Biomedical subjects

K Bolla

Publications and source records attributed to K Bolla.

At least 19 recordsLinked to original sources

PubMed1997

Clinical course of neuropsychological functioning after chronic exposure to organic and inorganic lead.

This case series describes the clinical course (12- to 28-month follow-up) of neuropsychological functioning in 23 workers who had chronic occupational exposure to a mixture of organic and inorganic lead. Significant improvement in performance was seen in 123 tests and deterioration in 323 tests. However, there was no significant change in the majority of tests (1923). Tests that showed deterioration were all tests of psychomotor/motor speed. In addition, 10 of 13 workers who completed a symptom checklist twice reported more frequent physical, cognitive, and affective symptoms at follow-up. This increase in symptoms was associated with psychomotor/motor slowing as compared to initial test performance. Many workers subjectively reported an increased frequency of memory and concentration problems at follow-up, although this change could not be documented objectively. Individual worker demographic and exposure characteristics were not predictive of changes in neuropsychological performance at retest. We propose a psychosocial mechanism to explain the increase in symptom severity and the psychomotor/motor slowing because environmental levels of lead declined during the inter-test interval.

Journal Article↗

PubMed1993

A preliminary study of cortical S2 serotonin receptors and cognitive performance following stroke.

Cortical serotonin receptor binding was measured with positron-emission tomography (PET) in uninjured regions of cortex in 26 stroke patients. Cognitive function was assessed with the Mini-Mental State Exam (MMSE) and a neuropsychological test battery. Left frontal cortex serotonin binding was correlated positively with MMSE total score (r = 0.50, P = 0.01) and with the MMSE concentration, writing, and copying tasks (r = 0.42, 0.56, 0.53, respectively; P < 0.05). Tests of orientation and repetition of difficult phrases were significantly correlated with serotonin binding (r = 0.53 and 0.52, respectively; P < 0.05). These findings suggest that cognitive performance after stroke may be influenced by alterations in the serotonergic system.

Adult↗

PubMed1993

[Speech characteristics of persons wearing full upper and lower prostheses].

We've taken under comparative examination the phonation of people having full upper and lower dentures and the ones having normal teeth. We've tested twenty 51 to 65 years old persons having their dentures at least for a year being pleased with them (well speaking and chewing normally) and twenty persons (without distinction as to sex) having normal teeth normal occlusion. The investigation of the articulation was compiled a lingual corpus consisted of texts of different length (words, word-groups, sentences and text-pieces). This material was suitable for the examination of disorders of the articulation, the pronunciation of the sound combinations, the articulatory problems, and the suprasegmental components (e.g. melody, speech tempo, dynamics of speech). The experimental material was prepared by the following instruments: an VII (Voice Identification, Inc.) 700 series sound spectrograph, an IBM compatible computer with acoustic analytical programs suitable for the investigation of selected sound samples by an A/D (analog/digital) converter, the number of sounds in a second was measured with a 8SO-4 type oscillograph. The results can be summarized as follows: 1. various differences appear among the speech structures of persons having full upper and lower dentures: the labial [b p m], labiodental [v f ], dental, dentialveolar [d t n z s dz ts l r], alveolar [symbol: see text] and prepalatal [symbol: see text] consonants distort principally. 2. From the long consonants the voicelles stops (p: t: k:) are short-ended especially.(ABSTRACT TRUNCATED AT 250 WORDS)

Denture, Complete, Lower↗

PubMed1991

A quantitative approach to the characterization of cumulative and average solvent exposure in paint manufacturing plants.

Previous reports have attributed a range of neurobehavioral effects to low-level, occupational solvent exposure. These studies have generally been limited in their exposure assessments and have specifically lacked good estimates of exposure intensity. In the present study, the authors describe the development of two exposure variables that quantitatively integrate industrial hygiene sampling data with estimates of exposure duration--a cumulative exposure (CE) estimate and a lifetime weighted average exposure (LWAE) estimate. Detailed occupational histories were obtained from 187 workers at two paint manufacturing plants. Historic industrial hygiene sampling data for total hydrocarbons (a composite variable of the major neurotoxic solvents present) were grouped according to 20 uniform, temporally stable exposure zones, which had been defined during plant walk-through surveys. Sampling at the time of the study was used to characterize the few zones for which historic data were limited or unavailable. For each participant, the geometric mean total hydrocarbon level for each exposure zone worked in was multiplied by the duration of employment in that zone; the resulting products were summed over the working lifetime to create the CE variable. The CE variable was divided by the total duration of employment in solvent-exposed jobs to create the LWAE variable. The explanatory value of each participant's LWAE estimate in the regression of simple visual reaction time (a neurobehavioral test previously shown to be affected by chronic solvent exposure) on exposure was compared with that of several other exposure variables, including exposure duration and an exposure variable based on an ordinal ranking of the exposure zones.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical Industry↗

