Angioscopy for intraoperative management of thromboembolectomy

Our experience with angioscopy suggests that direct visualization of the arterial lumen during thromboembolectomy procedures would provide a more reliable method of assessing luminal morphologic characteristics than angiography alone. We inspected 32 grafts (seven aortobifemoral, 18 infrainguinal bypass, and seven dialysis access fistula grafts) in 32 patients. Thirty-one patients had thrombotic events and one patient had an acute embolus. Angioscopy following standard catheter thrombectomy revealed significant amounts of retained thrombus or neointima in all thrombectomies. Angioscopic information from 18 patients with an infrainguinal bypass graft led to graft revision in six cases and placement of a new graft in 10 cases. One graft limb was replaced in seven aortobifemoral grafts, and multiple repeated thrombectomies were employed to extract debris in the remaining six cases. Repeated graft thrombectomy was also beneficial in dialysis access fistulas. Angioscopy allowed us to omit the completion angiogram and led to an improved technical result. We conclude that angioscopy is useful during thromboembolectomy procedures.

The development of USP dissolution and drug release standards

Dissolution tests have been in use in the pharmaceutical industry for over 20 years, and they are official in The United States Pharmacopeia since the early 1960s. The dissolution test, reviewed primarily as a quality control tool, replaced the use of disintegration tests which had been official in The United States Pharmacopeia since 1950. Refinements in the dissolution test equipment and methodology have occurred over the years in order to enhance its relevance. The Subcommittees of the USP Committee of Revision dealing with these issues have developed and refined compendial dissolution standards and policies for conventional solid-oral dosage forms and modified-release dosage forms.

Human serum megakaryocyte colony-stimulating activity appears to be distinct from interleukin-3, granulocyte-macrophage colony-stimulating factor, and lymphocyte-conditioned medium

Sera from patients with bone marrow megakaryocyte aplasia are a rich source of megakaryocyte colony-stimulating activity (Meg-CSA). Other biologic materials exhibiting Meg-CSA include phytohemagglutinin-stimulated human lymphocyte-conditioned medium (PHA-LCM), recombinant interleukin-3 (IL-3), and recombinant granulocyte macrophage colony-stimulating factor (GM-CSF). Neutralizing antisera to both recombinant IL-3 and GM-CSF were used to evaluate the relationship among these sources of Meg-CSA. Varying dilutions of IL-3 and GM-CSF antisera were tested in plasma clot cultures of normal human peripheral blood megakaryocyte progenitors optimally stimulated by either IL-3 (1 U/mL), GM-CSF (1 U/mL), PHA-LCM (2.5% to 5% vol/vol), or aplastic human serum (10% vol/vol). IL-3 antiserum at dilutions up to 1/2,000 totally abrogated megakaryocyte colony growth stimulated by IL-3. A 1/500 dilution of GM-CSF antiserum completely eliminated GM-CSF-induced megakaryocyte colony development. A combination of anti-IL-3 and anti-GM-CSF, each at a 1/500 dilution, inhibited all megakaryocyte colony growth stimulated by optimal concentrations of IL-3 and GM-CSF together. There was no neutralizing crossreactivity between the IL-3 and GM-CSF antisera. At maximally neutralizing concentrations, IL-3 antiserum inhibited 66% of the megakaryocyte colony growth stimulated by PHA-LCM. Residual megakaryocyte colony growth was eliminated by the addition of a 1/500 dilution of anti-GM-CSF.(ABSTRACT TRUNCATED AT 250 WORDS)

The presence of a porphyropsin-based visual pigment in the juvenile lemon shark (Negaprion brevirostris)

The visual pigment from the juvenile lemon shark has been extracted and is a homogeneous vitamin A2-based porphyropsin with maximum absorption at 522 nm. This is the first report of a porphyropsin visual pigment extracted from the retina of an elasmobranch. In contrast, the visual pigment from the adult lemon shark yields a homogeneous vitamin A1-based rhodopsin with maximum absorption at 501 nm. We conclude that the porphyropsin of the juvenile lemon shark changes over to a rhodopsin as the animal matures.

