-look resection after marked shrinkage of tumor. The 1-year survival was 52.5% (12/23) and 2-year survival 27.7% (five of 18) in the entire series. Of the five patients with 2-year survival, four were in the second-look resection group. Patients with tumor less than or equal to 8 cm showed higher second-look resection rate (62.5% versus 11.8%) and 1-year survival (85.7% versus 37.5%) as compared with tumor greater than 8 cm. Mixed bacterial vaccine as adjuvant immunotherapy seemed effective to prolong survival. The 2-year survival was higher in patients with second-look resection as compared with those without (75.0% versus 14.3%). Thus, radioimmunotherapy using 131I-isoFtAb might be one of the modalities of choice, particularly in the conversion of nonresectable to resectable HCC in a well-designed multimodality treatment regimen.

Surgery of small hepatocellular carcinoma. Analysis of 144 cases

A long-term follow-up study of 144 cases with surgically and pathologically proved small hepatocellular carcinoma (less than or equal to 5 cm) from 1967 to 1987 is reported. One hundred eight cases (75.0%) were detected by alpha-fetoprotein serosurvey and/or ultrasonography mainly in a high-risk population; 129 cases (89.6%) coexisted with cirrhosis. Resection was done in 132 cases (91.7%) with three (2.3%) operative deaths; cryosurgery, laser vaporization, and hepatic arterial chemotherapy were used in the rest. Limited resection was done in 67.4% of resections. Reresection of subclinical recurrence or solitary pulmonary metastasis was done in 21 cases. The 5-year and 10-year survival rates were 67.9% and 53.4% in the resection group but zero in the nonresection group. Survival was correlated negatively with tumor size, 5-year survival after resection was 84.6% in tumors less than or equal to 2 cm but 59.5% in tumors of 4.1 to 5 cm. The increase of resectability and reresection resulted in marked improved of 5-year survival from 43.5% in 1973 to 1977 to 63.3% in 1978 to 1982 in the entire series. No significant difference was found between survival of limited resection and lobectomy. Resection may be the modality of choice for treatment of small hepatocellular carcinomas with compensated liver function. Limited resection instead of lobectomy was the key to increased resectability and decreased operative mortality in cirrhotic livers. Reresection of subclinical recurrence was important to prolong survival further.

Surgery of small hepatocellular carcinoma. Analysis of 144 cases

A long-term follow-up study of 144 cases with surgically and pathologically proved small hepatocellular carcinoma (less than or equal to 5 cm) from 1967 to 1987 is reported. One hundred eight cases (75.0%) were detected by alpha-fetoprotein serosurvey and/or ultrasonography mainly in a high-risk population; 129 cases (89.6%) coexisted with cirrhosis. Resection was done in 132 cases (91.7%) with three (2.3%) operative deaths; cryosurgery, laser vaporization, and hepatic arterial chemotherapy were used in the rest. Limited resection was done in 67.4% of resections. Reresection of subclinical recurrence or solitary pulmonary metastasis was done in 21 cases. The 5-year and 10-year survival rates were 67.9% and 53.4% in the resection group but zero in the nonresection group. Survival was correlated negatively with tumor size, 5-year survival after resection was 84.6% in tumors less than or equal to 2 cm but 59.5% in tumors of 4.1 to 5 cm. The increase of resectability and reresection resulted in marked improved of 5-year survival from 43.5% in 1973 to 1977 to 63.3% in 1978 to 1982 in the entire series. No significant difference was found between survival of limited resection and lobectomy. Resection may be the modality of choice for treatment of small hepatocellular carcinomas with compensated liver function. Limited resection instead of lobectomy was the key to increased resectability and decreased operative mortality in cirrhotic livers. Reresection of subclinical recurrence was important to prolong survival further.

Direct observation of phosphorylase kinase and phosphorylase b by scanning tunneling microscopy

The molecular structures of phosphorylase b and phosphorylase kinase have been visualized by scanning tunneling microscopy (STM). STM is a near field technique that can resolve structures at the nanometer level and thus can image individual molecules. Phosphorylase b can be seen in dimeric and tetrameric forms as well as linear and globular aggregates. The linear arrays consist of side by side dimers with the long axis of the dimer perpendicular to the aggregated chain. Individual molecules of phosphorylase kinase appear to be planar, bilobate structures with a 2-fold axis of symmetry and a central depression.

Herpesviridae in the coronary arteries and aorta of young trauma victims

The presence of herpes simplex virus (HSV) and cytomegalovirus (CMV) nucleic acid and/or antigen was demonstrated in the coronary arteries and thoracic aortas of young trauma victims by the in situ DNA hybridization and ABC immunoperoxidase methods, respectively. Epstein-Barr virus (EBV) nucleic acid and capsid antigen were not detected in the arteries sampled in this study. Of 8 subjects in which virus was detected in the coronary arteries, 6 were positive for HSV and 2 for CMV; of 7 cases positive in the thoracic aorta, 5 were identified as HSV and 2 as CMV. Viral DNA and/or antigen were found in occasional cells in the intact luminal surface and in focal clusters of spindle-shaped or "foamy" cells in the intimal layer. The histologic findings indicate that HSV and CMV are associated with areas showing early or advanced atheromatous changes in the coronary arteries and with lesion-free as well as lesion areas in the thoracic aorta. The virologic findings support the concept that herpes-viruses may potentially play a direct or indirect role in the pathogenesis of human atherosclerosis.

