Prenatal administration of methadone in the rat: acoustic startle amplitude and the rest-activity cycle at 30 days of age

Two doses of methadone were administered by osmotic minipump from Day 8 of gestation through parturition, a dosing technique previously shown to produce physical dependence in the dams. A pair-fed control group received sterile water via minipump and was allowed to eat and drink only the amount consumed by the high-dose group on the same gestation days. A nontreated control group was left undisturbed during pregnancy. All treated and control litters were fostered at birth to untreated dams. The effects of methadone on maternal and offspring toxicity replicated our previous findings. At 29-31 days of age each treated and control animal was tested either for changes in acoustic startle amplitude or the rest-activity cycle. Methadone treated offspring were no different from the controls on either measure. These findings support the hypothesis derived from our earlier research that prenatal exposure to methadone produces a prolonged but transitory opioid abstinence. This is evidenced by increased startle amplitude and a disturbed rest-activity cycle that peaks at approximately 3 weeks of age. We demonstrate that these effects are no longer evident at 4 weeks of age. Together, these findings define a state of hyperexcitability in the young rat that resolves by 1 month of age. This transitory state parallels clinical descriptions of human infants undergoing opiate abstinence.

Didemnin B in metastatic malignant melanoma: a phase II trial of the Southwest Oncology Group

Didemnin B is a cyclic peptide isolated from the marine tunicate Trididemnin cyanophorum. It is a known potent inhibitor of RNA, DNA and protein synthesis, with activity against the murine B16 melanoma. Fourteen patients with disseminated malignant melanoma were evaluated in a Southwest Oncology Group phase II trial of didemnin B at 4.2 mg/m2 by 30 min i.v. infusion every 28 days (SWOG-8754). Only patients with no prior chemotherapy were eligible; prior radiation therapy, surgery and at most one prior biologic regimen were allowed. Patients with brain metastasis were eligible only if the disease in the brain had been treated and controlled. All patients had to have normal renal and hepatic function and adequate granulocyte and platelet counts, a performance status of 0-2, and bidimensionally measurable disease. Fourteen patients were entered on the study; five received one and nine received two courses of didemnin B. No responses were noted among the 11 patients evaluable for response. Five patients developed unusual but reversible hypersensitivity reactions during the second course of therapy. Other toxicity in this trial was nausea and vomiting and diarrhea, none of severity greater than grade 3. Given the lack of antitumor efficacy and the unusual toxicity, further evaluation of didemnin B in this dose and schedule in malignant melanoma is not warranted.

Phase II trial of amonafide in patients with advanced metastatic or recurrent endometrial adenocarcinoma. A Southwest Oncology Group study

Amonafide, a benzisoquinoline-1,3-dione was administered to 38 patients with recurrent or metastatic, bidimensionally measurable endometrial cancer. There were 34 patients with no prior cytotoxic chemotherapy, performance status of 0-2, and normal bone marrow, renal, and hepatic function were eligible for response and toxicity evaluation. Amonafide, 300 mg/m2, was administered intravenously over 1 hour daily for 5 consecutive days. Courses were repeated every 21 days. The major grade 3 or 4 toxicities were hematologic with granulocytopenia in 18 patients (53%), thrombocytopenia in 6 patients (18%), and anemia in 8 patients (24%). Infectious complications occurred in 3 patients (9%). Other side effects included cardiac dysrhythmias, hypotension, pain and phlebitis at the site of injection, nausea, vomiting, and flu-like symptoms. The overall objective response rate was 6% (95% confidence interval of 1-20%); 2 patients had a complete response (6%), 9 patients had stable disease (26%) and 21 patients had progressive disease (62%). Two patients had insufficient follow-up for response determination and are assumed to be nonresponders. The median survival of the eligible patients was 8 months. With the toxicity observed and the low response rate, amonafide at this dose and schedule has no efficacy in the treatment of endometrial cancer.

Factors influencing the duration of work-related disability: a population-based study of Washington State workers' compensation

OBJECTIVES

The purpose of this study was to examine factors predictive of duration of work-related disability.

METHODS

Multivariate survival analysis techniques were used to conduct a population-based, retrospective cohort study on a random sample of 28,473 workers' compensation claims from Washington State filed for injuries occurring in 1987 to 1989. The principal outcome measure was length of time for which compensation for lost wages was paid, used as a surrogate for duration of temporary total disability.