The risk of carotid endarterectomy for the asymptomatic patient: an argument for prophylactic operation

We reviewed the records of 291 asymptomatic patients who underwent 377 carotid endarterectomy operations. The study excludes endarterectomies performed simultaneously with other operations that influence morbidity as well as endarterectomies on patients with symptoms caused by contralateral carotid stenosis. Postoperatively, nine patients had a stroke but two of the nine recovered completely after reoperation. Seven patients (2% of operations) were discharged with a neurologic deficit. One patient died of a myocardial infarction. Combined strokes with residual deficit and deaths totaled eight patients (2.2% of operations). During the time of the study the indication for operation changed from greater than 60% stenosis of the carotid artery to greater than 80% stenosis. This paper argues that, based on information currently available, a surgical morbidity rate of less than 3% justifies prophylactic endarterectomy. Surgeons must audit their results to demonstrate they can perform the operation with low risk to the patient.

Comparison of contrast arteriography to arterial mapping with color-flow duplex imaging in the lower extremities

Color flow duplex scanning was used to "map" the iliofemoral and femoral popliteal segments in 61 patients (84 extremities) undergoing evaluation for excimer laser angioplasty. Eight locations, iliac, common femoral, profunda femoris, proximal and distal superficial femoral artery, proximal and distal popliteal, and tibioperoneal trunk were scored as normal versus abnormal, greater than 50% stenosis, or occluded, and occlusions were measured in centimeters. Specificity, sensitivity, and accuracy were calculated with the arteriogram as the gold standard (83% and 96%, respectively, for normal vs abnormal, 87% and 99% for 50% stenosis, and 81% and 99% for occlusions). Color flow accurately identified the presence and extent of occlusions in 48 of 51 extremities (94%) when compared to arteriography plus operative findings, since arteriography alone tended to overestimate occlusion length. It is concluded that color flow Doppler alone may be used to screen patients with peripheral vascular disease to assess candidacy for endovascular procedures without antecedent arteriography, and that arteriography alone would exclude some patients from consideration by falsely overestimating occlusion lengths.

Rectovaginal fistula in Crohn's disease

Rectovaginal fistulas in the setting of Crohn's disease present a difficult management dilemma. Some patients with this problem require proctocolectomy, yet other patients with minimal symptoms never require an operation for treatment of the rectovaginal fistula. For a small percentage of patients, local surgical repair of the fistula may be warranted. Since 1980, this study has attempted local repair in seven patients with symptomatic rectovaginal fistulas from Crohn's disease. Five patients underwent staged repair of the fistula. Closure of the colostomy was eventually possible in three of these patients. Two of the three patients have had no evidence of recurrence at followup in excess of two years. The third patient required an ileostomy for intestinal disease and had no recurrence of the fistula. Two patients underwent primary repair of the rectovaginal fistula without fecal diversion; in one of these patients, the fistula recurred ten days after operation, necessitating a diverting ileostomy. The other patient remains cured 26 months after repair. The results of this review indicate that in the setting of quiescent rectal disease, an attempt to repair the fistula can be expected to have a reasonable chance of success. The presence of a rectovaginal fistula in a patient with Crohn's disease does not mandate removal of the rectum.

Monocular blindness after penetrating trauma to the carotid artery

Near-total or total blindness caused by chronic ocular ischemia is a well-recognized complication of severe atherosclerotic occlusive disease of the carotid artery (CA) but has not been previously reported in the English-language literature as a sequela of an occlusive CA injury. This report describes a patient who sustained a gunshot wound to the neck, which injured the ipsilateral internal CA, external CA, and vertebral artery. The location of the injuries precluded arterial repair. The patient was neurologically intact after operative exploration. Twenty months after the injury a marked loss of vision in the ipsilateral eye was detected. Chronic ocular ischemia was diagnosed from clinical findings and ophthalmoscopic examination results. Knowledge that chronic ocular ischemia and blindness can occur after an occlusive CA injury supports the use of primary arterial repair for all CA injuries. In those instances in which repair is not technically possible, frequent ophthalmoscopic examinations and testing of visual acuity should be used postoperatively to diagnose ocular ischemia; thus treatment to prevent the loss of sight can be carried out.