PubMed1989

[Immunologic changes and infection in severely injured patients].

The severity of major surgery determines the extent of immunodeficiency which follows. The most pronounced immunodepression is found after severe blunt trauma; in polytraumatized patients the alterations of many measured parameters correlate with the injury severity score (ISS) i.e. with the severity of the injuries. Infection is also followed by many changes in the immune response. A score including serum concentrations of IgA, beta 2-microglobulin and percentage of monocytes was found to be predictive for the first 3 days after trauma with regard to subsequent occurrence of infection. In the first post-trauma day the lymphocyte-monocyte ratio correlates with the probability of survival or death by infection. Pneumonia occurred in 47% and septicemia in 22% of 150 polytraumatized patients ventilated artificially for more than 24 hours. The first signs of these infections were already present during the first 5 days, i.e. in the period of the most severe immunodeficiency. The preliminary results of a pilot study with immunomodulation by thymopentin are encouraging and show a significant decrease in the frequency of infections.

Humans↗

PubMed1989

Immunomodulation with thymopentin: in vitro studies.

Immunomodulation is interpreted as a temporary alert in a certain part of the immune system. The activation of immune competent cells is presented as a possible basic mechanism of this phenomenon. In the absence of a primary stimulus, immunomodulation remains physiologically silent, but it results in a modified immune response if the corresponding targets are being stimulated. For practical reasons it is suggested that distinctions be made between preventive and regulative immunomodulation. The PWM-induced IgG production of PBMCs was used as a model for the demonstration of the modulatory effect of thymopentin in vitro. Depending on the concentration of thymopentin used in the cultures, this pentapeptide can either stimulate or inhibit the induced IgG production. It also influences PGE2 production and catabolism in the cultures stimulated with PWM. Indomethacin abolishes the modulatory effect of thymopentin on IgG production in this model. It is suggested that the possibility of interactions between an immune modulator and therapeutic approaches which can influence the proportions or functions of the corresponding target cells be considered.

Adjuvants, Immunologic↗

PubMed1989

Intradural spinal cord lesions: Gd-DTPA-enhanced MR imaging.

Twenty-five patients with suspected spinal cord neoplasms were studied with high-field-strength magnetic resonance (MR) imaging (1.5 T) before and after administration of gadolinium diethylenetriamine-pentaacetic acid (DTPA) (gadopentetate dimeglumine). Five patients had enhancing, nonneoplastic lesions, including spinal dural arteriovenous fistulas (AVFs), cord infarction, and chronic arachnoiditis. Fifteen patients had proved spinal cord neoplasms, 13 intramedullary and two extramedullary. Four of the intramedullary tumors were detected only after Gd-DTPA administration; in five others, contrast material enhancement improved observer confidence. Gd-DTPA also demonstrated one dural AVF not detected on precontrast images. Regions of cord ischemia or infarction related to spinal dural AVF also enhanced in three patients. Advantages of Gd-DTPA include the demonstration of small isointense intramedullary tumors and the ability to permit differentiation of tumor from adjacent cord syrinx and solid tumor from postoperative gliosis and arachnoid scarring. Gd-DTPA enhancement is a useful adjunct to high-resolution MR imaging of the spinal cord.

Adult↗

PubMed1988

The immune-enhancing effect of perioperative thymopentin administration in elderly patients undergoing major surgery.