RESULTS

The findings suggest that, even after adjusting for severity of injury, older age, female gender, and a diagnosis of carpal tunnel syndrome or back/neck sprain significantly predict longer duration of disability. Other predictors that were stable and significant, but involved lower magnitudes of effect included divorced marital status, firm size of fewer than 50 employees, higher country unemployment rates, and construction and agricultural work.

CONCLUSIONS

Greater disability prevention efforts targeting these higher risk subgroups could have significant economic and public health effects. The greatest impact may be on claimants who remain disabled at 6 months after an injury that did not require hospitalization.

Gamma-melanocyte stimulating hormone (gamma-MSH)-like immunoreactivity is present in certain normal human keratinocytes

Using the indirect immunohistochemical approach, the occurrence of gamma-melanocyte stimulating hormone (gamma-MSH)-like immunoreactivity in human normal keratinocytes is described. The positive cells were observed in each layer of the epidermis (except stratum corneum) and often, at the level of the stratum spinosum, also around the orifices of cutaneous accessory organs, such as sweat glands and sebaceous glands/hair follicles. Combining these data with our previous investigations, the results support the possibility that locally produced gamma-MSH could be involved in cutaneous immune response, pigmentation and epithelial proliferation, as well as neuromodulation.

Selection designs for pilot studies based on survival

In cancer clinical trials new regimens are typically tested for antitumor activities in patients with advanced disease. The promising ones are then compared to the standard treatment in a randomized study, sometimes performed on patients with earlier-stage disease. When there are multiple promising regimens, it may not be possible to compare all of them to the control group because of the prohibitive sample size and study length requirements. We propose a design that uses the Cox regression model to select a best treatment based on survival before the randomized comparison. Sample sizes for an asymptotically correct selection probability of .90 are presented for Weibull survival distributions with parameters in a range we consider to be of practical interest. Simulations verify that the asymptotic approximations to the correct selection probabilities are quite satisfactory. Simulations also indicate that the procedure is reasonably robust to the proportional hazards assumption. In contrast to the two-stage screening design recommended by Schaid, Wieand, and Therneau (1990, Biometrika 77, 507-513), our design has the advantage of fitting naturally to a progression of cancer trials where the selection and comparison phases are carried out on different populations of patients. When the population of interest stays the same, our design can be more conservative on the average but offers the opportunity to base the comparative trial on the experience gained during the selection phase.

Appearance of heparin-binding EGF-like growth factor in wound fluid as a response to injury

Wound fluid was obtained from porcine partial-thickness excisional wounds and analyzed for heparin-binding growth factors. Two heparin-binding growth factor activities were detected, a relatively minor one that was eluted from a heparin affinity column with 0.65 M NaCl and a major one that was eluted with 1.1 M NaCl. These activities were not present in wound fluid 1 hr after injury but appeared 1 day after injury, were maximal 2-3 days after injury, and were not detectable by 8 days after injury. The heparin-binding growth factor eluted with 0.65 M NaCl was identified as a platelet-derived growth factor (PDGF)-like activity by the use of specific anti-PDGF neutralizing antibodies. The heparin-binding growth factor eluted with 1.1 M NaCl was shown to be structurally related to heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) by several criteria, including binding to heparin affinity columns and elution with 1.1 M NaCl, competition with the binding of 125I-EGF to the EGF receptor, triggering phosphorylation of the EGF receptor, immunodetection on a Western blot, and stimulation of fibroblast and keratinocyte growth. It was concluded that HB-EGF is a major growth factor component of wound fluid and, since it is mitogenic for fibroblasts and keratinocytes, that it might play an important role in wound healing.

Prognostic factors in clinical trials

Prognostic factors define the study population, help formulate the study objectives, and influence the treatment strategies. They must be accounted for in the study analysis to obtain valid estimates of the treatment differences and to evaluate results across studies. The causal relationship between a prognostic factor and the study endpoint can only be established through prospective randomized study designs. Potential factors discovered through retrospective analysis must be verified to establish their validity. Using such factors prematurely to select patient population and treatment strategy for a new study will not establish the validity of the potentially important factor.