Liver abscess. The need for complete gastrointestinal evaluation

The cause of liver abscess is frequently obscure at initial presentation. We reviewed the medical records of 20 patients with pyogenic liver abscess over a 6-year period from 1981 to 1987. Liver abscess was suspected in only 3 patients on admission; the most common initial diagnosis was fever of unknown origin. Subsequently, the origin of the abscess was found to be intestinal in 7 patients, pancreatobiliary in 11 patients, and cryptogenic in 2 patients. Eleven patients underwent percutaneous transhepatic drainage of the abscess as the initial treatment, while open operation was the initial treatment in 9 patients. Percutaneous transhepatic drainage was ultimately successful in only 4 patients (36%). In the absence of an obvious pathologic condition of the biliary tract, all patients should undergo full gastrointestinal evaluation.

Complications with the variable spinal plating system

From January 1986 to June of 1987, 40 patients underwent transpedicle fixation and fusion using the variable spinal plate system. Nineteen patients had undergone surgery at the same level or levels, and 21 patients had undergone no previous surgery. Diagnostic categories include spondylolisthesis, thoracolumbar and lumbar fractures, internal disc derangement, spinal stenosis, pseudarthrosis, mechanical instability, and fracture mal-union. Minimum follow-up has been 14 months, with the average being 20 months. Overall results showed 13 excellent, 12 good, seven fair, and eight poor. The overall complication rate was 45%. In those patients undergoing no previous surgery, it was 29%, but with those patients having previous surgery, it was 63%. Most of these complications were minor in nature and resolved before discharge. Implant failure occurred in seven patients, and consisted of screw breakage. Design modifications currently available should help minimize this complication. Although this method of internal fixation and fusion is technically demanding and has a high complication rate, it is considered to be indicated in lumbar fractures, revision of pseudarthrosis, spondylolisthesis with or without reduction, and failed surgery with marked instability.

Prevalence and significance of acquired immunodeficiency syndrome-related retinal microvasculopathy

We performed ophthalmologic examinations on 127 subjects with or at risk for human immunodeficiency virus (HIV) infection over a one-year period to determine the prevalence and significance of retinal cotton-wool spots and hemorrhages (AIDS-related retinal microvasculopathy). Of 26 asymptomatic homosexual men, of whom 13 were HIV seronegative and 13 were HIV seropositive, none manifested this retinopathy. Three of 34 patients (9%) with AIDS-related complex and 29 of 67 patients (43%) with AIDS manifested retinopathy on the initial examination. This difference in the prevalence of retinopathy between groups was statistically significant (P less than .05). Patients with AIDS demonstrated 7.2 times greater odds of manifesting retinopathy than patients with AIDS-related complex (P less than .05). Within the group of patients with AIDS, the T helper (CD4) to suppressor (CD8) cell ratio was significantly associated with retinopathy at the initial ocular examination. The CD4:CD8 ratio of the total group of AIDS and AIDS-related complex patients with retinopathy was significantly lower than that of patients without retinopathy (P less than .05). There was no significant association between retinopathy and any specific past or concurrent opportunistic infection or neoplasm. The presence of retinopathy was not associated with symptoms in any patient. The lesions of AIDS-related retinal microvasculopathy may be an important finding in the evaluation of patients suspected to have HIV-related disease.