The effects of perioperative administration of thymopentin (TP-5) on in vivo and in vitro measurements of cell-mediated immunity in elderly patients undergoing major surgery were investigated. A placebo-controlled study was conducted in 25 patients (mean age, 67 years) with congenital or acquired heart disease undergoing surgery with cardiopulmonary bypass. Patients were divided into three groups: Group 1 patients were given 50 mg of TP-5 subcutaneously two hours preoperatively. Group 2 patients were given 50 mg of TP-5 subcutaneously two hours preoperatively and 48 hours postoperatively. Group 3 patients were given placebo at corresponding times. Cell-mediated immunity measurements were the in vivo delayed-type hypersensitivity (DTH) response on day 0 and on day 7 to an antigen skin test battery. The in vitro studies included antigen cocktail-induced lymphocyte proliferation of peripheral blood mononuclear cells. The DTH response on day 7 after surgery was significantly suppressed in group 3 patients compared with the preoperative baseline value, while it remained unaltered in group 1 and 2 patients. There was a considerable difference of DTH measurements (number of positive antigen responses and sum of their mean diameters) between group 2 and 3 patients. Antigen cocktail-induced lymphocyte proliferation, following initial suppression in the majority of patients, was significantly different between the placebo group and patients in group 2 on day 7 after surgery. The data indicate that perioperative administration of TP-5 might be of considerable clinical utility in preventing a defective cellular immune response.

Adjuvants, Immunologic↗

PubMed1988

Thymopentin treatment in genital warts of long duration.

The immunomodulatory effect of thymopentin as therapy in genital warts of long duration and the proliferative responses of the patient's peripheral blood mononuclear cells were investigated in this pilot study. The observations in 6 patients suggest that subcutaneous injections of thymopentin (50 mg) beneficially influence the systems of therapy-resistant genital warts. The small number of patients and controls used in the assessment of the proliferation responses allows only a descriptive analysis of the results, but definitive trends can be observed in the Con A- and PHA-induced proliferation tests. These clinical observations, the theoretical considerations, and the low rate of side effects of thymopentin reported also by other investigators all emphasize the importance of further well-controlled double-blind studies on the treatment of genital warts with thymopentin.

Adult↗

PubMed1987

Influence of thymopentin on postsurgical immune deficiency: a clinical pilot study.

The effect of a single dose (50 mg) of thymopentin, administered subcutaneously, on antigen-induced proliferation of peripheral blood mononuclear cells (PBMCs) was investigated in 25 volunteers (all over 50 years of age) and in nine patients undergoing major surgery. Blood samples from another nine patients having the same type of surgery were used as control in the second trial. A statistically significant increase in the proliferative response was observed in the group of volunteers two hours after thymopentin administration. This increment was not demonstrable as significant 24 h later. In contrast to this observation, the surgical procedure-induced significant decrement in the proliferation of PBMCs observed on the first and third postoperative days did not occur in the thymopentin-treated patients on the first postoperative day. This preventive effect of the single dose of thymopentin administered two hours before surgery was no longer demonstrable on the third postoperative day. Further studies are ongoing in order to establish a treatment regimen with thymopentin for the therapy of trauma-induced immune deficiencies.

Adjuvants, Immunologic↗

PubMed1985

Treatment of active rheumatoid arthritis with slow intravenous injections of thymopentin. A double-blind placebo-controlled randomised study.

41 patients with active rheumatoid arthritis entered a placebo-controlled double-blind randomised study in which 21 received slow intravenous injections (given in fractions over 10 min) of thymopentin (TP-5) 50 mg 3 times a week for 3 consecutive weeks and 20 received placebo in the same way. After 3 weeks of treatment the TP-5 group showed improvement (p less than 0.05 or p less than 0.01) in all but one of the clinical variables tested. There was improvement in the number of joints painful at rest, the number of joints painful on motion, scores for tenderness on pressure and swollen joints, severity of pain on awakening and morning stiffness, and right-hand grip strength; left-hand grip strength remained unchanged. In the placebo group, only morning stiffness improved significantly. The intergroup comparisons showed that thymopentin was significantly better than placebo in reducing tenderness, joint swelling, severity of pain on awakening, and disease activity. 4 weeks after the end of the TP-5 therapy, the improvement was still present although there was a trend towards relapses. No significant modifications occurred in any of the laboratory variables tested and only minor side-effects were experienced by either group.