Survey of the prevalence of beta-lactamases amongst 1000 gram-negative bacilli isolated consecutively at the Royal London Hospital

beta-Lactamase expression was examined in 1000 consecutive Gram-negative bacilli isolated from urine, wound swab, sputum or blood specimens received at the Microbiology Laboratory of the Royal London Hospital. This survey, performed between January and April, 1991, followed a similar study undertaken in early 1982. The distribution of species was similar in the two surveys, except that the proportion of Pseudomonas aeruginosa isolates had increased from 11% in 1982 to 17.5% in the present study. This increase was balanced by a decreased proportion of enterobacteria. Amongst plasmid-mediated beta-lactamases, TEM-1 (especially), TEM-2, SHV-1 and OXA types continued to predominate in enterobacteria. Their frequency in Escherichia coli was unchanged (46% in 1991 compared with 43% in 1982), but had increased from 5 to 22% amongst Proteus mirabilis isolates. An apparent decrease in their frequency amongst Enterobacter cloacae isolates, from 48% in 1982 to 17% in 1991, probably reflected changes to strain prevalence rather than enzyme prevalence. Plasmid type beta-lactamases were present in fewer than 2% of P. aeruginosa isolates in both surveys. In the present study, chromosomal beta-lactamase derepression (constitutive hyperproduction) was detected in 10/76 isolates of E. cloacae, Enterobacter aerogenes, Citrobacter freundii, Serratia spp. and Morganella morganii, and in 2/170 P. aeruginosa isolates. These proportions were increased, compared with those seen the 1982 survey, though the significance was borderline (P approximately 0.05; chi 2 test). Extended-spectrum plasmid mediated beta-lactamases, unknown in 1982, were found in 11/70 Klebsiellae pneumoniae isolates in the present study. Ten of these organisms, representing at least five distinct strains, produced TEM-10 enzyme, encoded by a plasmid of c. 90 kb; the remaining organism had an unidentified SHV-derived enzyme.

The relationship of serum IL-6 levels to acute graft-versus-host disease and hepatorenal disease after human bone marrow transplantation

The potential involvement of cytokines in acute graft-versus-host disease led us to analyze interleukin-6 in serial serum sets from 22 allogeneic marrow recipients who developed either grade 3 or 4 GVHD (n = 10), grade 2 GVHD (n = 6), or grade 1 or no diagnosed GVHD (n = 6). A total of 279 serial serum samples taken three times weekly before day 35 were analyzed. Maximum IL-6 levels were greater than 40 U/ml (range, 40-1536 U/ml), 11-40 U/ml, and less than or equal to 10 U/ml for six, eleven, and five patients, respectively. Serum IL-6 peaks were temporally related to onset of GVHD, onset of a syndrome of hepatorenal dysfunction (HRD), or bilateral lung infiltration. Eight of ten patients who developed grade 3 or 4 GVHD overall had IL-6 maxima of greater than 10 U/ml an average of 1.5 +/- 1.8 days before the clinical onset. Fifteen of 17 patients with peak IL-6 levels greater than 10 U/ml developed symptoms of hepatic and renal dysfunction within three days of the peak, while none of five patients with less than or equal to 10 U/ml of Il-6 developed HRD. Regression analysis demonstrated a linkage between the log magnitudes of the serum IL-6 peaks and onset of either GVHD or HRD within three days (P = 0.001). Furthermore, IL-6 peaks tended to precede GVHD onset for the 10 patients whose GVHD onset and IL-6 peak were within three days of each other (P = 0.02). These results, confirmed by both specific bioassay and by IL-6 ELISA, support the idea that acute GVHD in humans involves a cytokine cascade that includes production of IL-6 in addition to the previously reported involvement of tumor necrosis factor alpha and interferon-gamma.

Phase II trial of amonafide in previously treated patients with advanced ovarian cancer: a Southwest Oncology Group study

Twenty-three patients with metastatic or recurrent Stage III or IV epithelial ovarian cancer who were refractory to or relapsed following previous chemotherapy with cisplatin or a cisplatin analog were entered into a phase II study of amonafide. The starting dose of amonafide was 300 mg/m2 delivered daily over 1 hr by intravenous infusion. In the absence of myelosuppression, the dose of amonafide was escalated by increments of 75 mg/m2 to a maximum of 450 mg/m2. There were 19 eligible and 17 fully evaluable patients. Grade 3 or 4 leukopenia occurred in 14 (74%) patients and grade 3 or 4 thrombocytopenia in 6 (32%) patients. No objective complete or partial responses were observed. Four patients had stable disease for 3, 4, 4.5, and 6 months, respectively. Therefore, amonafide in the doses used in the present trial does not have significant activity in previously treated patients with ovarian cancer.