High-pressure liquid chromatographic analysis of eflornithine in serum

Eflornithine [2-(difluoromethyl)-DL-ornithine monohydrochloride, monohydrate; DFMO] is an ornithine decarboxylase inhibitor used to treat Pneumocystis carinii pneumonia (PCP) in AIDS patients unresponsive or intolerant to conventional drug therapy. A reversed-phase HPLC method utilizing precolumn dansylation is described which permits the analysis of DFMO in serum of AIDS patients in support of pharmacokinetic studies. Norvaline (2-amino valeric acid) was added as the internal standard and the sample was extracted with three portions of ice-cold 80% ethanol. The supernatants were evaporated in a vacuum oven at 50 degrees C, and the residue was dissolved in base and derivatized at 25 degrees C for 4 h in the dark using dansyl chloride in acetone. Dilute base was then added and 25 to 50 microL was injected into the HPLC. Chromatography was performed on a C-8, 15-cm column with a linear gradient from a 95:5 solution of 10 mM pH 4 acetate buffer and THF, to a 90:10 solution of acetonitrile and THF over a period of 28 min. Detection was by UV at 330 nm, and DFMO and norvaline eluted at 14.7 and 17.7 min, respectively. The method was linear over a range of 5 to 950 micrograms/mL, and replicate analyses of a 25-micrograms/mL control specimen produced a between-run coefficient of variation of 6%. No interferences were encountered in a variety of patient and normal serum blanks.

Defective megakaryocytopoiesis in the syndrome of thrombocytopenia with absent radii

The syndrome of thrombocytopenia with absent radii (TAR) is a hereditary condition whose pathogenesis is poorly understood. In this investigation we evaluated a female infant with TAR and her parents using in vitro haematopoietic colony forming assays and an antiserum against platelet membrane glycoproteins (PGP) to label smears of her bone marrow. Megakaryocyte colony growth in vitro was virtually absent in optimally stimulated cultures of the patient's bone marrow progenitors. In contrast, erythroid and myeloid colony growth from the TAR infant's marrow cells was preserved. Staining of the patient's bone marrow smears with PGP antiserum detected no immature, small megakaryocyte precursors. A high level of megakaryocyte colony stimulating activity was detected in serum from the TAR infant, activity comparable to that present in sera from adults with aplastic anaemia. The elevated serum activity decreased by 6 months of age at which time partial platelet recovery had occurred. Evaluation of both peripheral blood haematopoietic progenitor cells and sera from the TAR infant's parents demonstrated no significant abnormalities. We conclude that the principle haematopoietic defect in this patient with TAR syndrome is the absence or arrested development of the committed megakaryocyte progenitor cell. Humoral regulation of megakaryocytopoiesis appears intact and is responsive to the degree of megakaryocytic hypoplasia.

Recombinant gibbon interleukin-3 stimulates megakaryocyte colony growth in vitro from human peripheral blood progenitor cells

Gibbon interleukin-3 (rIL-3) has recently been cloned and found to have a high degree of homology with the human IL-3 molecule. In this investigation, we evaluated the effects of gibbon rIL-3 on normal human peripheral blood megakaryocyte progenitor cell growth in vitro. Gibbon rIL-3 exhibited substantial megakaryocyte colony stimulatory activity (Meg-CSA), supporting peak colony numbers at a concentration of 1 U/ml. Megakaryocyte colony growth induced by rIL-3 reached 58% of the maximum achieved with the active, Meg-CSA-containing protein fraction of aplastic canine serum. Increasing gibbon rIL-3 concentrations also stimulated a 4-5-fold increase in megakaryocyte colony size and resulted in a decrease in geometric mean megakaryocyte ploidy. Ploidy values fell from 8.5N +/- 1.4 (+/- SEM) at an rIL-3 concentration of 0.1 U/ml to a minimum of 2.9N +/- 0.3 at 10 U/ml. In the presence of rIL-3 at 1.0 U/ml, megakaryocyte colony growth was linear with cell plating density and the regression line passed approximately through the origin. The effects of rIL-3 on megakaryocyte colony growth were independent of the presence of T-lymphocytes in the cultures. Cross-species evaluation of murine and gibbon IL-3 indicated that its bioactivity is species restricted. Murine IL-3 did not support colony growth from human megakaryocyte progenitors and gibbon rIL-3 showed no activity in stimulating acetylcholinesterase production by murine bone marrow cells. Gibbon rIL-3 is a potent stimulator of the early events of human megakaryocyte progenitor cell development promoting predominantly mitosis and early megakaryocytic differentiation.