Adult↗

PubMed1985

Prevention of recurrences in frequently relapsing herpes labialis with thymopentin. A randomized double-blind placebo-controlled multicenter study.

The present randomized, placebo-controlled double-blind multicenter study included a population of 36 subjects with frequent recurrences (at least once a month) of herpes labialis. Most of the patients had failed to respond adequately to previous treatment with other therapeutic tools, including acyclovir. Either 50 mg of thymopentin or of placebo was administered 3 times a week, by the subcutaneous route, for 6 weeks. Subsequently, the patients were observed for nearly 6 months on the average. The results achieved with thymopentin for the individual parameters were significantly superior to those obtained with placebo; thus significant improvement was seen in patients on thymopentin in the duration of the longest symptomfree period (prolonged from 2.1 weeks to 20.9 weeks, p = 0.000), in the number of relapses (reduced from 1.6 to 0.4 episodes/month, p = 0.001), and in the total duration of herpes symptoms per month (shortened from 2.0 to 0.3 weeks, p = 0.000). Placebo treatment also resulted in considerable improvement (p less than 0.05 or 0.01), but was significantly inferior to the improvement obtained with thymopentin. The longest symptomfree period in the placebo group was prolonged from 2.4 to 11.2 weeks. The number of relapses per month was reduced from 1.4 to 0.8, and the total duration of herpes symptoms per month from 2 to 0.9 weeks. The results of intergroup analyses, in which the observed parameters and the improvement achieved in either group were compared, significantly favored thymopentin treatment. The effect of thymopentin was in all but one parameters superior to that of placebo and highly significant (p less than 0.01).

Adjuvants, Immunologic↗

PubMed1985

Effect of thymopentin on the mortality and immune response after an experimental herpes simplex infection in mice.

The effect of thymopentin on the mortality rate of mice treated with lethal doses (LD90) of herpes virus 2 and on the cytotoxic T cell activity after sublethal doses (LD10) of herpes virus was investigated in two series of experiments. Doses of 1, 0.1 or 0.01 ng of thymopentin per g/mouse were administered i.p. in each experiment, either 3 days before, 3 days (66 h) after, or 3 and 6 days after the herpes virus infection. The cumulative mortality rate was evaluated 10 days after the infection. Cytotoxic T cell activity was measured 3, 7 and 14 days after the infection. The 0.1-ng dose of thymopentin reduced the mortality rate to less than 50% (p = 0.0000) if it was administered 3 days before the infection. A single injection of any dose after infection did not reduce the mortality at all, while two injections of 0.1 ng reduced it by about 25% (p = 0.0038). A 1-ng dose showed a mild but significant reduction (p = 0.0313) if it was applied 3 days before the infection. The cytotoxic T cell activity was either not influenced or significantly modified (p less than 0.05), i.e. increased or decreased as compared to the control, depending on the dose and timing of thymopentin. A correlation between increased cytotoxic T cell activity and protection against mortality can be demonstrated, while no protection was observed in dose regimens where the cytotoxic T cell activity became reduced. The results are discussed in connection with earlier clinical studies in which the beneficial effect of thymopentin has been demonstrated in frequently relapsing herpes labialis and herpes genitalis patients.

Adjuvants, Immunologic↗

PubMed1985

Thymopentin treatment in AIDS and pre-AIDS patients.

Three pilot studies testing thymopentin in AIDS patients are presented. One study included 5 patients with the full-blown syndrome, all treated with 50 mg thymopentin 3 times a week by intravenous slow infusion; no immunologically nor clinically positive results were observed, indicating that the T cell pool in such patients is severely depleted. Six other patients with the prodromal stage of AIDS were treated 1 month with 50 mg thymopentin administered as an intravenous bolus injection 3 times weekly and thereafter for another month with same dose regimen as intravenous slow infusions. The patients on infusion therapy experienced statistically significant immunological improvements; these positive findings were paralleled with an improvement of the patients' clinical condition. These positive responses persisted for an average of 8 months. In another group of 5 pre-AIDS patients thymopentin was administered via the subcutaneous route using 15 mg 3 times weekly; only 1 patient revealed immunological and clinical improvement. In summary, only patients with the pre-AIDS syndrome are likely to benefit from immunomodulation therapy with thymopentin, and the mode of administration seems to be crucial.