A randomized phase II trial of trimetrexate or didemnin B for the treatment of metastatic or recurrent squamous carcinoma of the uterine cervix: a Southwest Oncology Group trial

Patients with measurable metastatic or recurrent squamous carcinoma of the uterine cervix who had failed prior surgery or radiation therapy were enrolled on this randomized phase II study. Twenty-seven eligible patients were assigned to receive didemnin B at either 2.6 mg/m2 iv every 28 days (sixteen patients) or at 5.6 mg/m2 (eleven patients). Sixteen patients were assigned to receive 12 mg/m2/day iv trimetrexate for 5 days, repeated every 21 days. Toxicity for didemnin B was characterized by nausea and vomiting (78% of patients), anemia (59%), mild diarrhea (11%), and episodic hypersensitivity (three patients). Toxicity for trimetrexate included nausea and vomiting (69%), leukopenia (51%), mild thrombocytopenia (38%), anemia (63%), and diarrhea (31%). No antitumor responses were observed for either agent. Neither trimetrexate nor didemnin B at these doses and schedules is recommended for the treatment of advanced squamous carcinoma of the uterine cervix.

Phase II trial of didemnin-B in advanced epithelial ovarian cancer. A Southwest Oncology Group study

A Phase II study of Didemnin-B, a marine cyclic depsipeptide, was undertaken in patients with progressive epithelial ovarian cancer. The starting dose was 2.6 mg/m2. Fifteen patients received the drug, of whom twelve were evaluable. There were no responses observed in the twelve patients. The two most frequent toxicities were nausea and vomiting and anemia. On the basis of this trial, Didemnin-B is not felt to have significant effect with epithelial ovarian cancer.

Evaluation of amonafide in cervical cancer, phase II. A SWOG study

The Southwest Oncology Group conducted a Phase II study of amonafide in patients with metastatic or recurrent squamous cell cervical cancer. Twelve of the 15 patients were fully evaluable for response and toxicity. There were no clinical responses seen; 2 patients had stable disease while 13 had progressive disease. The major complication of this therapy was myelosuppression. Four patients had life-threatening granulocytopenia (less than 500/microliters), 3 patients had life-threatening leukopenia (less than 1000/microliters), while 2 patients had life-threatening thrombocytopenia (less than 25,000/microliters). Amonafide has significant toxicity but appears to be an inactive drug in metastatic or recurrent squamous cell cancer of the cervix.

Effects of an Asian client-therapist language, ethnicity and gender match on utilization and outcome of therapy

The purpose of this study was to examine the relationship of Asian client-therapist ethnicity, language and gender match on two measures of utilization: number of sessions with primary therapist and dropout from therapy; and one measure of client outcome: admission-discharge difference in Global Assessment Scale (GAS) scores. The sample consisted of 1746 Asian client episodes in Los Angeles County mental health facilities between January 1983 and August 1988. Various types of multiple regression analyses were used to investigate the relationship of language, ethnicity, and gender match to the three dependent variables and to eight socio-demographic variables. Either client-therapist language match or ethnic match significantly increased the number of client sessions with the primary therapist. However, only ethnicity match had a significant effect on dropout rate. Gain in GAS admission-discharge score was not affected by either a client-therapist ethnicity or language match. Gender match had no consistent effect on the dependent variables. Of the covariates examined, only therapist discipline (social worker) had a consistent effect on the dependent variables. It was concluded that both client-therapist language and ethnicity match are important variables affecting the utilization of treatment. Further research will be needed to separate the effects of language and ethnicity on therapy utilization.

Influence of therapist ethnicity and language on therapy outcomes of Southeast Asian clients

The purpose of this study was to examine the relationship of Southeast Asian client-therapist ethnicity and language match on three therapy outcomes: number of sessions with primary therapist, dropout from therapy and admission-discharge difference in Global Assessment Scale (GAS) scores. The sample consisted of 543 Southeast Asian client episodes in Los Angeles County mental health facilities between January 1983 and August 1988. Various types of multiple regression analyses were used to investigate the relationship of language and ethnicity match to the three outcome variables and to eight sociodemographic variables. Either therapist-client language or ethnicity match significantly increased the number of client sessions with the primary therapist. Dropout from therapy was significantly affected by a language match in the Cambodian sample only but the effect was to increase dropout. Neither ethnicity nor language match was significantly related to GAS score gain. Several possible explanations for these findings and their clinical significance were explored.