[Misdiagnosis of malignant lymphoma--report of 45 patients]

A series of 50 patients with malignant lymphoma, proven by biopsy, was retrospectively studied. 39 were non-Hodgkin's lymphoma and 11 Hodgkin's disease. 45 (90%) had been misdiagnosed because of lack of initial specific symptoms. It is suggested that for patients with a painless progressively enlarging superficial lymph node without adhering to its surrounding tissues and irresponsive to general management, having irregular fever, bloody stool, abdominal pain or mass, complication of partial intestinal obstruction, sharp vigilance be kept for the possibility of malignant lymphoma.

Hypoxia-induced inhibition of converting enzyme activity: role in vascular regulation

Systemic and pulmonary vascular reactivity to graded doses of angiotensin I (ANG I), angiotensin II (ANG II), and, as a control, phenylephrine were examined in 14- or 28-day hypoxia-exposed and air control rats. Hypoxic rats exhibited pulmonary hypertension that was reversible on return to room air, but systemic arterial pressure was not altered by hypoxia. Systemic pressor responses to ANG I and ANG II were significantly less in the hypoxic rats than in the control rats at 14 and 28 days but returned to control levels in hypoxic animals that were then returned to room air, demonstrating reversibility of the hypoxia-induced changes in vascular reactivity. Pulmonary pressor responses to ANG I were significantly less at 14 days, whereas responses to ANG II were significantly greater at 28 days, in hypoxic rats than in controls. There were no significant differences in systemic and pulmonary pressor responses to phenylephrine between the hypoxic and air control animals. The altered systemic and pulmonary pressor responsiveness to ANG I and ANG II in hypoxic rats is probably related to mechanisms specific to the renin-angiotensin system, such as inhibition of intrapulmonary angiotensin-converting enzyme activity and down regulation of ANG II receptors in the systemic circulation. Further study is needed to elucidate these mechanisms.

Approximate formulas for the microbending loss in single-mode fibers

Some approximate formulas for calculating the microbending loss for single-mode fibers are given. The formulas are rather simple, yield good approximate values, and hence can be used to evaluate the microbending loss in fiber design.

Repair of upper ureteric obstruction with Boari flap and psoas hitch

A case of iatrogenic traumatic obstruction to both upper and lower ureters resulting in severe hydronephrosis is reported. Continuity and good functional result was achieved with a Boari flap and psoas hitch to the renal pelvis.

Serologic survey of human hydatid disease in high risk populations from central Tunisia. Preliminary results

The annual surgical incidence rate of hydatid disease in central Tunisia varies from 11.1 to 30.1 per 100,000 population depending on the district. In order to obtain more comprehensive data, we conducted a serologic survey in the district with the highest rate, using hemagglutination-inhibition to test 480 workers from a state farm and 190 inhabitants of villages in the neighborhood. The overall prevalence rate was 1.3% (9/670). Echotomography revealed liver cysts in all cases and the diagnosis was confirmed in the eight subjects who underwent surgery. If these preliminary results are confirmed by further surveys, mass screening might be considered in high risk districts.

Gastrointestinal tract complications of diabetes mellitus. Pathophysiology and management

Diabetes mellitus can affect every organ system, including large and small blood vessels, eyes, nerves, kidneys, and the gastrointestinal (GI) tract. We reviewed recent knowledge concerning the impact of diabetes on the gut. While the incidence of GI tract complications is usually considered relatively low, functional alterations have been demonstrated at every level in the gut and account for considerable morbidity in the diabetic population.

The nucleotide sequence of a new human repetitive DNA consists of eight tandem repeats of 66 base pairs

Three cloned human DNA fragments obtained from a fibroblast genomic DNA were sequenced and identified as containing members of the well-known 300-bp Alu family of interspersed, middle-repetitive DNA sequences. One of these cloned DNA fragments, p16, also contains members of a new repetitive DNA family, which repeats several thousand times in the human genome. Each member of the new 528-bp family consists of eight tandem repeats of a 66-bp sequence. An AluI recognition site is present at the same location in each repeat, and a 25-bp sequence occurs twice (as a tandem repeat) in each of the eight repeats. There is no sequence homology between the new 528-bp family and the 300-bp Alu family, and the new family lacks the flanking 7- to 20-bp direct repeats as well as the dAMP-rich sequences characteristic of the 300-bp Alu family. Construction of a putative evolutionary tree indicates that six duplication events are needed to give rise to the eight tandemly repeated 66-bp units in the new 528-bp family.

Interferon activity produced by interferon messenger RNA in Tilapiamosaiabica peters oocytes

The activities of interferon mRNA from various types of mouse cells have been studied using Tilapiamosaiabica peters oocytes (TPO) as the translation system. The translation activity of interferon mRNA in TPO was also compared with that in Xenopus laevis oocytes (XLO). The results obtained showed similar translation efficiency in both systems. The highest translation efficiency was observed when T. peters oocytes, microinjected with mRNA, were cultivated in Eagle's medium containing 0.01% HEPES and 0.5% NaHCO3 (pH 7.5) at 25 degrees C. pppA2' P5' A2' P5' A in concentration of 500 nM did not affect the translation of interferon mRNA in oocytes, but inhibition was demonstrated at 1 microM. A linear relationship was found between the amount of interferon mRNA injected and the antiviral activity of the translation products, suggesting that the amount of interferon mRNA can be determined by assaying the interferon activity of its translation product.

Peak homogeneity determination for the validation of high-performance liquid chromatographic assay methods

To validate high-performance liquid chromatographic assay procedures with regard to specificity, methods were developed to determine the homogeneity of the chromatographic peaks. These methods employed a rapid-scanning UV-visible spectrophotometer to monitor the chromatographic effluent. The absorption data were processed to nullify the signal due to the drug substances specifically, while allowing the detection of coincident impurities. Results from three model systems indicated the ability of these methods to detect as little as 0.1% of a coincident impurity.