Anastomotic false aneurysms of the abdominal aorta and the iliac arteries

Anastomotic false aneurysm (AFA) of the aorta or iliac artery is a potentially lethal complication of prosthetic grafts. To study this complication, the records of 18 patients with 22 noninfected AFAs (15 aortic and seven iliac) were reviewed. Patients with an intact AFA had a pulsatile abdominal mass, abdominal pain, an occluded graft, peripheral emboli, or a femoral anastomotic false aneurysm. All patients with a ruptured AFA were in shock, but 67% (four of six) had symptoms before hemorrhage. For diagnosis, single-plane angiography was 69% accurate (11 of 16), computed tomography was 100% accurate (six of six), and ultrasound was used once and suggested an AFA. Three patients with an AFA less than 5 cm diameter were initially observed; however, all three aneurysms rapidly enlarged and one ruptured. The operative mortality rate was 8% (1 of 12) for patients with an intact aneurysm and 67% (four of six) for patients with a ruptured aneurysm. Treatment was resection of the AFA and replacement with a new graft. Retroperitoneal AFAs often appear years after the initial operation, and life-long follow-up is required for patients with an aortic or iliac graft. All retroperitoneal AFAs should be resected since the outcome of patients with a ruptured AFA is poor.

The action of gamma-aminobutyric acid on the horizontal cells of the skate retina

The effects of gamma-aminobutyric acid (GABA) were studied in the superfused retina of the skate. Intracellular recordings were made from horizontal cells. After application of 500 microM GABA there was a depolarization of the membrane potential, a decrease in the light-evoked amplitude of the response and an increase in the duration of the waveform.

Growth characteristics of circulating hematopoietic progenitor cells from patients with essential thrombocythemia

Peripheral blood mononuclear cells from five patients with essential thrombocythemia (ET) were cultured in vitro to evaluate restricted megakaryocytic (CFU-Meg), myeloid (CFU-GM), and erythroid (BFU-E) progenitor cell development. Varying concentrations of aplastic canine serum served as the source of megakaryocyte colony-stimulating activity, and cultured megakaryocyte ploidy distributions were determined by Feulgen staining and microfluorometry. Megakaryocyte colony growth was strikingly abnormal in all five patients evaluated. Four of the 5 had a marked expansion in the concentration of circulating CFU-Meg and 3 of 4 manifested abnormalities in cultured megakaryocyte colony size (2 unusually large and 1 small). Unstimulated megakaryocyte colony growth was substantially increased in three patients. However, the fraction of megakaryocyte progenitors in cell cycle was near or below normal in all instances. Endomitotic megakaryocyte development was disordered in each of the four ET patients in whom it was evaluable. In normal subjects, mean megakaryocyte ploidy values vary biphasically with aplastic canine serum concentration and peak at 13.2 N following 12 to 15 days of culture. In contrast, day 12 mean ploidy values in cultures from the ET patients remained low at all aplastic canine serum concentrations and reached a maximum averaging only 8.4 N. Three patients were evaluated serially at extended culture durations of up to 21 days. The cultured megakaryocyte ploidy was unchanged during this interval for two of the patients. For the third patient, ploidy increased steadily, reaching abnormally high ploidy values by day 21. Progenitor cell expansion was limited to the megakaryocyte line in three patients. However, two patients had substantial increases in CFU-GM, one of whom also had a marked increase in BFU-E. There was no significant unstimulated colony growth by either CFU-GM or BFU-E. These data indicate that ET is usually characterized by an expansion in the concentration of circulating CFU-Meg in vivo which manifest both disordered replication and endoreduplication in vitro.