[Observation on immunogenic effect of intradermal inoculation of small dose of hepatitis B vaccine]

The immunogenic effect of intradermal inoculation of small dose of HB vaccine was evaluated in 120 seronegative villagers (men: 55, women: 65) whose ages were from 3 to 70. These participants were randomly divided into subcutaneous group (I) and intradermal group (II). The results showed that the anti-HBs seroconversion rates and P/N ratios of those who showed the seroconversion for group I, II were 98.4%, 98.3% and 88.0, 89.4, respectively after the third injection. There was no significant difference between the groups in the seroconversion rates and their P/N ratios (P greater than 0.05). It is concluded that in these two groups small doses of HB vaccine have stimulated high immune responses. Intradermal small dose regimen is safe, more economic and will make the HB vaccine available to more people.

Child abuse disposition: concurrences and differences between a hospital team, child protection agency and the court

Ninety-six children admitted to a pediatric ward for maltreatment are described statistically using variables characterizing the child, the family and the type of abuse. Recommendations of the hospital's child protection team in 81 cases are compared to those of the county childrens Services Board and the court. Multiple regression analysis is used to identify which variables influenced the decisions of these three agencies.

Inhibition by diphosphonate compounds of calcification of porcine bioprosthetic heart valve cusps implanted subcutaneously in rats

Calcification limits the long-term success of heart valve bioprostheses fabricated from glutaraldehyde cross-linked porcine aortic valves. The pathophysiology of calcification of bioprostheses has been studied experimentally with subcutaneous implants of the valve cusps in rats; in this preparation, the accumulation of calcific deposits is biochemically and morphologically identical to that occurring in clinical specimens. The objective of the present study was to determine whether mineralization of bioprosthetic valve cusps (BC) subcutaneously implanted in 3-week-old male rats could be inhibited through the use of diphosphonate compounds. Ethanehydroxydiphosphonate (EHDP), administered by daily subcutaneous injection (25 mg/kg/24 hr) for 21 days inhibited calcification (BC Ca++ = 154.9 +/- 4.1), but caused somatic growth retardation and disruption of epiphyseal development. However, local administration of EHDP by osmotic pump (5 mg/kg/24 hr) implanted in direct contact with the cuspal tissue for 14 days prevented BC calcification (BC CA++ = 4.3 +/- 0.7) without adverse effects. Furthermore, EHDP given by osmotic pump had a prolonged effect on reducing calcification, as demonstrated by implants harvested 21 days (BC CA++ = 12.2 +/- 6.4) after the drug supply was exhausted. Finally, BC preincubated in aminopropanehydroxydiphosphonate for 24 hr before 21 day implantation underwent less calcification (CA++ = 24.2 +/- 7.4) than control valves (BC CA++ 126.6 +/- 7.5) with no adverse effects. We conclude that diphosphonates inhibit BC calcification, and that adverse effects of systemic therapy can be avoided by local administration.

Blood flow determination using recursive processing: a digital radiographic method

Temporal filtration of fluoroscopic video sequences is being used as an alternative to pulsed digital subtraction angiography. Using the same image processing architecture and a slight modification in processing logic a parametric image can be synthesized from such a temporally filtered image sequence in virtual real time, i.e., an image sequence that spans T seconds takes exactly T seconds to process. Off-line computer processing is not required. Initial phantom studies imply that the time to maximum opacification (tmax) can be used to determine absolute and relative blood flow with a high confidence level (r greater than .989). Phantom and animal examples are presented.

Dynamic tomographic digital subtraction angiography using temporal filtration

A variation of temporal recursive filtering for intravenous and intra-arterial digital subtraction angiography (DSA) is described. It results in a dynamic tomographic DSA display that may improve intravenous DSA performance by removing the confusion introduced by vessel overlap and reducing the severity of motion artifacts. A conventional circular tomographic apparatus was modified by the addition of a 23-cm image intensifier-television chain and made to run continuously at one revolution each 1.5 seconds. The video output was processed by the recursive filter in a two-step process resulting in a dynamic tomographic display of arterial opacification. Theory and results of initial animal studies are presented.

Digital subtraction angiography using a temporal bandpass filter: initial clinical results

A dual digital memory recursive filtering system provides an effective alternative to digital subtraction imaging by using routine fluoroscopic equipment operated with slightly elevated fluoroscopic technical factors. This is accomplished with relatively inexpensive portable electronic equipment that can be connected to the video output of most modern fluoroscopic systems. Initial clinical experimental studies suggest that the system can produce diagnostic images comparable with pulsed fluoroscopic digital systems. The temporal filtering approach offers a real-time vascular imaging technique that requires no postprocessing and can be used either with arterial or intravenous injections of contrast materials.