Acquired Immunodeficiency Syndrome↗

PubMed1985

Thymopentin treatment in patients with chemotherapy-resistant lepromatous leprosy.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae; it is chiefly involving the skin and peripheral nerves. In lepromatous leprosy there are widespread loose infiltrates with M. leprae multiplying extensively in the skin macrophages and Schwann cells of peripheral nerves. Such patients reveal a decrease of circulating T helper cells, which is still more pronounced in the cutaneous lesions. Due to the ever increasing bacterial resistance to classical dapsone and combined chemotherapy as well, an immunomodulatory approach seemed reasonable: Eight patients with long-lasting (5-40 years) disease who had become resistant to combined chemotherapy were treated with thymopentin, 50 mg s.c., 3 times weekly for 5 weeks and thereafter combined with dapsone and clofazimine for 5 months. During the trial a statistically significant increase in E-rosette-forming cells (p less than 0.05) was observed, along with a steady improvement of the bacterial status of the nasal mucus. Although the skin lesions did not disappear within the observation period of the study, it is important to realize that long-term improvement of such lesions is always initiated by clearance of bacilli from the nasal mucus, hence, thymopentin treatment appears to be a promising approach to chemotherapy-resistant lepromatous lepra.

Adjuvants, Immunologic↗

PubMed1985

Rationale for thymopentin as therapeutic agent in rheumatoid arthritis.

Etiology and pathogenesis of rheumatoid arthritis (RA) is reviewed, with special emphasis on immunological factors. A common feature in active RA seems to be the decreased T cell suppressor/cytotoxic response, also reflected in an increased OKT4/OKT8 ratio. As the presence of several subgroups in patients is possible, the therapeutic approach may differ accordingly. Different disease-modifying antirheumatic drugs (DMARDs) are discussed in this context; their most characteristic features are slow onset of action (i.e., after several months) and improvement in immunological parameters. Although thymopentin does possess the latter property, it is not considered a DMARD at the present time. The action of thymopentin sets in within a few weeks, and it is speculated whether this may be due to its possible hormonal effects (via beta-endorphins, prostaglandins, etc.).

Adjuvants, Immunologic↗

PubMed1985

Some observations on various dose regimens of thymopentin treatment in rheumatoid arthritis.

Eight patients suffering from active rheumatoid arthritis were treated with thymopentin, 50 mg, administered as fractionated intravenous infusion over 10 min 3 times weekly for 3-20 weeks. Seven patients experienced clear-cut amelioration of symptoms and signs after just 2-4 weeks of treatment, and this improvement lasted for 6-8 weeks after thymopentin had been discontinued. Comparable positive results were observed in 2 patients who later continued thymopentin therapy by subcutaneous administration. Several subcutaneous dose regimens were tried; the optimal response appears to be achieved with 100-150 mg three times weekly and 150-200 mg twice a week, respectively. Because the subcutaneous therapeutic approach is more attractive to the patient-and also more practical for the physician-it should be investigated further.

Adjuvants, Immunologic↗

PubMed1985

Confirmative study of the effectiveness of thymopentin in active rheumatoid arthritis.

Forty-one patients with active rheumatoid arthritis entered a controlled double-blind randomized study. Of these patients, 21 received prolonged intravenous injections (10 min) of thymopentin 50 mg three times a week for 3 consecutive weeks, whereas 20 received placebo. Both groups were comparable with regard to clinical parameters. No immunological tests were performed. Analysis of the results after 3 weeks showed that the improvement in the thymopentin group was statistically significant (p less than 0.05 or p less than 0.01) for all clinical parameters, except for the left-hand grip strength. On the other hand, no significant improvement was observed for any parameter, except morning stiffness, in the patients on placebo. The intergroup comparison showed statistically significant differences, favoring thymopentin over placebo treatment, in the Ritchie index, the scores of swollen joints, the assessment of severity of pain, and the scores for changes in the activity of the disease. The present placebo-controlled double blind study thus confirms the positive results generated in a similar open study, i.e., the beneficial therapeutic effect of prolonged intravenous injections of thymopentin in patients with severe rheumatoid arthritis. The drug appears to be safe at the dose regimen used.

Adjuvants, Immunologic↗