Intraoperative colonoscopy

From 1973 to 1985, we performed intraoperative colonoscopy on 68 patients with indications as follows: location of a previous polypectomy site (44%), inability to complete colonoscopy preoperatively (24%), locating nonpalpable polyps (13%), to define the source of lower gastrointestinal bleeding (4%), and to perform polypectomy (3%). Endoscopic evaluation influenced the outcome in 93% of the patients. There were two complications, both splenic capsular tears. Despite our increased ability to resolve several of the earlier indications for intraoperative colonoscopy by examination prior to celiotomy, there remains a significant role for intraoperative colonoscopy.

Evaluation of bone marrow megakaryocyte ploidy distributions in persons with normal and abnormal platelet counts

Using bone marrow smears of the type prepared routinely in clinical practice, we determined megakaryocyte ploidy distributions in five normal persons, eight patients with both normal platelet counts and normal bone marrow morphology, and 18 patients with quantitative platelet disorders. To include 2N and 4N megakaryocytes in the ploidy distribution histograms, all megakaryocytes were identified by serial immunologic labelling with rabbit antiserum to human platelet glycoproteins and rhodamine-conjugated goat anti-rabbit igG. Cell nuclei were concurrently Feulgen stained with bis-aminophenyl-oxdiazole, and the nuclear fluorescent signals were quantified photometrically. A modal megakaryocyte ploidy value of 32N was seen in 10 of the 13 persons with normal platelet counts, and geometric mean megakaryocyte ploidy values averaged 24.9N +/- 7.0N (arithmetic mean +/- SD). In these normal control individuals, 2N and 4N megakaryocytes accounted for 11.1% of all megakaryocytes, and 2.6% of the megakaryocytes were 128N. Shifts to a higher mean ploidy were observed in five of seven patients with idiopathic thrombocytopenic purpura, resulting from increased percentages of 64N and 128N megakaryocytes at the expense of 4N, 8N, and 16N cells. Shifts to lower ploidy were demonstrated in two patients with acute myelogenous leukemia and one patient each with thrombotic thrombocytopenic purpura and isoimmune thrombocytopenia. Four of five patients with essential thrombocythemia had strikingly abnormal megakaryocyte ploidy histograms characterized by the presence of unusually high ploidy 256N and 512N megakaryocytes. These 256N and 512N cells were virtually unique to the patients with essential thrombocythemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Examination of the correlation of serum metoclopramide levels with antiemetic efficacy in patients receiving cisplatin

The existence of a threshold serum metoclopramide level above which total protection from cisplatin-induced vomiting is more likely to occur has been proposed. We monitored serum metoclopramide levels prior to the third metoclopramide dose in the first cisplatin treatment cycle in patients receiving metoclopramide 2 mg/kg x 4 as part of a randomized double-blind cross-over study comparing single-agent metoclopramide with combination metoclopramide and dexamethasone. Serum samples from 35 patients (17 receiving single-agent metoclopramide and 18 receiving the combination) were analyzed using reverse-phase high-pressure liquid chromatography (HPLC). A wide variation in metoclopramide levels was observed (range 273-3380 ng/ml). Serum levels obtained from the same patient on multiple treatment cycles were well correlated, and the addition of dexamethasone did not alter serum metoclopramide levels. No threshold level could be identified for the two groups (single-agent or combination antiemetic therapy) considered individually or considered together. However, significantly more vomiting episodes and a lower incidence of total protection were noted in patients with metoclopramide levels above 1469 ng/ml receiving metoclopramide alone. This effect was nullified in the combination antiemetic group. Our data do not support a directly proportional relationship between serum metoclopramide level and antiemetic protection. However, a non-linear relationship with a possible agonist/antagonist effect is suggested.