Digital subtraction angiography using a temporal bandpass filter: associated patient motion properties

A system for performing real-time digital angiography both intraarterially and intravenously is described. A filtering process, rather than mask subtraction produces diagnostic-quality angiograms using existing fluoroscopic x-ray systems operated continuously (30 frames/sec) at less than 70 kVp and 20 mA. The image degradation effects of patient motion (breathing, swallowing, sudden movement) are dealt with differently from a subtraction approach. Certain periodic patient motions can be accommodated without the need for postprocessing. An analysis of experimental and clinical results of intravenous angiographic studies is presented, with emphasis on patient motion properties.

Digital angiography using a matched filter

Both digital subtraction and recursive filtering schemes have been employed successfully for intravenous and intraarterial arteriography. Either processing method results in an image(s), S, which is a linear combination of discrete images Ij acquired during the flow of iodinated contrast material, i.e., S = Sum of k(j)l(j) from j = 0 to N where k(j) are the weighting coefficients for the N+1 samples. It is shown that for a given set of images {l(j)} there exists a set of weighting coefficients {k(j)} which maximizes the iodine signal to noise ratio and simultaneously removes stationary background anatomy. The k(j) are related to the contrast dilution curve measured over an artery of interest, k(j) = s[j]-Mean(s), where {s[j]} is the set of measured image variations due to the flow of contrast material, and Mean(s), is the mean value of the s[j]. This choice of k(j) defines a matched filter. Compared to subtraction angiography, matched filtering is 4-6 times more dose efficient.

Cycloplegic refraction in esotropic children. Cyclopentolate versus atropine

Retinoscopy was performed on a population of predominantly white esotropic children younger than 5.5 years with cyclopentolate 1% and atropine 1.0%. Atropine 1.0% revealed +0.34 diopters more hyperopia than cyclopentolate 1.0%, when the mean differences between the two drugs were examined. Mean difference analysis would probably indicate that atropine retinoscopy was unnecessary. However, 22% of the children had +1.0 diopters or more of hyperopia uncovered by atropine. This significant subpopulation suggests that in young patients with esotropia, an atropine refraction is essential to uncover the maximum amount of hyperopia. Almost all of this subgroup with +1.00 or greater hyperopia had an initial cyclopentolate retinoscopy of +2.00 diopters or more. Therefore, retinoscopy using atropine cycloplegia becomes even more important in this population. There was a trend for the greater differences to be in children older than age 2 years. However, these values were not statistically significant.

Prolonged survival for melanoma patients with elevated IgM antibody to oncofetal antigen

Antibody directed against a cultured melanoma cell line known to express an oncofetal antigen was measured in sera obtained from patients with stage II melanomas. This study was undertaken to determine if an inhibiting or enhancing effect on tumor growth would be suggested by a positive or negative correlation of antibody levels with tumor recurrence or patient survival. A positive correlation with disease-free interval and survival was detected among patients who had high levels of the IgM class of antibody before and shortly after surgery for state II disease. The IgG class of antibody over the period measured did not correlate consistently with tumor recurrence. Absorption of the IgM antibody with fetal brain confirmed that the dominant detectable reactivity was directed to the oncofetal antigen. The relevance of these findings is related to that of other evidence indicating that immunity to fetal antigens expressed on tumor cells is a participant in host-tumor interaction.

Pulmonary nodules: detection in 1 and 2 cm full lung linear tomography

Pulmonary nodule detection was evaluated in full lung linear tomography at 1 and 2 cm intervals. Three radiologists independently reviewed 1 and 2 tomograms on 26 patients with 39 pulmonary nodules. Decisions made in each case included: (1) no nodule; (2) definite nodule(s); and (3) suspect nodule(s). The presence of nodules was determined by surgery, radiographic follow-up, or observer consensus. A significantly greater number of nodules was detected by all reviewers on the 1 cm tomograms. Of the 39 nodules, 72%-97% were detected as definite and 82%-100% were identified as definite or suspect. Factors relating to nodule detectability and observer performance are discussed. It is recommended that full lung linear tomography be performed at 1 cm intervals.

Semi-microtechnique for the biochemical characterization of anaerobic bacteria

A semi-micromethod is described for characterizing anaerobic bacteria by substrate utilization. Small volumes of individual substrates were placed in the wells of plastic microtiter trays. When heavy inocula and a colorimetric indicator were used, complete results were available after 30 h of incubation. Microtiter trays containing a range of substrates can be stored at -20 degrees C. The method is accurate, economical, and convenient for use in a hospital microbiology laboratory.